U.S. patent application number 11/030464 was filed with the patent office on 2005-09-29 for secreted and transmembrane polypeptides and nucleic acids encoding the same.
This patent application is currently assigned to GENENTECH, INC.. Invention is credited to Smith, Victoria, Watanabe, Colin K..
Application Number | 20050214819 11/030464 |
Document ID | / |
Family ID | 21978554 |
Filed Date | 2005-09-29 |
United States Patent
Application |
20050214819 |
Kind Code |
A1 |
Smith, Victoria ; et
al. |
September 29, 2005 |
Secreted and transmembrane polypeptides and nucleic acids encoding
the same
Abstract
The present invention is directed to novel polypeptides and to
nucleic acid molecules encoding those polypeptides. Also provided
herein are vectors and host cells comprising those nucleic acid
sequences, chimeric polypeptide molecules comprising the
polypeptides of the present invention fused to heterologous
polypeptide sequences, antibodies which bind to the polypeptides of
the present invention and to methods for producing the polypeptides
of the present invention.
Inventors: |
Smith, Victoria;
(Burlingame, CA) ; Watanabe, Colin K.; (Moraga,
CA) |
Correspondence
Address: |
HELLER EHRMAN LLP
275 MIDDLEFIELD ROAD
MENLO PARK
CA
94025-3506
US
|
Assignee: |
GENENTECH, INC.
SOUTH SAN FRANCISCO
CA
|
Family ID: |
21978554 |
Appl. No.: |
11/030464 |
Filed: |
January 5, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11030464 |
Jan 5, 2005 |
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10199464 |
Jul 19, 2002 |
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10199464 |
Jul 19, 2002 |
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10052586 |
Jan 15, 2002 |
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10052586 |
Jan 15, 2002 |
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PCT/US01/06520 |
Feb 28, 2001 |
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PCT/US01/06520 |
Feb 28, 2001 |
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09380137 |
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09380137 |
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PCT/US99/12252 |
Jun 2, 1999 |
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60090676 |
Jun 25, 1998 |
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Current U.S.
Class: |
435/6.17 ;
435/7.23 |
Current CPC
Class: |
A01K 2217/075 20130101;
C12Q 2563/131 20130101; C12Q 2527/137 20130101; C07K 14/82
20130101; C12Q 1/6883 20130101; A61K 38/00 20130101; C12Q 1/6816
20130101; C07K 14/705 20130101; C12Q 1/6816 20130101; A01K 2227/105
20130101; C12Q 2600/158 20130101; G01N 33/57423 20130101; C07K
2319/30 20130101; G01N 33/5308 20130101; G01N 2500/00 20130101;
G01N 33/57434 20130101; C12Q 1/6886 20130101; C07K 14/4748
20130101; G01N 33/57419 20130101; C12Q 2600/136 20130101; G01N
33/574 20130101; G01N 33/57484 20130101; G01N 33/57492 20130101;
C07K 16/28 20130101; G01N 33/57488 20130101; G01N 33/5082 20130101;
C07K 14/47 20130101 |
Class at
Publication: |
435/006 ;
435/007.23 |
International
Class: |
C12Q 001/68; G01N
033/574 |
Claims
What is claimed is:
1. A diagnostic method, comprising determining, in a test
biological sample obtained from a mammalian subject, the level of
nucleic acid encoding a PRO839 polypeptide of SEQ ID NO:2 relative
to the level of said nucleic acid in a corresponding normal
biological sample wherein increased level of said nucleic acid in
the test biological sample is indicative that the test biological
sample contains cancerous cells.
2. The method of claim 1 wherein the test and normal biological
samples are tissue samples.
3. The method of claim 2 wherein the test tissue sample is from
colon tissue.
4. The method of claim 3 wherein the normal biological sample is
from the same type of tissue as the test biological sample.
5. The method of claim 4 wherein the normal biological sample is an
epithelial tissue sample from a combination of tissues.
6. The method of claim 5 wherein epithelial tissue sample includes
epithelial cells from colon tissue.
7. The method of claim 1 wherein the nucleic acid levels are
determined by hybridization of nucleic acid obtained from the test
and normal biological samples to one or more probes specific for
the nucleic acid encoding PRO839.
8. The method of claim 6 wherein hybridization is performed under
stringent conditions.
9. The method of claim 8 wherein said stringent conditions use 50%
formamide, 5.times.SSC, 50 mM sodium phosphate (pH 6.8), 0.1%
sodium pyrophosphate, 5.times. Denhardt's solution, sonicated
salmon sperm DNA (50 .mu.g/ml), 0.1% SDS, and 10% dextran sulfate
at 42.degree. C., with washes at 42.degree. C. in 0.2.times.SSC and
50% formamide at 55.degree. C., followed by a wash comprising of
0.1.times.SSC containing EDTA at 55.degree. C.
10. The method of claim 7 wherein the nucleic acids obtained from
the test and normal biological samples are cDNAs.
11. The method of claim 10 wherein the nucleic acids obtained from
the test and normal biological samples are placed on
microarrays.
12. A diagnostic method comprising determining the expression level
of the PRO839 polypeptide of SEQ ID NO:2 in test biological sample
relative to a normal biological sample, wherein overexpression of
said polypeptide in the test biological sample is indicative that
the sample contains cancerous cells.
13. The method of claim 12 wherein the test and normal biological
samples are tissue samples.
14. The method of claim 13 wherein the test tissue sample is from
colon tissue.
15. The method of claim 14 wherein overexpression is detected with
an antibody that specifically binds to the PRO839 polypeptide.
16. The method of claim 15 wherein said antibody is a monoclonal
antibody.
17. The method of claim 16 wherein said antibody is a humanized
antibody.
18. The method of claim 17 wherein said antibody is an antibody
fragment.
19. The method of claim 18 wherein said antibody is labeled.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of, and claims priority
under 35 U.S.C. .sctn.120, to U.S. patent application Ser. No.
10/199,464 filed Jul. 19, 2002, which is a continuation of, and
claims priority under 35 U.S.C. .sctn.120, patent application Ser.
No. 10/052,586 filed Jan. 15, 2002, which is a continuation of, and
claims priority under 35 USC .sctn.120 to PCT Application
PCT/US01/06520 filed Feb. 28, 2001, which is a continuation-in-part
of, and claims priority under 35 U.S.C. .sctn.120 to, U.S.
application Ser. No. 09/380,137 filed Aug. 25, 1999, now abandoned,
which is the National Stage filed under 35 U.S.C. .sctn.371 of PCT
Application PCT/US99/12252 filed Jun. 2, 1999, which claims
priority under 35 U.S.C. .sctn.119 to U.S. provisional application
60/090,676 filed Jun. 25, 1998, the entire disclosures of which are
hereby expressly incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to the
identification and isolation of novel DNA and to the recombinant
production of novel polypeptides.
BACKGROUND OF THE INVENTION
[0003] Extracellular proteins play important roles in, among other
things, the formation, differentiation and maintenance of
multicellular organisms. The fate of many individual cells, e.g.,
proliferation, migration, differentiation, or interaction with
other cells, is typically governed by information received from
other cells and/or the immediate environment. This information is
often transmitted by secreted polypeptides (for instance, mitogenic
factors, survival factors, cytotoxic factors, differentiation
factors, neuropeptides, and hormones) which are, in turn, received
and interpreted by diverse cell receptors or membrane-bound
proteins. These secreted polypeptides or signaling molecules
normally pass through the cellular secretory pathway to reach their
site of action in the extracellular environment.
[0004] Secreted proteins have various industrial applications,
including as pharmaceuticals, diagnostics, biosensors and
bioreactors. Most protein drugs available at present, such as
thrombolytic agents, interferons, interleukins, erythropoietins,
colony stimulating factors, and various other cytokines, are
secretory proteins. Their receptors, which are membrane proteins,
also have potential as therapeutic or diagnostic agents. Efforts
are being undertaken by both industry and academia to identify new,
native secreted proteins. Many efforts are focused on the screening
of mammalian recombinant DNA libraries to identify the coding
sequences for novel secreted proteins. Examples of screening
methods and techniques are described in the literature [see, for
example, Klein et al., Proc. Natl. Acad. Sci. 93:7108-7113 (1996);
U.S. Pat. No. 5,536,637)].
[0005] Membrane-bound proteins and receptors can play important
roles in, among other things, the formation, differentiation and
maintenance of multicellular organisms. The fate of many individual
cells, e.g., proliferation, migration, differentiation, or
interaction with other cells, is typically governed by information
received from other cells and/or the immediate environment. This
information is often transmitted by secreted polypeptides (for
instance, mitogenic factors, survival factors, cytotoxic factors,
differentiation factors, neuropeptides, and hormones) which are, in
turn, received and interpreted by diverse cell receptors or
membrane-bound proteins. Such membrane-bound proteins and cell
receptors include, but are not limited to, cytokine receptors,
receptor kinases, receptor phosphatases, receptors involved in
cell-cell interactions, and cellular adhesin molecules like
selectins and integrins. For instance, transduction of signals that
regulate cell growth and differentiation is regulated in part by
phosphorylation of various cellular proteins. Protein tyrosine
kinases, enzymes that catalyze that process, can also act as growth
factor receptors. Examples include fibroblast growth factor
receptor and nerve growth factor receptor.
[0006] Membrane-bound proteins and receptor molecules have various
industrial applications, including as pharmaceutical and diagnostic
agents. Receptor immunoadhesins, for instance, can be employed as
therapeutic agents to block receptor-ligand interactions. The
membrane-bound proteins can also be employed for screening of
potential peptide or small molecule inhibitors of the relevant
receptor/ligand interaction.
[0007] Efforts are being undertaken by both industry and academia
to identify new, native receptor or membrane-bound proteins. Many
efforts are focused on the screening of mammalian recombinant DNA
libraries to identify the coding sequences for novel receptor or
membrane-bound proteins.
SUMMARY OF THE INVENTION
[0008] In one embodiment, the invention provides an isolated
nucleic acid molecule comprising a nucleotide sequence that encodes
a PRO polypeptide.
[0009] In one aspect, the isolated nucleic acid molecule comprises
a nucleotide sequence having at least about 80% nucleic acid
sequence identity, alternatively at least about 81% nucleic acid
sequence identity, alternatively at least about 82% nucleic acid
sequence identity, alternatively at least about 83% nucleic acid
sequence identity, alternatively at least about 84% nucleic acid
sequence identity, alternatively at least about 85% nucleic acid
sequence identity, alternatively at least about 86% nucleic acid
sequence identity, alternatively at least about 87% nucleic acid
sequence identity, alternatively at least about 88% nucleic acid
sequence identity, alternatively at least about 89% nucleic acid
sequence identity, alternatively at least about 90% nucleic acid
sequence identity, alternatively at least about 91% nucleic acid
sequence identity, alternatively at least about 92% nucleic acid
sequence identity, alternatively at least about 93% nucleic acid
sequence identity, alternatively at least about 94% nucleic acid
sequence identity, alternatively at least about 95% nucleic acid
sequence identity, alternatively at least about 96% nucleic acid
sequence identity, alternatively at least about 97% nucleic acid
sequence identity, alternatively at least about 98% nucleic acid
sequence identity and alternatively at least about 99% nucleic acid
sequence identity to (a) a DNA molecule encoding a PRO polypeptide
having a full-length amino acid sequence as disclosed herein, an
amino acid sequence lacking the signal peptide as disclosed herein,
an extracellular domain of a transmembrane protein, with or without
the signal peptide, as disclosed herein or any other specifically
defined fragment of the full-length amino acid sequence as
disclosed herein, or (b) the complement of the DNA molecule of
(a).
[0010] In other aspects, the isolated nucleic acid molecule
comprises a nucleotide sequence having at least about 80% nucleic
acid sequence identity, alternatively at least about 81% nucleic
acid sequence identity, alternatively at least about 82% nucleic
acid sequence identity, alternatively at least about 83% nucleic
acid sequence identity, alternatively at least about 84% nucleic
acid sequence identity, alternatively at least about 85% nucleic
acid sequence identity, alternatively at least about 86% nucleic
acid sequence identity, alternatively at least about 87% nucleic
acid sequence identity, alternatively at least about 88% nucleic
acid sequence identity, alternatively at least about 89% nucleic
acid sequence identity, alternatively at least about 90% nucleic
acid sequence identity, alternatively at least about 91% nucleic
acid sequence identity, alternatively at least about 92% nucleic
acid sequence identity, alternatively at least about 93% nucleic
acid sequence identity, alternatively at least about 94% nucleic
acid sequence identity, alternatively at least about 95% nucleic
acid sequence identity, alternatively at least about 96% nucleic
acid sequence identity, alternatively at least about 97% nucleic
acid sequence identity, alternatively at least about 98% nucleic
acid sequence identity and alternatively at least about 99% nucleic
acid sequence identity to (a) a DNA molecule comprising the coding
sequence of a full-length PRO polypeptide cDNA as disclosed herein,
the coding sequence of a PRO polypeptide lacking the signal peptide
as disclosed herein, the coding sequence of an extracellular domain
of a transmembrane PRO polypeptide, with or without the signal
peptide, as disclosed herein or the coding sequence of any other
specifically defined fragment of the full-length amino acid
sequence as disclosed herein, or (b) the complement of the DNA
molecule of (a).
[0011] In a further aspect, the invention concerns an isolated
nucleic acid molecule comprising a nucleotide sequence having at
least about 80% nucleic acid sequence identity, alternatively at
least about 81% nucleic acid sequence identity, alternatively at
least about 82% nucleic acid sequence identity, alternatively at
least about 83% nucleic acid sequence identity, alternatively at
least about 84% nucleic acid sequence identity, alternatively at
least about 85% nucleic acid sequence identity, alternatively at
least about 86% nucleic acid sequence identity, alternatively at
least about 87% nucleic acid sequence identity, alternatively at
least about 88% nucleic acid sequence identity, alternatively at
least about 89% nucleic acid sequence identity, alternatively at
least about 90% nucleic acid sequence identity, alternatively at
least about 91% nucleic acid sequence identity, alternatively at
least about 92% nucleic acid sequence identity, alternatively at
least about 93% nucleic acid sequence identity, alternatively at
least about 94% nucleic acid sequence identity, alternatively at
least about 95% nucleic acid sequence identity, alternatively at
least about 96% nucleic acid sequence identity, alternatively at
least about 97% nucleic acid sequence identity, alternatively at
least about 98% nucleic acid sequence identity and alternatively at
least about 99% nucleic acid sequence identity to (a) a DNA
molecule that encodes the same mature polypeptide encoded by any of
the human protein cDNAs deposited with the ATCC as disclosed
herein, or (b) the complement of the DNA molecule of (a).
[0012] Another aspect the invention provides an isolated nucleic
acid molecule comprising a nucleotide sequence encoding a PRO
polypeptide which is either transmembrane domain-deleted or
transmembrane domain-inactivated, or is complementary to such
encoding nucleotide sequence, wherein the transmembrane domain(s)
of such polypeptide are disclosed herein. Therefore, soluble
extracellular domains of the herein described PRO polypeptides are
contemplated.
[0013] Another embodiment is directed to fragments of a PRO
polypeptide coding sequence, or the complement thereof, that may
find use as, for example, hybridization probes, for encoding
fragments of a PRO polypeptide that may optionally encode a
polypeptide comprising a binding site for an anti-PRO antibody or
as antisense oligonucleotide probes. Such nucleic acid fragments
are usually at least about 10 nucleotides in length, alternatively
at least about 15 nucleotides in length, alternatively at least
about 20 nucleotides in length, alternatively at least about 30
nucleotides in length, alternatively at least about 40 nucleotides
in length, alternatively at least about 50 nucleotides in length,
alternatively at least about 60 nucleotides in length,
alternatively at least about 70 nucleotides in length,
alternatively at least about 80 nucleotides in length,
alternatively at least about 90 nucleotides in length,
alternatively at least about 100 nucleotides in length,
alternatively at least about 110 nucleotides in length,
alternatively at least about 120 nucleotides in length,
alternatively at least about 130 nucleotides in length,
alternatively at least about 140 nucleotides in length,
alternatively at least about 150 nucleotides in length,
alternatively at least about 160 nucleotides in length,
alternatively at least about 170 nucleotides in length,
alternatively at least about 180 nucleotides in length,
alternatively at least about 190 nucleotides in length,
alternatively at least about 200 nucleotides in length,
alternatively at least about 250 nucleotides in length,
alternatively at least about 300 nucleotides in length,
alternatively at least about 350 nucleotides in length,
alternatively at least about 400 nucleotides in length,
alternatively at least about 450 nucleotides in length,
alternatively at least about 500 nucleotides in length,
alternatively at least about 600 nucleotides in length,
alternatively at least about 700 nucleotides in length,
alternatively at least about 800 nucleotides in length,
alternatively at least about 900 nucleotides in length and
alternatively at least about 1000 nucleotides in length, wherein in
this context the term "about" means the referenced nucleotide
sequence length plus or minus 10% of that referenced length. It is
noted that novel fragments of a PRO polypeptide-encoding nucleotide
sequence may be determined in a routine manner by aligning the PRO
polypeptide-encoding nucleotide sequence with other known
nucleotide sequences using any of a number of well known sequence
alignment programs and determining which PRO polypeptide-encoding
nucleotide sequence fragment(s) are novel. All of such PRO
polypeptide-encoding nucleotide sequences are contemplated herein.
Also contemplated are the PRO polypeptide fragments encoded by
these nucleotide molecule fragments, preferably those PRO
polypeptide fragments that comprise a binding site for an anti-PRO
antibody.
[0014] In another embodiment, the invention provides isolated PRO
polypeptide encoded by any of the isolated nucleic acid sequences
hereinabove identified.
[0015] In a certain aspect, the invention concerns an isolated PRO
polypeptide, comprising an amino acid sequence having at least
about 80% amino acid sequence identity, alternatively at least
about 81% amino acid sequence identity, alternatively at least
about 82% amino acid sequence identity, alternatively at least
about 83% amino acid sequence identity, alternatively at least
about 84% amino acid sequence identity, alternatively at least
about 85% amino acid sequence identity, alternatively at least
about 86% amino acid sequence identity, alternatively at least
about 87% amino acid sequence identity, alternatively at least
about 88% amino acid sequence identity, alternatively at least
about 89% amino acid sequence identity, alternatively at least
about 90% amino acid sequence identity, alternatively at least
about 91% amino acid sequence identity, alternatively at least
about 92% amino acid sequence identity, alternatively at least
about 93% amino acid sequence identity, alternatively at least
about 94% amino acid sequence identity, alternatively at least
about 95% amino acid sequence identity, alternatively at least
about 96% amino acid sequence identity, alternatively at least
about 97% amino acid sequence identity, alternatively at least
about 98% amino acid sequence identity and alternatively at least
about 99% amino acid sequence identity to a PRO polypeptide having
a full-length amino acid sequence as disclosed herein, an amino
acid sequence lacking the signal peptide as disclosed herein, an
extracellular domain of a transmembrane protein, with or without
the signal peptide, as disclosed herein or any other specifically
defined fragment of the full-length amino acid sequence as
disclosed herein.
[0016] In a further aspect, the invention concerns an isolated PRO
polypeptide comprising an amino acid sequence having at least about
80% amino acid sequence identity, alternatively at least about 81%
amino acid sequence identity, alternatively at least about 82%
amino acid sequence identity, alternatively at least about 83%
amino acid sequence identity, alternatively at least about 84%
amino acid sequence identity, alternatively at least about 85%
amino acid sequence identity, alternatively at least about 86%
amino acid sequence identity, alternatively at least about 87%
amino acid sequence identity, alternatively at least about 88%
amino acid sequence identity, alternatively at least about 89%
amino acid sequence identity, alternatively at least about 90%
amino acid sequence identity, alternatively at least about 91%
amino acid sequence identity, alternatively at least about 92%
amino acid sequence identity, alternatively at least about 93%
amino acid sequence identity, alternatively at least about 94%
amino acid sequence identity, alternatively at least about 95%
amino acid sequence identity, alternatively at least about 96%
amino acid sequence identity, alternatively at least about 97%
amino acid sequence identity, alternatively at least about 98%
amino acid sequence identity and alternatively at least about 99%
amino acid sequence identity to an amino acid sequence encoded by
any of the human protein cDNAs deposited with the ATCC as disclosed
herein.
[0017] In a specific aspect, the invention provides an isolated PRO
polypeptide without the N-terminal signal sequence and/or the
initiating methionine and is encoded by a nucleotide sequence that
encodes such an amino acid sequence as hereinbefore described.
Processes for producing the same are also herein described, wherein
those processes comprise culturing a host cell comprising a vector
which comprises the appropriate encoding nucleic acid molecule
under conditions suitable for expression of the PRO polypeptide and
recovering the PRO polypeptide from the cell culture.
[0018] Another aspect the invention provides an isolated PRO
polypeptide which is either transmembrane domain-deleted or
transmembrane domain-inactivated. Processes for producing the same
are also herein described, wherein those processes comprise
culturing a host cell comprising a vector which comprises the
appropriate encoding nucleic acid molecule under conditions
suitable for expression of the PRO polypeptide and recovering the
PRO polypeptide from the cell culture.
[0019] In yet another embodiment, the invention concerns agonists
and antagonists of a native PRO polypeptide as defined herein. In a
particular embodiment, the agonist or antagonist is an anti-PRO
antibody or a small molecule.
[0020] In a further embodiment, the invention concerns a method of
identifying agonists or antagonists to a PRO polypeptide which
comprise contacting the PRO polypeptide with a candidate molecule
and monitoring a biological activity mediated by said PRO
polypeptide. Preferably, the PRO polypeptide is a native PRO
polypeptide.
[0021] In a still further embodiment, the invention concerns a
composition of matter comprising a PRO polypeptide, or an agonist
or antagonist of a PRO polypeptide as herein described, or an
anti-PRO antibody, in combination with a carrier. Optionally, the
carrier is a pharmaceutically acceptable carrier.
[0022] Another embodiment of the present invention is directed to
the use of a PRO polypeptide, or an agonist or antagonist thereof
as hereinbefore described, or an anti-PRO antibody, for the
preparation of a medicament useful in the treatment of a condition
which is responsive to the PRO polypeptide, an agonist or
antagonist thereof or an anti-PRO antibody.
[0023] In other embodiments of the present invention, the invention
provides vectors comprising DNA encoding any of the herein
described polypeptides. Host cell comprising any such vector are
also provided. By way of example, the host cells may be CHO cells,
E. coli, or yeast. A process for producing any of the herein
described polypeptides is further provided and comprises culturing
host cells under conditions suitable for expression of the desired
polypeptide and recovering the desired polypeptide from the cell
culture.
[0024] In other embodiments, the invention provides chimeric
molecules comprising any of the herein described polypeptides fused
to a heterologous polypeptide or amino acid sequence. Example of
such chimeric molecules comprise any of the herein described
polypeptides fused to an epitope tag sequence or a Fc region of an
immunoglobulin.
[0025] In another embodiment, the invention provides an antibody
which binds, preferably specifically, to any of the above or below
described polypeptides. Optionally, the antibody is a monoclonal
antibody, humanized antibody, antibody fragment or single-chain
antibody.
[0026] In yet other embodiments, the invention provides
oligonucleotide probes which may be useful for isolating genomic
and cDNA nucleotide sequences, measuring or detecting expression of
an associated gene or as antisense probes, wherein those probes may
be derived from any of the above or below described nucleotide
sequences. Preferred probe lengths are described above.
[0027] In yet other embodiments, the present invention is directed
to methods of using the PRO polypeptides of the present invention
for a variety of uses based upon the functional biological assay
data presented in the Examples below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 shows a nucleotide sequence (SEQ ID NO:1) of a native
sequence PRO839 cDNA, wherein SEQ ID NO:1 is a clone designated
herein as "DNA56859-1445".
[0029] FIG. 2 shows the amino acid sequence (SEQ ID NO:2) derived
from the coding sequence of SEQ ID NO:1 shown in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] I. Definitions
[0031] The terms "PRO polypeptide" and "PRO" as used herein and
when immediately followed by a numerical designation refer to
various polypeptides, wherein the complete designation (i.e.,
PRO/number) refers to specific polypeptide sequences as described
herein. The terms "PRO/number polypeptide" and "PRO/number" wherein
the term "number" is provided as an actual numerical designation as
used herein encompass native sequence polypeptides and polypeptide
variants (which are further defined herein). The PRO polypeptides
described herein may be isolated from a variety of sources, such as
from human tissue types or from another source, or prepared by
recombinant or synthetic methods. The term "PRO polypeptide" refers
to each individual PRO/number polypeptide disclosed herein. All
disclosures in this specification which refer to the "PRO
polypeptide" refer to each of the polypeptides individually as well
as jointly. For example, descriptions of the preparation of,
purification of, derivation of, formation of antibodies to or
against, administration of, compositions containing, treatment of a
disease with, etc., pertain to each polypeptide of the invention
individually. The term "PRO polypeptide" also includes variants of
the PRO/number polypeptides disclosed herein.
[0032] A "native sequence PRO polypeptide" comprises a polypeptide
having the same amino acid sequence as the corresponding PRO
polypeptide derived from nature. Such native sequence PRO
polypeptides can be isolated from nature or can be produced by
recombinant or synthetic means. The term "native sequence PRO
polypeptide" specifically encompasses naturally-occurring truncated
or secreted forms of the specific PRO polypeptide (e.g., an
extracellular domain sequence), naturally-occurring variant forms
(e.g. alternatively spliced forms) and naturally-occurring allelic
variants of the polypeptide. In various embodiments of the
invention, the native sequence PRO polypeptides disclosed herein
are mature or full-length native sequence polypeptides comprising
the full-length amino acids sequences shown in the accompanying
figures. Start and stop codons are shown in bold font and
underlined in the figures. However, while the PRO polypeptide
disclosed in the accompanying figures are shown to begin with
methionine residues designated herein as amino acid position 1 in
the figures, it is conceivable and possible that other methionine
residues located either upstream or downstream from the amino acid
position 1 in the figures may be employed as the starting amino
acid residue for the PRO polypeptides.
