U.S. patent number 7,741,297 [Application Number 10/502,085] was granted by the patent office on 2010-06-22 for immunostimulatory, covalently lipidated oligonucleotides.
This patent grant is currently assigned to Oncothyreon Inc.. Invention is credited to Myung-Gi Baek, Zi-Hua Jiang, Rao Koganty, Damayanthi Yalamati.
United States Patent |
7,741,297 |
Jiang , et al. |
June 22, 2010 |
Immunostimulatory, covalently lipidated oligonucleotides
Abstract
Covalently lipidated oligonucleotides comprising the CpG
dinucleotide unit, or an analogue thereof, may be used as
immunostimulatory agents to protect against a disease caused by a
cancer cell or a pathogen, either alone or in conjunction with
immunogens and/or non-immunological agents. Lipidated
oligonucleotides with special backbones, lipidated oligonucleotides
with fewer than eight nucleotides, and lipidated oligonucleotides
comprising a plurality of CpG dinucleotide-containing segments
connected by a long internucleoside linkage are of particular
interest. These compounds are also novel per se.
Inventors: |
Jiang; Zi-Hua (Alberta,
CA), Koganty; Rao (Alberta, CA), Yalamati;
Damayanthi (Alberta, CA), Baek; Myung-Gi
(Alberta, CA) |
Assignee: |
Oncothyreon Inc. (Seattle,
WA)
|
Family
ID: |
27734279 |
Appl.
No.: |
10/502,085 |
Filed: |
February 4, 2003 |
PCT
Filed: |
February 04, 2003 |
PCT No.: |
PCT/CA03/00135 |
371(c)(1),(2),(4) Date: |
April 12, 2005 |
PCT
Pub. No.: |
WO03/066649 |
PCT
Pub. Date: |
August 14, 2003 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20060189550 A1 |
Aug 24, 2006 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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60353195 |
Feb 4, 2002 |
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Current U.S.
Class: |
514/44R;
424/184.1 |
Current CPC
Class: |
A61P
35/00 (20180101); A61K 39/39 (20130101); A61P
31/00 (20180101); C07H 21/00 (20130101); A61K
39/0011 (20130101); A61P 37/00 (20180101); A61P
37/04 (20180101); A61P 33/00 (20180101); A61K
2039/55561 (20130101); A61K 2039/55555 (20130101) |
Current International
Class: |
A01N
43/04 (20060101); A61K 39/38 (20060101) |
Field of
Search: |
;424/184.1 ;514/44 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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10 251292 |
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Dec 1998 |
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JP |
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WO 98/18810 |
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May 1998 |
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WO |
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WO 98/40100 |
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Sep 1998 |
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WO |
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WO 99/51259 |
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Oct 1999 |
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WO |
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WO 99/61056 |
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Dec 1999 |
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WO |
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WO 00/54803 |
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Sep 2000 |
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WO |
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WO 01/07055 |
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Feb 2001 |
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WO |
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WO 01/12804 |
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Feb 2001 |
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WO |
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WO 01/83503 |
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Nov 2001 |
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WO |
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WO 01/97843 |
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Dec 2001 |
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WO |
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|
Primary Examiner: Navarro; Mark
Attorney, Agent or Firm: Cooper; Iver P.
Parent Case Text
This application is a nonprovisional of U.S. provisional appl.
60/353,195 filed Feb. 4, 2002, which is hereby incorporated by
reference in its entirety.
Claims
The invention claimed is:
1. A method of stimulating the immune system of a subject which
comprises administering to the subject an immunologically effective
amount of an isolated immunostimulatory molecule which comprises at
least one oligonucleotide strand which comprises (1) at least one
nucleotide sequence comprising a plurality of nucleotides, each
nucleotide comprising a nucleobase, and thereby also comprising at
least one CxG dinucleotide unit or analogue thereof, in which there
are no more than six nucleobases in each oligonucleotide strand,
wherein in said analogue, (1) cytosine is replaced with a cytosine
analogue which is a pyrimidine other than thymine or uracil, and/or
(2) guanine is replaced with a guanine analogue which is a purine
other than adenine, and (2) at least one covalently incorporated
lipophilic group.
2. The method of claim 1 in which element (1) comprises a CxG
dinucleotide unit.
3. The method of claim 1 in which the CxG dinucleotide unit is a
CpG dinucleotide unit.
4. The method of claim 1 in which there are 2-5 nucleobases on each
nucleotide strand.
5. The method of claim 4 in which at least one lipophilic group is
a strongly lipophilic group.
6. The method of claim 4 in which at least one lipophilic group is
a highly lipophilic (Meylan) group.
7. The method of claim 4 in which at least one lipophilic group has
a predicted logP, according to the Meylan algorithm, of at least
4.
8. The method of claim 4 in which at least one lipophilic group has
a predicted logP, according to the Meylan algorithm, of at least
7.
9. The method of claim 4 in which at least one lipophilic group has
a predicted logP, according to the Meylan algorithm, of at least
10.
10. The method of claim 4 in which at least one lipophilic group is
selected from the group consisting of
--(CH.sub.2).sub.4NH.CO--(CH.sub.2).sub.nCH.sub.3 (a) where n=an
integer with values ranging from 6 to 26, ##STR00076## where m and
n are independent integers with values ranging from 6 to 26, (c)
--XR wherein X is --O--, --S--, or --NH-- and --R is aliphatic, and
(d) --XR wherein X is --O--, --S--, or --NH-- and --R is at least
partially aromatic.
11. The method of claim 4 where --R is a group selected from the
group consisting of one of the following structures: ##STR00077##
where m, n, and k are independent integers with values ranging from
3 to 30.
12. The method of claim 4 in which at least one lipophilic group is
one of the lipophilic groups depicted below ##STR00078##
13. The method of claim 4 where said molecule comprises at least
two lipophilic groups.
14. The method of claim 12 where said molecule comprises at least
two strongly lipophilic groups.
15. The method of claim 12 where said molecule comprises at least
two highly lipophilic (Meylan) groups.
16. The method of claim 4 in which there are 2-4 nucleobases on
each nucleotide strand.
17. The method of claim 1 in which each of the nucleobases is
selected from the group consisting of adenine, guanine, thymine,
cytosine, uracil, and hypoxanthine.
18. The method of claim 1 in which each of the nucleobases is
selected from the group consisting of adenine, guanine, thymine,
and cytosine.
19. The method of claim 4 wherein at least one nucleotide comprises
a nucleobase-carbohydrate nucleoside.
20. The method of claim 19 in which the carbohydrate is a
monosaccharide.
21. The method of claim 19 in which the number of carbon atoms in
the monosaccharide is 3-8.
22. The method of claim 21 in which the monosaccharide is a
pentose.
23. The method of claim 20 in which the monosaccharide is an
aldose.
24. The method of claim 20 in which the monosaccharide is
cyclized.
25. The method of claim 19 in which the monosaccharide is a
pyranose.
26. The method of claim 20 in which the monosaccharide is a ribose
or a 2-deoxyribose.
27. The method of claim 4 in which all of the nucleotides of one
strand comprise a nucleobase-carbohydrate nucleoside.
28. The method of claim 4 in which at least one nucleotide further
comprises a phosphate.
29. The method of claim 28 in which at least one nucleotide
comprises one and only one phosphate.
30. The method of claim 29 in which at least one strand is DNA or
RNA.
31. The method of claim 4 in which at least one lipophilic group is
covalently incorporated into a free end of at least one strand.
32. The method of claim 4 in which at least one lipophilic group is
covalently incorporated into the 3' end of at least one strand.
33. The method of claim 31 in which the lipophilic group is
attached to the end through a phosphate group.
34. The method of claim 4 in which at least one lipophilic group is
incorporated into an internucleoside linkage.
35. The method of claim 4 in which at least one lipophilic group is
a substituent of a nucleobase.
36. The method of claim 15 in which at least part of the
oligonucleotide has a backbone which differs from that of DNA and
RNA.
37. The method of claim 36 in which the backbone differs in that
the internucleoside linkage is not a phosphate group.
38. The method of claim 36 in which the backbone differs in that at
least one nucleotide is a non-normal nucleotide which does not
comprise ribose or 2-deoxyribose.
39. The method of claim 38 in which the non-normal nucleoside
comprises a sugar.
40. The method of claim 38 in which the non-normal nucleotide does
not comprise a sugar.
41. The method of claim 40 in which the oligonucleotide is at least
partially a PNA oligomer.
42. The method of claim 40 in which at least one non-normal
nucleotide comprises a non-normal nucleoside of the form
nucleobase-O-alkyl where the --O-alkyl is the residue of a polyol,
and the alkyl is not more than 6 carbon atoms.
43. The method of claim 42 wherein the polyol is glycerol, and
hence the alkyl is 3 carbon atoms.
44. The method of claim 36 in which at least non-normal nucleoside
is bound to a phosphate group.
45. The method of claim 44 in which there are two adjacent such
non-normal nucleosides and the internucleoside linkage between them
is a phosphate group.
46. The method of claim 44 in which there are two adjacent such
non-normal nucleosides and the internucleoside linkage between them
is -phosphate group-linker Z-phosphate group-, where linker Z is
aliphatic.
47. The method of claim 46 in which linker Z is of the form -[small
alkyl-O].sub.n, where n is 1 to 20, and small alkyl is not more
than 6 carbon.
48. The method of claim 47 in which linker Z is
--[CH.sub.2CH.sub.2O].sub.n--.
49. The method of claim 4 in which the dinucleotide unit comprises
a non-natural nucleoside, or an internucleoside linkage which is
not a phosphate group.
50. The method of claim 4 in which the CxG dinucleotide unit
comprises two non-natural nucleosides and the internucleoside
linkage between them is a phosphate group.
51. The method of claim 49 in which the dinucleotide unit comprises
two non-natural nucleosides and the internucleoside linkage between
them is -phosphate group-linker Z-phosphate group-, where linker Z
is aliphatic.
52. The method of claim 51 in which linker Z is
--[CH.sub.2CH.sub.2O].sub.n-- and n is 1 to 20.
53. The method of claim 49 in which the dinucleotide unit is a PNA
oligomer.
54. The method of claim 49 in which the dinucleotide unit is a GNA
oligomer.
55. The method of claim 4 in which the molecule lacks double
stranded structure.
56. The method of claim 55 in which the molecule has at least some
double stranded structure.
57. The method of claim 3 in which there are no more than four
nucleobases in each oligonucleotide strand.
58. The method of claim 1 in which the molecule further comprises
at least one epitope, said epitope being a peptide, carboxydrate,
lipid, glycopeptide or glycolipid epitope.
59. The method of claim 58 wherein at least one epitope is a
carbohydrate epitope.
60. The method of claim 58 wherein at least one epitope is a
peptide epitope.
61. The method of claim 58 wherein at least one epitope is a B-cell
epitope.
62. The method of claim 58 wherein at least one epitope is a T-cell
epitope.
63. The method of claim 58 wherein at least one epitope is a MUC1
epitope.
64. The method of claim 1 in which the oligonucleotide is cyclized,
so as to lack a free end, and the lipophilic groups are
incorporated elsewhere in the molecule.
65. The method of claim 1 where said molecule which comprises two
or more segments, each segment consisting of nucleosides joined to
each other by short internucleoside linkages, each segment being
joined to at least one other segment by a long internucleoside
linkage, at least two of said segments each comprising at least one
CxG dinucleotide unit or analogue thereof.
66. The method of claim 65 in which said segments are connected by
said internucleoside linkages to form one or more linear
chains.
67. The method of claim 65 in which two or more segments are
cyclized by two or more internucleoside linkages.
68. The method of claim 1 where said nucleotide sequence comprises
at least one pair of adjacent thymine nucleobases which are
dimerized to form a thymine dimer.
69. The method of claim 4 in which at least one lipophilic group is
covalently incorporated into the 5' end of an oligonucleotide
strand.
70. The method of claim 4 in which the molecule does not have
cytotoxic activity against cancer cells.
71. The method of claim 4 in which the subject is not suffering
from a cancer.
72. The method of claim 4 in which the subject is not being
medicated with any other cancer preventative.
73. The method of claim 4 in which the molecule potentiates the
specific innate immune response to a pathogen or cancer already
present in the subject.
74. The method of claim 4 which further comprises administering a
pharmaceutical composition comprising an immunogen to the subject,
said molecule potentiating the specific elicited immune response to
said immunogen.
75. The method of claim 74 in which the molecule and the immunogen
are administered simultaneously.
76. The method of claim 75 in which the molecule and the immunogen
are administered in the same composition.
77. The method of claim 74 in which the immunostimulatory
oligonucleotide molecule is also an immunogen which elicits a
specific immune response protective against said pathogen or
cancer.
78. The method of claim 1 where none of the internucleoside
linkages is selected from the group consisting of poly(N-viny1),
poly(methacryloxyethyl), poly(methacrylamide), and
poly(etheylenimine)
79. The method of claim 1 wherein the nucleotide sequence consists
of two nucleotides.
80. The method of claim 1 wherein the nucleotide sequence consists
of three nucleotides.
81. The method of claim 1 wherein the nucleotide sequence consists
of four nucleotides.
82. The method of claim 1 wherein the nucleotide sequence consists
of five nucleotides.
83. The method of claim 1 wherein the nucleotide sequence consists
of six nucleotides.
84. The method of claim 1 wherein the nucleotide sequence consists
of seven nucleotides.
85. A method of stimulating the immune system of a subject which
comprises administering to the subject an immunologically effective
amount of an immunostimulatory molecule which comprises at least
one oligonucleotide strand which comprises (1) at least one
nucleotide sequence comprising a plurality of nucleotides, each
nucleotide comprising a nucleobase, and thereby also comprising at
least one CxG dinucleotide unit or analogue thereof, in which there
are no more than six nucleobases in each oligonucleotide strand,
wherein in said analogue, (1) cytosine is replaced with a cytosine
analogue which is a pyrimidine other than thymine or uracil, and/or
(2) guanine is replaced with a guanine analogue which is a purine
other than adenine, and (2) at least one covalently incorporated
lipophilic group.
86. The method of claim 1 wherein the molecule is immunostimulatory
in the absence of lipofectin.
87. The method of claim 1 wherein the stimulation of the immune
system comprises stimulation of T-cell proliferation.
88. The method of claim 76 in which the immunostimulatory molecule
and the immunogen are separate molecules.
89. The method of claim 4 in which the molecule further comprises
at least one epitope, said epitope being a peptide, carbohydrate,
lipid, glycopeptide or glycolipid epitope.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the use of covalently lipidated
oligonucleotides comprising the CpG dinucleotide unit, or an
analogue thereof, as immunostimulatory agents. Lipidated
oligonucleotides with special backbones, lipidated oligonucleotides
with fewer than eight nucleotides, and lipidated oligonucleotides
comprising a plurality of CpG dinucleotide-containing segments
connected by a long internucleoside linkage are of particular
interest.
2. Description of the Background Art
Effective host defense against invading microorganisms requires the
detection of foreign pathogens and the rapid deployment of an
antimicrobial effector response (Krutzik et al, 2001). Indeed, the
innate immune system detects the presence and the nature of the
infection by recognizing the constitutive and conserved products of
microbial metabolism, which can be viewed as molecular signatures
of microbial invaders (Janeway, 1992), and also called
pathogen-associated molecular patterns (PAMPs). PAMPs are
recognized by various pattern-recognition receptors (PRRs) of the
innate immune system, which are expressed on the cell surface, in
intracellular compartments, or secreted into the blood stream and
tissue fluids. Also, the innate immune system provides the first
line of host defense, and controls the initiation and determination
of the effector class of the adaptive immune response (Medzhitov,
2001).
Toll-Like Receptor Ligands
The recent discovery and characterization of the Toll-like receptor
(TLR) family have incited new interest in the field of innate
immunity. TLRs are also pattern-recognition receptors (PRRs) that
have a unique and essential function in animal immunity. In
mammalian species there are at least ten TLRs currently known
(Medzhitov, 2001), and each seems to have a distinct function in
innate immune recognition. Dozens of TLR ligands have been
identified (Akira et al, 2001).
Though quite diverse in structure and origin, TLR ligands have
several common features. For instance, most TLR ligands are
conserved microbial products (PAMPs) that signal the presence of
infection; and many individual TLRs can recognize several
structurally unrelated ligands. It is obvious that TLR ligands are
potent activators of innate immune system, which in turn directs
and determines the adaptive immune response.
CpG Motifs
Probably the most enigmatic example of pattern recognition is the
recognition of unmethylated CpG motifs in bacterial DNA by TLR9
(Hemmi et al, 2000). As a matter of fact, unmethylated bacterial
DNA in a particular sequence context (the so-called CpG motif) has
been known for its potent immune stimulatory activity for quite
some time (Krieg et al, Nature, 1995).
WO98/18810 (University of Iowa Research Foundation) teaches that
certain nucleic acids containing unmethylated CpG dinucleotides
activate lymphocytes in a subject and redirect a subject's immune
responses from a Th2 to a TH1, i.e., increase production of Th1
cytokines including IL-12, IFN-gamma and GM-CSF. In particular, it
discloses an isolated immunostimulatory nucleic acid sequence of
about 8-30 bases "represented" by the formula 5'
N.sub.1X.sub.1CGX.sub.2N.sub.2 3' where at least one nucleotide
separates consecutive CpGs; X.sub.1 is A, G or T, X.sub.2 is C or
T, N is any nucleotide, and N1+N2 is 0-26 nucleotides, with the
proviso that the latter does not contain a CCGG quadmer or more
than one CCG or CGG trimer. With respect to stimulation of murine
cells, a preference is expressed for a CpG flanked by two 5'
purines (preferably GpA) and two 3' pyrimidines (preferably TpT or
TpC).
The authors reported that oligomers shorter than 8 bases were
non-stimulatory (page 25, lines 16-17); the tested oligomer was a
7-mer (Table 1, 4e). See also Sonehara, et al., "Hexamer
Palindromic Oligonucleotides with 5'-CG-3' Motif(s) Induce
Production of Interferon," J. Interferon & Cytokine Res.,
16:799-803 (1996)(IFN-inducing activity of ACGT "insignificant").
In contrast, in the present invention, we have found that if
lipidated, even a dinucleotide by itself has activity.
WO98/40100 (Ottawa Civic Loeb Research Laboratory, Qi-Agen GmbH,
and University of Iowa Research Foundation), WO99/51259 (University
of Iowa Research Foundation), WO99/61056 (Loeb Health Research
Institute at the Ottawa Hospital, CPG Immunopharmaceuticals, Inc.)
have similar teachings. While WO98/40100 defines an oligonucleotide
as being at least five bases in length, it nonetheless teaches that
for the desired immunostimulatory activity, at least 8 bases are
needed. WO01/97843 says that the immunostimulatory nucleic acid can
have any length greater than 6 nucleotides (p. 7, l. 12).
WO99/61056 (p3, L30) implies that a hexanucleotide can induce
mucosal immunity, although an octanucleotide is preferred (p 8, l.
17).
WO01/12804 (Hybridon, Inc.) teaches that it is desirable that the
two bases immediately flanking the CpG on its 5' end be 2'-OMe
substituted.
WO01/97843 (University of Iowa Research Foundation) teaches that it
is desirable that the CpG oligonucleotide be "T-rich", i.e.,
greater than 25% T, more preferably, greater than 40%, 50%, 60%,
80% or 90% T. It teaches that it is desirable that it comprise at
least one poly-T motif consisting of at least three consecutive T
bases. It expresses a preference for longer poly-T motifs (at least
4-9 Ts) and for a plurality of poly-T motifs (at least 2-8).
Likewise, it discloses the desirability of poly-A, poly-C, and
poly-G motifs.
WO00/54803 (Panacea Pharmaceuticals, LLC) relates to use of the
CpG-containing oligonucleototides to ameliorate allergic responses
to immunogens. See also DeKruyff, U.S. Pat. No. 6,086,898 (2000),
on converting a Th2-type allergic immune response into a Th1-type
immune response.
WO01/07055 teaches use of a CpG-oligonucleotide having a particular
topology, for higher stability in vivo.
Lipoteichoic Acid; Doubse-Stranded Ribonucleic Acid
Structurally related lipo-teichoic acid (LTA) from Gram-positive
bacteria and double-stranded RNA (dsRNA) from viruses are also well
known for their properties of activating host innate immunity.
Recent studies have shown that TLR4 is involved in the recognition
of LTA (Takeuchi et al, 1999) and TLR3 functions as a cell-surface
receptor for dsRNA (Alexopoulou et al, 2001).
Teichoic acids are polyol phosphate polymers, with either ribitol
or glycerol linked by phosphodiester bonds. Substituent groups on
the polyol chains of the naturally occurring teichoic acids can
include D-alanine (ester-linked), N-acetylglucosamine, and glucose.
In the ribitol teichoic acids, there are 1,5-phosphodiester
linkages. In the glycerol teichoic acids, there are 1,2- or
1,3-phosphodiester linkages. The glycerol teichoic acids may be
unsubstituted, or substituted (e.g. alanyl or glycosyl) at the
remaining position.
Glycerol Nucleic Acids
Usman, Juby and Ogilvie, "Preparation of Glyceronucleoside
Phosphoramidite Synthons and Their Use in the Sold Phase Synthesis
of Acyclic Oligonucleotides" Tetrahedron Lett., 29: 4831-4 (1988)
descibes the synthesis of homooligomers (2-8 units long) of the
nucleotides in which either adenine or thymine are part of a
glyceronucleoside. It is noted in passing that glyceronucleosides
per se, especially those containing purines (adenine and thymine)
as the base component, are potent antiviral agents.
Schneider and Benner, "Oligonucleotides Containing Flexible
Nucleoside Analogues," J. Am. Chem. Soc. 112: 453-55 (1990)
disclose oligonucleotides in which ribose is replaced by a glycerol
derivative. However, they found that the change in backbone reduced
the ability of the oligonucleotide to form a stable duplex
structure. Each glycerol nucleoside reduced the melting point of
the duplex DNA by about 9-15.degree. C. The oligonucleotides
synthesized by Schneider and Benner were at least 9 bases long, and
none of them comprised 5'-CG-3'.
Other Oligonucleotide Analogues
Oligonucleotide analogues, especially those with modified
internucleoside linkages, are known in the art. See e.g. Cook, U.S.
Pat. No. 5,717,083; Weis, U.S. Pat. No. 5,677,439; Rosch, U.S. Pat.
No. 5,750,669; Cook, U.S. Pat. No. 6,114,513; Cook, U.S. Pat. No.
6,111,085; Uhlmann, et al., "PNA: Synthetic Polyamide Nucleic Acids
with Unusual Binding Properties," Angew. Chem. Int. Ed.
37:2796-2823 (1998).
Chemically Modified Nucleic Acids
Englisch and Gauss, "Chemically Modified Oligonucleotides as Probes
and Inhibitors", Angew. Chem. Int. Ed. Engl., 30: 613-29 (1991)
make reference to oligonucleotides modified to include psoralen,
acridine, biotin, or enzymes.
Known terminal radicals (hydroxyl substituents) include
1-ethoxyethyl, ethoxymethyl, benzhydryl, benzyl, trityl,
monomethoxytrityl, dimethoxytrityl, methyl, ethyl, acetyl, tosyl,
tetrahydropyranyl, trifluoroacetyl, aminoacyl, glycyl, leucyl,
cyanoethyl, anisyl, benzyl, and phenyl, and, as bifunctional
protecting groups (usually bridging 2' and 31),
Known terminal glycol-protecting (bifunctional) radicals, bridging
the 2' and 3' hydroxyls unless otherwise indicated, include
isopropylidene, borate, and carbonyl 2':3'-phosphate (cyclic).
N-protecting radicals used in synthetic work include benzoyl,
benzyl, tosyl, trityl, anisoyl, benzhydryl (diphenylmethyl),
monomethoxytrityl (p-anisyldiphenylmethyl), dimethoxytrityl
(di-p-anisylphenylmethyl), tetrahydropyranyl, dansyl, and
N-cyclohexyl-N'[-(4-methylmorpholino)amidino].
Phosphoric acid protecting groups include 5'-cyanoethyl; 3'(or
2')-cyanoethyl, anisyl (MeOPh), benzyl, and phenyl.
Lipidated Nucleic Acids
Hostetler, U.S. Pat. No. 5,827,831 teaches that oral delivery of
many clases of drugs is facilitated by converting drugs having
suitable functional groups to 1-O-alkyl, 1-O-acyl, 1-S-acyl, and
1-S-alkyl-sn-glycero-3-phosphate derivatives; he refers to these
derivatives as lipid prodrugs. The classes of drugs taught by
Hostetler include "anticancer agents, comprising nucleoside
analogues, for example, 9-beta-D-arabinofuranosylcytosine
(hereinafter, cytosine arabinoside or ara-C),
9-beta-D-arabinofuranosyladenine (hereinafter, adenine arabinoside
or ara-A), 5-fluorouridine, 6-mercaptopurine riboside, or
2'-ara-fluoro-2-chlorodeoxyadenosine", and "antiviral nucleosides,
particularly the 1-O-alkyl phospholipid derivatives of those
antiviral nucleosides disclosed in U.S. Pat. No. 5,223,263". In the
antiviral category, specific reference is made to 3'deoxy,
3'-azidothymidine (AZT), acyclovir, foscarnet, ganciclovir,
idoxuridine, ribavarin, 5-fluoro-3'-thia-2',3'-dideoxycytidine,
trifluridine, and vidarabine. There is no reference to lipidation
of any oligonucleotides.
Sridhar, U.S. Pat. No. 5,756,352 discloses thiocationic
lipid-nucleic acid conjugates. The cationic lipid binds
noncovalently to the anionic nucleic acid molecules. The present
invention requires covalent attachment of a lipophilic group to the
oligonucleotide.
Cheng, et al. U.S. Pat. No. 5,646,126 discloses double stranded
oligonucleotides having a lipophilic group, preferably a steroid
structure, attached to the 3' end. The oligonucleotides comprised
8-18 bases (per strand). They do not disclose or suggest any
shorter oligonucleotides, or any molecules without at least some
double-stranded structure.
Cheng et al. conceived of three types of molecules with double
stranded structure. In type 1, the oligonucleotide is palindromic,
so two molecules together form a duplex. In type 2, there are two
different but substantially complementary strands, which hybridize
to form the duplex. Finally, in type 3, the oligonucleotides are at
least partially self-complementary, so they "hairpin" to form a
double-stranded structure.
The oligonucleotides of interest to them were those with anticancer
activity. They do not disclose or suggest that any of his
oligonucleotides have immunostimulatory activity.
Several of these oligonucleotides (e.g., 120 H, 128 H, 001 H, 167
H, 002 H, 089 H, 589 H, 178 H, 678 H) comprise 5'-CG-3'. The 3'
modifications of sequence 128H (CACACGTGTG)(SEQ ID NO: 1) included
cholesterol*, hexylamine, acridine, hexanol, hexadecane,
cholestanol*, ergosterol, stigmastanol*, stigmasterol*, and
methyl-lithacholic acid; only the starred modifications had
anticancer activity (see Cheng FIG. 10). Thus, Cheng et al.
discouraged further experimentation with 3' lipophilic
modifications other than those with the steroid skeleton of his
Formula 1. Cheng et al. do not disclose or suggest any 5'
lipophilic attachments.
While Cheng et al. contemplated the possibility of backbone
modification, especially, phosphorothioate (P-S0 linkages, they did
not specifically suggest peptide-nucleic acid (PNA) or glycerol
nucleic acid (GNA) backbones. Indeed, since GNA backbones reduce
duplex stability, use of a GNA backbone would have been contrary to
Cheng et al.'s teaching of oligonucleotide duplexes.
Targeted Nucleic Acids
Manoharan, U.S. Pat. No. 6,300,319 discloses attaching a cell
surface receptor ligand to an oligonucleotide to facilitate
delivery of the oligonucleotide to the cell in question. Manoharan
notes that natural oligonucleotides are polyanionic and poorly
penetrate cells, while the methylphosphonates are neutral and are
taken up much more readily. The ligands contemplated by Manoharan
are primarily carbohydrates (targeting cell surface lectins) sch as
galactose, N-acetylgalactosamine, fucose, mannose, and sialic acid.
These would not be considered lipophilic groups (see Table K-2,
below).
SUMMARY OF THE INVENTION
The present invention relates to a method of stimulating the immune
system which comprises the administration of an oligonucleotide
which comprises (1) one or more "CxG" dinucleotide units (i.e., a
nucleotide presenting the nucleobase cytosine is linked directly to
a nucleotide presenting the nucleobase guanine), or an
immunostimulatory analog thereof, and (2) one or more covalently
attached (incorporated) lipophilic groups.
The presence of the CxG dinucleotide unit renders the
oligonucleotide a potential TLR ligand.
The lipophilic group can facilitate the penetration of the
oligonucleotide into a cell membrane, whether directly or through
incorporation of the lipidated oligonucleotide into a liposomal
drug delivery formulation. It may also interact with cell surface
lipid receptors.
We have discovered that even CxG-containing oligonucleotides of
less than five nucleobases have immunostimulatory activity, and we
credit this to the presence of the lipophilic group.
We have also discovered that the oligonucleotide may comprise an
alternative backbone, such as a glycerol-nucleic acid backbone, and
have immunostimulatory activity.
The oligonucleotides of the present invention may, but need not,
have the cytotoxicity for cancer cells sought by Cheng, and they
may be administered to persons in need of immune system stimulation
who are not suffering from cancer, as well as to those who are.
