U.S. patent application number 14/160436 was filed with the patent office on 2014-07-03 for epitope peptides derived from vascular endothelial growth factor receptor 1 and vaccines containing these peptides.
This patent application is currently assigned to Oncotherapy Science, Inc.. The applicant listed for this patent is Oncotherapy Science, Inc.. Invention is credited to Shuichi Nakatsuru, Masabumi Shibuya, Hideaki Tahara, Takuya Tsunoda.
Application Number | 20140186381 14/160436 |
Document ID | / |
Family ID | 36581423 |
Filed Date | 2014-07-03 |
United States Patent
Application |
20140186381 |
Kind Code |
A1 |
Tahara; Hideaki ; et
al. |
July 3, 2014 |
EPITOPE PEPTIDES DERIVED FROM VASCULAR ENDOTHELIAL GROWTH FACTOR
RECEPTOR 1 AND VACCINES CONTAINING THESE PEPTIDES
Abstract
The present invention provides immunogenic peptides comprising
the amino acid sequence of SEQ ID NO: 1, 2, 13, 32, and peptides
comprising the above-mentioned amino acid sequences in which 1, 2,
or several amino acids are substituted or added, and having
cytotoxic T cell inducibility, and also provides drugs for treating
or preventing tumors comprising these peptides. The peptides of
this invention can be used as vaccines.
Inventors: |
Tahara; Hideaki; (Tokyo,
JP) ; Tsunoda; Takuya; (Tokyo, JP) ; Shibuya;
Masabumi; (Tokyo, JP) ; Nakatsuru; Shuichi;
(Kanagawa, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Oncotherapy Science, Inc. |
Kanagawa |
|
JP |
|
|
Assignee: |
Oncotherapy Science, Inc.
Kanagawa
JP
|
Family ID: |
36581423 |
Appl. No.: |
14/160436 |
Filed: |
January 21, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13566933 |
Aug 3, 2012 |
8663647 |
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14160436 |
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13040177 |
Mar 3, 2011 |
8257711 |
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13566933 |
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11816893 |
Mar 6, 2009 |
7919099 |
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PCT/JP2006/303352 |
Feb 17, 2006 |
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13040177 |
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60657527 |
Feb 28, 2005 |
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Current U.S.
Class: |
424/185.1 |
Current CPC
Class: |
A61K 38/00 20130101;
A61P 3/10 20180101; A61P 35/00 20180101; A61P 43/00 20180101; A61P
37/04 20180101; A61P 9/10 20180101; A61P 19/02 20180101; A61P 9/00
20180101; A61P 35/04 20180101; A61P 29/00 20180101; A61P 27/02
20180101; A61P 17/06 20180101; A61K 39/00 20130101; C07K 14/71
20130101 |
Class at
Publication: |
424/185.1 |
International
Class: |
A61K 39/00 20060101
A61K039/00 |
Claims
1. A method of treating angiogenesis-mediated disease in a subject
comprising administering to the subject a composition comprising a
peptide selected from the group consisting of: (a) an isolated
peptide consisting of the amino acid sequence of SEQ ID NO: 1, (b)
an isolated peptide having cytotoxic T cell inducibility, wherein
the peptide consists of the amino acid sequence of SEQ ID NO: 1, in
which 1 or 2 amino acids are substituted, and wherein the second
amino acid from the N terminus is leucine or methionine, and the
C-terminal amino acid is valine or leucine.
2. The method of claim 1, wherein the angiogenesis-mediated disease
is selected from the group consisting of diabetic retinopathy,
chronic rheumatoid arthritis, psoriasis, and atherosclerosis.
3. A method of inhibiting angiogenesis at a diseased site in a
subject comprising administering to the subject a composition
comprising a peptide selected from the group consisting of: (a) an
isolated peptide consisting of the amino acid sequence of SEQ ID
NO: 1, (b) an isolated peptide having cytotoxic T cell
inducibility, wherein the peptide consists of the amino acid
sequence of SEQ ID NO: 1, in which 1 or 2 amino acids are
substituted, and wherein the second amino acid from the N terminus
is leucine or methionine, and the C-terminal amino acid is valine
or leucine, as the active ingredient.
4. The method of claim 3, wherein the subject expresses
HLA-A02.
5. The method of claim 3, wherein the diseased site comprises a
malignant tumor or metastasis of a malignant tumor.
6. The method of claim 3, wherein the diseased site comprises
VEGFR1 expressing cells.
Description
[0001] This application is a continuation of U.S. application Ser.
No. 13/566,933, filed Aug. 3, 2012, which is a division of U.S.
application Ser. No. 13/040,177, filed Mar. 3, 2011, now U.S. Pat.
No. 8,257,711, which is a division of U.S. application Ser. No.
11/816,893, filed Mar. 6, 2009, now U.S. Pat. No. 7,919,099, which
is a U.S. National Stage Application of PCT/JP2006/303352, filed
Feb. 17, 2006, which claims the benefit of U.S. Provisional
Application Ser. No. 60/657,527 filed Feb. 28, 2005, all of which
are hereby incorporated by reference in their entirety.
REFERENCE TO SEQUENCE LISTING
[0002] This application includes a Sequence Listing as a text file
named "87331-002240US-8896777_SEQLIST.txt" created Jan. 2, 2014,
and containing 31,372 bytes. The material contained in this text
file is incorporated by reference in its entirety for all
purposes.
FIELD OF THE INVENTION
[0003] The present invention relates to peptides that are extremely
effective as cancer vaccines, and drugs for treating and preventing
tumors, which contain these peptides.
BACKGROUND OF THE INVENTION
[0004] Tumor growth is generally limited to 1.about.2 mm.sup.3 in
the absence of a vascularized blood supply, and angiogenesis has a
critical role in the invasion, growth and metastasis of tumors
(Folkman, J. (2002) Semin. Oncol. 29: 15-8., Folkman, J. (1996)
Nat. Med. 2: 167-8., Kerbel and Folkma, (2002). Nature Rev. Cancer.
2: 727-39., Brown et al., (1995) Hum. Pathol. 26: 86-91., Eberhard
et al., (2000) Cancer Res. 60: 1388-93.). It has been also shown
that inhibition of tumor angiogenesis is associated with
suppression of tumor progression. In order to achieve suppression
of angiogenesis, a number of investigators have been examining
therapeutic strategies targeting vascular endothelial growth factor
(VEGF) and VEGF receptor (VEGFR), which play critical roles in
regulating the process of angiogenesis. These studies have shown
that tumor growth can be successfully suppressed in vitro and in
vivo using monoclonal antibodies, recombinant receptors or
inhibitors for signal transduction (El-Mousawi et al., (2003) J.
Biol. Chem. 278: 46681-91., Stefanik et al., (2001) J. Neurooncol.
55: 91-100., Wood et al., (2000) Cancer Res. 60: 2178-89., Luttun
et al., (2002) Nat. Med. 8: 831-40., Lyden et al., (2001) Nat. Med.
7: 1194-201., Lu et al., (2001) Cancer Res. 61: 7002-8.). However,
these strategies require frequent or continuous administration of
the reagents at relatively high dose levels, which may be
associated with significant inconvenience and adverse effects.
[0005] VEGF binds two related tyrosine kinase receptors, VEGFR1
(Flt-1) and VEGFR2 (KDR), which are strongly expressed on
endothelial cells in tumor tissue but not in normal tissue (Risau,
W. (1997) Nature. 386: 671-4., Ferrara and Davis-Smyth, (1997)
Endor. Rev. 18: 4-25., Shibuya et al., (1999) Curr. Topics.
Microbiol. Immunol. 237: 59-83., Plate et al., (1994) Int. J.
Cancer. 59: 520-9.). VEGFR1 is the first VEGF receptor to be
identified (Shibuya et al., (1990) Oncogene 5: 519-24.), and it
interacts with VEGF (VEGF-A) and with two other members of VEGF
family, VEGF-B (Olofsson et al., (1996) Proc. Natl. Acad. Sci. USA
93: 2576-81.) and placenta growth factor (PlGF) (Maglione et al.,
1991. Proc. Natl. Acad. Sci. USA 88: 9267-71.). By displacing VEGF
from VEGFR1, PlGF is expected to make more VEGF available to bind
and activate VEGFR2 and thereby enhance VEGF-driven angiogenesis
(Park et al., (1994) J. Biol. Chem. 269: 25646-54.). Other studies
have shown that a synergism exists between VEGF and PlGF in vivo,
especially during pathological situations, as evidenced by impaired
tumorigenesis and vascular leakage in PlGF-/- mice (Carmeliet et
al., (2001) Nat. Med. 7: 575-83.).
[0006] Recent reports have shown that vaccination using cDNA or
recombinant protein of mouse VEGFR2 is associated with significant
anti-tumor effects in mouse tumor models (Li et al., (2002) J. Exp.
Med. 195: 1575-84., Niethammer et al., (2002) Nat. Med. 8:
1369-75.). But these results cannot directly warrant clinical
application of this strategy, since they used the mouse homologue
of human VEGFR2 in mouse systems that are considered to be
significantly different from the human counterpart.
Abbreviations Used in the Present Application:
[0007] CTL, cytotoxic T lymphocyte VEGF, vascular endothelial
growth factor PlGF, placenta growth factor VEGFR1, vascular
endothelial growth factor receptor 1 VEGFR2, vascular endothelial
growth factor receptor 2 TGM, transgenic mice TAA, tumor associate
antigen. i.d., intradermal injection s.c., subcutaneous injection
IFA, incomplete FREUND's adjuvant
BRIEF SUMMARY OF THE INVENTION
[0008] The present invention provides peptides that induce
cytotoxic T cells against endothelial cells endogenously expressing
VEGFR1. The peptides of the invention comprise an amino acid
sequence of SEQ ID NO: 1, 2, 13 or a sequence wherein 1, 2, or
several amino acids are substituted or added. In certain
embodiments, the second amino acid from the N terminus is leucine
or methionine. In some embodiments, the C-terminal amino acid is
valine or leucine.
[0009] The present invention also provides peptides comprising the
amino acid sequence of SEQ ID NO: 32, or a sequence wherein 1, 2,
or several amino acids are substituted or added. In certain
embodiments, the second amino acid from the N terminus is
phenylalanine, tyrosine, methionine, or tryptophan. In some
embodiments, the C-terminal amino acid is phenylalanine, leucine,
isoleucine, tryptophan, or methionine.