[0033] The PRO polypeptide "extracellular domain" or "ECD" refers
to a form of the PRO polypeptide which is essentially free of the
transmembrane and cytoplasmic domains. Ordinarily, a PRO
polypeptide ECD will have less than 1% of such transmembrane and/or
cytoplasmic domains and preferably, will have less than 0.5% of
such domains. It will be understood that any transmembrane domains
identified for the PRO polypeptides of the present invention are
identified pursuant to criteria routinely employed in the art for
identifying that type of hydrophobic domain. The exact boundaries
of a transmembrane domain may vary but most likely by no more than
about 5 amino acids at either end of the domain as initially
identified herein. Optionally, therefore, an extracellular domain
of a PRO polypeptide may contain from about 5 or fewer amino acids
on either side of the transmembrane domain/extracellular domain
boundary as identified in the Examples or specification and such
polypeptides, with or without the associated signal peptide, and
nucleic acid encoding them, are comtemplated by the present
invention.
[0034] The approximate location of the "signal peptides" of the
various PRO polypeptides disclosed herein are shown in the present
specification and/or the accompanying figures. It is noted,
however, that the C-terminal boundary of a signal peptide may vary,
but most likely by no more than about 5 amino acids on either side
of the signal peptide C-terminal boundary as initially identified
herein, wherein the C-terminal boundary of the signal peptide may
be identified pursuant to criteria routinely employed in the art
for identifying that type of amino acid sequence element (e.g.,
Nielsen et al., Prot. Eng. 10:1-6 (1997) and von Heinje et al.,
Nucl. Acids. Res. 14:4683-4690 (1986)). Moreover, it is also
recognized that, in some cases, cleavage of a signal sequence from
a secreted polypeptide is not entirely uniform, resulting in more
than one secreted species. These mature polypeptides, where the
signal peptide is cleaved within no more than about 5 amino acids
on either side of the C-terminal boundary of the signal peptide as
identified herein, and the polynucleotides encoding them, are
contemplated by the present invention.
[0035] "PRO polypeptide variant" means an active PRO polypeptide as
defined above or below having at least about 80% amino acid
sequence identity with a full-length native sequence PRO
polypeptide sequence as disclosed herein, a PRO polypeptide
sequence lacking the signal peptide as disclosed herein, an
extracellular domain of a PRO polypeptide, with or without the
signal peptide, as disclosed herein or any other fragment of a
full-length PRO polypeptide sequence as disclosed herein. Such PRO
polypeptide variants include, for instance, PRO polypeptides
wherein one or more amino acid residues are added, or deleted, at
the N- or C-terminus of the full-length native amino acid sequence.
Ordinarily, a PRO polypeptide variant will have at least about 80%
amino acid sequence identity, alternatively at least about 81%
amino acid sequence identity, alternatively at least about 82%
amino acid sequence identity, alternatively at least about 83%
amino acid sequence identity, alternatively at least about 84%
amino acid sequence identity, alternatively at least about 85%
amino acid sequence identity, alternatively at least about 86%
amino acid sequence identity, alternatively at least about 87%
amino acid sequence identity, alternatively at least about 88%
amino acid sequence identity, alternatively at least about 89%
amino acid sequence identity, alternatively at least about 90%
amino acid sequence identity, alternatively at least about 91%
amino acid sequence identity, alternatively at least about 92%
amino acid sequence identity, alternatively at least about 93%
amino acid sequence identity, alternatively at least about 94%
amino acid sequence identity, alternatively at least about 95%
amino acid sequence identity, alternatively at least about 96%
amino acid sequence identity, alternatively at least about 97%
amino acid sequence identity, alternatively at least about 98%
amino acid sequence identity and alternatively at least about 99%
amino acid sequence identity to a full-length native sequence PRO
polypeptide sequence as disclosed herein, a PRO polypeptide
sequence lacking the signal peptide as disclosed herein, an
extracellular domain of a PRO polypeptide, with or without the
signal peptide, as disclosed herein or any other specifically
defined fragment of a full-length PRO polypeptide sequence as
disclosed herein. Ordinarily, PRO variant polypeptides are at least
about 10 amino acids in length, alternatively at least about 20
amino acids in length, alternatively at least about 30 amino acids
in length, alternatively at least about 40 amino acids in length,
alternatively at least about 50 amino acids in length,
alternatively at least about 60 amino acids in length,
alternatively at least about 70 amino acids in length,
alternatively at least about 80 amino acids in length,
alternatively at least about 90 amino acids in length,
alternatively at least about 100 amino acids in length,
alternatively at least about 150 amino acids in length,
alternatively at least about 200 amino acids in length,
alternatively at least about 300 amino acids in length, or
more.
[0036] "Percent (%) amino acid sequence identity" with respect to
the PRO polypeptide sequences identified herein is defined as the
percentage of amino acid residues in a candidate sequence that are
identical with the amino acid residues in the specific PRO
polypeptide sequence, after aligning the sequences and introducing
gaps, if necessary, to achieve the maximum percent sequence
identity, and not considering any conservative substitutions as
part of the sequence identity. Alignment for purposes of
determining percent amino acid sequence identity can be achieved in
various ways that are within the skill in the art, for instance,
using publicly available computer software such as BLAST, BLAST-2,
ALIGN or Megalign (DNASTAR) software. Those skilled in the art can
determine appropriate parameters for measuring alignment, including
any algorithms needed to achieve maximal alignment over the full
length of the sequences being compared. For purposes herein,
however, % amino acid sequence identity values are generated using
the sequence comparison computer program ALIGN-2, wherein the
complete source code for the ALIGN-2 program is provided in Table 1
(below) and as disclosed in at least U.S. application Ser. No.
10/052,586. The ALIGN-2 sequence comparison computer program was
authored by Genentech, Inc. and the source code shown in Table 1
(below) has been filed with user documentation in the U.S.
Copyright Office, Washington D.C., 20559, where it is registered
under U.S. Copyright Registration No. TXU510087. The ALIGN-2
program is publicly available through Genentech, Inc., South San
Francisco, Calif. or may be compiled from the source code provided
in Table 1 (below). The ALIGN-2 program should be compiled for use
on a UNIX operating system, preferably digital UNIX V4.0D. All
sequence comparison parameters are set by the ALIGN-2 program and
do not vary.
[0037] In situations where ALIGN-2 is employed for amino acid
sequence comparisons, the % amino acid sequence identity of a given
amino acid sequence A to, with, or against a given amino acid
sequence B (which can alternatively be phrased as a given amino
acid sequence A that has or comprises a certain % amino acid
sequence identity to, with, or against a given amino acid sequence
B) is calculated as follows:
100 times the fraction X/Y
[0038] where X is the number of amino acid residues scored as
identical matches by the sequence alignment program ALIGN-2 in that
program's alignment of A and B, and where Y is the total number of
amino acid residues in B. It will be appreciated that where the
length of amino acid sequence A is not equal to the length of amino
acid sequence B, the % amino acid sequence identity of A to B will
not equal the % amino acid sequence identity of B to A. As examples
of % amino acid sequence identity calculations using this method,
Tables 2 and 3 demonstrate how to calculate the % amino acid
sequence identity of the amino acid sequence designated "Comparison
Protein" to the amino acid sequence designated "PRO", wherein "PRO"
represents the amino acid sequence of a hypothetical PRO
polypeptide of interest, "Comparison Protein" represents the amino
acid sequence of a polypeptide against which the "PRO" polypeptide
of interest is being compared, and "X, "Y" and "Z" each represent
different hypothetical amino acid residues.
[0039] Unless specifically stated otherwise, all % amino acid
sequence identity values used herein are obtained as described in
the immediately preceding paragraph using the ALIGN-2 computer
program. However, % amino acid sequence identity values may also be
obtained as described below by using the WU-BLAST-2 computer
program (Altschul et al., Methods in Enzymology 266:460-480
(1996)). Most of the WU-BLAST-2 search parameters are set to the
default values. Those not set to default values, i.e., the
adjustable parameters, are set with the following values: overlap
span=1, overlap fraction=0.125, word threshold (T)=11, and scoring
matrix=BLOSUM62. When WU-BLAST-2 is employed, a % amino acid
sequence identity value is determined by dividing (a) the number of
matching identical amino acid residues between the amino acid
sequence of the PRO polypeptide of interest having a sequence
derived from the native PRO polypeptide and the comparison amino
acid sequence of interest (i.e., the sequence against which the PRO
polypeptide of interest is being compared which may be a PRO
variant polypeptide) as determined by WU-BLAST-2 by (b) the total
number of amino acid residues of the PRO polypeptide of interest.
For example, in the statement "a polypeptide comprising an the
amino acid sequence A which has or having at least 80% amino acid
sequence identity to the amino acid sequence B", the amino acid
sequence A is the comparison amino acid sequence of interest and
the amino acid sequence B is the amino acid sequence of the PRO
polypeptide of interest.
[0040] Percent amino acid sequence identity may also be determined
using the sequence comparison program NCBI-BLAST2 (Altschul et al.,
Nucleic Acids Res. 25:3389-3402 (1997)). The NCBI-BLAST2 sequence
comparison program may be obtained from the National Institute of
Health, Bethesda, Md. NCBI-BLAST2 uses several search parameters,
wherein all of those search parameters are set to default values
including, for example, unmask=yes, strand=all, expected
occurrences=10, minimum low complexity length=15/5, multi-pass
e-value=0.01, constant for multi-pass=25, dropoff for final gapped
alignment=25 and scoring matrix=BLOSUM62.
[0041] In situations where NCBI-BLAST2 is employed for amino acid
sequence comparisons, the % amino acid sequence identity of a given
amino acid sequence A to, with, or against a given amino acid
sequence B (which can alternatively be phrased as a given amino
acid sequence A that has or comprises a certain % amino acid
sequence identity to, with, or against a given amino acid sequence
B) is calculated as follows:
100 times the fraction X/Y
[0042] where X is the number of amino acid residues scored as
identical matches by the sequence alignment program NCBI-BLAST2 in
that program's alignment of A and B, and where Y is the total
number of amino acid residues in B. It will be appreciated that
where the length of amino acid sequence A is not equal to the
length of amino acid sequence B, the % amino acid sequence identity
of A to B will not equal the % amino acid sequence identity of B to
A.
[0043] "PRO variant polynucleotide" or "PRO variant nucleic acid
sequence" means a nucleic acid molecule which encodes an active PRO
polypeptide as defined below and which has at least about 80%
nucleic acid sequence identity with a nucleotide acid sequence
encoding a full-length native sequence PRO polypeptide sequence as
disclosed herein, a full-length native sequence PRO polypeptide
sequence lacking the signal peptide as disclosed herein, an
extracellular domain of a PRO polypeptide, with or without the
signal peptide, as disclosed herein or any other fragment of a
full-length PRO polypeptide sequence as disclosed herein.
Ordinarily, a PRO variant polynucleotide will have at least about
80% nucleic acid sequence identity, alternatively at least about
81% nucleic acid sequence identity, alternatively at least about
82% nucleic acid sequence identity, alternatively at least about
83% nucleic acid sequence identity, alternatively at least about
84% nucleic acid sequence identity, alternatively at least about
85% nucleic acid sequence identity, alternatively at least about
86% nucleic acid sequence identity, alternatively at least about
87% nucleic acid sequence identity, alternatively at least about
88% nucleic acid sequence identity, alternatively at least about
89% nucleic acid sequence identity, alternatively at least about
90% nucleic acid sequence identity, alternatively at least about
91% nucleic acid sequence identity, alternatively at least about
92% nucleic acid sequence identity, alternatively at least about
93% nucleic acid sequence identity, alternatively at least about
94% nucleic acid sequence identity, alternatively at least about
95% nucleic acid sequence identity, alternatively at least about
96% nucleic acid sequence identity, alternatively at least about
97% nucleic acid sequence identity, alternatively at least about
98% nucleic acid sequence identity and alternatively at least about
99% nucleic acid sequence identity with a nucleic acid sequence
encoding a full-length native sequence PRO polypeptide sequence as
disclosed herein, a full-length native sequence PRO polypeptide
sequence lacking the signal peptide as disclosed herein, an
extracellular domain of a PRO polypeptide, with or without the
signal sequence, as disclosed herein or any other fragment of a
full-length PRO polypeptide sequence as disclosed herein. Variants
do not encompass the native nucleotide sequence.
[0044] Ordinarily, PRO variant polynucleotides are at least about
30 nucleotides in length, alternatively at least about 60
nucleotides in length, alternatively at least about 90 nucleotides
in length, alternatively at least about 120 nucleotides in length,
alternatively at least about 150 nucleotides in length,
alternatively at least about 180 nucleotides in length,
alternatively at least about 210 nucleotides in length,
alternatively at least about 240 nucleotides in length,
alternatively at least about 270 nucleotides in length,
alternatively at least about 300 nucleotides in length,
alternatively at least about 450 nucleotides in length,
alternatively at least about 600 nucleotides in length,
alternatively at least about 900 nucleotides in length, or
more.
[0045] "Percent (%) nucleic acid sequence identity" with respect to
PRO-encoding nucleic acid sequences identified herein is defined as
the percentage of nucleotides in a candidate sequence that are
identical with the nucleotides in the PRO nucleic acid sequence of
interest, after aligning the sequences and introducing gaps, if
necessary, to achieve the maximum percent sequence identity.
Alignment for purposes of determining percent nucleic acid sequence
identity can be achieved in various ways that are within the skill
in the art, for instance, using publicly available computer
software such as BLAST, BLAST-2, ALIGN or Megalign (DNASTAR)
software. For purposes herein, however, % nucleic acid sequence
identity values are generated using the sequence comparison
computer program ALIGN-2, wherein the complete source code for the
ALIGN-2 program is provided in Table 1 (below). The ALIGN-2
sequence comparison computer program was authored by Genentech,
Inc. and the source code shown in Table 1 (below) has been filed
with user documentation in the U.S. Copyright Office, Washington
D.C., 20559, where it is registered under U.S. Copyright
Registration No. TXU510087. The ALIGN-2 program is publicly
available through Genentech, Inc., South San Francisco, Calif. or
may be compiled from the source code provided in Table 1 (below).
The ALIGN-2 program should be compiled for use on a UNIX operating
system, preferably digital UNIX V4.0D. All sequence comparison
parameters are set by the ALIGN-2 program and do not vary.
[0046] In situations where ALIGN-2 is employed for nucleic acid
sequence comparisons, the % nucleic acid sequence identity of a
given nucleic acid sequence C to, with, or against a given nucleic
acid sequence D (which can alternatively be phrased as a given
nucleic acid sequence C that has or comprises a certain % nucleic
acid sequence identity to, with, or against a given nucleic acid
sequence D) is calculated as follows:
100 times the fraction W/Z
[0047] where W is the number of nucleotides scored as identical
matches by the sequence alignment program ALIGN-2 in that program's
alignment of C and D, and where Z is the total number of
nucleotides in D. It will be appreciated that where the length of
nucleic acid sequence C is not equal to the length of nucleic acid
sequence D, the % nucleic acid sequence identity of C to D will not
equal the % nucleic acid sequence identity of D to C. As examples
of % nucleic acid sequence identity calculations, Tables 4 and 5,
demonstrate how to calculate the % nucleic acid sequence identity
of the nucleic acid sequence designated "Comparison DNA" to the
nucleic acid sequence designated "PRO-DNA", wherein "PRO-DNA"
represents a hypothetical PRO-encoding nucleic acid sequence of
interest, "Comparison DNA" represents the nucleotide sequence of a
nucleic acid molecule against which the "PRO-DNA" nucleic acid
molecule of interest is being compared, and "N", "L" and "V" each
represent different hypothetical nucleotides.
[0048] Unless specifically stated otherwise, all % nucleic acid
sequence identity values used herein are obtained as described in
the immediately preceding paragraph using the ALIGN-2 computer
program. However, % nucleic acid sequence identity values may also
be obtained as described below by using the WU-BLAST-2 computer
program (Altschul et al., Methods in Enzymology 266:460-480
(1996)). Most of the WU-BLAST-2 search parameters are set to the
default values. Those not set to default values, i.e., the
adjustable parameters, are set with the following values: overlap
span=1, overlap fraction=0.125, word threshold (T)=11, and scoring
matrix=BLOSUM62. When WU-BLAST-2 is employed, a % nucleic acid
sequence identity value is determined by dividing (a) the number of
matching identical nucleotides between the nucleic acid sequence of
the PRO polypeptide-encoding nucleic acid molecule of interest
having a sequence derived from the native sequence PRO
polypeptide-encoding nucleic acid and the comparison nucleic acid
molecule of interest (i.e., the sequence against which the PRO
polypeptide-encoding nucleic acid molecule of interest is being
compared which may be a variant PRO polynucleotide) as determined
by WU-BLAST-2 by (b) the total number of nucleotides of the PRO
polypeptide-encoding nucleic acid molecule of interest. For
example, in the statement "an isolated nucleic acid molecule
comprising a nucleic acid sequence A which has or having at least
80% nucleic acid sequence identity to the nucleic acid sequence B",
the nucleic acid sequence A is the comparison nucleic acid molecule
of interest and the nucleic acid sequence B is the nucleic acid
sequence of the PRO polypeptide-encoding nucleic acid molecule of
interest.
[0049] Percent nucleic acid sequence identity may also be
determined using the sequence comparison program NCBI-BLAST2
(Altschul et al., Nucleic Acids Res. 25:3389-3402 (1997)). The
NCBI-BLAST2 sequence comparison program may be obtained from the
National Institute of Health, Bethesda, Md. NCBI-BLAST2 uses
several search parameters, wherein all of those search parameters
are set to default values including, for example, unmask=yes,
strand=all, expected occurrences=10, minimum low complexity
length=15/5, multi-pass e-value=0.01, constant for multi-pass=25,
dropoff for final gapped alignment=25 and scoring
matrix=BLOSUM62.
[0050] In situations where NCBI-BLAST2 is employed for sequence
comparisons, the % nucleic acid sequence identity of a given
nucleic acid sequence C to, with, or against a given nucleic acid
sequence D (which can alternatively be phrased as a given nucleic
acid sequence C that has or comprises a certain % nucleic acid
sequence identity to, with, or against a given nucleic acid
sequence D) is calculated as follows:
100 times the fraction W/Z
[0051] where W is the number of nucleotides scored as identical
matches by the sequence alignment program NCBI-BLAST2 in that
program's alignment of C and D, and where Z is the total number of
nucleotides in D. It will be appreciated that where the length of
nucleic acid sequence C is not equal to the length of nucleic acid
sequence D, the % nucleic acid sequence identity of C to D will not
equal the % nucleic acid sequence identity of D to C.
[0052] In other embodiments, PRO variant polynucleotides are
nucleic acid molecules that encode an active PRO polypeptide and
which are capable of hybridizing, preferably under stringent
hybridization and wash conditions, to nucleotide sequences encoding
a full-length PRO polypeptide as disclosed herein. PRO variant
polypeptides may be those that are encoded by a PRO variant
polynucleotide.
[0053] "Isolated," when used to describe the various polypeptides
disclosed herein, means polypeptide that has been identified and
separated and/or recovered from a component of its natural
environment. Contaminant components of its natural environment are
materials that would typically interfere with diagnostic or
therapeutic uses for the polypeptide, and may include enzymes,
hormones, and other proteinaceous or non-proteinaceous solutes. In
preferred embodiments, the polypeptide will be purified (1) to a
degree sufficient to obtain at least 15 residues of N-terminal or
internal amino acid sequence by use of a spinning cup sequenator,
or (2) to homogeneity by SDS-PAGE under non-reducing or reducing
conditions using Coomassie blue or, preferably, silver stain.
Isolated polypeptide includes polypeptide in situ within
recombinant cells, since at least one component of the PRO
polypeptide natural environment will not be present. Ordinarily,
however, isolated polypeptide will be prepared by at least one
purification step.
[0054] An "isolated" PRO polypeptide-encoding nucleic acid or other
polypeptide-encoding nucleic acid is a nucleic acid molecule that
is identified and separated from at least one contaminant nucleic
acid molecule with which it is ordinarily associated in the natural
source of the polypeptide-encoding nucleic acid. An isolated
polypeptide-encoding nucleic acid molecule is other than in the
form or setting in which it is found in nature. Isolated
polypeptide-encoding nucleic acid molecules therefore are
distinguished from the specific polypeptide-encoding nucleic acid
molecule as it exists in natural cells. However, an isolated
polypeptide-encoding nucleic acid molecule includes
polypeptide-encoding nucleic acid molecules contained in cells that
ordinarily express the polypeptide where, for example, the nucleic
acid molecule is in a chromosomal location different from that of
natural cells.
[0055] The term "control sequences" refers to DNA sequences
necessary for the expression of an operably linked coding sequence
in a particular host organism. The control sequences that are
suitable for prokaryotes, for example, include a promoter,
optionally an operator sequence, and a ribosome binding site.
Eukaryotic cells are known to utilize promoters, polyadenylation
signals, and enhancers.
[0056] Nucleic acid is "operably linked" when it is placed into a
functional relationship with another nucleic acid sequence. For
example, DNA for a presequence or secretory leader is operably
linked to DNA for a polypeptide if it is expressed as a preprotein
that participates in the secretion of the polypeptide; a promoter
or enhancer is operably linked to a coding sequence if it affects
the transcription of the sequence; or a ribosome binding site is
operably linked to a coding sequence if it is positioned so as to
facilitate translation. Generally, "operably linked" means that the
DNA sequences being linked are contiguous, and, in the case of a
secretory leader, contiguous and in reading phase. However,
enhancers do not have to be contiguous. Linking is accomplished by
ligation at convenient restriction sites. If such sites do not
exist, the synthetic oligonucleotide adaptors or linkers are used
in accordance with conventional practice.
[0057] The term "antibody" is used in the broadest sense and
specifically covers, for example, single anti-PRO monoclonal
antibodies (including agonist, antagonist, and neutralizing
antibodies), anti-PRO antibody compositions with polyepitopic
specificity, single chain anti-PRO antibodies, and fragments of
anti-PRO antibodies (see below). The term "monoclonal antibody" as
used herein refers to an antibody obtained from a population of
substantially homogeneous antibodies, i.e., the individual
antibodies comprising the population are identical except for
possible naturally-occurring mutations that may be present in minor
amounts.
[0058] "Stringency" of hybridization reactions is readily
determinable by one of ordinary skill in the art, and generally is
an empirical calculation dependent upon probe length, washing
temperature, and salt concentration. In general, longer probes
require higher temperatures for proper annealing, while shorter
probes need lower temperatures. Hybridization generally depends on
the ability of denatured DNA to reanneal when complementary strands
are present in an environment below their melting temperature. The
higher the degree of desired homology between the probe and
hybridizable sequence, the higher the relative temperature which
can be used. As a result, it follows that higher relative
temperatures would tend to make the reaction conditions more
stringent, while lower temperatures less so. For additional details
and explanation of stringency of hybridization reactions, see
Ausubel et al., Current Protocols in Molecular Biology, Wiley
Interscience Publishers, (1995).
[0059] "Stringent conditions" or "high stringency conditions", as
defined herein, may be identified by those that: (1) employ low
ionic strength and high temperature for washing, for example 0.015
M sodium chloride/0.0015 M sodium citrate/0.1% sodium dodecyl
sulfate at 50.degree. C.; (2) employ during hybridization a
denaturing agent, such as formamide, for example, 50% (v/v)
formamide with 0.1% bovine serum albumin/0.1% Ficoll/0.1%
polyvinylpyrrolidone/50 mM sodium phosphate buffer at pH 6.5 with
750 mM sodium chloride, 75 mM sodium citrate at 42.degree. C.; or
(3) employ 50% formamide, 5.times.SSC (0.75 M NaCl, 0.075 M sodium
citrate), 50 mM sodium phosphate (pH 6.8), 0.1% sodium
pyrophosphate, 5.times. Denhardt's solution, sonicated salmon sperm
DNA (50 .mu.g/ml), 0.1% SDS, and 10% dextran sulfate at 42.degree.
C., with washes at 42.degree. C. in 0.2.times.SSC (sodium
chloride/sodium citrate) and 50% formamide at 55.degree. C.,
followed by a high-stringency wash consisting of 0.1.times.SSC
containing EDTA at 55.degree. C.
[0060] "Moderately stringent conditions" may be identified as
described by Sambrook et al., Molecular Cloning: A Laboratory
Manual, New York: Cold Spring Harbor Press, 1989, and include the
use of washing solution and hybridization conditions (e.g.,
temperature, ionic strength and % SDS) less stringent that those
described above. An example of moderately stringent conditions is
overnight incubation at 37.degree. C. in a solution comprising: 20%
formamide, 5.times.SSC (150 mM NaCl, 15 mM trisodium citrate), 50
mM sodium phosphate (pH 7.6), 5.times. Denhardt's solution, 10%
dextran sulfate, and 20 mg/ml denatured sheared salmon sperm DNA,
followed by washing the filters in 1.times.SSC at about
37-50.degree. C. The skilled artisan will recognize how to adjust
the temperature, ionic strength, etc. as necessary to accommodate
factors such as probe length and the like.
[0061] The term "epitope tagged" when used herein refers to a
chimeric polypeptide comprising a PRO polypeptide fused to a "tag
polypeptide". The tag polypeptide has enough residues to provide an
epitope against which an antibody can be made, yet is short enough
such that it does not interfere with activity of the polypeptide to
which it is fused. The tag polypeptide preferably also is fairly
unique so that the antibody does not substantially cross-react with
other epitopes. Suitable tag polypeptides generally have at least
six amino acid residues and usually between about 8 and 50 amino
acid residues (preferably, between about 10 and 20 amino acid
residues).
[0062] As used herein, the term "immunoadhesin" designates
antibody-like molecules which combine the binding specificity of a
heterologous protein (an "adhesin") with the effector functions of
immunoglobulin constant domains. Structurally, the immunoadhesins
comprise a fusion of an amino acid sequence with the desired
binding specificity which is other than the antigen recognition and
binding site of an antibody (i.e., is "heterologous"), and an
immunoglobulin constant domain sequence. The adhesin part of an
immunoadhesin molecule typically is a contiguous amino acid
sequence comprising at least the binding site of a receptor or a
ligand. The immunoglobulin constant domain sequence in the
immunoadhesin may be obtained from any immunoglobulin, such as
IgG-1, IgG-2, IgG-3, or IgG-4 subtypes, IgA (including IgA-1 and
IgA-2), IgE, IgD or IgM.