The present invention also relates to certain classes of lipidated
oligonucleotides, as compounds per se. (The term "lipidated
oligonucleotide" simply means an oligonucleotide having one or more
lipophilic groups, as hereafter defined.)
In one class, the number of nucleotides in the lipidated
oligonucleotides is less than eight (the smallest lipidated
oligonucleotide taught by Cheng, U.S. Pat. No. 5,646,126). Eight is
also the minimum number of nucleotides taught by WO98/18810 in
connection with unlipidated CpG-containing oligonucleotides taught
as immunostimulatory agents. More preferably it is less than five
nucleotides. Compounds 1-7 in FIG. 7 are non-limiting examples of
this class; compounds 1, 2, 6 and 7 are dinucleotides while
compound 3, 4 and 5 are hexanucleotides.
In a second class, the lipidated oligonucleotides comprise a
plurality of oligonucleotide segments, each of at least two of
these segments containing at least one "CxG" dinucleotide unit, and
at least two such "CxG"-containing segments being connected,
directly or indirectly, by a moiety which comprises a "long"
internucleoside linkage. A non-limiting example of such a
multisegment lipidated oligonucleotide, with two CpG-containing
segments connected by a long internucleoside linkage, appears in
FIG. 3.
In a third class, the lipidated oligonucleotides comprise, not only
at least one "CxG" dinucleotide unit, but also at least one pair of
adjacent thymine nucleobases that have dimerized together as shown
in FIG. 19.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1: Structure-activity relationship of unmethylated
CpG-containing nucleotide sequence
FIG. 1 recites, inter alia, a longer "D ODN" sequence (SEQ ID NO:
3).
FIG. 2: CpG dinucleotide modified at 3'-end with various lipophilic
groups.
FIG. 3: Modified CpG dinucleotide as divalent ligand; two segments,
each presenting a CpG.
FIG. 4: Hexanucleotide ATCGAT modified at 5'-end with a lipophilic
group.
FIG. 5: Comparison of structures of GNA (glycerol nucleic acid),
DNA, and PNA (peptide nucleic acid).
FIG. 6: Hexanucleotide GtcgTT modified at 3'-end with a lipophilic
group, wherein cg dinucleotide has glycerol-based nackbone.
FIG. 7: CpG-containing lipidated oligonucleotides with DNA
(compounds 1-5), GNA (6) and PNA (7) backbones.
FIG. 8: Building blocks for solid-phase nucleotide synthesis by
phosphoramidite method.
FIG. 9: Modification of long-chain amino alkyl controlled pore
glass (lcaa-CPG) resin for the synthesis of lipidated
oligonucleotides.
FIG. 10: Preparation of lipidated CpG dinucleotide 1 on solid
phase.
FIG. 11: Preparation of pentaerythritol-derived dilipo-alcohol 11
and its application for the synthesis of lipidated oligonucleotide
16.
FIG. 12: Preparation of glycerol-cytosine phosphoramidite 25.
FIG. 13: Preparation of glycerol-guanosine building block 32.
FIG. 14: Synthesis of glycerol-base CpG dinucleotide 6.
FIG. 15: Preparation of PNA-based CpG analogue 7 by standard solid
phase peptide synthesis using Fmoc/Bhoc chemistry.
FIG. 16: Immunostimulatory adjuvant properties of CpG analogues
1-6. In vitro antigen specific proliferation of T cells from
C57Bl/6 mice immunized with a single dose of BLP25 liposomal
vaccine formulation. The vaccine dose contains 20 .mu.g of
MUC1-derived 25-mer lipopeptide as an antigen and 10 .mu.g of one
of synthetic CpG analogues 1-6 as an adjuvant. The adjuvant R595
lipid A (detoxified lipid A product isolated from Salmonella
minnesota R595) is used for comparison.
FIG. 17: The first sequence is SEQ ID NO:11. The second structure
is the structure of lipopeptide BP1-148, comprising a modified 25
amino acid sequence (SEQ ID NO:2) derived from tumor-associated
MUC1 mucin. SEQ ID NO:2 corresponds to AAs 1-25 of SEQ ID NO:11,
and to AAs 14-20, followed by AAs 1-18, of the MUC1 tandem repeat
as set forth in SEQ ID NO:10.
The aforementioned BLP25 liposomal vaccine formulation is this
lipopeptide in combination with one of the aforementioned
adjuvants.
FIG. 18: A branched, three segment oligonucleotide with a long
multivalent internucleoside linkage comprising a pentaerythritol
element. The oligonucleotide further comprises a cholesterol
residue as a lipophilic group.
FIG. 19: CpG-containing oligonucleotides, with flanking bases,
lipidated at 3' end. Last oligonucleotide is SEQ ID NO:3.
FIG. 20: lipidated oligonucleotide cyclized by long internucleoside
linkage comprising lipophilic groups.
FIG. 21: Lipidated oligonucleotide comprising thymidine dimer as
well as CpG dinucleotide.
FIG. 22: Lipidated oligonucleotides with GNA backbone.
FIG. 23: Structures derived from lipoteichoic acid.
FIG. 24: Modified lipoteichoic acid backbone, wherein the ester
linkage between the D-alanine and the secondary hydroxyl group of
glycerol unit is replaced by an amide bond. This is expected to be
more resistant to hydrolysis.
FIG. 25: LTA/GNA and LTA/DNA hybrids.
FIG. 26: Oligo (I:C). Lipidated oligo-inosinic and oligo-cytidylic
acid may form double stranded complex and mimic the function of
dsRNA, which is a ligand for TLR-3. While not shown, the
oligonucleotide may additionally comprise CpG, or this
oligonucleotide may be used in its own right as an additional
adjuvant.
FIG. 27: Oligonucleotide comprising self-complementary regions. In
figure, one segment is oligo-inosinic acid and a second segment is
oligo-cytidylic acid, joined by a long internucleoside linker. The
strand hairpins at the linker to form the double stranded secondary
structure. The variable n is 0-6. While not shown, the
oligonucleotide may additionally comprise CpG, or this
oligonucleotide may be used in its own right as an additional
adjuvant.
FIG. 28: Oligonucleotide comprising self-complementary regions.
Oligonucleotide comprises two I(CI).sub.nC segments. These
complement each other when oriented and aligned as shown in inset
drawing. The variable n is 0 to 4; in the inset drawing, n=3. While
not shown, the oligonucleotide may additionally comprise CpG, or
this oligonucleotide may be used in its own right as an additional
adjuvant.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE
INVENTION
The immunostimulatory molecules of the present invention are
modified oligonucleotides. These oligonucleotides comprise at least
one CxG dinucleotide (preferably, a CpG dinucleotide) as defined
below, or an analogue thereof, and at least one covalently
incorporated lipophilic group. The lipophilic groups(s) may be
attached to the free end(s) of the oligonucleotide, or internal to
the oligonucleotide. The oligonucleotides may be linear, cyclic or
branched, and may include non-nucleic acid moieties (including, but
not limited to, lipophilic groups). The nucleotides are not limited
to the nucleotides normally found in DNA or RNA.
Molecules
A molecule is a chemical entity consisting of a plurality of atoms
connected by covalent or noncovalent bonds. Thus, in a
double-stranded DNA molecule, there are two oligonucleotide
strands, held together by noncovalent base pairing to form a
duplex. This duplex is considered a single molecule. If the duplex
is dissociated, then each strand is considered a molecule in its
own right.
Linkers and Linking Agents
In discussing the synthesis of molecules, it is helpful to
distinguish between a "linker" and a "linking agent". A "linking
agent" is a unitary molecule with at least two reactive functional
groups. After reaction with two (or more) target molecules (the
same or different), it forms a new molecule of the form "substrate
residue-linker-substrate residue". Thus, the linker is the residue
of the linking agent after it has accomplished its mission.
Immunostimulatory Molecules
The term "immunostimulatory oligonucleotide" shall mean an
immunostimulatory molecule which comprises at least one
oligonucleotide strand.
A molecule is considered immunostimulatory if it stimulates
immunocytes in any manner. For example, it may stimulate cytokine
(e.g., IL-1, IL-2, IL-4, IL-5, IL-6, IL-7, IL-10, IL-12, IL-15,
IFN-gamma, TNF-alpha, G-CSF, GM-CSF, TGF-beta, FLT-3 ligand, CD40
ligand) production by, e.g., lymphocytes; it may stimulate natural
killer cell lytic activity; it may stimulate B-cell or T-cell
proliferation, antibody production, etc.
Preferably, the molecule causes T-cell proliferation. However, it
may immunostimulate the immune system of a subject according to any
art-recognized measure of immunostimulatory activity. See the
section "Characterizing the Immune Response" of this disclosure, as
well as WO98/18810 P20, L15-21, L26-P21, L3 and the references
Krieg et al. 1995 (B-cell activation), Alexopoulo et al. 2001
(NF-.kappa.B activation, production of type I interferon), Hemml et
al., 2000 (cytokine production from macrophages and presensitized
lymph nodes), Takeuchi et al. 1999 (production of IL6, nitric oxide
and TNFalpha by macrophages; B cell proliferation and MHC class II
expression; activation of serine/threonine kinase IRAK); for
various measures of immunostimulatory activity.
An immunostimulatory molecule may be immunostimulatory in some
respects and immunosuppressive in other respects.
The term "immunostimulatory oligonucleotide" shall mean an
immunostimulatory molecule which comprises at least one
oligonucleotide strand.
The immunostimulatory oligonucleotides of the present invention may
be used in conjunction with other immunostimulatory molecules.
The immunostimulatory oligonucleotides may, but need not, be
presented in a liposome.
The immunostimulatory molecule may be used without a
pharmaceutically administered immunogen to potentiate the innate
immune response to a disease-associated immunogen, whether already
presented (in which case the use is a treatment), or which the
subject is at risk of experiencing (in which case the use is
prophylactic).
The immunostimulatory oligonucleotides may be used in conjunction
with a pharmaceutically administered immunogen. The immunogen
elicits a specific immune response to one or more epitopes; the
immunostimulatory oligonucleotide acts as an adjuvant, potentiating
that immune response in a nonspecific way. Hence, the
immunostimulatory oligonucleotide may be used with any
immunogen.
In some embodiments, the immunostimulatory oligonucleotide and the
immunogen are the same molecule, that is, the immunogen comprises
the oligonucleotide as a moiety, as well as the specific epitope(s)
of interest. The oligonucleotide may then be lipidated either
directly (the lipophilic group is directly attached to
(incorporated into) a nucleotide), or indirectly, e.g., attached to
the peptide moiety.
In a preferred embodiment, the epitope of the immunogen is a MUC1
peptide epitope. If the immunogen comprises the oligonucleotide, it
is then especially preferred that the backbone of the
oligonucleotide moiety be at least partially a PNA oligomer.
Alternatively, the oligonucleotide moiety could be attached to the
peptide moiety (comprising the epitope)
Oligonucleotides
An oligonucleotide is an oligomer wherein the monomeric unit is
called a nucleotide, or mononucleotide. An oligonucleotide
comprises two or more mononucleotides. It may comprise any number
of non-nucleotide chemical moieties, and indeed the
oligonucleotides of the present invention must at least bear a
lipophilic group. The oligonucleotides of the present invention are
also heterooligomers, because they comprises a "CxG" dinucleotide
unit, or analogue thereof.
An oligonucleotide may be considered to comprise
(1) a series of mononucleotides;
(2) a series of mononucleosides, with each adjacent pair connected
by an internucleoside linker; or
(3) a series of nucleobases, with each adjacent pair connected by
an interbase linker.
The term "comprise" is used because the oligonucleotide of the
present invention must also include at least one lipophilic group,
and may also include other chemical moieties, such as one or more
amino acid residues, one or more carbohydrates not attached to a
nucleobase, and so forth.
Nucleotides
A nucleotide, for the purpose of the present invention, is a
monomeric unit which comprises (1) a nucleobase as defined below,
and (2) linking means for linking the nucleobase of the instant
nucleotide directly or indirectly to the corresponding (but not
necessarily identical) linking means of at least one adjacent
nucleotide (if any). (This linking means may be called the
vertebral element; since, collectively, these vertebral elements
are called the backbone.) This definition is deliberately broader
than the conventional IUPAC definition of a nucleotide.
The vertebral elements of the oligonucleotide may be the same as
that of DNA or RNA, or different, in which case they form what is
called an "alternative backbone." The vertebral elements may be the
same for all nucleotides, or they may vary, leading to a hybrid
backbone.
If the oligonucleotide strand is linear, as in the case of DNA and
RNA, or is cyclic, then the linking means (vertebral element) will
be a trivalent means, with one valence connecting to the
nucleobase, and the other two valences directly connecting to the
linking means (vertebral elements) of the prior and subsequent
nucleotides in the sequence, if any (note that the oligonucleotide
can be a dinucleotide, in which the vertebral elements will each
have one free valence).
If the oligonucleotide strand is branched, then the linking means
instead may be a divalent means which links the nucleobase to a
branching core means. Each branching core means is linked to at
least two vertebral elements, and thus serves to indirectly connect
such elements. The demarcation between the linking means of each
nucleotide, and the branching core means, may be somewhat
arbitrary.
In DNA and RNA, each nucleotide consists essentially of a
nitrogenous base (the nucleobase), a sugar, and a phosphate group
attached to the 5' carbon of the sugar. The sequence diversity of
DNA and RNA is attributable to position-to-position variation of
the nitrogenous base. In DNA, the base is adenine, guanine,
cytosine or thymine. In RNA, thymine is replaced by uracil.
Collectively, these five bases are referred to herein as normal
nucleobases. Abnormal nucleobases may be used and are further
discussed below.
The corresponding normal nucleotides, which each further comprises
a sugar and a phosphate group, are properly called adenylic acid
(AMP), guanylic acid (GMP), cytidylic acid (CMP), thymidylic acid
(TMP), and uridylic acid (UMP). However, it is not unusual for them
to be identified by reference to the corresponding base (A, C, G,
T, U).
For proper nucleic acid nomenclature, see IUPAC-IUB Commission on
Biochemical Nomenclature (CBN), "Abbreviations and Symbols for
Nucleic Acids, Polynucleotides and their Constituents",
Recommendations 1970, www.chem.gmul.ac.uk/iupac/misc/naabb.html.
However, we do at times depart from the conventional nomenclature
for simplicity of description of certain analogues of DNA and RNA
contemplated herein.
The DNA or RNA sugar is a pentose, with a five-membered ring (four
carbons and one oxygen), and is ribose in the case of RNA and
2-deoxyribose in the case of DNA. These are considered normal
sugars. Abnormal sugars may be used and are further discussed
below. Non-carbohydrate moieties may also be used, in place of
sugars.
The base-sugar component of the DNA or RNA nucleotide is called a
nucleoside. The normal nucleosides of DNA and RNA are called
adenosine, guanosine, cytidine, thymidine and uridine.
In the present invention, the nucleosides may be non-normal. The
abnormality may take the form of the use of a non-normal
nucleobase, the use of a non-normal sugar-equivalent, or the use of
a non-normal attachment of the nucleobase to the sugar equivalent.
In DNA and RNA, the nucleobase is connected to the sugar by virtue
of a glycosidic bond from the N-3 of a pyrimidine base or the N-9
or a purine base.
The phosphate group provides the normal internucleoside linkage of
DNA and RNA. Abnormal internucleoside linkages may be used and are
further discussed below.
One may also visualize an interbase linker. In DNA and RNA, the
interbase linker is sugar-phosphate-sugar. These interbase linkers
are overlapping.
Topology of Interbase and Internucleoside Linkages
The topology of the interbase linkages in DNA and RNA may be
described as an inverted "Y" topology. Each nucleobase is directly
linked to a single sugar, each sugar is linked to two phosphate
groups. The interbase linkers are sugar-phosphate-sugar, and are
overlapping. The internucleoside linkers are phosphate groups, and
are discrete. The sugars and/or phosphates may of course be
replaced by other chemical moieties which preserve the "Y"
topology, as in a GNA or PNA oligomer.
The oligonucleotides of the present invention may have other
topologies. In a "V" topology, each nucleobase has two attachment
sites. The first attachment site of one nucleobase is joined to the
second attachment site of an adjacent one by a linker. This
interbase linker takes the place of both the sugar and the
phosphate in DNA and RNA. The interbase linkers in a "V" topology
are discrete. In a "V" topology, the nucleoside is just the
nucleobase and the internucleoside linker is the same as the
interbase linker.
Nucleobases (Nitrogenous Bases)
The term "nucleobase" refers to a nitrogenous base that can be
incorporated into a nucleotide which, in turn, is incorporated into
an oligonucleotide.
The nucleobase is preferably a purine or a pyrimidine, although it
may be an analogue thereof. In natural DNA, the purine is adenine
(A) or guanine (G), and the pyrimidine is cytosine (C) or thymine
(T). In natural RNA, uracil (U) appears instead of thymine. Nucleic
acids have been prepared in which the nitrogenous base is one other
than the five mentioned above, see, e.g., the abnormal bases listed
in 37 CFR .sctn. 1.822(p)(1).
The pyrimidines have a six-membered ring, and, in DNA and RNA, it
is N-3 which is directly bound to the sugar. Substitutions on N-2,
C-2, C-4, C-5 and C-6 are possible.
Substituents are functional groups attached to a ring atom. The
substituents are preferably fewer than six atoms other than
hydrogen. Possible substituents include halogen (fluoro, chloro,
bromo, iodo), alkyl, vinyl (--CH.dbd.CH2), allyl (--CH2CH.dbd.CH2),
carboxy (--COO.sup.-), formyl (--CH.dbd.O), hydroxy (--OH), oxy (or
oxo) (.dbd.O), thio (--SH), sulfono (--SO3 H), thioxo (.dbd.S),
selenoxo (.dbd.Se), amino (--NH2), aminooxo (.dbd.NH), cyano, nitro
(--NO2) and nitroso (--N.dbd.O) functional groups, and further
substituted forms obtained by combinations thereof, such as
haloalkyl, hydroxyalkyl, alkoxy (--OR), aminoalkyl (--NHR or
--NR2), alkylallyl, and thioalkyl (--SR). R is preferably methyl,
ethyl, isopropyl, n-propyl, isobutyl, n-butyl, sec-butyl or
tert-butyl.
There may be zero, one, two, three, four or five independently
chosen substituents.
Cytosine is 2-oxy, 4-amino-pyrimidine. Thymine is 2,4-dioxy,
5-methylpyrimidine. Uracil is 2,4-dioxy pyrimidine.
The purines have fused five and six membered rings, and, in DNA and
RNA, it is the N-9 which is directly bound to the sugar.
Substitutions on N-1, X-2, N-3, C-8, N-7, and C-6 are possible. The
possible substituents are the same as for the pyrimidines. There
may be 0-6 substituents.
Adenine is 6-Amino-purine. Guanine is 2-Amino-6-oxy-purine.
Alternative purines of particular interest include hypoxanthine
(6-oxypurine), xanthine (2,6-dioxypurine), and orotic acid
(2,4-dioxy, 6-carboxypurine).
In addition, one may have aza (N replaces C), deaza (C replaces
N),
CxG Dinucleotide Units
The olionucleotides of the present invention comprise at least one
"CxG" dinucleotide or an analog thereof. The term "CxG"
dinucleotide indicates that a first nucleotide which comprises the
base cytosine (C) is attached, by a linker denoted "x", to a second
nucleotide which comprises the base guanine (G). It is not
necessary that the linker "x" comprise a phosphate group or that
the nucleotides comprise a sugar moiety.
The "CxG" dinucleotide is preferably a "CpG" dinucleotide. The term
"CpG" dinucleotide indicates that a first nucleotide which
comprises the base cytosine (C) is attached, by a linker comprising
a phosphate group (p), to a second nucleotide which comprises the
base guanine (G). It is not necessary that the nucleotides be
phosphate-sugar nucleotides as in DNA or RNA. If they are DNA or
RNA nucleotides, then it will be understood that the orientation is
5'-CpG-3'.
Alternatively, the cytosine of the CxG (including CpG) dinucleotide
may be replaced with a cytosine analogue, which is a pyrimidine
more similar to cytosine than to thymine or uracil. Cytosine
differs from thymine and uracil as follows: (1) at the 1-6
positions, cytosine has --N.dbd.C(NH2)- and thymine (and uracil)
have --HN--C(.dbd.O)--; (2) at position 5, cytosine is
unsubstituted and thymine is methylated. A cytosine analogue
preserves these distinctions. However, the cytosine analogue is
preferably not 5-methylcytosine, as this methylation is known to
greatly reduce the immunostimulatory effect in unlipidated CpG
oligonucleotides.
Likewise, the guanine of the CxG (including CpG) may be replaced
with a guanine analog, which is a purine more similar to guanine
than to adenine. Guanine differs from adenine in that (1) at the
1-6 positions, guanine has --HN--C(.dbd.O)-- and adenine has
--N.dbd.C(NH2)-; and (2), at the 2 position, guanine is aminated
and adenine is unsubstituted. A guanine analogue preserves these
distinctions. Preferably, the guanine analogue is not a methylated
derivative of guanine.
If either or both of these replacements are made, we obtain an
analogue of the "CxG" (or "CpG") dinucleotide.
The CxG dinucleotide may have a standard DNA or RNA backbone (which
is a special case of the CpG dinucleotide), or it may have an
alternative backbone. The alternative backbone may be confined to
the CpG linkage, or it may occur elsewhere in the oligonucleotide
as well.
The immunostimulatory oligonucleotide may comprise a plurality of
CxG (especially CpG) dinucleotides. See, e.g., FIG. 3. The CxG may
be adjacent or non-adjacent.
Overall Base/Nucleoside Sequence
We here use the symbols A, C, G, T and U merely to identify a
nucleoside comprising a particular nucleobase; the nucleoside does
not necessarily comprise ribose or 2-deoxyribose as in DNA or
RNA.
The bases, if any, flanking the CxG on its 5' end (or what would be
considered the 5' end if the oligonucleotide were DNA) are
preferably AT, GA, or GT. The bases, if any, flanking the CxG on
its 3' end (or what would be considered the 3' end if the
oligonucleotide were DNA) are preferably TA, TT, or AT.
These flanking bases may be modified (non-normal) bases as taught
by WO01/12804.
In the embodiments in which the CxG dinucleotide is flanked by
other nucleotides, the most preferred sequences are those
comprising one or more copies of (A) a K motif, which activates
monocytes and B cells, and stimulates secretion of IL-6, such as
TCGTA or TCGTT, and (B) a D motif, which activates NK cells and
secretion of IFN-gamma, such as a palindromic sequence like ATCGAT.
Sequences of particular interest include GTCGTT (optimal in human),
GACGTT (optimal in mouse), and
TABLE-US-00001 GGTGCATCGATGCAGGGGGG. (SEQ ID NO: 3)
The oligonucleotide may be T-rich as taught by WO01/97843.
A special case of nucleobase modification is that of a thymine
dimer. In DNA, two adjacent thymidine nucleosides (TT) may dimerize
in situ so that the single six membered ring of each is joined into
a new fused polyaromatic structure having two six membered rings
joined by a fused four membered ring. This is called a thymidine
dimer. However, since the same reaction could occur between two
non-normal nucleosides having thymine nucleobases, it may more
generally be called a thymine dimer.
Thymidine dimerization occurs in nature as a result of ultraviolet
damage to DNA. It is believed that the immune system is sensitive
to the formation of thymidine dimers for this reason. Hence, by
deliberately incorporating a thymine dimer into the base sequence,
we can enhance the immune response elicited by the oligonucleotide.
Formation of a thymine dimer can be represented by
TABLE-US-00002 | | T T
Oligonucleotide Length
The art has generally taught that immunostimulatory
oligonucleotides comprise CpG and are at least five, six or eight
bases in length (per strand, if double stranded). While the present
invention includes these ranges as embodiments (we distinguish the
art in that we further teach inclusion of a lipophilic group), we
have found that even a dinucleotide, when lipidated, has activity
(cp. FIGS. 7 and 16). Hence, the present invention also includes
oligonucleotides wherein the number of nucleobases on one strand is
less than eight, i.e., two, three, four, five, six or seven.
The maximum number of nucleobases in the oligonucleotides of the
present invention is 100, more preferably 50, still more preferably
30, even more preferably 20, most preferably 10. The preferred
embodiments of the invention include any rational combination of
the preferred minima and preferred maxima set forth above.
The lipidated oligonucleotides with fewer bases than those of the
unlipidated oligonucleotides used by the art, i.e., those with 2-5
or 2-4 bases, are of particular interest.
Strandedness
The molecules of the present invention may be single- or
double-stranded. To be double stranded, the two strands must
feature sequences of substantially complementary bases (A:T, C:G,
etc.) and the backbones must be compatible with the formation of a
stable duplex.
A molecule is considered to be double stranded if it has two
strands which are at least partially complementary. Hence, a double
stranded molecule may be partially double stranded, or completely
double stranded. A molecule may be a partially double stranded
molecule because one strand is longer than the other, or because
aligned bases in the strands do not hydrogen bond to each
other.
A molecule has double stranded structure if (1) it is an at least
partially double stranded molecule, or (2) it is at least partially
self-complementary and thereby has a stable double stranded
secondary structure as a result of the folding of a single
strand.
When the molecule is at least partially double stranded, in a
preferred embodiment, one strand comprises two or more
hypoxanthines (hypoxanthine is the base corresponding to the
nucleoside inosine, I.) and the other strand comprises two or more
complementary cytosines. More preferably, there are no more than 21
such base pairs. The resulting oligo (I:C) moiety is intended to
mimic the TLR-3 ligand activity of dsRNA.
This I:C pairing can be achieved in a number of ways. For example,
one strand may comprise I.sub.n and the other C.sub.n. Another
double stranded embodiment of interest is one in which one strand
comprises (IC).sub.n, and the other, (CI).sub.n, so that I:C base
pairing occurs. Other arrangements of I and C to achieve I:C base
pairing are possible.
If the molecule will be used in single stranded form, it may be
designed to include regions which are self-complementary to each
other, so that the oligonucleotide will tend to fold so that these
regions form secondary structures. These secondary structures may
protect the nucleotide from enzymatic degradation.
While the strands of a double stranded molecule are normally held
together by noncovalent bonds (Watson-Crick base pairing as a
result of hydrogen bonding), it is possible to stabilize the duplex
by an internucleoside linkage which joins a 5' end of one strand to
the proximal 3' end of the other strand (after which the ends in
question are no longer free ends). This can be done with just one
pair of ends, or with both of them. In like manner, a single
stranded molecule which folds as a result of self-complementarity
can have its folded structure stabilized by such a linkage. In
either case, a lipophilic group may be incorporated into this
linkage.
Alternatively, the molecule may be single stranded and designed to
avoid formation of stable secondary structures.
In general, double stranded structure provides greater resistance
to degradation during delivery and single stranded structure
provides greater innate activity once delivered successfully.
Alternative Backbones
The oligonucleotides of the present invention may, but need not, be
characterized by the occurrence of one or more "alternative
backbones" (i.e., backbones other than those of DNA or RNA) in some
or all of the oligonucleotide. Alternative backbones may be used to
make the oligonucleotide more resistant to enzymatic degradation,
or to achieve other useful effects.
An alternative (abnormal) backbone may be provided by introducing
one or more abnormal internucleoside linkages, or by replacement of
the normal sugar with an abnormal moiety.
DNA, RNA and LTA are basically di-phosphate ester polymers with
slightly different building units (deoxyribose for DNA, ribose for
RNA, and glycerol for LTA), therefore, as PAMPs they are
structurally closely related to each other. Since their immune
activation properties are all mediated by the same group of
receptors--TLRs, it is reasonable to group these TLR ligands into
the same type of molecular structures. Furthermore, it seems that
the ligand specificity requirement of TLRs is relatively low; thus,
we perceive that the hybrid structures of DNA, RNA, LTA, and/or
glycerol-based nucleic acid (GNA) might well be potential ligands
for multiple TLRs.
Sugar and Phosphate Replacements
The normal vertebral element is composed of a "sugar-equivalent"
and a "phosphate equivalent". The "sugar-equivalent" is any
chemical moiety that serves the same structural role as the sugar
moiety of DNA or RNA, i.e., linking the nucleobase to the
"phosphate equivalent". It includes, but is not limited to, the
normal sugar moieties 2-deoxyribose and ribose. Likewise, the
"phosphate equivalent" is any chemical moiety that serves the same
structural role as the phosphate moiety of DNA or RNA, i.e.,
linking the "sugar equivalents" of adjacent nucleosides. It
includes, but is not limited to, the normal phosphate moiety.
In general, there is no difficulty identifying the sugar equivalent
if the phosphate equivalent remains phosphate, or identifying the
phosphate equivalent if the sugar equivalent remains a sugar.
However, if both are varied simultaneously, then an arbitrary
demarcation is necessary.
The following is suggested: (1) identify the longest chain of atoms
in the oligonucleotide strand (or segment thereof, if it is
segmented and branched) in question; (2) identify the shortest
chain of atoms leading from the nucleobase in question to that
chain of (1); and (3) identify the point at which chain (2) is
attached to chain (1). The sugar equivalent corresponds to all of
chain (2), including any side groups and the attachment site, plus
any atom of chain (1) which is (a) a member of the same ring as the
attachment site atom (DNA and RNA attach to the nucleobase to the
main chain of the oligonucleotide via two ring atoms of the sugar),
or (b) immediately adjacent to the attachment site and not a group
VI atom (e.g., oxygen).