[0010] The present invention further provides pharmaceutical
compositions for treating or preventing tumors, wherein the
composition comprises the peptides of the invention.
[0011] The present invention provides exosomes that present on
their surface a complex comprising the peptide of this invention
and an HLA antigen. In some embodiments, the HLA antigen is HLA-A24
(e.g., HLA A2402) or HLA-A02 (HLA-0201).
[0012] Methods of inducing antigen-presenting cells having high
cytotoxic T cell inducibility and methods of inducing cytoxic T
cells comprising administering the peptides of the invention to a
patient are also provided. In some embodiments, the methods
comprise transferring a gene comprising a polynucleotide encoding
the peptide of the invention to antigen-presenting cells. The
invention provided isolated cytotoxic T cells and antigen
presenting cells which are induced by the methods of the invention.
The present invention provides antigen-presenting cells, which
comprise a complex formed between an HLA antigen and the peptide of
the invention.
[0013] The present invention also provides vaccines for inhibiting
angiogenesis at a diseased site, wherein the vaccine comprises the
peptide of the invention as the active ingredient. The vaccine of
the invention may be intended for administration to a subject whose
HLA antigen is HLA-A24 or HLA-A02. In some embodiments, the vaccine
is used to suppress the growth of and/or metastasis of malignant
tumors.
[0014] The present invention further provides methods of treating
or preventing tumors in a subject comprising administering to said
subject a vaccine comprising a peptide of the invention, or an
immunologically active fragment, or a polynucleotide encoding the
peptide.
[0015] The invention also provides methods of treating or
preventing angiogenesis-mediated disease in a subject comprising
administering a vaccine of the invention. In some embodiments, the
angiogenesis-mediated disease is diabetic retinopathy, chronic
rheumatoid arthritis, psoriasis, or atherosclerosis.
[0016] It is to be understood that both the foregoing summary of
the invention and the following detailed description are of a
preferred embodiment, and not restrictive of the invention or other
alternate embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a graph showing the establishment of HLA-A*0201
restricted CTL clones using epitope candidates derived from VEGFR1.
Cytotoxicity of each CTL clone against T2 cells pulsed each epitope
peptide binding with HLA-A*0201. T2 cells were used for CTL
responses in the presence or absence of each peptide. CTL clones
showed specific cytotoxicities against the target cells pulsed with
corresponding peptides. E/T ratio indicates
effector/target-cell.
[0018] FIG. 2 is a graph showing the establishment of HLA-A*2402
restricted CTL clones using epitope candidates derived from VEGFR1.
A24-LCL cells were used for CTL responses restricted to HLA-A*2402
in the presence or absence of each peptides binding with
HLA-A*2402. CTL clones showed specific cytotoxicities against the
target cells pulsed with corresponding peptides. E/T ratio
indicates effector/target-cell.
[0019] FIG. 3 is a graph showing the cytotoxicity against
endogeneously VEGFR1 expressing cells. HLA-A*2402 CTL clone was
examined for the cytotoxicity against VEGFR1 expressing cells
(AG1-G1-Flt-1) and control (AG1-G1) with a 4-hr .sup.51Cr-release
assay. These CTL clones showed the cytotoxicities against
AG1-G1-Flt-1, but not against AG1-G1. E/T ratio indicates
effector/target-cell.
[0020] FIG. 4 is a graph showing the results of in vivo CTL
response associated with the vaccination using VEGFR1-epitope
peptides by IFN-.gamma. ELISPOT assay. IFA-conjugated peptides were
injected i.d. into A2/Kb TGM on day 0 and day 11. On day 21,
splenocytes of the vaccinated mice were used as the responder
cells, and T2 cells pulsed with or without peptides were used as
the stimulator cells for ELISPOT assay. Specific production of
IFN-.gamma. for the corresponding peptide was observed in the mice
vaccinated with VEGFR1-1087, -770, -417 peptides. (E/T ratio:
x20).
[0021] FIG. 5 is a graph showing the results of in vivo inhibition
of tumor-induced angiogenesis. The angiogenic responses induced by
MC38 cells in A2/Kb TGM. The mice were vaccinated twice with HBSS,
IFA alone, and VEGFR1-peptide conjugated with IFA (VEGFR1-1087,
-770, -417). Differences were visible macroscopically in the
implanted chambers removed from s.c. fascia of vaccinated mice.
Quantification of newly formed vessels in the angiogenic response.
Significant inhibition of tumor-induced angiogenesis was observed
in mice vaccinated with VEGFR1-1087, -770, -417 peptides. Error bar
indicate s.e.
[0022] FIG. 6 is a graph showing the results of in vivo anti-tumor
effect. A2/Kb TGM was inoculated i.d. with MCA205 cells. HBSS, IFA
only, and IFA conjugated with VEGFR1-1087, -770, -417 peptides were
vaccinated 4 days and 11 days later (the indicated arrow).
Significant suppression of tumor growth was observed with the
vaccination using VEGFR1-1087, -770 peptides conjugated with
IFA.
DETAILED DESCRIPTION OF THE INVENTION
[0023] The words "a", "an", and "the" as used herein mean "at least
one" unless otherwise specifically indicated.
[0024] Angiogenesis has been shown to be a critical mechanism for
tumor progression. Multiple studies have suggested that tumor
growth can be suppressed if tumor angiogenesis can be inhibited
using various types of anti-angiogenic agents. In the present
invention, we examined the possibility of developing novel
immunotherapy targeting VEGFR1. We first identified the peptide
epitopes of VEGFR1 from HLA-A2 and A24, and successfully
established CTL clones with potent cytotoxicity against endothelial
cells endogenously expressing VEGFR1. In A2/Kb transgenic mice,
vaccination using these epitope peptides in vivo was associated
with significant suppression of tumor growth in a therapeutic
model. In anti-angiogenesis assay, tumor-induced angiogenesis was
significantly suppressed with the vaccination. These results in
vitro and in vivo strongly suggest VEGFR1 could be a promising
target, and support the definitive rationale of the clinical
development for anti-angiogenic immunotherapy against various kinds
of cancers.
[0025] In the present invention, we examined the effectiveness of
this novel immunotherapy in systems closely related to clinical
settings. We identified the epitope peptides of human VEGFR1
restricted to HLA-A*0201 and A*2402 (Rammensee et al., 1995.
Immunogenetics. 41: 178-228.) and showed that CTLs induced with
these peptides have potent and specific cytotoxicity against not
only peptide-pulsed target cells but also target cells endogenously
expressing VEGFR1 in an HLA class I restricted fashion.
Furthermore, we examined in vivo anti-tumor effects of the
vaccination with these epitope peptides using a unique mouse model
that may be directly translated into the clinical setting. Our
model system uses A2/Kb transgenic mice (TGM), which have been
shown to be useful for the analysis of human CTL epitopes. There is
approximately 71% concordance between humans and A2/Kb TGM in the
CTL repertoire (Wentworth et al., (1996) Eur. J. Immunol. 26:
97-101.). To construct tumor systems, we transplanted syngeneic
mouse tumor cells which were chemically induced in C57BL/6 mice
(H-2 Kb) not expressing HLA-A*0201 molecules. This tumor system,
combining A2/Kb TGM and H-2 Kb mouse cell line, offers a unique
setting. Since endothelial cells in A2/Kb TGM express HLA-A*0201
molecule, the CTLs induced by vaccination using VEGFR1 epitope
peptides recognize endothelial cells which express both HLA-A*0201
and VEGFR1. Thus, in vivo anti-tumor effects of an anti-angiogenic
vaccine can be evaluated in HLA-A*0201 restricted fashion. However,
they do not recognize tumor cells even if they express VEGFR1
because they do not express HLA-A*0201. In this in vivo tumor
model, vaccination using these epitope peptides was associated with
significant suppression of the tumor growth. In an
anti-angiogenesis assay, tumor-induced angiogenesis was
significantly suppressed with vaccination using these epitope
peptides. These results show that the vaccination using epitope
peptides derived from VEGFR1 induces an antitumor-immune
response.
[0026] Identification of the tumor associate antigens (TAAs) has
enabled the clinical development of peptide-based cancer vaccines,
which could induce CTLs and lyse tumor cells in HLA class I
restricted fashion (Bruggen et al., (1991) Science. 254: 1643-7.,
Boon et al., (1996) J. Exp. Med. 183: 725-9., Rosenberg et al.,
(1998) Nat. Med. 4: 321-7., Butterfield et al., (1999) Cancer Res.
59: 3134-42.). Multiple clinical trials using TAA peptides have
reported that tumor regressions were observed in the melanoma
patients (Rosenberg et al., (1998) Nat. Med. 4: 321-7. Nestle et
al., (1998) Nat. Med. 4: 328-32., Thurner et al., (1999) J. Exp.
Med. 190: 1669-78., Belli et al., (2002) J. Clin. Oncol. 20:
4169-80., Coulie et al., (2002) Immunol. Rev. 188: 33-42.). It has
been suggested that clinical efficacy could be effected by loss or
down-regulation of HLA class I molecules on the tumor cells
(Cormier et al., (1998) Int. J. Cancer. 75: 517-24., Paschen et
al., (2003) Int. J. Cancer. 103: 759-67., Fonteneau et al., (1997)
J. Immuol. 159: 2831-9. Reynolds et al., (1998) J. Immunol. 161:
6970-6.). The frequency of tumors showing some alteration in
expression of HLA class I molecules has been estimated to be more
than 40% (Cormier et al., (1998) Int. J. Cancer. 75: 517-24.,
Paschen et al., (2003) Int. J. Cancer. 103: 759-67.). Thus,
significant portion of tumor cells could escape from the CTLs
specific to the class I-epitope, even if CTLs could be successfully
induced by cancer vaccine targeting tumor cells themselves. The
development of effective vaccines against endothelial cells
involved in tumor angiogenesis is an alternate approach.
Endothelial cells are genetically stable, do not show
down-regulation of HLA Class I molecules, and are critically
involved in the progression of a variety of tumor. Furthermore, the
CTLs could directly cause damage to the endothelial cells without
penetrating any other tissue, and lysis of even low numbers of
endothelial cells within tumor vasculature may result in
destruction of vessel integrity leading to inhibition of large
numbers of tumor cells (Folkman, J. (1995) Nat. Med. 1: 27-31.).