[0063] "Active" or "activity" for the purposes herein refers to
form(s) of a PRO polypeptide which retain a biological and/or an
immunological activity of native or naturally-occurring PRO,
wherein "biological" activity refers to a biological function
(either inhibitory or stimulatory) caused by a native or
naturally-occurring PRO other than the ability to induce the
production of an antibody against an antigenic epitope possessed by
a native or naturally-occurring PRO and an "immunological" activity
refers to the ability to induce the production of an antibody
against an antigenic epitope possessed by a native or
naturally-occurring PRO.
[0064] The term "antagonist" is used in the broadest sense, and
includes any molecule that partially or fully blocks, inhibits, or
neutralizes a biological activity of a native PRO polypeptide
disclosed herein. In a similar manner, the term "agonist" is used
in the broadest sense and includes any molecule that mimics a
biological activity of a native PRO polypeptide disclosed herein.
Suitable agonist or antagonist molecules specifically include
agonist or antagonist antibodies or antibody fragments, fragments
or amino acid sequence variants of native PRO polypeptides,
peptides, antisense oligonucleotides, small organic molecules, etc.
Methods for identifying agonists or antagonists of a PRO
polypeptide may comprise contacting a PRO polypeptide with a
candidate agonist or antagonist molecule and measuring a detectable
change in one or more biological activities normally associated
with the PRO polypeptide.
[0065] "Treatment" refers to both therapeutic treatment and
prophylactic or preventative measures, wherein the object is to
prevent or slow down (lessen) the targeted pathologic condition or
disorder. Those in need of treatment include those already with the
disorder as well as those prone to have the disorder or those in
whom the disorder is to be prevented.
[0066] "Chronic" administration refers to administration of the
agent(s) in a continuous mode as opposed to an acute mode, so as to
maintain the initial therapeutic effect (activity) for an extended
period of time. "Intermittent" administration is treatment that is
not consecutively done without interruption, but rather is cyclic
in nature.
[0067] "Mammal" for purposes of treatment refers to any animal
classified as a mammal, including humans, domestic and farm
animals, and zoo, sports, or pet animals, such as dogs, cats,
cattle, horses, sheep, pigs, goats, rabbits, etc. Preferably, the
mammal is human.
[0068] Administration "in combination with" one or more further
therapeutic agents includes simultaneous (concurrent) and
consecutive administration in any order.
[0069] "Carriers" as used herein include pharmaceutically
acceptable carriers, excipients, or stabilizers which are nontoxic
to the cell or mammal being exposed thereto at the dosages and
concentrations employed. Often the physiologically acceptable
carrier is an aqueous pH buffered solution. Examples of
physiologically acceptable carriers include buffers such as
phosphate, citrate, and other organic acids; antioxidants including
ascorbic acid; low molecular weight (less than about 10 residues)
polypeptide; proteins, such as serum albumin, gelatin, or
immunoglobulins; hydrophilic polymers such as polyvinylpyrrolidone;
amino acids such as glycine, glutamine, asparagine, arginine or
lysine; monosaccharides, disaccharides, and other carbohydrates
including glucose, mannose, or dextrins; chelating agents such as
EDTA; sugar alcohols such as mannitol or sorbitol; salt-forming
counterions such as sodium; and/or nonionic surfactants such as
TWEEN.TM., polyethylene glycol (PEG), and PLURONICS.TM..
[0070] "Antibody fragments" comprise a portion of an intact
antibody, preferably the antigen binding or variable region of the
intact antibody. Examples of antibody fragments include Fab, Fab',
F(ab').sub.2, and Fv fragments; diabodies; linear antibodies
(Zapata et al., Protein Eng. 8(10): 1057-1062 [1995]); single-chain
antibody molecules; and multispecific antibodies formed from
antibody fragments.
[0071] Papain digestion of antibodies produces two identical
antigen-binding fragments, called "Fab" fragments, each with a
single antigen-binding site, and a residual "Fc" fragment, a
designation reflecting the ability to crystallize readily. Pepsin
treatment yields an F(ab').sub.2 fragment that has two
antigen-combining sites and is still capable of cross-linking
antigen.
[0072] "Fv" is the minimum antibody fragment which contains a
complete antigen-recognition and -binding site. This region
consists of a dimer of one heavy- and one light-chain variable
domain in tight, non-covalent association. It is in this
configuration that the three CDRs of each variable domain interact
to define an antigen-binding site on the surface of the
V.sub.H-V.sub.L dimer. Collectively, the six CDRs confer
antigen-binding specificity to the antibody. However, even a single
variable domain (or half of an Fv comprising only three CDRs
specific for an antigen) has the ability to recognize and bind
antigen, although at a lower affinity than the entire binding
site.
[0073] The Fab fragment also contains the constant domain of the
light chain and the first constant domain (CH1) of the heavy chain.
Fab fragments differ from Fab' fragments by the addition of a few
residues at the carboxy terminus of the heavy chain CH1 domain
including one or more cysteines from the antibody hinge region.
Fab'-SH is the designation herein for Fab' in which the cysteine
residue(s) of the constant domains bear a free thiol group.
F(ab').sub.2 antibody fragments originally were produced as pairs
of Fab' fragments which have hinge cysteines between them. Other
chemical couplings of antibody fragments are also known.
[0074] The "light chains" of antibodies (immunoglobulins) from any
vertebrate species can be assigned to one of two clearly distinct
types, called kappa and lambda, based on the amino acid sequences
of their constant domains.
[0075] Depending on the amino acid sequence of the constant domain
of their heavy chains, immunoglobulins can be assigned to different
classes. There are five major classes of immunoglobulins: IgA, IgD,
IgE, IgG, and IgM, and several of these may be further divided into
subclasses (isotypes), e.g., IgG1, IgG2, IgG3, IgG4, IgA, and
IgA2.
[0076] "Single-chain Fv" or "sFv" antibody fragments comprise the
V.sub.H and V.sub.L domains of antibody, wherein these domains are
present in a single polypeptide chain. Preferably, the Fv
polypeptide further comprises a polypeptide linker between the
V.sub.H and V.sub.L domains which enables the sFv to form the
desired structure for antigen binding. For a review of sFv, see
Pluckthun in The Pharmacology of Monoclonal Antibodies, vol. 113,
Rosenburg and Moore eds., Springer-Verlag, New York, pp. 269-315
(1994).
[0077] The term "diabodies" refers to small antibody fragments with
two antigen-binding sites, which fragments comprise a heavy-chain
variable domain (V.sub.H) connected to a light-chain variable
domain (V.sub.L) in the same polypeptide chain (V.sub.H-V.sub.L).
By using a linker that is too short to allow pairing between the
two domains on the same chain, the domains are forced to pair with
the complementary domains of another chain and create two
antigen-binding sites. Diabodies are described more fully in, for
example, EP 404,097; WO 93/11161; and Hollinger et al., Proc. Natl.
Acad. Sci. USA, 90:6444-6448 (1993).
[0078] An "isolated" antibody is one which has been identified and
separated and/or recovered from a component of its natural
environment. Contaminant components of its natural environment are
materials which would interfere with diagnostic or therapeutic uses
for the antibody, and may include enzymes, hormones, and other
proteinaceous or nonproteinaceous solutes. In preferred
embodiments, the antibody will be purified (1) to greater than 95%
by weight of antibody as determined by the Lowry method, and most
preferably more than 99% by weight, (2) to a degree sufficient to
obtain at least 15 residues of N-terminal or internal amino acid
sequence by use of a spinning cup sequenator, or (3) to homogeneity
by SDS-PAGE under reducing or nonreducing conditions using
Coomassie blue or, preferably, silver stain. Isolated antibody
includes the antibody in situ within recombinant cells since at
least one component of the antibody's natural environment will not
be present. Ordinarily, however, isolated antibody will be prepared
by at least one purification step.
[0079] An antibody that "specifically binds to" or is "specific
for" a particular polypeptide or an epitope on a particular
polypeptide is one that binds to that particular polypeptide or
epitope on a particular polypeptide without substantially binding
to any other polypeptide or polypeptide epitope.
[0080] The word "label" when used herein refers to a detectable
compound or composition which is conjugated directly or indirectly
to the antibody so as to generate a "labeled" antibody. The label
may be detectable by itself (e.g. radioisotope labels or
fluorescent labels) or, in the case of an enzymatic label, may
catalyze chemical alteration of a substrate compound or composition
which is detectable.
[0081] By "solid phase" is meant a non-aqueous matrix to which the
antibody of the present invention can adhere. Examples of solid
phases encompassed herein include those formed partially or
entirely of glass (e.g., controlled pore glass), polysaccharides
(e.g., agarose), polyacrylamides, polystyrene, polyvinyl alcohol
and silicones. In certain embodiments, depending on the context,
the solid phase can comprise the well of an assay plate; in others
it is a purification column (e.g., an affinity chromatography
column). This term also includes a discontinuous solid phase of
discrete particles, such as those described in U.S. Pat. No.
4,275,149.
[0082] A "liposome" is a small vesicle composed of various types of
lipids, phospholipids and/or surfactant which is useful for
delivery of a drug (such as a PRO polypeptide or antibody thereto)
to a mammal. The components of the liposome are commonly arranged
in a bilayer formation, similar to the lipid arrangement of
biological membranes.
[0083] A "small molecule" is defined herein to have a molecular
weight below about 500 Daltons.
[0084] An "effective amount" of a polypeptide disclosed herein or
an agonist or antagonist thereof is an amount sufficient to carry
out a specifically stated purpose. An "effective amount" may be
determined empirically and in a routine manner, in relation to the
stated purpose.
1TABLE 2 PRO XXXXXXXXXXXXXXX (Length = 15 amino acids) Comparison
XXXXXYYYYYYY (Length = 12 amino acids) Protein % amino acid
sequence identity = (the number of identically matching amino acid
resides between the two polypeptide sequences as determined by
ALIGN-2) divided by (the total number of amino acid residues of the
PRO polypeptide) = 5 divided by 15 = 33.3%
[0085]
2TABLE 3 PRO XXXXXXXXXX (Length = 10 amino acids) Comparison
XXXXXYYYYYYZZYZ (Length = 15 amino acids) Protein % amino acid
sequence identity = (the number of identically matching amino acid
resides between the two polypeptide sequences as determined by
ALIGN-2) divided by (the total number of amino acid residues of the
PRO polypeptide) = 5 divided by 10 = 50%
[0086]
3TABLE 4 PRO-DNA NNNNNNNNNNNNNN (Length = 14 nucleotides)
Comparison NNNNNNLLLLLLLLLL (Length = 16 nucleotides) DNA % nucleic
acid sequence identity = (the number of identically matching
nucleotides between the two nucleic acid sequences as determined by
ALIGN-2) divided by (the total number of nucleotides of the PRO-DNA
nucleic acid sequence) = 6 divided by 14 = 42.9%
[0087]
4TABLE 5 PRO-DNA NNNNNNNNNNNN (Length = 12 nucleotides) Comparison
DNA NNNNLLLVV (Length = 9 nucleotides) % nucleic acid sequence
identity = (the number of identically matching nucleotides between
the two nucleic acid sequences as determined by ALIGN-2) divided by
(the total number of nucleotides of the PRO-DNA nucleic acid
sequence) = 4 divided by 12 = 33.3%
[0088] II. Compositions and Methods of the Invention
[0089] A. Full-Length PRO Polypeptides
[0090] The present invention provides newly identified and isolated
nucleotide sequences encoding polypeptides referred to in the
present application as PRO polypeptides. In particular, cDNAs
encoding various PRO polypeptides have been identified and
isolated, as disclosed in further detail in the Examples below. It
is noted that proteins produced in separate expression rounds may
be given different PRO numbers but the UNQ number is unique for any
given DNA and the encoded protein, and will not be changed.
However, for sake of simplicity, in the present specification the
protein encoded by the full length native nucleic acid molecules
disclosed herein as well as all further native homologues and
variants included in the foregoing definition of PRO, will be
referred to as "PRO/number", regardless of their origin or mode of
preparation.
[0091] As disclosed in the Examples below, various cDNA clones have
been deposited with the ATCC. The actual nucleotide sequences of
those clones can readily be determined by the skilled artisan by
sequencing of the deposited clone using routine methods in the art.
The predicted amino acid sequence can be determined from the
nucleotide sequence using routine skill. For the PRO polypeptides
and encoding nucleic acids described herein, Applicants have
identified what is believed to be the reading frame best
identifiable with the sequence information available at the
time.
[0092] B. PRO Polypeptide Variants
[0093] In addition to the full-length native sequence PRO
polypeptides described herein, it is contemplated that PRO variants
can be prepared. PRO variants can be prepared by introducing
appropriate nucleotide changes into the PRO DNA, and/or by
synthesis of the desired PRO polypeptide. Those skilled in the art
will appreciate that amino acid changes may alter
post-translational processes of the PRO, such as changing the
number or position of glycosylation sites or altering the membrane
anchoring characteristics.
[0094] Variations in the native full-length sequence PRO or in
various domains of the PRO described herein, can be made, for
example, using any of the techniques and guidelines for
conservative and non-conservative mutations set forth, for
instance, in U.S. Pat. No. 5,364,934. Variations may be a
substitution, deletion or insertion of one or more codons encoding
the PRO that results in a change in the amino acid sequence of the
PRO as compared with the native sequence PRO. Optionally the
variation is by substitution of at least one amino acid with any
other amino acid in one or more of the domains of the PRO. Guidance
in determining which amino acid residue may be inserted,
substituted or deleted without adversely affecting the desired
activity may be found by comparing the sequence of the PRO with
that of homologous known protein molecules and minimizing the
number of amino acid sequence changes made in regions of high
homology. Amino acid substitutions can be the result of replacing
one amino acid with another amino acid having similar structural
and/or chemical properties, such as the replacement of a leucine
with a serine, i.e., conservative amino acid replacements.
Insertions or deletions may optionally be in the range of about 1
to 5 amino acids. The variation allowed may be determined by
systematically making insertions, deletions or substitutions of
amino acids in the sequence and testing the resulting variants for
activity exhibited by the full-length or mature native
sequence.
[0095] PRO polypeptide fragments are provided herein. Such
fragments may be truncated at the N-terminus or C-terminus, or may
lack internal residues, for example, when compared with a full
length native protein. Certain fragments lack amino acid residues
that are not essential for a desired biological activity of the PRO
polypeptide.
[0096] PRO fragments may be prepared by any of a number of
conventional techniques. Desired peptide fragments may be
chemically synthesized. An alternative approach involves generating
PRO fragments by enzymatic digestion, e.g., by treating the protein
with an enzyme known to cleave proteins at sites defined by
particular amino acid residues, or by digesting the DNA with
suitable restriction enzymes and isolating the desired fragment.
Yet another suitable technique involves isolating and amplifying a
DNA fragment encoding a desired polypeptide fragment, by polymerase
chain reaction (PCR). Oligonucleotides that define the desired
termini of the DNA fragment are employed at the 5' and 3' primers
in the PCR. Preferably, PRO polypeptide fragments share at least
one biological and/or immunological activity with the native PRO
polypeptide disclosed herein.
[0097] In particular embodiments, conservative substitutions of
interest are shown in Table 6 under the heading of preferred
substitutions. If such substitutions result in a change in
biological activity, then more substantial changes, denominated
exemplary substitutions in Table 6, or as further described below
in reference to amino acid classes, are introduced and the products
screened.
5 TABLE 6 Original Exemplary Preferred Residue Substitutions
Substitutions Ala (A) val; leu; ile val Arg (R) lys; gln; asn lys
Asn (N) gln; his; lys; arg gln Asp (D) glu glu Cys (C) ser ser Gln
(Q) asn asn Glu (E) asp asp Gly (G) pro; ala ala His (H) asn; gln;
lys; arg arg Ile (I) leu; val; met; ala; phe; leu norleucine Leu
(L) norleucine; ile; val; ile met; ala; phe Lys (K) arg; gln; asn
arg Met (M) leu; phe; ile leu Phe (F) leu; val; ile; ala; tyr leu
Pro (P) ala ala Ser (S) thr thr Thr (T) ser ser Trp (W) tyr; phe
tyr Tyr (Y) trp; phe; thr; ser phe Val (V) ile; leu; met; phe; leu
ala; norleucine
[0098] Substantial modifications in function or immunological
identity of the PRO polypeptide are accomplished by selecting
substitutions that differ significantly in their effect on
maintaining (a) the structure of the polypeptide backbone in the
area of the substitution, for example, as a sheet or helical
conformation, (b) the charge or hydrophobicity of the molecule at
the target site, or (c) the bulk of the side chain. Naturally
occurring residues are divided into groups based on common
side-chain properties:
[0099] (1) hydrophobic: norleucine, met, ala, val, leu, ile;
[0100] (2) neutral hydrophilic: cys, ser, thr;
[0101] (3) acidic: asp, glu;
[0102] (4) basic: asn, gln, his, lys, arg;
[0103] (5) residues that influence chain orientation: gly, pro;
and
[0104] (6) aromatic: trp, tyr, phe.
[0105] Non-conservative substitutions will entail exchanging a
member of one of these classes for another class. Such substituted
residues also may be introduced into the conservative substitution
sites or, more preferably, into the remaining (non-conserved)
sites.
[0106] The variations can be made using methods known in the art
such as oligonucleotide-mediated (site-directed) mutagenesis,
alanine scanning, and PCR mutagenesis. Site-directed mutagenesis
[Carter et al., Nucl. Acids Res., 13:4331 (1986); Zoller et al.,
Nucl. Acids Res., 10:6487 (1987)], cassette mutagenesis [Wells et
al., Gene, 34:315 (1985)], restriction selection mutagenesis [Wells
et al., Philos. Trans. R. Soc. London SerA, 317:415 (1986)] or
other known techniques can be performed on the cloned DNA to
produce the PRO variant DNA.
[0107] Scanning amino acid analysis can also be employed to
identify one or more amino acids along a contiguous sequence. Among
the preferred scanning amino acids are relatively small, neutral
amino acids. Such amino acids include alanine, glycine, serine, and
cysteine. Alanine is typically a preferred scanning amino acid
among this group because it eliminates the side-chain beyond the
beta-carbon and is less likely to alter the main-chain conformation
of the variant [Cunningham and Wells, Science, 244: 1081-1085
(1989)]. Alanine is also typically preferred because it is the most
common amino acid. Further, it is frequently found in both buried
and exposed positions [Creighton, The Proteins, (W.H. Freeman &
Co., N.Y.); Chothia, J. Mol. Biol., 150:1 (1976)]. If alanine
substitution does not yield adequate amounts of variant, an
isoteric amino acid can be used.
[0108] C. Modifications of PRO
[0109] Covalent modifications of PRO are included within the scope
of this invention. One type of covalent modification includes
reacting targeted amino acid residues of a PRO polypeptide with an
organic derivatizing agent that is capable of reacting with
selected side chains or the N- or C-terminal residues of the PRO.
Derivatization with bifunctional agents is useful, for instance,
for crosslinking PRO to a water-insoluble support matrix or surface
for use in the method for purifying anti-PRO antibodies, and
vice-versa. Commonly used crosslinking agents include, e.g.,
1,1-bis(diazoacetyl)-2-phenylethane, glutaraldehyde,
N-hydroxysuccinimide esters, for example, esters with
4-azidosalicylic acid, homobifunctional imidoesters, including
disuccinimidyl esters such as
3,3'-dithiobis(succinimidylpropionate), bifunctional maleimides
such as bis-N-maleimido-1,8-octane and agents such as
methyl-3-[(p-azidophenyl- )dithio]propioimidate.
[0110] Other modifications include deamidation of glutaminyl and
asparaginyl residues to the corresponding glutamyl and aspartyl
residues, respectively, hydroxylation of proline and lysine,
phosphorylation of hydroxyl groups of seryl or threonyl residues,
methylation of the .alpha.-amino groups of lysine, arginine, and
histidine side chains [T. E. Creighton, Proteins: Structure and
Molecular Properties, W.H. Freeman & Co., San Francisco, pp.
79-86 (1983)], acetylation of the N-terminal amine, and amidation
of any C-terminal carboxyl group.
[0111] Another type of covalent modification of the PRO polypeptide
included within the scope of this invention comprises altering the
native glycosylation pattern of the polypeptide. "Altering the
native glycosylation pattern" is intended for purposes herein to
mean deleting one or more carbohydrate moieties found in native
sequence PRO (either by removing the underlying glycosylation site
or by deleting the glycosylation by chemical and/or enzymatic
means), and/or adding one or more glycosylation sites that are not
present in the native sequence PRO. In addition, the phrase
includes qualitative changes in the glycosylation of the native
proteins, involving a change in the nature and proportions of the
various carbohydrate moieties present.
[0112] Addition of glycosylation sites to the PRO polypeptide may
be accomplished by altering the amino acid sequence. The alteration
may be made, for example, by the addition of, or substitution by,
one or more serine or threonine residues to the native sequence PRO
(for O-linked glycosylation sites). The PRO amino acid sequence may
optionally be altered through changes at the DNA level,
particularly by mutating the DNA encoding the PRO polypeptide at
preselected bases such that codons are generated that will
translate into the desired amino acids.
[0113] Another means of increasing the number of carbohydrate
moieties on the PRO polypeptide is by chemical or enzymatic
coupling of glycosides to the polypeptide. Such methods are
described in the art, e.g., in WO 87/05330 published 11 Sep. 1987,
and in Aplin and Wriston, CRC Crit. Rev. Biochem., pp. 259-306
(1981).
[0114] Removal of carbohydrate moieties present on the PRO
polypeptide may be accomplished chemically or enzymatically or by
mutational substitution of codons encoding for amino acid residues
that serve as targets for glycosylation. Chemical deglycosylation
techniques are known in the art and described, for instance, by
Hakimuddin, et al., Arch. Biochem. Biophys., 259:52 (1987) and by
Edge et al., Anal. Biochem., 118:131 (1981). Enzymatic cleavage of
carbohydrate moieties on polypeptides can be achieved by the use of
a variety of endo- and exo-glycosidases as described by Thotakura
et al., Meth. Enzymol., 138:350 (1987).
[0115] Another type of covalent modification of PRO comprises
linking the PRO polypeptide to one of a variety of nonproteinaceous
polymers, e.g., polyethylene glycol (PEG), polypropylene glycol, or
polyoxyalkylenes, in the manner set forth in U.S. Pat. No.
4,640,835; 4,496,689; 4,301,144; 4,670,417; 4,791,192 or
4,179,337.
[0116] The PRO of the present invention may also be modified in a
way to form a chimeric molecule comprising PRO fused to another,
heterologous polypeptide or amino acid sequence.
[0117] In one embodiment, such a chimeric molecule comprises a
fusion of the PRO with a tag polypeptide which provides an epitope
to which an anti-tag antibody can selectively bind. The epitope tag
is generally placed at the amino- or carboxyl-terminus of the PRO.
The presence of such epitope-tagged forms of the PRO can be
detected using an antibody against the tag polypeptide. Also,
provision of the epitope tag enables the PRO to be readily purified
by affinity purification using an anti-tag antibody or another type
of affinity matrix that binds to the epitope tag. Various tag
polypeptides and their respective antibodies are well known in the
art. Examples include poly-histidine (poly-his) or
poly-histidine-glycine (poly-his-gly) tags; the flu HA tag
polypeptide and its antibody 12CA5 [Field et al., Mol. Cell. Biol.,
8:2159-2165 (1988)]; the c-myc tag and the 8F9, 3C7, 6E10, G4, B7
and 9E10 antibodies thereto [Evan et al., Molecular and Cellular
Biology, 5:3610-3616 (1985)]; and the Herpes Simplex virus
glycoprotein D (gD) tag and its antibody [Paborsky et al., Protein
Engineering, 3(6):547-553 (1990)]. Other tag polypeptides include
the Flag-peptide [Hopp et al., BioTechnology, 6:1204-1210 (1988)];
the KT3 epitope peptide [Martin et al., Science, 255:192-194
(1992)]; an .alpha.-tubulin epitope peptide [Skinner et al., J.
Biol. Chem., 266:15163-15166 (1991)]; and the T7 gene 10 protein
peptide tag [Lutz-Freyermuth et al., Proc. Natl. Acad. Sci. USA,
87:6393-6397 (1990)].
[0118] In an alternative embodiment, the chimeric molecule may
comprise a fusion of the PRO with an immunoglobulin or a particular
region of an immunoglobulin. For a bivalent form of the chimeric
molecule (also referred to as an "immunoadhesin"), such a fusion
could be to the Fc region of an IgG molecule. The Ig fusions
preferably include the substitution of a soluble (transmembrane
domain deleted or inactivated) form of a PRO polypeptide in place
of at least one variable region within an Ig molecule. In a
particularly preferred embodiment, the immunoglobulin fusion
includes the hinge, CH2 and CH3, or the hinge, CH1, CH2 and CH3
regions of an IgG1 molecule. For the production of immunoglobulin
fusions see also U.S. Pat. No. 5,428,130 issued Jun. 27, 1995.
[0119] D. Preparation of PRO
[0120] The description below relates primarily to production of PRO
by culturing cells transformed or transfected with a vector
containing PRO nucleic acid. It is, of course, contemplated that
alternative methods, which are well known in the art, may be
employed to prepare PRO. For instance, the PRO sequence, or
portions thereof, may be produced by direct peptide synthesis using
solid-phase techniques [see, e.g., Stewart et al., Solid-Phase
Peptide Synthesis, W.H. Freeman Co., San Francisco, Calif. (1969);
Merrifield, J. Am. Chem. Soc., 85:2149-2154 (1963)]. In vitro
protein synthesis may be performed using manual techniques or by
automation. Automated synthesis may be accomplished, for instance,
using an Applied Biosystems Peptide Synthesizer (Foster City,
Calif.) using manufacturer's instructions. Various portions of the
PRO may be chemically synthesized separately and combined using
chemical or enzymatic methods to produce the full-length PRO.
1. Isolation of DNA Encoding PRO
[0121] DNA encoding PRO may be obtained from a cDNA library
prepared from tissue believed to possess the PRO mRNA and to
express it at a detectable level. Accordingly, human PRO DNA can be
conveniently obtained from a cDNA library prepared from human
tissue, such as described in the Examples. The PRO-encoding gene
may also be obtained from a genomic library or by known synthetic
procedures (e.g., automated nucleic acid synthesis).
