U.S. patent application number 16/272876 was filed with the patent office on 2020-02-13 for immunoregulatory structures from normally occuring proteins.
The applicant listed for this patent is Canimguide Therapeutics AB. Invention is credited to Birgitta Clinchy, Leif Hakansson.
Application Number | 20200048331 16/272876 |
Document ID | / |
Family ID | 39709034 |
Filed Date | 2020-02-13 |
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United States Patent
Application |
20200048331 |
Kind Code |
A1 |
Hakansson; Leif ; et
al. |
February 13, 2020 |
IMMUNOREGULATORY STRUCTURES FROM NORMALLY OCCURING PROTEINS
Abstract
The present invention relates to isolated protein sequences that
correspond to cell binding peptides, fragments, neo-structures
and/or neo-epitopes of a normally occurring serum protein present
in human tissue, wherein the peptide, fragment, neo-structure
and/or neo-epitope has an immunoregulatory activity and is the
result of either an enhanced proteolytic activity and/or
conformational changes in a tissue, or a malignant tumour. In the
present patent application, a common structure of several of these
peptides, fragments, neo-structures and/or neo-epitopes, having
immunoregulatory activity by binding to receptors on immune cells,
has been identified. The present invention further also relates to
monoclonal and/or polyclonal antibodies directed to a cell binding
fragment of a normally occurring serum protein present in human
tissue, as described above.
Inventors: |
Hakansson; Leif; (Hollviken,
SE) ; Clinchy; Birgitta; (Ljungsbro, SE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Canimguide Therapeutics AB |
Hollviken |
|
SE |
|
|
Family ID: |
39709034 |
Appl. No.: |
16/272876 |
Filed: |
February 11, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15667058 |
Aug 2, 2017 |
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16272876 |
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14815471 |
Jul 31, 2015 |
9796777 |
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15667058 |
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12599484 |
Nov 9, 2009 |
9120874 |
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PCT/SE2008/000314 |
May 8, 2008 |
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14815471 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61P 37/02 20180101;
G01N 2333/55 20130101; G01N 2500/10 20130101; C07K 16/18 20130101;
A61P 35/00 20180101; G01N 2333/765 20130101; C07K 2317/34 20130101;
G01N 33/57484 20130101; C07K 14/765 20130101; A61P 37/06 20180101;
A61K 2039/505 20130101; G01N 33/5044 20130101; A61K 38/00
20130101 |
International
Class: |
C07K 16/18 20060101
C07K016/18; G01N 33/574 20060101 G01N033/574; G01N 33/50 20060101
G01N033/50; C07K 14/765 20060101 C07K014/765 |
Foreign Application Data
Date |
Code |
Application Number |
May 8, 2007 |
SE |
0701099-4 |
May 8, 2007 |
SE |
0701100-0 |
Nov 15, 2007 |
SE |
0702520-8 |
Claims
1.-26. (canceled)
27. A method of using an isolated neo-epitope of albumin as an
immunoinhibitor in an inflammatory condition or disease, the
isolated neo-epitope comprising an amino acid sequence selected
from the group consisting of: LVNEVTEFAK (SEQ ID NO:104), SLHTLFGDK
(SEQ ID NO:84), LCTVATLR (SEQ ID NO:85), ETYGEMADCCAK (SEQ ID
NO:86), YLYEIAR (SEQ ID NO:87), LDELRDEGK (SEQ ID NO:88),
YICENQDSISSK (SEQ ID NO:89), LKECCEKPLLEK (SEQ ID NO:90),
HPDYSVVLLLR (SEQ ID NO:91), CCAAADPHECYAK (SEQ ID NO:92),
QNCELFEQLGEYK (SEQ ID NO:93), FQNALLVR (SEQ ID NO:94), CCTESLVNR
(SEQ ID NO:95), and AVMDDFAAFVEK (SEQ ID NO:96), the method
comprising administering the isolated neo-epitope to a subject
having an inflammatory condition or disease.
28. The method of claim 27, wherein the isolated neo-epitope of
albumin comprises the amino acid sequence of YLYEIAR (SEQ ID NO:
87)
29. The method of claim 27, wherein the isolated neo-epitope of
albumin comprises the amino acid sequence of KYLYEIAR (SEQ ID NO:
115).
30. The method of claim 27, wherein the isolated neo-epitope of
albumin comprises the amino acid sequence of KLVNEVTEFAKT (SEQ ID
NO: 106).
31. The method of claim 27, wherein the isolated neo-epitope of
albumin comprises the amino acid sequence of KLDELRDEGKAS (SEQ ID
NO: 112).
32. The method of claim 27, wherein the isolated neo-epitope of
albumin comprises the amino acid sequence of ELFEQLGEYKFQNALLVR
(SEQ ID NO: 147).
33. The method of claim 27, wherein the isolated neo-epitope of
albumin binds to an immune cell.
34. The method of claim 27, wherein the inflammatory condition or
disease is selected from the group consisting of: psoriasis, T-cell
lymphoma, allograft rejection, GVH, ischemia-reperfusion injury,
chronic inflammatory diseases, and an autoimmune disease.
35. A method of using an isolated neo-epitope of albumin as an
immunoinhibitor in an inflammatory condition or disease, the
isolated immune cell binding peptide comprising the amino acid
sequence NEETFLKKYLYE (SEQ ID NO: 110), the method comprising
administering the isolated neo-epitope of albumin to a subject
having an inflammatory condition or disease.
36. The method of claim 35, wherein the inflammatory condition or
disease is selected from the group consisting of psoriasis, T-cell
lymphoma, allograft rejection, GVH, ischemia-reperfusion injury,
chronic inflammatory diseases and an autoimmune disease.
37. A monoclonal antibody directed to an immune cell binding
neo-epitope of albumin, the isolated immune cell binding
neo-epitope comprising an amino acid sequence selected from the
group consisting of: LVNEVTEFAK (SEQ ID NO: 104), SLHTLFGDK (SEQ ID
NO:84), LCTVATLR (SEQ ID NO:85), ETYGEMADCCAK (SEQ ID NO:86),
YLYEIAR (SEQ ID NO:87), LDELRDEGK (SEQ ID NO:88), YICENQDSISSK (SEQ
ID NO:89), LKECCEKPLLEK (SEQ ID NO:90), HPDYSVVLLLR (SEQ ID NO:91),
CCAAADPHECYAK (SEQ ID NO:92), QNCELFEQLGEYK (SEQ ID NO:93),
FQNALLVR (SEQ ID NO:94), CCTESLVNR (SEQ ID NO:95), and AVMDDFAAFVEK
(SEQ ID NO:96).
38. The monoclonal antibody of claim 37, wherein the immune cell
binding neo-epitope of albumin comprises the amino acid sequence
YLYEIAR (SEQ ID NO: 87).
Description
[0001] The present application is a continuation of U.S. patent
application Ser. No. 15/667,058, filed Aug. 2, 2017, now abandoned,
which is a continuation of U.S. patent application Ser. No.
14/815,471 filed Jul. 31, 2015, now U.S. Pat. No. 9,796,777 which
is a continuation of U.S. patent application Ser. No. 12/599,484
filed Nov. 9, 2009, now U.S. Pat. No. 9,120,874, which is the US
National Phase of PCT Application No. PCT/SE2008/000314 filed May
8, 2008, which claims the benefit of Swedish Patent Application No.
0701099-4 filed May 8, 2007, Swedish Patent Application No.
0701100-0 filed May 8, 2007, and Swedish Patent Application No.
0702520-8 filed Nov. 15, 2007, each of which is hereby incorporated
by reference in its entirety. The present application is
accompanied by an electronic sequence listing entitled
CANIG004C3.TXT, created and last modified Nov. 2, 2019 which is
34,668 bytes in size.
TECHNICAL FIELD
[0002] The present invention relates to certain identified protein
sequences having an immunoregulatory effect, as well as antibodies
directed to such protein sequences and to methods for identifying
such.
BACKGROUND OF THE INVENTION
[0003] Although data indicate that the immune system is of major
importance for cancer control, malignant tumours continue to grow
and the efficacy of immunotherapy is rather poor with an objective
remission rate of 15-30%. There can be several reasons for this
apparent paradox: [0004] Tumours avoid the recognition by the
immune system by not expressing tumour associated antigens properly
[0005] Tumour associated antigens (often self antigens), which are
too weak to elicit an adequate immune response [0006] Induction of
tolerance [0007] Cancer related immunosuppression, which prevents
an adequate immune response
[0008] These alternatives require completely different therapeutic
strategies, either proper stimulation of the immune system or
control of cancer related immunosuppressor mechanisms.
[0009] Immunosuppression in cancer is mainly characterized by:
Reduced proliferative and cytotoxic capacity of lymphocytes, in
particular tumour infiltrating lymphocytes, poor migration of
inflammatory cells, reduced production and response to IL-2,
difficulties to elicit an immune response by vaccination, also
against other than tumour related antigens and pathological
cytokine production. This dysregulation of the immune system
results in poor immune mediated cancer control and a paraneoplastic
syndrome (subfebrility, fatigue, anorexia, weight loss and
deterioration of laboratory parameters).
[0010] Immunostimulatory therapeutic strategies using cytokines
(e.g. interferons, interleukins) or vaccination, in order to
enhance the immune mediated reactivity to the tumour, has been
tried for several decades, but have so far had only very limited
success. This indicates that immunostimulation in order to overcome
a poor immune response in cancer patients might be suppressed by
other so far unidentified mechanisms.
[0011] We have in two previous patent applications described two
fundamental immunoregulatory mechanisms of relevance to all types
of malignant tumours. In the first of these applications the
importance of Fc-receptor modulation and ways to overcome this
cancer related immunosuppression by modulating Fc-receptor
cross-linking was demonstrated. In this patent application also
proteolytic fragments of normally occurring proteins were
demonstrated to induce pathological monokine production. In the
second patent application some of these neo-structures were found
to be integrin binding/blocking and their occurrence and
immunoregulatory activity was further analysed by using monoclonal
antibodies directed against albumin derived neo-structures. In the
latter patent application also the occurrence and importance of
auto-antibodies to these neo-structures is described.
SUMMARY OF THE PRESENT INVENTION
[0012] In the present patent application, several protein
sequences, such as peptides, peptide fragments, neo-structures
and/or neo-epitopes, of a protein normally occurring in serum,
which are binding to immune cells are disclosed. Some of their
immunoregulatory activities are described.
[0013] What is more, in the present patent application, the
structure of several of these peptides, peptide fragments,
neo-structures and/or neo-epitopes, having immunoregulatory
activity by binding to receptors on immune cells, have been
identified.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
[0014] The present invention relates to an immune cell binding
protein sequence of a protein normally occurring in serum, such as
to an isolated cell binding peptide, peptide fragment,
neo-structure and/or neo-epitope of a protein normally occurring in
serum, which is present in a human tissue, wherein said peptide,
peptide fragment, neo-structure and/or neo-epitope has an
immunoregulatory activity and said peptide, peptide fragment,
neo-structure and/or neo-epitope is the result of an enhanced
proteolytic activity and/or denaturing in an inflammatory tissue
and/or a malignant tumour. Specific examples of such immune cell
binding protein sequences are selected from the amino acid
sequences listed e.g. as SEQ.ID.NO(s). 1-81, such as in particular
from the sequences corresponding to SEQ.ID.NO(s). 26, 80, and
81.
[0015] Consequently, the present invention also relates to the use
as a medicine of an immune cell binding protein sequence of a
protein normally occurring in serum, such as an isolated cell
binding peptide, peptide fragment, neo-structure and/or
neo-epitope, which is present in a human tissue, wherein said
peptide, peptide fragment, neo-structure and/or neo-epitope has an
immunoregulatory activity and said peptide, peptide fragment,
neo-structure and/or neo-epitope is the result of an enhanced
proteolytic activity and/or denaturing in an inflammatory tissue
and/or a malignant tumour, selected from the amino acid sequences
listed as SEQ.ID.NO(s). 1-81, such as in particular selected from
the sequences corresponding to SEQ.ID.NO(s). 26, 80, and 81.
[0016] In particular, the present invention relates to the use of
an immune cell binding protein sequence of a protein normally
occurring in serum, according to the present invention, selected
from the amino acid sequences listed as SEQ.ID.NO(s). 1-81, such as
in particular selected from the sequences corresponding to
SEQ.ID.NO(s). 26, 80, and 81, for diagnosing, treating and/or
preventing cancer in a patient in need thereof.
[0017] A preferred embodiment thereof is a monoclonal antibody
directed to an immune cell binding protein sequence of a protein
normally occurring in serum, such as an isolated cell binding
peptide, peptide fragment, neo-structure and/or neo-epitope, which
is present in a human tissue, wherein said peptide, peptide
fragment, neo-structure and/or neo-epitope has an immunoregulatory
activity and said peptide, peptide fragment, neo-structure and/or
neo-epitope is the result of an enhanced proteolytic activity
and/or denaturing in an inflammatory tissue and/or a malignant
tumour. In a presently preferred embodiment, such a monoclonal
antibody is directed against at least one of the protein sequences
corresponding to a sequence selected from the amino acid sequences
listed as SEQ.ID.NO(s). 1-81, such as in particular selected from
the sequences corresponding to SEQ.ID.NO(s). 26, 80, and 81.
Another, equally preferred embodiment of the present invention is a
polyclonal rabbit anti-3028 antibody, which is herein demonstrated,
as well as a polyclonal rabbit anti-3218 or anti-3315 antibody,
i.e. a polyclonal rabbit antibody that is directed against at least
one of the protein sequences corresponding to SEQ.ID.NO(s). 26, 80
or 81. Such an antibody is typically used for different diagnose
and/or research methods.
[0018] A further aspect of the invention relates to a method for
diagnosing the presence of a malignant tumour by determining the
response to an antibody as described above.
[0019] A still further aspect of the invention relates to a
compound inhibiting the activity of an immune cell binding protein
sequence of a protein normally occurring in serum, such as an
isolated cell binding peptide, peptide fragment, neo-structure
and/or neo-epitope, which is present in a human tissue, wherein
said peptide, peptide fragment, neo-structure and/or neo-epitope
has an immunoregulatory activity and said peptide, peptide
fragment, neo-structure and/or neo-epitope is the result of an
enhanced proteolytic activity and/or denaturing in an inflammatory
tissue and/or a malignant tumour.
[0020] A further aspect of the invention relates to a method for
treating any malignant tumour by administering a compound
inhibiting the occurrence of an immune cell binding protein
sequence of a protein normally occurring in serum, such as an
isolated cell binding peptide, peptide fragment, neo-structure
and/or neo-epitope, according to the present invention, which said
peptide, peptide fragment, neo-structure and/or neo-epitope has an
immunoregulatory activity and is the result of a cancer or malign
tumour.
[0021] A preferred embodiment of the method consists in that an
antibody raised against said cell binding peptide, peptide
fragment, neo-structure and/or neo-epitope is administered in an
amount sufficient to raise an immune response to any malignant
tumour.
[0022] A further aspect of the invention relates to a method for
treating a malignant tumour by inhibiting the activity of said
immunoregulatory peptide, peptide fragment, neo-structure and/or
neo-epitope by using standard drug developing pharmacological
principles producing receptor blocking drugs or drugs inhibiting
signal transduction from the receptors of said peptide, peptide
fragment, neo-structure and/or neo-epitope.