Therefore, endothelial cells are a good target for cancer
immunotherapy. To specifically and efficiently prevent
tumor-angiogenesis with CTL response, the appropriate target needs
to be selected among the molecules related to angiogenesis.
[0027] VEGF binds two related tyrosine kinase receptors, VEGFR1
(Flt-1) (SEQ ID NOS:44 and 45) and VEGFR2 (KDR), which are strongly
expressed on endothelial cells in tumor tissue but not in normal
tissue (Risau, W. (1997) Nature. 386: 671-4., Shibuya et al.,
(1999) Curr. Topics. Microbiol. Immunol. 237: 59-83., Plate et al.,
(1994) Int. J. Cancer. 59: 520-9.). Suppression of these receptors
showed anti-tumor effects including neutralizing antibody,
recombinant receptors or kinase inhibitors (El-Mousawi et al.,
(2003) J. Biol. Chem. 278: 46681-91., Stefanik et al., (2001) J.
Neurooncol. 55: 91-100., Wood et al., (2000) Cancer Res. 60:
2178-89., Luttun et al., (2002) Nat. Med. 8: 831-40., Lyden et al.,
(2001) Nat. Med. 7: 1194-201., Lu et al., (2001) Cancer Res. 61:
7002-8.). Neutralizing anti-VEGFR1 antibodies efficiently
attenuated tumor growth and neovascularization with dose dependent
manner (Luttun et al., (2002) Nat. Med. 8: 831-40.). Furthermore,
combination treatment with reagents blocking both VEGFR1 and VEGFR2
or the use of a bifunctional antibody (`diabody`) against VEGFR1
and VEGFR2, as such strategies resulted in stronger inhibition of
vessel growth than monotherapy with a single antibody or with the
monofunctional parent antibody (Lyden et al., (2001) Nat. Med. 7:
1194-201., Lu et al., (2001) Cancer Res. 61: 7002-8.).
[0028] In the present invention using our novel model systems in
vitro and in vivo, we have demonstrated that an immunotherapy
targeting tumor-induced angiogenesis is effective. At first, we
identified the epitope peptides of VEGFR1 restricted to HLA-A*0201
and A*2402 which are frequently recognized HLA-alleles (Rammensee
et al., (1995) Immunogenetics. 41: 178-228.). The CTLs were
successfully induced with these peptides, and they showed potent
cytotoxic activities against not only peptide-pulsed target cells
but also endogenously VEGFR1 expressing cells. Our findings clearly
demonstrated that human VEGFR1 is immunogenic in the human
system.
[0029] Then, we demonstrated in vivo anti-tumor effects using
multiple tumor cell lines and A2/Kb TGM, a good model system to
evaluate immune responses in humans against tumor cells with the
loss of HLA class I expression. It has been shown that there is
approximately 71% concordance between the CTL repertoire of human
and A2/Kb TGM (Wentworth et al., (1996) Eur. J. Immunol. 26:
97-101.). Thus, CTLs induced by vaccination using epitope peptides
could recognize endothelial cells, which are derived from A2/Kb TGM
and express VEGFR1 and HLA-A*0201, but do not recognize the tumor
cells which have no "human" MHC class I molecules. Using this
unique tumor model system, significant inhibition of the tumor
growth was observed with vaccination using these epitope peptides.
This peptide-based vaccine was also associated with significant
suppression of tumors before the vaccination as well. These results
show that our vaccination strategy is effective even for tumors
with HLA deficit, which is considered to be one of the escape
mechanisms of tumors. We have also shown in a DAS assay that
tumor-induced angiogenesis was significantly inhibited with
vaccination using these epitope peptides. This result shows that
the inhibition of tumor angiogenesis can be achieved with peptide
vaccination targeting the molecule expressed on tumor-induced
vascular endothelial cells.
[0030] These results, in vitro and in vivo, show that VEGFR1 is a
useful target of immunological therapy using cellular immunity and
support the definitive rationale of the clinical development of
this strategy against a broad range of cancers.
[0031] Regarding HLA antigens, the data presented here show that
the uses of A-24 type or A-02 type (which are said to be highly
expressed among the Japanese) are favorable for obtaining effective
results. The uses of subtypes such as A-2402 and A-0201 are even
more preferable. However, in the clinic, the type of HLA antigen of
the patient requiring treatment is investigated in advance, which
enables appropriate selection of peptides having high levels of
binding affinity to this antigen, or having cytotoxic T cell (CTL)
inducibility by antigen presentation. Furthermore, in order to
obtain peptides showing high binding affinity and CTL inducibility,
substitution or addition of 1, 2, or several amino acids may be
performed based on the amino acid sequence of the naturally
occurring VEGFR1 partial peptide. Herein, the term "several" means
5 or less, or preferably 3 or less. Furthermore, in addition to
peptides that are naturally displayed, since the regularity of the
sequences of peptides displayed by binding to HLA antigens is
already known (Kubo R T, et al., (1994) J. Immunol., 152, 3913-24.;
Rammensee H G, et al., (1995) Immunogenetics. 41:178-228; Kondo A,
et al., (1994) J. Immunol. 155:4307-12.), modifications based on
such regularity can be performed on the obtained peptides. For
example, peptides showing high HLA-24 binding affinity have their
second amino acid from the N terminus substituted with
phenylalanine, tyrosine, methionine, or tryptophan, and peptides
whose amino acid at the C terminus is substituted with
phenylalanine, leucine, isoleucine, tryptophan, or methionine may
also be used favorably. On the other hand, peptides showing high
HLA-0201 binding affinity have their second amino acid from the N
terminus substituted with leucine or methionine, and peptides whose
C-terminal amino acid is substituted with valine or leucine may be
used favorably. Furthermore, 1 to 2 amino acids may be added to the
N terminus and/or C terminus of the peptide.
[0032] However, when the peptide sequence is identical to a portion
of the amino acid sequence of an endogenous or exogenous protein
having a different function, side effects such as autoimmune
disorders or allergic symptoms against specific substances may be
induced, therefore, preferably, situations in which the sequence
matches the amino acid sequence of another protein is avoided by
performing a homology search using available databases.
Furthermore, if it is clear from homology searches that not even
peptides in which 1 or 2 amino acids are different exist, there is
no danger that modifications of the above-mentioned amino acid
sequence in order to increase the binding affinity with HLA
antigens, and/or increase the CTL inducibility will cause such
problems.
[0033] Although peptides having high binding affinity to the HLA
antigens as described above are expected to be highly effective as
cancer vaccines, the candidate peptides, which are selected
according to the presence of high binding affinity as an indicator,
must be examined for the actual presence of CTL inducibility.
Confirmation of CTL inducibility is accomplished by inducing
antigen-presenting cells carrying human MHC antigens (for example,
B-lymphocytes, macrophages, and dendritic cells), or more
specifically dendritic cells derived from human peripheral blood
mononuclear leukocytes, and after stimulation with the peptides,
mixing with CD8-positive cells, and then measuring the cytotoxic
activity against the target cells. As the reaction system,
transgenic animals that have been produced to express a human HLA
antigen (for example, those described in BenMohamed et al., (2000)
Hum. Immunol.; 61(8):764-79 Related Articles, Books, Linkout.) may
be used. For example, the target cells can be radiolabeled with
.sup.51Cr and such, and cytotoxic activity can be calculated from
radioactivity released from the target cells. Alternatively, it can
be examined by measuring IFN-.gamma. produced and released by CTL
in the presence of antigen-presenting cells that carry immobilized
peptides, and visualizing the inhibition zone on the media using
anti-IFN-.gamma. monoclonal antibodies.
[0034] As a result of examining the CTL inducibility of peptides as
described above, those having high binding affinity to an HLA
antigen did not necessarily have high inducibility. Furthermore,
nonapeptides or decapeptides selected from peptides comprising the
amino acid sequences indicated by VLLWEIFSL (SEQ ID NO: 1),
TLFWLLLTL (SEQ ID NO: 2), NLTATLIVNV (SEQ ID NO: 13), SYGVLLWEIF
(SEQ ID NO: 32) showed particularly high CTL inducibility.
[0035] Furthermore, the present invention provides immunogenic
peptides of less than about 40 amino acids, often less than about
20 amino acids, usually less than about 15 amino acids having
cytotoxic T cell inducibility, and comprising the amino acid
sequence of SEQ ID NO: 32 in which 1, 2, or several amino acids are
substituted or added. In some preferred embodiments, the
immunogenic peptide has an amino acid sequence comprising 10 amino
acids indicated in SEQ ID NO: 32 in which 1, 2, or several amino
acids are substituted or added may have CTL inducibility as long as
it does not match the amino acid sequence of other proteins. In
particular, amino acid substitution to phenylalanine, tyrosine,
methionine, or tryptophan at the second amino acid from the N
terminus, and to phenylalanine, leucine, isoleucine, tryptophan, or
methionine at the C-terminal amino acid, and amino acid addition of
1 to 2 amino acids at the N terminus and/or C terminus are
favorable examples. One of skill will recognize that in addition to
amino acid substitutions and additions, immunologically active
fragments of the peptides may also be used in the methods of the
invention. Methods for determining active fragments are well known
in the art.
[0036] The present invention also provides peptides having
cytotoxic T cell inducibility, and comprising the amino acid
sequence of SEQ ID NOS: 1, 2, or 13, in which 1, 2, or several
amino acids are substituted or added. The amino acid sequence
comprising 9 or 10 amino acids indicated by SEQ ID NOS: 1, 2, or 13
in which 1, 2, or several amino acids are substituted or added may
have CTL inducibility as long as it does not match the amino acid
sequence of other proteins. In particular, amino acid substitution
to leucine, or methionine at the second amino acid from the N
terminus, and to valine, or leucine at the C-terminal amino acid,
and amino acid addition of 1 to 2 amino acids at the N terminus
and/or C terminus are favorable examples. One of skill will
recognize that in addition to amino acid substitutions and
additions, immunologically active fragments of the peptides may
also be used in the methods of the invention. Methods for
determining active fragments are well known in the art. CTL clones
obtained by stimulation by these modified peptides can recognize
the original peptides and cause damage.