[0122] Libraries can be screened with probes (such as antibodies to
the PRO or oligonucleotides of at least about 20-80 bases) designed
to identify the gene of interest or the protein encoded by it.
Screening the cDNA or genomic library with the selected probe may
be conducted using standard procedures, such as described in
Sambrook et al., Molecular Cloning: A Laboratory Manual (New York:
Cold Spring Harbor Laboratory Press, 1989). An alternative means to
isolate the gene encoding PRO is to use PCR methodology [Sambrook
et al., supra; Dieffenbach et al., PCR Primer: A Laboratory Manual
(Cold Spring Harbor Laboratory Press, 1995)].
[0123] The Examples below describe techniques for screening a cDNA
library. The oligonucleotide sequences selected as probes should be
of sufficient length and sufficiently unambiguous that false
positives are minimized. The oligonucleotide is preferably labeled
such that it can be detected upon hybridization to DNA in the
library being screened. Methods of labeling are well known in the
art, and include the use of radiolabels like .sup.32P-labeled ATP,
biotinylation or enzyme labeling. Hybridization conditions,
including moderate stringency and high stringency, are provided in
Sambrook et al., supra.
[0124] Sequences identified in such library screening methods can
be compared and aligned to other known sequences deposited and
available in public databases such as GenBank or other private
sequence databases. Sequence identity (at either the amino acid or
nucleotide level) within defined regions of the molecule or across
the full-length sequence can be determined using methods known in
the art and as described herein.
[0125] Nucleic acid having protein coding sequence may be obtained
by screening selected cDNA or genomic libraries using the deduced
amino acid sequence disclosed herein for the first time, and, if
necessary, using conventional primer extension procedures as
described in Sambrook et al., supra, to detect precursors and
processing intermediates of mRNA that may not have been
reverse-transcribed into cDNA.
2. Selection and Transformation of Host Cells
[0126] Host cells are transfected or transformed with expression or
cloning vectors described herein for PRO production and cultured in
conventional nutrient media modified as appropriate for inducing
promoters, selecting transformants, or amplifying the genes
encoding the desired sequences. The culture conditions, such as
media, temperature, pH and the like, can be selected by the skilled
artisan without undue experimentation. In general, principles,
protocols, and practical techniques for maximizing the productivity
of cell cultures can be found in Mammalian Cell Biotechnology: a
Practical Approach, M. Butler, ed. (IRL Press, 1991) and Sambrook
et al., supra.
[0127] Methods of eukaryotic cell transfection and prokaryotic cell
transformation are known to the ordinarily skilled artisan, for
example, CaCl.sub.2, CaPO.sub.4, liposome-mediated and
electroporation. Depending on the host cell used, transformation is
performed using standard techniques appropriate to such cells. The
calcium treatment employing calcium chloride, as described in
Sambrook et al., supra, or electroporation is generally used for
prokaryotes. Infection with Agrobacterium tumefaciens is used for
transformation of certain plant cells, as described by Shaw et al.,
Gene, 23:315 (1983) and WO 89/05859 published 29 Jun. 1989. For
mammalian cells without such cell walls, the calcium phosphate
precipitation method of Graham and van der Eb, Virology, 52:456457
(1978) can be employed. General aspects of mammalian cell host
system transfections have been described in U.S. Pat. No.
4,399,216. Transformations into yeast are typically carried out
according to the method of Van Solingen et al., J. Bact., 130:946
(1977) and Hsiao et al., Proc. Natl. Acad. Sci. (USA), 76:3829
(1979). However, other methods for introducing DNA into cells, such
as by nuclear microinjection, electroporation, bacterial protoplast
fusion with intact cells, or polycations, e.g., polybrene,
polyornithine, may also be used. For various techniques for
transforming mammalian cells, see Keown et al., Methods in
Enzymology, 185:527-537 (1990) and Mansour et al., Nature,
336:348-352 (1988).
[0128] Suitable host cells for cloning or expressing the DNA in the
vectors herein include prokaryote, yeast, or higher eukaryote
cells. Suitable prokaryotes include but are not limited to
eubacteria, such as Gram-negative or Gram-positive organisms, for
example, Enterobacteriaceae such as E. coli. Various E. coli
strains are publicly available, such as E. coli K12 strain MM294
(ATCC 31,446); E. coli X1776 (ATCC 31,537); E. coli strain W3110
(ATCC 27,325) and K5 772 (ATCC 53,635). Other suitable prokaryotic
host cells include Enterobacteriaceae such as Escherichia, e.g., E.
coli, Enterobacter, Erwinia, Klebsiella, Proteus, Salmonella, e.g.,
Salmonella typhimurium, Serratia, e.g., Serratia marcescans, and
Shigella, as well as Bacilli such as B. subtilis and B.
licheniformis (e.g., B. licheniformis 41P disclosed in DD 266,710
published 12 Apr. 1989), Pseudomonas such as P. aeruginosa, and
Streptomyces. These examples are illustrative rather than limiting.
Strain W3110 is one particularly preferred host or parent host
because it is a common host strain for recombinant DNA product
fermentations. Preferably, the host cell secretes minimal amounts
of proteolytic enzymes. For example, strain W3110 may be modified
to effect a genetic mutation in the genes encoding proteins
endogenous to the host, with examples of such hosts including E.
coli W3110 strain 1A2, which has the complete genotype tonA; E.
coli W3110 strain 9E4, which has the complete genotype tonA ptr3;
E. coli W3110 strain 27C7 (ATCC 55,244), which has the complete
genotype tonA ptr3 phoA E15 (argF-lac)169 degP ompT kan.sup.r; E.
coli W3110 strain 37D6, which has the complete genotype tonA ptr3
phoA E15 (argF-lac)169 degP ompT rbs7ilvG kan.sup.r; E. coli W3110
strain 40B4, which is strain 37D6 with a non-kanamycin resistant
degP deletion mutation; and an E. coli strain having mutant
periplasmic protease disclosed in U.S. Pat. No. 4,946,783 issued 7
Aug. 1990. Alternatively, in vitro methods of cloning, e.g., PCR or
other nucleic acid polymerase reactions, are suitable.
[0129] In addition to prokaryotes, eukaryotic microbes such as
filamentous fungi or yeast are suitable cloning or expression hosts
for PRO-encoding vectors. Saccharomyces cerevisiae is a commonly
used lower eukaryotic host microorganism. Others include
Schizosaccharomyces pombe (Beach and Nurse, Nature, 290: 140
[1981]; EP 139,383 published 2 May 1985); Kluyveromyces hosts (U.S.
Pat. No. 4,943,529; Fleer et al., Bio/Technology, 9:968-975 (1991))
such as, e.g., K. lactis (MW98-8C, CBS683, CBS4574; Louvencourt et
al., J. Bacteriol., 154(2):737-742 [1983]), K. fragilis (ATCC
12,424), K. bulgaricus (ATCC 16,045), K. wickeramii (ATCC 24,178),
K. waltii (ATCC 56,500), K. drosophilarum (ATCC 36,906; Van den
Berg et al., Bio/Technology, 8:135 (1990)), K. thermotolerans, and
K. maxianus; yarrowia (EP402,226); Pichia pastoris (EP 183,070;
Sreekrishna et al., J. Basic Microbiol., 28:265-278 [1988]);
Candida; Trichoderma reesia (EP 244,234); Neurospora crassa (Case
et al., Proc. Natl. Acad. Sci. USA, 76:5259-5263 [1979]);
Schwanniomyces such as Schwanniomyces occidentalis (EP 394,538
published 31 Oct. 1990); and filamentous fungi such as, e.g.,
Neurospora, Penicillium, Tolypocladium (WO 91/00357 published 10
Jan. 1991), and Aspergillus hosts such as A. nidulans (Ballance et
al., Biochem. Biophys. Res. Commun., 112:284-289 [1983]; Tilburn et
al., Gene, 26:205-221 [1983]; Yelton et al., Proc. Natl. Acad. Sci.
USA, 81: 1470-1474 [1984]) and A. niger (Kelly and Hynes, EMBO J.,
4:475-479 [1985]). Methylotropic yeasts are suitable herein and
include, but are not limited to, yeast capable of growth on
methanol selected from the genera consisting of Hansenula, Candida,
Kloeckera, Pichia, Saccharomyces, Torulopsis, and Rhodotorula. A
list of specific species that are exemplary of this class of yeasts
may be found in C. Anthony, The Biochemistry of Methylotrophs, 269
(1982).
[0130] Suitable host cells for the expression of glycosylated PRO
are derived from multicellular organisms. Examples of invertebrate
cells include insect cells such as Drosophila S2 and Spodoptera
Sf9, as well as plant cells. Examples of useful mammalian host cell
lines include Chinese hamster ovary (CHO) and COS cells. More
specific examples include monkey kidney CV1 line transformed by
SV40 (COS-7, ATCC CRL 1651); human embryonic kidney line (293 or
293 cells subcloned for growth in suspension culture, Graham et
al., J. Gen Virol., 36:59 (1977)); Chinese hamster ovary
cells/-DHFR (CHO, Urlaub and Chasin, Proc. Natl. Acad. Sci. USA,
77:4216 (1980)); mouse sertoli cells (TM4, Mather, Biol. Reprod.,
23:243-251 (1980)); human lung cells (W138, ATCC CCL75); human
liver cells (Hep G2, HB 8065); and mouse mammary tumor (MMT 060562,
ATCC CCL51). The selection of the appropriate host cell is deemed
to be within the skill in the art.
3. Selection and Use of a Replicable Vector
[0131] The nucleic acid (e.g., cDNA or genomic DNA) encoding PRO
may be inserted into a replicable vector for cloning (amplification
of the DNA) or for expression. Various vectors are publicly
available. The vector may, for example, be in the form of a
plasmid, cosmid, viral particle, or phage. The appropriate nucleic
acid sequence may be inserted into the vector by a variety of
procedures. In general, DNA is inserted into an appropriate
restriction endonuclease site(s) using techniques known in the art.
Vector components generally include, but are not limited to, one or
more of a signal sequence, an origin of replication, one or more
marker genes, an enhancer element, a promoter, and a transcription
termination sequence. Construction of suitable vectors containing
one or more of these components employs standard ligation
techniques which are known to the skilled artisan.
[0132] The PRO may be produced recombinantly not only directly, but
also as a fusion polypeptide with a heterologous polypeptide, which
may be a signal sequence or other polypeptide having a specific
cleavage site at the N-terminus of the mature protein or
polypeptide. In general, the signal sequence may be a component of
the vector, or it may be a part of the PRO-encoding DNA that is
inserted into the vector. The signal sequence may be a prokaryotic
signal sequence selected, for example, from the group of the
alkaline phosphatase, penicillinase, lpp, or heat-stable
enterotoxin II leaders. For yeast secretion the signal sequence may
be, e.g., the yeast invertase leader, alpha factor leader
(including Saccharomyces and Kluyveromyces .alpha.-factor leaders,
the latter described in U.S. Pat. No. 5,010,182), or acid
phosphatase leader, the C. albicans glucoamylase leader (EP 362,179
published 4 Apr. 1990), or the signal described in WO 90/13646
published 15 Nov. 1990. In mammalian cell expression, mammalian
signal sequences may be used to direct secretion of the protein,
such as signal sequences from secreted polypeptides of the same or
related species, as well as viral secretory leaders.
[0133] Both expression and cloning vectors contain a nucleic acid
sequence that enables the vector to replicate in one or more
selected host cells. Such sequences are well known for a variety of
bacteria, yeast, and viruses. The origin of replication from the
plasmid pBR322 is suitable for most Gram-negative bacteria, the
2.mu. plasmid origin is suitable for yeast, and various viral
origins (SV40, polyoma, adenovirus, VSV or BPV) are useful for
cloning vectors in mammalian cells.
[0134] Expression and cloning vectors will typically contain a
selection gene, also termed a selectable marker. Typical selection
genes encode proteins that (a) confer resistance to antibiotics or
other toxins, e.g., ampicillin, neomycin, methotrexate, or
tetracycline, (b) complement auxotrophic deficiencies, or (c)
supply critical nutrients not available from complex media, e.g.,
the gene encoding D-alanine racemase for Bacilli.
[0135] An example of suitable selectable markers for mammalian
cells are those that enable the identification of cells competent
to take up the PRO-encoding nucleic acid, such as DHFR or thymidine
kinase. An appropriate host cell when wild-type DHFR is employed is
the CHO cell line deficient in DHFR activity, prepared and
propagated as described by Urlaub et al., Proc. Natl. Acad. Sci.
USA, 77:4216 (1980). A suitable selection gene for use in yeast is
the trp1 gene present in the yeast plasmid YRp7 [Stinchcomb et al.,
Nature, 282:39 (1979); Kingsman et al., Gene, 7:141 (1979);
Tschemper et al., Gene, 10:157 (1980)]. The trp1 gene provides a
selection marker for a mutant strain of yeast lacking the ability
to grow in tryptophan, for example, ATCC No. 44076 or PEP4-1
[Jones, Genetics, 85:12 (1977)].
[0136] Expression and cloning vectors usually contain a promoter
operably linked to the PRO-encoding nucleic acid sequence to direct
mRNA synthesis. Promoters recognized by a variety of potential host
cells are well known. Promoters suitable for use with prokaryotic
hosts include the .beta.-lactamase and lactose promoter systems
[Chang et al., Nature, 275:615 (1978); Goeddel et al., Nature,
281:544 (1979)], alkaline phosphatase, a tryptophan (trp) promoter
system [Goeddel, Nucleic Acids Res., 8:4057 (1980); EP 36,776], and
hybrid promoters such as the tac promoter [deBoer et al., Proc.
Natl. Acad. Sci. USA, 80:21-25 (1983)]. Promoters for use in
bacterial systems also will contain a Shine-Dalgarno (S.D.)
sequence operably linked to the DNA encoding PRO.
[0137] Examples of suitable promoting sequences for use with yeast
hosts include the promoters for 3-phosphoglycerate kinase [Hitzeman
et al., J. Biol. Chem., 255:2073 (1980)] or other glycolytic
enzymes [Hess et al., J. Adv. Enzyme Reg., 7:149 (1968); Holland,
Biochemistry, 17:4900 (1978)], such as enolase,
glyceraldehyde-3-phosphate dehydrogenase, hexokinase, pyruvate
decarboxylase, phosphofructokinase, glucose-6-phosphate isomerase,
3-phosphoglycerate mutase, pyruvate kinase, triosephosphate
isomerase, phosphoglucose isomerase, and glucokinase.
[0138] Other yeast promoters, which are inducible promoters having
the additional advantage of transcription controlled by growth
conditions, are the promoter regions for alcohol dehydrogenase 2,
isocytochrome C, acid phosphatase, degradative enzymes associated
with nitrogen metabolism, metallothionein,
glyceraldehyde-3-phosphate dehydrogenase, and enzymes responsible
for maltose and galactose utilization. Suitable vectors and
promoters for use in yeast expression are further described in EP
73,657.
[0139] PRO transcription from vectors in mammalian host cells is
controlled, for example, by promoters obtained from the genomes of
viruses such as polyoma virus, fowlpox virus (UK 2,211,504
published 5 Jul. 1989), adenovirus (such as Adenovirus 2), bovine
papilloma virus, avian sarcoma virus, cytomegalovirus, a
retrovirus, hepatitis-B virus and Simian Virus 40 (SV40), from
heterologous mammalian promoters, e.g., the actin promoter or an
immunoglobulin promoter, and from heat-shock promoters, provided
such promoters are compatible with the host cell systems.
[0140] Transcription of a DNA encoding the PRO by higher eukaryotes
may be increased by inserting an enhancer sequence into the vector.
Enhancers are cis-acting elements of DNA, usually about from 10 to
300 bp, that act on a promoter to increase its transcription. Many
enhancer sequences are now known from mammalian genes (globin,
elastase, albumin, .alpha.-fetoprotein, and insulin). Typically,
however, one will use an enhancer from a eukaryotic cell virus.
Examples include the SV40 enhancer on the late side of the
replication origin (bp 100-270), the cytomegalovirus early promoter
enhancer, the polyoma enhancer on the late side of the replication
origin, and adenovirus enhancers. The enhancer may be spliced into
the vector at a position 5' or 3' to the PRO coding sequence, but
is preferably located at a site 5' from the promoter.
[0141] Expression vectors used in eukaryotic host cells (yeast,
fungi, insect, plant, animal, human, or nucleated cells from other
multicellular organisms) will also contain sequences necessary for
the termination of transcription and for stabilizing the mRNA. Such
sequences are commonly available from the 5' and, occasionally 3',
untranslated regions of eukaryotic or viral DNAs or cDNAs. These
regions contain nucleotide segments transcribed as polyadenylated
fragments in the untranslated portion of the mRNA encoding PRO.
[0142] Still other methods, vectors, and host cells suitable for
adaptation to the synthesis of PRO in recombinant vertebrate cell
culture are described in Gething et al., Nature, 293:620-625
(1981); Mantei et al., Nature, 281:40-46 (1979); EP 117,060; and EP
117,058.
4. Detecting Gene Amplification/Expression
[0143] Gene amplification and/or expression may be measured in a
sample directly, for example, by conventional Southern blotting,
Northern blotting to quantitate the transcription of mRNA [Thomas,
Proc. Natl. Acad. Sci. USA, 77:5201-5205 (1980)], dot blotting (DNA
analysis), or in situ hybridization, using an appropriately labeled
probe, based on the sequences provided herein. Alternatively,
antibodies may be employed that can recognize specific duplexes,
including DNA duplexes, RNA duplexes, and DNA-RNA hybrid duplexes
or DNA-protein duplexes. The antibodies in turn may be labeled and
the assay may be carried out where the duplex is bound to a
surface, so that upon the formation of duplex on the surface, the
presence of antibody bound to the duplex can be detected.
[0144] Gene expression, alternatively, may be measured by
immunological methods, such as immunohistochemical staining of
cells or tissue sections and assay of cell culture or body fluids,
to quantitate directly the expression of gene product. Antibodies
useful for immunohistochemical staining and/or assay of sample
fluids may be either monoclonal or polyclonal, and may be prepared
in any mammal. Conveniently, the antibodies may be prepared against
a native sequence PRO polypeptide or against a synthetic peptide
based on the DNA sequences provided herein or against exogenous
sequence fused to PRO DNA and encoding a specific antibody
epitope.
5. Purification of Polypeptide
[0145] Forms of PRO may be recovered from culture medium or from
host cell lysates. If membrane-bound, it can be released from the
membrane using a suitable detergent solution (e.g. Triton-X 100) or
by enzymatic cleavage. Cells employed in expression of PRO can be
disrupted by various physical or chemical means, such as
freeze-thaw cycling, sonication, mechanical disruption, or cell
lysing agents.
[0146] It may be desired to purify PRO from recombinant cell
proteins or polypeptides. The following procedures are exemplary of
suitable purification procedures: by fractionation on an
ion-exchange column; ethanol precipitation; reverse phase HPLC;
chromatography on silica or on a cation-exchange resin such as
DEAE; chromatofocusing; SDS-PAGE; ammonium sulfate precipitation;
gel filtration using, for example, Sephadex G-75; protein A
Sepharose columns to remove contaminants such as IgG; and metal
chelating columns to bind epitope-tagged forms of the PRO. Various
methods of protein purification may be employed and such methods
are known in the art and described for example in Deutscher,
Methods in Enzymology, 182 (1990); Scopes, Protein Purification:
Principles and Practice, Springer-Verlag, New York (1982). The
purification step(s) selected will depend, for example, on the
nature of the production process used and the particular PRO
produced.
[0147] E. Uses for PRO
[0148] Nucleotide sequences (or their complement) encoding PRO have
various applications in the art of molecular biology, including
uses as hybridization probes, in chromosome and gene mapping and in
the generation of anti-sense RNA and DNA. PRO nucleic acid will
also be useful for the preparation of PRO polypeptides by the
recombinant techniques described herein.
[0149] The full-length native sequence PRO gene, or portions
thereof, may be used as hybridization probes for a cDNA library to
isolate the full-length PRO cDNA or to isolate still other cDNAs
(for instance, those encoding naturally-occurring variants of PRO
or PRO from other species) which have a desired sequence identity
to the native PRO sequence disclosed herein. Optionally, the length
of the probes will be about 20 to about 50 bases. The hybridization
probes may be derived from at least partially novel regions of the
full length native nucleotide sequence wherein those regions may be
determined without undue experimentation or from genomic sequences
including promoters, enhancer elements and introns of native
sequence PRO. By way of example, a screening method will comprise
isolating the coding region of the PRO gene using the known DNA
sequence to synthesize a selected probe of about 40 bases.
Hybridization probes may be labeled by a variety of labels,
including radionucleotides such as .sup.32P or .sup.35S, or
enzymatic labels such as alkaline phosphatase coupled to the probe
via avidin/biotin coupling systems. Labeled probes having a
sequence complementary to that of the PRO gene of the present
invention can be used to screen libraries of human cDNA, genomic
DNA or mRNA to determine which members of such libraries the probe
hybridizes to. Hybridization techniques are described in further
detail in the Examples below.
[0150] Any EST sequences disclosed in the present application may
similarly be employed as probes, using the methods disclosed
herein.
[0151] Other useful fragments of the PRO nucleic acids include
antisense or sense oligonucleotides comprising a singe-stranded
nucleic acid sequence (either RNA or DNA) capable of binding to
target PRO mRNA (sense) or PRO DNA (antisense) sequences. Antisense
or sense oligonucleotides, according to the present invention,
comprise a fragment of the coding region of PRO DNA. Such a
fragment generally comprises at least about 14 nucleotides,
preferably from about 14 to 30 nucleotides. The ability to derive
an antisense or a sense oligonucleotide, based upon a cDNA sequence
encoding a given protein is described in, for example, Stein and
Cohen (Cancer Res. 48:2659, 1988) and van der Krol et al.
(BioTechniques 6:958, 1988).
[0152] Binding of antisense or sense oligonucleotides to target
nucleic acid sequences results in the formation of duplexes that
block transcription or translation of the target sequence by one of
several means, including enhanced degradation of the duplexes,
premature termination of transcription or translation, or by other
means. The antisense oligonucleotides thus may be used to block
expression of PRO proteins. Antisense or sense oligonucleotides
further comprise oligonucleotides having modified
sugar-phosphodiester backbones (or other sugar linkages, such as
those described in WO 91/06629) and wherein such sugar linkages are
resistant to endogenous nucleases. Such oligonucleotides with
resistant sugar linkages are stable in vivo (i.e., capable of
resisting enzymatic degradation) but retain sequence specificity to
be able to bind to target nucleotide sequences.
[0153] Other examples of sense or antisense oligonucleotides
include those oligonucleotides which are covalently linked to
organic moieties, such as those described in WO 90/10048, and other
moieties that increases affinity of the oligonucleotide for a
target nucleic acid sequence, such as poly-(L-lysine). Further
still, intercalating agents, such as ellipticine, and alkylating
agents or metal complexes may be attached to sense or antisense
oligonucleotides to modify binding specificities of the antisense
or sense oligonucleotide for the target nucleotide sequence.
[0154] Antisense or sense oligonucleotides may be introduced into a
cell containing the target nucleic acid sequence by any gene
transfer method, including, for example, CaPO.sub.4-mediated DNA
transfection, electroporation, or by using gene transfer vectors
such as Epstein-Barr virus. In a preferred procedure, an antisense
or sense oligonucleotide is inserted into a suitable retroviral
vector. A cell containing the target nucleic acid sequence is
contacted with the recombinant retroviral vector, either in vivo or
ex vivo. Suitable retroviral vectors include, but are not limited
to, those derived from the murine retrovirus M-MuLV, N2 (a
retrovirus derived from M-MuLV), or the double copy vectors
designated DCT5A, DCT5B and DCT5C (see WO 90/13641).
[0155] Sense or antisense oligonucleotides also may be introduced
into a cell containing the target nucleotide sequence by formation
of a conjugate with a ligand binding molecule, as described in WO
91/04753. Suitable ligand binding molecules include, but are not
limited to, cell surface receptors, growth factors, other
cytokines, or other ligands that bind to cell surface receptors.
Preferably, conjugation of the ligand binding molecule does not
substantially interfere with the ability of the ligand binding
molecule to bind to its corresponding molecule or receptor, or
block entry of the sense or antisense oligonucleotide or its
conjugated version into the cell.
[0156] Alternatively, a sense or an antisense oligonucleotide may
be introduced into a cell containing the target nucleic acid
sequence by formation of an oligonucleotide-lipid complex, as
described in WO 90/10448. The sense or antisense
oligonucleotide-lipid complex is preferably dissociated within the
cell by an endogenous lipase.
[0157] Antisense or sense RNA or DNA molecules are generally at
least about 5 bases in length, about 10 bases in length, about 15
bases in length, about 20 bases in length, about 25 bases in
length, about 30 bases in length, about 35 bases in length, about
40 bases in length, about 45 bases in length, about 50 bases in
length, about 55 bases in length, about 60 bases in length, about
65 bases in length, about 70 bases in length, about 75 bases in
length, about 80 bases in length, about 85 bases in length, about
90 bases in length, about 95 bases in length, about 100 bases in
length, or more.
[0158] The probes may also be employed in PCR techniques to
generate a pool of sequences for identification of closely related
PRO coding sequences.
[0159] Nucleotide sequences encoding a PRO can also be used to
construct hybridization probes for mapping the gene which encodes
that PRO and for the genetic analysis of individuals with genetic
disorders. The nucleotide sequences provided herein may be mapped
to a chromosome and specific regions of a chromosome using known
techniques, such as in situ hybridization, linkage analysis against
known chromosomal markers, and hybridization screening with
libraries.
[0160] When the coding sequences for PRO encode a protein which
binds to another protein (example, where the PRO is a receptor),
the PRO can be used in assays to identify the other proteins or
molecules involved in the binding interaction. By such methods,
inhibitors of the receptor/ligand binding interaction can be
identified. Proteins involved in such binding interactions can also
be used to screen for peptide or small molecule inhibitors or
agonists of the binding interaction. Also, the receptor PRO can be
used to isolate correlative ligand(s). Screening assays can be
designed to find lead compounds that mimic the biological activity
of a native PRO or a receptor for PRO. Such screening assays will
include assays amenable to high-throughput screening of chemical
libraries, making them particularly suitable for identifying small
molecule drug candidates. Small molecules contemplated include
synthetic organic or inorganic compounds. The assays can be
performed in a variety of formats, including protein-protein
binding assays, biochemical screening assays, immunoassays and cell
based assays, which are well characterized in the art.