By this definition, the sugar equivalent in DNA and RNA is simply
the sugar; the sugar equivalent in the glycerol nucleic acid of
FIG. 5 is the glycerol residue --CH2-CH(--O--)--CH2-; and the sugar
equivalent of the peptide nucleic acid of FIG. 5 is the
--CH2-N(--C(.dbd.O)CH2-)--CH2-.
The phosphate equivalent can then be identified as the remainder of
the vertebral element; it is the phosphate group for the DNA and
GNA of FIG. 5, and the --C(.dbd.O)--NH--CH2- for the PNA of FIG. 5.
These are also the internucleoside linkers for those molecules.
That is, the internuceloside linkage joins the sugar equivalent of
one nucleoside to the sugar equivalent of another.
Where the oligonucleotide has a V-topology, the interbase linker
may be considered both the sugar-equivalent and the
phosphate-equivalent for the purpose of the claims.
Internucleoside Linkages
The normal internucleoside linkage is
##STR00001## Note that in this structure, the oxygen labeled 3' is
the one which, in DNA and RNA, attaches to the 3' carbon of a
nucleoside sugar, and the one labeled 5' is the one which likewise
attaches to the 5' carbon of another nucleoside sugar. These two
oxygens, together with the phosphorus atom, may be called the main
chain atoms, because they lie on the longest chain of the
oligonucleotide (or oligonucleotide segment, if the molecule has
segments and is branched). The other two oxygens are side chain
atoms as they are not part of the most direct connection between
nucleosides.
Variations of the inter-nucleoside linkage can be characterized as
(1) those which affect only the main chain, (2) those which affect
only side chains, and (3) those which affect both.
Where there is a side chain modification, the number of
non-hydrogen atoms in the side chains may remain unchanged. For
example, the doubly bonded oxygen may be replaced by .dbd.S,
.dbd.Se, or .dbd.Te, and/or the singly bonded oxygen may be
replaced by a monovalent radical with a single non-hydrogen atom
such as --CH3, --NH2, --OH, --SH, --SeH, --TeH, or --X.
Alternatively, one or more of the side chains may be a larger
substituent. Such substituents include, but are not limited to,
those mentioned in connection with nucleobases. The substituent is
preferably an organic constituent composed of not more than 50
non-hydrogen atoms (more preferably not more than 25, still more
preferably not more than 10, most preferably not more than 5),
selected from the group consisting of carbon, silicon, oxygen,
nitrogen, sulfur, selenium, tellurium, phosphorus, and boron. The
substituent may be, or include, a lipophilic group, especially a
strongly or highly lipophilic group as defined elsewhere in this
disclosure.
Where there is a main chain modification, the number of
non-hydrogen atoms may remain unchanged. Thus, either oxygen
(--O--) may be replaced independently with --CH2-, --NH--, --S--,
--Se--, or --Te--.
Likewise, the phosphorus atom may be replaced. If the valency of
the replacement atom is less than that of the phosphorus atom, this
will compel elimination or modification of the side chain oxygens.
The replacement atom may be, e.g, boron, carbon, silicon, or
nitrogen.
The main chain may also be modified in order to lengthen it, with
or without retaining the original oxygen and phosphorus atoms
thereof. Such modifications involve inclusion of one or more
lengthening moieties, which preferably are independently chosen
from the group consisting of --CH2-, --CHZ-, --NH--, --NHZ-, --O--,
--C(.dbd.O)--, --C(.dbd.S)--, --C(.dbd.Se)--, --C(.dbd.Te)-- and
--PO4-, where Z is a halogen or an organic constituent composed of
not more than 50 non-hydrogen atoms (more preferably not more than
25, still more preferably not more than 10, most preferably not
more than 5) selected from the group consisting of carbon, silicon,
oxygen, nitrogen, sulfur, selenium, tellurium, phosphorus, and
boron.
Alternative linkages include the following:
##STR00002## (where the R.sub.s are hydrogen and/or alkyl)
##STR00003## (where R is hydrogen or alkyl)
##STR00004##
Possible replacements for the 3'-O--P--O-5' main chain include
3'-O--CH.sub.2C(.dbd.O)--O-5', 3'-O--C(.dbd.O)--NH-5', and
3'-CH.sub.2CH.sub.2CH.sub.2S--CH.sub.2-5'.
The entire nucleic acid molecule may be formed of such modified
linkages, or only certain portions may be so affected.
Nucleic acid molecules suitable for use in the present invention
thus include but are not limited to methylphosphonates, see Mill,
et al., Biochemistry, 18:5134-43 (1979), phosphorothioates, see
Matsukura, et al., Proc. Nat. Acad. Sci., 84:7706-10 (1987),
oligodeoxynucleotides covalently linked to an intercalating agent,
see Zerial, et al., Nucleic Acids Res., 15:9909-19 (1987),
oligodeoxynucleotide conjugated with poly(L-lysine), see Leonetti,
et al., Gene, 72:32-33 (1988), and carbamate-linked oligomers
assembled from ribose-derived subunits, see Summerton, J.,
Antisense Nucleic Acids Conference, 37:44 (New York 1989).
Boranophosphates, formacetals, siloxanes, dimethylenethiolates,
sulfoxidates and sulfonates are also known in the art.
For a general review, see Uhlmann and Peyman, `Antisense
Oligonucleotides: A New Therapeutic Principle," Chem. Revs.,
90:544-84 (1990). They discuss oligonucleotides with a modified
internucleotide phosphate residue in which a phosphate oxygen not
involved in the bridge is replaced (methylphosphonates,
phosphorothioates, phosphorodithioates, phosphoroamidates, and
phosphate esters), oligonucleotides in which a phosphate oxygen
involved in the bridge is replaced (bridged phsophoramidates,
bridged phosphorothioates, bridged methylenephosphates), and more
radical phosphate replacements such as siloxane, carbonate,
carboxymethylester, acetramidate, carbamate, and thioether
bridges.
They also discuss the possibility of replacing both the sugar and
the phosphate with a synthetic polymer, e.g., poly(N-vinyl),
poly(methacryloxyethyl), poly(methacrylamide), and
poly(etheylenimine). In some embodiments of the invention, at least
one of the internucleoside linkages is one of these structures. In
other embodiments of the invention, none of the internucleoside
linkages are one of these structures.
Intranucleoside Modifications
It is also possible to replace the ribose (RNA) or 2-doxyribose
(DNA) sugar with another moiety which is at least trifunctional (it
must bind the nucleobase, and two phosphate groups or replacements
thereof). The moiety may be another carbohydrate (sugar), or an
unrelated moiety.
If the moiety is a carbohydrate, it is preferably a monosaccharide.
Monosaccharides are polyhydroxy aldehydes (H[CHOH].sub.n--CHO) or
polyhydroxy ketones (H--[CHOH].sub.n--CO--[CHOH].sub.m--H) with
three or more carbon atoms, or derivatives thereof such as those
discussed below. It is preferably a triose, tetrose, pentose,
hexose, heptose or octose, or derivative thereof, with pentoses (5
carbons) or hexoses (6 carbons), and their derivatives, being more
preferred. Ribose is a pentose.
Each monosaccharide unit may be an aldose (having an aldehydic
carbonyl or potential aldehydic carbonyl group) or a ketose (having
a ketonic carbonyl or potential ketonic carbonyl group). If it is a
ketose, the position of the ketonic carbonyl (or potential ketonic
carbonyl, for a ketose derivative) may vary.
The monosaccharide unit further may have more than one carbonyl (or
potential carbonyl) group, and hence may be a dialdose, diketose,
or aldoketose. The term "potential aldehydic carbonyl group" refers
to the hemiacetal group arising from ring closure, and the ketonic
counterpart (the hemiketal structure).
In some preferred embodiments, the monosaccharide unit is a cyclic
hemiacetal (cyclized aldose) or hemiketal (cyclized ketose). Cyclic
forms with a three membered ring are oxiroses; with four, oxetoses,
with five, furanoses; with six, pyranoses; with seven, septanoses,
with eight, octanoses, and so forth. The locants of the positions
of ring closure may vary.
The monosaccharide may be linear or cyclic, with cyclic being
preferred. Cyclic forms with 3-8 ring atoms are preferred;
furanoses and pyranoses are especially preferred. Ribose is a
pyranose (one ring atom is oxygen).
The monosaccharide unit may further be, without limitation, a deoxy
sugar (alcoholic hydroxy group replaced by hydrogen), amino sugar
(alcoholic hydroxy group replaced by amino group), a thiosugar
(alcoholic hydroxy group replaced by thiol, or C.dbd.O replaced by
C.dbd.S, or a ring oxygen of cyclic form replaced by sulfur), a
seleno sugar, a telluro sugar, a C-substituted monosaccharide, an
unsaturated monosaccharide, an aza sugar (ring carbon replaced by
nitrogen), an amino sugar (ring oxygen replaced by nitrogen) an
alditol (carbonyl group replaced with CHOH group), aldonic acid
(aldehydic group replaced by carboxy group), a ketoaldonic acid, a
uronic acid, an aldaric acid, and so forth.
Carbohydrate derivatives of particular interest include alditols,
preferably of 3-8 carbon atoms, especially ribitol and glycerol.
Ribitol is the five carbon alditol corresponding to ribose.
Glycerol has three carbons. The nucleobase may be attached,
directly or indirectly, to any of the carbons not involved in the
intersugar linkages.
RNA analogues of particular interest include those in which the
ribonucleotides are 2' modified, e.g., 2' O-methyl derivatives.
When the nucleoside contains sugar, the internucleoside linkages
may, but need not, be 3' to 5' linkages as in DNA or RNA. For
example, linkages could be alternately 5' to 5' and 3' to 3'. Or
they could involve carbons other than the 3' and 5' carbons.
The sugar may also be replaced by a non-carbohydrate moiety, or
eliminated without replacement.
For a review of some of the more interesting structures, see
Leumann, "DNA Analogues: From Supramolecular Principles to
Biological Properties," Bioorganic & Medicinal Chem., 10:
841-54 (2002). The structures listed include 4'-6' linked
hexopyranosyl-NAs, 2'-4' linked pentopyranosyl-NAs, 3'-4' linked
pentopyranosyl-NAs, hexitol-NAs, locked nucleic acids (e.g.,
beta-D-Ribo-LNA), and bicyclo- and tricyclo-DNAs.
Peptide Nucleic Acid Oligomers
A category of alternative backbones of particular interest are
those in which the internucleoside linkage comprises a peptide
(--NHCO--) bond, as in a PNA oligomer (see FIG. 5, and FIG. 7
compound 7). A PNA oligomer is here defined as a series of
contiguous nucleotides wherein the internucleoside linkages
comprise peptide (--NHCO--) bonds.
The classic PNA oligomer is composed of (2-aminoethyl)glycine
units, with nucleobases attached by methylene carbonyl linkers.
That is, it has the structure
H--(--HN--CH.sub.2--CH.sub.2--N(--CO--CH.sub.2--B)--CH.sub.2--C-
O--).sub.n--OH where the parenthesized substructure is the PNA
monomer.
In the PNA oligomer, the nucleobase B is separated from the
backbone N by three bonds, and the points of attachment of the side
chains are separated by six bonds. The bases A, G, T, C and U are
preferred.
A PNA oligomer may further comprise one or more amino acid
residues, especially glycine and proline.
One can readily envision related molecules in which (1) the
--COCH2- linker is replaced by another linker, especially one
composed of two small divalent linker elements as defined below,
(2) a side chain is attached to one of the three main chain carbons
not participating in the peptide bond (either instead or in
addition to the side chain attached to the N of the classic PNA);
and/or (3) the peptide bonds are replaced by pseudopeptide
bonds.
A peptide bond has two small divalent linker elements, --NH-- and
--CO--. Thus, a preferred class of psuedopeptide bonds are those
which consist of two small divalent linker elements. Each may be
chosen independently from the group consisting of amine (--NH--),
substituted amine (--NR--), carbonyl (--CO--), thiocarbonyl
(--CS--), methylene (--CH.sub.2--), monosubstituted methylene
(--CHR--), disubstituted methylene (--CR1R2-), ether (--O--) and
thioether (--S--). The more preferred pseudopeptide bonds include:
N-modified --NRCO-- Carba .PSI. --CH.sub.2--CH.sub.2-- Depsi .PSI.
--CO--O-- Hydroxyethylene .PSI. --CHOH--CH.sub.2-- Ketomethylene
.PSI. --CO--CH.sub.2-- Methylene-Oxy --CH.sub.2--O-- Reduced
--CH.sub.2--NH-- Thiomethylene --CH.sub.2--S-- Thiopeptide
--CS--NH-- Retro-Inverso --CO--NH-- A single molecule may include
more than one kind of pseudopeptide bond.
Uhlmann, et al., "PNA: Synthetic Polyamide Nucleic Acids with
Unusual Binding Properties," Angew. Chem. Int. Ed. 37:2796-2823
(1998) describe several PNA analogues. These include phosphonic
ester nucleic acids (with N-(2-hydroxyethyl)aminomethyl phosphonic
acid backbones), PNA analogues with backbones bacsed on ornithine,
proline, diaminocyclohexane, and the phosphoramidate of
2-aminopropanediol, and PNA analogues in which the central amide
bond is replaced by a configurationally defined C.dbd.C double
bond. See monomers A-O in his FIGS. 11 and 12.
It may be particularly advantageous to use, at least in part, a PNA
oligomer backbone, when the oligonucleotide is to be engineered to
further include a peptide epitope.
Glycerol Nucleic Acid Oligomers
Polyol-derived nucleic acid oligomers are also of interest. The
polyol replaces the sugar of a conventional oligonucleotide.
Glycerol itself is 1,2,3-propanetriol. However, other polyols may
also be of interest. If the polyol has more than three carbons, the
interbase spacing will increase. Polyols with 3-6 carbons are
preferred. We will use the term "GNA oligomers" to encompass use of
the higher polyols, too.
Leumann notes that the 3' methyl analogue (1',2'-Seco DNA) of the
glycerol-DNA has been made. Neither readily form duplexes.
In 1978 Zamecnik and Stephenson (Zamecnik & Stephenson, 1978)
first proposed the use of synthetic oligo-nucleotides for
therapeutic purpose. The major problems associated with this
principle are the instability of the oligo-nucleotides towards
extra- and intracellular enzymes and the difficulty in penetrating
through the cell membrane (Uhlmann & Peyman, 1990). For that
reason, alternative chemically modified oligo-nucleotides have been
prepared as anti-sense oligo-nucleotides to achieve higher
stability towards various enzymes and higher ability to penetrate
cell membranes. In the same way, GNA is expected to be more stable
towards nucleases, and through lipophilic modification GNA is
likely to penetrate the cell membrane with more ease.
In some embodiments, the normal phosphate internucleoside linkage
is retained. As can be seen in FIG. 6, the glycerol linking agent
becomes a trifunctional linker of the form
--CH.sub.2--CH.sub.2(--O--)CH.sub.2--, with the C-2 carbon being
linked through the --O-- to a nucleobase. See also FIG. 7, compound
6.
In other embodiments, the normal phosphate linkage is replaced by
one of the form
-phosphate-linker Z-phosphate.
In these embodiments, linker Z is preferably aliphatic, more
preferably of the form -[(small alkyl)-O--].sub.n, where "small
alkyl" is not more than six carbons, and n is 1 to 20. Still more
preferably, the small alkyl is --CH.sub.2CH.sub.2--, and/or n=6, as
shown in FIG. 3, and in FIG. 7 compound 2. Segmented
Oligonucleotides
Segments are demarcated by the presence of long internucleoside
linkages, as defined below.
A short internucleoside linkage is a linkage having a main chain of
not more than five atoms (in DNA and RNA, the normal linkage is a
phosphate group, having a main chain of three atoms, O--P--O). By
this definition, the normal PNA internucleoside linkage,
--C(.dbd.O)--NH--CH.sub.2--, is a short linkage as its main chain
has a length of only three atoms (C--N--C).
A long internucleoside linkage is any linkage between nucleosides
that does not qualify as a short linkage. Thus, the linkages shown
in FIG. 3 are long linkages. As shown in FIG. 3, the long
internucleoside linkage may include at least one lipophilic
group.
A segment of the oligonucleotide is defined as (1) a consecutive
series of two or more nucleosides within which adjacent pairs are
connected by short internucleoside linkages, or (2) a single
nucleoside whose only connection to other nucleosides is by long
internucleoside linkage(s).
Thus, in FIG. 3, we see two segment oligonucleotides of the form
CpG-long linkage-CpG, where each CpG is considered a segment. A
structure of the form CxG-long linkage-CxG, where the "x" was a
short linkage, would also be a two segment oligonucleotide. A
structure of the form GpApCpGpTpT-long linkage-GpApCpGpTpT, ii.e.,
one in which the hexanucleotide of compound 1 (FIG. 7) replaced
each CpG of the FIG. 3 compounds, would likewise be a two segment
oligonucleotide. GxAxCxGxTxT-long linkage-GxAxCxGxTxT, wherein the
"x"'s are all short linkages (and may be the same or different),
would be a two segment oligonucleotide.
In many biological systems, the effect of a ligand is enhanced if
it is presented in multiple copies as part of a single molecule.
For example, immunogens have been constructed in the form of linear
molecules with clustered epitopes, see WO98/46246, or of branched
molecules presenting several epitopes (e.g., the MAP-4, where four
epitopes are attached to a branched lysine core).
In a preferred embodiment, the oligonucleotide comprises at least
two segments, and at least two of the segments each comprise at
least one CxG dinucleotide unit. Desirably, all of the segments
each comprise at least one CxG dinucleotide unit.
Preferably, at least one pair of CxG-containing segments are
connected, directly or indirectly, by a long internucleoside
linkage. Thus, we have, in the simplest case, (CxG containing
segment)-long linkage-(CxG containing segment). We could also have,
e.g., (CxG containing segment)-long linkage-(other segment)-long
linkage-(CxG containing segment).
The multisegmented oligonucleotide of the present invention may
have more than two segments. In this case, it can be linear, i.e.,
segment (-long linkage-segment).sub.n, where n is at least two and
preferably is not more than 20, more preferably not more than ten,
still more preferably not more than five. The linear structure may
be acyclic or cyclic. In the latter case, we have, e.g.,
##STR00005## The cyclic multisegmented oligonucleotide may comprise
more than two segments, with suitable linkages. Of course, even a
single segment oligonucleotide of the present invention can be
cyclic, e.g.,
##STR00006##
An advantage of a cyclic molecule is that it can form a stable
three dimensional structure, which can enhance receptor binding
affinity and specificity.
Alternatively, it may be branched, e.g., three segments each linked
to a trivalent core element serving as the long internucleoside
linkage for each of the three pairs of segments. Or four segments
may be linked to a tetravalent core element. More complex branching
structures are also possible, with a plurality of branching
points.
A branched long linkage of particular interest is one comprising a
pentaerythritol (PET) structure; such structures are discussed in
Jiang et al., U.S. Provisional Appl. No. 60/378,645, filed May 9,
2002, incorporated by reference in its entirety.
The long linkages can, independently, be flexible or rigid. The
length of the long linkage can be controlled so that the spacing of
the CxG dinucleotide units substantially matches the spacing of
receptor binding moieties.
Within a segment, if all of the international internucleoside
linkages are chemically identical, we have a simple segment. If the
linkages vary, we have a hybrid segment. GpApCpGpTpT would be a
simple segment. GpApC x GpTpT, where the x denotes a short linkage
other than phosphate (p), would be a hybrid segment. Any of the
segments may be simple segments or hybrid segments.
Free Ends; 5' and 3' Ends
When, in this disclosure, it is stated that a lipophilic group is
attached to a free end, or more particularly to the 5' or 3' end,
it will be understood that this group is covalently incorporated
into the end, that is, that it is at least a part of the end.
A linear oligonucleotide will have two free ends. In DNA and RNA,
these free ends are identified as the 5' and 3' ends. In DNA and
RNA, the nucleotides may be said to be connected by 5' to 3'
phosphodiester linkages (C--O--P(.dbd.O)--O--C), which employ said
phosphate groups. More particularly, the 5' carbon of the sugar of
one nucleotide is bonded to an oxygen of its phosphate group.
Another oxygen of the same phosphate group is in turn bonded to the
3' carbon of the sugar of the previous nucleotide.
It follows that the first nucleotide of DNA or RNA has a free
phosphate group attached to the 5' carbon. Likewise, because of the
chemistry of the corresponding mononucleotide, the last nucleotide
has a free hydroxyl group attached to its 3' carbon. Hence, DNA and
RNA normally have a 5' phosphate and 3' hydroxyl ends.
In the molecular biology art, it is known that one may modify the
5' and/or 3' ends of DNA or RNA. The most common modification is
the conversion of the 3' hydroxyl to a 3' phosphate. Likewise, the
5' phosphate can be converted to a 5' hydroxyl.
The terms 5' and 3' ends are readily applied, not only to DNA or
RNA, but also to an analogue which retains the sugar unit of DNA or
RNA and merely changes the internucleoside linkage without changing
the points of attachment (the 5' and 3' carbons) on the sugar
units. These terms may also be used for oligonucleotides with
hybrid backbones, as long as the lipophilic group is attached to a
DNA or RNA mononucleotide (see FIG. 6; attachment to 3' end).
Reference to the 5' end of an oligonucleotide shall, if the
oligonucleotide does not in fact have a true 5' or 3' end because
of its use of an alternative backbone, be defined as the end
closest to the 5' end of the internal DNA or RNA sequence, if any.
If there is no DNA or RNA sequence whatsoever, the 5' end shall be
deemed to mean the end of the oligonucleotide which is closest to
the cytosine (C) of at least one CxG dinucleotide unit. The 3' end
will be analogously defined by reference to the 3' end of the
internal DNA or RNA or, if need be, by reference to the location of
the guanine of the CxG dinucleotide unit.
In a cyclic oligonucleotide, there are no free ends. However,
lipophilic groups may be incorporated into the internucleoside
linkages.
In a branched oligonucleotide, the branches have one free end, and
one end that is attached, directly or indirectly, to the remainder
of the oligonucleotide.
Lipophilic and Strongly Lipophilic Groups
Oligonucleotides, in general, are strongly hydrophilic (and
lipophobic) by virtue of their phosphate groups. The standard
nitrogenous bases adenine, guanine, cytosine, thymine and uracil
are also hydrophilic.
The lipophilicity of the oligonucleotides of the present invention
is increased by covalently incorporating into them one or more
lipophilic groups, which more preferably are strongly lipophilic or
highly lipophilic as defined below.
These lipophilic groups may be incorporated at one or more of the
following sites:
as at least part of one or both of the free ends of the molecule
(see FIG. 2 for 3' modification and FIG. 4 for 5'
modification);
as at least part of a substituent of a nucleoside; or
as at least part of an internucleoside linkage (see FIG. 3).
The oligonucleotide is deemed to comprise a lipophilic group if any
moiety consisting of at least 5 atoms other than hydrogen qualifies
as a lipophilic group by the criteria set forth below. Thus, the
lipophilic group may be, e.g., a side chain on a terminal moiety or
on the internucleoside linkage, as opposed to the entire terminal
moiety or internucleoside linkage.
The incorporation may be direct or indirect, e.g., the lipophilic
group may be attached to the 5' or 3' end through a phosphate group
or an --O-- linkage (the residue of a hydroxyl group), or some
other linker.
When the 5' or 3' end of the oligonucleotide comprises a lipophilic
group, preferably the entire 5' or 3' end, exclusive of any
phosphate group, or of any analogue of a phosphate group in which
one or more oxygens are replaced by sulfur, selenium or tellurium
atoms, is lipophilic. Thus, in FIG. 7, compound 1, the lipophilic
group has SMILES notation CC(O)CCCCCCCCCC.
FIG. 3 show lipophilic groups attached to a CpG dinucleotide with a
standard sugar-phosphate backbone. The 3' ends are modified to have
a phosphate group which in turn is connected to the lipophilic
group through one of the oxygens. FIG. 4 shows an oligonucleotide
wherein the lipophilic group is attached to the 5' phosphate
end.
The lipophilic moieties may be aliphatic or aromatic, and linear or
branched. Some of the preferred lipophilic moieties are depicted in
FIG. 2, and may be characterized as follows:
linear aliphatic, 14 carbons
as above, but hydroxylated at C-2
branched aliphatic, one branch is 14 carbons, branching is at C-2
and goes through --O-- to another 14 carbon chain.
branched aliphatic of form CH.sub.2--C(CH.sub.2OH) (CH.sub.2--O-14
carbon alkyl).sub.2
linear aliphatic of form (CH.sub.2CH.sub.2O).sub.6-14 carbon
alkyl
mixed aliphatic-fused aromatic (see FIG. 2).
See also FIG. 7, depicting the following preferred lipophilic
groups: 1) --CH2(OH)-10 carbon alkyl 2)
--PO4-(CH2CH2O)6-PO4-CH2OH-10 carbon alkyl 3) to 5)
--PO4-CH.sub.2OH-10 carbon alkyl 6) as above but 14 carbon alkyl 7)
--CH2-O-14 carbon alkyl
The lipophilicity of a group may be determined by measuring the
partition coefficient of the molecule HZ (where Z is the group in
question) between a nonpolar solvent (e.g., ethanol, dioxane,
acetone, benzene, n-octanol) and water, at STP. The lipophilicity
may be defined as the logarithm of this partition coefficient; it
will then be positive for molecules which prefer the nonpolar
solvent. Thus, a lipophilic group is one for which logP is greater
than zero.
The partition coefficient (P) is defined as the ratio of the
equilibrium concentrations of a dissolved substance in a two-phase
system consisting of two largely immiscible solvents. One such
system is n-octanol:water; the octanol phase will contain about 20%
water and the water phase about 0.008% octanol. Thus, the relevant
partition coefficient (Pow) is the ratio of the molar concentration
of the solute in octanol (O) saturated with water (w) to its molar
concentration in water saturated with octanol. N-octanol is a
useful surrogate for biological membranes because it, like many
membrane components, is amphiphilic. (Reference hereafter to log P
shall mean log Pow, unless otherwise stated.)
At least one lipophilic group is preferably a strongly lipophilic
group. For the purpose of this disclosure, a strongly lipophilic
group is defined as being one for which the lipophilicity
calculated as the log of the n-octanol:water partition coefficient,
by any of the three art-recognized methods set forth below as
(A)-(C) is greater than that calculated for any of the side chains
of the genetically encoded amino acids (hereafter, the reference
side chains). The genetically encoded amino acids with lipophilic
side chains are the aliphatic amino acids alanine, valine, leucine,
isoleucine, and methionine, and the aromatic amino acids
tryptophan, tyrosine and phenylalanine. (The rationale for using
the lipophilic genetically encoded amino acids as a standard for
"strongly lipophilic" is that they are part of PNAs.)
In one embodiment, the side chain in question is more lipophilic
than any of the reference side chains when its lipophilicity, and
that of the reference side chains, is determined according to
method (A) below.
In a second embodiment, the side chain in question is more
lipophilic than any of the reference side chains when its
lipophilicity, and that of the reference side chains, is determined
according to method (B) below.
In a third embodiment, the side chain in question is more
lipophilic than any of the reference side chains when its
lipophilicity, and that of the reference side chains, is determined
according to method (C) below.
In a fourth embodiment, the side chain in question is more
lipophilic than any of the reference side chains when its
lipophilicity, and that of the reference side chains, are
determined in accordance with a preferred method of determining the
partition coefficient, which method is chosen on the basis of the
predicted log Pow value (this predicted value is itself determined
by method (C) below: (A) for predicted log Pow values of 0 to 4,
the shake flask method set forth in EPA Product Properties Test
Guidelines OPPTS 830.7550 EPA 712-c-96-038 (August 1996)(Note that
negative log Pow values imply that the compound is not lipophilic
at all.) (B) for predicted log Pow values of 4 to 6, the liquid
chromatography estimation method set forth in the EPA Product
Properties Test Guidelines OPP13 830.7570, EPA 712-C-96-040 (August
1996). (This method may be used for estimating Pow values of 0 to
6.) (C) for predicted log Pow values higher than 6, the predictive
method described in Meylan, et al., Atom/fragment contribution
method for estimating octanol-water partition coefficients", J.
Pharm. Sci., 84: 83-92 (1995). (note that if predicted log Pow
values are higher than 6, so experimental determination is
necessary).
In Meylan's method, the predicted log Pow is obtained by adding
weighted coefficients for each fragment (the raw coefficient
multiplied by the number of copies of that fragment) to the
constant 0.2290. The fragments considered include --CH3 (0.5473),
--CH2-- (0.4911), --CH (0.3614), --OH (-1.4086), --NH2 (-1.4148),
--C(.dbd.O)N (-0.5236), --SH (-0.0001), --NH-- (-1.4962), --N.dbd.C
(-0.0010), --O-- (-1.2566), ALDEHYDE-cho (-0.9422), -tert C so 3+C
attached (0.2676), C no H not tert (0.9723), aromatic C (0.2940),
aromatic N (5 membered ring) (-0.5262), and aromatically attached
--OH (-0.4802); all aliphatic or aliphatically attached unless
otherwise stated.
For more information on methods of determining Pow, see Sangster,
J., Octanol-Water Partition Coefficients: Fundamentals and Physical
Chemistry (April 1997) (ISBN 0-471-9739).
For tabulations of octanol-water partition coefficients, see the
EPA "Chemicals in the Environment: OPPT Chemicals Fact Sheets" the
USDA Pesticide Properties Database, Sangster, J., "Octanol-Water
Partition Coefficients of Simple Organic Compounds", J. Phys. Chem.