[0037] Peptides of the invention can be prepared using well known
techniques. For example, the peptides can be prepared
synthetically, by recombinant DNA technology or chemical synthesis.
Peptide of the invention may be synthesized individually or as
longer polypeptides comprising two or more peptides. The peptide
are preferably isolated i.e., substantially free of other naturally
occurring host cell proteins and fragments thereof.
[0038] The peptides may contain modifications such as
glycosylation, side chain oxidation, or phosphorylation; so long as
the modifications do not destroy the biological activity of the
peptides as described herein. Other modifications include
incorporation of D-amino acids or other amino acid mimetics that
can be used, for example, to increase serum half life of the
peptides.
[0039] The peptides of this invention can be prepared into a
combination, which comprises 1 or more peptides of the invention,
for use as a cancer vaccine that may induce CTL in vivo or ex vivo.
The peptides may be in a cocktail or may be conjugated to each
other using standard techniques. For example, the peptides can be
expressed as a single polypeptide sequence. The peptides in the
combination may be the same or different. By administering the
peptides of this invention, the peptides are presented at a high
density on the HLA antigens of antigen-presenting cells, then CTL
that specifically react toward the complex formed between the
displayed peptide and the HLA antigen are induced, and strong
immune response against vascular endothelial cells in the tumor
cells is induced. Alternatively, antigen presenting cells that have
immobilized the peptides of this invention on their cell surface
are obtained by removing dendritic cells from the subjects, these
are stimulated ex vivo by the peptides of this invention, CTL are
induced in the subjects by readministering these cells to the
subjects, and as a result, aggressiveness towards the target cells
can be increased.
[0040] More specifically, the present invention provides
immunogenic compositions for treating tumors or preventing
proliferation, metastasis, and the like of tumors. The compositions
comprise 1 or more peptides of this invention. The peptides may be
the same or different in the compositions. Furthermore,
angiogenesis at the pathologic site is closely linked to tumors, as
well as diseases such as diabetic retinopathy, chronic rheumatoid
arthritis, psoriasis, and atherosclerosis, and also to metastasis
of solid tumors (Folkman, J., (1995) Nature Med. 1:27-31.; Bicknell
et al., (1996) Curr. Opin. Oncol. 8:60-5.). Therefore, the peptides
of this invention can be used for treating tumors,
angiogenesis-mediated disease such as diabetic retinopathy, chronic
rheumatoid arthritis, psoriasis, and atherosclerosis, as well as
metastasis of solid tumors.
[0041] The peptides of this invention were found to inhibit the
formation of tortuous blood vessels, which are morphologically
different from normal blood vessels and are formed in malignant
tumor tissues, and results of analyzing wound healing and fertility
in vaccinated mice confirmed that there are no adverse effects on
normal physiological angiogenesis. Furthermore, when cytotoxicity
against non-proliferative or proliferative endothelial cells was
tested in vitro using CTL clones that recognize the peptides of
this invention, these clones were found to show stronger activity
towards proliferative endothelial cells than towards
non-proliferative endothelial cells. More specifically, they
function very specifically to disorders in which proliferative
endothelial cells are observed, and particularly to cancer.
[0042] In vivo and in vitro stimulation of dendritic cells by the
peptides of this invention can be performed easily by exposing the
cells to a high concentration of the peptides so that these
peptides exchange with peptides that were originally immobilized on
the cells. Therefore, the peptides used in this invention must have
at least a certain level of binding affinity to HLA antigens.
[0043] The peptides of this invention can be administered directly
or as a pharmaceutical composition that has been formulated by
conventional formulation methods. In such cases, in addition to the
peptides of this invention, carriers, excipients, and such that are
ordinarily used for drugs can be included as appropriate without
particular limitations. The immunogenic compositions of this
invention may be used for treatment and prevention of various
tumors such as gastric cancer, duodenal cancer, colon cancer, lung
cancer, breast cancer, prostate cancer, and brain tumor. The
peptides of this invention targets the endothelial cells of blood
vessels that are newly formed in tumor tissues, and do not target
the tumor cells themselves, therefore, a wide variety of tumors
become targets of treatment, and there are no particular
limitations to their use.
[0044] Immunogenic compositions for treatment and/or prevention of
tumors, which comprise the peptides of this invention as the active
ingredients, can be administered with an adjuvant so that cellular
immunity will be established effectively, or they may be
administered with other active ingredients such as antitumor
agents, and they may be administered by formulation into granules.
An adjuvant that may be applied includes those described in the
literature (Johnson A G. (1994) Clin. Microbiol. Rev., 7:277-89.).
Exemplary adjuvants include, aluminum phosphate, aluminum
hydroxide, or alum. Furthermore, liposome formulations, granular
formulations in which the drug is bound to few .mu.m diameter
beads, and formulations in which a lipid is bound to the drug may
be conveniently used. The method of administration may be oral,
intradermal, subcutaneous, intravenous injection, or such, and
systemic administration or local administration to the vicinity of
the targeted tumor is possible. The dose of the peptides of this
invention can be adjusted appropriately according to the disease to
be treated, age of the patient, weight, method of administration,
and such, and is ordinarily 0.001 mg to 1000 mg, preferably 0.01 mg
to 100 mg, more preferably 0.1 mg to 10 mg, and is preferably
administered once in a few days to few months. One skilled in the
art can appropriately select the suitable dose.
[0045] Alternatively, the present invention provides intracellular
vesicles called exosomes, which present complexes formed between
the peptides of this invention and HLA antigens on their surface.
Exosomes can be prepared, for example by using the methods
described in detail in Published Japanese Translation of
International Publication Nos. Hei 11-510507 and 2000-512161, and
is preferably prepared using antigen presenting cells obtained from
subjects who are targets of treatment and/or prevention. The
exosomes of this invention can be inoculated as cancer vaccines,
similarly to the peptides of this invention.
[0046] The type of HLA antigens used must match that of the subject
requiring treatment and/or prevention. For example, for a Japanese,
HLA-A24 or HLA-A02, particularly HLA-A2402 or HLA-0201 is often
appropriate.
[0047] In some embodiments the vaccine compositions of the
invention comprise a component which primes cytotoxic T
lymphocytes. Lipids have been identified as agents capable of
priming CTL in vivo against viral antigens. For example, palmitic
acid residues can be attached to the .epsilon.- and .alpha.-amino
groups of a lysine residue and then linked to an immunogenic
peptide of the invention. The lipidated peptide can then be
administered either directly in a micelle or particle, incorporated
into a liposome, or emulsified in an adjuvant. As another example
of lipid priming of CTL responses, E. coli lipoproteins, such as
tripalmitoyl-S-glycerylcysteinlyseryl-serine (P3CSS) can be used to
prime CTL when covalently attached to an appropriate peptide (see,
e.g., Deres, et al., (1989) Nature 342:561-4.).
[0048] The immunogenic compositions of the invention may also
comprise nucleic acids encoding the immunogenic peptides disclosed
here. See, e.g., Wolff et al., (1990) Science 247:1465-8; U.S. Pat.
Nos. 5,580,859; 5,589,466; 5,804,566; 5,739,118; 5,736,524;
5,679,647; and WO 98/04720. Examples of DNA-based delivery
technologies include "naked DNA", facilitated (bupivicaine,
polymers, peptide-mediated) delivery, cationic lipid complexes, and
particle-mediated ("gene gun") or pressure-mediated delivery (see,
e.g., U.S. Pat. No. 5,922,687).
[0049] The immunogenic peptides of the invention can also be
expressed by viral or bacterial vectors. Examples of expression
vectors include attenuated viral hosts, such as vaccinia or
fowlpox. This approach involves the use of vaccinia virus, e.g., as
a vector to express nucleotide sequences that encode the peptide.
Upon introduction into a host, the recombinant vaccinia virus
expresses the immunogenic peptide, and thereby elicits an immune
response. Vaccinia vectors and methods useful in immunization
protocols are described in, e.g., U.S. Pat. No. 4,722,848. Another
vector is BCG (Bacille Calmette Guerin). BCG vectors are described
in Stover, et al., (1991) Nature 351:456-60. A wide variety of
other vectors useful for therapeutic administration or immunization
e.g., adeno and adeno-associated virus vectors, retroviral vectors,
Salmonella typhi vectors, detoxified anthrax toxin vectors, and the
like, will be apparent. See, e.g., Shata, et al., (2000) Mol. Med.
Today 6:66-71; Shedlock, et al., (2000) J. Leukoc. Biol.
68:793-806; and Hipp, et al., (2000) In vivo 14:571-85.
[0050] The present invention also provides methods of inducing
antigen-presenting cells using the peptides of this invention. The
antigen-presenting cells can be induced by inducing dendritic cells
from the peripheral blood monocytes and then contacting
(stimulating) them with the peptides of this invention in vitro or
in vivo. When the peptides of this invention are administered to
the subjects, antigen-presenting cells that have the peptides of
this invention immobilized to them are induced in the body of the
subject. Alternatively, after immobilizing the peptides of this
invention to the antigen-presenting cells, the cells can be
administered to the subject as a vaccine.
[0051] This invention also provides a method for inducing
antigen-presenting cells having a high level of cytotoxic T cell
inducibility, in which the method comprises the step of
transferring genes comprising polynucleotides that encode the
peptides of this invention to antigen-presenting cells in vitro.
The introduced genes may be in the form of DNAs or RNAs. For the
method of introduction, without particular limitations, various
methods conventionally performed in this field, such as
lipofection, electroporation, and calcium phosphate method may be
used. More specifically, it may be performed as described in Reeves
M E, et al., (1996) Cancer Res., 56:5672-7.; Butterfield L H, et
al., (1998) J. Immunol., 161:5607-13.; Boczkowski D, et al., (1996)
J. Exp. Med., 184:465-72.; Published Japanese Translation of
International Publication No. 2000-509281. By transferring the gene
into antigen-presenting cells, the gene undergoes transcription,
translation, and such in the cell, and then the obtained protein is
processed and binded to MHC Class I or Class II, and proceeds
through a presentation pathway to present partial peptides.