[0161] Nucleic acids which encode PRO or its modified forms can
also be used to generate either transgenic animals or "knock out"
animals which, in turn, are useful in the development and screening
of therapeutically useful reagents. A transgenic animal (e.g., a
mouse or rat) is an animal having cells that contain a transgene,
which transgene was introduced into the animal or an ancestor of
the animal at a prenatal, e.g., an embryonic stage. A transgene is
a DNA which is integrated into the genome of a cell from which a
transgenic animal develops. In one embodiment, cDNA encoding PRO
can be used to clone genomic DNA encoding PRO in accordance with
established techniques and the genomic sequences used to generate
transgenic animals that contain cells which express DNA encoding
PRO. Methods for generating transgenic animals, particularly
animals such as mice or rats, have become conventional in the art
and are described, for example, in U.S. Pat. Nos. 4,736,866 and
4,870,009. Typically, particular cells would be targeted for PRO
transgene incorporation with tissue-specific enhancers. Transgenic
animals that include a copy of a transgene encoding PRO introduced
into the germ line of the animal at an embryonic stage can be used
to examine the effect of increased expression of DNA encoding PRO.
Such animals can be used as tester animals for reagents thought to
confer protection from, for example, pathological conditions
associated with its overexpression. In accordance with this facet
of the invention, an animal is treated with the reagent and a
reduced incidence of the pathological condition, compared to
untreated animals bearing the transgene, would indicate a potential
therapeutic intervention for the pathological condition.
[0162] Alternatively, non-human homologues of PRO can be used to
construct a PRO "knock out" animal which has a defective or altered
gene encoding PRO as a result of homologous recombination between
the endogenous gene encoding PRO and altered genomic DNA encoding
PRO introduced into an embryonic stem cell of the animal. For
example, cDNA encoding PRO can be used to clone genomic DNA
encoding PRO in accordance with established techniques. A portion
of the genomic DNA encoding PRO can be deleted or replaced with
another gene, such as a gene encoding a selectable marker which can
be used to monitor integration. Typically, several kilobases of
unaltered flanking DNA (both at the 5' and 3' ends) are included in
the vector [see e.g., Thomas and Capecchi, Cell, 51:503 (1987) for
a description of homologous recombination vectors]. The vector is
introduced into an embryonic stem cell line (e.g., by
electroporation) and cells in which the introduced DNA has
homologously recombined with the endogenous DNA are selected [see
e.g., Li et al., Cell, 69:915 (1992)]. The selected cells are then
injected into a blastocyst of an animal (e.g., a mouse or rat) to
form aggregation chimeras [see e.g., Bradley, in Teratocarcinomas
and Embryonic Stem Cells. A Practical Approach, E. J. Robertson,
ed. (IRL, Oxford, 1987), pp. 113-152]. A chimeric embryo can then
be implanted into a suitable pseudopregnant female foster animal
and the embryo brought to term to create a "knock out" animal.
Progeny harboring the homologously recombined DNA in their germ
cells can be identified by standard techniques and used to breed
animals in which all cells of the animal contain the homologously
recombined DNA. Knockout animals can be characterized for instance,
for their ability to defend against certain pathological conditions
and for their development of pathological conditions due to absence
of the PRO polypeptide.
[0163] Nucleic acid encoding the PRO polypeptides may also be used
in gene therapy. In gene therapy applications, genes are introduced
into cells in order to achieve in vivo synthesis of a
therapeutically effective genetic product, for example for
replacement of a defective gene. "Gene therapy" includes both
conventional gene therapy where a lasting effect is achieved by a
single treatment, and the administration of gene therapeutic
agents, which involves the one time or repeated administration of a
therapeutically effective DNA or mRNA. Antisense RNAs and DNAs can
be used as therapeutic agents for blocking the expression of
certain genes in vivo. It has already been shown that short
antisense oligonucleotides can be imported into cells where they
act as inhibitors, despite their low intracellular concentrations
caused by their restricted uptake by the cell membrane. (Zamecnik
et al., Proc. Natl. Acad. Sci. USA 83:4143-4146 [1986]). The
oligonucleotides can be modified to enhance their uptake, e.g. by
substituting their negatively charged phosphodiester groups by
uncharged groups.
[0164] There are a variety of techniques available for introducing
nucleic acids into viable cells. The techniques vary depending upon
whether the nucleic acid is transferred into cultured cells in
vitro, or in vivo in the cells of the intended host. Techniques
suitable for the transfer of nucleic acid into mammalian cells in
vitro include the use of liposomes, electroporation,
microinjection, cell fusion, DEAE-dextran, the calcium phosphate
precipitation method, etc. The currently preferred in vivo gene
transfer techniques include transfection with viral (typically
retroviral) vectors and viral coat protein-liposome mediated
transfection (Dzau et al., Trends in Biotechnology 11, 205-210
[1993]). In some situations it is desirable to provide the nucleic
acid source with an agent that targets the target cells, such as an
antibody specific for a cell surface membrane protein or the target
cell, a ligand for a receptor on the target cell, etc. Where
liposomes are employed, proteins which bind to a cell surface
membrane protein associated with endocytosis may be used for
targeting and/or to facilitate uptake, e.g. capsid proteins or
fragments thereof tropic for a particular cell type, antibodies for
proteins which undergo internalization in cycling, proteins that
target intracellular localization and enhance intracellular
half-life. The technique of receptor-mediated endocytosis is
described, for example, by Wu et al., J. Biol. Chem. 262, 4429-4432
(1987); and Wagner et al., Proc. Natl. Acad. Sci. USA 87, 3410-3414
(1990). For review of gene marking and gene therapy protocols see
Anderson et al., Science 256, 808-813 (1992).
[0165] The PRO polypeptides described herein may also be employed
as molecular weight markers for protein electrophoresis purposes
and the isolated nucleic acid sequences may be used for
recombinantly expressing those markers.
[0166] The nucleic acid molecules encoding the PRO polypeptides or
fragments thereof described herein are useful for chromosome
identification. In this regard, there exists an ongoing need to
identify new chromosome markers, since relatively few chromosome
marking reagents, based upon actual sequence data are presently
available. Each PRO nucleic acid molecule of the present invention
can be used as a chromosome marker.
[0167] The PRO polypeptides and nucleic acid molecules of the
present invention may also be used diagnostically for tissue
typing, wherein the PRO polypeptides of the present invention may
be differentially expressed in one tissue as compared to another,
preferably in a diseased tissue as compared to a normal tissue of
the same tissue type. PRO nucleic acid molecules will find use for
generating probes for PCR, Northern analysis, Southern analysis and
Western analysis.
[0168] The PRO polypeptides described herein may also be employed
as therapeutic agents. The PRO polypeptides of the present
invention can be formulated according to known methods to prepare
pharmaceutically useful compositions, whereby the PRO product
hereof is combined in admixture with a pharmaceutically acceptable
carrier vehicle. Therapeutic formulations are prepared for storage
by mixing the active ingredient having the desired degree of purity
with optional physiologically acceptable carriers, excipients or
stabilizers (Remington's Pharmaceutical Sciences 16th edition,
Osol, A. Ed. (1980)), in the form of lyophilized formulations or
aqueous solutions. Acceptable carriers, excipients or stabilizers
are nontoxic to recipients at the dosages and concentrations
employed, and include buffers such as phosphate, citrate and other
organic acids; antioxidants including ascorbic acid; low molecular
weight (less than about 10 residues) polypeptides; proteins, such
as serum albumin, gelatin or immunoglobulins; hydrophilic polymers
such as polyvinylpyrrolidone, amino acids such as glycine,
glutamine, asparagine, arginine or lysine; monosaccharides,
disaccharides and other carbohydrates including glucose, mannose,
or dextrins; chelating agents such as EDTA; sugar alcohols such as
mannitol or sorbitol; salt-forming counterions such as sodium;
and/or nonionic surfactants such as TWEEN.TM., PLURONICS.TM. or
PEG.
[0169] The formulations to be used for in vivo administration must
be sterile. This is readily accomplished by filtration through
sterile filtration membranes, prior to or following lyophilization
and reconstitution.
[0170] Therapeutic compositions herein generally are placed into a
container having a sterile access port, for example, an intravenous
solution bag or vial having a stopper pierceable by a hypodermic
injection needle.
[0171] The route of administration is in accord with known methods,
e.g. injection or infusion by intravenous, intraperitoneal,
intracerebral, intramuscular, intraocular, intraarterial or
intralesional routes, topical administration, or by sustained
release systems.
[0172] Dosages and desired drug concentrations of pharmaceutical
compositions of the present invention may vary depending on the
particular use envisioned. The determination of the appropriate
dosage or route of administration is well within the skill of an
ordinary physician. Animal experiments provide reliable guidance
for the determination of effective doses for human therapy.
Interspecies scaling of effective doses can be performed following
the principles laid down by Mordenti, J. and Chappell, W. "The use
of interspecies scaling in toxicokinetics" In Toxicokinetics and
New Drug Development, Yacobi et al., Eds., Pergamon Press, New York
1989, pp. 42-96.
[0173] When in vivo administration of a PRO polypeptide or agonist
or antagonist thereof is employed, normal dosage amounts may vary
from about 10 ng/kg to up to 100 mg/kg of mammal body weight or
more per day, preferably about 1 .mu.g/kg/day to 10 mg/kg/day,
depending upon the route of administration. Guidance as to
particular dosages and methods of delivery is provided in the
literature; see, for example, U.S. Pat. No. 4,657,760; 5,206,344;
or 5,225,212. It is anticipated that different formulations will be
effective for different treatment compounds and different
disorders, that administration targeting one organ or tissue, for
example, may necessitate delivery in a manner different from that
to another organ or tissue.
[0174] Where sustained-release administration of a PRO polypeptide
is desired in a formulation with release characteristics suitable
for the treatment of any disease or disorder requiring
administration of the PRO polypeptide, microencapsulation of the
PRO polypeptide is contemplated. Microencapsulation of recombinant
proteins for sustained release has been successfully performed with
human growth hormone (rhGH), interferon- (rhIFN-), interleukin-2,
and MN rgp120. Johnson et al., Nat. Med., 2:795-799 (1996); Yasuda,
Biomed. Ther., 27:1221-1223 (1993); Hora et al., Bio/Technology,
8:755-758 (1990); Cleland, "Design and Production of Single
Immunization Vaccines Using Polylactide Polyglycolide Microsphere
Systems," in Vaccine Design: The Subunit and Adjuvant Approach,
Powell and Newman, eds, (Plenum Press: New York, 1995), pp.
439-462; WO 97/03692, WO 96/40072, WO 96/07399; and U.S. Pat. No.
5,654,010.
[0175] The sustained-release formulations of these proteins were
developed using poly-lactic-coglycolic acid (PLGA) polymer due to
its biocompatibility and wide range of biodegradable properties.
The degradation products of PLGA, lactic and glycolic acids, can be
cleared quickly within the human body. Moreover, the degradability
of this polymer can be adjusted from months to years depending on
its molecular weight and composition. Lewis, "Controlled release of
bioactive agents from lactide/glycolide polymer," in: M. Chasin and
R. Langer (Eds.), Biodegradable Polymers as Drug Delivery Systems
(Marcel Dekker: New York, 1990), pp. 1-41.
[0176] This invention encompasses methods of screening compounds to
identify those that mimic the PRO polypeptide (agonists) or prevent
the effect of the PRO polypeptide (antagonists). Screening assays
for antagonist drug candidates are designed to identify compounds
that bind or complex with the PRO polypeptides encoded by the genes
identified herein, or otherwise interfere with the interaction of
the encoded polypeptides with other cellular proteins. Such
screening assays will include assays amenable to high-throughput
screening of chemical libraries, making them particularly suitable
for identifying small molecule drug candidates.
[0177] The assays can be performed in a variety of formats,
including protein-protein binding assays, biochemical screening
assays, immunoassays, and cell-based assays, which are well
characterized in the art.
[0178] All assays for antagonists are common in that they call for
contacting the drug candidate with a PRO polypeptide encoded by a
nucleic acid identified herein under conditions and for a time
sufficient to allow these two components to interact.
[0179] In binding assays, the interaction is binding and the
complex formed can be isolated or detected in the reaction mixture.
In a particular embodiment, the PRO polypeptide encoded by the gene
identified herein or the drug candidate is immobilized on a solid
phase, e.g., on a microtiter plate, by covalent or non-covalent
attachments. Non-covalent attachment generally is accomplished by
coating the solid surface with a solution of the PRO polypeptide
and drying. Alternatively, an immobilized antibody, e.g., a
monoclonal antibody, specific for the PRO polypeptide to be
immobilized can be used to anchor it to a solid surface. The assay
is performed by adding the non-immobilized component, which may be
labeled by a detectable label, to the immobilized component, e.g.,
the coated surface containing the anchored component. When the
reaction is complete, the non-reacted components are removed, e.g.,
by washing, and complexes anchored on the solid surface are
detected. When the originally non-immobilized component carries a
detectable label, the detection of label immobilized on the surface
indicates that complexing occurred. Where the originally
non-immobilized component does not carry a label, complexing can be
detected, for example, by using a labeled antibody specifically
binding the immobilized complex.
[0180] If the candidate compound interacts with but does not bind
to a particular PRO polypeptide encoded by a gene identified
herein, its interaction with that polypeptide can be assayed by
methods well known for detecting protein-protein interactions. Such
assays include traditional approaches, such as, e.g.,
cross-linking, co-immunoprecipitation, and co-purification through
gradients or chromatographic columns. In addition, protein-protein
interactions can be monitored by using a yeast-based genetic system
described by Fields and co-workers (Fields and Song, Nature
(London), 340:245-246 (1989); Chien et al., Proc. Natl. Acad. Sci.
USA, 88:9578-9582 (1991)) as disclosed by Chevray and Nathans,
Proc. Natl. Acad. Sci. USA, 89: 5789-5793 (1991). Many
transcriptional activators, such as yeast GAL4, consist of two
physically discrete modular domains, one acting as the DNA-binding
domain, the other one functioning as the transcription-activation
domain. The yeast expression system described in the foregoing
publications (generally referred to as the "two-hybrid system")
takes advantage of this property, and employs two hybrid proteins,
one in which the target protein is fused to the DNA-binding domain
of GAL4, and another, in which candidate activating proteins are
fused to the activation domain. The expression of a GAL1-lacZ
reporter gene under control of a GAL4-activated promoter depends on
reconstitution of GAL4 activity via protein-protein interaction.
Colonies containing interacting polypeptides are detected with a
chromogenic substrate for .beta.-galactosidase. A complete kit
(MATCHMAKER.TM.) for identifying protein-protein interactions
between two specific proteins using the two-hybrid technique is
commercially available from Clontech. This system can also be
extended to map protein domains involved in specific protein
interactions as well as to pinpoint amino acid residues that are
crucial for these interactions.
[0181] Compounds that interfere with the interaction of a gene
encoding a PRO polypeptide identified herein and other intra- or
extracellular components can be tested as follows: usually a
reaction mixture is prepared containing the product of the gene and
the intra- or extracellular component under conditions and for a
time allowing for the interaction and binding of the two products.
To test the ability of a candidate compound to inhibit binding, the
reaction is run in the absence and in the presence of the test
compound. In addition, a placebo may be added to a third reaction
mixture, to serve as positive control. The binding (complex
formation) between the test compound and the intra- or
extracellular component present in the mixture is monitored as
described hereinabove. The formation of a complex in the control
reaction(s) but not in the reaction mixture containing the test
compound indicates that the test compound interferes with the
interaction of the test compound and its reaction partner.
[0182] To assay for antagonists, the PRO polypeptide may be added
to a cell along with the compound to be screened for a particular
activity and the ability of the compound to inhibit the activity of
interest in the presence of the PRO polypeptide indicates that the
compound is an antagonist to the PRO polypeptide. Alternatively,
antagonists may be detected by combining the PRO polypeptide and a
potential antagonist with membrane-bound PRO polypeptide receptors
or recombinant receptors under appropriate conditions for a
competitive inhibition assay. The PRO polypeptide can be labeled,
such as by radioactivity, such that the number of PRO polypeptide
molecules bound to the receptor can be used to determine the
effectiveness of the potential antagonist. The gene encoding the
receptor can be identified by numerous methods known to those of
skill in the art, for example, ligand panning and FACS sorting.
Coligan et al., Current Protocols in Immun., 1(2): Chapter 5
(1991). Preferably, expression cloning is employed wherein
polyadenylated RNA is prepared from a cell responsive to the PRO
polypeptide and a cDNA library created from this RNA is divided
into pools and used to transfect COS cells or other cells that are
not responsive to the PRO polypeptide. Transfected cells that are
grown on glass slides are exposed to labeled PRO polypeptide. The
PRO polypeptide can be labeled by a variety of means including
iodination or inclusion of a recognition site for a site-specific
protein kinase. Following fixation and incubation, the slides are
subjected to autoradiographic analysis. Positive pools are
identified and sub-pools are prepared and re-transfected using an
interactive sub-pooling and re-screening process, eventually
yielding a single clone that encodes the putative receptor.
[0183] As an alternative approach for receptor identification,
labeled PRO polypeptide can be photoaffinity-linked with cell
membrane or extract preparations that express the receptor
molecule. Cross-linked material is resolved by PAGE and exposed to
X-ray film. The labeled complex containing the receptor can be
excised, resolved into peptide fragments, and subjected to protein
micro-sequencing. The amino acid sequence obtained from
micro-sequencing would be used to design a set of degenerate
oligonucleotide probes to screen a cDNA library to identify the
gene encoding the putative receptor.
[0184] In another assay for antagonists, mammalian cells or a
membrane preparation expressing the receptor would be incubated
with labeled PRO polypeptide in the presence of the candidate
compound. The ability of the compound to enhance or block this
interaction could then be measured.
[0185] More specific examples of potential antagonists include an
oligonucleotide that binds to the fusions of immunoglobulin with
PRO polypeptide, and, in particular, antibodies including, without
limitation, poly- and monoclonal antibodies and antibody fragments,
single-chain antibodies, anti-idiotypic antibodies, and chimeric or
humanized versions of such antibodies or fragments, as well as
human antibodies and antibody fragments. Alternatively, a potential
antagonist may be a closely related protein, for example, a mutated
form of the PRO polypeptide that recognizes the receptor but
imparts no effect, thereby competitively inhibiting the action of
the PRO polypeptide.
[0186] Another potential PRO polypeptide antagonist is an antisense
RNA or DNA construct prepared using antisense technology, where,
e.g., an antisense RNA or DNA molecule acts to block directly the
translation of mRNA by hybridizing to targeted mRNA and preventing
protein translation. Antisense technology can be used to control
gene expression through triple-helix formation or antisense DNA or
RNA, both of which methods are based on binding of a polynucleotide
to DNA or RNA. For example, the 5' coding portion of the
polynucleotide sequence, which encodes the mature PRO polypeptides
herein, is used to design an antisense RNA oligonucleotide of from
about 10 to 40 base pairs in length. A DNA oligonucleotide is
designed to be complementary to a region of the gene involved in
transcription (triple helix--see Lee et al., Nucl. Acids Res.,
6:3073 (1979); Cooney et al., Science, 241: 456 (1988); Dervan et
al., Science, 251:1360 (1991)), thereby preventing transcription
and the production of the PRO polypeptide. The antisense RNA
oligonucleotide hybridizes to the mRNA in vivo and blocks
translation of the mRNA molecule into the PRO polypeptide
(antisense--Okano, Neurochem., 56:560 (1991); Oligodeoxynucleotides
as Antisense Inhibitors of Gene Expression (CRC Press: Boca Raton,
Fla., 1988). The oligonucleotides described above can also be
delivered to cells such that the antisense RNA or DNA may be
expressed in vivo to inhibit production of the PRO polypeptide.
When antisense DNA is used, oligodeoxyribonucleotides derived from
the translation-initiation site, e.g., between about -10 and +10
positions of the target gene nucleotide sequence, are
preferred.
[0187] Potential antagonists include small molecules that bind to
the active site, the receptor binding site, or growth factor or
other relevant binding site of the PRO polypeptide, thereby
blocking the normal biological activity of the PRO polypeptide.
Examples of small molecules include, but are not limited to, small
peptides or peptide-like molecules, preferably soluble peptides,
and synthetic non-peptidyl organic or inorganic compounds.
[0188] Ribozymes are enzymatic RNA molecules capable of catalyzing
the specific cleavage of RNA. Ribozymes act by sequence-specific
hybridization to the complementary target RNA, followed by
endonucleolytic cleavage. Specific ribozyme cleavage sites within a
potential RNA target can be identified by known techniques. For
further details see, e.g., Rossi, Current Biology, 4:469-471
(1994), and PCT publication No. WO 97/33551 (published Sep. 18,
1997).
[0189] Nucleic acid molecules in triple-helix formation used to
inhibit transcription should be single-stranded and composed of
deoxynucleotides. The base composition of these oligonucleotides is
designed such that it promotes triple-helix formation via Hoogsteen
base-pairing rules, which generally require sizeable stretches of
purines or pyrimidines on one strand of a duplex. For further
details see, e.g., PCT publication No. WO 97/33551, supra.
[0190] These small molecules can be identified by any one or more
of the screening assays discussed hereinabove and/or by any other
screening techniques well known for those skilled in the art.
[0191] Diagnostic and therapeutic uses of the herein disclosed
molecules may also be based upon the positive functional assay hits
disclosed and described below.
[0192] F. Anti-PRO Antibodies
[0193] The present invention further provides anti-PRO antibodies.
Exemplary antibodies include polyclonal, monoclonal, humanized,
bispecific, and heteroconjugate antibodies.
[0194] 1. Polyclonal Antibodies
[0195] The anti-PRO antibodies may comprise polyclonal antibodies.
Methods of preparing polyclonal antibodies are known to the skilled
artisan. Polyclonal antibodies can be raised in a mammal, for
example, by one or more injections of an immunizing agent and, if
desired, an adjuvant. Typically, the immunizing agent and/or
adjuvant will be injected in the mammal by multiple subcutaneous or
intraperitoneal injections. The immunizing agent may include the
PRO polypeptide or a fusion protein thereof. It may be useful to
conjugate the immunizing agent to a protein known to be immunogenic
in the mammal being immunized. Examples of such immunogenic
proteins include but are not limited to keyhole limpet hemocyanin,
serum albumin, bovine thyroglobulin, and soybean trypsin inhibitor.
Examples of adjuvants which may be employed include Freund's
complete adjuvant and MPL-TDM adjuvant (monophosphoryl Lipid A,
synthetic trehalose dicorynomycolate). The immunization protocol
may be selected by one skilled in the art without undue
experimentation.
[0196] 2. Monoclonal Antibodies
[0197] The anti-PRO antibodies may, alternatively, be monoclonal
antibodies. Monoclonal antibodies may be prepared using hybridoma
methods, such as those described by Kohler and Milstein, Nature,
256:495 (1975). In a hybridoma method, a mouse, hamster, or other
appropriate host animal, is typically immunized with an immunizing
agent to elicit lymphocytes that produce or are capable of
producing antibodies that will specifically bind to the immunizing
agent. Alternatively, the lymphocytes may be immunized in
vitro.
[0198] The immunizing agent will typically include the PRO
polypeptide or a fusion protein thereof. Generally, either
peripheral blood lymphocytes ("PBLs") are used if cells of human
origin are desired, or spleen cells or lymph node cells are used if
non-human mammalian sources are desired. The lymphocytes are then
fused with an immortalized cell line using a suitable fusing agent,
such as polyethylene glycol, to form a hybridoma cell [Goding,
Monoclonal Antibodies: Principles and Practice, Academic Press,
(1986) pp. 59-103]. Immortalized cell lines are usually transformed
mammalian cells, particularly myeloma cells of rodent, bovine and
human origin. Usually, rat or mouse myeloma cell lines are
employed. The hybridoma cells may be cultured in a suitable culture
medium that preferably contains one or more substances that inhibit
the growth or survival of the unfused, immortalized cells. For
example, if the parental cells lack the enzyme hypoxanthine guanine
phosphoribosyl transferase (HGPRT or HPRT), the culture medium for
the hybridomas typically will include hypoxanthine, aminopterin,
and thymidine ("HAT medium"), which substances prevent the growth
of HGPRT-deficient cells.
[0199] Preferred immortalized cell lines are those that fuse
efficiently, support stable high level expression of antibody by
the selected antibody-producing cells, and are sensitive to a
medium such as HAT medium. More preferred immortalized cell lines
are murine myeloma lines, which can be obtained, for instance, from
the Salk Institute Cell Distribution Center, San Diego, Calif. and
the American Type Culture Collection, Manassas, Va. Human myeloma
and mouse-human heteromyeloma cell lines also have been described
for the production of human monoclonal antibodies [Kozbor, J.
Immunol., 133:3001 (1984); Brodeur et al., Monoclonal Antibody
Production Techniques and Applications, Marcel Dekker, Inc., New
York, (1987) pp. 51-63].
[0200] The culture medium in which the hybridoma cells are cultured
can then be assayed for the presence of monoclonal antibodies
directed against PRO. Preferably, the binding specificity of
monoclonal antibodies produced by the hybridoma cells is determined
by immunoprecipitation or by an in vitro binding assay, such as
radioimmunoassay (RIA) or enzyme-linked immunoabsorbent assay
(ELISA). Such techniques and assays are known in the art. The
binding affinity of the monoclonal antibody can, for example, be
determined by the Scatchard analysis of Munson and Pollard, Anal.
Biochem., 107:220 (1980).
[0201] After the desired hybridoma cells are identified, the clones
may be subcloned by limiting dilution procedures and grown by
standard methods [Goding, supra]. Suitable culture media for this
purpose include, for example, Dulbecco's Modified Eagle's Medium
and RPMI-1640 medium. Alternatively, the hybridoma cells may be
grown in vivo as ascites in a mammal.