Ref. Data, 18:1111-1230 (1989); Verbruggen, E. M. J., et al.,
"Physiochemical Properties of Higher Nonaromatic Hydrocarbons:
Literature Study," J. Phys. Chem. Ref. Data, 29:1435-46 (2000). For
more sources, see references cited at Penn State University
Libraries, Physical Sciences Library, octanol-water Partition
Coefficients (last updated Aug. 21, 2001), at the URL
libraries.psu.edu/crsweb/physci/coefficients.htm. It should be
noted that the Pow values compiled for different compounds may have
been determined by different methodologies.
The Meylan algorithm is implemented in the program LogPow (KowWin).
An online version of the program, available at
esc.syrres.com/interkow/kowdemo.htm, accepts either CAS registry
numbers or SMILES structure notations. The program also reports
experimentally determined values, if in its database.
A group is expected to be a lipophilic group if its logP, as
predicted by the Meylan algorithm, is greater than zero.
Preferably, the logP predicted by the Meylan algorithm is at least
1, at least 2, at least 3, at least 4, at least 4, at least 6, at
least 7, at least 8, at least 9, or at least 10, the higher the
more preferred.
At least one lipophilic group is preferably a "highly lipophilic
(Meylan) group". For the purpose of this disclosure, a "highly
lipophilic (Meylan) group" is defined as one for which the
lipophilicity calculated by the Meylan algorithm is at least 2.7.
The highest logP predicted by the Meylan algorithm for the side
chains of the genetically encoded amino acids is 2.60 (Trp); the
highest experimentally determined logP for the same side chains is
2.89 (Ile). It should be noted that most "strongly lipophilic
groups" will also be "highly lipophilic (Meylan) groups," and vice
versa.
Preferably, the lipophilic group will comprise not more than 100
atoms other than hydrogen, more preferably, not more than 80 such
atoms, still more preferably, not more than 60 such atoms, even
more preferably not more than 40 such atoms.
Preferably, the lipophilic group will comprise at least five atoms
other than hydrogen (leucine has four such atoms), more preferably
at least 11 such atoms (tryptophan has 10), still more preferably
at least 13 such atoms, even more preferably at least 21 such
atoms.
Preferably, the side chain has an elemental composition limited to
the elements carbon, silicon, hydrogen, oxygen, nitrogen, sulfur,
and phosphorous. Preferably, the majority of the bonds within the
side chain which do not involve hydrogen are carbon-carbon
bonds.
Preferably, the side chain is of the general form --Y-Z where --Y--
is a spacer, and -Z is one or more aliphatic, and/or one or more
aromatic moieties. The spacer is preferably selected from the group
consisting of --O--, --S--, --NH--, --NR--, --PO4-, --C(.dbd.O)--
and --C(.dbd.S)--. Z is preferably aliphatic. Alternatively, the
spacer may be Y', where Y' is -alkyl-Y, and alkyl is a small alkyl
of 1-4 carbon atoms. Other spacers, and other general forms, are
permitted.
The aliphatic moieties, such as those of -Z, may, independently,
comprise one or more spacers, which preferably are selected from
the group defined above.
The lipophilic side chain may be entirely an aliphatic moiety or
moieties, entirely an aromatic moiety or moieties, or a combination
of at least one aliphatic moiety and at least one aromatic
moiety.
Each aliphatic moiety may, independently, be linear, cyclic, a
combination of linear and cyclic, branched but acyclic, or branched
but with one or more branches comprising a cyclic moiety. It also
may be saturated or unsaturated. If saturated, there may be one or
more double and/or one or more triple bonds.
In one preferred embodiment, the side chain is a linear side chain
which is an ether, i.e., --(CH2)i-O--(CH2)j, where "i" is 0 or 1
and j is 6 to 26. In compound 1a, "i" is 0 and "j" is 14.
In another preferred embodiment, the side chain is a two-branched
aliphatic moiety, of the general structure --Y1Y2(Z1,Z2), where Y1
is null (i.e., the main chain carbon is directly bonded to Y2), or
a spacer as defined above, Y2 is a small branched alkyl group
connecting Y1 (or if Y1 is null, the main chain carbon) to Z1 and
Z2, Z1 is --O(CH2)mCH3, and Z2 is --O(CH2)nCH3, where m and n are
independently chosen integers in the range of 6-26. Preferably, Y1
is --C(.dbd.O)-- or --NH--, and Y2 is --CH(CH2-)CH2-.
In another preferred embodiment, the side chain is a three branched
aliphatic moiety, of the general structure --Y1Y2(Z1, Z2, Z3),
where Y1 is null (i.e., the main chain carbon is directly bonded to
Y2), or a spacer as defined above, Y2 is a small branched alkyl
group connecting Y1 (or if Y1 is null, the main chain carbon) to
Z1, Z2 and Z3, Z1 is --O(CH2)mCH3, Z2 is --O(CH2)nCH3, Z3 is
--O(CH2)kCH3, and m, n and k are independently chosen from the
range of 6-26. Y2 is preferably --C(CH2-)(CH2-)CH2-.
In another preferred embodiment, the side chain comprises one or
more fatty acid moieties. Thus, the side chain may be of the form
--Y1Y2(Z1 . . . Zi), where i is 1 to 2, Y1 is a previously defined,
Y2 is null or is an alkyl group connecting the Y2 to the 1-3 Z
groups, and at least one Z group is a fatty acid group of the form
--O--CO-Q, where Q is primarily alkyl but may include alkenyl,
alkynyl, or ether linkages. The fatty acids are carboxylic acids,
often derived from or contained in an animal or vegetable fat or
oil. All fatty acids are composed of a chain of hydrocarbon groups
containing from 4 to 22 carbon atoms and characterized by a
terminal carboxyl radical. They may be designated by "the number of
carbon atoms: number of double bonds", and optionally the locations
of cis/trans isomerism. Thus, suitable fatty acids include those
with designations 4:0, 6:0, 8:0, 10:0, 12:0, 14:0, 16:0, 16:1 (9c),
18:0, 18:1 (9c), 18:2 (9c, 12c), 18:3 (9c, 12c, 15c), 18:4 (6c, 9c,
12c, 15c), 18:3 (9c, 11t, 13t), 18:1 (9c) 12-OH, 20:1 (9c), 20:1
(11c), 20:4 (8c, 11c, 14c, 17c), 20:5 (5c, 8c, 11c, 14c, 17c),
22:0, 22:1 (11c), 22:1 (13c), 22:5 (7c, 10c, 13c, 16c, 19c) and
22:6 (4c, 7c, 10c, 13c, 16c, 19c), all of which are found in
naturally occurring glycosides.
If the side chain comprises a plurality of cyclic moieties, they
may be fused (forming a polycyclic moiety) or unfused, and may have
the same or a different number of sides. Typically, they will each
have 3-6 sides. One or more of the sides may be a double or triple
bond. The cyclic moieties may be heterocyclic in character. In one
preferred embodiment, the side chain comprises a steroid moiety.
This is a polycyclic moiety with four fused rings, one five-sided
and three six-sided.
The aliphatic moieties may comprise one or more phosphoryl groups,
and, if they do so, the number of such groups in the side chain is
preferably not more than two. Phosphoryl groups are found in the
lipids of bacterial membranes, e.g., the lipid monophosphoryl lipid
A (MPLA).
The aromatic moieties may comprise one or more rings. If there is
more than one ring, the rings may be fused or unfused.
Using the program LogKow, we have calculated (see below) logP
values for several preferred groups (Table K-1), and for some
reference compounds (Table K-2). Compounds in Table K-2 are not
necessarily inappropriate. Where LogKow also provided an
experimental database value, this is also given below. The greyed
rows in Table K-2 are for hydrophilic compounds.
TABLE-US-00003 TABLE K-1 Predicted and Experimental LogP Values of
Certain Preferred Lipophilic Groups SMILES (lower case LogP is
arom) or CAS Reg. # Comments Pred Exp COCCCCC CCCCC --C--O-- linked
15C 6.45 ? .sup. CCCCC arm MW 228.42 COCCCCC CCCCC --C--O-- linked
17C 7.43 ? .sup. CCCCC CC arm COCCCCC CCCCC --C--O-- linked 13C
5.47 ? .sup. CCC arm CO CCCCC CC --C--O-- linked 7C 3.01 ? arm CO
CCCCC CCCCC --C--O-- linked 27C 12.84 ? .sup. CCCCC CCCCC arm .sup.
CCCCC CC MW 410.77 CCO CCCCC CCCCC --CCO-linked 15C 7.43 ? .sup.
CCCCC arm O.dbd.CC (COCCCCCCC) COCCCCCCC ##STR00007## 5.11 ? -- MW
524.92 ##STR00008## 12.96 ? -- MW 861.57 ##STR00009## 24.75 ? NC
(COCCCCCCC) COCCCCCCC ##STR00010## 5.23 ? -- ##STR00011## 13.09 ?
-- MW 848.57 ##STR00012## 24.88 ? C (COCCCCCCC) COCCCCCCC
##STR00013## 6.18 ? -- ##STR00014## 14.03 ? -- MW 833.56
##STR00015## 25.82 ? -- triether m = n = k = 6 8.78 ? CC (O)
Compounds 1, 3, 4.7 ? CCCCC CCCCC 4 and 5, FIG. 7, 3' end
CCOCCOCCOCCOCCOCC Compound 2, FIG. 2.33 ? OP(.dbd.O) (O)O CC(O) 7,
3' end CCCCC CCCCC CCCCC CCCCC CCCC Compounds 1 and 7.22 7.20 6,
FIG. 7, 3' end CC(O) R of 2.sup.nd compound 5.68 CCCCC CCCCC in
FIG. 2 CC CC R of 3.sup.rd compound 12.76 (OCCCCCCCCCCCCCC) in FIG.
2 CCCCCCCCCCCC CC(CO) R of 4.sup.th compound 12.46
(COCCCCCCCCCCCCCC) in FIG. 2 COCCCCCCCCCCCCCC CCOCCOCCOCCOCCOCC R
of 5.sup.th compound 5.57 O in FIG. 2 CCCCC CCCCC CCCC
CCCNC(.dbd.O) R of 6.sup.th compound 10.31 OC(CCC(C1.dbd.CCC2C(C in
FIG. 2 (C(C3)C(CCCC(C)C) (cholesterol- C) (CC4)C)C3) (C24) related,
note C)C1 boldfaced SMILES)
TABLE-US-00004 TABLE K-2 Predicted and Experimental LogP Values for
Certain Reference Compounds SMILES (lower case is arom) or LogP
Compound CAS Reg. # Comments Pred Exp ##STR00016## ##STR00017##
##STR00018## ##STR00019## ##STR00020## ##STR00021## ##STR00022##
##STR00023## ##STR00024## ##STR00025## ##STR00026## ##STR00027##
##STR00028## ##STR00029## ##STR00030## ##STR00031## ##STR00032##
##STR00033## ##STR00034## ##STR00035## ##STR00036## ##STR00037##
##STR00038## ##STR00039## ##STR00040## ##STR00041## ##STR00042##
##STR00043## ##STR00044## ##STR00045## ##STR00046## ##STR00047##
##STR00048## ##STR00049## ##STR00050## ##STR00051## ##STR00052##
##STR00053## ##STR00054## ##STR00055## ##STR00056## ##STR00057##
##STR00058## ##STR00059## ##STR00060## ##STR00061## ##STR00062##
##STR00063## ##STR00064## ##STR00065## ##STR00066## ##STR00067##
##STR00068## ##STR00069## ##STR00070## ##STR00071## ##STR00072##
##STR00073## ##STR00074## ##STR00075## psoralen 66-97-7 2.06 1.67
acridine 260-94-6 3.32 3.40 biotin 58-85-5 0.39 cholesterol 57-88-5
8.74 methane C Ala side c 0.78 1.09 Propane C(C)C Val side c 1.81
2.36 Ethane, CCSC Met side c 1.41 1.54 (methylthio)- n-butane CCCC
Ile side 2.31 2.89 chain 2-methyl CC(C)C Leu side c 2.23 2.76
propane toluene Cclcccccl Phe side c 2.54 2.73 p-cresol
Cclccc(O)ccl Tyr side c 2.06 1.94 3-methyl Cclcnc2ccccc Trp side c
2.60 2.60 indole 12 methyl CO CCCC 1.54 1.66 n-butyl ether
n-pentane CCCCC one more c 2.80 3.39 than Leu OP(.dbd.O)(O)O
Compounds 3.15 ? CC(O) 1, FIG. 7, CCCCC CCCCC 3' end incl.
Phosphate OP(.dbd.O)(O)O Compound 0.78 ? CCOCCOCCOCCO 2, FIG. 7,
CCOCC 3' end OP(.dbd.O)(O)O incl. both CC(O) phosphates CCCCC CCCCC
OP(.dbd.O)(O)O Compound 5.67 ? CCCCC CCCCC 6, FIG. 7, CCCC 3' end,
including phosphate
Targeting Moieties
The oligonucleotides of the present invention may additionally
comprise one or more cell-type specific targeting moieties to
improve delivery to a particular cell type. For example, they may
comprise a carbohydrate or peptide moiety which is specifically
recognized by a cell surface receptor. Useful carbohydrate moieties
include galactose, N-acetylgalactosamine (GalNAc), fucose, mannose,
and sialic acid (N-acetyl neuraminic acid).
Other Immunomodulatory Moieties
The oligonucleotides of the present invention may further comprise
one or more immunomodulatory moieties other than the CxG
dinucleotide unit.
For example, they may comprise a thymidine dimer, as previously
noted. They may also comprise lipoteichoic acid or a derivative
thereof. LTA is a membrane component of gram positive bacteria and
can activate the innate immune response. One possible derivative is
one in which the ester linkage between D-Alanine and the secondary
hydroxyl group of the glycerol moiety is replaced by an amide bond,
which will increase resistance to hydrolysis. The LTA-like moiety
may be attached to the 3' or 5' ends of the oligonucleotide, or
incorporated into one or more internucleoside linkages.
Immunogen
The immunogen of the present invention is a molecule comprising at
least one disease-associated B or T cell epitope, as defined below,
and which, when suitably administered to a subject (which, in some
cases, may mean associated with a liposome or with an
antigen-presenting cell), elicits a humoral and/or cellular immune
response which is protective against the disease.
The immunostimulatory oligonucleotide of the present invention may
be administered with the immunogen (in the same or a separate
composition), or before or after administration of the immunogen,
provided that the interval between the administration of the
oligonucleotide and the immunogen is not so long that the
oligonucleotide cannot potentiate the immune response to the
immunogen.
The most preferred immunogenic composition comprises the BLP25
liposomal vaccine formulation described in Koganty et al.,
Synthetic Glyco-Lipo-Peptides as Vaccines, U.S. Provisional Appl.
No. 60/377,595, filed May 6, 2002 (DOcket: Koganty4.1-USA), which
is hereby incorporated by reference in its entirety. This liposomal
formulation comprises a MUC1-derived 25-mer lipopeptide, also
described therein, which is the most preferred immunogen. The
composition may include a oligonucleotide as an adjuvant. It may
also include other adjuvants or other immunological agents (e.g.,
cytokines).
Epitope
The epitopes of the present invention may be B-cell or T-cell
epitopes, and they may be of any chemical nature, including without
limitation, peptides, carbohydrates, lipids, glycopeptides and
glycolipids. The epitope is at least substantially the same as a
naturally occurring epitope. It may be identical to a naturally
occurring epitope, or a modified form of a naturally occurring
epitope.
A term such as "MUC1 epitope", without further qualification, is
intended to encompass, not only a native epitope of MUC1, but also
a mutant epitope which is substantially identical to a native
epitope. Such a mutant epitope must be cross-reactive with a native
MUC1 epitope. Likewise, a term such as "tumor-associated epitope"
includes both native and mutant epitopes, but the mutant epitope
must be cross-reactive with a native tumor-associated epitope.
B-Cell Epitopes
B-cell epitopes are epitopes recognized by B-cells and by
antibodies.
B-cell peptide epitopes are typically at least five amino acids,
more often at least six amino acids, still more often at least
seven or eight amino acids in length, and may be continuous
("linear") or discontinuous ("conformational") (the latter being
formed by the folding of a protein to bring noncontiguous parts of
the primary amino acid sequence into physical proximity).
B-cell epitopes may also be carbohydrate epitopes.
T Cell Epitopes
The T cell epitope, if any, may be any T cell epitope which is at
least substantially the same as a T-cell epitope of an antigen
including a hapten) which is associated with a disease or adverse
condition to a degree such that it could be prophylactically or
therapeutically useful to stimulate or enhance a cellular immune
response to that epitope. Such diseases and conditions include, but
are not limited to parasitic diseases such as schistosomiasis and
leishmania, fungal infections such as candidiasis, bacterial
infections such as leprosy, viral infections such as HIV
infections, and cancers, especially solid tumors. Of course, the
greater the degree of specificity of the epitope for the associated
disease or adverse condition, the more likely it is that the
stimulation of an immune response to that epitope will be free of
adverse effects.
The epitope must, of course, be one amenable to recognition by
T-cell receptors so that a cellular immune response can occur. For
peptides, the T-cell epitopes may interact with class I or class II
MHC molecules. The class I epitopes usually 8 to 15, more often
9-11 amino acids in length. The class II epitopes are usually 5-24
(a 24 mer is the longest peptide which can fit in the Class II
groove), more often 8-24 amino acids. If the immunogen is larger
than these sizes, it will be processed by the immune system into
fragments of a size more suitable for interaction with MHC class I
or II molecules.
The carbohydrate T-cell epitopes may be as small as a single sugar
unit (e.g., Tn). They are preferably no larger than five
sugars.
Many T-cell epitopes are known. Several techniques of identifying
additional T-cell epitopes are recognized by the art. In general,
these involve preparing a molecule which potentially provides a
T-cell epitope and characterizing the immune response to that
molecule. Methods of characterizing the immune response are
discussed in a later section.
The reference to a CTL epitope as being "restricted" by a
particular allele of MHC Class I molecules, such as HLA-Al,
indicates that such epitope is bound and presented by the allelic
form in question. It does not mean that said epitope might not also
be bound and presented by a different allelic form of MHC, such as
HLA-A2, HLA-A3, HLA-B7, or HLA-B44.
Disease-Associated and Disease-Specific Epitopes
A disease is an adverse clinical condition caused by infection or
parasitization by a virus, unicellular organism, or multicellular
organism, or by the development or proliferation of cancer (tumor)
cells. (The cancers of interest include those set forth in
WO98/18810 and WO99/51259.)
The unicellular organism may be any unicellular pathogen or
parasite, including a bacteria, fungus or protozoan. (The viruses,
bacteria and fungi of interest include those set forth in
WO98/18810 and WO99/51259.) The multicellular organism may be any
pathogen or parasite, including a protozoan, worm, or arthropod.
Multicellular organisms include both endoparasites and
ectoparasites. Endoparasites are more likely to elicit an immune
response, but, to the extent they can elicit a protective immune
response, ectoparasites and their antigens are within the purview
of the present invention.
An epitope may be said to be directly associated with a viral
disease if it is presented by a virus particle, or if it is encoded
by the viral genome and expressed in an infected cell.
An epitope may be said to be directly associated with a disease
caused by a unicellular or multicellular organism if it presented
by an intracellular, surface, or secreted antigen of the causative
organism.
An epitope may be said to be directly associated with a particular
tumor if it is presented by an intracellular, surface or secreted
antigen of said tumor. It need not be presented by all cell lines
of the tumor type in question, or by all cells of a particular
tumor, or throughout the entire life of the tumor. It need not be
specific to the tumor in question. An epitope may be said to be
"tumor associated" in general if it is so associated with any tumor
(cancer, neoplasm).
Tumors may be of mesenchymal or epithelial origin. Cancers include
cancers of the colon, rectum, cervix, breast, lung, stomach,
uterus, skin, mouth, tung, lips, larynx, kidney, bladder, prostate,
brain, and blood cells.
An epitope may be indirectly associated with a disease if the
epitope is of an antigen which is specifically produced or
overproduced by infected cells of the subject, or which is
specifically produced or overproduced by other cells of the subject
in specific, but non-immunological, response to the disease, e.g.,
an angiogenic factor which is overexpressed by nearby cells as a
result of regulatory substances secreted by a tumor.
The term "disease associated epitope" also includes any
non-naturally occurring epitope which is sufficiently similar to an
epitope naturally associated with the disease in question so that
antibodies or T cells which recognize the natural disease epitope
also recognize the similar non-natural epitope. Similar comments
apply to epitopes associated with particular diseases or classes of
diseases.
An epitope may be said to be specific to a particular source (such
as a disease-causing organism, or, more particular, a tumor), if it
is associated more frequently with that source than with other
sources, to a detectable and clinically useful extent. Absolute
specificity is not required, provided that a useful prophylactic,
therapeutic or diagnostic effect is still obtained.
In the case of a "specific tumor-specific" epitope, the epitope is
more frequently associated with that tumor that with other tumors,
or with normal cells. Preferably, there should be a statistically
significant (p=0.05) difference between its frequency of occurrence
in association with the tumor in question, and its frequency of
occurrence in association with (a) normal cells of the type from
which the tumor is derived, and (b) at least one other type of
tumor. An epitope may be said to be "tumor-specific" in general is
it is associated more frequently with tumors (of any or all types)
than with normal cells. It need not be associated with all
tumors.
The term "tumor specific epitope" also includes any non-naturally
occurring epitope which is sufficiently similar to a naturally
occurring epitope specific to the tumor in question (or as
appropriate, specific to tumors in general) so that antibodies or T
cells stimulated by the similar epitope will be essentially as
specific as CTLs stimulated by the natural epitope.
In general, tumor-versus-normal specificity is more important than
tumor-versus-tumor specificity as (depending on the route of
administration and the particular normal tissue affected), higher
specificity generally leads to fewer adverse effects.
Tumor-versus-tumor specificity is more important in diagnostic as
opposed to therapeutic uses.
The term "specific" is not intended to connote absolute
specificity, merely a clinically useful difference in probability
of occurrence in association with a pathogen or tumor rather than
in a matched normal subject.
Parasite-Associated Epitopes
In one embodiment, the epitope is a parasite-associated epitope,
such as an epitope associated with leishmania, malaria,
trypanosomiasis, babesiosis, or schistosomiasis. Suitable
parasite-associated epitopes include, but are not limited to, the
following.
TABLE-US-00005 Parasite Epitope References Plasmodium Falciparum
(NANP)3 Good et al (1986) (Malaria (SEQ ID J. Exp. Med. 164: 655
NO:12) Circumsporoz. Good et al (1987 protein Science 235: 1059 AA
326-343 Leishmania donovani Repetitive Liew et al (1990) peptide J.
Exp. Med. 172: 1359 Leishmani major EAEEAARLQA Longenecker, (SEQ ID
NO: 4) et al., 08/229,606 Toxoplasma gondii P30 surface Darcy et al
(1992) protein J. Immunolog. 149: 3636 Schistosoma mansoni Sm-28GST
Wolowxzuk et al (1991) antigen J. Immunol 146: 1987
Virus-Associated Epitopes
In another embodiment, the epitope is a viral epitope, such as an
epitope associated with human immunodeficiency virus (HIV),
Epstein-Barr virus (EBV), or hepatitis. Suitable viral epitopes
include, but are not limited to:
TABLE-US-00006 Virus Epitope Reference HIV gp120 V3 loop, 308-331
Jatsushita, S. et al (1988) J. Viro. 62: 2107 HIV GP120 AA 428-443
Ratner et al (1985) Nature 313: 277 HIV gp120 AA 112-124 Berzofsky
et al (1988) Nature 334: 706 HIV Reverse transcriptase Hosmalin et
al (1990) PNAS USA 87: 2344 Flu nucleoprotein Townsend et al (1986)
AA 335-349, 366-379 Cell 44: 959 Flu haemagglutinin Mills et al
(1986) AA48-66 J. Exp. Med. 163: 1477 Flu AA111-120 Hackett et al
(1983) J. Exp. Med 158: 294 Flu AA114-131 Lamb, J. and Green N.
(1983) Immunology 50: 659 Epstein-Barr LMP43-53 Thorley-Lawson et
al (1987) PNAS USA 84: 5384 Hepatitis B Surface Ag AA95-109; Milich
et al (1985) AA 140-154 J. Immunol. 134: 4203 Pre-S antigen Milich,
et al. (1986) AA 120-132 J. Exp. Med. 164: 532 Herpes simplex gD
protein AA5-23 Jayaraman et al (1993) J. Immunol. 151: 5777 gD
protein AA241-260 Wyckoff et al (1988) Immunobiology 177: 134
Rabies glycoprotein AA32-44 MacFarlan et al (1984) J. Immunol 133:
2748
Bacteria-Associated Epitopes
The epitope may also be associated with a bacterial antigen.
Suitable epitopes include, but are not limited to:
TABLE-US-00007 Bacteria Epitope ID Reference Tuberculosis 65 Kd
protein Lamb et al (1987) AA112-126 EMBO J. 6: 1245 AA163-184
AA227-243 AA242-266 AA437-459 Staphylococcus nuclease protein
Finnegan et al (1986) AA61-80 J. Exp. Med 164: 897 E. coli heat
stable enterotoxin Cardenas et al (1993) Infect Immunity 61: 4629
heat labile entertoxin Clements et al (1986) Infect. Immunity 53:
685 Shigella sonnei form I antigen Formal et al (1981) Infect.
Immunity 34: 746
Cancer-Associated Epitopes
In another embodiment, the epitope is associated with a cancer
(tumor), including but not limited to cancers of the respiratory
system (lung, trachea, larynx), digestive system (mouth, throat,
stomach, intestines) excretory system (kidney, bladder, colon,
rectum), nervous system (brain), reproductive system (ovary,
uterus, cervix), glandular system (breast, liver, pancreas,
prostate), skin, etc. The two main groups of cancers are sarcomas,
which are of mesenchymal origin and affect such tissues as bones
end muscles, and carcinomas, which are of epithelial origin and
make up the great majority of the glandular cancers of breasts,
stomach, uterus, skin and tongue. The sarcomas include
fibrosarcomas, lymphosarcomas, osteosarcomas, chondrosarcomas,
rhabdosarcomas and liposarcomas. The carcinomas include
adenocarcinomas, basal cell carcinomas and squamous carcinomas.
Cancer-associated epitopes include, but are not limited to, peptide
epitopes such as those of mutant p53, the point mutated Ras
oncogene gene product, her 2/neu, c/erb2, and the MUC1 core
protein, and carbohydrate epitopes such as sialyl Tn (STn), TF, Tn,
CA 125, sialyl Le.sup.x, sialyl Le.sup.a and P97.
Carbohydrate Epitopes
Carbohydrate epitopes are also of interest. For example, any of
three types of tumor-associated carbohydrate epitopes which are
highly expressed in common human cancers may be presented. These
particularly include the lacto series type 1 and type 2 chains,
cancer associated ganglio chains, and neutral glycosphingolipids.
Examples of the lacto series Type 1 and Type 2 chains are as
follows: Lewis a, dimeric Lewis a, Lewis b, Lewis b/Lewis a, Lewis
x, Lewis, y, Lewis a/Lewis x. dimeric Lewis x, Lewis y/Lewis x,
trifucosyl Lewis y, trifucosyl Lewis b, sialosyl Lewis x, sialosyl
Lewis y, sialosyl dimeric Lewis x, Tn, sialosyl Tn, sialosyl TF,
TF. Examples of cancer-associated ganglio chains are as follows:
GM3. GD3, GM2, GM4, GD2, GM1, GD-1a, GD-1b. Neutral sphingolipids
include globotriose, globotetraose, globopentaose, isoglobotriose,
isoglobotetraose, mucotriose, mucotetraose, lactotriose,
lactotetraose, neolactotetraose, gangliotriose, gangliotetraose,
galabiose, and 9-O-acetyl-GD3.
Numerous antigens of clinical significance bear carbohydrate
determinants. One group of such antigens comprises the
tumor-associated mucins (Roussel, et al., Biochimie 70, 1471,
1988).
Generally, mucins are glycoproteins found in saliva, gastric
juices, etc., that form viscous solutions and act as lubricants or
protectants on external and internal surfaces of the body. Mucins
are typically of high molecular weight (often >1,000,000 Dalton)
and extensively glycosylated. The glycan chains of mucins are
O-linked (to serine or threonine residues) and may amount to more
than 80% of the molecular mass of the glycoprotein. Mucins are
produced by ductal epithelial cells and by tumors of the same
origin, and may be secreted, or cell-bound as integral membrane
proteins (Burchell, et al., Cancer Res., 47, 5476, 1987; Jerome, et
al., Cancer Res., 51, 2908, 1991).
Cancerous tissues produce aberrant mucins which are known to be
relatively less glycosylated than their normal counter parts (Hull,
et al., Cancer Commun., 1, 261, 1989). Due to functional
alterations of the protein glycosylation machinery in cancer cells,
tumor-associated mucins typically contain short, incomplete
glycans. Thus, while the normal mucin associated with human milk
fat globules consists primarily of the tetrasaccharide glycan, gal
.beta.1-4 glcNAcpl-6(gal .beta.1-3) gal NAc-.alpha. and its
sialylated analogs (Hull, et al.), the tumor-associated Tn hapten
consists only of the monosaccharide residue,
.alpha.-2-acetamido-3-deoxy-D-galactopyranosyl, and the T-hapten of
the disaccharide
.beta.-D-galactopyranosyl-(1-3).alpha.-acetamido-2-deoxy-D-galactopyranos-
yl. Other haptens of tumor-associated mucins, such as the sialyl-Tn
and the sialyl-(2-6)T haptens, arise from the attachment of
terminal sialyl residues to the short Tn and T glycans (Hanisch, et
al., Biol. Chem. Hoppe-Sevler, 370, 21, 1989; Hakormori, Adv.