[0023] In particular again, the present invention for the first
time discloses that an immune cell binding protein sequence of a
protein normally occurring in serum, according to the present
invention, such as an isolated cell binding peptide, peptide
fragment, neo-structure and/or neo-epitope, being the result of an
enhanced proteolytic activity and/or denaturing in an inflammatory
tissue and/or a malignant tumour, has immunoregulatory, inhibitory
activity, i.e. that it is a physiological immunoinhibitor. The
present invention thus further relates to the use of an isolated
immune cell binding peptide, peptide fragment, neo-structure and/or
neo-epitope of a protein normally occurring in serum, according to
the present invention, for immunoregulation not only in cancer, but
also in interleukin-2 dependent and/or inflammatory conditions
and/or diseases, such as psoriasis, T-cell lymphoma, allograft
rejection, GVH, ischemia-reperfusion injury, chronic inflammatory
diseases and/or autoimmune diseases.
[0024] A still further aspect of the invention relates to a method
for treating interleukin-2 dependent and/or inflammatory conditions
and/or diseases by administering a therapeutically effective amount
of the immunosuppressive peptide, peptide fragment, neo-structure
and/or neo-epitope of a protein normally occurring in serum,
according to the present invention.
[0025] One presently preferred embodiment of the present invention
relates to a protein sequence, such as a peptide, peptide fragment,
neo-structure and/or neo-epitope of normal serum albumin having a
first glutamic acid at a distance of 3 to 7 amino acids from any
lysine present in said sequence, preferably 4 to 6 amino acids from
any lysine present in said sequence, more preferably 5 to 6 amino
acids from any lysine present in said sequence, and having
immunoregulatory activity.
[0026] In a preferred embodiment of the present invention said
sequence contains a further glutamic acid at a distance of from 2
to 3 amino acids from said first glutamic acid.
[0027] In a preferred embodiment of the present invention the
peptide, peptide fragment, neo-structure and/or neo-epitope of
normal serum albumin has a peptide sequence selected from the amino
acid sequences listed as SEQ.ID.NO(s). 1-81.
[0028] In a preferred embodiment of the present invention said
sequence further contains an acidic amino acid at a distance of
-12.+-.1 amino acids from the first glutamic acid, and at a
distance of +3.+-.1 amino acids from the lysine.
[0029] A further aspect of the invention relates to a monoclonal
antibody directed against one or more of a protein sequence, such
as a peptide, peptide fragment, neo-structure and/or neo-epitope of
normal serum albumin having a first glutamic acid at a distance of
3 to 7 amino acids from any lysine present in said sequence,
preferably 4 to 6 amino acids from any lysine present in said
sequence, more preferably 5 to 6 amino acids from any lysine
present in said sequence, and having immunoregulatory activity.
[0030] In a preferred embodiment of the present invention the
antibody is directed against a peptide, peptide fragment,
neo-structure and/or neo-epitope of normal serum albumin
corresponding to one or more of the peptide sequences selected from
the amino acid sequences listed as SEQ.ID.NO(s). 1-81.
[0031] Another aspect of the invention relates to a method for
diagnosing the optional presence of an immunosuppressing cancer or
malignant tumour, by determining the presence of a peptide, peptide
fragment, neo-structure and/or neo-epitope of normal human serum
albumin having a first glutamic acid at a distance of 3 to 7 amino
acids from any lysine present in said peptide, peptide fragment,
neo-structure and/or neo-epitope, preferably 4 to 6 amino acids
from any lysine present in said peptide, peptide fragment,
neo-structure and/or neo-epitope, more preferably 5 to 6 amino
acids from any lysine present in said peptide, peptide fragment,
neo-structure and/or neo-epitope, and having immunoregulatory
activity, as shown in one or more standard immune tests/standard
tests on immune function, such as cytokine production, lymphocyte
proliferation, blocking binding of anti-integrin antibody to its
receptor.
[0032] Presently preferred sequences of a peptide, peptide
fragment, neo-structure and/or neo-epitope according to the present
invention are listed as follows:
TABLE-US-00001 SEQ. ID. NO. 1 EENFK SEQ. ID. NO. 2 EDHVK SEQ. ID.
NO. 3 ENCDK SEQ. ID. NO. 4 ETFLK SEQ. ID. NO. 5 ERAFK SEQ. ID. NO.
6 ECCEK SEQ. ID. NO. 7 ECYAK SEQ. ID. NO. 8 ERQIK SEQ. ID. NO. 9
EKCCK SEQ. ID. NO. 10 EEGKK SEQ. ID. NO. 11 EETFLK SEQ. ID. NO. 12
ETFLKK SEQ. ID. NO. 13 ETTLEK SEQ. ID. NO. 14 ETYVPK SEQ. ID. NO.
15 ERQIKK SEQ. ID. NO. 16 ELVKHK SEQ. ID. NO. 17 EVAHRFK SEQ. ID.
NO. 18 EVTEFAK SEQ. ID. NO. 19 ECFLQHK SEQ. ID. NO. 20 EETFLKK SEQ.
ID. NO. 21 ELLFFAK SEQ. ID. NO. 22 ELRDEGK SEQ. ID. NO. 23 EFAEVSK
SEQ. ID. NO. 24 EKPLLEK SEQ. ID. NO. 25 ESKDVCK SEQ. ID. NO. 26
EPQNLIK SEQ. ID. NO. 27 EQLGEYK SEQ. ID. NO. 28 EKERQIK SEQ. ID.
NO. 29 ESAENCDK SEQ. ID. NO. 30 EMADCCAK SEQ. ID. NO. 31 ECCQAADK
SEQ. ID. NO. 32 EGKASSAK SEQ. ID. NO. 33 EEPQNLIK SEQ. ID. NO. 34
EVSRNLGK SEQ. ID. NO. 35 EKERQIKK SEQ. ID. NO. 36 ELVKHKPK SEQ. ID.
NO. 37 ENQDSISSK SEQ. ID. NO. 38 EKCCKADDK SEQ. ID. NO. 39
ETCFAEEGK SEQ. ID. NO. 40 KDLGE SEQ. ID. NO. 41 KLVNE SEQ. ID. NO.
42 KQEPE SEQ. ID. NO. 43 KYLYE SEQ. ID. NO. 44 KVHTE SEQ. ID. NO.
45 KYICE SEQ. ID. NO. 46 KECCE SEQ. ID. NO. 47 KPLLE SEQ. ID. NO.
48 KNYAE SEQ. ID. NO. 49 KVFDE SEQ. ID. NO. 50 KPLVE SEQ. ID. NO.
51 KQNCE SEQ. ID. NO. 52 KCCTE SEQ. ID. NO. 53 KATKE SEQ. ID. NO.
54 KDLGEE SEQ. ID. NO. 55 KKYLYE SEQ. ID. NO. 56 KAAFTE SEQ. ID.
NO. 57 KAEFAE SEQ. ID. NO. 58 KPLVEE SEQ. ID. NO. 59 KEFNAE SEQ.
ID. NO. 60 KADDKE SEQ. ID. NO. 61 KTCVADE SEQ. ID. NO. 62 KLKECCE
SEQ. ID. NO. 63 KSHCIAE SEQ. ID. NO. 64 KCCKHPE SEQ. ID. NO. 65
KRMPCAE SEQ. ID. NO. 66 KQTALVE SEQ. ID. NO. 67 KPKATKE SEQ. ID.
NO. 68 KETCFAE SEQ. ID. NO. 69 KLVNEVTE SEQ. ID. NO. 70 KQEPERNE
SEQ. ID. NO. 71 KLDELRDE SEQ. ID. NO. 72 KTYETTLE SEQ. ID. NO. 73
KQNCELFE SEQ. ID. NO. 74 KKQTALVE SEQ. ID. NO. 75 KETCFAEE SEQ. ID.
NO. 76 KRYKAAFTE SEQ. ID. NO. 77 KDVCKNYAE SEQ. ID. NO. 78
KHKPKATKE SEQ. ID. NO. 79 EKDDAKCCK SEQ. ID. NO. 80
VFDEFKPLVEEPQNLIK SEQ. ID. NO. 81 VFDEFKPLVE
[0033] In the following the term "tissue" as used herein shall mean
whole blood, serum, plasma, lymphatic fluid, saliva, urine, faeces,
ascites, pleural effusion, pus, as well as any tissue, including
muscle, fat, and connective tissue, including inflammatory
cells.
[0034] In the present context, the term "protein sequence" is used
to describe one or more of a protein, polypeptide, peptide, peptide
fragment, neo-structure and/or neo-epitope that is generated as a
result of proteolytic fragmentation, denaturation and/or
conformational change(s) of a protein normally occurring in serum.
As is easily understood by the person skilled in the art, a
conformational change of a protein will of course not necessarily
always lead to its fragmentation, but might as well simply result
in the formation and/or presentation of a new structure and/or
epitope. In the present context several new structures and/or
epitopes are disclosed that are still attached to and presented by
the original protein normally occurring in serum.
[0035] A fragment of a protein normally occurring in serum is in
the present context defined as including fragments of proteins,
polypeptides and or peptides, without reference to a specific
length of said protein sequence.
[0036] In the present context, "denaturation" means any change of a
protein's structure from the normal, natural structure, such as for
example brought on by oxidative stress.
[0037] Proteins are biological macromolecules constituted by amino
acid residues linked together by peptide bonds. Proteins, as linear
polymers of amino acids, are also called polypeptides. Typically,
proteins have 50-800 amino acid residues and hence have molecular
weights in the range of from about 6,000 to about several hundred
thousand Dalton or more. Small proteins are called peptides,
oligopeptides or polypeptides. In the context of the present
invention, a "peptide" or "peptide fragment" for use in accordance
with the present invention, refers to a polypeptide which may be,
but is not limited to, being 5-50 amino acids in length, such as 5,
10, 15, 20, 25, 30, 35, 40, 41, 42, 43, 44, 45, 46, 47, 47, 48, 49
or 50 amino acids. Such peptides may also be longer than 50 amino
acids.
[0038] Furthermore, any amino acid sequence being at least 70%
identical, such as being at least 72%, 75%, 77%, 80%, 82%, 85%.
87%, 90%, 91%, 92%, 93%. 94%, 95%, 96%, 97%, 98%, or 99% identical
with the amino acid sequence of a peptide and/or peptide fragment
of a sequence as listed in SEQ.ID.NO: 1-81, according to the
invention, is also considered to be inside the scope of the present
invention.
[0039] By a peptide, peptide fragment, neo-structure and/or
neo-epitope having an amino acid sequence at least, for example 95%
identical to a reference amino acid sequence, is intended that the
amino acid sequence of e.g. the peptide is identical to the
reference sequence, except that the amino acid sequence may include
up to 5 point mutations per each 100 amino acids of the reference
amino acid sequence. In other words, to obtain a peptide having an
amino acid sequence at least 95% identical to a reference amino
acid sequence: up to 5% of the amino acids in the reference
sequence may be deleted or substituted with another amino acid, or
a number of amino acids up to 5% of the total amino acids in the
reference sequence may be inserted into the reference sequence.
These mutations of the reference sequence may occur at the amino
and/or carboxy terminal positions of the reference amino acid
sequence or anywhere between those terminal positions, interspersed
either individually among amino acids in the reference sequence or
in one or more contiguous groups within the reference sequence.
[0040] In the present invention, a local algorithm program is best
suited to determine identity. Local algorithm programs, (such as
Smith Waterman) compare a subsequence in one sequence with a
subsequence in a second sequence, and find the combination of
subsequences and the alignment of those subsequences, which yields
the highest overall similarity score. Internal gaps, if allowed,
are penalized. Local algorithms work well for comparing two
multidomain proteins, which have a single domain or just a binding
site in common.
[0041] Methods to determine identity and similarity are codified in
publicly available programs. Preferred computer program methods to
determine identity and similarity between two sequences include,
but are not limited to, the GCG program package (Devereux, J et al
(1994)) BLASTP, BLASTN, and FASTA (Altschul, S. F. et al (1990)).
The BLASTX program is publicly available from NCBI and other
sources (BLAST Manual, Altschul, S. F. et al, Altschul, S. F. et al
(1990)). Each sequence analysis program has a default scoring
matrix and default gap penalties. In general, a molecular biologist
would be expected to use the default settings established by the
software program used.
[0042] Results
[0043] Epitope Mapping with Mass Spectrometry of a Monoclonal Mouse
Antibody Specific for Denatured Human Serum Albumin (dHSA) Two
monoclonal antibodies directed against denatured HSA were shown to
have immunomodulatory activity. The structure of the epitope of one
of these mAbs was further investigated.
[0044] Two similar approaches for epitope mapping with
Matrix-Assisted Laser Desorption/Ionisation Time-of-Flight mass
spectrometry (MALDI-TOF ms) were used in order to define the
possible site/s on human serum albumin to which a mouse monoclonal
antibody specific for denatured albumin binds. One approach takes
advantage of the fact that tryptic peptides to which an antibody is
bound will not generate characteristic mass spectra in MALDI as
they are "hidden" from the analysis (3). Another approach takes
advantage of the fact that sites on a protein where an antibody has
bound are protected from proteolysis (1, 2).
[0045] Binding of Peptides Generated by Trypsination of dHSA by
Monoclonal Antibody A (mAb A)
[0046] Purified human serum albumin (HSA) was denatured with urea,
reduced with DTT and alkylated as described (4). The denatured HSA
was then subjected to trypsin treatment with a low concentration
(0.02-2 ng/ml) of trypsin. However, the spectra obtained with MALDI
were unsatisfactory, as the peptides masses typical for albumin
were not found. Based on gel electrophoresis this preparation
(digested by 0.02 ng/ml of trypsin) was found to contain
substantial amounts of undigested albumin. Therefore, trypsin
digestion was continued, at a higher concentration (5 .mu.g/ml) in
order to obtain the mass spectra usually used for identification of
proteins by MALDI.
[0047] Some of the now completely cleaved albumin solution was
incubated with the mAb A. MALDI-TOF ms was performed and spectra of
enzyme-treated denatured albumin obtained in the presence or
absence of mAb A were compared. Fourteen albumin massed were absent
or reduced after incubation with mAb A (Table 1 A, Column D). The
amino acid sequence of these peptides is shown in Table 1B. The
spectra represent multiple areas encompassing residues 66 to 508 of
the albumin molecule.
TABLE-US-00002 TABLE 1A Peptide residues of HSA binding to mAb A.
Column C: Peak area of peptides before adsorption with mAb A.
Column D: Peak area of peptides after adsorption with mAb A. Column
E: Peak area of peptides when digestion of dHSA was protected by
binding to mAb A C Peak area before D E A Antibody Peak area after
Peak area tryps. MH+ B incub. antibody incub. Albumin + antib.