[0202] The monoclonal antibodies secreted by the subclones may be
isolated or purified from the culture medium or ascites fluid by
conventional immunoglobulin purification procedures such as, for
example, protein A-Sepharose, hydroxylapatite chromatography, gel
electrophoresis, dialysis, or affinity chromatography.
[0203] The monoclonal antibodies may also be made by recombinant
DNA methods, such as those described in U.S. Pat. No. 4,816,567.
DNA encoding the monoclonal antibodies of the invention can be
readily isolated and sequenced using conventional procedures (e.g.,
by using oligonucleotide probes that are capable of binding
specifically to genes encoding the heavy and light chains of murine
antibodies). The hybridoma cells of the invention serve as a
preferred source of such DNA. Once isolated, the DNA may be placed
into expression vectors, which are then transfected into host cells
such as simian COS cells, Chinese hamster ovary (CHO) cells, or
myeloma cells that do not otherwise produce immunoglobulin protein,
to obtain the synthesis of monoclonal antibodies in the recombinant
host cells. The DNA also may be modified, for example, by
substituting the coding sequence for human heavy and light chain
constant domains in place of the homologous murine sequences [U.S.
Pat. No. 4,816,567; Morrison et al., supra] or by covalently
joining to the immunoglobulin coding sequence all or part of the
coding sequence for a non-immunoglobulin polypeptide. Such a
non-immunoglobulin polypeptide can be substituted for the constant
domains of an antibody of the invention, or can be substituted for
the variable domains of one antigen-combining site of an antibody
of the invention to create a chimeric bivalent antibody.
[0204] The antibodies may be monovalent antibodies. Methods for
preparing monovalent antibodies are well known in the art. For
example, one method involves recombinant expression of
immunoglobulin light chain and modified heavy chain. The heavy
chain is truncated generally at any point in the Fc region so as to
prevent heavy chain crosslinking. Alternatively, the relevant
cysteine residues are substituted with another amino acid residue
or are deleted so as to prevent crosslinking.
[0205] In vitro methods are also suitable for preparing monovalent
antibodies. Digestion of antibodies to produce fragments thereof,
particularly, Fab fragments, can be accomplished using routine
techniques known in the art.
[0206] 3. Human and Humanized Antibodies
[0207] The anti-PRO antibodies of the invention may further
comprise humanized antibodies or human antibodies. Humanized forms
of non-human (e.g., murine) antibodies are chimeric
immunoglobulins, immunoglobulin chains or fragments thereof (such
as Fv, Fab, Fab', F(ab').sub.2 or other antigen-binding
subsequences of antibodies) which contain minimal sequence derived
from non-human immunoglobulin. Humanized antibodies include human
immunoglobulins (recipient antibody) in which residues from a
complementary determining region (CDR) of the recipient are
replaced by residues from a CDR of a non-human species (donor
antibody) such as mouse, rat or rabbit having the desired
specificity, affinity and capacity. In some instances, Fv framework
residues of the human immunoglobulin are replaced by corresponding
non-human residues. Humanized antibodies may also comprise residues
which are found neither in the recipient antibody nor in the
imported CDR or framework sequences. In general, the humanized
antibody will comprise substantially all of at least one, and
typically two, variable domains, in which all or substantially all
of the CDR regions correspond to those of a non-human
immunoglobulin and all or substantially all of the FR regions are
those of a human immunoglobulin consensus sequence. The humanized
antibody optimally also will comprise at least a portion of an
immunoglobulin constant region (Fc), typically that of a human
immunoglobulin [Jones et al., Nature 321:522-525 (1986); Riechmann
et al., Nature, 332:323-329 (1988); and Presta, Curr. Op. Struct.
Biol., 2:593-596 (1992)].
[0208] Methods for humanizing non-human antibodies are well known
in the art. Generally, a humanized antibody has one or more amino
acid residues introduced into it from a source which is non-human.
These non-human amino acid residues are often referred to as
"import" residues, which are typically taken from an "import"
variable domain. Humanization can be essentially performed
following the method of Winter and co-workers [Jones et al., Nature
321:522-525 (1986); Riechmann et al., Nature 332:323-327 (1988);
Verhoeyen et al., Science 239:1534-1536 (1988)], by substituting
rodent CDRs or CDR sequences for the corresponding sequences of a
human antibody. Accordingly, such "humanized" antibodies are
chimeric antibodies (U.S. Pat. No. 4,816,567), wherein
substantially less than an intact human variable domain has been
substituted by the corresponding sequence from a non-human species.
In practice, humanized antibodies are typically human antibodies in
which some CDR residues and possibly some FR residues are
substituted by residues from analogous sites in rodent
antibodies.
[0209] Human antibodies can also be produced using various
techniques known in the art, including phage display libraries
[Hoogenboom and Winter, J. Mol. Biol., 227:381 (1991); Marks et
al., J. Mol. Biol., 222:581 (1991)]. The techniques of Cole et al.
and Boerner et al. are also available for the preparation of human
monoclonal antibodies (Cole et al., Monoclonal Antibodies and
Cancer Therapy, Alan R. Liss, p. 77 (1985) and Boerner et al., J.
Immunol., 147(1):86-95 (1991)]. Similarly, human antibodies can be
made by introducing of human immunoglobulin loci into transgenic
animals, e.g., mice in which the endogenous immunoglobulin genes
have been partially or completely inactivated. Upon challenge,
human antibody production is observed, which closely resembles that
seen in humans in all respects, including gene rearrangement,
assembly, and antibody repertoire. This approach is described, for
example, in U.S. Pat. Nos. 5,545,807; 5,545,806; 5,569,825;
5,625,126; 5,633,425; 5,661,016, and in the following scientific
publications: Marks et al., Bio/Technology 10, 779-783 (1992);
Lonberg et al., Nature 368 856-859 (1994); Morrison, Nature 368,
812-13 (1994); Fishwild et al., Nature Biotechnology 14, 845-51
(1996); Neuberger, Nature Biotechnology 14, 826 (1996); Lonberg and
Huszar, Intern. Rev. Immunol. 13 65-93 (1995).
[0210] The antibodies may also be affinity matured using known
selection and/or mutagenesis methods as described above. Preferred
affinity matured antibodies have an affinity which is five times,
more preferably 10 times, even more preferably 20 or 30 times
greater than the starting antibody (generally murine, humanized or
human) from which the matured antibody is prepared.
[0211] 4. Bispecific Antibodies
[0212] Bispecific antibodies are monoclonal, preferably human or
humanized, antibodies that have binding specificities for at least
two different antigens. In the present case, one of the binding
specificities is for the PRO, the other one is for any other
antigen, and preferably for a cell-surface protein or receptor or
receptor subunit.
[0213] Methods for making bispecific antibodies are known in the
art. Traditionally, the recombinant production of bispecific
antibodies is based on the co-expression of two immunoglobulin
heavy-chain/light-chain pairs, where the two heavy chains have
different specificities [Milstein and Cuello, Nature, 305:537-539
(1983)]. Because of the random assortment of immunoglobulin heavy
and light chains, these hybridomas (quadromas) produce a potential
mixture of ten different antibody molecules, of which only one has
the correct bispecific structure. The purification of the correct
molecule is usually accomplished by affinity chromatography steps.
Similar procedures are disclosed in WO 93/08829, published 13 May
1993, and in Traunecker et al., EMBO J. 10:3655-3659 (1991).
[0214] Antibody variable domains with the desired binding
specificities (antibody-antigen combining sites) can be fused to
immunoglobulin constant domain sequences. The fusion preferably is
with an immunoglobulin heavy-chain constant domain, comprising at
least part of the hinge, CH2, and CH3 regions. It is preferred to
have the first heavy-chain constant region (CH1) containing the
site necessary for light-chain binding present in at least one of
the fusions. DNAs encoding the immunoglobulin heavy-chain fusions
and, if desired, the immunoglobulin light chain, are inserted into
separate expression vectors, and are co-transfected into a suitable
host organism. For further details of generating bispecific
antibodies see, for example, Suresh et al., Methods in Enzymology,
121:210 (1986).
[0215] According to another approach described in WO 96/27011, the
interface between a pair of antibody molecules can be engineered to
maximize the percentage of heterodimers which are recovered from
recombinant cell culture. The preferred interface comprises at
least a part of the CH3 region of an antibody constant domain. In
this method, one or more small amino acid side chains from the
interface of the first antibody molecule are replaced with larger
side chains (e.g. tyrosine or tryptophan). Compensatory "cavities"
of identical or similar size to the large side chain(s) are created
on the interface of the second antibody molecule by replacing large
amino acid side chains with smaller ones (e.g. alanine or
threonine). This provides a mechanism for increasing the yield of
the heterodimer over other unwanted end-products such as
homodimers.
[0216] Bispecific antibodies can be prepared as full length
antibodies or antibody fragments (e.g. F(ab').sub.2 bispecific
antibodies). Techniques for generating bispecific antibodies from
antibody fragments have been described in the literature. For
example, bispecific antibodies can be prepared can be prepared
using chemical linkage. Brennan et al., Science 229:81 (1985)
describe a procedure wherein intact antibodies are proteolytically
cleaved to generate F(ab').sub.2 fragments. These fragments are
reduced in the presence of the dithiol complexing agent sodium
arsenite to stabilize vicinal dithiols and prevent intermolecular
disulfide formation. The Fab' fragments generated are then
converted to thionitrobenzoate (TNB) derivatives. One of the
Fab'-TNB derivatives is then reconverted to the Fab'-thiol by
reduction with mercaptoethylamine and is mixed with an equimolar
amount of the other Fab'-TNB derivative to form the bispecific
antibody. The bispecific antibodies produced can be used as agents
for the selective immobilization of enzymes.
[0217] Fab' fragments may be directly recovered from E. coli and
chemically coupled to form bispecific antibodies. Shalaby et al.,
J. Exp. Med. 175:217-225 (1992) describe the production of a fully
humanized bispecific antibody F(ab').sub.2 molecule. Each Fab'
fragment was separately secreted from E. coli and subjected to
directed chemical coupling in vitro to form the bispecific
antibody. The bispecific antibody thus formed was able to bind to
cells overexpressing the ErbB2 receptor and normal human T cells,
as well as trigger the lytic activity of human cytotoxic
lymphocytes against human breast tumor targets.
[0218] Various technique for making and isolating bispecific
antibody fragments directly from recombinant cell culture have also
been described. For example, bispecific antibodies have been
produced using leucine zippers. Kostelny et al., J. Immunol.
148(5):1547-1553 (1992). The leucine zipper peptides from the Fos
and Jun proteins were linked to the Fab' portions of two different
antibodies by gene fusion. The antibody homodimers were reduced at
the hinge region to form monomers and then re-oxidized to form the
antibody heterodimers. This method can also be utilized for the
production of antibody homodimers. The "diabody" technology
described by Hollinger et al., Proc. Natl. Acad. Sci. USA
90:6444-6448 (1993) has provided an alternative mechanism for
making bispecific antibody fragments. The fragments comprise a
heavy-chain variable domain (V.sub.H) connected to a light-chain
variable domain (V.sub.L) by a linker which is too short to allow
pairing between the two domains on the same chain. Accordingly, the
V.sub.H and V.sub.L domains of one fragment are forced to pair with
the complementary V.sub.L and V.sub.H domains of another fragment,
thereby forming two antigen-binding sites. Another strategy for
making bispecific antibody fragments by the use of single-chain Fv
(sFv) dimers has also been reported. See, Gruber et al., J.
Immunol. 152:5368 (1994).
[0219] Antibodies with more than two valencies are contemplated.
For example, trispecific antibodies can be prepared. Tutt et al.,
J. Immunol. 147:60 (1991).
[0220] Exemplary bispecific antibodies may bind to two different
epitopes on a given PRO polypeptide herein. Alternatively, an
anti-PRO polypeptide arm may be combined with an arm which binds to
a triggering molecule on a leukocyte such as a T-cell receptor
molecule (e.g. CD2, CD3, CD28, or B7), or Fc receptors for IgG
(Fc.gamma.R), such as Fc.gamma.RI (CD64), Fc.gamma.RII (CD32) and
Fc.gamma.RIII (CD16) so as to focus cellular defense mechanisms to
the cell expressing the particular PRO polypeptide. Bispecific
antibodies may also be used to localize cytotoxic agents to cells
which express a particular PRO polypeptide. These antibodies
possess a PRO-binding arm and an arm which binds a cytotoxic agent
or a radionuclide chelator, such as EOTUBE, DPTA, DOTA, or TETA.
Another bispecific antibody of interest binds the PRO polypeptide
and further binds tissue factor (TF).
[0221] 5. Heteroconjugate Antibodies
[0222] Heteroconjugate antibodies are also within the scope of the
present invention. Heteroconjugate antibodies are composed of two
covalently joined antibodies. Such antibodies have, for example,
been proposed to target immune system cells to unwanted cells [U.S.
Pat. No. 4,676,980], and for treatment of HIV infection [WO
91/00360; WO 92/200373; EP 03089]. It is contemplated that the
antibodies may be prepared in vitro using known methods in
synthetic protein chemistry, including those involving crosslinking
agents. For example, immunotoxins may be constructed using a
disulfide exchange reaction or by forming a thioether bond.
Examples of suitable reagents for this purpose include
iminothiolate and methyl-4-mercaptobutyrimidate and those
disclosed, for example, in U.S. Pat. No. 4,676,980.
[0223] 6. Effector Function Engineering
[0224] It may be desirable to modify the antibody of the invention
with respect to effector function, so as to enhance, e.g., the
effectiveness of the antibody in treating cancer. For example,
cysteine residue(s) may be introduced into the Fc region, thereby
allowing interchain disulfide bond formation in this region. The
homodimeric antibody thus generated may have improved
internalization capability and/or increased complement-mediated
cell killing and antibody-dependent cellular cytotoxicity (ADCC).
See Caron et al., J. Exp Med., 176: 1191-1195 (1992) and Shopes, J.
Immunol., 148: 2918-2922 (1992). Homodimeric antibodies with
enhanced anti-tumor activity may also be prepared using
heterobifunctional cross-linkers as described in Wolff et al.
Cancer Research, 53: 2560-2565 (1993). Alternatively, an antibody
can be engineered that has dual Fe regions and may thereby have
enhanced complement lysis and ADCC capabilities. See Stevenson et
al., Anti-Cancer Drug Design, 3: 219-230 (1989).
[0225] 7. Immunoconjugates
[0226] The invention also pertains to immunoconjugates comprising
an antibody conjugated to a cytotoxic agent such as a
chemotherapeutic agent, toxin (e.g., an enzymatically active toxin
of bacterial, fungal, plant, or animal origin, or fragments
thereof), or a radioactive isotope (i.e., a radioconjugate).
[0227] Chemotherapeutic agents useful in the generation of such
immunoconjugates have been described above. Enzymatically active
toxins and fragments thereof that can be used include diphtheria A
chain, nonbinding active fragments of diphtheria toxin, exotoxin A
chain (from Pseudomonas aeruginosa), ricin A chain, abrin A chain,
modeccin A chain, alpha-sarcin, Aleurites fordii proteins, dianthin
proteins, Phytolaca americana proteins (PAPI, PAPII, and PAP-S),
momordica charantia inhibitor, curcin, crotin, sapaonaria
officinalis inhibitor, gelonin, mitogellin, restrictocin,
phenomycin, enomycin, and the tricothecenes. A variety of
radionuclides are available for the production of radioconjugated
antibodies. Examples include .sup.221Bi, .sup.131I, .sup.131In,
.sup.90Y, and .sup.186Re. Conjugates of the antibody and cytotoxic
agent are made using a variety of bifunctional protein-coupling
agents such as N-succinimidyl-3-(2-pyridyldithiol)propionate
(SPDP), iminothiolane (IT), bifunctional derivatives of imidoesters
(such as dimethyl adipimidate HCL), active esters (such as
disuccinimidyl suberate), aldehydes (such as glutareldehyde),
bis-azido compounds (such as bis(p-azidobenzoyl)hexanediamine),
bis-diazonium derivatives (such as
bis-(p-diazoniumbenzoyl)-ethylenediamine), diisocyanates (such as
tolyene 2,6-diisocyanate), and bis-active fluorine compounds (such
as 1,5-difluoro-2,4-dinitrobenzene). For example, a ricin
immunotoxin can be prepared as described in Vitetta et al.,
Science, 238: 1098 (1987). Carbon-14-labeled
1-isothiocyanatobenzyl-3-methyldiethylene triaminepentaacetic acid
(MX-DTPA) is an exemplary chelating agent for conjugation of
radionucleotide to the antibody. See WO94/11026.
[0228] In another embodiment, the antibody may be conjugated to a
"receptor" (such streptavidin) for utilization in tumor
pretargeting wherein the antibody-receptor conjugate is
administered to the patient, followed by removal of unbound
conjugate from the circulation using a clearing agent and then
administration of a "ligand" (e.g., avidin) that is conjugated to a
cytotoxic agent (e.g., a radionucleotide).
[0229] 8. Immunoliposomes
[0230] The antibodies disclosed herein may also be formulated as
immunoliposomes. Liposomes containing the antibody are prepared by
methods known in the art, such as described in Epstein et al.,
Proc. Natl. Acad. Sci. USA, 82: 3688 (1985); Hwang et al, Proc.
Natl. Acad. Sci. USA, 77:4030 (1980); and U.S. Pat. Nos. 4,485,045
and 4,544,545. Liposomes with enhanced circulation time are
disclosed in U.S. Pat. No. 5,013,556.
[0231] Particularly useful liposomes can be generated by the
reverse-phase evaporation method with a lipid composition
comprising phosphatidylcholine, cholesterol, and PEG-derivatized
phosphatidylethanolamine (PEG-PE). Liposomes are extruded through
filters of defined pore size to yield liposomes with the desired
diameter. Fab' fragments of the antibody of the present invention
can be conjugated to the liposomes as described in Martin et al.,
J. Biol. Chem., 257: 286-288 (1982) via a disulfide-interchange
reaction. A chemotherapeutic agent (such as Doxorubicin) is
optionally contained within the liposome. See Gabizon et al., J.
National Cancer Inst., 81(19): 1484 (1989).
[0232] 9. Pharmaceutical Compositions of Antibodies
[0233] Antibodies specifically binding a PRO polypeptide identified
herein, as well as other molecules identified by the screening
assays disclosed hereinbefore, can be administered for the
treatment of various disorders in the form of pharmaceutical
compositions.
[0234] If the PRO polypeptide is intracellular and whole antibodies
are used as inhibitors, internalizing antibodies are preferred.
However, lipofections or liposomes can also be used to deliver the
antibody, or an antibody fragment, into cells. Where antibody
fragments are used, the smallest inhibitory fragment that
specifically binds to the binding domain of the target protein is
preferred. For example, based upon the variable-region sequences of
an antibody, peptide molecules can be designed that retain the
ability to bind the target protein sequence. Such peptides can be
synthesized chemically and/or produced by recombinant DNA
technology. See, e.g. Marasco et al., Proc. Natl. Acad. Sci. USA,
90: 7889-7893 (1993). The formulation herein may also contain more
than one active compound as necessary for the particular indication
being treated, preferably those with complementary activities that
do not adversely affect each other. Alternatively, or in addition,
the composition may comprise an agent that enhances its function,
such as, for example, a cytotoxic agent, cytokine, chemotherapeutic
agent, or growth-inhibitory agent. Such molecules are suitably
present in combination in amounts that are effective for the
purpose intended.
[0235] The active ingredients may also be entrapped in
microcapsules prepared, for example, by coacervation techniques or
by interfacial polymerization, for example, hydroxymethylcellulose
or gelatin-microcapsules and poly-(methylmethacylate)
microcapsules, respectively, in colloidal drug delivery systems
(for example, liposomes, albumin microspheres, microemulsions,
nano-particles, and nanocapsules) or in macroemulsions. Such
techniques are disclosed in Remington's Pharmaceutical Sciences,
supra.
[0236] The formulations to be used for in vivo administration must
be sterile. This is readily accomplished by filtration through
sterile filtration membranes.
[0237] Sustained-release preparations may be prepared. Suitable
examples of sustained-release preparations include semipermeable
matrices of solid hydrophobic polymers containing the antibody,
which matrices are in the form of shaped articles, e.g., films, or
microcapsules. Examples of sustained-release matrices include
polyesters, hydrogels (for example,
poly(2-hydroxyethyl-methacrylate), or poly(vinylalcohol)),
polylactides (U.S. Pat. No. 3,773,919), copolymers of L-glutamic
acid and y ethyl-L-glutamate, non-degradable ethylene-vinyl
acetate, degradable lactic acid-glycolic acid copolymers such as
the LUPRON DEPOT.TM. (injectable microspheres composed of lactic
acid-glycolic acid copolymer and leuprolide acetate), and
poly-D-(-)-3-hydroxybutyric acid. While polymers such as
ethylene-vinyl acetate and lactic acid-glycolic acid enable release
of molecules for over 100 days, certain hydrogels release proteins
for shorter time periods. When encapsulated antibodies remain in
the body for a long time, they may denature or aggregate as a
result of exposure to moisture at 37.degree. C., resulting in a
loss of biological activity and possible changes in immunogenicity.
Rational strategies can be devised for stabilization depending on
the mechanism involved. For example, if the aggregation mechanism
is discovered to be intermolecular S--S bond formation through
thio-disulfide interchange, stabilization may be achieved by
modifying sulfhydryl residues, lyophilizing from acidic solutions,
controlling moisture content, using appropriate additives, and
developing specific polymer matrix compositions.
[0238] G. Uses for Anti-PRO Antibodies
[0239] The anti-PRO antibodies of the invention have various
utilities. For example, anti-PRO antibodies may be used in
diagnostic assays for PRO, e.g., detecting its expression (and in
some cases, differential expression) in specific cells, tissues, or
serum. Various diagnostic assay techniques known in the art may be
used, such as competitive binding assays, direct or indirect
sandwich assays and immunoprecipitation assays conducted in either
heterogeneous or homogeneous phases [Zola, Monoclonal Antibodies: A
Manual of Techniques, CRC Press, Inc. (1987) pp. 147-158]. The
antibodies used in the diagnostic assays can be labeled with a
detectable moiety. The detectable moiety should be capable of
producing, either directly or indirectly, a detectable signal. For
example, the detectable moiety may be a radioisotope, such as
.sup.3H, .sup.14C, .sup.32P, .sup.35S, or .sup.125I, a fluorescent
or chemiluminescent compound, such as fluorescein isothiocyanate,
rhodamine, or luciferin, or an enzyme, such as alkaline
phosphatase, beta-galactosidase or horseradish peroxidase. Any
method known in the art for conjugating the antibody to the
detectable moiety may be employed, including those methods
described by Hunter et al., Nature 144:945 (1962); David et al.,
Biochemistry, 13:1014 (1974); Pain et al., J. Immunol. Meth.,
40:219 (1981); and Nygren, J. Histochem. and Cytochem., 30:407
(1982).
[0240] Anti-PRO antibodies also are useful for the affinity
purification of PRO from recombinant cell culture or natural
sources. In this process, the antibodies against PRO are
immobilized on a suitable support, such a Sephadex resin or filter
paper, using methods well known in the art. The immobilized
antibody then is contacted with a sample containing the PRO to be
purified, and thereafter the support is washed with a suitable
solvent that will remove substantially all the material in the
sample except the PRO, which is bound to the immobilized antibody.
Finally, the support is washed with another suitable solvent that
will release the PRO from the antibody.
[0241] The following examples are offered for illustrative purposes
only, and are not intended to limit the scope of the present
invention in any way.
[0242] All patent and literature references cited in the present
specification are hereby incorporated by reference in their
entirety.
EXAMPLES
[0243] Commercially available reagents referred to in the examples
were used according to manufacturer's instructions unless otherwise
indicated. The source of those cells identified in the following
examples, and throughout the specification, by ATCC accession
numbers is the American Type Culture Collection, Manassas, Va.
Example 1
Extracellular Domain Homology Screening to Identify Novel
Polypeptides and cDNA Encoding Therefor
[0244] The extracellular domain (ECD) sequences (including the
secretion signal sequence, if any) from about 950 known secreted
proteins from the Swiss-Prot public database were used to search
EST databases. The EST databases included public databases (e.g.,
Dayhoff, GenBank), and proprietary databases (e.g. LIFESEQ.TM.,
Incyte Pharmaceuticals, Palo Alto, Calif.). The search was
performed using the computer program BLAST or BLAST-2 (Altschul et
al., Methods in Enzymology, 266:460-480 (1996)) as a comparison of
the ECD protein sequences to a 6 frame translation of the EST
sequences. Those comparisons with a BLAST score of 70 (or in some
cases 90) or greater that did not encode known proteins were
clustered and assembled into consensus DNA sequences with the
program "phrap" (Phil Green, University of Washington, Seattle,
Wash.).
[0245] Using this extracellular domain homology screen, consensus
DNA sequences were assembled relative to the other identified EST
sequences using phrap. In addition, the consensus DNA sequences
obtained were often (but not always) extended using repeated cycles
of BLAST or BLAST-2 and phrap to extend the consensus sequence as
far as possible using the sources of EST sequences discussed
above.
[0246] Based upon the consensus sequences obtained as described
above, oligonucleotides were then synthesized and used to identify
by PCR a cDNA library that contained the sequence of interest and
for use as probes to isolate a clone of the full-length coding
sequence for a PRO polypeptide. Forward and reverse PCR primers
generally range from 20 to 30 nucleotides and are often designed to
give a PCR product of about 100-1000 bp in length. The probe
sequences are typically 40-55 bp in length. In some cases,
additional oligonucleotides are synthesized when the consensus
sequence is greater than about 1-1.5 kbp. In order to screen
several libraries for a full-length clone, DNA from the libraries
was screened by PCR amplification, as per Ausubel et al., Current
Protocols in Molecular Biology, with the PCR primer pair. A
positive library was then used to isolate clones encoding the gene
of interest using the probe oligonucleotide and one of the primer
pairs.