[0052] Furthermore, the present invention provides methods for
inducing CTL using the peptides of this invention. When the
peptides of this invention are administered to a subject, CTL is
induced in the body of the subject, and the strength of the immune
system targeting the angiogenic endothelial cells in the tumor
tissues is enhanced. Alternatively, they may be used for an ex vivo
therapeutic method, in which subject-derived antigen-presenting
cells, and CD8-positive cells, or peripheral blood mononuclear
leukocytes are contacted (stimulated) with the peptides of this
invention in vitro, and after inducing CTL, the cells are returned
to the subject.
[0053] Furthermore, the present invention provides isolated
cytotoxic T cells that are induced using the peptides of this
invention. The cytotoxic T cells, which have been induced by
stimulation from antigen-presenting cells that present the peptides
of this invention, are preferably derived from subjects who are
targets of treatment and/or prevention, and can be administered by
themselves or in combination with other drugs including the
peptides of this invention or exosomes for the purpose of antitumor
effects. The obtained cytotoxic T cells act specifically against
target cells presenting the peptides of this invention, or
preferably the same peptides used for induction. The target cells
may be cells that express VEGFR1 endogenously, or cells that are
transfected with a gene that encodes VEGFR1, and cells that present
the peptides of this invention on the cell surface due to
stimulation by these peptides can also become targets of
attack.
[0054] The present invention also provides antigen-presenting cells
that comprise presentation of complexes formed between HLA antigens
and the peptides of this invention. The antigen-presenting cells
that are obtained by contacting the peptides of this invention, or
the nucleotides encoding the peptides of this invention are
preferably derived from subjects who are the targets of treatment
and/or prevention, and can be administered as vaccines by
themselves or in combination with other drugs including the
peptides of this invention, exosomes, or cytotoxic T cells.
[0055] In the present invention, the phrase "vaccine" (also
referred to as an immunogenic composition) refers to a substance
that has the function to induce immunity against tumor endothelial
cells to suppress tumors upon inoculation into animals. According
to the present invention, polypeptides comprising the amino acid
sequence of SEQ ID NO: 1, 2, 13 were suggested to be HLA-A02
restricted epitope peptides and SEQ ID NO: 32 was suggested to be
HLA-A24 restricted epitope peptides that may induce potent and
specific immune response against tumor endothelial cells expressing
VEGFR1. Thus, the present invention also encompasses method of
inducing anti-tumor immunity using polypeptides comprising the
amino acid sequence of SEQ ID NO: 1, 2, 13, 32. In general,
anti-tumor immunity includes immune responses such as follows:
[0056] induction of cytotoxic lymphocytes against endothelial cells
in tumors, [0057] induction of antibodies that recognize
endothelial cells in tumors, and [0058] induction of anti-tumor
cytokine production.
[0059] Therefore, when a certain protein induces any one of these
immune responses upon inoculation into an animal, the protein is
decided to have anti-tumor immunity inducing effect. The induction
of the anti-tumor immunity by a protein can be detected by
observing in vivo or in vitro the response of the immune system in
the host against the protein.
[0060] For example, a method for detecting the induction of
cytotoxic T lymphocytes is well known. A foreign substance that
enters the living body is presented to T cells and B cells by the
action of antigen presenting cells (APCs). T cells that respond to
the antigen presented by APC in antigen specific manner
differentiate into cytotoxic T cells (or cytotoxic T lymphocytes;
CTLs) due to stimulation by the antigen, and then proliferate (this
is referred to as activation of T cells). Therefore, CTL induction
by a certain peptide can be evaluated by presenting the peptide to
a T cell by APC, and detecting the induction of CTL. Furthermore,
APCs have the effect of activating CD4+ T cells, CD8+ T cells,
macrophages, eosinophils and NK cells. Since CD4+ T cells are also
important in anti-tumor immunity, the anti-tumor immunity inducing
action of the peptide can be evaluated using the activation effect
of these cells as indicators.
[0061] A method for evaluating the inducing action of CTL using
dendritic cells (DCs) as APC is well known in the art. DC is a
representative APC having the strongest CTL inducing action among
APCs. In this method, the test polypeptide is initially contacted
with DC and then this DC is contacted with T cells. Detection of T
cells having cytotoxic effects against the cells of interest after
the contact with DC shows that the test polypeptide has an activity
of inducing the cytotoxic T cells. Activity of CTL against tumors
can be detected, for example, using the lysis of .sup.51Cr-labeled
tumor cells as the indicator. Alternatively, the method of
evaluating the degree of tumor cell damage using .sup.3H-thymidine
uptake activity or LDH (lactose dehydrogenase)-release as the
indicator is also well known.
[0062] Apart from DC, peripheral blood mononuclear cells (PBMCs)
may also be used as the APC. The induction of CTL is reported to be
enhanced by culturing PBMC in the presence of GM-CSF and IL-4.
Similarly, CTL has been shown to be induced by culturing PBMC in
the presence of keyhole limpet hemocyanin (KLH) and IL-7.
[0063] The test polypeptides confirmed to possess CTL inducing
activity by these methods are polypeptides having DC activation
effect and subsequent CTL inducing activity. Therefore,
polypeptides that induce CTL against tumor endothelial cells are
useful as vaccines against tumors. Furthermore, APC that acquired
the ability to induce CTL against tumor endothelial cells by
contacting with the polypeptides are useful as vaccines against
tumors. Furthermore, CTL that acquired cytotoxicity due to
presentation of the polypeptide antigens by APC can be also used as
vaccines against tumors. Such therapeutic methods for tumors using
anti-tumor immunity due to APC and CTL are referred to as cellular
immunotherapy.
[0064] Generally, when using a polypeptide for cellular
immunotherapy, efficiency of the CTL-induction is known to increase
by combining a plurality of polypeptides having different
structures and contacting them with DC. Therefore, when stimulating
DC with protein fragments, it is advantageous to use a mixture of
multiple types of fragments.
[0065] Alternatively, the induction of anti-tumor immunity by a
polypeptide can be confirmed by observing the induction of antibody
production against tumors. For example, when antibodies against a
polypeptide are induced in a laboratory animal immunized with the
polypeptide, and when growth, proliferation or metastasis of tumor
cells is suppressed by those antibodies, the polypeptide can be
determined to have an ability to induce anti-tumor immunity.
[0066] The present invention also relates to a method of treating
or preventing tumors in a subject comprising administering to said
subject a vaccine comprising a polypeptide encoded by a nucleic
acid selected from the group consisting of VEGFR1 or an
immunologically active fragment of said polypeptide, or a
polynucleotide encoding the polypeptide or the fragment thereof.
Administration of the polypeptide induces an anti-tumor immunity in
a subject. Thus, the present invention further provides a method
for inducing anti tumor immunity. The polypeptide or the
immunologically active fragments thereof are useful as vaccines
against tumors. In some cases the proteins or fragments thereof may
be administered in a form bound to the T cell receptor (TCR) or
presented on an antigen presenting cell (APC), such as macrophage,
dendritic cell (DC) or B-cells. Due to the strong antigen
presenting ability of DC, the use of DC is most preferable among
the APCs.
[0067] Anti-tumor immunity is induced by administering the vaccine
of this invention, and the induction of anti-tumor immunity enables
treatment and prevention of tumors. Therapy against or prevention
of the onset of tumors includes any of the steps, such as
inhibition of the growth of tumors cells, involution of tumors
cells and suppression of occurrence of tumors cells. Decrease in
mortality of individuals having tumors, decrease of tumors markers
in the blood, alleviation of detectable symptoms accompanying
tumors and such are also included in the therapy or prevention of
tumors. Such therapeutic and preventive effects are preferably
statistically significant. For example, in observation, at a
significance level of 5% or less, wherein the therapeutic or
preventive effect of a vaccine against tumors is compared to a
control without vaccine administration. For example, Student's
t-test, the Mann-Whitney U-test or ANOVA may be used for
statistical analyses.
[0068] The above-mentioned protein having immunological activity,
or a polynucleotide or vector encoding the protein may be combined
with an adjuvant. An adjuvant refers to a compound that enhances
the immune response against the protein when administered together
(or successively) with the protein having immunological activity.
Examples of adjuvants include cholera toxin, salmonella toxin, alum
and such, but are not limited thereto. Furthermore, the vaccine of
this invention may be combined appropriately with a
pharmaceutically acceptable carrier. Examples of such carriers are
sterilized water, physiological saline, phosphate buffer, culture
fluid and such. Furthermore, the vaccine may contain as necessary,
stabilizers, suspensions, preservatives, surfactants and such. The
vaccine is administered systemically or locally. Vaccine
administration may be performed by single administration or boosted
by multiple administrations.
[0069] When using APC or CTL as the vaccine of this invention,
tumors can be treated or prevented, for example, by the ex vivo
method. More specifically, PBMCs of the subject receiving treatment
or prevention are collected, the cells are contacted with the
polypeptide ex vivo, and following the induction of APC or CTL, the
cells may be administered to the subject. APC can be also induced
by introducing a vector encoding the polypeptide into PBMCs ex
vivo. APC or CTL induced in vitro can be cloned prior to
administration. By cloning and growing cells having high activity
of damaging target cells, cellular immunotherapy can be performed
more effectively. Furthermore, APC and CTL isolated in this manner
may be used for cellular immunotherapy not only against individuals
from whom the cells are derived, but also against similar types of
diseases in other individuals.
[0070] The following examples are presented to illustrate the
present invention and to assist one of ordinary skill in making and
using the same. The examples are not intended in any way to
otherwise limit the scope of the invention.
[0071] Unless otherwise defined, all technical and scientific terms
used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which this invention belongs. Although
methods and materials similar or equivalent to those described
herein can be used in the practice or testing of the present
invention, suitable methods and materials are described below. Any
patents, patent applications, and publications cited herein are
incorporated by reference.
EXAMPLES
[0072] The present invention is illustrated in details by following
Examples, but is not restricted to these Examples.
Materials and Methods
Cell Lines
[0073] The T2 cell line was generously provided by Dr. H. Shiku
(Mie University School of Medicine). The AG1-G1-Flt-1 and
AG1-G1-Neo cell lines were kindly provided by Dr. M. Shibuya
(Institute of Medical Science, The University of Tokyo). The AG1-G1
cell line was established from human benign hemangioma, and
AG1-G1-Flt-1 was generated infecting the AG1-G1 cell lines with the
BCMGS plasmid vector carrying VEGFR1 cDNA. MCA205, a
methylcholanthrene-induced murine fibrosarcoma cell line, was
generous gifts from Dr. S. A. Rosenberg (National Cancer Institute,
Bethesda, Md.). B16, a murine melanoma, and MC38, a murine colon
adenocarcinoma were purchased from ATCC.