(m/z) Residue 2 spectra 5 spectra 6 spectra 1149.67 066-075 1970,
4092 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1017.59 089-097 1695, 5089 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 933.56 098-105 1862, 4869 0, 0, 132,
0, 0 0, 0, 0, 0, 0, 0, 1434.65 106-117 809, 1010 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 927.55 162-168 6036, 13066 504, 118, 473, 448, 895,
216, 281, 288 724, 2346, 1571 1074.63 206-214 3064, 7917 0, 0, 0,
0, 0 0, 0, 0, 0, 0, 0 1443.74 287-298 583, 1394 0, 0, 0, 0, 0, 0,
0, 53, 0, 0, 0, 1546.91 299-310 2283, 4675 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 1311.84 362-372 1036, 1482 0, 0, 0, 0, 0, 0, 0, 51, 0, 407
(1312), 226 (1312) 1552.71 384-396 2186, 0027 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 1657.87 414-426 2519, 2978 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 212 (1656.64) 960.62 427-434 15276, 32846 267, 315, 931, 591,
1284, 199, 494, 309 1015, 2963, 1998 1138.56 500-508 1360, 4659 0,
0, 0, 0, 0, 0, 258, 0, 0, 0, 204 (1139) 1342.72 570-581 2720, 3758
0, 0, 0, 0, 0 0, 0, 0, 0, 0, 0
TABLE-US-00003 TABLE 1B Amino acid sequence of the peptide residues
of HSA bound by mAb A. MH+(m/z) Residue Sequence 1149.67 066-075
LVNEVTEFAK (SEQ ID NO: 104) 1017.59 089-097 SLHTLFGDK (SEQ ID NO:
84) 933.56 098-105 LCTVATLR (SEQ ID NO: 85) 1434.65 106-117
ETYGEMADCCAK (SEQ ID NO: 86) 927.55 162-168 YLYEIAR (SEQ ID NO: 87)
1074.63 206-214 LDELRDEGK (SEQ ID NO: 88) 1443.74 287-298
YICENQDSISSK (SEQ ID NO: 89) 1546.91 299-310 LKECCEKPLLEK (SEQ ID
NO: 90) 1311.84 362-372 HPDYSVVLLLR (SEQ ID NO: 91) 1552.71 384-396
CCAAADPHECYAK (SEQ ID NO: 92) 1657.87 414-426 QNCELFEQLGEYK (SEQ ID
NO: 93) 960.62 427-434 FQNALLVR (SEQ ID NO: 94) 1138.56 500-508
CCTESLVNR(SEQ ID NO: 95) 1342.72 570-581 AVMDDFAAFVEK (SEQ ID NO:
96)
[0048] In order to further confirm these results the monoclonal
antibody mAb A was allowed to bind to the denatured albumin
(previously digested by trypsin at a concentration of 0.02 ng/ml)
in order to protect the peptide sequences of the epitope. The
complex was then again treated with trypsin. MALDI-TOF ms was then
performed and the peptide mass spectra generated from albumin were
compared with spectra generated from denatured albumin
trypsin-treated in the absence of antibody. The same fourteen
masses out of 39 albumin masses disappeared completely or were
significantly reduced in the sample were the mAb was present during
trypsin treatment (Table 1 A, Column E). Multiple readings were
taken to verify the results.
[0049] Important peptide fragments might not be identified because
of the possibility that the mAb binding epitope of albumin is
cleaved by trypsin, resulting in fragments of the epitope with too
low binding affinity to bind to the mAb. Therefore, an alternative
method was also used.
[0050] MALDI epitope mapping of mAb A based on antibody protection
of proteolysis was repeated. This time a slightly different
approach was used. Denatured HSA was incubated with mAb A. Albumin
not bound by the antibody, was removed from the sample by size
exclusion on an ultra filter. The remaining free mabs and the
complexes of mab-albumin was then digested with trypsin (sequences
of the albumin molecule to which mab is bound should resist the
trypsin digestion). Small cleaved fragments of mab and unprotected
albumin was then removed from the sample by ultrafiltration (30
kD). The complexes of mAb and bound albumin fragments were
dissociated by lowering the pH to 2.7. Again ultrafiltration at 30
kD was performed to separate whole mAb from albumin fragments
smaller than 30 kD. MALDI TOF analysis of these fragments did not
identify spectra typical for albumin. Reasonably, because the
fragments containing the epitope of mAb A were still too large.
This filtrate (<30 kD) was then further digested with trypsin
(for cleavage of sites previously protected by the mAb) in order to
generate peptide masses suitable for analysis with MALDI TOF
ms.
[0051] After this second trypsin treatment, eight of 32 masses
detected by MALDI TOF ms matched to albumin (Table 2). Thus, these
now identified amino acid sequences comprise a part of the epitope,
which also contains sequences on the other side of the trypsin
cleavage point.
TABLE-US-00004 TABLE 2 Albumin peptides generated by trypsination
of larger fragments eluted from mAb A. Albumin Mass residue Peak
area Database sequence 875.49 243-249 481 LSQRFPK (SEQ ID NO: 97)
927.47* 162-168 1035 LYLEIAR (SEQ ID NO: 98) 933.51* 98-105 744
LCTVATLR (SEQ ID NO: 99) 940.41 131-138 534 DDNPNLPR (SEQ ID NO:
100) 960.55* 427-434 1345 FQNALLVR (SEQ ID NO: 101) 1074.52*
206-214 644 LDELRDEGK (SEQ ID NO: 102) 1138.47* 500-508 119
CCTESLVNR (SEQ ID NO: 103) 1149.53 66-75 1918 LVNEVTEFAK (SEQ ID
NO: 104) (1149.61)*
[0052] Six of the eight peptide masses (marked with* in Table 2)
were peptide masses that also disappeared when analysed previously
when completely cleaved albumin was incubated with the mAb A before
the MALDI-TOF analysis (Tables 1A and B).
[0053] The epitope/s of this antibody was thus established. It is
important to note that multiple such structures are present in the
albumin molecule, which can then cause cross-linking of the
receptors to which they are bound. A previous study into the
antigenicity of albumin, based on 13 different monoclonal
antibodies, has shown that intramolecular cross-reactivity exists
between different domains in human albumin (5), thus multiple
epitope sites for mAb A on albumin may be expected.
[0054] Based on these consistent results, a common pattern was
found. Glutamic acid was found at a distance of 5 or 6 amino acids
from lysine, either in the peptide sequences identified by
MALDI-TOF or in the sequence adjacent to the peptide sequence
identified by this technique (that is on the other side of the
trypsin cleavage point, at K (lysine), (Table 3)). It is
interesting to note that in 4 of these sequences an additional
glutamic acid was found at a distance of 2 or 3 amino acids from
the first glutamic acid residue. These additional glutamic acid
residues might be of importance for the affinity or signal
transduction of these peptides. The biological activity of these
peptides might also be influenced by the occurrence of acidic amino
acids both at a distance of 12.+-.1 amino acids (position -12) from
the first glutamic acid residue E (in the E5K structure) and at a
distance of 3.+-.1 amino acids (position +3) from the lysine
residue K (in the E5K structure. Due to the length of the two
important amino acids, glutamic acid (E) and lysine (K), in the
epitope of mAb A, the exact fixed distance between these amino
acids is not necessary for the immunoregulatory activity of these
fragments. Thus, a sequence of E3-7K can have immunoregulatory
activity similar to that of the E5K sequence (Table 4 A and B).
TABLE-US-00005 TABLE 3 Peptide sequences surrounding the E5K and
E6K structures selected for synthesis of peptides for testing of
immunological activity. One peptide with the E6K structure is
included in the table (sequence 2). Sequence 1 Residue D H V K L V
N E V T E F A K T C V A (SEQ ID 062-078 NO: 105) Mass MH+ (m/z)
1149.67 L V N E V T E F A K (SEQ ID NO: 104) E5K motif E V T E F A
K (SEQ ID NO: 18) Synthesized 2604 K L V N E V T E F A K T peptide
(SEQ ID NO: 106) Sequence 2 Residue T L R E T Y G E M A D C C A K Q
E P E R N E (SEQ ID 103-124 NO: 107) Mass MH+ (m/z) 1434.65 E T Y G
E M A D C C A K (SEQ ID NO: 139) E5K motif E M A D C C A K (SEQ ID
NO: 30) Synthesized 2607 E M A D C C A K Q E P E peptide (SEQ ID
NO: 108) Sequence 3 Residue F H D N E E T F L K K Y L Y E I A R R H
P (SEQ ID 151-171 NO: 109) Mass MH+ (m/z) 927.55 Y L Y E I A R (SEQ
ID NO: 98) E5K motif E E T F L K K (SEQ ID NO: 20) Synthesized 2605
N E E T F L K K Y L Y E peptide (SEQ ID NO: 110) Sequence 4 Residue
L L P K L D E L R D E G K A S (SEQ ID 202-219 NO: 111) Mass MH+
(m/z) 1074.63 L D E L R D E G K (SEQ ID NO: 136) E5K motif E L R D
E G K (SEQ ID NO: 22) Synthesized 2606 K L D E L R D E G K A S
peptide (SEQ ID NO: 112) Sequence 5 Residue Q N C E L F E Q L G E Y
K F Q N A L L V R Y T K (SEQ ID 414-437 NO: 113) Mass MH+ (m/z)
960.62 F Q N A L L V R (SEQ ID NO: 101) E5K motif E Q L G E Y K
(SEQ ID NO: 27) Synthesized 2608 E L F E Q L G E Y K F peptide (SEQ
ID NO: 114)
[0055] Five of these peptides were synthesized (Table 3) and their
immunoregulatory functions have been investigated. Based on these
studies it was postulated that both stimulatory and inhibitory
peptide sequences are present in serum albumin.
[0056] Conclusion--Epitope Mapping by MALDI-TOF MS
[0057] The Epitope of mAb A has been Identified as the E5-6K
Structure
[0058] The biologically relevant structure is thus E3-7K, possibly
with additional acidic amino acid residues at positions -12 and +3.
Taken together, these results indicate that mAb A can bind to
multiple regions of the albumin molecule. Since the experiments
were performed with denatured albumin, these epitopes are probably
not sites generated by combining residues when the molecule is
folded.
[0059] Binding Activity of E5K Peptides--Inhibition of mAb A
Binding to dHSA
[0060] In order to test the specificity of the synthesized
peptides, they were tested in an ELISA where inhibition of the
binding of mAb A to plates coated with dHSA was analysed. A high
binding of the antibody to the plate is thus consistent with no
inhibitory activity and this binding is reduced when an inhibitory
substance is added to the system. As shown in FIG. 1, four out of
five peptides showed a dose dependent inhibition of the antibody to
the dHSA coated plates, confirming that they contain a structure
reacting with the antibody.
[0061] Expression of the E5K Epitope in Tumour Cells--Correlation
to Survival
[0062] It has previously been demonstrated, by using
immunohistochemical staining with mAb A, that the E5K
epitope/structure is expressed by several types of cancer cells (WO
06/043891). A series of 20 biopsies from melanoma patients were
stained using this technique and the staining intensity was scored
from + to +++ using a light microscope. A considerable variation in
staining intensity was observed. Based on the most intensely
stained areas of the sections the patients were ranked from high to
low expressors of E5K. The number of patients was then divided into
two equal groups, high and low expressors, and a possible
difference in survival between these groups was analysed according
to Kaplan Meyer and a log rank analyses. As is shown in FIG. 2 a
highly statistically significant difference in survival was found
for high and low expressors.
[0063] Immunomodulatory Activity of E5K Peptides
[0064] Effect of Peptides on PHA Induced Proliferation of PBMCs
[0065] The effect of two albumin peptides, 2605 and 2608, on PHA
induced proliferation of PBMCs from one healthy control and two
cancer patients was tested. As shown in FIGS. 3 A and B, the
response pattern is quite different between individuals, presumably
due to the degree of immune stimulation of PBMCs in vivo and
possibly also due to the occurrence of auto-antibodies to the
neo-structures represented by the peptides. The importance of the
degree of immune stimulation is demonstrated by comparing the
effect of the peptides when the PBMCs are stimulated with either 5
or 10 .mu.g/ml of PHA (compare. FIGS. 3 A and B). In addition to
the inter-individual differences, also a biphasic response pattern
was found, for example using peptide 2605 with PBMCs from K92, the
lowest concentration was inhibitory, the middle concentration
stimulatory and again at the highest concentration, the
proliferative response was inhibited. It is also interesting to
note that a clear stimulatory activity was found with the lowest
concentration of both peptides in patient P46. There are also some
differences in the activity of the two tested peptides especially
when PBMCs are stimulated with PHA at a concentration of 5
.mu.g/ml. When a PHA concentration of 10 .mu.g/ml is used the
activity of the two peptides is similar. The culture model with the
lower degree of stimulation is of course more sensitive to
variation in the receptor binding structure. This example thus
demonstrates that once a biologically active peptide sequence has
been demonstrated, changes of the amino acid sequence can modulate
its biological activity.
[0066] To further analyse the inter individual differences in the
effect of these peptides PBMCs from healthy controls and 4 patients
were analysed (FIG. 4). PHA was used at a concentration of 5
.mu.g/ml and the peptides at a concentration of 10 .mu.g/ml. Again
a clear difference between individuals was demonstrated. Peptide
2605 had an inhibitory or stimulatory effects in one control each
and one patient each. Peptide 2608 had a stimulatory effect in 1/4
controls whereas 3/4 patients were stimulated.
[0067] Effect of dHSA on PHA Induced Proliferation of Peripheral
Blood Mononuclear Cells (PBMCs)
[0068] The effect of dHSA on PHA induced proliferation of PBMCs
from healthy controls and cancer patients is quite variable (FIG.
5). Again this can be due to the degree of stimulation of PBMCs in
vivo and possibly also to the presence of auto-antibodies against
dHSA. Addition of dHSA to these cultures can result both in
stimulation and inhibition of the proliferative rate, but
frequently resulted in stimulation of the proliferative rate. It is
remarkable that one control did not respond at all and this person
did not respond to a higher concentration of PHA either. In one
patient (P41) addition of dHSA inhibited proliferation, especially
at a PHA concentration of 10 .mu.g/ml. The variation in response
between patients, demonstrates the need of diagnosing the
individual immune status of cancer patients.
[0069] Effect of Peptides on dHSA Modulated PHA Induced
Proliferation of PBMCs
[0070] Next the effect of different peptides, 2605 or 2608, on dHSA
enhanced PHA induced proliferation was analysed. As shown in FIGS.
6 A and B addition of dHSA at a concentration of 8 .mu.g/ml
significantly increased the proliferative rate of PHA stimulated
PBMCs from two different healthy controls. At the lower
concentrations of dHSA, the stimulatory activity declined.
Interestingly, addition of the peptides at a concentration of 10
.mu.g/ml significantly inhibited the stimulatory activity of the
two highest dHSA concentrations, whereas at the lower
concentrations the peptides to the contrary stimulated the
proliferative rate. Thus, the stimulatory effect of dHSA at 8n g/ml
was inhibited by addition of the peptides, but the same
concentration of the peptides stimulated the proliferative rate at
a lower concentration of dHSA. Reasonably, cross-linking of the E5K
receptor is involved in the stimulatory activity of dHSA as
monomeric binding of the peptides to this receptor inhibits the
stimulatory effect of dHSA. The same concentration of the peptides
then has quite different activity in the presence of different
concentrations of dHSA, at 0.8 .mu.g/ml there is still a slight
inhibitory activity whereas at the lower concentrations of dHSA the
proliferative rate is significantly enhanced. A reasonable
explanation to this is that the stimulatory activity of the
peptides is blocked by an inhibitory neo-structure of albumin at
dHSA concentration of 8 .mu.g/ml.
[0071] Effect of Peptides on Monokine Production by PBMCs
[0072] The effect of albumin peptides, 2604-2608, on LPS induced
IL-6 production is shown in FIG. 7 A-C. Again, considerable
inter-individual differences in the activity of the peptides are
observed. Analysing PBMCs from one healthy control, peptide 2604
was stimulatory at the lowest concentration, whereas peptides 2606
and 2608 at this concentration were inhibitory (FIG. 7A). The
activity also varied between the two melanoma patients, but in one
of these patients all peptides had a stimulatory activity (FIG. 7
C).
[0073] Thus all five peptides have immunomodulatory activity, but
the effect varies depending the immune status of the investigated
individual.
[0074] Effect Albumin Peptides on Immunohistochemical Staining of
PBMC Using an Anti-Integrin Antibody
[0075] The immunobiological importance of albumin amino acid
sequences was further studied by analysing their influence on the
binding of a monoclonal antibody to the f-integrin LFA-1 (CD11a) on
immune cells (FIG. 8 A-F). This molecule was chosen for these
experiments, as it is known that binding of certain mAb's to this
molecule seriously can modulate/inhibit functions of the immune
system. The particular antibody chosen for these experiments has
been shown to inhibit the binding of LFA-1 to ICAM-1 AND
ICAM-3.