[0247] The cDNA libraries used to isolate the cDNA clones were
constructed by standard methods using commercially available
reagents such as those from Invitrogen, San Diego, Calif. The cDNA
was primed with oligo dT containing a NotI site, linked with blunt
to SalI hemikinased adaptors, cleaved with NotI, sized
appropriately by gel electrophoresis, and cloned in a defined
orientation into a suitable cloning vector (such as pRKB or pRKD;
pRK5B is a precursor of pRK5D that does not contain the SfiI site;
see, Holmes et al., Science, 253:1278-1280 (1991)) in the unique
XhoI and NotI sites.
Example 2
Isolation of cDNA Clones by Amylase Screening
[0248] 1. Preparation of Oligo dT Primed cDNA Library
[0249] mRNA was isolated from a human tissue of interest using
reagents and protocols from Invitrogen, San Diego, Calif. (Fast
Track 2). This RNA was used to generate an oligo dT primed cDNA
library in the vector pRK5D using reagents and protocols from Life
Technologies, Gaithersburg, Md. (Super Script Plasmid System). In
this procedure, the double stranded cDNA was sized to greater than
1000 bp and the SalI/NotI linkered cDNA was cloned into XhoI/NotI
cleaved vector. pRK5D is a cloning vector that has an sp6
transcription initiation site followed by an SfiI restriction
enzyme site preceding the XhoI/NotI cDNA cloning sites.
[0250] 2. Preparation of Random Primed cDNA Library
[0251] A secondary cDNA library was generated in order to
preferentially represent the 5' ends of the primary cDNA clones.
Sp6 RNA was generated from the primary library (described above),
and this RNA was used to generate a random primed cDNA library in
the vector pSST-AMY.0 using reagents and protocols from Life
Technologies (Super Script Plasmid System, referenced above). In
this procedure the double stranded cDNA was sized to 500-1000 bp,
linkered with blunt to NotI adaptors, cleaved with SfiI, and cloned
into SfiI/NotI cleaved vector. pSST-AMY.0 is a cloning vector that
has a yeast alcohol dehydrogenase promoter preceding the cDNA
cloning sites and the mouse amylase sequence (the mature sequence
without the secretion signal) followed by the yeast alcohol
dehydrogenase terminator, after the cloning sites. Thus, cDNAs
cloned into this vector that are fused in frame with amylase
sequence will lead to the secretion of amylase from appropriately
transfected yeast colonies.
[0252] 3. Transformation and Detection
[0253] DNA from the library described in paragraph 2 above was
chilled on ice to which was added electrocompetent DH10B bacteria
(Life Technologies, 20 ml). The bacteria and vector mixture was
then electroporated as recommended by the manufacturer.
Subsequently, SOC media (Life Technologies, 1 ml) was added and the
mixture was incubated at 37.degree. C. for 30 minutes. The
transformants were then plated onto 20 standard 150 mm LB plates
containing ampicillin and incubated for 16 hours (37.degree. C.).
Positive colonies were scraped off the plates and the DNA was
isolated from the bacterial pellet using standard protocols, e.g.
CsCl-gradient. The purified DNA was then carried on to the yeast
protocols below.
[0254] The yeast methods were divided into three categories: (1)
Transformation of yeast with the plasmid/cDNA combined vector; (2)
Detection and isolation of yeast clones secreting amylase; and (3)
PCR amplification of the insert directly from the yeast colony and
purification of the DNA for sequencing and further analysis.
[0255] The yeast strain used was HD56-5A (ATCC-90785). This strain
has the following genotype: MAT alpha, ura3-52, leu2-3, leu2-112,
his3-11, his3-15, MAL.sup.+, SUC.sup.+, GAL.sup.+. Preferably,
yeast mutants can be employed that have deficient
post-translational pathways. Such mutants may have translocation
deficient alleles in sec71, sec72, sec62, with truncated sec71
being most preferred. Alternatively, antagonists (including
antisense nucleotides and/or ligands) which interfere with the
normal operation of these genes, other proteins implicated in this
post translation pathway (e.g., SEC61p, SEC72p, SEC62p, SEC63p,
TDJ1p or SSA1p-4p) or the complex formation of these proteins may
also be preferably employed in combination with the
amylase-expressing yeast.
[0256] Transformation was performed based on the protocol outlined
by Gietz et al., Nucl. Acid. Res., 20:1425 (1992). Transformed
cells were then inoculated from agar into YEPD complex media broth
(100 ml) and grown overnight at 30.degree. C. The YEPD broth was
prepared as described in Kaiser et al., Methods in Yeast Genetics,
Cold Spring Harbor Press, Cold Spring Harbor, N.Y., p. 207 (1994).
The overnight culture was then diluted to about 2.times.10.sup.6
cells/ml (approx. OD.sub.600=0.1) into fresh YEPD broth (500 ml)
and regrown to 1.times.10.sup.7 cells/ml (approx.
OD.sub.600=0.4-0.5).
[0257] The cells were then harvested and prepared for
transformation by transfer into GS3 rotor bottles in a Sorval GS3
rotor at 5,000 rpm for 5 minutes, the supernatant discarded, and
then resuspended into sterile water, and centrifuged again in 50 ml
falcon tubes at 3,500 rpm in a Beckman GS-6KR centrifuge. The
supernatant was discarded and the cells were subsequently washed
with LiAc/TE (10 ml, 10 mM Tris-HCl, 1 mM EDTA pH 7.5, 100 mM
Li.sub.2OOCCH.sub.3), and resuspended into LiAc/TE (2.5 ml).
[0258] Transformation took place by mixing the prepared cells (100
.mu.l) with freshly denatured single stranded salmon testes DNA
(Lofstrand Labs, Gaithersburg, Md.) and transforming DNA (1 .mu.g,
vol. <10 .mu.l) in microfuge tubes. The mixture was mixed
briefly by vortexing, then 40% PEG/TE (600 .mu.l, 40% polyethylene
glycol-4000, 10 mM Tris-HCl, 1 mM EDTA, 100 mM Li.sub.2OOCCH.sub.3,
pH 7.5) was added. This mixture was gently mixed and incubated at
30.degree. C. while agitating for 30 minutes. The cells were then
heat shocked at 42.degree. C. for 15 minutes, and the reaction
vessel centrifuged in a microfuge at 12,000 rpm for 5-10 seconds,
decanted and resuspended into TE (500 .mu.l, 10 mM Tris-HCl, 1 mM
EDTA pH 7.5) followed by recentrifugation. The cells were then
diluted into TE (1 ml) and aliquots (200 .mu.l) were spread onto
the selective media previously prepared in 150 mm growth plates
(VWR).
[0259] Alternatively, instead of multiple small reactions, the
transformation was performed using a single, large scale reaction,
wherein reagent amounts were scaled up accordingly.
[0260] The selective media used was a synthetic complete dextrose
agar lacking uracil (SCD-Ura) prepared as described in Kaiser et
al., Methods in Yeast Genetics, Cold Spring Harbor Press, Cold
Spring Harbor, N.Y., p. 208-210 (1994). Transformants were grown at
30.degree. C. for 2-3 days.
[0261] The detection of colonies secreting amylase was performed by
including red starch in the selective growth media. Starch was
coupled to the red dye (Reactive Red-120, Sigma) as per the
procedure described by Biely et al., Anal. Biochem., 172:176-179
(1988). The coupled starch was incorporated into the SCD-Ura agar
plates at a final concentration of 0.15% (w/v), and was buffered
with potassium phosphate to a pH of 7.0 (50-100 mM final
concentration).
[0262] The positive colonies were picked and streaked across fresh
selective media (onto 150 mm plates) in order to obtain well
isolated and identifiable single colonies. Well isolated single
colonies positive for amylase secretion were detected by direct
incorporation of red starch into buffered SCD-Ura agar. Positive
colonies were determined by their ability to break down starch
resulting in a clear halo around the positive colony visualized
directly.
[0263] 4. Isolation of DNA by PCR Amplification
[0264] When a positive colony was isolated, a portion of it was
picked by a toothpick and diluted into sterile water (30 .mu.l) in
a 96 well plate. At this time, the positive colonies were either
frozen and stored for subsequent analysis or immediately amplified.
An aliquot of cells (5 .mu.l) was used as a template for the PCR
reaction in a 25 .mu.l volume containing: 0.5 .mu.l Klentaq
(Clontech, Palo Alto, Calif.); 4.0 .mu.l 10 mM dNTP's (Perkin
Elmer-Cetus); 2.5 .mu.l Kentaq buffer (Clontech); 0.25 .mu.l
forward oligo 1; 0.25 .mu.l reverse oligo 2; 12.5 .mu.l distilled
water. The sequence of the forward oligonucleotide 1 was:
6 (SEQ ID NO:3) 5'-TGTAAAACGACGGCCAGTTAAATAGACCTGCAATTATTAA-
TCT-3'
[0265] The sequence of reverse oligonucleotide 2 was:
7 (SEQ ID NO:4) 5'-CAGGAAACAGCTATGACCACCTGCACACCTGCAAATCCA-
TT-3'
[0266] PCR was then performed as follows:
8 a. Denature 92.degree. C., 5 minutes b. 3 cycles of: Denature
92.degree. C., 30 seconds Anneal 59.degree. C., 30 seconds Extend
72.degree. C., 60 seconds c. 3 cycles of: Denature 92.degree. C.,
30 seconds Anneal 57.degree. C., 30 seconds Extend 72.degree. C.,
60 seconds d. 25 cycles of: Denature 92.degree. C., 30 seconds
Anneal 55.degree. C., 30 seconds Extend 72.degree. C., 60 seconds
e. Hold 4.degree. C.
[0267] The underlined regions of the oligonucleotides annealed to
the ADH promoter region and the amylase region, respectively, and
amplified a 307 bp region from vector pSST-AMY.0 when no insert was
present. Typically, the first 18 nucleotides of the 5' end of these
oligonucleotides contained annealing sites for the sequencing
primers. Thus, the total product of the PCR reaction from an empty
vector was 343 bp. However, signal sequence-fused cDNA resulted in
considerably longer nucleotide sequences.
[0268] Following the PCR, an aliquot of the reaction (5 .mu.l) was
examined by agarose gel electrophoresis in a 1% agarose gel using a
Tris-Borate-EDTA (TBE) buffering system as described by Sambrook et
al., supra. Clones resulting in a single strong PCR product larger
than 400 bp were further analyzed by DNA sequencing after
purification with a 96 Qiaquick PCR clean-up column (Qiagen Inc.,
Chatsworth, Calif.).
Example 3
Isolation of cDNA Clones Using Signal Algorithm Analysis
[0269] Various polypeptide-encoding nucleic acid sequences were
identified by applying a proprietary signal sequence finding
algorithm developed by Genentech, Inc. (South San Francisco,
Calif.) upon ESTs as well as clustered and assembled EST fragments
from public (e.g., GenBank) and/or private (LIFESEQ.RTM., Incyte
Pharmaceuticals, Inc., Palo Alto, Calif.) databases. The signal
sequence algorithm computes a secretion signal score based on the
character of the DNA nucleotides surrounding the first and
optionally the second methionine codon(s) (ATG) at the 5'-end of
the sequence or sequence fragment under consideration. The
nucleotides following the first ATG must code for at least 35
unambiguous amino acids without any stop codons. If the first ATG
has the required amino acids, the second is not examined. If
neither meets the requirement, the candidate sequence is not
scored. In order to determine whether the EST sequence contains an
authentic signal sequence, the DNA and corresponding amino acid
sequences surrounding the ATG codon are scored using a set of seven
sensors (evaluation parameters) known to be associated with
secretion signals. Use of this algorithm resulted in the
identification of numerous polypeptide-encoding nucleic acid
sequences.
Example 4
Isolation of cDNA Clones Encoding Human PRO Polypeptides
[0270] Using the techniques described in Examples 1 to 3 above,
numerous full-length cDNA clones were identified as encoding PRO
polypeptides as disclosed herein. These cDNAs were then deposited
under the terms of the Budapest Treaty with the American Type
Culture Collection, 10801 University Blvd., Manassas, Va.
20110-2209, USA (ATCC) as shown in Table 7, which is disclosed in
the parent application U.S. application Ser. No. 10/052,586, filed
Jan. 15, 2002 and is expressly and specifically incorporated herein
by reference for the disclosure describing and disclosed in Table
7. In addition, DNA56859-1445 is ATCC Deposit No: 203019, deposited
Jun. 23, 1998.
[0271] These deposits were made under the provisions of the
Budapest Treaty on the International Recognition of the Deposit of
Microorganisms for the Purpose of Patent Procedure and the
Regulations there under (Budapest Treaty). This assures maintenance
of a viable culture of the deposit for 30 years from the date of
deposit and for at least five (5) years after the most recent
request for the furnishing of a sample of the deposit received by
the depository. The deposits will be made available by ATCC under
the terms of the Budapest Treaty, and subject to an agreement
between Genentech, Inc. and ATCC, which assures that all
restrictions imposed by the depositor on the availability to the
public of the deposited material will be irrevocably removed upon
the granting of the pertinent U.S. patent, assures permanent and
unrestricted availability of the progeny of the culture of the
deposit to the public upon issuance of the pertinent U.S. patent or
upon laying open to the public of any U.S. or foreign patent
application, whichever comes first, and assures availability of the
progeny to one determined by the U.S. Commissioner of Patents and
Trademarks to be entitled thereto according to 35 U.S.C. .sctn.122
and the Commissioner's rules pursuant thereto (including 37 C.F.R.
.sctn.1.14 with particular reference to 886 OG 638).
[0272] The assignee of the present application has agreed that if a
culture of the materials on deposit should die or be lost or
destroyed when cultivated under suitable conditions, the materials
will be promptly replaced on notification with another of the same.
Availability of the deposited material is not to be construed as a
license to practice the invention in contravention of the rights
granted under the authority of any government in accordance with
its patent laws.
Example 5
Use of PRO as a Hybridization Probe
[0273] The following method describes use of a nucleotide sequence
encoding PRO as a hybridization probe.
[0274] DNA comprising the coding sequence of full-length or mature
PRO as disclosed herein is employed as a probe to screen for
homologous DNAs (such as those encoding naturally-occurring
variants of PRO) in human tissue cDNA libraries or human tissue
genomic libraries.
[0275] Hybridization and washing of filters containing either
library DNAs is performed under the following high stringency
conditions. Hybridization of radiolabeled PRO-derived probe to the
filters is performed in a solution of 50% formamide, 5.times.SSC,
0.1% SDS, 0.1% sodium pyrophosphate, 50 mM sodium phosphate, pH
6.8, 2.times. Denhardt's solution, and 10% dextran sulfate at
42.degree. C. for 20 hours. Washing of the filters is performed in
an aqueous solution of 0.1.times.SSC and 0.1% SDS at 42.degree.
C.
[0276] DNAs having a desired sequence identity with the DNA
encoding full-length native sequence PRO can then be identified
using standard techniques known in the art.
Example 6
Expression of PRO in E. coli
[0277] This example illustrates preparation of an unglycosylated
form of PRO by recombinant expression in E. coli.
[0278] The DNA sequence encoding PRO is initially amplified using
selected PCR primers. The primers should contain restriction enzyme
sites which correspond to the restriction enzyme sites on the
selected expression vector. A variety of expression vectors may be
employed. An example of a suitable vector is pBR322 (derived from
E. coli, see Bolivar et al., Gene, 2:95 (1977)) which contains
genes for ampicillin and tetracycline resistance. The vector is
digested with restriction enzyme and dephosphorylated. The PCR
amplified sequences are then ligated into the vector. The vector
will preferably include sequences which encode for an antibiotic
resistance gene, a trp promoter, a polyhis leader (including the
first six STII codons, polyhis sequence, and enterokinase cleavage
site), the PRO coding region, lambda transcriptional terminator,
and an argU gene.
[0279] The ligation mixture is then used to transform a selected E.
coli strain using the methods described in Sambrook et al., supra.
Transformants are identified by their ability to grow on LB plates
and antibiotic resistant colonies are then selected. Plasmid DNA
can be isolated and confirmed by restriction analysis and DNA
sequencing.
[0280] Selected clones can be grown overnight in liquid culture
medium such as LB broth supplemented with antibiotics. The
overnight culture may subsequently be used to inoculate a larger
scale culture. The cells are then grown to a desired optical
density, during which the expression promoter is turned on.
[0281] After culturing the cells for several more hours, the cells
can be harvested by centrifugation. The cell pellet obtained by the
centrifugation can be solubilized using various agents known in the
art, and the solubilized PRO protein can then be purified using a
metal chelating column under conditions that allow tight binding of
the protein.
[0282] PRO may be expressed in E. coli in a poly-His tagged form,
using the following procedure. The DNA encoding PRO is initially
amplified using selected PCR primers. The primers will contain
restriction enzyme sites which correspond to the restriction enzyme
sites on the selected expression vector, and other useful sequences
providing for efficient and reliable translation initiation, rapid
purification on a metal chelation column, and proteolytic removal
with enterokinase. The PCR-amplified, poly-His tagged sequences are
then ligated into an expression vector, which is used to transform
an E. coli host based on strain 52 (W3110 fuhA(tonA) lon galE
rpoHts(htpRts) clpP(lacIq). Transformants are first grown in LB
containing 50 mg/ml carbenicillin at 30.degree. C. with shaking
until an O.D.600 of 3-5 is reached. Cultures are then diluted
50-100 fold into CRAP media (prepared by mixing 3.57 g
(NH.sub.4).sub.2SO.sub.4, 0.71 g sodium citrate.2H2O, 1.07 g KCl,
5.36 g Difco yeast extract, 5.36 g Sheffield hycase SF in 500 mL
water, as well as 110 mM MPOS, pH 7.3, 0.55% (w/v) glucose and 7 mM
MgSO.sub.4) and grown for approximately 20-30 hours at 30.degree.
C. with shaking. Samples are removed to verify expression by
SDS-PAGE analysis, and the bulk culture is centrifuged to pellet
the cells. Cell pellets are frozen until purification and
refolding.
[0283] E. coli paste from 0.5 to 1 L fermentations (6-10 g pellets)
is resuspended in 10 volumes (w/v) in 7 M guanidine, 20 mM Tris, pH
8 buffer. Solid sodium sulfite and sodium tetrathionate is added to
make final concentrations of 0.1M and 0.02 M, respectively, and the
solution is stirred overnight at 4.degree. C. This step results in
a denatured protein with all cysteine residues blocked by
sulfitolization. The solution is centrifuged at 40,000 rpm in a
Beckman Ultracentifuge for 30 min. The supernatant is diluted with
3-5 volumes of metal chelate column buffer (6 M guanidine, 20 mM
Tris, pH 7.4) and filtered through 0.22 micron filters to clarify.
The clarified extract is loaded onto a 5 ml Qiagen Ni-NTA metal
chelate column equilibrated in the metal chelate column buffer. The
column is washed with additional buffer containing 50 mM imidazole
(Calbiochem, Utrol grade), pH 7.4. The protein is eluted with
buffer containing 250 mM imidazole. Fractions containing the
desired protein are pooled and stored at 4.degree. C. Protein
concentration is estimated by its absorbance at 280 nm using the
calculated extinction coefficient based on its amino acid
sequence.
[0284] The proteins are refolded by diluting the sample slowly into
freshly prepared refolding buffer consisting of: 20 mM Tris, pH
8.6, 0.3 M NaCl, 2.5 M urea, 5 mM cysteine, 20 mM glycine and 1 mM
EDTA. Refolding volumes are chosen so that the final protein
concentration is between 50 to 100 micrograms/ml. The refolding
solution is stirred gently at 4.degree. C. for 12-36 hours. The
refolding reaction is quenched by the addition of TFA to a final
concentration of 0.4% (pH of approximately 3). Before further
purification of the protein, the solution is filtered through a
0.22 micron filter and acetonitrile is added to 2-10% final
concentration. The refolded protein is chromatographed on a Poros
R1/H reversed phase column using a mobile buffer of 0.1% TFA with
elution with a gradient of acetonitrile from 10 to 80%. Aliquots of
fractions with A280 absorbance are analyzed on SDS polyacrylamide
gels and fractions containing homogeneous refolded protein are
pooled. Generally, the properly refolded species of most proteins
are eluted at the lowest concentrations of acetonitrile since those
species are the most compact with their hydrophobic interiors
shielded from interaction with the reversed phase resin. Aggregated
species are usually eluted at higher acetonitrile concentrations.
In addition to resolving misfolded forms of proteins from the
desired form, the reversed phase step also removes endotoxin from
the samples.
[0285] Fractions containing the desired folded PRO polypeptide are
pooled and the acetonitrile removed using a gentle stream of
nitrogen directed at the solution. Proteins are formulated into 20
mM Hepes, pH 6.8 with 0.14 M sodium chloride and 4% mannitol by
dialysis or by gel filtration using G25 Superfine (Pharmacia)
resins equilibrated in the formulation buffer and sterile
filtered.
[0286] Many of the PRO polypeptides disclosed herein were
successfully expressed as described above.
Example 7
Expression of PRO in Mammalian Cells
[0287] This example illustrates preparation of a potentially
glycosylated form of PRO by recombinant expression in mammalian
cells.
[0288] The vector, pRK5 (see EP 307,247, published Mar. 15, 1989),
is employed as the expression vector. Optionally, the PRO DNA is
ligated into pRK5 with selected restriction enzymes to allow
insertion of the PRO DNA using ligation methods such as described
in Sambrook et al., supra. The resulting vector is called
pRK5-PRO.
[0289] In one embodiment, the selected host cells may be 293 cells.
Human 293 cells (ATCC CCL 1573) are grown to confluence in tissue
culture plates in medium such as DMEM supplemented with fetal calf
serum and optionally, nutrient components and/or antibiotics. About
10 .mu.g pRK5-PRO DNA is mixed with about 1 .mu.g DNA encoding the
VA RNA gene [Thimmappaya et al., Cell 31:543 (1982)] and dissolved
in 500 .mu.l of 1 mM Tris-HCl, 0.1 mM EDTA, 0.227 M CaCl.sub.2. To
this mixture is added, dropwise, 500 .mu.l of 50 mM HEPES (pH
7.35), 280 mM NaCl, 1.5 mM NaPO.sub.4, and a precipitate is allowed
to form for 10 minutes at 25.degree. C. The precipitate is
suspended and added to the 293 cells and allowed to settle for
about four hours at 37.degree. C. The culture medium is aspirated
off and 2 ml of 20% glycerol in PBS is added for 30 seconds. The
293 cells are then washed with serum free medium, fresh medium is
added and the cells are incubated for about 5 days.
[0290] Approximately 24 hours after the transfections, the culture
medium is removed and replaced with culture medium (alone) or
culture medium containing 200 .mu.Ci/ml .sup.35S-cysteine and 200
.mu.Ci/ml .sup.35S-methionine. After a 12 hour incubation, the
conditioned medium is collected, concentrated on a spin filter, and
loaded onto a 15% SDS gel. The processed gel may be dried and
exposed to film for a selected period of time to reveal the
presence of PRO polypeptide. The cultures containing transfected
cells may undergo further incubation (in serum free medium) and the
medium is tested in selected bioassays.
[0291] In an alternative technique, PRO may be introduced into 293
cells transiently using the dextran sulfate method described by
Somparyrac et al., Proc. Natl. Acad. Sci., 12:7575 (1981). 293
cells are grown to maximal density in a spinner flask and 700 .mu.g
pRK5-PRO DNA is added. The cells are first concentrated from the
spinner flask by centrifugation and washed with PBS. The
DNA-dextran precipitate is incubated on the cell pellet for four
hours. The cells are treated with 20% glycerol for 90 seconds,
washed with tissue culture medium, and re-introduced into the
spinner flask containing tissue culture medium, 5 .mu.g/ml bovine
insulin and 0.1 .mu.g/ml bovine transferrin. After about four days,
the conditioned media is centrifuged and filtered to remove cells
and debris. The sample containing expressed PRO can then be
concentrated and purified by any selected method, such as dialysis
and/or column chromatography.
[0292] In another embodiment, PRO can be expressed in CHO cells.
The pRK5-PRO can be transfected into CHO cells using known reagents
such as CaPO.sub.4 or DEAE-dextran. As described above, the cell
cultures can be incubated, and the medium replaced with culture
medium (alone) or medium containing a radiolabel such as
.sup.35S-methionine. After determining the presence of PRO
polypeptide, the culture medium may be replaced with serum free
medium. Preferably, the cultures are incubated for about 6 days,
and then the conditioned medium is harvested. The medium containing
the expressed PRO can then be concentrated and purified by any
selected method.
[0293] Epitope-tagged PRO may also be expressed in host CHO cells.
The PRO may be subcloned out of the pRK5 vector. The subclone
insert can undergo PCR to fuse in frame with a selected epitope tag
such as a poly-his tag into a Baculovirus expression vector. The
poly-his tagged PRO insert can then be subcloned into a SV40 driven
vector containing a selection marker such as DHFR for selection of
stable clones. Finally, the CHO cells can be transfected (as
described above) with the SV40 driven vector. Labeling may be
performed, as described above, to verify expression. The culture
medium containing the expressed poly-His tagged PRO can then be
concentrated and purified by any selected method, such as by
Ni.sup.2+-chelate affinity chromatography.
[0294] PRO may also be expressed in CHO and/or COS cells by a
transient expression procedure or in CHO cells by another stable
expression procedure.
[0295] Stable expression in CHO cells is performed using the
following procedure. The proteins are expressed as an IgG construct
(immunoadhesin), in which the coding sequences for the soluble
forms (e.g. extracellular domains) of the respective proteins are
fused to an IgG1 constant region sequence containing the hinge, CH2
and CH2 domains and/or is a poly-His tagged form.
[0296] Following PCR amplification, the respective DNAs are
subcloned in a CHO expression vector using standard techniques as
described in Ausubel et al., Current Protocols of Molecular
Biology, Unit 3.16, John Wiley and Sons (1997). CHO expression
vectors are constructed to have compatible restriction sites 5' and
3' of the DNA of interest to allow the convenient shuttling of
cDNA's. The vector used expression in CHO cells is as described in
Lucas et al., Nucl. Acids Res. 24:9 (1774-1779 (1996), and uses the
SV40 early promoter/enhancer to drive expression of the cDNA of
interest and dihydrofolate reductase (DHFR). DHFR expression
permits selection for stable maintenance of the plasmid following
transfection.