Synthetic Peptides
[0074] The candidates of VEGFR1 derived epitope peptides restricted
to HLA-A*0201 (A2) and -A*2402 (A24) were selected based on the
binding affinities to the corresponding HLAs. The binding
affinities were predicted with the website of BioInformatics &
Molecular Analysis Section (BIMAS) (Kuzushima et al., (2003) Blood.
101: 1460-8., Parker et al., (1994) J. Immunol. 152: 163-75.).
These candidate peptides were synthesized by Sawady Technology,
Japan according to the standard solid phase synthesis method and
purified by reversed phase HPLC. The purity (>95%) and the
identity of the peptides were determined by analytical HPLC and
mass spectrometry analysis, respectively. The peptides used in the
present invention are listed in Table 1 and 2.
[0075] CEA peptide (DVLYGPDTPI (SEQ ID NO. 41)) was used as a
positive control for in vivo mouse model. CMV peptides
(A02;NLVPMVATV (SEQ ID NO. 42), A24;QYDPVAALF (SEQ ID NO. 43)) were
used as positive controls for human CTL induction in vitro (Solache
et al., (1999) J. Immunol. 163: 5512-8., Kuzushima et al., (2001)
Blood. 98: 1872-81.).
Animals
[0076] The A2/Kb TGM, of which MHC class I consists of .alpha.1 and
.alpha.2 domain of HLA-A*0201 and .alpha.3 domain of mouse H-2 Kb,
were prepared as described elsewhere (Wentworth et al., (1996) Eur.
J. Immunol. 26: 97-101.). The animals were maintained in the
specific-pathogen-free Animal Facility of the Institute of Medical
Science, The University of Tokyo, and all the protocols for animal
experiments were approved by the ethical committee of our
institute.
Generation of CTL Lines and Clones
[0077] Monocyte-derived dendritic cells (DCs) were used to induce
CTL responses against peptides presented on HLA as previously
described (Nukaya et al., (1999) Int. J. Cancer. 80: 92-7., Tsai et
al., (1997) J. Immunol. 158: 1796-802., Nakahara et al., (2003)
Cancer Res. 63: 4112-8.). In brief, the PBMCs were obtained from
the healthy volunteers with corresponding HLAs and cultured in the
presence of GM-CSF (provided by Kirin Brewery Company, Japan) and
IL-4 (Genzyme/Techne, Minneapolis). After culture for 5 days,
OK-432 (Chugai Pharmaceutical Corporation, Japan) was added to the
culture to obtain mature DCs (Nakahara et al., (2003) Cancer Res.
63: 4112-8.). On day 7, generated mature DCs were pulsed with each
peptide for T cell stimulation. Using these peptide-pulsed DCs each
time, the autologous CD8+ T cells were stimulated for three times
on day 0, 7 and 14, and then the resultant lymphoid cells were
tested for their cytotoxic activities on day 21.
[0078] To generate CTL clones, established CTL lines were plated in
96-well plates at 0.3, 1, and 3 cells per well with allogenic PBMCs
and A3-LCL as stimulator cells. Cytotoxic activities of resulting
CTL clones were tested on the 14th day.
Cytotoxicity Assay
[0079] Cytotoxic activities were measured using a standard 4-h
.sup.51Cr-release assay. The T2 cells and A24-LCL were used as
target cells pulsed with candidate peptides. Percent specific lysis
was calculated as follows:
% Specific lysis=[(experimental release-spontaneous
release)/(maximum release-spontaneous release)].times.100.
Immunogenicity of Epitope Peptides in A2/Kb TGM
[0080] For priming the peptide-specific CTLs, immunization was
given using 200 .mu.l of vaccine mixture, which contains 100 .mu.g
of an HLA-A2 restricted peptide and 100 .mu.l of IFA per mouse. The
vaccine was injected intradermally in the right flank for the first
immunization on day 0 and in the other flank for the second on day
11. On day 21, splenocytes of the vaccinated mice were used as the
responder cells, and T2 cells pulsed with or without peptides were
used as the stimulator cells for ELISPOT assay.
In Vivo Angiogenesis Assay
[0081] We examined the effects of peptide vaccination using dorsal
air sac (DAS) assay which was designed to measure in vivo
angiogenesis induced by tumor cells as previously described (Oikawa
et al., (1997) Anticancer Res. 17: 1881-6.). In brief, the A2/Kb
TGM were vaccinated twice with 1-week interval in the left flank
using IFA conjugated corresponding peptides as previously described
with some modification (Schuler et al., (1997) J. Exp. Med. 186:
1183-7., Song et al., (1997) J. Exp. Med. 186: 1247-56., Specht et
al., (1997) J. Exp. Med. 186: 1213-21.). Millipore chamber
(Millipore Corporation, Bedford, Mass.) was filled with PBS
containing MC38 cells (1.times.10.sup.6 cells) and implanted in the
dorsum of anesthetized mice on day 0. The implanted chambers were
removed from s.c. fascia on day 6 and then black rings were placed
at the sites exposed to a direct contact with the chamber. The
angiogenic response was assessed with photographs taken using a
dissecting microscope. The extent of angiogenesis was determined
with the number of newly formed blood vessels of >3 mm in length
and scored semi quantitatively using an index ranging from 0 (none)
to 5 (many).
In Vivo Anti-Tumor Effects
[0082] We examined the anti-tumor effects of this vaccination with
a therapeutic model. The 1.times.10.sup.5 MCA205 cells or the
5.times.10.sup.5 B16 cells were injected i.d. in the right flank on
day 0, and vaccination was performed on day 4 and day 14 using IFA
conjugated corresponding peptides.
Statistical Analysis
[0083] Each experiment was performed in triplicate to confirm
reproducibility of the results, and representative results are
shown. Student's t test was used to examine the significance of the
data, when applicable. The difference was considered to be
statistically significant when P value was less than 0.05.
Results
[0084] HLA Class I Binding Predicted Peptides from VEGFR1
Protein
[0085] The candidates of VEGFR1 derived epitope peptides restricted
to HLA-A*0201 (A2) and -A*2402 (A24) were selected based on the
binding affinities to the corresponding HLAs. The binding
affinities were predicted with the website of BioInformatics &
Molecular Analysis Section (BIMAS).
[0086] HLA Peptide Binding Prediction software:
[0087] (//bimas.dcrt.nih.gov/cgi-bin/molbio/ken parker
comboform)
[0088] Kuzushima, K., et al., (2003) Blood. 101: 1460-8.
[0089] Parker, K. C., et al., (1994) J. Immunol. 152: 163-75.
Establishment of CTL Clones Using Epitope Candidates Derived from
VEGFR1
[0090] We first tested the immunogenicity of VEGFR1 to determine
the epitope peptides. Epitope-candidate peptides were selected in
the order of the binding scores reflecting binding affinity of the
peptide to the HLA class I molecules (Table 1, Table 2).
TABLE-US-00001 TABLE 1 HLA-A*0201 binding predicted peptides from
VEGFR1 protein Start Sequence SEQ ID Binding Start Sequence SEQ ID
Binding Position (9 mer) No. affinity position (10 mer) No.
affinity 1087 VLLWEIFSL 1 1793 1153 KLGDLLQANV 11 998 770 TLFWLLLTL
2 182 1029 LLSENNVVKI 12 167 1028 ILLSENNVV 3 179 417 NLTATLIVNV 13
160 766 CVAATLFWL 4 137 1094 SLGGSPYPGV 14 104 874 ALMTELKIL 5 75
1104 QMDEDFCSRL 15 96 861 KMLKEGATA 6 47 1086 GVLLWEIFSL 16 92 875
LMTELKILT 7 38 797 IIMDPDEVPL 17 76 881 ILTHIGHHL 8 36 1004
FQVARGMEFL 18 62 1027 NILLSENNV 9 35 220 YLTHRQTNTI 19 48 220
YLTHRQTNT 10 34 590 ILLRTVNNRT 20 47
TABLE-US-00002 TABLE 2 HLA-A*2402 binding predicted peptides from
VEGFR1 protein Start Sequence SEQ ID Binding Start Sequence SEQ ID
Binding position (9 mer) No. affinity position (10 mer) No.
affinity 913 KYGNLSNYL 21 576 919 NYLKSKRDLF 31 150 919 NYLKSKRDL
22 300 1084 SYGVLLWEIF 32 120 871 EYKALMTEL 23 264 1001 SYSFQVARGM
33 35 1212 RYVNAFKFM 24 90 880 KILTHIGHHL 34 17 1084 SYGVLLWEI 25
66 1003 SFQVARGMEF 35 17 1146 RFAELVEKL 26 64 1212 RYVNAFKFMS 36 15
821 EFARERLKL 27 22 700 KIQQEPGIIL 37 12 754 KSNLELITL 28 12 873
KALMTELKIL 38 12 819 KWEFARERL 29 12 1149 ELVEKLGDLL 39 9 814
PYDASKWEF 30 11 1079 KSDVWSYGVL 40 8
[0091] We generated CTLs using these peptides and PBMCs given from
healthy volunteers with HLA-A*0201 and HLA-A*2402 as described in
"Materials and Methods", and CTL clones were successfully
established.
[0092] These CTL clones showed specific cytotoxicity against the
target cells pulsed with corresponding peptides (FIG. 1, FIG.
2).
[0093] We also examined the ability of established CTL clones
induced with these peptides to lyse the target cells endogenously
expressing VEGFR1 as well.
[0094] HLA-A*2402 CTL clone was examined for the cytotoxicity
against VEGFR1 expressing cells (AG1-G1-Flt-1) and control (AG1-G1)
with a 4-hr .sup.51Cr-release assay. These CTL clones showed the
cytotoxicities against AG1-G1-Flt-1, but not against AG1-G1 (FIG.
3). The cytotoxicity was significantly blocked with mAbs against
CD8 and HLA-class I, but was not blocked using mAbs against CD4 nor
HLA-class II (data not shown).