[0076] Cytospin preparations of mononuclear blood cells from
healthy controls, cancer patients and a monocytic cell line, THP-1,
were prepared (as described under materials and methods), dried and
stored at -70.degree. C. In the immunocytological staining,
unspecific staining was blocked by incubation with 10% human AB
serum. Some of the slides were preincubated for 60 minutes with
albumin peptides at a concentration of 40 .mu.g/ml, added to this
10% AB serum, as indicated in the FIG. 8 A-F. The staining
procedure was then continued as described in material and methods.
The staining intensity of slides stained with and without
preincubation with the peptides was recorded semi quantitatively
using a standard light microscope.
[0077] As shown in FIG. 8 A-F, binding of the mAb to LFA-1 can be
inhibited by preincubation with the peptides. As mentioned in other
sections of this document, the immune status of the donor of blood
cells might influence the outcome of immunological analyses.
Accordingly, the stainability of PBMCs from some donors seems to be
uninfluenced by pre-incubation with the peptides and in a few cases
with low initial stainability even enhanced staining was observed.
The binding of the mAb to LFA-1 to the monocytic cell line THP-1
was clearly enhanced by pre-incubation with peptide 2606 (FIG. 8 A,
B). These results clearly show that the structure of E5K interact
with the .beta.2-integrin in a way, which is of importance for the
function of the immune system.
[0078] Binding of Peptides Generated by Trypsination of dHSA by
Cell Surface Receptors
[0079] Based on the observation that immunoregulatory peptide
sequences are present in serum albumin, there is the possibility
that other sequences than the epitope of mAb A have
immunoregulatory function. Therefore an artificial cell surface
(ACS) was prepared as described in materials and methods. The
mixture of peptides obtained after trypsination was adsorbed by ACS
and the binding peptides were identified by comparing adsorbed and
unadsorbed peptide solutions using the MALDI TOF ms technique.
These peptides are shown in Table 5 A.
TABLE-US-00006 TABLE 5 A Peptides generated by trypsin degradation
of dHSA and the degree of adsorption to the receptors of ACS. The
amino acids within brackets show the protease cleavage point and
are not included in the identified masses. ACS adsorbed peptides
Synthesized E5K peptides Per cent Start E5K Start adsorbed Sequence
End Peptide Sequence End 0.71 (K)KYLYEIAR(R) (SEQ ID 161-168 2605
153-168 NO: 115) 0.64 (K)KVPQVSTPLVEVSR(N) 438-452 (SEQ ID NO: 116)
0.60 (K)VFDEFKPLVEEPQNLIK 397-413 (Q) (SEQ ID NO: 193) 0.59
(K)VPQVSTPTLVEVSR(N) 439-452 EMADCCAKQEPE (SEQ ID NO: 142) (SEQ ID
NO: 108) 0.42 (R)RPCFSALEVDETYVPK 509-524 (E) (SEQ ID NO: 119) 0.41
(K)FQNALLVR(Y) (SEQ ID 427-434 NO: 101) 0.36 (K)SLHTLFGDK(L) (SEQ
ID 89-97 ELFEQLGEYKF NO: 84) (SEQ ID NO: 114) 0.36
(K)LKECCEKPLLEK(S) 299-310 EMADCCAKQEPE (SEQ ID NO: 122) (SEQ ID
NO: 108) 0.35 (K)LCTVATLR(E) (SEQ ID 98-105 NO: 85) 0.34
(K)YLYEIAR(R) (SEQ ID 162-168 2605 153-168 NO: 115) 0.32
(K)CCAAADPHECYAK(V) 384-396 (SEQ ID NO: 125) 0.29
(K)AAFTECCQAADK(A) 187198 KLDELRDEGKAS (SEQ ID NO: 126) (SEQ ID NO:
112) 0.26 (K)CCTESLVNR(R) (SEQ 500-508 ID NO: 127) 0.26
(K)QEPERNECFLQHK(D) 118-130 2607 KLVNEVTEFAKT 110-122 (SEQ ID NO:
132) (SEQ ID NO: 106) 0.23 (K)AVMDDFAAFVEK(C) 570-581 (SEQ ID NO:
129) 0.22 (R)NECFLQHK(D) (SEQ ID 123-130 NO: 130) 0.20
(K)QNCELFEQLGEYK(F) 414-426 2608 417-427 (SEQ ID NO: 144) 0.18
(K)QEPERNECFLQHK(D) 118-130 2607 110-122 (SEQ ID NO: 132) 0.13
(K)VHTECCHGDLLECADDR 265-281 (A) (SEQ ID NO: 133) 0.08
(R)FKDLGEENFK(A) (SEQ 35-44 EMADCCAKQEPE ID NO: 134) (SEQ ID NO:
108) 0.03 (K)YICENQDSISSK(L) (SEQ ID NO: 135) 287-298 0.02
(K)LDELRDEGK(A) (SEQ ID 206-214 2606 205-217 NO: 136) 0.01
(K)DDNPNLPR(L) (SEQ ID 131-138 ELFEQLGEYKF NO: 137) (SEQ ID NO:
114) -0.02 (K)LVNEVTEFAK(T) (SEQ 66-75 2604 EMADCCAKQEPE 65-76 ID
NO: 138) (SEQ ID NO: 108) -0.08 (R)ETYGEMADCCAK (Q) 106-117 (SEQ ID
NO:139) -0.37 (R)YKAAFTECCQAADK(A) 185-198 (SEQ ID NO: 140)
[0080] Based on their degree of binding and their spatial relation
to the E5K structures of albumin, four new peptides were selected
to be synthesized and investigated for their immunoregulatory
activity (Table 5 B).
TABLE-US-00007 TABLE 5B ACS adsorbed peptides Synthesized albumin
peptides Per ent Start Adsorbed Sequence Start End Peptide Sequence
End 0.71 (K)KYLYEIAR(R) (SEQ 161 168 3026 NEETFLKKYLYEIARRHPYFYA
153-176 ID NO: 115) P (SEQ ID NO: 145) 0.64 (K)KVPQVSTPTLVEVSR 438
452 3029 KVPQVSTPTLVEVSR (SEQ ID 438-452 (N) (SEQ ID NO: 116) NO:
146) 0.60 (K)VFDEFKPLVEEPQNLI 397 413 3028 VFDEFKPLVEEPQNLIK (SEQ
397-413 K(Q) (SEQ ID NO: 117) ID NO: 117) 0.20 (K)QNCELFEQLGEYK(F)
414 426 3027 ELFEQLGEYKFQNALLVR 417-434 (SEQ ID NO: 144) (SEQ ID
NO: 147) Related E5K peptide 2605 (3026) NEETFLKKYLYE (SEQ ID
153-168 NO: 110) Related E5K peptide 2608 (3027) ELFEQLGEYKF
417-427 (SEQ ID NO: 114)
[0081] Immunomodulatory Activity of Peptides Generated by
Trypsin
[0082] Effect of peptides on dHSA modulated PHA induced
proliferation of PBMCs Two of the peptides in the new series, 3026
and 3028, were tested and compared to peptide 2605 in an analysis
for their effect on dHSA modulated PHA stimulated proliferation
(FIG. 9). PHA induced proliferation of PBMCs from two healthy
controls was further stimulated by dHSA. As shown in FIG. 9, all
peptides inhibited the stimulatory activity of dHSA at the two PHA
concentrations used. Also in this experiment, the degree of
stimulation of PBMCs has an impact on the results.
[0083] Effect of Peptides on Interleukin-2 Induced Proliferation of
PBMCs
[0084] The peptides of the new series, 3026-3029, were also tested
for their effect on IL-2 induced proliferation. As shown in FIG. 10
A, 3/4 peptides, 3026, 3027 and 3029, had no statistically
significant activity. In contrast, peptide 3028 was highly
inhibitory (p=0.005). It is interesting to note that this
inhibitory effect was completely reversed by modulation of the
Fc-receptor cross-linking (FIG. 10 B) similar to the situation
previously described for IL-2 related immunosuppression in renal
cell carcinoma (WO 03/099312 A1).
[0085] Effect of the New Series of Peptides on Monokine Production
by PBMCs
[0086] The effect of the new series of peptides showed a
considerable difference in effect even between healthy control
individuals (FIG. 11). Peptide 3026 had no certain effect in one of
the controls (PBMC 2), but had a clear biphasic effect in the other
(PBMC1). In the latter case, the IL-6 production was stimulated at
the three highest concentrations and was clearly inhibited at the
lowest concentration. Peptide 3027 was slightly stimulatory in one
of the controls and had an inhibitory effect in the other. Similar
results were also found with peptide 3028. Peptide 3029 had a
slight stimulatory effect in only one of the controls, at the two
highest concentrations. It is interesting to note that all peptides
except 3029 had an immunomodulatory effect at a concentration as
low 10 ng/ml. Thus, all peptides had an effect in at least one of
the analysed controls.
[0087] Similar to the effect of the new series of peptides on PBMC
from healthy controls, also PBMC from cancer patients showed
considerable inter-individual differences (FIG. 12). Peptides 3026
and 3027 both had a stimulatory effect in the renal cell carcinoma
patient and in addition peptide 3027 also stimulated one of the
melanoma patients. The other two peptides, 3028 and 3029, had
essentially no effects in these tests. In contrast to the situation
in the controls, no inhibitory effects were seen.
[0088] Binding of Peptides Generated by Asparaginase Degradation of
dHSA by Cell Surface Receptors
[0089] The full peptide sequence of albumin is not recovered using
the MALDI-TOF technique after trypsin degradation. In addition,
some sequences with the capacity to bind to cell surface receptors
of immune cells, might have been degraded by trypsin treatment.
Therefore, the same experimental procedure as described above was
used also for a peptide mixture obtained by degradation using
asparaginase. The resulting ACS binding peptides are shown in Table
6 A and B.
[0090] In addition to the peptides generated by trypsin degradation
another six peptides with a molecular weight of 700-3600 Da were
found to be efficiently adsorbed (.gtoreq.65%) by the cell surface
structures on the ACS column (Table 6A)
TABLE-US-00008 TABLE 6 A Per ent Start Adsorbed Sequence End 1.00
DHVKLVNEVTEFAKTCVA (SEQ ID NO: 105) 62-79 1.00
DDKETCFAEEGKKLVAASQAALGL (SEQ ID NO: 151) 586-609 0.87
DRVTKCCTESLVNRRPCFSALEV (SEQ ID NO: 152) 495-517 0.86
DETYVPKEFNAETFTHA (SEQ ID NO: 153) 518-535 0.65
DSISSKLKECCEKPLLEKSHCIAEVEN (SEQ ID NO: 154) 293-319 0.65
DKLCTVATLRETYGEM (SEQ ID NO: 155) 96-112
[0091] Seven peptides of a molecular weight between 3200 and 9000
Da were found to be completely adsorbed by ACS and for one of the
peptides of this group, 37% was bound. In this analysis another 9
peptides were not at all bound by ACS.
TABLE-US-00009 TABLE 6 B ACS Adsorbed ASP-DHSA Per cent adsorbed
Sequence Start End 1.00 YSVVLL LRLAKTYETT LEKCCAAADP HECYAKVF (SEQ
ID 364-398 NO: 156) 1.00 KLCT VATLRETYGE MA DCCAKQEP ERNECFLQHK
(SEQ ID 96-130 NO: 157) 1.00 ICTLSEKERQIKKQ TALVELVKHK PKATKEQLKA
VM (SEQ ID 536-572 NO: 158) 1.00 LAKYICE NQDSISSKLK ECCEKPLLEK
SHCIAEVEN (SEQ ID 283-319 NO: 159) 1.00 VF LGMFLYEYAR RHPDYSVVLL
LRLAKTYETT LEKCCAAA 348-388 (SEQ ID NO: 160) 1.00 LGE ENFKALVLIA
FAQYLQQCPF EDHVKLVNEV TEFAKTCVA 37-79 (SEQ ID NO: 161) 1.00 RVTKC
CTESLVNRRP CFSALEVDET YVPKEFNAET FTFHA 495-535 (SEQ ID NO: 162)
0.37 YLSVVLNQLCVLHEK TPVS DRVTKC CTESLVNRRP CFSALEV 475-517 (SEQ ID
NO: 163)
[0092] Two peptides in this group did not bind at all and for one
peptide (SISSKLKECCEKPLLEK SHCIAEVEN DEMPA) (SEQ ID NO:195)
contradictory results were obtained regarding adsorption by
ACS.
[0093] Thus, asparaginase treatment generates peptide sequences
other than those generated by trypsin, which efficiently bind to
cell surface structures of immune cells. Based on results described
above these structures will most likely have an immunomodulating
activity.
[0094] Occurrence of ACS Binding Fragments of IgG in Cancer
Patients
[0095] In order to further identify the occurrence of immune cell
binding structures in vivo, blood plasma was prepared and affinitiy
chromatography was performed as described above. The substances
bound by the ACS column were eluted, fractionated on 2D
gel-electrophoresis and identified using the MALDI TOF technique.
As expected the areas of the 2D gel corresponding to albumin and
immunoglobulins were identified. In addition, other immune cell
binding substances were also identified (FIG. 13). The binding of
some variety of albumin, presumably damaged albumin carrying
conformational changes, to immune cells has been previously
described by several groups. The new immune cell binding structures
found in this investigation are summarized in Table 7.
TABLE-US-00010 TABLE 7 Proteins identified by MALDI-TOF ms. 1. IgA
heavy chain variable region Acc. #: 3004672 2. Immunoglobulin heavy
chain variable and Acc. #: 2198477 joining regions 3.
Immunoglobulin heavy chain Acc. #: 1669777 Ig heavy chain V region
(clone LUNm03) Acc. #: 484974 4 SERTA domain-containing protein 2
Acc. #: Q14140 (TRIP-Br2) 5. Immunoglobulin heavy chain variable
region Acc. #: 42632530
[0096] Thus, besides serum albumin also other normally occurring
proteins are substrates for generation of immunoregulatory
fragments.
[0097] Thus it can be concluded and as it is clearly shown in the
present patent application that sequences of normally occurring
proteins such as serum albumin and IgG bind to cell surface
receptors of immune cells and have immunoregulatory activity. Both
stimulatory and inhibitory sequences have been identified. In
addition, cross-linking of receptors on immune cells was found to
be one mechanism whereby the function of these cells can be
modulated.
[0098] Human Ex Vivo Model for Evaluation of Immunosuppression in
Cancer Patients
[0099] IL-2 is of fundamental importance for initiation and
stimulation of an immune response and the activity of this cytokine
is often inhibited in cancer related immunosuppression. Therefore,
a human ex vivo model for immunosuppression in cancer patients
(FIGS. 14 and 15) was set up for evaluation of possible inhibitory
immunoregulatory peptides.
[0100] The response to IL-2 in this model was demonstrated to
correlate to over-all survival of the patients (FIG. 15).
Immunosuppression in this human ex vivo model is mediated by serum
factors, as the proliferative capacity of PBMCs from healthy
controls is significantly inhibited if these cells are cultured
with cancer patient sera in the medium (FIG. 16).
[0101] Identification of Additional Immunoregulatory Peptides
[0102] Artificiell cell surface columns (ACS) were used in order to
identify peptide sequences from albumin binding to immune cell
surface receptors. After biotinylation, such receptors were bound
to streptavidin beads. Peptides binding to such columns were after
elution identified by the MALDI-TOF technique. Based on these
results and their relation to previously identified albumin
peptides, five peptides were synthesized. Their immunoregulatory
activity was primarily tested on the response to IL-2.
[0103] The effect of different peptides on IL-2 induced
proliferation was analysed in the human ex vivo model. The 3028
peptide regularly inhibits IL-2 induced proliferation, but none of
the other peptides identified by their binding to the artificial
cell surface had any inhibitory activity (FIG. 17). As the
C-terminal part of peptide 3028 contains a previously identified
immunoregulatory structure, E5K, the effect of five peptides
containing this structure was also tested on IL-2 induced
proliferation, but these showed only a minimal or no inhibitory
activity.