Cancer Res., 52:257, 1989; Torben, et al., Int. J. Cancer, 45 666,
1980; Samuel, et al., Cancer Res., 50, 4801, 1990).
The T and Tn antigens (Springer, Science, 224, 1198, 1984) are
found in immunoreactive form on the external surface membranes of
most primary carcinoma cells and their metastases (>90% of all
human carcinomas). As cancer markers, T and Tn permit early
immunohistochemical detection and prognostication of the
invasiveness of some carcinomas (Springer). Recently, the presence
of the sialyl-Tn hapten on tumor tissue has been identified as an
unfavorable prognostic parameter (Itzkowitz, et al. Cancer, 66,
1960, 1990; Yonezawa, et al., Am. J. Clin. Pathol., 98 167, 1992).
Three different types of tumor-associated carbohydrate antigens are
highly expressed in common human cancers. The T and Tn haptens are
included in the lacto series type, and type 2 chains. Additionally,
cancer-associated ganglio chains and glycosphingolipids are
expressed on a variety of human cancers.
The altered glycan determinants displayed by the cancer associated
mucins are recognized as non-self or foreign by the patient's
immune system (Springer). Indeed, in most patients, a strong
autoimmune response to the T hapten is observed. These responses
can readily be measured, and they permit the detection of
carcinomas with greater sensitivity and specificity, earlier than
has previously been possible. Finally, the extent of expression of
T and Tn often correlates with the degree of differentiation of
carcinomas. (Springer).
An extensive discussion of carbohydrate haptens appears in Wong,
U.S. Pat. No. 6,013,779. A variety of carbohydrates can be
incorporated into a synthetic glycolipopeptide immunogen, according
to the present invention, for use particularly in detecting and
treating tumors. The Tn, T, sialyl Tn and sialyl (2-->6)T
haptens are particularly preferred.
In particular, for detecting and treating tumors, the three types
of tumor-associated carbohydrate epitopes which are highly
expressed in common human cancers are conjugated to aminated
compounds. These particularly include the lacto series type 1 and
type 2 chain, cancer associated ganglio chains, and neutral
glycosphingolipids.
Examples of the lacto series Type 1 and Type 2 chains are as
follows:
Lacto Series Type A and Type 2 Chain
TABLE-US-00008 Lewis a: Fuc.alpha. 1 .dwnarw. 4
Ga1.beta.1.fwdarw.3G1cNAc.beta.1.fwdarw. dimeric Lewis a:
Fuc.alpha. 1 Fuc.alpha. 1 .dwnarw. .dwnarw. 4 4
Ga1.beta.1.fwdarw.3G1cNAc.beta.1.fwdarw.Ga1.beta.1.fwdarw.3G1cNAc.beta.1.f-
wdarw. Lewis b: Fuc.alpha. 1 .dwnarw. 4
Ga1.beta.1.fwdarw.3G1cNAc.beta.1.fwdarw. 2 .uparw. Fuc.alpha. 1
Lewis b/Lewis a: Fuc.alpha. 1 Fuc.alpha. 1 .dwnarw. .dwnarw. 4 4
Ga1.beta.1.fwdarw.3G1cNac.beta.1.fwdarw.Ga1.beta.1.fwdarw.G1cNac.beta.1.f-
wdarw. 2 .uparw. Fuc.alpha. 1 Lewis x:
Ga1.beta.1.fwdarw.4G1cNAc.beta.1.fwdarw. 3 .uparw. Fuc.alpha. 1
Lewis y: Ga1.beta.1.fwdarw.4G1cNAc.beta.1.fwdarw. 2 3 .uparw.
.uparw. Fuc.alpha. 1 Fuc.alpha. 1 Lewis a/Lewis x:
Ga1.beta.1.fwdarw.3G1cNAc.beta.1.fwdarw.3Ga1.beta.1.fwdarw.4G1cNAc.beta..f-
wdarw. 3 .uparw. Fuc.alpha. 1 Lewis x/Lewis x (dimeric Le.sup.x):
Ga1.beta.1.fwdarw.4G1cNAc.beta.1.fwdarw.3Ga1.beta.1.fwdarw.4G1cNAc.beta.
3 3 .uparw. .uparw. Fuc.alpha. 1 Fuc.alpha. 1 Lewis y/Lewis x:
Ga1.beta.1.fwdarw.4G1cNAc.beta.1.fwdarw.3Ga1.beta.1.fwdarw.4G1cNAc.bet-
a..fwdarw. 2 3 3 .uparw. .uparw. .uparw. Fuc.alpha. 1 Fuc.alpha. 1
Fuc.alpha. 1 Trifucosyl Lewis y:
Ga1.beta.1.fwdarw.4G1cNAc.beta.1.fwdarw.3Ga1.beta.1.fwdarw.4G1cNAc.bet-
a.1.fwdarw. 2 3 3 .uparw. .uparw. .uparw. Fuc.alpha. 1 Fuc.alpha. 1
Fuc.alpha. 1 3Ga1.beta.1.fwdarw.4G1c.beta.1.fwdarw. Trifucosyl
Lewis b: Fuc.alpha. 1 .dwnarw.
Ga1.beta.1.fwdarw.3G1cNAc.beta.1.fwdarw.3Ga1.beta.1.fwdarw.4G1cNAc.bet-
a.1.fwdarw. 2 3 .uparw. .uparw. Fuc.alpha. 1 Fuc.alpha. 1
3Ga1.beta.1.fwdarw.4G1c.beta.1.fwdarw. Sialosyl Le.sup.x:
NeuAc.alpha.2.fwdarw.3Ga1.beta.1.fwdarw.4G1cNAc.beta.1.fwdarw. 3
.uparw. Fuc.alpha. 1 Sialosyl Le.sup.a: Fuc.alpha. 1 .dwnarw. 4
NeuAc.alpha.2.fwdarw.3Ga1.beta.1.fwdarw.3GlcNAc.beta.1.fwdarw.
Sialosyl Dimeric Le.sup.x:
NeuAc.alpha.2.fwdarw.3Ga1.beta.1.fwdarw.4G1cNAc.beta.1.fwdarw.3Ga1.beta.1.-
fwdarw.4G1cNAc.beta.1.fwdarw. 3 3 .uparw. .uparw. Fuc.alpha. 1
Fuc.alpha. 1 Tn: GalNAc.alpha.1.fwdarw. Sialosyl-Tn:
NeuAc.alpha..fwdarw.6Ga1NAc.alpha.1.fwdarw. Sialosyl-T:
NeuAc.alpha..fwdarw.6 (Ga1.beta.1.fwdarw.3) Ga1NAc.alpha.1.fwdarw.
NeuAc.alpha..fwdarw.6Ga1NAc.alpha.1.fwdarw. 3 .dwnarw. Ga1.beta. 1
T: Ga1.beta.1.fwdarw.3Ga1NAc.alpha.1.fwdarw.
Examples of cancer-associated ganglio chains that can be conjugated
to aminated compounds according to the present invention are as
follows:
Cancer Associated Ganglio Chains
TABLE-US-00009 GM3:
NeuAc.alpha.2.fwdarw.3Ga1.beta.1.fwdarw.4G1c.beta.1.fwdarw. GD3:
NeuAc.alpha.2.fwdarw.8NeuAc.alpha.2.fwdarw.3Ga1.beta.1.fwdarw.4G1c.beta.1.-
fwdarw. GM2:
Ga1NAc.beta.1.fwdarw.4Ga1.beta.1.fwdarw.4G1c.beta.1.fwdarw. 3
.uparw. NeuAc.alpha. 2 GM4:
NeuAc.alpha.2.fwdarw.3Gal.beta.1.fwdarw. GD2:
Ga1NAc.beta.1.fwdarw.4Ga1.beta.1.fwdarw.4G1c.beta.1.fwdarw. 3
.uparw. NeuAc.alpha.2.fwdarw.8NeuAc.alpha. 2 GM1:
Ga1.beta.1.fwdarw.3Ga1NAc.beta.1.fwdarw.4Ga1.beta.1.fwdarw.4G1c.beta.1.fwd-
arw. 3 .uparw. NeuAc.alpha. 2 GD-1a:
NeuAc.alpha.2.fwdarw.3Ga1.beta.1.fwdarw.3Ga1NAc.beta.1.fwdarw.4Gal.beta.1.-
fwdarw.4G1c.beta.1.fwdarw. 3 .uparw. NeuAc.alpha. 2 GD-1b:
Ga1.beta.1.fwdarw.3Ga1NAc.beta.1.fwdarw.4Ga1.beta.1.fwdarw.4G1c.beta.1.-
fwdarw. 3 .uparw. NeuAc.alpha.2.fwdarw.8NeuAc.alpha. 2
In addition to the above, neutral glycosphingolipids can also be
conjugated to aminated compounds according to the present
invention:
Selected Neutral Glycosphingolipids
Globotriose:
Gal.alpha..fwdarw.4Gal.beta.1.fwdarw.4Glc.beta.1.fwdarw.
Globotetraose:
GalNAc.beta.1.fwdarw.3Gal.alpha..fwdarw.4Gal.beta.1.fwdarw.4Glc.beta.1.fw-
darw. Globopentaose:
GalNAc.alpha.1.fwdarw.3GalNAc.beta.1.fwdarw.3Gal.alpha..fwdarw.4Gal.beta.-
1.fwdarw.4Glc.beta.1.fwdarw. Isoglobotriose:
Gal.alpha..fwdarw.3Gal.beta.1.fwdarw.4Glc.beta.1.fwdarw.
Isoglobotetraose:
GalNAc.beta.1.fwdarw.3Gal.alpha.1.fwdarw.3Gal.beta.1.fwdarw.4Glc.beta.1.f-
wdarw. Mucotriose:
Gal.beta.1.fwdarw.4Gal.beta.1.fwdarw.4Glc.beta.1.fwdarw.
Mucotetraose:
Gal.beta.1.fwdarw.3Gal.beta.1.fwdarw.4Gal.beta.1.fwdarw.4Glc.beta.1.fwdar-
w. Lactotriose:
GalNAc.beta.1.fwdarw.3Gal.beta.1.fwdarw.4Glc.beta.1.fwdarw.
Lactotetraose:
GalNAc.beta.1.fwdarw.3GalNAc.beta.1.fwdarw.3Gal.beta.1.fwdarw.4Glc.beta.1-
.fwdarw. Neolactotetraose:
Gal.beta.1.fwdarw.4GlcNAc.beta.1.fwdarw.3Gal.beta.1.fwdarw.4Glc.beta.1.fw-
darw. Gangliotriose:
GalNAc.beta.1.fwdarw.4Gal.beta.1.fwdarw.4Glc.beta.1.fwdarw.
Gangliotetraose:
Gal.beta.1.fwdarw.GlcNAc.beta.1.fwdarw.4Gal.beta.1.fwdarw.4Glc.beta.1.fwd-
arw. Galabiose: Gal.alpha..fwdarw.4Gal.beta.1.fwdarw.
9-0-Acetyl-GD3:
9-0-Ac-NeuAc.alpha.2.fwdarw.8NeuAc.alpha.2.fwdarw.3Gal.beta.1.fwdarw.4Glc-
.beta.1.fwdarw. Clustered Epitopes
In some embodiments, more than one epitope is provided, and the
epitopes are clustered.
Carbohydrate epitope clusters have been reported in the literature,
but the significance of these have not yet been clearly defined.
See Reddish, et al., Glycoconjugate J., 14:549-60 (1997) (clustered
STn), Ragapathi, et al. Cancer Immunol. Immunother. 48:1-8 (1999).
Likewise, clusters of O-glycosylation sites have been reported. See
Gendler, et al., J. Biol. Chem., 263:12820 (1988).
The following U.S. patents use the phrase "clustered epitopes":
U.S. Pat. No. 6,376,463
U.S. Pat. No. 6,258,937
U.S. Pat. No. 6,180,371
U.S. Pat. No. 5,929,220
U.S. Pat. No. 5,888,974
U.S. Pat. No. 5,859,204
U.S. Pat. No. 5,744,446
The following U.S. patents recited "clustered" and "carbohydrate
epitopes":
U.S. Pat. No. 6,365,124
U.S. Pat. No. 6,287,574
U.S. Pat. No. 6,013,779
U.S. Pat. No. 5,965,544
U.S. Pat. No. 5,268,364
U.S. Pat. No. 4,837,306
Mucin Epitope
In a preferred embodiment, the epitope is an epitope of a
cancer-associated mucin. Mucins are glycoproteins characterized by
high molecular weight (>1,000,000 daltons) and extensive
glycosylation (over 80%). Mucins may be expressed extracellularly,
or as an integral cell membrane glycoprotein with distinct
external, transmembrane, and cytoplasmic domains. Cell membrane
mucins exist as flexible rods and protrude relatively great
distances from the cell surface forming an important component of
the glycocalyx (Jentoff, 1990) and the terminal carbohydrate
portions thereof are probably the first point of contact with
antibodies and cells of the immune system.
Abberant or cancer-associated mucins are known to be relatively
less glycosylated (Hull et al, 1989) and hence antigenically
different from their normal cell counterpart mucins exposing
normally cryptic carbohydrate--(Hanish et al, 1989; Torben et al,
1990; Samuel et al, 1990), peptide--(Burchell et al, 1987) and
perhaps even glycopeptide-epitopes. Therefore, because cell surface
mucins protrude, they themselves may serve as targets for immune
attack (Henningson, et al., 1987; Fung, et al., 1990; Singhal, et
al., 1991; Jerome et al., 1991; Oncogen, EP 268,279; Biomembrane
Institute, WO89/08711; Longenecker, U.S. Pat. No. 4,971,795). Under
some circumstances, cancer-associated cell membrane mucins can
actually "mask" other cell surface antigens and protect cancer
cells from immune attack (Codington et al, 1983; Friberg, 1972;
Miller et al, 1977).
The mucin epitope may be a core peptide, a carbohydrate, or a
glycopeptide. Non-limiting examples of mucins which may carry
epitopes are the human tumor associated Thomsen-Friedenreich
antigen, (MacLean, 1992), epiglycanin-related glycoprotein
(Codington, 1984) ovine submaillary mucin, bovine submaxillary
mucin, breast tumor mucins (e.g., human polymorphic epithelial
mucin, including breast tumor mucins, Gendler, 1988, 1990; breast
cancer epithelial tumor antigen, Hareuveni, 1990, breast carcinoma,
Hull, 1989), mammary tumor mucins (e.g., such as murine mammary
adenocarcinoma, Fung, 1990) carcinoma mucins such as mucins arising
from the kidney (e.g., renal cell carcinoma), ovary (e.g., ovarian
carcinoma-associated sebaceous gland antigen, Layton, 1990),
bladder, colon (e.g., Sialosyl-Tn in colorectal cancer, Itzkowitz,
1990) pancreatic tumor mucin (Lan, 1990), gallbladder, bladder,
colon (e.g., malignant colon mucosa mucins, Torbin, 1980) and some
lung tissues, melanoma mucins (e.g., melanoma-associated antigen,
Kahn, 1991) epithelial tumor cell mucins, leukemia associated
mucins, carcinoembryonic antigen, or any other mucin associated
with abnormal cells according to known characteristics of cancer
associated mucins or abnormal mucins, such as abberant
glycosylation (Hakomori, 1989, and Singhal, 1990).
MUC1 Epitopes
The human MUC1 gene product has been referred to by various names,
including MAM6, milk mucin; human milk fat globule antigen (HMFG);
human mammary epithelial antigen, CA 15-3, CA 27.29; episialin; and
polymorphic epithelial mucin (PEM) (reviewed in
Taylor-Papadimitriou et al, 1988) (for complete cites to the
incompletely cited references in this section, see Longenecker, et
al., Ser. No. 08/229,606). This mucin is strongly expressed on
human breast (Gendler et al, 1988), pancreatic (Lan et al, 1990)
and certain ovarian cancer cells (Layton et al, 1990). Although the
MUC1 encoded mucins expressed on various cancers contain the same
tandem repeat core peptide sequence, glycosylation differences do
exist (Gendler et al, 1988; Lan et al, 1990). Because of
underglycosylation in cancer cells, MUC-1 molecules on cancer cells
express cryptic epitopes which are not expressed (i.e, are cryptic)
on normal epithelial cells.
MUC1 is the first cancer-associated mucin gene to be cloned and
mapped (Gendler et al, 1990), and has recently been transfected
into a murine mammary cell line, 410.4 (Lalani et al, 1991). MUC1
transfected 410.4 cells express the MUC1 gene product on the cell
surface.
The pattern of glycosylation is similar to, but different from,
malignant cell derived mucins expressing the same cryptic peptide
epitopes as expressed by human cancer associated MUC1
(Taylor-Papadimitriou et al, 1988). Lalani and co-workers (1991)
have examined the immunogenicity of the 410.4 transfectants in
mice. These workers demonstrated that mice which rejected a low
dose of transfected 410.4 cells did not develop tumors after a
subsequent transplant of a high dose of transfected 410.4 cells
although no effect on tumor development of untransfected wild type
410.4 cells was seen (Taylor-Papadimitriou et al, 1988). (For
complete cites, see Longenecker5-USA, and see also refs 4-11
thereof).
It has been shown that cancer vaccines composed of synthetic
peptide antigens which mimic cryptic MUC-1 peptide sequences on
cancer cells are able to induce effective anti-cancer immunotherapy
against MUC-1 expressing tumor cells in a murine model Finn and
co-workers have shown that cancer patients are able to produce
specific non-MHC restricted cytotoxic T-lymphocytes (CTL) which
recognize peptide epitopes expressed on MUC-1 molecules on cancer
cells. (See refs. 12 and 53-55 of U.S. Ser. No. 08/229,606, docket
Longenecker5-USA, hereby incorporated by reference.) Indeed the
MUC1 sequence SAPDTRP (AAs 11-17 of SEQ ID NO: 2) has been shown to
be both a T-and a B-cell epitope. It has been demonstrated that the
immunization of chimpanzees with synthetic MUC-1 antigens induces
the development of specific antibodies and CMI against MUC-1.
The human epithelial mucin MUC1 is over-expressed in more than 90%
of carcinomas of the breast, ovary and pancreas, and in those
tumors it is aberrantly glycosylated. The SM3 antibody binds the
core protein of MUC1; it also binds the tumor glycoproteins,
presumably because the SM3 epitope is exposed as a result of the
aforementioned aberrant glycosylation.
The amino acid sequence of Human MUC1 is available in the
SWISS-PROT database as P15941. The number of repeats is highly
polymorphic. It varies from 21 to 125 in the northern european
population. The most frequent alleles contains 41 and 85 repeats.
The tandemly repeated icosapeptide underlies polymorphism at three
positions, as shown by brackets:
PAPGSTAP[P/A/Q/T]AHGVTSAP[D/E][T/S]R (SEQ ID NO: 5). The common
polymorphisms are the coordinated double mutation DT->ES and the
single replacements P->A, P->Q and P->T. The most frequent
replacement DT>ES occurs in up to 50% of the repeats. For Mouse
MUC1, see SWISS-PROT Q02496.
Moller, et al., Eur. J. Biochem. 269:1444-55 (March 2002) has used
NMR spectroscopy to study the binding of the SM3 antibody to the
pentapeptide MUC1 epitope PDTRP and to the related
glycopentapeptide in which the threonine is O-lined to
alpha-d-GalNAc. Moller found that the PDT interacted with the SM3
antibody more strongly than did the RP, suggesting that the RP
would be more tolerant of mutation. In contrast, the glycopeptide
interacted with SM3 using all of its amino acids, although the
strongest effect was with the Prol. Docking studies were conducted;
these could be performed with mutant peptides for which 3D
structures are deducible or determined.
Hiltbold, et al., Cancer Res., 58:5066-70 (1998) showed that CD4+
T-cells primed in vitro with a synthetic MUC1 peptide of 100 amino
acids, representing five unglycosylated tandem repeats, and
presented by dendritic cells, produced IFN-gamma and had moderate
cytolytic activity. They also identified a core peptide sequence,
PGSTAPPAHGVT (SEQ ID NO: 6), which elicits this response when it is
presented by HLA-DR3.
Heukamp, et al., Int. J. Cancer, 91:385-92 (2001) elicited
peptide-specific CTL immunity in A2/K(b) transgenic mice with three
MUC1-derived peptides that map outside the variable number tandem
repeat region. These peptides were MUC(79-87)(TLAPATEPA)(SEQ ID NO:
7), MUC(167-175)(ALGSTAPPV)(SEQ ID NO: 8) and
MUC(264-72)(FLSFHISNL)(SEQ ID NO: 9). All comply with the peptide
binding motif for HLA-A*0201.
Engelmann, et al., J. Biol. Chem. 276:27764-9 (July 2001) report
that there are three sequence variants in the tandem repeat region
of MUC1. Variant 1 replaced DT with ES.
Soares et al., J. Immunol. 166: 6555-63 (June 2001) used a seven
tandem repeat MUC1 peptide to elicit an immune response. If the
peptide was delivered on dendritic cells, it only elicited T cell
immunity. If injected together with soluble peptide, Ab production
was also triggered.
Von Mensdorff-Pouilly et al., J. Clin. Oncol. 18:574-83 (February
2000) used a MUC1 triple tandem repeat peptide conjugated to BSA in
an immunoassay of anti-MUC1 antibody levels in breast cancer
patients.
Denton, et al., Pept. Res. 7:258-64 (September/October 1994),
colinearly liked a MUC1 mucin B cell peptide epitope to a known
murine T cell epiope in both T-B and B-T orientations.
Brossart et al., Blood, 93:4309-17 (June 1999) analyzed the MUC1
amino acid sequence and identified two novel peptides with a high
binding probability to the HLA-A2 molecule. One was from the
variable tandem repeat region, and the other from outside it.
Carmon, et al., Int. J. Cancer, 85:391-7 (February 2000) evaluated
the anti-tumor potential of HLA-A2.1 motif-selected peptides from
non-tandem repeat regions of the molecule. See also Pietersz et
al., Vaccine, 18:2059-71 (April 2000).
Keil, et al. Angew. Chem. Int. Ed. Engl. 40:366-9(January 2001)
conjugated a MUC1 epitope to a tetanus toxin epitope.
Schreiber, et al., Anticancer Res. 20:3093-8(September/October
2000) showed that the peptide with five MUC1 tandem repeats had
three times the binding affinity for the bacterial heat shock
protein DnaK (mammalian heat shock proteins are involved in antigen
processing) as did the peptide with just one repeat.
Von Mensdorff-Pouilly et al., Int. J. Cancer, 86:702-12 (June 2000)
reported that the most frequent minimal epitopic sequences of
natural MUC1 IgG and IgM antibodies were RPAPGS (AAs 9-14 of SEQ ID
NO: 10), PPAHGVT (SEQ ID NO: 11; equivalent to AAs 17-20 followed
by AAS 1-3 of SEQ ID NO:10) and PDTRP (AAs 6-10 of SEQ ID NO: 10).
MUC1 peptide vaccination induced high titers of IgM and IgG
antibodies predominantly directed, respectively, to the PDTRPAP
(AAs6-12 of SEQ ID NO: 10) and the STAPPAHGV (AAs 1-9 of SEQ ID
NO:2) sequences of the tandem repeat. Natural MUC abs from breast
cancer patients reacted more strongly with GalNac-glycosylated
peptides than with unglycosylated peptides.
See also EP Appl 1,182,210; Sandrin, U.S. Pat. No. 6,344,203; Finn,
U.S. Pat. No. 5,744,144.
See also, Petrakou, et al., "Epitope Mapping of Anti-MUC1 Mucin
protein Core Monoclonal Antibodies" (21-29); Imai, et al., "Epitope
Characterization of MUC1 Antibodies" (30-34), Schol, et al.,
"Epitope Fingerprinting Using Overlapping 20-mer peptides of the
MUC1 Tandem repeat sequence" (35-45), and Blockzjil, "Epitope
characterization of MUC1 Antibodies" (46-56), all in ISOBM TD-4
International Workshop on Monoclonal Antibodies against MUC1
November 1996), reprinted in Tumor Biology, 19 Suppl. 1: 1-152
(1998).
See also Von Mensdorff-Pouilly, et al., "Human MUC1 mucin: a
multifacted glycoprotein," Int J. Biol. Markers, 15:343-56
(2000)
The present invention therefore contemplates immunogens which
comprise at least one native B and/or T cell epitope of MUC1, or at
least one mutant epitope substantially identical to such a native
epitope. It may further comprise additional MUC1 sequence which is
not part of an epitope.
Preferably, theimmunogen comprises both a B cell epitope and a T
cell epitope of MUC1 (which, in each case, may be a natural epitope
or an allowed mutant thereof), and these epitopes may be identical,
overlapping, or distinct.
T and B cell epitopes of an antigen may overlap. For example, in
the case of MUC-1, SAPDTRP (AAs 4-10 of SEQ ID NO:10) is a T-cell
epitope, while PDTRP (AAs 6-10 of SEQ ID NO:10) is merely a B-cell
epitope.
It may further comprise additional B cell epitopes, and/or
additional T cell epitopes. The B cell epitopes may be the same or
different, and likewise the T cell epitopes may be the same or
different.
If the immunogen of the present invention comprises a MUC1-related
sequence at least substantially identical to a MUC1 sequence of at
least five amino acids, the MUC1-related sequence may comprise one
or more glycosylation sites found in the corresponding MUC1
sequence. It may differ from the corresponding MUC1 sequence in the
number of potential glycosylation sites, as a result of mutation,
or it may have the same number of potential glycosylation
sites.
The potential glycosylation sites may be (1) sites actually
glycosylated in the MUC1-derived tumor glycoprotein, (2) sites
potentially glycosylatable but not actually glycosylated in that
tumor glycoprotein, and/or (3) sites foreign to said glycoprotein.
Likewise, the actual glycosylation sites may be (1) sites actually
glycosylated in the MUC1-derived tumor glycoprotein, (2) sites
potentially glycosylatable but not actually glycosylated in that
tumor glycoprotein, and/or (3) sites foreign to said glycoprotein.
None, one, some or all of the glycosylation sites normally
glycosylated in the MUC1-derived tumor glycoprotein may be
glycosylated in the immunogen of the present invention.
MUC1 is a polymorphic antigen characterized by a variable number
(typically 21-125, especially 41 or 85) of perfect and imperfect
repeats of the following sequence:
TABLE-US-00010 GVTSAPDTRPAPGSTAPPAH (SEQ ID NO: 10)
Since there are multiple repeats of this sequence, the starting
point shown is arbitrary, and an epitope may bridge two repeats.
Consequently, the immunogens of the present invention may comprise
the aforementioned complete repeat sequence or a cyclic permutation
thereof. Moreover, they may comprise two or more copies of the
aforementioned repeat or a cyclic permutation thereeof. Thus, in
compounds 1a and 1b, there are two copies of a cyclic permutation
(starting at TSA . . . and ending with HGV) of the above sequence,
followed by the unrelated SSL sequence.
Each MUC1 epitope in question may correspond to an epitope of the
variable tandem repeat region, or to an epitope outside that
region. The former include RPAPGS (AAs 9-14 of SEQ ID NO:10),
PPAHGVT (SEQ ID NO:11) and PDTRP (AAs 6-10 of SEQ ID NO:10). The
sequence PDTRPAPGS (AAs 6-14 of SEQ ID NO:10) is of particular
interest, as it includes two overlapping epitopes. The PDTRP
sequence forms the tip of a protruding knob exposed to solvents and
forming a stable type II beta-turn.
The non-VNTR region epitopes include MUC(79-87)(TLAPATEPA)(SEQ ID
NO:7), MUC(167-175)(ALGSTAPPV)(SEQ ID NO:8) and
MUC(264-72)(FLSFHISNL)(SEQ ID NO:9).
Preferably, the immunogen comprises the polymorphic epitope
P[D/E][T/S]RP or a substantially identical mutant thereof. More
preferably it comprises PDTRP (AAs 6-10 of SEQ ID NO:10) or a
substantially identical mutant thereof.
In some embodiments, the immunogen comprises at least one 20 amino
acid sequence (an effective tandem repeat) which differs solely by
one or more conservative substitutions and/or a single
nonconservative substitution from a tandem repeat of MUC1, and
comprises an epitope of the variable tandem repeat region of MUC1
(either identically, or an allowed mutant). Preferably, it differs
solely, if at all, by conservative substitutions, more preferably,
by no more than a single conservative substitutions, and most
preferably, is identical to such a tandem repeat. It should be
noted that the tandem repeats of MUC1 are imperfect and hence the
sequence could be identical to one repeat but not to another. Also,
there are allelic variations in these repeats, and so the sequence
could be identical to the sequence for one allele and not for
another.
In a subset of these embodiments, the immunogen comprises a
plurality of nonoverlapping effective tandem repeats, such as two
(for a total of 40 amino acids), three (for a total of 60 amino
acids), four, five, six, seven or eight. These effective tandem
repeats may, but need not be, identical to each other. (In
contrast, note that in the natural human MUC1 mucin, the number of
repeats is typically 21-125.)
Besides one or more effective tandem repeats, the peptide portion
of the immunogen may comprise additional amino acid subsequences.