In Vivo Anti-Angiogenesis and Anti-Tumor Effects Associated with
the Vaccination Using VEGFR1-Epitope Peptides.
[0095] We tested in vivo anti-angiogenesis effects and anti-tumor
effects of vaccination with VEGFR1-epitope peptides using A2/Kb
TGM.
[0096] At first, we evaluated the immunogenicity of the epitope
peptides for A2/Kb TGM to examine the specific production of
IFN-.gamma. of the CTLs induced with these peptides by ELISPOT
assay (FIG. 4). IFA-conjugated peptide was injected s.c. into A2/Kb
TGM on day 0 and day 11. On day 21, splenocytes of the vaccinated
mice were harvested and used as the responder cells, and T2 cells
pulsed with or without peptides were used as the stimulator cells
for ELISPOT assay. Specific production of IFN-.gamma. for the
corresponding peptide was observed in the mice vaccinated with
VEGFR1-1087, -770, -417 peptides. In this ELISPOT assay using A2/Kb
TGM system, positive results were shown for the epitope peptides
identified using human PBMCs.
[0097] We examined whether the vaccination using peptide derived
from VEGFR1 suppress the tumor-induced angiogenesis. To confirm the
effects of the peptide vaccination on angiogenesis induced by tumor
cells, we employed dorsal air sac assay (DAS assay) which
visualizes the extent of neo-vascularization in vivo. In this
semiquantitative assay, significant inhibition on angiogenesis was
observed in the mice vaccinated with VEGFR1-1087, -770, -417
peptides (FIG. 5).
[0098] The vaccination using the epitope peptide showed strong
antitumor effect in therapeutic model. The MCA205, a
methylcholanthrene-induced murine fibrosarcoma cell line were
injected i.d. into A2/Kb TGM on day 0, and vaccination was
performed on these mice on 4 and 14 days after the tumor challenge
using VEGFR1-1087, -770, -417 peptides conjugated with IFA (FIG.
6). Significant suppression of tumor growth was observed with the
vaccination using VEGFR1-1087, -770 peptides conjugated with IFA.
Furthermore, significant inhibitions of tumor growth were observed
in various tumor cells (data not shown).
[0099] These results strongly suggest that the anti tumor effects
induced with the vaccination using the peptides derived from VEGFR1
might be mediated by the inhibition of tumor-angiogenesis. Thus,
vaccination with epitope peptides derived from VEGFR1 could affect
the growth of the tumor cells through the effects on the
VEGFR1-expressing endothelial cells of the vessels which support
the tumor growth in vivo in this A2/Kb TGM-tumor system.
Discussion
[0100] Identification of the tumor associate antigens (TAAs) has
enabled the clinical development of peptide-based cancer vaccine,
which could induce CTLs and lyse tumor cells in HLA class I
restricted fashion (Bruggen et al., (1991) Science. 254: 1643-7.,
Boon et al., (1996) J. Exp. Med. 183: 725-9., Rosenberg et al.,
(1998) Nat. Med. 4: 321-7., Butterfield et al., (1999) Cancer Res.
59: 3134-42.). Until now, multiple clinical trials using TAA
peptides have reported that tumor regressions were observed in
approximately 20% rate of the melanoma patients. However, complete
response has rarely been reported (Rosenberg et al., (1998) Nat.
Med. 4: 321-7. Nestle et al., (1998) Nat. Med. 4: 328-32., Thurner
et al., (1999) J. Exp. Med. 190: 1669-78., Belli et al., (2002)
Parmiani. J. Clin. Oncol. 20: 4169-80., Coulie et al., (2002)
Immunol. Rev. 188: 33-42.). One of the possible reasons of modest
clinical efficacy could be loss or down-regulation of HLA class I
molecules on the tumor cells (Cormier et al., (1998) Int. J.
Cancer. 75: 517-24., Paschen et al., (2003) Int. J. Cancer. 103:
759-67., Fonteneau et al., (1997). J. Immuol. 159: 2831-9.,
Reynolds et al., (1998) J. Immunol. 161: 6970-6.). The frequency of
tumors showing some alteration in expression of HLA class I
molecules has been estimated to be more than 40% (Cormier et al.,
(1998) Int. J. Cancer. 75: 517-24., Paschen et al., (2003) Int. J.
Cancer. 103: 759-67.). Thus, significant portion of tumor cells
could escape from the CTLs specific to the class I-epitope, even if
CTLs could be successfully induced by cancer vaccine targeting
tumor cells themselves. These problems can be overcome with the
development of effective vaccine against tumor angiogenesis, since
endothelial cells are genetically stable, do not show
down-regulation of HLA Class I molecules, and are critically
involved in the progression of a variety of tumors. Furthermore,
the CTLs could directly cause damage to the endothelial cells
without penetrating any other tissue, and lysis of even low numbers
of endothelial cells within tumor vasculature will result in
destruction of vessel integrity leading to inhibition of large
numbers of tumor cells (Folkman, J. (1995) Nat. Med. 1: 27-31.).
Therefore, endothelial cells are a good target for cancer
immunotherapy. To specifically and efficiently prevent
tumor-angiogenesis with CTL response, the appropriated target needs
to be selected among the molecules related to angiogenesis.
[0101] The results presented here, in vitro and in vivo,
demonstrate that VEGFR1 can be used as target of immunological
therapy using cellular immunity and support the definitive
rationale of the clinical development of this strategy against a
broad range of cancers.
INDUSTRIAL APPLICABILITY
[0102] The present invention provides novel peptides, which induce
cytotoxic T cells by targeting endothelial cells formed in a wide
range of tumor tissues, and are extremely effective as cancer
vaccines. The present invention also provides immunogenic
compositions comprising these peptides for treating and preventing
tumors.
[0103] While the invention has been described in detail and with
reference to specific embodiments thereof, it will be apparent to
one skilled in the art that various changes and modifications can
be made therein without departing from the spirit and scope of the
invention.
Sequence CWU 1
1
4519PRTArtificial Sequencesynthetic vascular endothelial growth
factor receptor 1 (VEGFR1, Flt-1) epitope peptide binding
HLA-A*0201 with high cytotoxic T lymphocyte (CTL) inducibility 1Val
Leu Leu Trp Glu Ile Phe Ser Leu1 5 29PRTArtificial
Sequencesynthetic vascular endothelial growth factor receptor 1
(VEGFR1, Flt-1) epitope peptide binding HLA-A*0201 with high
cytotoxic T lymphocyte (CTL) inducibility 2Thr Leu Phe Trp Leu Leu
Leu Thr Leu1 5 39PRTArtificial Sequencesynthetic vascular
endothelial growth factor receptor 1 (VEGFR1, Flt-1) epitope
peptide binding HLA-A*0201 3Ile Leu Leu Ser Glu Asn Asn Val Val1 5
49PRTArtificial Sequencesynthetic vascular endothelial growth
factor receptor 1 (VEGFR1, Flt-1) epitope peptide binding
HLA-A*0201 4Cys Val Ala Ala Thr Leu Phe Trp Leu1 5 59PRTArtificial
Sequencesynthetic vascular endothelial growth factor receptor 1
(VEGFR1, Flt-1) epitope peptide binding HLA-A*0201 5Ala Leu Met Thr
Glu Leu Lys Ile Leu1 5 69PRTArtificial Sequencesynthetic vascular
endothelial growth factor receptor 1 (VEGFR1, Flt-1) epitope
peptide binding HLA-A*0201 6Lys Met Leu Lys Glu Gly Ala Thr Ala1 5
79PRTArtificial Sequencesynthetic vascular endothelial growth
factor receptor 1 (VEGFR1, Flt-1) epitope peptide binding
HLA-A*0201 7Leu Met Thr Glu Leu Lys Ile Leu Thr1 5 89PRTArtificial
Sequencesynthetic vascular endothelial growth factor receptor 1
(VEGFR1, Flt-1) epitope peptide binding HLA-A*0201 8Ile Leu Thr His
Ile Gly His His Leu1 5 99PRTArtificial Sequencesynthetic vascular
endothelial growth factor receptor 1 (VEGFR1, Flt-1) epitope
peptide binding HLA-A*0201 9Asn Ile Leu Leu Ser Glu Asn Asn Val1 5
109PRTArtificial Sequencesynthetic vascular endothelial growth
factor receptor 1 (VEGFR1, Flt-1) epitope peptide binding
HLA-A*0201 10Tyr Leu Thr His Arg Gln Thr Asn Thr1 5
1110PRTArtificial Sequencesynthetic vascular endothelial growth
factor receptor 1 (VEGFR1, Flt-1) epitope peptide binding
HLA-A*0201 11Lys Leu Gly Asp Leu Leu Gln Ala Asn Val1 5 10
1210PRTArtificial Sequencesynthetic vascular endothelial growth