[0104] The inhibitory activity of peptide 3028 on IL-2 induced
proliferation can be demonstrated also in cultures with cancer
patient PBMCs, even if the response to IL-2 was already suppressed
(FIG. 18) As immunosuppression in cancer is characterized by a poor
response to IL-2, inhibition of the activity of this albumin
neo-structure in cancer patients has a great capacity to overcome
cancer related immunosuppression. This peptide inhibits one of the
fundamental mechanisms in initiation and up-regulation of an immune
response, it will therefore most likely be of great value in
down-regulation of the immune reactivity in chronic inflammatory
and auto-immune diseases.
[0105] Further Characterization of the Effect of Peptide 3028 on
IL-Induced Proliferation
[0106] As certain albumin neo-structures have previously been found
to have immunomodulatory activity and the C-terminal part of
peptide 3028 has a similar structure, the C- and N-terminal parts
of peptide 3028 were synthesized and analyzed separately and in
combination. Obviously the inhibitory activity of the two parts of
peptide 3028 is much weaker (FIG. 19).
[0107] Characterization of a Rabbit Antiserum and Affinity Purified
Rabbit Antibodies Directed Against the 3028 Peptide
[0108] Rabbit antisera directed against the albumin peptide 3028
Binds to dHSA and to a lesser extent to kHSA. Two antisera, R and
L, from two different rabbits were tested. These serum antibodies
bind preferentially to the 3325 but not to the 3218 fragment of
3028. Similar results are also obtained with the affinity purified
antibodies (see FIG. 21).
[0109] Immunomodulatory Effect of Affinity Purified Rabbit
Antibodies Directed Against the 3028 Peptide
[0110] As shown in FIG. 22, inhibition of the proliferative
response to IL-2 was over-come in immunosuppressed cancer patients
(FIG. 22A) and normal controls with down-regulation of the immune
reactivity (FIG. 22 B) having a proliferative rate of less than 100
000 dpm in the human ex vivo model. The anti-3028 antibodies had no
effect when the proliferative rate is in the normal range.
[0111] Polyclonal rabbit IgG was added to control cultures in order
to make sure that the effect of the affinity purified antibodies
was not due to an unspecific activity of rabbit IgG in this model.
Rabbit IgG had only minimal activity. The specificity of the
anti-3028 antibodies was further demonstrated as the stimulatory
effect of these antibodies was neutralized by a small amount of
peptide 3028 having no inhibitory activity per se. In addition
adsorption of inhibitory sera by gel to which anti-3028 antibodies
were bound reduced the inhibitory activity of such sera.
[0112] Similar to the results in the autologous ex vivo model the
immunosuppressor activity of sera from persons with a low
proliferative response to IL-2 was over-come by addition of the
anti-3028 antibodies to the cultures.
[0113] Binding of Anti-3028 Antibodies to/Expression of the 3028
Epitope in/Malignant Tumours
[0114] Structures to which anti-3028 antibodies bind are widely
expressed in human malignant tumours, e.g. malignant melanoma,
renal cell carcinoma and colorectal cancer (see FIG. 23).
[0115] The Receptor of Peptide 3028:
[0116] Binding of 3028 to LFA-1
[0117] Similar to the results described above for cancer patients
sera and the previously identified immunoregulatory peptides the
3028 peptide have the capacity to modulate the binding of the LFA-1
antibody (HI 111) to LFA-1 of mononuclear blood cells. Both
inhibition (FIG. 24) and enhancement of the binding have been
demonstrated, reasonably depending on the structure of LFA-1
(activated or inactivated form) when the cytospin preparations of
the cells were prepared. Also the C- and N-terminal parts of this
peptide has been shown to have some inhibitory activity (FIG.
24).
[0118] In agreement with these results and the effect of the 3028
peptide on IL-2 induced proliferation, it is of quite some interest
to note that the anti-LFA-1 antibody used in these experiments is a
potent inhibitor of IL-2 induced proliferation. Similar results
have previously been published by Vyth-Dreese et al. (1993).
[0119] Binding of 3028 to the .alpha.-Chain (CD25) of the IL-2
Receptor
[0120] As peptide 3028 significantly inhibits the proliferative
response to IL-2, the amino acid sequence of this peptide was
compared to that of IL-2 and certain similarities were found at the
receptor binding site of IL-2 (Table 8).
TABLE-US-00011 TABLE 8 Homologies in amino acid sequence of albumin
peptide 3028 and a segment of human interleukin- 2, which
participate in the interaction of interleukin-2 with interleukin-2
receptor alpha (CD25). Peptide 3028 V F D E F K P L V E E P Q N L K
(SEQ ID NO: 117): Human IL-2 E L K P L E E (SEQ ID NO: 194): (a.a.
61-72)
[0121] Based on this observation, the effect of peptide 3028 on the
binding of IL-2 to CD25 was studied. The fusion protein of CD25 and
the Fc-part of IgG was bound to protein G coated micro-plates/ELISA
plates and the plates were incubated with biotinylated IL-2 with or
without peptide 3028 present. Amazingly, the binding of IL-2 to
CD25 was enhanced by peptide 3028, indicating a three-part
interaction between IL-2, CD25 and 3028. Even if the binding of
IL-2 to CD25 is enhanced the proper assembly of the high affinity
receptor and/or signal transduction is blocked as peptide 3028 is a
potent inhibitor of IL-2 induced proliferation (see above).
[0122] Next, it was demonstrated using computer assisted molecular
modeling that peptide 3028 binds to CD25 at the IL-2 binding site
(FIG. 25). It can thus be concluded that peptide 3028 has a dual
immunoregulatory capacity by binding both to LFA-1 and the IL-2
receptor.
[0123] Peptide 3028, Optimal Immunosuppressive Structure:
[0124] The Physiological Inhibitory Peptide
[0125] Based on the results described above (difference in
anti-proliferative activity of peptides 3218 an 3325, specificity
of the affinity purified antibodies directed to peptide 3325 and
not to peptide 3218, immunomodulatory activity these antibodies,
and the effect of these peptides on the binding of the anti-LFA-1
mAb to immune cells) it can be concluded that neither of the minor
peptides, 3218 or 3325, are as efficient as the complete peptide,
3028 (FIG. 26). However, both peptides inhibit the binding of mAb
HI 111 to LFA-1. One reasonable explanation to this is that both of
the minor peptides contribute to the full activity of the
inhibitory effect of peptide 3028. It is thus logic to extend
peptide 3325 with the N-terminal amino acids of peptide 3218. As
the C-terminal extension of peptide 3325 is a lysine it would be of
quite some interest to produce longer peptides in order test the
possibility that the longer peptides are even more efficient than
peptide 3028.
[0126] In order to maintain the physiological nature of this
inhibitory peptide, the only relevant modifications of its
structure is to change its length as discussed above.
[0127] This program will thus clarify the optimal structure of
peptide 3028 to be used as an immunosuppressive drug for treatment
of IL-2 related/dependent pathological conditions/diseases such as
T-cell malignancies, allograft rejection of organ transplants,
graft versus host disease (GVH), chronic inflammatory diseases such
as psoriasis and some autoimmune diseases. The rational for the
therapeutic use the immunoinhibitory peptide 3028 in these
conditions is demonstrated by the therapeutic activity of
monoclonal antibodies directed against CD25 (the Tac-recptor)
TABLE-US-00012 TABLE 9 3028 3325 3218 PHEC VFDEFKPLVE (SEQ LIK (SEQ
ID ELFEQ ID NO: 81) NO: 172) Some antiproliferative Some
antiproliferative activity activity Weak binding to LFA-1 Weak
binding to LFA-1 Binds to affinity Does not bind to affinity
purified antibodies purified antibodies
[0128] Comments on the Present Immunoregulatory Mechanism
[0129] As immunosuppression in cancer is characterized by a poor
response to IL-2, inhibition of the activity of this albumin
neo-structure in cancer patients have a great capacity to overcome
cancer related immunosuppression. This peptide inhibits one of the
fundamental mechanisms in initiation and up-regulation of an immune
response, it will therefore most likely be of great value in
down-regulation of the immune reactivity in chronic inflammatory
and auto-immune diseases.
[0130] The immunoregulatory 3028-structure described in the present
patent application is generated by a physiological mechanism
present in inflammation and cancer. Therapeutic strategies based on
these targets will therefore be generally applicable.
[0131] Based on current data the mechanism of action is species
specific therefore analogous animal models are not applicable.
Proof of concept is obtained in a human ex vivo model where the
results correlates to over-all survival of cancer patients
[0132] Antibodies Specific for Albumin Peptide 3028 for Therapeutic
Use
[0133] Antibodies, full-length or fragments, with specificity for
3028, as well as for any of the fragments disclosed in
SEQ.ID.NO(s). 1-81, should preferably be either humanized or fully
human for therapeutic applications. Such antibodies can be produced
utilizing a number of established technologies.
[0134] To humanize an animal (e.g. mouse) monoclonal antibody,
recombinant approaches are used to graft the complementary
determining regions (CDRs) from an animal-derived hybridoma
immunoglobulin cDNA to the corresponding regions of a matched human
immunoglobulin cDNA. The resulting recombinant antibody can then be
expressed and produced in a variety of organisms, f.ex. bacteria or
mammalian cell lines.
[0135] Fully human antibodies can be obtained primarily through
three different approaches; 1) by rescuing naturally occurring
antibodies from immune human donors through Epstein Barr virus
(EBV) transformation of B cells or through PCR-cloning and phage
display. 2) by immunizing and producing hybridomas from transgenic
mice, which have been created with a repertoire of human
immunoglobulin germline gene sequences. 3) by screening synthetic
phage libraries containing human antibody variable (V-) region
genes and selecting antigen-binding V-regions through phage
display. The selected antibody is then cloned.
[0136] There are now multiple commercial companies that develop
human antibodies towards a defined protein/peptide on a for-fee
basis. In addition, new "antibody-like" molecules (f.ex.
anticalins, affilin, affibodies) are rapidly being developed and
produced as potential drug candidates. (For a review, see for
example: Peterson N C. Advances in monoclonal antibody technology:
Genetic engineering of mice, cells and immunoglobulins. ILAR
Journal, 2005, 46:314-9.)
[0137] Effect of Albumin Peptides on Cytotoxic Activity of Natural
Killer (NK) Cells from Healthy Blood Donors
[0138] Results
[0139] The NK cytotoxic activity of blood mononuclear cells from
four healthy donors were tested. As seen in figure XX, the presence
of peptide 3028 and, to a lesser degree, peptide 3026 reduced the
percent specific lysis of K562 target cells by all four donors.
Inhibition was not seen in the presence of peptide 3027,
however.
[0140] Materials and Methods
[0141] Preparation of Denatured Human Serum Albumin (dHSA)
[0142] Human serum albumin (HSA) infusion solution (Pharmacia,
Uppsala, Sweden) was denatured and reduced by resuspending it at a
final concentration of 10 mg/ml in 8 M urea and 10 mM
dithiothretiol (both from Sigma Chemical Co, St. Louis, Mo.) in 50
mM Tris-HCL (pH 7.9) for 2 h at 25.degree. C. The HSA was then
alkylated by the addition of 60 mM iodoacetamide (Sigma) and
further incubated for 2 h at 25.degree. C. in the dark. The HSA
solution was diluted to a concentration of 100 ug/ml with phosphate
buffered saline (PBS, Gibco BRL) and dialyzed extensively against
PBS using Spectrapore 4 dialysis tubing with a cut-off of mw 12000
(Spectrum Europe, Breda, The Netherlands). Control HSA was prepared
in parallel by incubating HSA at 10 mg/m in Tris-HCL (pH 7.9)
followed by dialysis. Before use in tissue culture experiments the
dHSA was sterile filtered through a 0.22 .mu.m syringe filter
(Millipore Co, MA, USA). DHSA was either stored at 4.degree. C. or
freeze dried and stored at -20.degree. C.
[0143] Enzymatic Cleavage of dHSA with Low-Dose of Trypsin
[0144] Buffer exchange to 25 mM NH.sub.4HCO.sub.3, pH 8, was
performed on denatured HSA with Sephadex-G25 gel filtration (PD-10
desalting columns, Amersham Biosciences Europe. Uppsala, Sweden).
Protein exchange was determined with Bio-Rad protein assay based on
the Bradford dye-binding procedure following the manufacturer's
recommendations (Bio-Rad Laboratories AB, Sundbyberg, Sweden).
Sequencing grade modified trypsin (Promega, Madison, concentration
after buffer WI) was added at a final concentration of 2, 0.2 or
0.02 ng/ml to denatured HSA (49 ug/ml). Alternatively, as a
control, the equivalent amount of trypsin dilution buffer (50 mM
C.sub.2H.sub.4O.sub.2) was added. The mixture was incubated at
37.degree. C. for 18 hours. Trypsin activity was stopped by passage
of the sample over a column with soy bean trypsin inhibitor
cross-linked to CNBr activated agarose (Sigma).
[0145] Complete Enzymatic Cleavage of dHSA with High Dose Trypsin
Followed by Incubation with mAb A for Epitope Mapping
[0146] Eight .mu.g of low-dose trypsin-treated dHSA was freeze
dried and then dissolved in 16 .quadrature.l of sequencing grade
modified trypsin (at 5 .mu.g/ml) (Promega) and incubated at
37.degree. C. for 18 hours. A portion (10 .mu.l) of the tryptic
digested peptides was reacted with the monoclonal antibody (mAb A)
at a final concentration of 0.3 mg/ml for 2 hours at room
temperature. The samples were stored at 4.degree. C. over night and
then analysed by MALDI TOF MS (see below).
[0147] Incubation of dHSA with mab Followed by Complete Enzymatic
Cleavage with Trypsin for Epitope Mapping
[0148] Denatured, low-dose trypsin-treated HSA (8 .mu.g) in 25 mM
NH.sub.4HCO.sub.3, pH 8, was incubated with 8 .mu.g of the
monoclonal antibody (mAb A) or with a PBS control for 2 hours at
4.degree. C. A separate control consisting of 8 .mu.g monoclonal
antibody in 25 mM NH.sub.4HCO.sub.3 alone was also incubated in
parallel. The samples were vortexed briefly every 10 min. The
samples were then immediately dried over night in a SpeedVac vacuum
concentrator (Savant, Farmingdale, N.Y.). The samples were then
dissolved in 16 .mu.l of sequencing grade, modified trypsin at 5
.mu.g/ml (Promega) and incubated at 37.degree. C. for 18 hours. The
samples were stored at 4.degree. C. over night and then analysed by
MALDI TOF MS (see below).
[0149] Incubation of dHSA with mab Followed by Enzymatic Cleavage
with Trypsin with Ultrafiltration Under Acidic Conditions for
Epitope Mapping
[0150] Denatured HSA (80 .mu.g) was incubated with mAb A (10 .mu.g)
in PBS for 18 h at room temperature. To remove free dHSA. the
dHSA-mAb A reaction mixture was centrifuged for 5 min at 3000 rpm
in an Amicon Ultra-15 ultrafilter with a molecular weight cut-off
at 100 000 Da (Millipore Co., Billerica, Mass.). The retentate was
diluted in 25 mM NH.sub.4HCO.sub.3 and again centrifuged as
described above. The retentate was transferred to a sterile
eppendorf microcentrifuge tube in 0.4 ml 25 mM NH.sub.4HCO.sub.3
and 0.4 .mu.g sequencing grade modified trypsin (Promega) was
added. Digestion was carried out at 37.degree. C. over night with
gentle agitation. Trypsin and free (not antibody-bound) albumin
fragments were removed by ultrafiltration on a Amicon Ultra-4
filter (mw cut-off 30 000 Da, Millipore Co.) for 5 min at 3000 rpm.