If so, these subsequences may comprise additional epitopes, which
may be MUC1 variable tandem repeat region epitopes (falling short
of a effective tandem repeat), MUC1 epitopes from outside that
region, or epitopes of other cancer antigens. It may also include
an immunomodulatory element, see Longenecker, et al., Ser. No.
08/229,606.
Preferably, one or more of the serines and/or threonines of the
MUC1 tandem repeat are glycosylated, preferably with Tn or sialyl.
Tn. In the natural human MUC1 mucin, there are five normal
glycosylation sites per repeat. In normal MUC1, an average of 2.6
of these five sites is in fact occupied. The average number of
glycosylated amino acids per repeat may be less than, the same as,
or greater than the "natural" value.
Preferably, the immunogen is lipidated, as disclosed in Koganty, et
al., U.S. Provisional Appl. 60/377,595, filed May 6, 2002 (docket:
Koganty4.1-USA), incorporated by reference. More preferably, it
comprises, in its C-terminal region, the sequence SSL, where both
serines are lipidated.
Identification of Naturally Occurring Epitopes
Other naturally occurring epitopes may be identified by the methods
set forth in Koganty et al., U.S. Prov. 60/377,595
(Koganty4.1-USA).
Mutant Epitopes
Generally speaking, in addition to epitopes which are identical to
the naturally occurring disease- or tumor-specific epitopes, the
present invention embraces epitopes which are different from but
substantially identical with such epitopes, and therefore disease-
or tumor-specific in their own right. It also includes epitopes
which are not substantially identical to a naturally occurring
epitope, but which are nonetheless cross-reactive with the latter
as a result of a similarity in 3D conformation.
One class of allowable modifications of the amino acid sequence of
a peptide moiety are amino acid substitutions. Conservative
substitutions replace an amino acid with another of like size,
charge and polarity; these are less likely to substantially alter
the conformation of the peptide. The types of substitutions which
may be made in the protein or peptide molecule of the present
invention may be based on analysis of the frequencies of amino acid
changes between a homologous protein of different species, such as
those presented in Table 1-2 of Schulz et al., supra and FIGS. 3-9
of Creighton, supra. Based on such an analysis, conservative
substitutions are defined herein as exchanges within one of the
following five groups:
TABLE-US-00011 TABLE V 1. Small aliphatic, nonpolar or slightly
polar residues: Ala, Ser, Thr (Pro, Gly); 2. Polar, negatively
charged residues and their amides: Asp, Asn, Glu, Gln; 3. Polar,
positively charged residues: His, Arg, Lys; 4. Large aliphatic,
nonpolar or slightly polar residues: Met, Leu, Ile, Val (Cys); and
5. Large aromatic residues: Phe, Tyr, Trp. Groups 1-3 are somewhat
related and mutations within that set may be considered
semi-conservative. Similarly, mutations within groups 4-5 may be
considered semi- conservative.
Residues Pro, Gly and Cys are parenthesized because of their
special role in protein architecture. Pro imparts rigidity to the
peptide chain, and has a tendency to interfere with alpha helix
formation. Gly imparts flexibility to the peptide chain, and is
often found in "loops" between alpha helices or beta strands. The
thiol groups of cysteine residues can be oxidized to form disulfide
bonds between nonadjacent cysteinyl residues.
Within the foregoing groups, the following substitutions are
considered "highly conservative": Asp/Glu His/Arg/Lys Phe/Tyr/Trp
Met/Leu/Ile/Val
Semi-conservative substitutions are defined to be exchanges between
two of groups (I)-(V) above which are limited to supergroup (A),
comprising (I), (II) and (III) above, or to supergroup (B),
comprising (IV) and (V) above. Also, Ala is considered a
semi-conservative substitution for all non group I amino acids.
An epitope is considered substantially identical to a reference
epitope (e.g., a naturally occurring epitope) if it has at least
10% of an immunological activity of the reference epitope and
differs from the reference epitope by no more than one
non-conservative substitution (except as provided below).
Preferably, any non-conservative substitution is a
semi-conservative substitution. Preferably, there are no
non-conservative substitutions.
There may be any number of conservative substitutions. Preferably,
there are no more than three such substitutions, more preferably,
not more than two, and still more preferably, not more than
one.
It will be appreciated that highly conservative substitutions are
less likely to affect activity than other conservative
substitutions, conservative substitutions are less likely to affect
activity than merely semi-conservative substitutions, and
semi-conservative substitutions less so than other non-conservative
substitutions. In addition, single substitutions are less likely to
affect activity than are multiple mutations.
Although a substitution mutant, either single or multiple, of the
peptides of interest may not have quite the potency of the original
peptide, such a mutant may well be useful.
Substitutions are not limited to the genetically encoded, or even
the naturally occurring amino acids. When the epitope is prepared
by peptide synthesis, the desired amino acid may be used directly.
Alternatively, a genetically encoded amino acid may be modified by
reacting it with an organic derivatizing agent that is capable of
reacting with selected side chains or terminal residues.
A non-genetically encoded amino acid is considered a conservative
substitution for a genetically encoded amino acid if it is more
similar in size (volume) and hydrophobicity (lipophilicity) to the
original amino acid, and to other amino acids in the same exchange
group, than it is to genetically encoded amino acids belonging to
other exchange groups.
Methods of identifying mutant epitopes are further described in
Koganty et al., U.S. Prov. 60/377,595 (Koganty4.1-USA).
Analogues
Also of interest are analogues of the disclosed compounds.
Analogues may be identified by assigning a hashed bitmap structural
fingerprint to the compound, based on its chemical structure, and
determining the similarity of that fingerprint to that of each
compound in a broad chemical database. The fingerprints are
determined by the fingerprinting software commercially distributed
for that purpose by Daylight Chemical Information Systems, Inc.,
according to the software release current as of Jan. 8, 1999. In
essence, this algorithm generates a bit pattern for each atom, and
for its nearest neighbors, with paths up to 7 bonds long. Each
pattern serves as a seed to a pseudorandom number generator, the
output of which is a set of bits which is logically ored to the
developing fingerprint. The fingerprint may be fixed or variable
size.
The database may be SPRESI'95 (InfoChem GmbH), Index Chemicus
(ISI), MedChem (Pomona/Biobyte), World Drug Index (Derwent),
TSCA93(EPA) May bridge organic chemical catalog (Maybridge),
Available Chemicals Directory (MDLIS Inc.), NCI96 (NCI), Asinex
catalog of organic compounds (Asinex Ltd.), or IBIOScreen SC and NP
(Inter BioScreen Ltd.), or an inhouse database.
A compound is an analogue of a reference compound if it has a
daylight fingerprint with a similarity (Tanamoto coefficient) of at
least 0.85 to the Daylight fingerprint of the reference
compound.
A compound is also an analogue of a reference compound id it may be
conceptually derived from the reference compound by isosteric
replacements.
Homologues are compounds which differ by an increase or decrease in
the number of methylene groups in an alkyl moiety.
Classical isosteres are those which meet Erlenmeyer's definition:
"atoms, ions or molecules in which the peripheral layers of
electrons can be considered to be identical". Classical isosteres
include
TABLE-US-00012 Monovalents Bivalents Trivalents Tetra Annular F,
OH, NH.sub.2, CH.sub.3 --O-- --N.dbd. .dbd.C.dbd. --CH.dbd.CH--
.dbd.Si.dbd. Cl, SH, PH.sub.2 --S-- --P.dbd. --N+.dbd. --S-- Br
--Se-- --As-- .dbd.P+.dbd. --O-- I --Te-- --Sb-- .dbd.As+.dbd.
--NH-- --CH.dbd. .dbd.Sb+.dbd.
Nonclassical isosteric pairs include --CO-- and --SO.sub.2--,
--COOH and --SO.sub.3 H, --SO.sub.2NH.sub.2 and --PO(OH)NH.sub.2,
and --H and --F, --OC(.dbd.O)-- and C(.dbd.O)O--, --OH and
--NH.sub.2.
Characterizing the Immune Response
A cell-mediated immune response may be assayed in vitro or in vivo.
The conventional in vitro assay is a T cell proliferation assay. A
blood sample is taken from an individual who suffers from the
disease of interest, associated with that disease, or from a
vaccinated individual. The T cells of this individual should
therefore be primed to respond to a new exposure to that antigen by
proliferating. Proliferation requires thymidine because of its role
in DNA replication.
Generally speaking, T cell proliferation is much more extensive
than B cell proliferation, and it may be possible to detect a
strong T cell response in even an unseparated cell population.
However, purification of T cells is desirable to make it easier to
detect a T cell response. Any method of purifying T cells which
does not substantially adversely affect their antigen-specific
proliferation may be employed. In our preferred procedure, whole
lymphocyte populations would be first obtained via collection (from
blood, the spleen, or lymph nodes) on isopycnic gradients at a
specific density of 10.7, ie Ficoll-Hypague or Percoll gradient
separations. This mixed population of cells could then be further
purified to a T cell population through a number of means. The
simplest separation is based on the binding of B cell and
monocyte/macrophage populations to a nylon wool column. The T cell
population passes through the nylon wool and a >90% pure T
population can be obtained in a single passage. Other methods
involve the use of specific antibodies to B cell and or monocyte
antigens in the presence of complement proteins to lyse the non-T
cell populations (negative selection). Still another method is a
positive selection technique in which an anti-T cell antibody (CD3)
is bound to a solid phase matrix (such as magnetic beads) thereby
attaching the T cells and allowing them to be separated (e.g.,
magnetically) from the non-T cell population. These may be
recovered from the matrix by mechanical or chemical disruption.
Once a purified T cell population is obtained it is cultured in the
presence of irradiated antigen presenting cells (splenic
macrophages, B cells, dendritic cells all present). (These cells
are irradiated to prevent them from responding and incorporating
tritiated thymidine). The viable T cells (100,000-400,000 per well
in 100 .mu.l media supplemented with IL2 at 20 units) are then
incubated with test peptides or other antigens for a period of 3 to
7 days with test antigens at concentrations from 1 to 100
.mu.g/mL.
At the end of the antigen stimulation period a response may be
measured in several ways. First the cell free supernatants may be
harvested and tested for the presence of specific cytokines. The
presence of .alpha.-interferon, IL2 or IL12 are indicative of a Th
helper type 1 population response. The presence of IL4, IL6 and
IL10 are together indicative of a T helper type 2 immune response.
Thus this method allows for the identification of the helper T cell
subset.
A second method termed blastogenesis involves the adding tritiated
thymidine to the culture (e.g., 1 .mu.curie per well) at the end of
the antigen stimulation period, and allowing the cells to
incorporate the radiolabelled metabolite for 4-16 hours prior to
harvesting on a filter for scintillation counting. The level of
radioactive thymidine incorporated is a measure of the T cell
replication activities. Negative antigens or no antigen control
wells are used to calculated the blastogenic response in terms of a
stimulation index. This is CPM test/CPM control. Preferably the
stimulation index achieved is at least 2, more preferably at least
3, still more preferably 5, most preferably at least 10. CMI may
also be assayed in vivo in a standard experimental animal, e.g., a
mouse. The mouse is immunized with a priming antigen. After waiting
for the T cells to respond, the mice are challenged by footpad
injection of the test antigen. The DTH response (swelling of the
test mice is compared with that of control mice injected with,
e.g., saline solution.
Preferably, the response is at least 0.10 mm, more preferably at
least 0.15 mm, still more preferably at least 0.20 mm, most
preferably at least 0.30 mm.
The humoral immune response, in vivo, is measured by withdrawing
blood from immunized mice and assaying the blood for the presence
of antibodies which bind an antigen of interest. For example, test
antigens may be immobilized and incubated with the samples, thereby
capturing the cognate antibodies, and the captured antibodies then
measured by incubating the solid phase with labeled anti-isotypic
antibodies.
Preferably, the humoral immune response, if desired, is at least as
strong as that represented by an antibody titer of at least 1/100,
more preferably at least 1/1000, still more preferably at least
1/10,000.
Pharmaceutical Compositions and Methods
Subjects
The recipients of the vaccines of the present invention may be any
vertebrate animal which can acquire specific immunity via a humoral
or cellular immune response.
Among mammals, the preferred recipients are mammals of the Orders
Primata (including humans, apes and monkeys), Arteriodactyla
(including horses, goats, cows, sheep, pigs), Rodenta (including
mice, rats, rabbits, and hamsters), and Carnivora (including cats,
and dogs). Among birds, the preferred recipients are turkeys,
chickens and other members of the same order. The most preferred
recipients are humans.
The preferred animal subject of the present invention is a primate
mammal. By the term "mammal" is meant an individual belonging to
the class Mammalia, which, of course, includes humans. The
invention is particularly useful in the treatment of human
subjects, although it is intended for veterinary uses as well. By
the term "non-human primate" is intended any member of the suborder
Anthropoidea except for the family Hominidae. Such non-human
primates include the superfamily Ceboidea, family Cebidae (the New
World monkeys including the capuchins, howlers, spider monkeys and
squirrel monkeys) and family Callithricidae (including the
marmosets); the superfamily Cercopithecoidea, family
Cercopithecidae (including the macaques, mandrills, baboons,
proboscis monkeys, mona monkeys, and the sacred hunaman monkeys of
India); and superfamily Hominoidae, family Pongidae (including
gibbons, orangutans, gorillas, and chimpanzees). The rhesus monkey
is one member of the macaques.
Immunostimulatory Compositions
The present invention contemplates use of at least one
pharmaceutical composition comprising at least one
immunostimulatory oligonucleotide molecule as disclosed above.
This immunostimulatory composition may be used by itself to
nonspecifically increase or otherwise alter the immunological state
of readiness of a subject.
Thus, it may be administered, other than in conjunction with a
pharamaceutically administered immunogen, to enhance the innate
immune response to an immunogen presented by a microbial or
non-microbial pathogen, or by a cancer. It may thereby be used to
increase a subject's resistance to contracting a disease, or to
treat an existing disease. In these uses, it optionally may be used
in conjunction with a non-immunological agent directed against said
disease, e.g., an antibiotic for treating a bacterial
infection.
Or it may be used as part of or otherwise in conjunction with a
pharmaceutical composition comprising an immunogen, which elicits a
specific immune response protective against a disease, in which
case it will have the effect of potentiating that disease-specific
response. Again, these immunological agents may be used in
conjunction with non-immunological agents directed against said
disease.
Some of the pharmaceutical compositions of the present invention
comprise at least one immunogen in an amount effective to elicit a
protective immune response. The response may be humoral, cellular,
or a combination thereof. The composition may comprise a plurality
of immunogens.
At least one immunogen is preferably either a glycolipopeptide
which is immunogenic per se, or a glycolipopeptide which is
immunogenic as a result of its incorporation into a liposome.
Glycolipopeptides are described in U.S. Provisional Appl.
60/377,595, filed May 6, 2002 (docket Koganty4.1-USA), incorporated
by reference in its entirety.
The immunogen may be administered before, after, or at the same
time as the immunostimulatory oligonucleotide is administered. If
administered simultaneously, they may be presented in a single
composition, or in different compositions; different compositions
can be administered by different routes. The oligonucleotide
molecule then is considered to be an adjuvant, although other
adjuvants may also be used, and although it may have useful
activities other than that of nonspecific immunostimulation.
It is furthermore possible to combine the functions of the
immunogen and the immunostimulatory oligonucleotide into a single
molecule comprising at least one CxG dinucleotide unit, at least
one lipophilic group, and at least one epitope.
The pharmaceutical composition preferably further comprises a
liposome. Preferred liposomes include those identified in Jiang, et
al., PCT/US00/31281, filed Nov. 15, 2000 (our docket JIANG3A-PCT),
and Longenecker, et al., Ser. No. 08/229,606, filed Apr. 12, 1994
(our docket LONGENECKER5-USA, and PCT/US95/04540, filed Apr. 12,
1995 (our docket LONGENECKER5-PCT).
The composition may comprise antigen-presenting cells, and in this
case the immunogen may be pulsed onto the cells, prior to
administration, for more effective presentation.
The composition may contain auxiliary agents or excipients which
are known in the art. See, e.g., Berkow et al, eds., The Merck
Manual, 15th edition, Merck and Co., Rahway, N.J., 1987; Goodman et
al., eds., Goodman and Gilman's The Pharmacological Basis of
Therapeutics, 8th edition, Pergamon Press, Inc., Elmsford, N.Y.,
(1990); Avery's Drug Treatment: Principles and Practice of Clinical
Pharmacology and Therapeutics, 3rd edition, ADIS Press, LTD.,
Williams and Wilkins, Baltimore, Md. (1987), Katzung, ed. Basic and
Clinical Pharmacology, Fifth Edition, Appleton and Lange, Norwalk,
Conn. (1992), which references and references cited therein, are
entirely incorporated herein by reference.
A pharmaceutical composition may further comprise an adjuvant,
other than the instant immunostimulatory lipidated
oligonucleotides, to nonspecifically enhance the immune response.
Some adjuvants potentiate both humoral and cellular immune
response, and other s are specific to one or the other. Some will
potentiate one and inhibit the other. The choice of adjuvant is
therefore dependent on the immune response desired.
A pharamceutical composition may include other immunomodulators,
such as cytokines which favor or inhibit either a cellular or a
humoral immune response, or inhibitory antibodies against such
cytokines.
A pharmaceutical composition according to the present invention may
comprise at least one cancer chemotherapeutic compound, such as one
selected from the group consisting of an anti-metabolite, a
bleomycin peptide antibiotic, a podophyllin alkaloid, a Vinca
alkaloid, an alkylating agent, an antibiotic, cisplatin, or a
nitrosourea.
A pharmaceutical composition may comprise at least one viral
chemotherapeutic compound selected from gamma globulin, amantadine,
guanidine, hydroxybenzimidazole, interferon-.alpha.,
interferon-.beta., interferon-.gamma., thiosemicarbarzones,
methisazone, rifampin, ribvirin, a pyrimidine analog, a purine
analog, foscarnet, phosphonoacetic acid, acyclovir,
dideoxynucleosides, or ganciclovir. See, e.g., Katzung, supra, and
the references cited therein on pages 798-800 and 680-681,
respectively, which references are herein entirely incorporated by
reference.
A pharmaceutical composition may comprise at least one
antibacterial agent. Such agents include penicillins,
cephalosporins, chloramphenicol, tetracyclines, aminoglycosides,
polymyxins, sulfonamides, and trimethoprim. Some specific agents of
particular interest are amoxicillin; ampicillin; benzylpenicillin;
chloramphenicol; clindamycin; enrofloxacin; erythromycin;
lincomycin; and rifampicin.
A pharmaceutical composition may comprise at least one
anti-parasitic agent. Anti-parasitic agents include agents suitable
for use against arthropods, helminths (including roundworns,
pinworms, threadworms, hookworms, tapeworms, whipworms, and
Schistosomes), and protozoa (including amebae, and malarial,
toxoplasmoid, and trichomonad organisms). Examples include
thiabenazole, various pyrethrins, praziquantel, niclosamide,
mebendazole, chloroquine HCl, metronidazole, iodoquinol,
pyrimethamine, mefloquine HCl, and hydroxychloroquine Hcl.
A pharmaceutical composition may comprise at least one agent which
ameliorates a symptom of the disease. Symptoms include, e.g., pain
and fever.
These various active agents can be administered as part of the same
composition as said immunogen or said immunostimulatory lipidated
oligonucleotide molecule, as part of a separate composition
administered simultaneously, or as part of a separate composition
administered at a different time to the subject.
Pharmaceutical Purposes
A purpose of the invention is to protect subjects against a
disease. The term "protection", as in "protection from infection or
disease", as used herein, encompasses "prevention," "suppression"
or "treatment." "Prevention" involves administration of a
Pharmaceutical composition prior to the induction of the disease.
"Suppression" involves administration of the composition prior to
the clinical appearance of the disease. "Treatment" involves
administration of the protective composition after the appearance
of the disease. Treatment may be ameliorative or curative.
It will be understood that in human and veterinary medicine, it is
not always possible to distinguish between "preventing" and
"suppressing" since the ultimate inductive event or events may be
unknown, latent, or the patient is not ascertained until well after
the occurrence of the event or events. Therefore, it is common to
use the term "prophylaxis" as distinct from "treatment" to
encompass both "preventing" and "suppressing" as defined herein.
The term "protection," as used herein, is meant to include
"prophylaxis." See, e.g., Berker, supra, Goodman, supra, Avery,
supra and Katzung, supra, which are entirely incorporated herein by
reference, including all references cited therein.
The "protection" provided need not be absolute, i.e., the disease
need not be totally prevented or eradicated, provided that there is
a statistically significant improvement (p=0.05) relative to a
control population. Protection may be limited to mitigating the
severity or rapidity of onset of symptoms of the disease. An agent
which provides protection to a lesser degree than do competitive
agents may still be of value if the other agents are ineffective
for a particular individual, if it can be used in combination with
other agents to enhance the level of protection, or if it is safer
than competitive agents.
The effectiveness of a treatment can be determined by comparing the
duration, severity, etc. of the disease post-treatment with that in
an untreated control group, preferably matched in terms of the
disease stage.
The effectiveness of a prophylaxis will normally be ascertained by
comparing the incidence of the disease in the treatment group with
the incidence of the disease in a control group, where the
treatment and control groups were considered to be of equal risk,
or where a correction has been made for expected differences in
risk.
In general, prophylaxis will be rendered to those considered to be
at higher risk for the disease by virtue of family history, prior
personal medical history, or elevated exposure to the causative
agent.
Pharmaceutical Administration
At least one protective agent of the present invention may be
administered by any means that achieve the intended purpose, using
a pharmaceutical composition as previously described.
Administration may be oral or parenteral, and, if parenteral,
either locally or systemically. For example, administration of such
a composition may be by various parenteral routes such as
subcutaneous, intravenous, intradermal, intramuscular,
intraperitoneal, intranasal, transdermal, or buccal routes.
Parenteral administration can be by bolus injection or by gradual
perfusion over time. A preferred mode of using a pharmaceutical
composition of the present invention is by subcutaneous,
intramuscular or intravenous application. See, e.g., Berker, supra,
Goodman, supra, Avery, supra and Katzung, supra, which are entirely
incorporated herein by reference, including all references cited
therein.
A typical regimen for preventing, suppressing, or treating a
disease or condition which can be alleviated by an immune response
by active specific immunotherapy, comprises administration of an
effective amount of a pharmaceutical composition as described
above, administered as a single treatment, or repeated as enhancing
or booster dosages, over a period up to and including between one
week and about 24 months.
It is understood that the effective dosage will be dependent upon
the age, sex, health, and weight of the recipient, kind of
concurrent treatment, if any, frequency of treatment, and the
nature of the effect desired. The ranges of effective doses
provided below are not intended to limit the invention and
represent preferred dose ranges. However, the most preferred dosage
will be tailored to the individual subject, as is understood and
determinable by one of skill in the art, without undue
experimentation. This will typically involve adjustment of a
standard dose, e.g., reduction of the dose if the patient has a low
body weight. See, e.g., Berkow et al, eds., The Merck Manual, 15th
edition, Merck and Co., Rahway, N.J., 1987; Goodman et al., eds.,
Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th
edition, Pergamon Press, Inc., Elmsford, N.Y., (1990); Avery's Drug
Treatment: Principles and Practice of Clinical Pharmacology and
Therapeutics, 3rd edition, ADIS Press, LTD., Williams and Wilkins,
Baltimore, Md. (1987), Ebadi, Pharmacology, Little, Brown and Co.,
Boston, (1985); Chabner et al., supra; De Vita et al., supra;
Salmon, supra; Schroeder et al., supra; Sartorelli et al., supra;
and Katsung, supra, which references and references cited therein,
are entirely incorporated herein by reference.
Prior to use in humans, a drug will first be evaluated for safety
and efficacy in laboratory animals. In human clinical studies, one
would begin with a dose expected to be safe in humans, based on the
preclinical data for the drug in question, and on customary doses
for analogous drugs (if any). If this dose is effective, the dosage
may be decreased, to determine the minimum effective dose, if
desired. If this dose is ineffective, it will be cautiously
increased, with the patients monitored for signs of side effects.
See, e.g., Berkow, et al., eds., The Merck Manual, 15th edition,
Merck and Co., Rahway, N.J., 1987; Goodman, et al., eds., Goodman
and Gilman's The Pharmacological Basis of Therapeutics, 8th
edition, Pergamon Press, Inc., Elmsford, N.Y., (1990); Avery's Drug
Treatment: Principles and Practice of Clinical Pharmacology and
Therapeutics, 3rd edition, ADIS Press, LTD., Williams and Wilkins,
Baltimore, Md. (1987), Ebadi, Pharmacology, Little, Brown and Co.,
Boston, (1985), which references and references cited therein, are
entirely incorporated herein by reference.
The total dose required for each treatment may be administered in
multiple doses (which may be the same or different) or in a single
dose, according to an immunization schedule, which may be
predetermined or ad hoc. The schedule is selected so as to be
immunologically effective, i.e., so as to be sufficient to elicit
an effective immune response to the antigen and thereby, possibly
in conjunction with other agents, to provide protection. The doses
adequate to accomplish this are defined as "therapeutically
effective doses." (Note that a schedule may be immunologically
effective even though an individual dose, if administered by
itself, would not be effective, and the meaning of "therapeutically
effective dose" is best interpreted in the context of the
immunization schedule.) Amounts effective for this use will depend
on, e.g., the peptide composition, the manner of administration,
the stage and severity of the disease being treated, the weight and
general state of health of the patient, and the judgment of the
prescribing physician.
Typically, the daily dose of an active ingredient of a
pharmaceutical, for a 70 kg adult human, is in the range of 10
nanograms to 10 grams. For immunogens, a more typical daily dose
for such a patient is in the range of 10 nanograms to 10
milligrams, more likely 1 microgram to 10 milligrams. However, the
invention is not limited to these dosage ranges.
It must be kept in mind that the compositions of the present
invention may generally be employed in serious disease states, that
is, life-threatening or potentially life threatening situations. In
such cases, in view of the minimization of extraneous substances
and the relative nontoxic nature of the peptides, it is possible
and may be felt desirable by the treating physician to administer
substantial excesses of these peptide compositions.
The doses may be given at any intervals which are effective. If the
interval is too short, immunoparalysis or other adverse effects can
occur. If the interval is too long, immunity may suffer. The
optimum interval may be longer if the individual doses are larger.
Typical intervals are 1 week, 2 weeks, 4 weeks (or one month), 6
weeks, 8 weeks (or two months) and one year. The appropriateness of
administering additional doses, and of increasing or decreasing the
interval, may be reevaluated on a continuing basis, in view of the
patient's immunocompetence (e.g., the level of antibodies to
relevant antigens).
The appropriate dosage form will depend on the disease, the
immunogen, and the mode of administration; possibilities include
tablets, capsules, lozenges, dental pastes, suppositories,
inhalants, solutions, ointments and parenteral depots. See, e.g.,
Berker, supra, Goodman, supra, Avery, supra and Ebadi, supra, which
are entirely incorporated herein by reference, including all
references cited therein.
The immunogen may be delivered in a manner which enhances
immunogenicity, e.g., delivering the antigenic material into the
intracellular compartment such that the "endogenous pathway" of
antigen presentation occurs. For example, the immunogen may be
entrapped by a liposome (which fuses with the cell), or
incorporated into the coat protein of a viral vector (which infects
the cell).
Another approach, applicable when the immunogen is a peptide, is to
inject naked DNA encoding the immunogen into the host,
intramuscularly. The DNA is internalized and expressed.
It is also possible to prime autologous PBLs with the compositions
of the present invention, confirm that the PBLs have manifested the
desired response, and then administer the PBLs, or a subset
thereof, to the subject.
Liposome Formulations
Liposomes are microscopic vesicles that consist of one or more
lipid bilayers surrounding aqueous compartments. See e.g.,
Bakker-Woudenberg et al., Eur. J. Clin. Microbiol. Infect. Dis. 12
(Suppl. 1): S61 (1993) and Kim, Drugs, 46: 618 (1993). Because
liposomes can be formulated with bulk lipid molecules that are also
found in natural cellular membranes, liposomes generally can be
administered safely and are biodegradable.
Liposomes are globular particles formed by the physical
self-assembly of polar lipids, which define the membrane
organization in liposomes. Liposomes may be formed as uni-lamellar
or multi-lamellar vesicles of various sizes. Such liposomes, though
constituted of small molecules having no immunogenic properties of
their own, behave like macromolecular particles and display strong
immunogenic characteristics.
A variety of methods are available for preparing liposomes, as
described in, e.g., Szoka et al., Ann. Rev. Biophys. Bioeng. 9:467
(1980), U.S. Pat. Nos. 4,235,871, 4,501,728, 4,837,028, and
5,019369, incorporated herein by reference.
Depending on the method of preparation, liposomes may be
unilamellar or multilamellar, and can vary in size with diameters
ranging from about 0.02 microm to greater than about 10 microm. A
variety of agents can be encapsulated in liposomes. Hydrophobic
agents partition in the bilayers and hydrophilic agents partition
within the inner aqueous space(s). See e.g., Machy et al.,
Liposomes in Cell Biology and Pharmacology (John Libbey, 1987), and
Ostro et al., American J. Hosp. Pharm. 46: 1576 (1989).
Liposomes can adsorb to virtually any type of cell and then release
an incorporated agent. Alternatively, the liposome can fuse with
the target cell, whereby the contents of the liposome empty into
the target cell. Alternatively, a liposome may be endocytosed by
cells that are phagocytic. Endocytosis is followed by
intralysosomal degradation of liposomal lipids and release of the
encapsulated agents. Scherphof et al., Ann. N.Y. Acad. Sci., 446:
368 (1985).