[0297] Twelve micrograms of the desired plasmid DNA is introduced
into approximately 10 million CHO cells using commercially
available transfection reagents Superfect.RTM. (Qiagen),
Dosper.RTM. or Fugene.RTM. (Boehringer Mannheim). The cells are
grown as described in Lucas et al., supra. Approximately
3.times.10.sup.7 cells are frozen in an ampule for further growth
and production as described below.
[0298] The ampules containing the plasmid DNA are thawed by
placement into water bath and mixed by vortexing. The contents are
pipetted into a centrifuge tube containing 10 mLs of media and
centrifuged at 1000 rpm for 5 minutes. The supernatant is aspirated
and the cells are resuspended in 10 mL of selective media (0.2
.mu.m filtered PS20 with 5% 0.2 .mu.m diafiltered fetal bovine
serum). The cells are then aliquoted into a 100 mL spinner
containing 90 mL of selective media. After 1-2 days, the cells are
transferred into a 250 mL spinner filled with 150 mL selective
growth medium and incubated at 37.degree. C. After another 2-3
days, 250 mL, 500 mL and 2000 mL spinners are seeded with
3.times.10.sup.5 cells/mL. The cell media is exchanged with fresh
media by centrifugation and resuspension in production medium.
Although any suitable CHO media may be employed, a production
medium described in U.S. Pat. No. 5,122,469, issued Jun. 16, 1992
may actually be used. A 3 L production spinner is seeded at
1.2.times.10.sup.6 cells/mL. On day 0, the cell number pH ie
determined. On day 1, the spinner is sampled and sparging with
filtered air is commenced. On day 2, the spinner is sampled, the
temperature shifted to 33.degree. C., and 30 mL of 500 g/L glucose
and 0.6 mL of 10% antifoam (e.g., 35% polydimethylsiloxane
emulsion, Dow Corning 365 Medical Grade Emulsion) taken. Throughout
the production, the pH is adjusted as necessary to keep it at
around 7.2. After 10 days, or until the viability dropped below
70%, the cell culture is harvested by centrifugation and filtering
through a 0.22 .mu.m filter. The filtrate was either stored at
4.degree. C. or immediately loaded onto columns for
purification.
[0299] For the poly-His tagged constructs, the proteins are
purified using a Ni-NTA column (Qiagen). Before purification,
imidazole is added to the conditioned media to a concentration of 5
mM. The conditioned media is pumped onto a 6 ml Ni-NTA column
equilibrated in 20 mM Hepes, pH 7.4, buffer containing 0.3 M NaCl
and 5 mM imidazole at a flow rate of 4-5 ml/min. at 4.degree. C.
After loading, the column is washed with additional equilibration
buffer and the protein eluted with equilibration buffer containing
0.25 M imidazole. The highly purified protein is subsequently
desalted into a storage buffer containing 10 mM Hepes, 0.14 M NaCl
and 4% mannitol, pH 6.8, with a 25 ml G25 Superfine (Pharmacia)
column and stored at -80.degree. C.
[0300] Immunoadhesin (Fc-containing) constructs are purified from
the conditioned media as follows. The conditioned medium is pumped
onto a 5 ml Protein A column (Pharmacia) which had been
equilibrated in 20 mM Na phosphate buffer, pH 6.8. After loading,
the column is washed extensively with equilibration buffer before
elution with 100 mM citric acid, pH 3.5. The eluted protein is
immediately neutralized by collecting 1 ml fractions into tubes
containing 275 .mu.L of 1 M Tris buffer, pH 9. The highly purified
protein is subsequently desalted into storage buffer as described
above for the poly-His tagged proteins. The homogeneity is assessed
by SDS polyacrylamide gels and by N-terminal amino acid sequencing
by Edman degradation.
[0301] Many of the PRO polypeptides disclosed herein were
successfully expressed as described above.
Example 8
Expression of PRO in Yeast
[0302] The following method describes recombinant expression of PRO
in yeast.
[0303] First, yeast expression vectors are constructed for
intracellular production or secretion of PRO from the ADH2/GAPDH
promoter. DNA encoding PRO and the promoter is inserted into
suitable restriction enzyme sites in the selected plasmid to direct
intracellular expression of PRO. For secretion, DNA encoding PRO
can be cloned into the selected plasmid, together with DNA encoding
the ADH2/GAPDH promoter, a native PRO signal peptide or other
mammalian signal peptide, or, for example, a yeast alpha-factor or
invertase secretory signal/leader sequence, and linker sequences
(if needed) for expression of PRO.
[0304] Yeast cells, such as yeast strain AB110, can then be
transformed with the expression plasmids described above and
cultured in selected fermentation media. The transformed yeast
supernatants can be analyzed by precipitation with 10%
trichloroacetic acid and separation by SDS-PAGE, followed by
staining of the gels with Coomassie Blue stain.
[0305] Recombinant PRO can subsequently be isolated and purified by
removing the yeast cells from the fermentation medium by
centrifugation and then concentrating the medium using selected
cartridge filters. The concentrate containing PRO may further be
purified using selected column chromatography resins.
[0306] Many of the PRO polypeptides disclosed herein were
successfully expressed as described above.
Example 9
Expression of PRO in Baculovirus-Infected Insect Cells
[0307] The following method describes recombinant expression of PRO
in Baculovirus-infected insect cells.
[0308] The sequence coding for PRO is fused upstream of an epitope
tag contained within a baculovirus expression vector. Such epitope
tags include poly-his tags and immunoglobulin tags (like Fc regions
of IgG). A variety of plasmids may be employed, including plasmids
derived from commercially available plasmids such as PVL1393
(Novagen). Briefly, the sequence encoding PRO or the desired
portion of the coding sequence of PRO such as the sequence encoding
the extracellular domain of a transmembrane protein or the sequence
encoding the mature protein if the protein is extracellular is
amplified by PCR with primers complementary to the 5' and 3'
regions. The 5' primer may incorporate flanking (selected)
restriction enzyme sites. The product is then digested with those
selected restriction enzymes and subcloned into the expression
vector.
[0309] Recombinant baculovirus is generated by co-transfecting the
above plasmid and BaculoGold.TM. virus DNA (Pharmingen) into
Spodoptera frugiperda ("Sf9") cells (ATCC CRL 1711) using
lipofectin (commercially available from GIBCO-BRL). After 4-5 days
of incubation at 28.degree. C., the released viruses are harvested
and used for further amplifications. Viral infection and protein
expression are performed as described by O'Reilley et al.,
Baculovirus expression vectors: A Laboratory Manual, Oxford: Oxford
University Press (1994).
[0310] Expressed poly-his tagged PRO can then be purified, for
example, by Ni.sup.2+-chelate affinity chromatography as follows.
Extracts are prepared from recombinant virus-infected Sf9 cells as
described by Rupert et al., Nature, 362:175-179 (1993). Briefly,
Sf9 cells are washed, resuspended in sonication buffer (25 mL
Hepes, pH 7.9; 12.5 mM MgCl.sub.2; 0.1 mM EDTA; 10% glycerol; 0.1%
NP40; 0.4 M KCl), and sonicated twice for 20 seconds on ice. The
sonicates are cleared by centrifugation, and the supernatant is
diluted 50-fold in loading buffer (50 mM phosphate, 300 mM NaCl,
10% glycerol, pH 7.8) and filtered through a 0.45 .mu.m filter. A
Ni.sup.2+-NTA agarose column (commercially available from Qiagen)
is prepared with a bed volume of 5 mL, washed with 25 mL of water
and equilibrated with 25 mL of loading buffer. The filtered cell
extract is loaded onto the column at 0.5 mL per minute. The column
is washed to baseline A.sub.280 with loading buffer, at which point
fraction collection is started. Next, the column is washed with a
secondary wash buffer (50 mM phosphate; 300 mM NaCl, 10% glycerol,
pH 6.0), which elutes nonspecifically bound protein. After reaching
A.sub.280 baseline again, the column is developed with a 0 to 500
mM Imidazole gradient in the secondary wash buffer. One mL
fractions are collected and analyzed by SDS-PAGE and silver
staining or Western blot with Ni.sup.2+-NTA-conjugated to alkaline
phosphatase (Qiagen). Fractions containing the eluted
His.sub.10-tagged PRO are pooled and dialyzed against loading
buffer.
[0311] Alternatively, purification of the IgG tagged (or Fc tagged)
PRO can be performed using known chromatography techniques,
including for instance, Protein A or protein G column
chromatography.
[0312] Many of the PRO polypeptides disclosed herein were
successfully expressed as described above.
Example 10
Preparation of Antibodies that Bind PRO
[0313] This example illustrates preparation of monoclonal
antibodies which can specifically bind PRO.
[0314] Techniques for producing the monoclonal antibodies are known
in the art and are described, for instance, in Goding, supra.
Immunogens that may be employed include purified PRO, fusion
proteins containing PRO, and cells expressing recombinant PRO on
the cell surface. Selection of the immunogen can be made by the
skilled artisan without undue experimentation.
[0315] Mice, such as Balb/c, are immunized with the PRO immunogen
emulsified in complete Freund's adjuvant and injected
subcutaneously or intraperitoneally in an amount from 1-100
micrograms. Alternatively, the immunogen is emulsified in MPL-TDM
adjuvant (Ribi Immunochemical Research, Hamilton, Mont.) and
injected into the animal's hind foot pads. The immunized mice are
then boosted 10 to 12 days later with additional immunogen
emulsified in the selected adjuvant. Thereafter, for several weeks,
the mice may also be boosted with additional immunization
injections. Serum samples may be periodically obtained from the
mice by retro-orbital bleeding for testing in ELISA assays to
detect anti-PRO antibodies.
[0316] After a suitable antibody titer has been detected, the
animals "positive" for antibodies can be injected with a final
intravenous injection of PRO. Three to four days later, the mice
are sacrificed and the spleen cells are harvested. The spleen cells
are then fused (using 35% polyethylene glycol) to a selected murine
myeloma cell line such as P3X63AgU.1, available from ATCC, No. CRL
1597. The fusions generate hybridoma cells which can then be plated
in 96 well tissue culture plates containing HAT (hypoxanthine,
aminopterin, and thymidine) medium to inhibit proliferation of
non-fused cells, myeloma hybrids, and spleen cell hybrids.
[0317] The hybridoma cells will be screened in an ELISA for
reactivity against PRO. Determination of "positive" hybridoma cells
secreting the desired monoclonal antibodies against PRO is within
the skill in the art.
[0318] The positive hybridoma cells can be injected
intraperitoneally into syngeneic Balb/c mice to produce ascites
containing the anti-PRO monoclonal antibodies. Alternatively, the
hybridoma cells can be grown in tissue culture flasks or roller
bottles. Purification of the monoclonal antibodies produced in the
ascites can be accomplished using ammonium sulfate precipitation,
followed by gel exclusion chromatography. Alternatively, affinity
chromatography based upon binding of antibody to protein A or
protein G can be employed.
Example 11
Purification of PRO Polypeptides Using Specific Antibodies
[0319] Native or recombinant PRO polypeptides may be purified by a
variety of standard techniques in the art of protein purification.
For example, pro-PRO polypeptide, mature PRO polypeptide, or
pre-PRO polypeptide is purified by immunoaffinity chromatography
using antibodies specific for the PRO polypeptide of interest. In
general, an immunoaffinity column is constructed by covalently
coupling the anti-PRO polypeptide antibody to an activated
chromatographic resin.
[0320] Polyclonal immunoglobulins are prepared from immune sera
either by precipitation with ammonium sulfate or by purification on
immobilized Protein A (Pharmacia LKB Biotechnology, Piscataway,
N.J.). Likewise, monoclonal antibodies are prepared from mouse
ascites fluid by ammonium sulfate precipitation or chromatography
on immobilized Protein A. Partially purified immunoglobulin is
covalently attached to a chromatographic resin such as
CnBr-activated SEPHAROSE.TM. (Pharmacia LKB Biotechnology). The
antibody is coupled to the resin, the resin is blocked, and the
derivative resin is washed according to the manufacturer's
instructions.
[0321] Such an immunoaffinity column is utilized in the
purification of PRO polypeptide by preparing a fraction from cells
containing PRO polypeptide in a soluble form. This preparation is
derived by solubilization of the whole cell or of a subcellular
fraction obtained via differential centrifugation by the addition
of detergent or by other methods well known in the art.
Alternatively, soluble PRO polypeptide containing a signal sequence
may be secreted in useful quantity into the medium in which the
cells are grown.
[0322] A soluble PRO polypeptide-containing preparation is passed
over the immunoaffinity column, and the column is washed under
conditions that allow the preferential absorbance of PRO
polypeptide (e.g. high ionic strength buffers in the presence of
detergent). Then, the column is eluted under conditions that
disrupt antibody/PRO polypeptide binding (e.g., a low pH buffer
such as approximately pH 2-3, or a high concentration of a
chaotrope such as urea or thiocyanate ion), and PRO polypeptide is
collected.
Example 12
Drug Screening
[0323] This invention is particularly useful for screening
compounds by using PRO polypeptides or binding fragment thereof in
any of a variety of drug screening techniques. The PRO polypeptide
or fragment employed in such a test may either be free in solution,
affixed to a solid support, borne on a cell surface, or located
intracellularly. One method of drug screening utilizes eukaryotic
or prokaryotic host cells which are stably transformed with
recombinant nucleic acids expressing the PRO polypeptide or
fragment. Drugs are screened against such transformed cells in
competitive binding assays. Such cells, either in viable or fixed
form, can be used for standard binding assays. One may measure, for
example, the formation of complexes between PRO polypeptide or a
fragment and the agent being tested. Alternatively, one can examine
the diminution in complex formation between the PRO polypeptide and
its target cell or target receptors caused by the agent being
tested.
[0324] Thus, the present invention provides methods of screening
for drugs or any other agents which can affect a PRO
polypeptide-associated disease or disorder. These methods comprise
contacting such an agent with an PRO polypeptide or fragment
thereof and assaying (I) for the presence of a complex between the
agent and the PRO polypeptide or fragment, or (ii) for the presence
of a complex between the PRO polypeptide or fragment and the cell,
by methods well known in the art. In such competitive binding
assays, the PRO polypeptide or fragment is typically labeled. After
suitable incubation, free PRO polypeptide or fragment is separated
from that present in bound form, and the amount of free or
uncomplexed label is a measure of the ability of the particular
agent to bind to PRO polypeptide or to interfere with the PRO
polypeptide/cell complex.
[0325] Another technique for drug screening provides high
throughput screening for compounds having suitable binding affinity
to a polypeptide and is described in detail in WO 84/03564,
published on Sep. 13, 1984. Briefly stated, large numbers of
different small peptide test compounds are synthesized on a solid
substrate, such as plastic pins or some other surface. As applied
to a PRO polypeptide, the peptide test compounds are reacted with
PRO polypeptide and washed. Bound PRO polypeptide is detected by
methods well known in the art. Purified PRO polypeptide can also be
coated directly onto plates for use in the aforementioned drug
screening techniques. In addition, non-neutralizing antibodies can
be used to capture the peptide and immobilize it on the solid
support.
[0326] This invention also contemplates the use of competitive drug
screening assays in which neutralizing antibodies capable of
binding PRO polypeptide specifically compete with a test compound
for binding to PRO polypeptide or fragments thereof. In this
manner, the antibodies can be used to detect the presence of any
peptide which shares one or more antigenic determinants with PRO
polypeptide.
Example 13
Rational Drug Design
[0327] The goal of rational drug design is to produce structural
analogs of biologically active polypeptide of interest (i.e., a PRO
polypeptide) or of small molecules with which they interact, e.g.
agonists, antagonists, or inhibitors. Any of these examples can be
used to fashion drugs which are more active or stable forms of the
PRO polypeptide or which enhance or interfere with the function of
the PRO polypeptide in vivo (c.f., Hodgson, Bio/Technology, 2:
19-21 (1991)).
[0328] In one approach, the three-dimensional structure of the PRO
polypeptide, or of an PRO polypeptide-inhibitor complex, is
determined by x-ray crystallography, by computer modeling or, most
typically, by a combination of the two approaches. Both the shape
and charges of the PRO polypeptide must be ascertained to elucidate
the structure and to determine active site(s) of the molecule. Less
often, useful information regarding the structure of the PRO
polypeptide may be gained by modeling based on the structure of
homologous proteins. In both cases, relevant structural information
is used to design analogous PRO polypeptide-like molecules or to
identify efficient inhibitors. Useful examples of rational drug
design may include molecules which have improved activity or
stability as shown by Braxton and Wells, Biochemistry, 31:7796-7801
(1992) or which act as inhibitors, agonists, or antagonists of
native peptides as shown by Athauda et al., J. Biochem.,
113:742-746 (1993).
[0329] It is also possible to isolate a target-specific antibody,
selected by functional assay, as described above, and then to solve
its crystal structure. This approach, in principle, yields a
pharmacore upon which subsequent drug design can be based. It is
possible to bypass protein crystallography altogether by generating
anti-idiotypic antibodies (anti-ids) to a functional,
pharmacologically active antibody. As a mirror image of a mirror
image, the binding site of the anti-ids would be expected to be an
analog of the original receptor. The anti-id could then be used to
identify and isolate peptides from banks of chemically or
biologically produced peptides. The isolated peptides would then
act as the pharmacore.
[0330] By virtue of the present invention, sufficient amounts of
the PRO polypeptide may be made available to perform such
analytical studies as X-ray crystallography. In addition, knowledge
of the PRO polypeptide amino acid sequence provided herein will
provide guidance to those employing computer modeling techniques in
place of or in addition to x-ray crystallography.
Example 14
Identification of PRO Polypeptides that Stimulate TNF-.alpha.
Release in Human Blood (Assay 128)
[0331] This assay shows that certain PRO polypeptides of the
present invention act to stimulate the release of TNF-.alpha. in
human blood. PRO polypeptides testing positive in this assay are
useful for, among other things, research purposes where stimulation
of the release of TNF-.alpha. would be desired and for the
therapeutic treatment of conditions wherein enhanced TNF-.alpha.
release would be beneficial. Specifically, 200 .mu.l of human blood
supplemented with 50 mM Hepes buffer (pH 7.2) is aliquoted per well
in a 96 well test plate. To each well is then added 300 .mu.l of
either the test PRO polypeptide in 50 mM Hepes buffer (at various
concentrations) or 50 mM Hepes buffer alone (negative control) and
the plates are incubated at 37.degree. C. for 6 hours. The samples
are then centrifuged and 50 .mu.l of plasma is collected from each
well and tested for the presence of TNF-.alpha. by ELISA assay. A
positive in the assay is a higher amount of TNF-.alpha. in the PRO
polypeptide treated samples as compared to the negative control
samples.
[0332] The following PRO polypeptides tested positive in this
assay:
[0333] PRO1079, PRO827, PRO791, PRO1131, PRO1316, PRO1183, PRO1343,
PRO1760, PRO1567, and PRO4333.
Example 15
Promotion of Chondrocyte Redifferentiation (Assay 129)
[0334] This assay is designed to determine whether PRO polypeptides
of the present invention show the ability to induce the
proliferation and/or redifferentiation of chondrocytes in culture.
PRO polypeptides testing positive in this assay would be expected
to be useful for the therapeutic treatment of various bone and/or
cartilage disorders such as, for example, sports injuries and
arthritis.
[0335] Porcine chondrocytes are isolated by overnight collagenase
digestion of articular cartilage of the metacarpophalangeal joint
of 4-6 month old female pigs. The isolated cells are then seeded at
25,000 cells/cm.sup.2 in Ham F-12 containing 10% FBS and 4 .mu.g/ml
gentamycin. The culture media is changed every third day. On day
12, the cells are seeded in 96 well plates at 5,000 cells/well in
100 .mu.l of the same media without serum and 100 .mu.l of either
serum-free medium (negative control), staurosporin (final
concentration of 5 nM; positive control) or the test PRO
polypeptide are added to give a final volume of 200 .mu.l/well.
After 5 days at 37.degree. C., 22 .mu.l of media containing 100
.mu.g/ml Hoechst 33342 and 50 .mu.g/ml 5-CFDA is added to each well
and incubated for an additional 10 minutes at 37.degree. C. A
picture of the green fluorescence is taken for each well and the
differentiation state of the chondrocytes is calculated by
morphometric analysis. A positive result in the assay is obtained
when the >50% of the PRO polypeptide treated cells are
differentiated (compared to the background obtained by the negative
control).
[0336] PRO6029 polypeptide tested positive in this assay.
Example 16
Microarray Analysis to Detect Overexpression of PRO Polypeptides in
Cancerous Tumors
[0337] Nucleic acid microarrays, often containing thousands of gene
sequences, are useful for identifying differentially expressed
genes in diseased tissues as compared to their normal counterparts.
Using nucleic acid microarrays, test and control mRNA samples from
test and control tissue samples are reverse transcribed and labeled
to generate cDNA probes. The cDNA probes are then hybridized to an
array of nucleic acids immobilized on a solid support. The array is
configured such that the sequence and position of each member of
the array is known. For example, a selection of genes known to be
expressed in certain disease states may be arrayed on a solid
support. Hybridization of a labeled probe with a particular array
member indicates that the sample from which the probe was derived
expresses that gene. If the hybridization signal of a probe from a
test (disease tissue) sample is greater than hybridization signal
of a probe from a control (normal tissue) sample, the gene or genes
overexpressed in the disease tissue are identified. The implication
of this result is that an overexpressed protein in a diseased
tissue is useful not only as a diagnostic marker for the presence
of the disease condition, but also as a therapeutic target for
treatment of the disease condition.
[0338] The methodology of hybridization of nucleic acids and
microarray technology is well known in the art. In the present
example, the specific preparation of nucleic acids for
hybridization and probes, slides, and hybridization conditions are
all detailed in U.S. Provisional Patent Application Ser. No.
60/193,767, filed on Mar. 31, 2000 and which is herein incorporated
by reference.
[0339] In the present example, cancerous tumors derived from
various human tissues were studied for PRO polypeptide-encoding
gene expression relative to non-cancerous human tissue in an
attempt to identify those PRO polypeptides which are overexpressed
in cancerous tumors. Two sets of experimental data were generated.
In one set, cancerous human colon tumor tissue and matched
non-cancerous human colon tumor tissue from the same patient
("matched colon control") were obtained and analyzed for PRO
polypeptide expression using the above described microarray
technology. In the second set of data, cancerous human tumor tissue
from any of a variety of different human tumors was obtained and
compared to a "universal" epithelial control sample which was
prepared by pooling non-cancerous human tissues of epithelial
origin, including liver, kidney, and lung. mRNA isolated from the
pooled tissues represents a mixture of expressed gene products from
these different tissues. Microarray hybridization experiments using
the pooled control samples generated a linear plot in a 2-color
analysis. The slope of the line generated in a 2-color analysis was
then used to normalize the ratios of (test:control detection)
within each experiment. The normalized ratios from various
experiments were then compared and used to identify clustering of
gene expression. Thus, the pooled "universal control" sample not
only allowed effective relative gene expression determinations in a
simple 2-sample comparison, it also allowed multi-sample
comparisons across several experiments.
[0340] In the present experiments, nucleic acid probes derived from
the herein described PRO polypeptide-encoding nucleic acid
sequences were used in the creation of the microarray and RNA from
the tumor tissues listed above were used for the hybridization
thereto. A value based upon the normalized ratio:experimental ratio
was designated as a "cutoff ratio". Only values that were above
this cutoff ratio were determined to be significant. Table 8 shows
the results of these experiments, demonstrating that various PRO
polypeptides of the present invention are significantly
overexpressed in various human tumor tissues as compared to a
non-cancerous human tissue control. As described above, these data
demonstrate that the PRO polypeptides of the present invention are
useful not only as diagnostic markers for the presence of one or
more cancerous tumors, but also serve as therapeutic targets for
the treatment of those tumors. Additional data for Table 8 is
present in Table 8 as disclosed in parent U.S. application Ser. No.
10/052,586, filed Jan. 15, 2002 and is specifically and expressly
incorporated herein be reference for disclosure describing and data
presented in Table 8.
9TABLE 8 Molecule is overexpressed in: as compared to: PRO839 colon
tumor universal normal control
[0341]
Sequence CWU 1
1
4 1 551 DNA homo sapiens 1 aatggctgtc ttagtacttc gcctgacagt
tgtcctggga ctgcttgtct tattcctgac 60 ctgctatgca gacgacaaac
cagacaagcc agacgacaag ccagacgact cgggcaaaga 120 cccaaagcca
gacttcccca aattcctaag cctcctgggc acagagatca ttgagaatgc 180
agtcgagttc atcctccgct ccatgtccag gagcacagga tttatggaat ttgatgataa
240 tgaaggaaaa cattcatcaa agtgacatcc tcaggacaca cccatgtggc
tcctggacaa 300 tccaagagca gccaaatcct gcttttccag tttggctcca
caagtcctcc aggacagagc 360 cctcaaagca actcccaacg agttctcagg
attcaggctc tggcttcaac caaacagaac 420 tcattttgaa caccctgact
gcatttttgc ttttagaaag ttagaataaa tatggcgctt 480 tgggatcaca
tagttgatgg agaggaaaaa aaaaaaaaaa aaaaaaaaaa aaaaaaaaaa 540
aaaaaaaaaa a 551 2 87 PRT homo sapiens 2 Met Ala Val Leu Val Leu
Arg Leu Thr Val Val Leu Gly Leu Leu Val 1 5 10 15 Leu Phe Leu Thr
Cys Tyr Ala Asp Asp Lys Pro Asp Lys Pro Asp Asp 20 25 30 Lys Pro
Asp Asp Ser Gly Lys Asp Pro Lys Pro Asp Phe Pro Lys Phe 35 40 45
Leu Ser Leu Leu Gly Thr Glu Ile Ile Glu Asn Ala Val Glu Phe Ile 50
55 60 Leu Arg Ser Met Ser Arg Ser Thr Gly Phe Met Glu Phe Asp Asp
Asn 65 70 75 80 Glu Gly Lys His Ser Ser Lys 85 3 43 DNA Artificial
Sequence synthetic oligonucleotide probe 3 tgtaaaacga cggccagtta
aatagacctg caattattaa tct 43 4 41 DNA Artificial Sequence synthetic
oligonucleotide probe 4 caggaaacag ctatgaccac ctgcacacct gcaaatccat
t 41
* * * * *