This was repeated three times. The retentate was then transferred
to a new ultra filter where the mAb A was disassociated from bound
albumin by the addition of 600 .mu.l 0.1 M glycine-HCl, pH 2.7, for
30 min at room temperature after which the ultra filter was
centrifuged for 10 min at 3000 rpm. The filtrate was transferred to
a sterile Eppendorf microcentrifuge tube and neutralized with
Tris-HCl, pH 9. The sample was then immediately dried over night in
a SpeedVac vacuum concentrator. The samples were then dissolved in
16 .mu.l of sequencing grade modified trypsin (at 5 .mu.g/ml)
(Promega) and incubated at 37.degree. C. for 18 hours. Zip Tip
pipette tips (Millipore) containing C.sub.18 chromatography media
were used for desalting before the sample was analysed by MALDI TOF
ms (see below).
[0151] MALDI TOF Mass Spectrometry
[0152] 1 .mu.l of each sample of the tryptic digestion was mixed
with 1 .mu.l of a saturated solution of
.alpha.-cyano-4-hydroxycinamic acid (0.02 mg/ml) in 70%
acetonitrile/0.3% trifluoro acetic acid. 1 .mu.l of that mixture
was spotted on a stainless steel target plate and analysed using
MALDI-TOF ms (Voyager-DE PRO, Applied Biosystems, CA, US) equipped
with a 337 nm N.sub.2 laser. Database searches for masses
corresponding to human serum albumin in the resulting spectra were
performed in NCBI or SwissProt with MS-Fit as search engine.
[0153] Albumin Peptides
[0154] All synthetic albumin peptides used herein were custom
prepared by CSBio Co, Menlo Park, Calif. Peptides were >95% pure
as confirmed by HPLC. Peptides were kept freeze dried at minus
20.degree. C. Peptides were reconstituted in sterile H.sub.2O
(Sigma) for use in ELISA or in RPMI1640 (GIBCO) for use in cell
culture experiments. Peptides were sterile filtered through a 0.22
.mu.m syringe filter (Millipore Co) before use in cell culture
experiments.
[0155] Anti-dHSA ELISA, co-incubation of anti-dHSA mAb A with
synthetic albumin peptides Duplicate wells in Hi-binding microtitre
plates (Costar 2592, Corning Inc, NY, USA) were coated with 100
.mu.l of dHSA diluted in PBS at 4.5 .mu.g/ml and incubated at room
temperature overnight. The wells where then washed with wash buffer
consisting of 0.05% Tween-20 in PBS (Sigma) followed by blocking
for 1 hr at 25.degree. C. with 200 .mu.l 0.5% gelatin prepared from
bovine skin (Sigma) in PBS followed by washing in wash buffer. The
monoclonal antibody mAb A, diluted in ELISA reagent diluent (0.01%
gelatin and 0.05% Tween-20 in 20 mM Tris buffered saline (TBS,
Sigma)) at 4 ug/ml was pre-incubated for 1 hr at room temperature
with the indicated concentrations of the peptides. 100 .mu.l of the
monoclonal antibody alone, or, alternatively, the monoclonal
antibody mixed with peptides, was then added per well and incubated
for 1.5 hr at 25.degree. C. followed by washing. Envision-HRP
(DakoCytomation Norden A/S. Glostrup, Denmark) diluted 1/10 in
ELISA reagent diluent was added and the plates incubated for 15 min
at 25.degree. C. followed by washing. Finally, substrate solution
consisting of H.sub.2O.sub.2 and tetramethylbenzidine (R&D
Systems Europe, Ltd, Abingdon, UK) was added. The reaction was
stopped with 1M H.sub.2SO.sub.4 and the optical density measured as
absorbance (A) at dual wavelengths, 450 nm and 570 nm, with a
Multiscan EX microplate reader (Labsystems).
[0156] Correlation of Immunohistological Staining of Biopsies with
an Anti-dHSA mab (mAb A) and Survival in Patients with Malignant
Melanoma
[0157] Biopsies from tumours obtained from twenty patients
diagnosed with metastatic malignant melanoma were immediately snap
frozen in liquid nitrogen and stored at -70.degree. C. until use.
Frozen tissue sections, 6-7 .mu.m thick, were cut, thawed and fixed
with acetone for 5 min at room temperature. The sections were first
blocked with 10% normal human AB-serum for 1 h before staining.
Primary antibody, consisting of monoclonal mouse anti-human
denatured albumin (mAb-A) diluted in Tris buffered saline (TBS, pH
7.6) at 10 .mu.g/ml, was then added and the slides incubated for 30
min. The slides were washed in TBS followed by Envision-Alkaline
Phosphatase (DakoCytomation) for 30 min. After additional washing
in TBS, the slides were incubated in alkaline phoshatase substrate
consisting of Fast Red TR salt (Sigma), naphtol AS-MX (Sigma) and 5
mM levamisol (Sigma) to block endogenous alkaline phosphatase
activity, for 20 min followed by washing in TBS. They were then
counterstained in Mayer's haematoxylin for 1 minute and mounted in
Glycergel (Dakopatts). Monoclonal mouse IgG1 against an irrelevant
antigen (Aspergillus niger glukosoxidase, DakoCytomation) was used
as a negative control. All incubations were performed at room
temperature in a moist chamber. Intensity of staining was evaluated
in a light microscope and was ranked as low, medium or high.
Survival between groups was analysed according to Kaplan Meyer and
a log rank analyses.
[0158] Isolation of Peripheral Blood Mononuclear Cells (PBMC)
[0159] Venous blood was drawn from healthy volunteers or from
cancer patients in glass vacuum tubes with acid dextrose citrate
solution A as anti-coagulant (Vacutainer, Becton Dickinson,
Franklin Lakes, N.J.). Erythrocytes were removed by sedimentation
on 2% dextran T500 solution (Amersham Pharmacia Biotech AB,
Uppsala, Sweden) in 0.9% NaCl (this step was omitted for cultures
with PHA-stimulation-see below). PBMC were then isolated by
Ficoll-paque Plus (GE Healthcare Bio-Sciences AB, Uppsala, Sweden)
density gradient centrifugation after which the cells were washed
twice in RPMI 1640 Dutch's modification (Gibco, InVitrogen AB,
Stockholm, Sweden) with 2% human serum albumin (HSA) (Pharmacia
& Upjohn, Stockholm, Sweden) (RPMI/2% HSA). For cell cultures
with PHA-stimulation, PBMC were washed in Hank's Balanced Salt
Solution (HBSS) with 10% autologous plasma instead of RPMI/2% HSA.
Cell viability was assessed by exclusion of 0.05% Trypan Blue and
was always above 95%. The cell suspension was stained with Turk's
solution and the number of lymphocytes and monocytes in the PBMC
preparation were counted in a hemocytometer. PBMCs were suspended
in RPMI/2% HSA and the cell concentration adjusted to
5.times.10.sup.5 lymphocytes/ml.
[0160] Serum
[0161] Human serum was collected i serum collection tubes without
additives (Vacutainer, Becton Dickinson, Franklin Lakes, N.J.) at
the same time as blood samples for isolation of PBMC. The sera were
heat-inactivated at 56.degree. C. for 30 minutes.
[0162] PHA-Induced Proliferation of PBMC in the Presence of Albumin
Peptides and/or dHSA
[0163] PBMC from healthy volunteers, were resuspended in RPMI1640
with or without the addition of dHSA and/or albumin peptides, as
indicated, at a cell concentration of 5.times.10.sup.5
lymphocytes/ml. 100 d of the cell suspension were seeded into
round-bottomed microtiter plates (Corning, NY, USA) followed by 100
.mu.l of culture medium consisting of RPMI 1640 (Flow Laboratories,
Irvine, Scotland) supplemented with 200 IU/ml Penicillin, 200
.mu.g/ml Streptomycin (Flow laboratories) and 20% heat inactivated
autologous serum. Phytohemagglutinin (PHA-P, Sigma Chemical Co, St.
Louis, Mo.) at a final concentration of 5 or 10 .mu.g/ml was then
added. All culture conditions were set up in triplicate wells.
Cells were cultured for 3 days in a humidified 5% CO.sub.2
atmosphere at 37.degree. C. Proliferation was assayed by
incorporating of 1.6 .mu.Ci/well of [.sup.3H]thymidine (Amersham
International, U K) during the last 18 hr. Mean values of
disintegrations per minute (dpm) of triplicates were used for the
calculations.
[0164] LPS-Induced IL-6 Production, Effect of Peptides
[0165] 100 .mu.l of culture medium consisting of RPMI1640
supplemented with 200 IU/ml penicillin, 200 .mu.g/ml streptomycin,
4 mM L-glutamine (Sigma Chemical, MO. US) and 20% fresh
heat-inactivated autologous serum were added to un-coated or
-pre-coated microtiter plates followed by 100 .mu.l of PBMC
suspension (5.times.10.sup.4 lymphocytes) in RPMI/2% HSA with
peptides at the indicated concentrations. Lipoplysaccharide (LPS,
Sigma Chemical Co, MO, US) was added at a final concentration of
0.05 ng/ml. Cells were cultured in a humidified, 5% CO.sub.2
atmosphere at 37.degree. C. All assay conditions were set up in
triplicate wells. Supernatants (SNs) were harvested after 24 hrs
and residual cells were removed by centrifugation in a refrigerated
centrifuge (Beckman) at 2600.times.g for 5 minutes. SNs were frozen
and stored at -70.degree. C. IL-6 in cell culture SNs was measured
by ELISA using the DuoSet.RTM. ELISA development kit for human IL-6
(R&D Systems Europe, Ltd., Abingdon, UK) following the
manufacturer's recommended procedures. The lower limit of detection
was 3.1 .mu.g/ml. Samples were analysed as mean of triplicate
wells.
[0166] Interleukin-2 (IL-2) Induced Proliferation of PBMC in the
Presence of Albumin Peptides in Coated and Uncoated Tissue Culture
Plates
[0167] Round-bottomed, 96-well tissue culture plates (Costar,
Corning Inc. NY, US) were pre-coated with HSA only or HSA and
pooled human IgG for intravenous injection (Gammagard, Baxter AS,
DK) as follows; HSA was diluted in RPMI1640 without supplements to
a concentration of 10 mg/ml. A mixture of 1 mg/ml IgG in a solution
of 9 mg/ml HSA in RPMI (HSA/IgG) was also prepared. 200 .mu.l of
HSA or HSA/IgG were then added to each well of the plate. The
plates were incubated at 4.degree. C. for 30 minutes after which
the wells were washed twice with 200 .mu.l of RPMI1640. The coated
plates were used immediately. 100 .mu.l of RPMI1640 supplemented
with 200 IU/ml penicillin, 200 .mu.l/ml streptomycin, 4 mM
L-glutamine (all from Sigma Chemical Co. MO, US) and 20%
heat-inactivated human serum (autologous) were added to the HSA or
HSA/IgG coated tissue culture microtiter wells. PBMC, isolated from
healthy individuals, were diluted in RPMI/2% HSA and peptides were
added directly to the cell suspension at a concentration of 10
.mu.g/ml. One hundred .mu.l of this cell suspension
(5.times.10.sup.4 lymphocytes) was then added per well providing a
final concentration of 5 .mu.g/ml peptide per well. IL-2
(Proleukin, Chiron, NL), at a final concentration of 120 IU/well,
was added to the wells. Cells were cultured for 7 days in a
humidified, 5% CO.sub.2-atmosphere at 37.degree. C. Proliferation
was assayed by incorporation of 1.6 .mu.Ci/well of [3H]-thymidine
(Amersham Int., UK) during the last 18 hrs. Mean values of dpm
(disintegrations per minute) of triplicates were used for the
calculations.
[0168] Immunocytochemical Staining of PBMC and a Human, Monocytic
Cell Line with an Anti-Integrin (CD11a) Antibody in the Presence or
Absence of Albumin Peptides
[0169] PBMC were separated as described above. Cultured THP-1 cells
(obtained from the American Type Culture Collection through LGL
Nordic AB, Sweden) were carefully washed and suspended in RPMI1640.
PBMC and THP-1 were immediately spun down on pre-cleaned microscope
slides in a Shandon Cytospin (Shandon Scientific Ltd, UK) at 1000
RPM for 7 min at 2.5 or 5.times.10.sup.4 cells per slide. The
slides were left to dry at room temperature over night, after which
they were wrapped in parafilm and stored at -70.degree. C.
Immediately before use, the cytospins were thawed and fixed with
acetone for 5 min at room temperature. The cytospins were first
blocked with 10% normal human AB-serum with and without albumin
peptides (40 .quadrature.g/ml) for 1 h before staining. Primary
antibody, consisting of a monoclonal mouse anti-human CD11a (clone
HI111, BD Biosciences) diluted in Tris buffered saline (TBS, pH
7.6) at 5 .mu.g/ml (THP-1) or 1 .quadrature.g/ml (PBMC), was added.
The slides were incubated for 30 min and then washed in TBS
followed by Envision-Alkaline Phosphatase (Dako Norden A/S,
Denmark) for 30 min. After additional washing in TBS, the slides
were incubated in alkaline phoshatase substrate consisting of Fast
Red TR salt (Sigma), naphtol AS-MX (Sigma) and 5 mM levamisol
(Sigma) to block endogenous alkaline phosphatase activity, for 20
min followed by washing in TBS. They were then counterstained in
Mayer's haematoxylin for 1 minute and mounted in Glycergel (Dako
Norden A/S). Monoclonal mouse IgG1 against an irrelevant antigen
(Aspergillus niger glukosoxidase, Dako Norden A/S) was used as a
negative control. All incubations were performed at room
temperature in a moist chamber.
[0170] Proteolytic Fragmentation of Denatured Human Serum Albumin
(dHSA) with Trypsin or Endoproteinase ASP-N
[0171] Freeze dried dHSA (0.5 mg) was reconstituted in 25 mM
NH.sub.4HCO.sub.3, pH 8, containing 10 mg sequencing grade modified
trypsin (Promega Corporation, WI) or 2 mg Endoproteinase ASP-N
(Sigma) and incubated at 37.degree. C. over night. To remove
unfragmented albumin and enzyme, the sample was ultra filtered
through an Amicon Ultra 4 (mw cut-off of 5000) or a Centriplus (mw
cut-off 10000) centrifugal filter (Millipore AB, Solna, Sweden).
The filtrate, containing fragmented dHSA without enzymes, was
collected and diluted with PBS with Ca and Mg (GIBCO).
[0172] Preparation of Cell Lysate from PBMC with Biotinylated Cell
Surface Proteins (ACS)
[0173] Buffy coats generated from 450 ml blood each was collected
from 4 healthy donors. Erythrocytes were removed by sedimentation
on 2% dextran T500 solution (Amersham Pharmacia Biotech AB, Uppsala
Sweden) in 0.9% NaCl. Mononuclear cells (PBMC) were then isolated
by Ficoll-Paque Plus (GE Healthcare Bioscience AB Sweden) density
gradient centrifugation. The PBMC were then suspended in phosphate
buffered saline (PBS) containing Ca and Mg (GIBCO) at a
concentration of 10.times.10.sup.6/ml. EZ Link Sulfo-NHS-biotin
(Pierce USA) was added at a final concentration of 0.2 mg/ml and
the mixture incubated on a shaker at room temperature for 10 min.
Excess biotin was then removed by washing the PBMC in PBS.