Other suitable liposomes that are used in the methods of the
invention include multilamellar vesicles (MLV), oligolamellar
vesicles (OLV), unilamellar vesicles (UV), small unilamellar
vesicles (SUV), medium-sized unilamellar vesicles (MUV), large
unilamellar vesicles (LUV), giant unilamellar vesicles (GUV),
multivesicular vesicles (MVV), single or oligolamellar vesicles
made by reverse-phase evaporation method (REV), multilamellar
vesicles made by the reverse-phase evaporation method (MLV-REV),
stable plurilamellar vesicles (SPLV), frozen and thawed MLV
(FATMLV), vesicles prepared by extrusion methods (VET), vesicles
prepared by French press (FPV), vesicles prepared by fusion (FUV),
dehydration-rehydration vesicles (DRV), and bubblesomes (BSV). The
skilled artisan will recognize that the techniques for preparing
these liposomes are well known in the art. See Colloidal Drug
Delivery Systems, vol. 66 (J. Kreuter, ed., Marcel Dekker, Inc.,
1994).
A "liposomal formulation"is an in vitro-created lipid vesicles in
which an antigen of the present invention can be incorporated.
Thus, "liposomally-bound" refers to a antigen that is partially
incorporated or attached to a liposome. The immunogen of the
present invention may be a liposomally-bound antigen which, but for
said liposome, would not be an immunogen, or it may be immunogenic
even in a liposome-free state.
Several different immunogens may be incorporated into the same
liposome, or each into a different liposome and the liposomes
administered together or separately to a subject.
A lipid-containing immunogen can be incorporated into a liposome
because the lipid portion of the molecule will spontaneously
integrate into the lipid bilayer. Thus, a glycolipopeptide may be
presented on the "surface" of a liposome. Alternatively, a peptide
may be encapsulated within a liposome. Techniques for preparing
liposomes and formulating them with molecules such as peptides are
well known to the skilled artisan.
Formation of a liposome requires one or more lipids. Any lipids may
be used which, singly or in combination, can form a liposome
bilayer structure. Usually, these lipids will include at least one
phospholipid. The phospholipids may be phospholipids from natural
sources, modified natural phospholipids, semisynthetic
phospholipids, fully synthetic phospholipids, or phospholipids
(necessarily synthetic) with normatural head groups. The
phospholipids of greatest interest are phosphatidyl cholines,
phosphatidyl phosphatidyl ethanolamines, phosphatidyl serines,
phosphatidyl glycerols, phosphatidic acids, and phosphatidyl
inositols.
The liposome may include neutral, positively charged, and/or
negatively charged lipids. Phosphatidyl choline is a neutral
phospholipid. Phosphatidyl glycerol is a negatively charged
glycolipid. N-[1-(2,3-dioleylox)propyl]-N,N,N-trimethylammonium
chloride is a positively charged synthetic lipid. Another is
3beta-[N--(N',N''-dimethylaminoethane)-carbamoyl]-cholesterol.
Usually, the lipids will comprise one or more fatty acid groups.
These may be saturated or unsaturated, and vary in carbon number,
usually from 12-24 carbons. The phospholipids of particular
interest are those with the following fatty acids: C12:0, C14:0,
C16:0, C18:0, C18:1, C18:2, C18:3 (alpha and gamma), C20:0, C20:1,
C20:3, C20:4, C20:5, C22:0, C22:5, C22:6, and C24:0, where the
first number refers to the total number of carbons in the fatty
acids chain, and the second to the number of double bonds. Fatty
acids from mammalian or plant sources all have even numbers of
carbon atoms, and their unsaturations are spaced at three carbon
intervals, each with an intervening methylene group.
A liposome may include lipids with a special affinity for
particular target cells. For example, lactosylceramide has a
specific affinity for hepatocytes (and perhaps also for liver
cancer cells).
In a preferred liposome formulation, the component lipids include
phosphatidyl choline. More preferably they also include
cholesterol, and still more preferably, also phosphatidyl glycerol.
Cholesterol reduces the permeability of "fluid-crystalline state"
bilayers.
Taking advantage of the self-assembling properties of lipids, one
or more immunogens may be attached to the polar lipids that in turn
become part of the liposome particle. Each immunogen comprises one
or more antigenic determinants (epitopes). These epitopes may be
B-cell epitopes (recognized by antibodies) or T-cell epitopes
(recognized by T-cells). The liposome can act to adjuvant the
immune response elicited by the associated immunogens. It is likely
to be more effective than an adjuvant that is simply mixed with an
immunogen, as it will have a higher local effective
concentration.
Moreover, a hapten may be attached in place of the aforementioned
immunogen. Like an immunogen, a hapten comprises an antigenic
determinant, but by definition is too small to elicit an immune
response on its own (typically, haptens are smaller than 5,000
daltons). In this case, the lipid moiety may act, not only as an
adjuvant, but also as an immunogenic carrier, the conjugate of the
hapten and the lipid acting as a synthetic immunogen (that is, a
substance against which humoral and/or cellular immune responses
may be elicited).
Even if the lipid does not act as an immunogenic carrier, the
liposome borne hapten may still act as a synthetic antigen (that
is, a substance which is recognized by a component of the humoral
or cellular immune system, such as an antibody or T-cell). The term
"antigen" includes both haptens and immunogens.
Adjuvants
It is generally understood that a synthetic antigen of low
molecular weight can be weakly immunogenic, which is the biggest
obstacle to the success of a fully synthetic vaccine. One way to
improve the imunogenicity of such a synthetic antigen is to deliver
it in the environment of an adjuvant. As conventionally known in
the art, adjuvants are substances that act in conjunction with
specific antigenic stimuli to enhance the specific response to the
antigen. An ideal adjuvant is believed to non-specifically
stimulate the immune system of the host, which upon the subsequent
encounter of any foreign antigen can produce strong and specific
immune response to that foreign antigen. Such strong and specific
immune response, which is also characterized by its memory, can be
produced only when T-lymphocytes (T-cells) of the host immune
system are activated.
T-cell blastogenesis and IFN-g production as two important
parameters for measuring the immune response. Experimentally,
T-cell blastogenesis measures DNA synthesis that directly relates
to T-cell proliferation, which in turn is the direct result of the
T-cell activation. On the other hand, IFN-g is a major cytokine
secreted by T-cells when they are activated. Therefore, both T-cell
blastogenesis and IFN-g production indicate T-cell activation,
which suggests the ability of an adjuvant in helping the host
immune system to induce a strong and specific immune response to
any protein-based antigen.
The compound is considered an adjuvant if it significantly (p=0.05)
increases the level of either T-cell blastogenesis or of interferon
gamma production in response to at least one liposome/immunogen
combination relative to the level elicited by the immunogen alone.
Preferably, it does both. Preferably, the increase is at least 10%,
more preferably at least 50%, still more preferably, at least
100%.
A large number of adjuvants are known in the art, including
Freund's complete adjuvant, saponin, DETOX (Ribi Immunochemicals),
Montanide ISA-51, -50 and -70, QS-21, monophosphoryl lipid A and
analogues thereof. A lipid adjuvant can be presented in the context
of a liposome.
Several adjuvants are especially suitable for adjuvanting a
liposome-delivered immunogen. Monophosphoryl lipid A (MPLA), for
example, is an effective adjuvant that causes increased
presentation of liposomal antigen to specific T Lymphocytes.
Alving, C. R., Immunobiol., 187:430-446 (1993). The skilled artisan
will recognize that lipid-based adjuvants, such as Lipid A and
derivatives thereof, are also suitable. A muramyl dipeptide (MDP),
when incorporated into liposomes, has also been shown to increase
adjuvancity (Gupta R K et al., Adjuvants-A balance between toxicity
and adjuvancity," Vaccine, 11, 293-306 (1993)).
The oligonucleotides of the present invention are of course capable
of serving as adjuvants, but other adjuvants may optionally be
used.
EXAMPLES
General: Melting points were not corrected. All air and moisture
sensitive reactions were performed under nitrogen atmosphere.
Anhydrous THF, DMF and dichloromethane were purchased from Aldrich
and other dry solvents were prepared in the usual way. ACS grade
solvents were purchased from Fisher and used for chromatography
without distillation. TLC plates (silica gel 60 F.sub.254,
thickness 0.25 mm, Merck) and flash silica gel 60 (35-75 .mu.m) for
column chromatography were purchased from Rose Scientific, Canada.
.sup.1H and .sup.31P spectra were recorded either on a Brucker A M
300 MHz, Brucker A M 400 MHz, Varian Unity 500 MHz, or Brucker DRX
600 MHz spectrometers with TMS as internal standard for proton
chemical shifts. Electron-spray mass spectrometric analyses were
performed either on a MS50B or MSD1 SPC mass spectrometers.
Example 1
Preparation of Compound 8
To a solution of 1,2-dodecandiol (5.0 g, 24.7 mmol) and DIPEA (3.86
g, 5.2 mL, 27.7 mmol) in DCM/THF (10:1, 500 mL) was slowly added
DMT-Cl solution (0.2 g, 27.2 mmol, in 100 mL DCM) over a period of
2 h at 0.degree. C. The mixture was stirred at 0.degree. C. for 3
h, followed by usual aqueous work-up. The product was purified by
flash chromatography (hexane/ethyl acetate, 3:1) to give 8 (6.5 g,
52%). C.sub.33H.sub.44O.sub.4 (504.44). TLC: R.sub.f=0.67
(hexane/ethyl acetate, 2:1). .sup.1H NMR (300 MHz, CDCl.sub.3):
.delta. 0.88 (t, J=6.5 Hz, 3 H), 1.24 (br s, 16 H), 1.37 (m, 2 H),
2.32 (d, J=3.5 Hz, 1 H, OH), 3.00 (dd, J=9.0, 7.0 Hz, 1 H), 3.16
(dd, J=9.0, 3.5 Hz, 1 H), 3.77 (m, 1 H), 3.79 (s, 6 H, 2
OCH.sub.3), 6.85-7.60 (m, 13 H, Ar--H).
Example 2
Preparation of Modified CPG Resin 9
Controlled pore glass (CPG) resin modified with
long-chain-amino-alkyl group (lcaa-CPG) (0.6 g, 57 .mu.mol) was
treated with succinic andydride (57 mg, 0.57 mmol) in DMF (1.5 mL)
overnight. Solvent was drained out and the resin washed with DMF
(.times.5). The process was repeated once. The unreacted free amine
on the resin was capped by treatment with NMI/Ac.sub.2O/THF (1:1:8,
v/v/v) for 5 min. The resin was then thoroughly washed with THF
(.times.5) and CH.sub.3CN (.times.5), dried under high vacuum to
give the succinic acid-attached support.
The succinic acid-attached CPG resin (0.3 g, .about.28.5 mmol) was
suspended in THF (2 mL) and 8 (43 mg, 85.5 .mu.mol), DIC (14
.mu.L), and DMAP (cat.) were added. The mixture was stirred at room
temperature for 12 h. the solvent was drained out and the reaction
was repeated once. The unreacted free carboxylic acid was capped by
treating with methanol/DIC/DMAP for 3 h. The resin was then
thoroughly washed with THF (.times.5) and DCM (.times.5), dried
under vacuum to afford the lipid-modified CPG resin 9.
Example 3
Preparation of Compound 1-5
a) De-tritylation
Lipid-modified CPG resin 9 (0.3 g, 28.5 .mu.mol) was treated with
trichloroacetic acid (TCA) (1% in DCM, w/v) for 5 min to remove the
DMT-group. The process was repeated once for 1 min, followed by
thorough wash with DCM (.times.5), acetonitrile (.times.5) and THF
(.times.3).
b) Coupling
The resin was then swelled in dry THF (2 mL), and phosphoramidite
reagent (42.8 .mu.mol, 1.5 eq.) and tetrazole (3.0 mg, 42.8 mol)
were added. The mixture was bubbled with N.sub.2 gas for 16 h.
After the removal of solvent and washing of the resin, the coupling
with phosphoramidite was repeated once.
c) Capping
The unreacted free hydroxyl group on the resin was capped by
treating with NMI/Ac.sub.2O/THF (1:1:8, v/v/v) for 5 min. followed
by thorough wash with DCM, acetonitrile and THF.
d) Oxidation
The resin was then treated with 2-butanone peroxide (, 2.0 mL, 0.1
M in DCM) for 5 min. and washed thoroughly with DCM, acetonitrile,
and THF.
The synthesis was continued by repeating the cycle of
De-tritylation, Coupling, Capping and Oxidation steps.
e) Cleavage and Final Deblocking
When the synthesis was complete, the resin was first treated with
TCA (1% in DCM, w/v) for 5 min to remove the 5'-end DMT protection
group, followed by thorough wash with DCM and acetonitrile. The
resin was then treated with 20% ammonium hydroxide (aq.) at
50-55.degree. C. for 24 h. The resin was filtered and the filtrate
concentrated in vacuo, and the residue was re-dissolved in
water-methanol (1:1) and purified by HPLC to give compound 1-5
(2.5-5.0 mg).
f) HPLC Conditions:
Column: Vydac C4 semi-Prep column, 10.times.250 mm; solvent A: 5%
acetonitrile in water with 50 mM triethyl ammonium acetate (TEAA),
pH=7.0; solvent B: 50% acetonitrile in water with 50 mM TEAA,
pH=7.0. Gradient: from 20% acetronitrile to 45% acetonitrile in 30
min. flow rate: 3.0 mL/min. UV detection at e260 nm.
g) Structure Confirmation
The structures of compound 1-5 were confirmed by electron spray
mass spectra data. Compound 1: C.sub.31H.sub.50N8O.sub.14P.sub.2
(820.44), ES-MS (m/z, negative mode) found: 819 (M-H). Compound 2:
C.sub.43H.sub.75N.sub.8O.sub.23P.sub.3 (1164.66), ES-MS (m/z,
negative mode) found: 1163 (M-H). Compound 3:
C.sub.73H.sub.104N.sub.22O.sub.39P.sub.6 (2098.86), ES-MS (m/z,
negative mode) found: 2098 (M-H), 2121 (M+Na-2 H). Compound 4:
C.sub.71H.sub.101N.sub.19O.sub.41P.sub.6 (2061.83), ES-MS (m/z,
negative mode) found: 2060 (M-H), 2083 (M+Na-2 H), 2105 (M+2Na-3
H), 2127 (M+3Nn-4 H), 2171 (M+5Na-6 H). Compound 5:
C.sub.71H.sub.100N.sub.22O.sub.38P.sub.6 (2054.82), ES-MS (m/z,
negative mode) found: 2054 (M-H), 2076 (M+Na-2 H), 2098 (M+2Na-3
H).
Example 4
Preparation of Compound 11
To a solution of 10 (5.0 g, 23.1 mmol) in dry DMF (200 ml) was
added slowly NaH (2.2 g, 91.7 mmol) at 0.degree. C. and the mixture
was stirred for 1 h. 1-Bromohexadecane (17.8 g, 17.8 mL, 58.4 mmol)
in DMF (30 mL) was added dropwise over a period of 1 h and the
resulting mixture was stirred at room temperature for 16 h. water
(5.0 ml) was added to quench the reaction and the DMF then removed
under vacuum. Usual aqueous work-up gave a yellow syrup (crude 23.0
g). The syrup was treated with DCM/TFA/water (100:2.5:0.25, 200 mL)
at room temperature for 3 h. The mixture was washed with water (50
mL.times.2) and sat. NaHCO.sub.3 (50 mL). The organic layer was
dried with Na.sub.2SO.sub.4, concentrated, and the residue was
purified by flash chromatography (hexane/ethyl acetate, 4:1 then
2:1) to give 11 (9.73 g, 72% for two steps).
C.sub.37H.sub.76O4 (585.01). TLC: R.sub.f=0.29 ((hexane/ethyl
acetate, 3:1). .sup.1H NMR (300 MHz, CDCl.sub.3): .delta. 0.88 (t,
J=6.5 Hz, 6 H, 2 CH.sub.3), 1.25 (br s, 52 H), 1.56 (m, 4 H), 2.85
(t, J=5.0 Hz, 2 H, 2 OH), 3.42 (t, J=6.5 Hz, 4 H), 3.51 (s, 4 H),
3.65 (d, J=5.0 Hz, 4 H).
Example 5
Preparation of Compound 12
Compound 11 (2.33 g, 4.00 mmol) was dissolved in dry pyridine (30
mL) and DCM (27 mL), and DMAP (46 mg, 0.38 mmol) was added. DMT-Cl
(1.49 g, 4.40 mmol) was dissolved in DCM (13 mL) and added dropwise
to the reaction flask. The reaction mixture was stirred at room
temperature for 3 h. Methanol (5 ml) was added to quench the
reaction and the solvent was removed by codistillation with
toluene. The residue was re-dissolved in DCM (400 mL) and the
solution was washed with sat. NaHCO.sub.3 (150 mL). The organic
layer was dried with Na.sub.2SO.sub.4, concentrated and the residue
purified by flash chromatography (hexane/ethyl acetate, 10:1 then
5:1) to give 12 (3.05 g, 86%). C.sub.58H.sub.94O.sub.6 (886.94).
TLC: R.sub.f=0.57 ((hexane/ethyl acetate, 5:1). .sup.1H NMR (500
MHz, CDCl.sub.3): .delta. 0.86 (t, J=6.5 Hz, 6 H, 2 CH.sub.3), 1.23
(br s, 52 H), 1.48 (m, 4 H), 2.95 (t, J=6.0 Hz, 1 H, OH), 3.09 (s,
2 H), 3.34 (m, 4 H), 3.45 (d, J=9.0 Hz, 2 H), 3.49 (d, J=9.0 Hz, 2
H), 3.66 (d, J=6.0 Hz, 2 H), 3.77 (s, 6 H, 2 OCH.sub.3), 6.78-7.41
(m, 13 H, Ar--H).
Example 6
Preparation of Compound 13
Compound 12 (423 mg, 0.48 mmol) was dissolved in pyridine (7 mL)
and succinic andydride (140 mg, 1.4 mmol) and DMAP (120 mg, 1.0
mmol) were added. The mixture was stirred at room temperature for
60 h and then concentrated by codistillation with toluene. The
residue was purified by flash chromatography (hexane/ethyl acetate,
4:1:2%, with 0.1% pyridine) to give 13 (425 mg, 94%). R.sub.f=0.19
(hexane/ethyl acetate, 5:1:2%). C.sub.62H.sub.98O.sub.9 (986.72).
ES-MS (m/z): found 1009.7 (M+Na). .sup.1H NMR (300 MHz,
CDCl.sub.3): .delta. 0.86 (t, J=6.5 Hz, 6 H, 2 CH.sub.3), 1.25 (br
s, 52 H), 1.48 (m, 4 H), 2.46-2.59 (m, 4 H), 3.09 (s, 2 H), 3.32
(t, J=6.5 Hz, 4 H), 3.36 (d, J=9.0 Hz, 2 H), 3.42 (d, J=9.0 Hz, 2
H), 3.80 (s, 6 H, 2 OCH.sub.3), 4.18 (s, 2 H), 6.80-7.43 (m, 13 H,
Ar--H).
Example 7
Preparation of Compound 14
To a solution of 13 (0.18 g, 0.18 mmol) and p-nitrophenol (33.8 mg,
0.24 mmol) in DCM (10 mL) was added DCC (50 mg, 0.24 mmol). The
mixture was stirred at room temperature for 6 h. Urea was filtered
out and the filtrate concentrated. The residue was purified by
flash chromatography (hexane/ethyl acetate, 4:1) to give 14 (0.18
g, 89%) as a clear syrup. C.sub.68H.sub.101NO.sub.11 (1108.01).
TLC: R.sub.f=0.75 (hexane/ethyl acetate, 3:1). .sup.1H NMR (500
MHz, CDCl.sub.3): .delta. 0.88 (t, J=6.5 Hz, 6 H, 2 CH.sub.3), 1.25
(br s, 52 H), 1.47 (m, 4 H), 2.59 (t, J=6.5 Hz, 2 H), 3.10 (s, 2
H), 3.32 (m, 4 H), 3.37 (d, J=9.0 Hz, 2 H), 3.41 (d, J=9.0 Hz, 2
H), 3.78 (s, 6 H), 2 OCH.sub.3), 4.20 (s, 2 H), 6.80-8.20 (m, 17 H,
Ar--H).
Example 8
Preparation of Modified CPG Resin 15
lcaa-CPG resin (1.0 g, 95 .mu.mol) was suspended in dry DMF (3.0
mL) and 14 (0.26 g, 235 .mu.mol) was added. DIPEA was added to
adjust the pH to 9 and the mixture was bubbled with N.sub.2 gas for
three days. The solvent was drained out and the resin successively
washed with DMF (.times.5) and DCM (.times.5). Unreacted free amine
on the resin was capped with (NMI)/Ac.sub.2O/THF (1:1:8, v/v/v) for
15 min. The resin was then thoroughly washed with acetonitrile
(.times.5) and DC M (.times.5) and dried under vacuum to give
lipid-modified CPG resin 15. The resin was tested with p-toluene
sulfonic acid (0.1 M in acetonitrile) to give orange color,
indicating the existence of DMT-group. Likewise, negative ninhydrin
test result indicates the absence of the free amine on the
resin.
Example 9
Preparation of Compound 18
Sodium hydride (817 mg, 34 mmol) was added to dry DMF (20 mL) and
compound 17 (3.0 g, 23 mmol, dissolved in 20 mL of dry DMF) was
added dropwise slowly at 0.degree. C. The mixture was stirred at
room temperature for 30 min and benzyl bromide (4.3 g, 2.97 mL, 25
mmol) was added dropwise slowly. The mixture was stirred at room
temperature for 2 h. The solvent was then removed under high vacuo,
followed by usual aqueous work-up. The crude product was purified
by flash chromatography (hexane/ethyl acetate, 6:1) to give 18
(4.65 g, 94%). TLC: R.sub.f=0.46 (hexane/ethyl acetate, 6:1).
C.sub.13H.sub.18O.sub.3 (222.13). ES-MS (positive mode, m/z) found:
245 (M+Na). .sup.1H NMR (300 MHz, CDCl.sub.3): .delta. 1.37 (s, 3
H, CH.sub.3), 1.42 (s, 3 H, CH.sub.3), 3.45 (dd, J=10.0, 5.5 Hz, 1
H), 3.55 (dd, J=10.0, 5.5 Hz, 1 H), 3.73 (dd, J=8.5, 6.5 Hz, 1 H),
4.04 (dd, J=8.56.5 Hz, 1 H), 4.30 (m, 1 H), 4.53 (d, J=12.0 Hz, 1
H), 4.59 (d, J=12.0 Hz, 1 H), 7.35 (m, 5 H, Ar--H).
Example 10
Preparation of Compound 19
Compound 18 (4.6 g, 20.7 mmol) was dissolved in HOAc--H.sub.2O
(4:1, 40 mL) and stirred at 40.degree. C. for 1.5 h. the solvent
was removed and the residue purified by flash chromatography
(hexane/ethyl acetate/methanol, 1:1:0.1) to give 19 (3.6 g, 95%).
TLC: R.sub.f=0.36 (hexane/ethyl acetate/methanol, 1:2:0.1).
C.sub.10H.sub.14O.sub.3 (182.09). .sup.1H NMR (300 MHz,
CDCl.sub.3): .delta. 3.55 (dd, J=10.0, 6.5 Hz, 1 H), 3.58 (dd,
J=10.0, 4.0 Hz, 1 H), 3.64 (dd, J=11.0, 5.5 Hz, 1 H), 3.71 (dd,
J=11.0, 3.5 Hz, 1 H), 3.90 (m, 1 H), 4.55 (s, 2 H).
Example 11
Preparation of Compound 20
Compound 19 (5.4 g, 29.6 mmol) was dissolved in dry acetonitrile
(700 ml) and triethyl amine (2.0 ml) was added. The mixture was
cooled to -50.degree. C. and benzoyl cyanide (3.5 g, 26.7 mmol,
dissolved in 150 mL of dry acetonitrile) was added dropwise slowly
under nitrogen atmosphere. The reaction mixture was further stirred
at -50.degree. C. for 1 h and the reaction was then quenched with
methanol (20 mL). Solvent was then removed and the residue was
purified by flash chromatography (hexane/ethyl acetate, 4:1) to
give 20 (5.1 g, 60%) and the unreacted starting material 19 (1.0 g,
18%) was recovered. TLC: R.sub.f=0.33 (hexane/ethyl acetate, 3:1).
C.sub.17H.sub.18O.sub.4 (286.12). ES-MS (positive mode, m/z) found:
287 (M+H), 309 (M+Na). .sup.1H NMR (300 MHz, CDCl.sub.3): .delta.
2.65 (d, J=5.0 Hz, 1 H, OH), 3.59 (dd, J=9.5, 6.0 Hz, 1 H), 3.65
(dd, J=9.5, 5.0 Hz, 1 H), 4.18 (m, 1 H), 4.39 (dd, J=11.0, 5.5 Hz,
1 H), 4.44 (dd, J=11.0, 4.5 Hz, 1 H), 4.59 (s, 2 H), 7.26-8.04 (m,
10 H, Ar--H).
Example 12
Preparation of Compound 21
Compound 20 (1.8 g, 6.29 mmol) was dissolved in dry dichloroethane
(20 mL) and paraformaldehyde (2.6 g) was added. The mixture was
kept at 0.degree. C. and HCl (g) was bubbled in for 3 h. HCl (g)
was then removed and dry calcium chloride was added and the mixture
stirred for 10 min. The solid was filtered and the washed with dry
dichloroethane. The filtrate was concentrated and the residue dried
briefly under high vacuo to afford crude 21 (2.0 g) which was used
directly for the next step reaction.
Example 13
Preparation of Compound 23
Method A Compound 22 (480 mg, 2.23 mmol) was dissolved in dry DMF
(10 mL) and sodium hydride (71 mg, 2.96 mmol) was added. The
mixture was stirred at room temperature for 40 min and crude 21
(500 mg, .about.1.48 mmol, dissolved in 2 mL of DCM) was added
dropwise slowly. The mixture was warmed to 60.degree. C. and
stirred for 20 h and then the reaction was quenched by adding
methanol (1 mL). Solvent was removed, followed by usual aqueous
work-up. From the organic layer, a viscous oily residue was
obtained which was purified by flash chromatography (hexane/ethyl
acetate/methanol, 1:1:0.01) to give 23 (230 mg, 30%).
Method B Compound 22 (480 mg, 2.23 mmol) was dissolved in dry DCM
(12 mL) and Bis(trimethylsilyl)acetamide (BSA, 640 mg, 3.14 mmol)
was added under nitrogen atmosphere. The mixture was stirred at
room temperature for 45 min and the clear solution cooled to
0.degree. C. Compound 21 (500 mg, .about.1.48 mmol, dissolved in 2
mL of DCM) and tetrabutyl ammonium iodide (8.0 mg, 0.02 mmol) were
added and the mixture was stirred at room temperature for 16 h. The
temperature was then brought to 60.degree. C. and the mixture
stirred for another 2 h. Dichloromethane (100 mL) was added and the
organic layer was washed with saturated sodium bicarbonate solution
(20 mL.times.3) and brine (20 mL), dried over sodium sulfate, and
concentrated. The residue was purified by flash chromatography
(hexane/ethyl acetate/methanol, 1:1:0.01) to give 23 (255 mg,
34%).
TLC: R.sub.f=0.33 (hexane/ethyl acetate/methanol, 1:2:0.1).
C.sub.19H.sub.27N.sub.3O.sub.6 (513.18). ES-MS (positive mode, m/z)
found: 514 M+H), 536 (M+Na). .sup.1H NMR (600 MHz, CDCl.sub.3):
.delta. 3.63 (dd, J=10.5, 6.0 Hz, 1 H), 4.34 (m, 1 H), 4.42 (dd,
J=12.0, 6.5 Hz, 1 H), 4.46 (dd, J=12.0, 4.0 Hz, 1 H), 4.53 (d,
J=12.0 Hz, 1 H), 4.57 (d, J=12.0 Hz, 1 H), 5.44 (d, J=10.5 Hz, 1
H), 5.51 (d, J=10.5 Hz, 1 H), 7.26 (m, 1 H), 7.34 (m, 4 H), 7.41
(m, 2 H), 7.49 (m, 1 H), 7.53 (m, 2 H), 7.63 (m, 1 H), 7.76 (br s,
1 H), 7.88 (br s, 2 H), 7.96 (m, 1 H), 7.98 (m, 1 H), 8.55 (br s, 1
H).
Example 14
Preparation of Compound 24
Compound 23 (800 mg, 1.56 mmol) was dissolved in dry DCM (65 mL)
and boron trichloride (1 M solution in DCM, 2.5 mL) was added
slowly at -78.degree. C. under nitrogen atmosphere. The mixture was
stirred at -78.degree. C. for 1 h. The reaction was quenched by
adding DCM-MeOH (1:1, 10 mL) and the solvent was removed. The
residue was purified by flash chromatography
(dichloromethane/methanol, 100:5) to give 24 (500 mg, 76%). TLC:
R.sub.f=0.58 (dichloromethane/methanol, 96:4).