Biotinylated PBMC were then lysed by adding 1.0 ml ice-cold lysing
buffer (50 mM Tris-HCL, pH 7.5, with 0.15 M NaCl, 5 mM MgCl.sub.2
containing 100 mM Octyl glucoside and 1 mM Phenylmethylsulfonyl
fluoride) per 2.times.10.sup.7 pelleted cells with gentle shaking,
then incubated for 30 min. on ice. Debris was removed by
centrifugation at 5000.times.g at 4.degree. C. for 10 min and the
supernatants was collected and pooled from all four donors. The
lysate was then stored at -70.degree. C. in polypropylene plastic
tubes.
[0174] Preparation of affinity column with biotinylated cell
surface proteins from mononuclear cells coupled to
streptavidin-sepharose (used for adsorption of trypsin fragmented
dHSA) 18 ml biotinylated cell lysate in lysate buffer was diluted
1/10 in binding buffer (20 mM NaH.sub.2PO.sub.4, 0.15 M NaCl, pH
7.5). This amount of lysate corresponds to 36.times.10.sup.7
mononuclear cells. It was added to a 1 ml Hitrap Streptavedin HP
affinity column (Amersham Biosciences).
[0175] To block possible remaining free biotin, 5 ml of 0.1 M
glycine (Sigma) was added to the column. Unsaturated streptavedin
on the column was then reacted with 150 ug biotin (Sigma) in
binding buffer. The column was carefully washed with PBS and stored
in PBS with 0.1% NaN.sub.3 at 4.degree. C. until use.
[0176] Preparation of affinity column with biotinylated cell
surface proteins from mononuclear cells coupled to
streptavidin-sepharose (used for adsorption of ASP-N fragmented
dHSA) Biotinylated cell lysate in lysate buffer underwent buffer
exchange by dialysis with Spectrapore 4 dialysis tubing (Spectrum
Europe, Breda, The Netherlands) in binding buffer (20 mM
NaH.sub.2PO.sub.4, 0.15 M NaCl pH 7.5). 27 ml biotinylated cell
lysate in binding buffer (corresponding to 54.times.10.sup.7
mononuclear cells) was added to 1.5 ml washed Streptavidin
Sepharose HP (Amersham Biosciences). To block possible remaining
free biotin, 25 ml of 0.1 M glycine (Sigma) was added to the
Streptavidin Sepharose. Unsaturated streptavedin was then reacted
with 225 .mu.g biotin (Sigma) in binding buffer. The Streptaivin
Sepharose was carefully washed in PBS. One ml of the biotinylated
cell lysate coupled Streptavidin Sepharose was then packed in an
empty column (Tricorn Empty High Performance Column, Amersham
Bioscience) and washed with phosphate buffered saline (PBS)
containing Ca and Mg (GIBCO).
[0177] Adsorption of Enzyme Fragmented dHSA Using an Affinity
Column with Biotinylated Cell Surface Proteins (ACS)
[0178] Two ml of enzyme-fragmented dHSA in PBS, corresponding to a
total of 0.2 mg protein, was passaged over the ACS column, prepared
as described above. The flow-through was collected with
consideration taken to void volume and dilution of adsorbed sample
by collecting in small portions of 0.2 ml. Thirty ul of each
sample, including a control sample that has not been adsorbed, were
dried in a Speed-Vac centrifuge.
[0179] Mass Spectrometry
[0180] Dried samples were reconstituted in 10 ul of 0.1% TFA. Zip
Tip pipette tips (Millipore, USA) containing C.sub.18
reversed-phase media were used for desalting reconstituted samples.
For analysis of samples in the mass range 700-3600 Da, one .mu.l of
each Zip Tip eluted sample was mixed with 1 .mu.l of a saturated
solution of .alpha.-cyano-4-hydroxycinamic acid (0.02 mg/ml) in 70%
acetonitrile/0.3% trifluoro acetic acid. For the analysis of
samples in the mass range 1500-9000 Da, one .mu.l of each Zip Tip
eluted sample was mixed with 1 .mu.l of sinapinic acid
(3-methoxy-4-hydroxycinnamic acid). 1 .mu.l of the mixture was
spotted on the MALDI plate and analysed using MALDI-TOF MS
(Voyager-DE PRO, Applied Biosystems, CA, US). Mass identity search
of resulting spectra was performed in the SwissProt or NCBI
databases using MS-Fit.
[0181] Identification of Proteins in Human Plasma Binding to
ACS
[0182] Affinity chromatography of plasma with ACS
[0183] Plasma was obtained by plasmapheresis from a patient
diagnosed with malignant melanoma. The plasma was frozen at
-20.degree. C. Upon thawing the plasma was immediately clotted by
the addition of CaCl.sub.2 to a final concentration of 13 mM. The
gelled plasma clot was removed by centrifugation at 3500 RPM for 7
min at 4.degree. C. The plasma was then dialysed extensively
against PBS using Spectrapore 4 dialysis tubing (Spectrum Europe,
Breda, The Netherlands). An affinity column with biotinylated cell
surface proteins from mononuclear cells coupled to
streptavidin-sepharose (ACS-sepharose) was prepared as described
above. 45 ml of the plasma was incubated with the ACS-sepharose
over night at 4.degree. C. with gentle agitation. The plasma-ACS
sepharose was extensively washed with PBS. The washed ACS-sepharose
was stored for five days at 4.degree. C. in PBS with 0.1%
NaN.sub.3. The ACS-sepharose was packed in an empty column (Tricom
Empty High Performance Column, Amersham Bioscience) and bound
proteins were eluted with 2 ml of 0.1 M Glycine-HCl, pH 2.7. The
eluted fraction was immediately neutralized with 1 M Tris buffer at
pH 9 and freeze dried.
[0184] 2-D Gel Electrophoresis
[0185] Freeze dried samples were desalted by reconstituting in
H.sub.2O and 10% trichloro acetic acid (TCA) with 20 mM DTT in
acetone. The samples were centrifuged at 13000 RPM for 5 min. The
resulting pellet was washed twice with 20 mM DTT in acetone to
remove TCA and finally dissolved in a rehydration buffer (8 M urea,
4% CHAPS, 10 mM DTT, 0.5% IPG buffer and a trace of orange G).
Two-dimensional gel electrophoresis was performed in a horizontal
2-DE set-up (Multiphore/IPGphore, Pharmacia Biotech, SE) based on
isoelectric focusing (IEF) in the first dimension and molecular
mass in the second dimension. Briefly, samples were applied to IPG
gels (Immobiline.TM. Dry strip, pH 3-10 NL, (GE Healthcare)) and
focused overnight at 38060 Vh. SDS-PAGE was then carried out with
Exelgel XL SDS 12-14 polyacrylamide precasted slab gels (Amersham
Biosciences). Molecular weight standards were included in each run.
Separated proteins were detected by silver stain according to the
method of Shevenco. Tryptic digests of proteins spots were excised
from the gel and analysed with MALDI-TOF ms as described above.
[0186] Cancer Patients
[0187] Patients, included in the analyses of over-all survival
according to proliferative response of peripheral blood mononuclear
cells (PBMC) to interleukin-2, were diagnosed with systemic
metastatic renal cell carcinoma. They were previously untreated and
scheduled for Interelukin-2 treatment (Proleukin, Chiron, NL).
Blood samples were taken prior to initiation of treatment. Patients
included in other studies in this patent application are briefly
described as appropriate in the result section.
[0188] Ex Vivo Model of IL-2 Related Immunosuppression;
Interleukin-2 (IL-2) Induced Proliferation of PBMC
[0189] PBMC were isolated from venous blood samples from healthy
blood donors (controls) or cancer patients. One hundred .mu.l of
culture medium (RPMI 1640 Dutch's modification (Gibco, InVitrogen
AB, Stockholm, Sweden) supplemented with 200 IU/ml penicillin, 200
.mu.l/ml streptomycin, 4 mM L-glutamine (all from Sigma Chemical
Co. MO, US) and 20% heat-inactivated human serum) were added to
round-bottomed, 96-well tissue culture plates (Costar, Corning Inc.
NY, US). One hundred .mu.l of PBMCs in RPMI/2% HSA
(5.times.10.sup.4 lymphocytes) was then added per well followed by
IL-2 (Proleukin, Chiron, NL) at a final concentration of 120
IU/well. Control wells without IL-2 was set up in parallel. Cells
were cultured for 7 days in a humidified, 5% CO.sub.2-atmosphere at
37.degree. C. Cell proliferation was assayed by incorporation of
1.6 .mu.Ci/well of [3H]-thymidine (Amersham Int., UK) during the
last 18-24 h hrs. Mean values of dpm (disintegrations per minute)
of triplicate wells were used for the calculations. In cultures
were serum collected from cancer patients were used instead of
autologous serum, PBMCs were from blood type compatible donors.
[0190] Interleukin-2 (IL-2) induced proliferation of PBMC in the
presence of albumin peptides Cultures for IL-2 induced
proliferation was set up with PBMC from healthy donors and
autologous serum as described above with the exception that PBMC
were first pre-incubated for 30 min at room temperature with the
indicated albumin peptides at a concentration of 10 g/ml.
[0191] Generation of Rabbit Antiserum Specific for Albumin Peptide
3028
[0192] Peptide 3028 was synthesized with a cysteine added to the
N-terminus end and then conjugated with keyhole limpet hemocyanin
(KLH) as a carrier protein. Polyclonal antisera were generated by
repeated immunizations of rabbits with KLH-conjugated peptide 3028
and Freund's adjuvants. For some experiments, the antisera were
affinity purified by chromatography on peptide 3028-conjugated
Ultralink lodoacetyl gels (Pierce Biotechnology Inc.). For cell
culture experiments, buffer exchange to RPMI 1640 Dutch's
modification (Gibco, InVitrogen AB, Stockholm, Sweden) was
performed by passage over PD-10 sephadex columns (Amersham
Biosciences, Uppsala, Sweden) followed by filter sterilization on
0.22 .mu.m Millex syringe filters (Millipore Co., MA, USA). Rabbit
immunizations and purification of antisera were carried out by
Agrisera AB, Sweden.
[0193] ELISA with Rabbit-Anti 3028 Antiserum
[0194] Duplicate wells in Hi-binding microtitre plates (Costar
2592, Corning Inc, NY, USA) were coated with 100 .mu.l of peptide
3028 (10 ug/ml), denatured HSA (denHSA. 4.5 ug/ml) or control HSA
(4.5 ug/ml). All coating reagent were diluted in PBS and incubated
at room temperature overnight. The wells where then washed with
wash buffer consisting of 0.05% Tween-20 in PBS (Sigma) followed by
blocking for 1 hr at 25.degree. C. with 200 .mu.l 0.5% gelatin
prepared from bovine skin (Sigma) in PBS followed by washing in
wash buffer. Rabbit preimmune sera or anti-3028 sera, diluted
1/1000 000 in ELISA reagent diluent (0.01% gelatin and 0.05%
Tween-20 in PBS), were added and incubated for 1 h at 25.degree. C.
followed by washing. Biotinylated horse anti-rabbit/mouse IgG
(Vectastain ELITE, Vetor Laboratories Inc, CA, USA) diluted 1/5 in
ELISA reagent diluent was then added and the plates incubated for 1
h at 25.degree. C. followed by washing. Next, HRP-conjugated
strreptavidine (R&D systems Europe, Ltd, UK) was added.
Finally, after washing in wash buffer, substrate solution
consisting of H.sub.2O.sub.2 and tetramethylbenzidine (R&D
Systems) was added. The reaction was stopped with 1M
H.sub.2SO.sub.2 and the optical density measured as absorbance (A)
at dual wavelengths, 450 nm and 570 nm, with a Multiscan EX
microplate reader (Labsystems).
[0195] Inhibition of Rabbit Anti-3028 ELISA by Albumin Peptides
[0196] To test if albumin peptides inhibited the binding of the
rabbit anti-3028 to 3028 coated wells, rabbit antisera, diluted
1/1000 000 in ELISA reagent diluent, was pre-incubated for 1 hr at
room temperature with the indicated concentrations of the peptides.
100 .mu.l of the monoclonal antibody alone, or, alternatively, the
monoclonal antibody mixed with peptides, was then added to 3028
coated wells and the ELISA carried out as described.
[0197] Interleukin-2 (IL-2) Induced Proliferation of PBMC in the
Presence of Affinity Purified Rabbit Anti-3028
[0198] Cultures to test the immunomodulary effect of affinity
purified rabbit antibodies specific for 3028 was performed as
described above for IL-2 induced proliferation with the following
exceptions; 2% HSA was omitted from the washing medium and from the
PBMC suspension medium. Serum containing culture medium (100
ul/well) was pre-incubated with 20 ug/ml of rabbit antibodies for
30 min at room temperature before the addition of 100 ul PBMC
suspension to the culture wells.
[0199] Immunohistochemical Staining of Tumor Biopsies with Rabbit
Anti-3028
[0200] Tissue sections were prepared from formalin fixed biopsies
from cancer patients. Sections were de-paraffinased and blocked
with 10% normal, human AB-serum in Hank's balanced salt solution
supplemented with 0.01 M Hepes (BSS, GIBCO BRL) for one h prior to
staining. Sections were then stained with 10 ug/ml affinity
purified rabbit anti-3028 diluted in BSS with 2% AB-serum and 0.1
g/ml saponin for 30 min. After washing in BSS with 0.1 g/ml
saponin, Ultravison One alkaline phosphatatase polymer specific for
mouse and rabbit Ig (Lab Vision Co., CA, USA) was added. Excess
polymer was then washed from the sections with BSS with 0.1 g/ml
saponin. Bound polymer complex was the detected by naphthol
phosphate substrate and liquid Fast Red chromogen (Lab Vision
Corp.) The sections were counter stained in Mayer's haematoxylin
and mounted in Glycergel.
[0201] Effect of Albumin Peptides on Cytotoxic Activity of Natural
Killer (NK) Cells from Healthy Blood Donors
[0202] Mononuclear cells were separated by standard Ficoll-paque
Plus (Pharmacia AB, Sweden) density gradient centrifugation from
heparinized blood obtained from healthy donors. NK cell cytotoxic
activity of the mononuclear cells was then tested using a
commercial kit (NKTEST, Orpegen Pharma GmbH, Heidelberg, Germany)
following the manufacturers protocol. Briefly, the kit contains
cryopreserved, NK-sensitive target cells (K562) labelled with a
lipophilic green fluorescent membrane dye, which enables
discrimination of effector and target cells. After incubation with
effector cells, killed target cells are identified by a DNA-stain,
which penetrates and specifically stain the nuclei of dead target
cells. This way the percentage of killed targets can be determined
by flow cytometry. The mononuclear cells were pre-incubated for 30
min at 37.degree. C. with the indicated peptides (peptides have
been described previously) at 10 ug/ml. Target cells were then
added, giving an effector:target ratio of 40:1, and the cell
mixture incubated at 37.degree. C. for 3-4 hours. Samples were
analysed on a FACSCalibur (BD Biosciences, San Jose, Calif.).
BRIEF DESCRIPTION OF THE DRAWINGS
[0203] FIG. 1. This diagram shows that some peptides containing the
E5K sequence inhibit the binding of mAb A to ELISA plates coated
with dHSA. Obviously there is some differences in the inhibitory
activity of the tested peptides.
[0204] FIG. 2. Effect of expression of E5K detected by mAb A on
survival of patients with metastatic malignant melanoma
(p=0.009).
TABLE-US-00013 Low expression x - - x High expression .smallcircle.
- - .smallcircle.
[0205] FIG. 3 A. Effect of two albumin peptides, 2605 and 2608, on
PHA (5 .mu.g/ml) induced proliferation of PBMCs from one healthy
control and two cancer patients was tested. The three different
concentrations of the peptides (.mu.g/ml) are indicated in the
figure. Patients P45 and 46 suffered from renal cell carcinoma and
malignant melanoma.