C.sub.22H.sub.21N.sub.3O.sub.6 (423.13). ES-MS (positive mode,
m/z): 424.1 (M+H), 446.1 (M+Na). .sup.1H NMR (300 MHz, CDCl.sub.3):
.delta. 330 (br s, 1 H, OH), 3.76 (dd, J=12.0, 6.0 Hz, 1 H), 3.85
(dd, J=12.0, 4.0 Hz, 1 H), 4.23 (m, 1 H), 4.41 (dd, J=12.0, 6.0 Hz,
1 H), 4.48 (dd, J=12.0, 4.5 Hz, 1 H), 5.46 (d, J=11.0 Hz, 1 H),
5.51 (d, J=11.0 Hz, 1 H), 7.38-8.01 (m, 12 H, Ar--H), 9.00 (br s, 1
H).
Example 15
Preparation of Compound 25
Compound 24 (120 mg, 0.28 mmol) was dissolved in DCM (12 mL) and
diisopropyl ethyl amine (DIPEA, 0.5 mL) was added. Phosphoramidite
Cl--P(OCH.sub.2CH.sub.2CN)N(.sup.iPr).sub.2 (93 mg, 91.3 .mu.L,
0.39 mmol) was added under nitrogen atmosphere at room temperature.
The mixture was stirred for 30 min and then diluted with DCM (50
mL). The DCM layer was washed with 10% NaHCO.sub.3 solution (15 mL)
and brine (15 mL), dried, and concentrated. The residue was
purified by flash chromatography (hexane/ethyl acetate, 1:2, with
0.1% Et.sub.3N) to give 25 (140 mg, 79%). TLC: R.sub.f=0.54
(hexane/ethyl acetate, 1:2). C.sub.31H.sub.38N.sub.5O.sub.7P
(623.25). ES-MS (positive) found 624.2 (M+H), 646.2 (M+Na). .sup.1H
NMR (300 MHz, CDCl.sub.3): .delta. 1.18 (s, 6 H, 2 CH.sub.3), 1.20
(s, 6 H, 2 CH.sub.3), 2.68 (t, J=6.0 Hz, 2 H), 3.60 (m, 2 H), 3.85
(m, 4 H), 4.31 (m, 1 H), 4.38-4.55 (m, 2 H), 5.40 (dd, J=10.5, 1.5
Hz, 1 H), 5.57 (dd, J=10.5, 8.0 Hz, 1 H), 7.35-8.00 (m, 12 H), 9.00
(br s, 1 H). .sup.31P NMR (500 MHz, CDCl.sub.3): a 150 27,
150.40.
Example 16
Preparation of Compound 26
Compound 17 (500 mg, 0.47 mL, 3.78 mmol), tert-butyl diphenylsilyl
chloride (TBDPS-Cl, 1.25 g, 1.18 mL, 4.536 mmol) and imidazole (309
mg, 4.536 mmol) were dissolved in dry DMF (4 mL) and the mixture
was stirred at room temperature for 3 h. The solvent was removed,
followed by usual aqueous work-up. The product was purified by
flash chromatography (hexane/ethyl acetate, 10:1) to give 26 (1.4
g, 100%). TLC: R.sub.f=0.43 (hexane/ethyl acetate, 9:1).
C.sub.22H.sub.30O.sub.3Si (370.20). ES-MS (positive) found 393
(M+Na). .sup.1H NMR (300 MHz, CDCl.sub.3): .delta. 1.05 (s, 9 H, 3
CH.sub.3), 1.35 (s, 3 H, CH.sub.3), 1.39 (s, 3 H, CH.sub.3), 3.65
(dd, J=10.5, 6.5 Hz, 1 H), 3.74 (dd, J=10.5, 4.5 Hz, 1 H), 3.92
(dd, J=8.5, 6.0 Hz, 1H), 4.07 (dd, J=8.5, 6.5 Hz, 1 H), 4.20 (m, 1
H), 7.35-7.68 (m, 10 H).
Example 17
Preparation of Compound 27
Compound 26 (31.0 g, 83.78 mmol)<was treated with HOAc--H.sub.2O
(4:1, 100 mL) at 40.degree. C. for 40 min. The solvent was removed
and the residue purified by flash chromatography (hexane/ethyl
acetate, 10:1 and then 4;1) to give 27 (23.8 g, 95%). TLC:
R.sub.f=0.40 (hexane/ethyl acetate, 1:1). C.sub.19H.sub.26O.sub.3Si
(330.20). ES-MS (positive) found 353 (M+Na). .sup.1H NMR (400 MHz,
CDCl.sub.3): .delta. 1.05 (s, 9 H, 3 CH.sub.3), 2.60 (br s, 2 H, 2
OH), 3.64 (dd, J=11.5, 5.5 Hz, 1 H), 3.69 (dd, J=11.5, 4.0 Hz, 1
H), 3.70 (dd, J=10.0, 6.0 Hz, 1 H), 3.74 (dd, J=10.0, 4.5 Hz, 1 H),
3.81 (m, 1 H), 7.37-7.67 (m, 10 H, Ar--H).
Example 18
Preparation of Compound 28
To a solution of compound 27 (8.0 g, 24.2 mmol) and DIPEA (3.12 g,
4.2 mL, 24.2 mmol) in dry DCM (800 mL) was added dropwise slowly
the solution of 4,4'-dimethoxytrityl chloride (DMT-Cl, dissolved in
200 mL of DCM) at room temperature under nitrogen atmosphere, and
the mixture was stirred further for 2 h. The solvent was removed
and the product purified by flash chromatography (DCM/ethyl
acetate, 100:1, with 0.1% Et.sub.3N) to give 28 (12.3 g, 80%). TLC:
R.sub.f=0.35 (DCM/ethyl acetate, 100:2). C.sub.10H.sub.44O.sub.5Si
(632.24). ES-MS (positive) found 655 (M+Na). .sup.1H NMR (300 MHz,
CDCl.sub.3): .delta. 0.99 (s, 9 H, 3 CH.sub.3), 2.44 (d, J=5.0 Hz,
1H, OH), 3.77 (m, 2 H), 3.78 (s, 6 H, 2 OCH.sub.3), 3.88 (m, 1H),
6.80-7.85 (m, 23 H, Ar--H).
Example 19
Preparation of Compound 29
Compound 28 (3.20 g, 5.06 mmol) was dissolved in dry THF (100 mL)
and DIPEA (15 mL) was added. Methoxymethyl chloride (MOM-Cl, 4.89
g, 4.6 mL, 60.76 mmol) was added dropwise slowly at 0.degree. C.
and then the reaction mixture was stirred at 55.degree. C. for 5 h.
The mixture was cooled to 0.degree. C. and sat NaHCO.sub.3 (aq.)
(20 mL) was added. The organic layer was separated and the aqueous
layer extracted with ethyl acetate (3.times.40 mL). The combined
organic layer was dried over Na.sub.2SO4 and concentrated. The
residue was purified by flash chromatography (hexane/ethyl acetate,
10:1, with 0.1% Et.sub.3N) to give 29 (2.7 g, 79%). TLC:
R.sub.f=0.57 (hexane/ethyl acetate, 4:1). C.sub.42H.sub.48O.sub.6Si
(676.20). ES-MS (positive mode, m/z): found 699 (M+Na). .sup.1H NMR
(300 MHz, CDCl.sub.3): .delta. 1.00 (s, 9 H, 3 CH.sub.3), 3.21 (dd,
J=10.0, 6.0 Hz, 1 H), 3.27 (dd, J=10.0, 4.5 Hz, 1 H), 3.31 (s, 3 H,
OCH.sub.3), 3.74 (d, J=5.5 Hz, 2 H). 3.77 (s, 6 H, 2 OCH.sub.3),
3.91 (m, 1 H), 4.72 (d, J=11.5 Hz, 1 H), 4.75 (d, J=11.5 Hz, 1 H),
6.70-7.60 (m, 23 H, Ar--H).
Example 20
Preparation of Compound 31
Compound 29 (500 mg, 0.74 mmol) was dissolved in dry DCM (10 mL)
and DIPEA (2.0 mL) was added. Dimethylboron bromide solution (1.5 M
in DCM, 2.5 mL, 3.75 mmol) was added at -78.degree. C. and stirred
for 1 h. The reaction was slowly warmed to room temperature and
sodium iodide was added. The mixture was stirred at room
temperature for 16 h. Meanwhile, compound 30 (246 mg, 1.11 mmol)
was dissolved in dry DMF (6 mL) and sodium hydride (40 mg, 1.67
mmol) was added. The mixture was stirred at room temperature for 10
min and added slowly to the above reaction flask. The reaction
mixture was stirred at room temperature for 1 h, then at 60.degree.
C. for 16 h and finally at 80.degree. C. for 6 h. The solvent was
then removed and the residue purified by flash chromatography
(ethyl acetate/hexane/methanol, 2:1.5:0.1) to give 31 (185 mg.
29%). TLC: R.sub.f=0.57 (hexane/ethyl acetate/methanol, 5:10:1).
C.sub.50H.sub.55N.sub.5O.sub.7Si (865.40). ES-MS (positive mode,
m/z): found 866 (M+H). .sup.1H NMR (600 MHz, CDCl.sub.3): .delta.
0.95 (s, 9 H, 3 CH.sub.3), 1.25 (d, J=7.0 Hz, 3 H, CH.sub.3), 1.26
(d, J=7.0 Hz, 3 H, CH.sub.3), 2.72 (m, 1 H), 3.14 (dd, J=10.0, 6.5
Hz, 1 H), 3.18 (dd, J=10.0, 4.0 Hz, 1 H), 3.66 (d, J=5.5 Hz, 2 H),
3.76 (s, 6 H, 2 OCH.sub.3), 4.05 (m, 1 H), 5.84 (d, J=10.5 Hz, 1
H), 5.87 (d, J=10.5 Hz, 1 H), 6.76 (m, 4 H, Ar--H), 7.15-7.58 (m,
19 H, Ar--H), 7.89 (s, 1 H).
Example 21
Preparation of Compound 32
Compound 31 (220 mg, 0.254 mmol) was dissolved in dry THF (60 mL)
and tetrabutyl ammonium fluoride solution (1.0 M in THF, 0.51 mL,
0.51 mmol) was added. The mixture was stirred at room temperature
for 1 h and then the solvent was removed. The residue was purified
by flash chromatography (hexane/ethyl acetate/methanol, 1:2:0.5) to
give 32 (140 mg, 91%). TLC: R.sub.f=0.36 (hexane/ethyl
acetate/methanol, 1:2:0.5). C.sub.34H.sub.37N.sub.5O.sub.7
(627.28). ES-MS (positive mode, m/z) found: 650.3 (M+Na). .sup.1H
NMR (600 MHz, CDCl.sub.3): .delta. 1.16 (2 d, J=7.0 Hz, each 3 H, 2
CH.sub.3), 2.55 (m, 1 H), 3.05 (dd, J=10.5, 4.0 Hz, 1 H), 3.09 (dd,
J=10.5, 6.0 Hz, 1 H), 3.46 (dd, J=12.0, 7.0 Hz, 1 H), 3.49 (dd,
J=12.0, 3.5 Hz, 1 H), 3.69 (s, 6 H, 2 OCH.sub.3), 3.79 (m, 1 H),
5.75 (s, 2 H), 6.70-7.27 (m, 13 H), 7.85 (s, 1 H).
Example 22
Preparation of Compound 33
1-Tetradecanol (200 mg 0.933 mmol) and DIPEA (0.5 mL) were
dissolved in dry DCM (10 mL) and phosphoramidite reagent
Cl--P(OCH.sub.2CH.sub.2CN)N(.sup.iPr).sub.2 (265 mg, 260 .mu.L, 1.1
mmol) was added. The mixture was stirred at room temperature for 1
h and then diluted with DCM (50 mL). The DCM layer was washed with
10% NaHCO.sub.3 (aq.) (10 mL) and brine (10 mL), dried over
Na.sub.2SO.sub.4, and concentrated. The residue was purified by
flash chromatography (hexane/ethyl acetate, 1:4, with 1% Et.sub.3N)
to give 33 (382 mg, 100%) which was used directly in the next step
reaction.
Example 23
Preparation of Compound 34
The mixture of 32 (50 mg, 0.080 mmol), 33 (70 mg, 0.160 mmol) and
tetrazole (20 mg) in dry DCM (6 mL) was stirred at room temperature
for 1 h. Then 2-butanone peroxide solution (1 M in DCM, 1.0 mL) was
added and the reaction mixture was stirred at room temperature for
10 min. the solvent was removed and the residue purified by flash
chromatography (hexane/ethyl acetate/methanol, 1:2:0.5) to give 34
(53 mg, 79%). TLC: R.sub.f=0.22 (hexane/ethyl acetate/methanol,
1:2:0.2). C.sub.51H.sub.69N.sub.6O.sub.10P (956.48). ES-MS
(positive mode, m/z) found: 957 (M+H), 979 (M+Na) .sup.1H NMR (500
MHz, CDCl.sub.3): .delta. 0.88 (t, J=7.0 Hz, 3 H, CH.sub.3) 1.25
(m, 28 H, 11 CH.sub.2, 2 CH.sub.3), 1.64 (m, 2 H), 2.75 (m, 2 H),
2.88 (m, 1 H), 3.20 (m, 2 H), 3.80 (s, 6 H, 2 OCH.sub.3), 4.00 (m,
2 H), 4.05-4.24 (m, 5 H). 5.85 (m, 2 H), 6.80 (m, 4 H), 7.20 (m, 9
H), 8.00 (s, 1 H), 9.25 (s, 1 H), 12.20 (s, 1 H).
Example 24
Preparation of Compound 35
Compound 34 (150 mg, 0.157 mmol) was treated with trichloroacetic
acid solution (3% in DCM, w/v, 3 mL) at room temperature for 10
min. The mixture was concentrated in vacuo and the residue purified
by flash chromatography (ethyl acetate/DCM/methanol, 2:8:0.5) to
give 35 (101 mg, 99%). TLC: R.sub.f=0.31 (ethyl
acetate/DCM/methanol, 2:1:0.3). C.sub.30H.sub.51N.sub.6O.sub.8P
(654.34). ES-MS (positive mode, m/z) found): 655.4 (M+H), 677.4
(M+Na).
Example 25
Preparation of Compound 36
The mixture of 25 (140 mg, 0.225 mmol), 35 (100 mg, 0.153 mmol) and
tetrazole (20 mg) in dry DCM (7 mL) was stirred at room temperature
for 3 h. 2-Butanone peroxide solution (1.0 M in DCM, 2.0 mL, 2.0
mmol) was added and the mixture was stirred for 10 min. The
solution was then diluted with DCM (100 mL) and the organic layer
washed successively with 10% NaHCO.sub.3 (aq.) (20 mL) and brine
(20 mL), dried over sodium sulfate and concentrated. The residue
was purified by flash chromatography (ethyl
acetate/hexane/DCM/methanol, 5:2:2:1) to give 36 (117 mg, 64%).
TLC: R.sub.f=0.34 (DCM/methanol, 9:1).
C.sub.55H.sub.74N.sub.10O.sub.16P.sub.2 (1192.47). ES-MS (positive
mode, m/z) found: 1193.5 (M+H), 1215.5 (M+Na). .sup.1H NMR (600
MHz, CDCl.sub.3): .delta. 0.86 (t, J=7.5 Hz, 3 H, CH.sub.3) 1.25
(m, 28 H, 11 CH.sub.2, 2 CH.sub.3), 1.65 (m, 2 H), 2.75 (m, 5H),
3.30 (m, 2 H), 4.10-4.60 (m, 14 H), 5.44 (m, 1 H), 5.58 (m, 1 H),
5.82 (m, 2 H), 5.88 (m, 2 H), 7.38-8.20 (m, 13 H), 9.40 (br s, 1 H,
NH), 12.20 (br s, 1 H, NH).
Example 26
Preparation of Compound 6
Compound 36 was dissolved in ethanol (2.0 mL) and conc. ammonium
hydroxide (58%, 4.0 mL) was added. The mixture was stirred at
55.degree. C. for 24 h and then concentrated in vacuo. The residue
was re-dissolved in water (8.0 mL) and filtered through 0.22 .mu.m
filter and the clear solution was lyophilized to give the crude
product (80 mg) which was further purified by HPLC to give 6 (41.3
mg, 61%). (HPLC condition was given in Example 3, as that described
for the purification of compound 1-5). TLC: R.sub.f=0.16
(chloroform/methanol/water/conc. ammonium hydroxide, 5:3:0.5:0.5).
C.sub.31H.sub.54N.sub.8O.sub.13P.sub.2 (808.33). ES-MS (positive
mode, m/z) found: 831 (M+Na), 853 (M+2Na--H), 875 (M+3Na-2 H), 897
(M+4Na-3 H). .sup.1H NMR (500 MHz, DMSO-d.sub.6): .delta. 0.85 (t,
J=7.0 Hz, 3 H, CH.sub.3), 1.22 (br s, 22 H, 11 CH.sub.2), 1.41 (m,
2 H), 3.39 (m, 2 H), 3.52-3.72 (m, 9 H), 3.94 (m, 1 H), 5.12 (d,
J=10.0 Hz, 1 H), 5.16 (d, J=10.0 Hz, 1 H), 5.68 (s, 2 H), 5.75 (d,
J=7.5 Hz, 1 H), 6.25 (br s, 2 H), 7.12 (s, 1 H), 7.48 (s, 1 H),
7.68 (d, J=7.5 Hz, 1 H), 8.11 (s, 1 H).
Example 27
Preparation of Compound 7
The hybrid structure of peptide and peptide nucleic acid was
prepared using peptide synthesizer by employing the technique of
standard solid phase peptide synthesis. Wang resin was chosen as
the solid support using Fmoc/Bhoc chemistry. The reaction scheme
and reaction conditions are described in FIG. 15. after the
cleavage from the resin, the product was purified by HPLC and the
structure confirmed by ES-MS spectroscopic data.
Compound 7: C.sub.44H.sub.72N.sub.14O.sub.10 (956.55). ES-MS
(positive mode, m/z) found: 957.5 (M+H), 979.5 (M+Na), 1001.5
(M+2Na--H), 1023.5 (M+3Nz-2 H), 1045.5 (M+4Nz-3 H).
Example 28
Preparation of BLP25 Liposomal Vaccine
Typically, the liposomal formulation was composed of 400 .mu.g of
MUC1-based lipopeptide BP1-148 (FIG. 17),
H.sub.2N-STAPPAHGVTSAPDTRPAPGSTAPPK(Pal)G-OH, 200 .mu.g of CpG
analog 1-6, 6.94 mg of cholesterol, 1.46 mg of dimyristoyl
phosphatidylglycerol (DMPC) and 11.62 mg of dipalmitoyl
phosphatidylcholine (DPPC) per 1 ml of saline (0.9% NaCl
solution).
The liposomal constructs were formulated by first dissolving the
phospholipids, cholesterol and CpG analog 1-6 in tert-butanol at
about 53.degree. C. Lipopeptide and water (5%, v/v) were then added
to the tert-butanol solution. The resulting clear 95% tert-butanol
solution was injected into about 4 volumes of rapidly stirred water
at about 50.degree. C., using a glass syringe with an 18-gauge
needle. The small unilamellar vesicles (SUV) formed in this process
were cooled, sterilized by filtration through a 0.22 .mu.m membrane
filter, filled into vials and lyophilized. The dry powder was
re-hydrated with sterile saline before injection, resulting in the
formation of multilamellar large vesicles (MLV). The liposomes
formed are used to immunize mice.
Example 29
Mice Immunized with Liposomal Vaccines
Groups of C57-Black mice were immunized subcutaneously with the
BLP25 liposomal vaccine containing 400 .mu.g of MUC1-based
lipopeptide BP1-148 (FIG. 17), and 200 .mu.g of CpG analog per
dose. Nine days after vaccine injection mice were sacrificed and
lymphocytes were taken from the draining lymph nodes (local
response) or from the spleens (systemic response) to determine the
immune response in each group. The lymphocytes taken from immunized
mice were incubated in in vitro cultures in the presence of
MUC1-based boosting antigen BP1-151, which has the peptide sequence
H.sub.2N-STAPPAHGVTSAPDTRPAPGSTAPPK-OH (SEQ ID NO:11) This sequence
corresponds to SEQ ID NO:2 plus a terminal lysine.
Example 30
Measurement of T-cell Proliferation
T-cell proliferation is evaluated using a standard .sup.3H
thymidine incorporation assay. Briefly, nylon wool passed inguinal
lymph node lymphocytes, at 0.25.times.10.sup.6/well, pooled from
each mouse group, are added to a culture containing naive mitomycin
C-treated syngeneic splenocytes at 0.25.times.10.sup.6/well, which
serve as antigen presenting cells (APCs). To each well 20 .mu.g of
MUC1-based 25-mer peptide is added as boosting antigen. The culture
is incubated for 72 h in a total volume of 300 .mu.L/well, followed
by the addition of 1 .mu.Ci of .sup.3H-thymidine in a volume of 50
.mu.L. The plates are incubated for an additional 18-20 h. Cells
are harvested and [.sup.3H]dTh incorporation is measured by liquid
scintillation counter. T-cell proliferation results corresponding
to various liposomal vaccines adjuvanted with 1-6 or the reference
natural R595 lipid A are shown in FIG. 16.
R595 lipid A is the natural detoxified lipid A product isolated
from the bacteria Salmonella minnesota, R595. This material is
commercially available from Avanti Polar Lipids, Inc., USA. R595
lipid A is a strong vaccine adjuvant currently under clinical
investigation for human use, and therefore it is chosen here as a
reference to compare the immune stimulatory (adjuvant) properties
of compound 1-6.
As shown in FIG. 16, compound 1-6 demonstrate strong immunoadjuvant
activity in enhancing antigen specific T cell proliferation. All
these CpG analogues show the same or higher magnitude of activity
compared to R595 lipid A. Compound 3-6 demonstrate obviously
stronger activity then R595 lipid A. Interestingly, the
glycerol-based CpG analogue 6 has stronger activity than compound 1
and 2 which are based on natural DNA backbone. Collectively, these
data show that short oligonucleotide sequence (as small as
dinucleotide) and their structural mimics containing unmethylated
CpG unit, when modified with strong lipophilic group(s), has strong
immune stimulatory properties.
The biological activity of compound 7 has not been evaluated.
REFERENCES
Akira, S., Takeda, K. & Kaisho, T. Nature Immunol. 2001, 2,
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Takeuchi, O. et al, Immunity, 1999, 11, 443-451. Uhlmann, E. &
Peyman, A. Chem. Rev. 1990, 90, 543-586. Zamecnik, P. C. &
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280-284.
Citation of documents herein is not intended as an admission that
any of the documents cited herein is pertinent prior art, or an
admission that the cited documents is considered material to the
patentability of any of the claims of the present application. All
statements as to the date or representation as to the contents of
these documents is based on the information available to the
applicant and does not constitute any admission as to the
correctness of the dates or contents of these documents.
The appended claims are to be treated as a non-limiting recitation
of preferred embodiments.
In addition to those set forth elsewhere, the following references
are hereby incorporated by reference, in their most recent editions
as of the time of filing of this application: Kay, Phage Display of
Peptides and Proteins: A Laboratory Manual; the John Wiley and Sons
Current Protocols series, including Ausubel, Current Protocols in
Molecular Biology; Coligan, Current Protocols in Protein Science;
Coligan, Current Protocols in Immunology; Current Protocols in
Human Genetics; Current Protocols in Cytometry; Current Protocols
in Pharmacology; Current Protocols in Neuroscience; Current
Protocols in Cell Biology; Current Protocols in Toxicology; Current
Protocols in Field Analytical Chemistry; Current Protocols in
Nucleic Acid Chemistry; and Current Protocols in Human Genetics;
and the following Cold Spring Harbor Laboratory publications:
Sambrook, Molecular Cloning: A Laboratory Manual; Harlow,
Antibodies: A Laboratory Manual; Manipulating the Mouse Embryo: A
Laboratory Manual; Methods in Yeast Genetics: A Cold Spring Harbor
Laboratory Course Manual; Drosophila Protocols; imaging Neurons: A
Laboratory Manual; Early Development of Xenopus laevis: A
Laboratory Manual; Using Antibodies: A Laboratory Manual; At the
Bench: A Laboratory Navigator; Cells: A Laboratory Manual; Methods
in Yeast Genetics: A Laboratory Course Manual; Discovering Neurons:
The Experimental Basis of Neuroscience; Genome Analysis: A
Laboratory Manual Series; Laboratory DNA Science; Strategies for
Protein Purification and Characterization: A Laboratory Course
Manual; Genetic Analysis of Pathogenic Bacteria: A Laboratory
Manual; PCR Primer: A Laboratory Manual; Methods in Plant Molecular
Biology: A Laboratory Course Manual; Manipulating the Mouse Embryo:
A Laboratory Manual; Molecular Probes of the Nervous System;
Experiments with Fission Yeast: A Laboratory Course Manual; A Short
Course in Bacterial Genetics: A Laboratory Manual and Handbook for
Escherichia coli and Related Bacteria; DNA Science: A First Course
in Recombinant DNA Technology; Methods in Yeast Genetics: A
Laboratory Course Manual; Molecular Biology of Plants: A Laboratory
Course Manual.
All references cited herein, including journal articles or
abstracts, published, corresponding, prior or otherwise related
U.S. or foreign patent applications, issued U.S. or foreign
patents, or any other references, are entirely incorporated by
reference herein, including all data, tables, figures, and text
presented in the cited references. Additionally, the entire
contents of the references cited within the references cited herein
are also entirely incorporated by reference.
Reference to known method steps, conventional methods steps, known
methods or conventional methods is not in any way an admission that
any aspect, description or embodiment of the present invention is
disclosed, taught or suggested in the relevant art.
The foregoing description of the specific embodiments will so fully
reveal the general nature of the invention that others can, by
applying knowledge within the skill of the art (including the
contents of the references cited herein), readily modify and/or
adapt for various applications such specific embodiments, without
undue experimentation, without departing from the general concept
of the present invention. Therefore, such adaptations and
modifications are intended to be within the meaning and range of
equivalents of the disclosed embodiments, based on the teaching and
guidance presented herein. It is to be understood that the
phraseology or terminology herein is for the purpose of description
and not of limitation, such that the terminology or phraseology of
the present specification is to be interpreted by the skilled
artisan in light of the teachings and guidance presented herein, in
combination with the knowledge of one of ordinary skill in the
art.
Any description of a class or range as being useful or preferred in
the practice of the invention shall be deemed a description of any
subclass (e.g., a disclosed class with one or more disclosed
members omitted) or subrange contained therein, as well as a
separate description of each individual member or value in said
class or range.
The description of preferred embodiments individually shall be
deemed a description of any possible combination of such preferred
embodiments, except for combinations which are impossible (e.g,
mutually exclusive choices for an element of the invention) or
which are expressly excluded by this specification.
If an embodiment of this invention is disclosed in the prior art,
the description of the invention shall be deemed to include the
invention as herein disclosed with such embodiment excised.
The invention, as contemplated by applicant(s), includes but is not
limited to the subject matter set forth in the appended claims, and
presently unclaimed combinations thereof. It further includes such
subject matter further limited, if not already such, to that which
overcomes one or more of the disclosed deficiencies in the prior
art. To the extent that any claims encroach on subject matter
disclosed or suggested by the prior art, applicant(s) contemplate
the invention(s) corresponding to such claims with the encroaching
subject matter excised.
All references, including patents, patent applications, books,
articles, and online sources, cited anywhere in this specification
are hereby incorporated by reference, as are any references cited
by said references.
SEQUENCE LISTINGS
1
12110DNAArtificial SequenceSynthesizable sequence, corresponds to
128H described in Cheng et al. USP 5,646,126 1cacacgtgtg
10225PRTArtificial SequenceSynthesized peptide shown in Fig. 17
BP1-148 2Ser Thr Ala Pro Pro Ala His Gly Val Thr Ser Ala Pro Asp
Thr Arg1 5 10 15Pro Ala Pro Gly Ser Thr Ala Pro Pro 20
25320DNAArtificial SequenceSynthesizable activating sequence, shown
in Fig. 1 3ggtgcatcga tgcagggggg 20410PRTLeishmani major 4Glu Ala
Glu Glu Ala Ala Arg Leu Gln Ala1 5 10525PRTArtificial SequenceMUC1
repeat consensus sequence 5Pro Ala Pro Gly Ser Thr Ala Pro Pro Ala
Gln Thr Ala His Gly Val1 5 10 15Thr Ser Ala Pro Asp Glu Thr Ser Arg
20 25612PRTArtificial SequenceMUC1 fragment 6Pro Gly Ser Thr Ala
Pro Pro Ala His Gly Val Thr1 5 1079PRTArtificial SequenceMUC1
fragment 7Thr Leu Ala Pro Ala Thr Glu Pro Ala1 589PRTArtificial
SequenceMUC1 fragment 8Ala Leu Gly Ser Thr Ala Pro Pro Val1
599PRTArtificial SequenceMUC1 fragment 9Phe Leu Ser Phe His Ile Ser
Asn Leu1 51020PRTArtificial SequenceMUC1 repeat 10Gly Val Thr Ser
Ala Pro Asp Thr Arg Pro Ala Pro Gly Ser Thr Ala1 5 10 15Pro Pro Ala
His 201128PRTArtificial SequenceSynthesized peptide shown in Fig.
17 as intermediate 11Ser Thr Ala Pro Pro Ala His Gly Val Thr Ser
Ala Pro Pro Asp Thr1 5 10 15Arg Pro Ala Pro Gly Ser Thr Ala Pro Pro
Lys Gly 20 251212PRTPlasmodium falciparum 12Asn Ala Asn Pro Asn Ala
Asn Pro Asn Ala Asn Pro1 5 10
* * * * *
References