[0206] FIG. 3 B. Effect of two albumin peptides, 2605 and 2608, on
PHA (10 .mu.g/ml) induced proliferation of PBMCs from one healthy
control and two cancer patients was tested. The three peptide
concentrations (.mu.g/ml) used are indicated in the figure.
[0207] FIG. 4. Inter-individual variation in the effect of albumin
peptides on PHA induced proliferation by PBMCs from healthy
controls and cancer patients. PHA was used at a concentration of 5
.mu.g/ml and the peptides at a concentration of 10 .mu.g/ml. The
patients had the following diagnoses: Malignant melanoma (P46) and
renal cell carcinoma (P39, P 41 and P45).
[0208] FIG. 5. Effect of dHSA, 8 .mu.g/ml, on PHA induced
proliferation of PBMCs from 5 controls and 4 cancer patients.
[0209] FIG. 6 A. Effect of peptide 2605 on dHSA enhanced PHA
induced proliferation. The details are described in the text.
[0210] FIG. 6 B. Effect of peptide 2608 on dHSA enhanced PHA
induced proliferation. The details are described in the text.
[0211] FIGS. 7A-C. Effect of albumin peptides on LPS-induced IL-6
production by PBMC from FIG. 7A a healthy donor, FIGS. 7B and 7C
cancer patients with malignant melanoma. PBMC were stimulated with
LPS for 24 h in the presence of the indicated peptides at 0.01
.mu.g/ml (black bars), 0.1 .mu.g/ml (grey bars), 1 .mu.g/ml (white
bars) or 10 .mu.g/ml (hatched bars). The amount of IL-6 released
into the culture medium was measured by ELISA. Results are
expressed as percent of IL-6 released in control cultures without
the addition of peptides. This was 1072 .mu.g/ml, 997 .mu.g/ml and
902 .mu.g/ml in FIGS. 7A, 7B, and 7C, respectively.
[0212] FIGS. 8 A-F. Effect of albumin peptides on the binding of
antibodies to LFA-1 on immune cells. The monocytic cell line THP-1
(FIGS. 8A and 8B), PBMC from two healthy controls (FIGS. 8C, 8D,
and 8E, 8F, respectively). Peptide 2606 was used in experiments
shown in FIG. 8B and FIG. 8D and peptide 2605 was used in FIG.
8F.
[0213] FIGS. 9A-D. Effect of peptides on dHSA modulated PHA induced
proliferation of PBMCs
[0214] FIGS. 10A-B. Effect of the new series of peptides on IL-2
induced proliferation (FIG. 10A) and reversal of the inhibitory
activity of peptide 3028 by Fc-receptor modulation (FIG. 10B).
[0215] FIGS. 11A-D. Effect of the new series of peptides on LPS
induced IL-6 production by PBMCs from two healthy controls.
[0216] FIGS. 12A-D. Effect of the new series of peptides on LPS
induced IL-6 production by PBMCs from three cancer patients, with
malignant melanoma (MM) and with renal cell carcinoma (RCC).
[0217] FIG. 13. 2-D gel electrophoresis of proteins from plasma
after ACS affinity chromatography. The plasma was obtained from a
patient with malignant melanoma.
[0218] FIG. 14. IL-2 induced proliferation by PBMC from healthy
controls and PBMC from renal cell carcioma patients (RCC) cultured
in 10% autologous sera.
[0219] FIG. 15. A Kaplan Meyer analysis of renal cell carcinoma
patients according to proliferative response to IL-2. A low
proliferative rate indicates a poor survival.
[0220] FIG. 16. Culture of PBMCs from healthy controls in sera from
cancer patients known to have a suppressed response to IL-2 in the
ex vivo model.
[0221] FIG. 17. Analysis of the effect of four different peptides
on IL-2 induced proliferation of PBMCs from healthy controls. PBMCs
were culture for 7 days in the presence of IL-2 (20 U/ml) and the
peptides. Proliferation was measured as incorporation of
.sup.3H-thymidine during the final 18 hours.//Control PBMC, (None
vs 3028, *p<0.0006, n=17) (Note, 3026, 3027, 3029 n=4 or 5).
[0222] FIG. 18. Inhibition of the proliferative response to IL-2 by
peptide 3028 in the human ex vivo model using cancer patient
PBMCs.
[0223] FIG. 19A. Effect of the C- (3218) and N-terminal (3325)
parts of peptide 3028 on 11-2 induced proliferation in comparison
with the effect of the whole/full length peptide 3028. One
representative experiment is shown. FIG. 19B. The inhibitory effect
of peptide 3028 on IL-2 induced proliferation is not neutralised by
the C- (3218) and N-terminal (3325) parts of peptide 3028 alone or
in combination.
[0224] FIG. 20. Antisera, but not preimmune sera, from two rabbits
immunized with the albumin peptide 3028 bind to wells coated with
the 3028 peptide, denatured HSA (denHSA) and, to a lesser extent,
to control treated (not denatured) HSA, which has been prepared
just as the denatured HSA except for the denaturation
procedure.
[0225] FIG. 21. Inhibition of the binding of rabbit-anti 3028 serum
L to wells coated with the 3028 peptide in an ELISA by albumin
peptides. Peptide 2607, containing the E5K structure, is used as a
negative control.
[0226] FIG. 22A-B. Effect of affinity purified antibodies directed
against peptide 3028 on the proliferative response to IL-2 of PBMCs
from immunosuppressed cancer patients and normal controls with
down-regulation of immune reactivity. P21 has renal cell carcinoma
and p26, p28 and p29 have malignant melanoma.
[0227] FIG. 23. Immunohistochemical staining of a malignant
melanoma metastases using affinity purified rabbit antibodies
directed to the 3028 epitope.
[0228] FIG. 24A-D. Inhibition of the binding of anti-LFA-1, mab
HI111, to mononuclear blood cells by 3028 peptide and fragments
3325 and 3218. A standard immunohistochemical staining procedure
using acetone fixation, 10% human AB-serum for blocking, incubation
with HI 111 and a secondary antibody (Ultravision, an alkaline
phosphate conjugated polymer attached to Fab-fragments of goat
anti-mouse Ig), followed by development with Fast Red. The slides
were then mounted in Glycergel. Preincubation with peptides added
to the AB serum was as follows: FIG. 24A. No peptide added, FIG.
24B. peptide 3028, FIG. 24C. The C-terminal part (3218), and FIG.
24D. The N-terminal part (3325).
[0229] FIG. 25A-B. Demonstration using computer assisted molecular
modelling that peptide 3028 binds to CD25 at the IL-2 binding site
The .alpha.-chain of the IL-2 receptor (CD25) binding peptide 3028
(FIG. 25A) at the IL-2 binding site (FIG. 25B). CD25 yellow and
IL-2 blue.
[0230] FIG. 26. Difference in anti-proliferative activity of
peptides 3218 an 3325, specificity of the affinity purified
antibodies directed to peptide 3325 and not to peptide 3218,
immunomodulatory activity these antibodies, and the effect of these
peptides on the binding of the anti-LFA-1 mAb to immune cells) it
can be concluded that neither of the minor peptides, 3218 or 3325,
are as efficient as the complete peptide, 3028.
[0231] FIGS. 27A-D. Effect of albumin peptides on cytotoxic
activity of natural killer (NK) cells from healthy blood
donors.
[0232] FIGS. 28A-B. Table 4A. E3-7K sequences in HSA.
[0233] FIGS. 29A-B. Table 4B. K3-7E sequences in HSA.
REFERENS LISTING
[0234] 1. Suckau D et al, PNAS, 1990, 87:9848. [0235] 2. Macht M et
al, Biochhemistry, 1996, 35:15633. [0236] 3. Kiselar J G and
Downard K M, Anal Chem 1999, 71:1792. [0237] 4. Davis G E, Exp.
Cell Res, 1992, 200; 242. [0238] 5. Doyen N et al. Mol Immunol,
1985, 22:1-10 [0239] 6. Peterson N C. Advances in monoclonal
antibody technology: Genetic engineering of mice, cells and
immunoglobulins. ILAR Journal, 2005, 46:314-9.
Sequence CWU 1
1
19515PRTHOMO SAPIENS 1Glu Glu Asn Phe Lys1 525PRTHOMO SAPIENS 2Glu
Asp His Val Lys1 535PRTHOMO SAPIENS 3Glu Asn Cys Asp Lys1
545PRTHOMO SAPIENS 4Glu Thr Phe Leu Lys1 555PRTHOMO SAPIENS 5Glu
Arg Ala Phe Lys1 565PRTHOMO SAPIENS 6Glu Cys Cys Glu Lys1
575PRTHOMO SAPIENS 7Glu Cys Tyr Ala Lys1 585PRTHOMO SAPIENS 8Glu
Arg Gln Ile Lys1 595PRTHOMO SAPIENS 9Glu Lys Cys Cys Lys1
5105PRTHOMO SAPIENS 10Glu Glu Gly Lys Lys1 5116PRTHOMO SAPIENS
11Glu Glu Thr Phe Leu Lys1 5126PRTHOMO SAPIENS 12Glu Thr Phe Leu
Lys Lys1 5136PRTHOMO SAPIENS 13Glu Thr Thr Leu Glu Lys1 5146PRTHOMO
SAPIENS 14Glu Thr Tyr Val Pro Lys1 5156PRTHOMO SAPIENS 15Glu Arg
Gln Ile Lys Lys1 5166PRTHOMO SAPIENS 16Glu Leu Val Lys His Lys1
5177PRTHOMO SAPIENS 17Glu Val Ala His Arg Phe Lys1 5187PRTHOMO
SAPIENS 18Glu Val Thr Glu Phe Ala Lys1 5197PRTHOMO SAPIENS 19Glu
Cys Phe Leu Gln His Lys1 5207PRTHOMO SAPIENS 20Glu Glu Thr Phe Leu
Lys Lys1 5217PRTHOMO SAPIENS 21Glu Leu Leu Phe Phe Ala Lys1
5227PRTHOMO SAPIENS 22Glu Leu Arg Asp Glu Gly Lys1 5237PRTHOMO
SAPIENS 23Glu Phe Ala Gly Val Ser Lys1 5247PRTHOMO SAPIENS 24Glu
Lys Pro Leu Leu Glu Lys1 5257PRTHOMO SAPIENS 25Glu Ser Lys Asp Val
Cys Lys1 5267PRTHOMO SAPIENS 26Glu Pro Gln Asn Leu Ile Lys1
5277PRTHOMO SAPIENS 27Glu Gln Leu Gly Glu Tyr Lys1 5287PRTHOMO
SAPIENS 28Glu Lys Glu Arg Gln Ile Lys1 5298PRTHOMO SAPIENS 29Glu
Ser Ala Glu Asn Cys Asp Lys1 5308PRTHOMO SAPIENS 30Glu Met Ala Asp
Cys Cys Ala Lys1 5318PRTHOMO SAPIENS 31Glu Cys Cys Gln Ala Ala Asp
Lys1 5328PRTHOMO SAPIENS 32Glu Gly Lys Ala Ser Ser Ala Lys1
5338PRTHOMO SAPIENS 33Glu Glu Pro Gln Asn Leu Ile Lys1 5348PRTHOMO
SAPIENS 34Glu Val Ser Arg Asn Leu Gly Lys1 5358PRTHOMO SAPIENS
35Glu Lys Glu Arg Gln Ile Lys Lys1 5368PRTHOMO SAPIENS 36Glu Leu
Val Lys His Lys Pro Lys1 5379PRTHOMO SAPIENS 37Glu Asn Gln Asp Ser
Ile Ser Ser Lys1 5389PRTHOMO SAPIENS 38Glu Lys Cys Cys Lys Ala Asp
Asp Lys1 5399PRTHOMO SAPIENS 39Glu Thr Cys Phe Ala Glu Glu Gly Lys1
5405PRTHOMO SAPIENS 40Lys Asp Leu Gly Glu1 5415PRTHOMO SAPIENS
41Lys Leu Val Asn Glu1 5425PRTHOMO SAPIENS 42Lys Gln Glu Pro Glu1
5435PRTHOMO SAPIENS 43Lys Tyr Leu Tyr Glu1 5445PRTHOMO SAPIENS
44Lys Val His Thr Glu1 5455PRTHOMO SAPIENS 45Lys Tyr Ile Cys Glu1
5465PRTHOMO SAPIENS 46Lys Glu Cys Cys Glu1 5475PRTHOMO SAPIENS
47Lys Pro Leu Leu Glu1 5485PRTHOMO SAPIENS 48Lys Asn Tyr Ala Glu1
5495PRTHOMO SAPIENS 49Lys Val Phe Asp Glu1 5505PRTHOMO SAPIENS
50Lys Pro Leu Val Glu1 5515PRTHOMO SAPIENS 51Lys Gln Asn Cys Glu1
5525PRTHOMO SAPIENS 52Lys Cys Cys Thr Glu1 5535PRTHOMO SAPIENS
53Lys Ala Thr Lys Glu1 5546PRTHOMO SAPIENS 54Lys Asp Leu Gly Glu
Glu1 5556PRTHOMO SAPIENS 55Lys Lys Tyr Leu Tyr Glu1 5566PRTHOMO
SAPIENS 56Lys Ala Ala Phe Thr Glu1 5576PRTHOMO SAPIENS 57Lys Ala
Glu Phe Ala Glu1 5586PRTHOMO SAPIENS 58Lys Pro Leu Val Glu Glu1
5596PRTHOMO SAPIENS 59Lys Glu Phe Asn Ala Glu1 5606PRTHOMO SAPIENS
60Lys Ala Asp Asp Lys Glu1 5617PRTHOMO SAPIENS 61Lys Thr Cys Val
Ala Asp Glu1 5627PRTHOMO SAPIENS 62Lys Leu Lys Glu Cys Cys Glu1
5637PRTHOMO SAPIENS 63Lys Ser His Cys Ile Ala Glu1 5647PRTHOMO
SAPIENS 64Lys Cys Cys Lys His Pro Glu1 5657PRTHOMO SAPIENS 65Lys
Arg Met Pro Cys Ala Glu1 5667PRTHOMO SAPIENS 66Lys Gln Thr Ala Leu
Val Glu1 5677PRTHOMO SAPIENS 67Lys Pro Lys Ala Thr Lys Glu1
5687PRTHOMO SAPIENS 68Lys Glu Thr Cys Phe Ala Glu1 5698PRTHOMO
SAPIENS 69Lys Leu Val Asn Glu Val Thr Glu1 5708PRTHOMO SAPIENS
70Lys Gln Glu Pro Glu Arg Asn Glu1 5718PRTHOMO SAPIENS 71Lys Leu
Asp Glu Leu Arg Asp Glu1 5728PRTHOMO SAPIENS 72Lys Thr Tyr Glu Thr
Thr Leu Glu1 5738PRTHOMO SAPIENS 73Lys Gln Asn Cys Glu Leu Phe Glu1
5748PRTHOMO SAPIENS 74Lys Lys Gln Thr Ala Leu Val Glu1 5758PRTHOMO
SAPIENS 75Lys Glu Thr Cys Phe Ala Glu Glu1 5769PRTHOMO SAPIENS
76Lys Arg Tyr Lys Ala Ala Phe Thr Glu1 5779PRTHOMO SAPIENS 77Lys
Asp Val Cys Lys Asn Tyr Ala Glu1 5789PRTHOMO SAPIENS 78Lys His Lys
Pro Lys Ala Thr Lys Glu1 5799PRTHOMO SAPIENS 79Glu Lys Asp Asp Ala
Lys Cys Cys Lys1 58017PRTHOMO SAPIENS 80Val Phe Asp Glu Phe Lys Pro
Leu Val Glu Glu Pro Gln Asn Leu Ile1 5