factor receptor 1 (VEGFR1, Flt-1) epitope peptide binding
HLA-A*0201 12Leu Leu Ser Glu Asn Asn Val Val Lys Ile1 5 10
1310PRTArtificial Sequencesynthetic vascular endothelial growth
factor receptor 1 (VEGFR1, Flt-1) epitope peptide binding
HLA-A*0201 with high cytotoxic T lymphocyte (CTL) inducibility
13Asn Leu Thr Ala Thr Leu Ile Val Asn Val1 5 10 1410PRTArtificial
Sequencesynthetic vascular endothelial growth factor receptor 1
(VEGFR1, Flt-1) epitope peptide binding HLA-A*0201 14Ser Leu Gly
Gly Ser Pro Tyr Pro Gly Val1 5 10 1510PRTArtificial
Sequencesynthetic vascular endothelial growth factor receptor 1
(VEGFR1, Flt-1) epitope peptide binding HLA-A*0201 15Gln Met Asp
Glu Asp Phe Cys Ser Arg Leu1 5 10 1610PRTArtificial
Sequencesynthetic vascular endothelial growth factor receptor 1
(VEGFR1, Flt-1) epitope peptide binding HLA-A*0201 16Gly Val Leu
Leu Trp Glu Ile Phe Ser Leu1 5 10 1710PRTArtificial
Sequencesynthetic vascular endothelial growth factor receptor 1
(VEGFR1, Flt-1) epitope peptide binding HLA-A*0201 17Ile Ile Met
Asp Pro Asp Glu Val Pro Leu1 5 10 1810PRTArtificial
Sequencesynthetic vascular endothelial growth factor receptor 1
(VEGFR1, Flt-1) epitope peptide binding HLA-A*0201 18Phe Gln Val
Ala Arg Gly Met Glu Phe Leu1 5 10 1910PRTArtificial
Sequencesynthetic vascular endothelial growth factor receptor 1
(VEGFR1, Flt-1) epitope peptide binding HLA-A*0201 19Tyr Leu Thr
His Arg Gln Thr Asn Thr Ile1 5 10 2010PRTArtificial
Sequencesynthetic vascular endothelial growth factor receptor 1
(VEGFR1, Flt-1) epitope peptide binding HLA-A*0201 20Ile Leu Leu
Arg Thr Val Asn Asn Arg Thr1 5 10 219PRTArtificial
Sequencesynthetic vascular endothelial growth factor receptor 1
(VEGFR1, Flt-1) epitope peptide binding HLA-A*2402 21Lys Tyr Gly
Asn Leu Ser Asn Tyr Leu1 5 229PRTArtificial Sequencesynthetic
vascular endothelial growth factor receptor 1 (VEGFR1, Flt-1)
epitope peptide binding HLA-A*2402 22Asn Tyr Leu Lys Ser Lys Arg
Asp Leu1 5 239PRTArtificial Sequencesynthetic vascular endothelial
growth factor receptor 1 (VEGFR1, Flt-1) epitope peptide binding
HLA-A*2402 23Glu Tyr Lys Ala Leu Met Thr Glu Leu1 5
249PRTArtificial Sequencesynthetic vascular endothelial growth
factor receptor 1 (VEGFR1, Flt-1) epitope peptide binding
HLA-A*2402 24Arg Tyr Val Asn Ala Phe Lys Phe Met1 5
259PRTArtificial Sequencesynthetic vascular endothelial growth
factor receptor 1 (VEGFR1, Flt-1) epitope peptide binding
HLA-A*2402 25Ser Tyr Gly Val Leu Leu Trp Glu Ile1 5
269PRTArtificial Sequencesynthetic vascular endothelial growth
factor receptor 1 (VEGFR1, Flt-1) epitope peptide binding
HLA-A*2402 26Arg Phe Ala Glu Leu Val Glu Lys Leu1 5
279PRTArtificial Sequencesynthetic vascular endothelial growth
factor receptor 1 (VEGFR1, Flt-1) epitope peptide binding
HLA-A*2402 27Glu Phe Ala Arg Glu Arg Leu Lys Leu1 5
289PRTArtificial Sequencesynthetic vascular endothelial growth
factor receptor 1 (VEGFR1, Flt-1) epitope peptide binding
HLA-A*2402 28Lys Ser Asn Leu Glu Leu Ile Thr Leu1 5
299PRTArtificial Sequencesynthetic vascular endothelial growth
factor receptor 1 (VEGFR1, Flt-1) epitope peptide binding
HLA-A*2402 29Lys Trp Glu Phe Ala Arg Glu Arg Leu1 5
309PRTArtificial Sequencesynthetic vascular endothelial growth
factor receptor 1 (VEGFR1, Flt-1) epitope peptide binding
HLA-A*2402 30Pro Tyr Asp Ala Ser Lys Trp Glu Phe1 5
3110PRTArtificial Sequencesynthetic vascular endothelial growth
factor receptor 1 (VEGFR1, Flt-1) epitope peptide binding
HLA-A*2402 31Asn Tyr Leu Lys Ser Lys Arg Asp Leu Phe1 5 10
3210PRTArtificial Sequencesynthetic vascular endothelial growth
factor receptor 1 (VEGFR1, Flt-1) epitope peptide binding
HLA-A*2402 with high cytotoxic T lymphocyte (CTL) inducibility
32Ser Tyr Gly Val Leu Leu Trp Glu Ile Phe1 5 10 3310PRTArtificial
Sequencesynthetic vascular endothelial growth factor receptor 1
(VEGFR1, Flt-1) epitope peptide binding HLA-A*2402 33Ser Tyr Ser
Phe Gln Val Ala Arg Gly Met1 5 10 3410PRTArtificial
Sequencesynthetic vascular endothelial growth factor receptor 1
(VEGFR1, Flt-1) epitope peptide binding HLA-A*2402 34Lys Ile Leu
Thr His Ile Gly His His Leu1 5 10 3510PRTArtificial
Sequencesynthetic vascular endothelial growth factor receptor 1
(VEGFR1, Flt-1) epitope peptide binding HLA-A*2402 35Ser Phe Gln
Val Ala Arg Gly Met Glu Phe1 5 10 3610PRTArtificial
Sequencesynthetic vascular endothelial growth factor receptor 1
(VEGFR1, Flt-1) epitope peptide binding HLA-A*2402 36Arg Tyr Val
Asn Ala Phe Lys Phe Met Ser1 5 10 3710PRTArtificial
Sequencesynthetic vascular endothelial growth factor receptor 1
(VEGFR1, Flt-1) epitope peptide binding HLA-A*2402 37Lys Ile Gln
Gln Glu Pro Gly Ile Ile Leu1 5 10 3810PRTArtificial
Sequencesynthetic vascular endothelial growth factor receptor 1
(VEGFR1, Flt-1) epitope peptide binding HLA-A*2402 38Lys Ala Leu
Met Thr Glu Leu Lys Ile Leu1 5 10 3910PRTArtificial
Sequencesynthetic vascular endothelial growth factor receptor 1
(VEGFR1, Flt-1) epitope peptide binding HLA-A*2402 39Glu Leu Val
Glu Lys Leu Gly Asp Leu Leu1 5 10 409PRTArtificial
Sequencesynthetic vascular endothelial growth factor receptor 1
(VEGFR1, Flt-1) epitope peptide binding HLA-A*2402 40Lys Ser Asp
Val Trp Ser Tyr Gly Val1 5 4110PRTArtificial Sequencesynthetic CEA
peptide positive control 41Asp Val Leu Tyr Gly Pro Asp Thr Pro Ile1
5 10 429PRTArtificial Sequencesynthetic CMV peptide A02 positive
control 42Asn Leu Val Pro Met Val Ala Thr Val1 5 439PRTArtificial
Sequencesynthetic CMV peptide A24 positive control 43Gln Tyr Asp
Pro Val Ala Ala Leu Phe1 5 445777DNAHomo sapiensvascular
endothelial growth factor receptor 1 (VEGFR1, Flt-1) 44gcggacactc
ctctcggctc ctccccggca gcggcggcgg ctcggagcgg gctccggggc 60tcgggtgcag
cggccagcgg gcctggcggc gaggattacc cggggaagtg gttgtctcct
120ggctggagcc gcgagacggg cgctcagggc gcggggccgg cggcggcgaa
cgagaggacg 180gactctggcg gccgggtcgt tggccggggg agcgcgggca
ccgggcgagc aggccgcgtc 240gcgctcacca tggtcagcta ctgggacacc
ggggtcctgc tgtgcgcgct gctcagctgt 300ctgcttctca caggatctag
ttcaggttca aaattaaaag atcctgaact gagtttaaaa 360ggcacccagc
acatcatgca agcaggccag acactgcatc tccaatgcag gggggaagca
420gcccataaat ggtctttgcc tgaaatggtg agtaaggaaa gcgaaaggct
gagcataact 480aaatctgcct gtggaagaaa tggcaaacaa ttctgcagta
ctttaacctt gaacacagct 540caagcaaacc acactggctt ctacagctgc
aaatatctag ctgtacctac ttcaaagaag 600aaggaaacag aatctgcaat
ctatatattt attagtgata caggtagacc tttcgtagag 660atgtacagtg
aaatccccga aattatacac atgactgaag gaagggagct cgtcattccc
720tgccgggtta cgtcacctaa catcactgtt actttaaaaa agtttccact
tgacactttg 780atccctgatg gaaaacgcat aatctgggac agtagaaagg
gcttcatcat atcaaatgca 840acgtacaaag aaatagggct tctgacctgt
gaagcaacag tcaatgggca tttgtataag 900acaaactatc tcacacatcg
acaaaccaat acaatcatag atgtccaaat aagcacacca 960cgcccagtca
aattacttag aggccatact cttgtcctca attgtactgc taccactccc
1020ttgaacacga gagttcaaat gacctggagt taccctgatg aaaaaaataa
gagagcttcc 1080gtaaggcgac gaattgacca aagcaattcc catgccaaca
tattctacag tgttcttact 1140attgacaaaa tgcagaacaa agacaaagga
ctttatactt gtcgtgtaag gagtggacca 1200tcattcaaat ctgttaacac
ctcagtgcat atatatgata aagcattcat cactgtgaaa 1260catcgaaaac
agcaggtgct tgaaaccgta gctggcaagc ggtcttaccg gctctctatg
1320aaagtgaagg catttccctc gccggaagtt gtatggttaa aagatgggtt
acctgcgact 1380gagaaatctg ctcgctattt gactcgtggc tactcgttaa
ttatcaagga cgtaactgaa 1440gaggatgcag ggaattatac aatcttgctg
agcataaaac agtcaaatgt gtttaaaaac 1500ctcactgcca ctctaattgt
caatgtgaaa ccccagattt acgaaaaggc cgtgtcatcg 1560tttccagacc
cggctctcta cccactgggc agcagacaaa tcctgacttg taccgcatat
1620ggtatccctc aacctacaat caagtggttc tggcacccct gtaaccataa
tcattccgaa 1680gcaaggtgtg acttttgttc caataatgaa gagtccttta
tcctggatgc tgacagcaac 1740atgggaaaca gaattgagag catcactcag
cgcatggcaa taatagaagg aaagaataag 1800atggctagca ccttggttgt
ggctgactct agaatttctg gaatctacat ttgcatagct 1860tccaataaag
ttgggactgt gggaagaaac ataagctttt atatcacaga tgtgccaaat
1920gggtttcatg ttaacttgga aaaaatgccg acggaaggag aggacctgaa
actgtcttgc 1980acagttaaca agttcttata cagagacgtt acttggattt
tactgcggac agttaataac 2040agaacaatgc actacagtat tagcaagcaa
aaaatggcca tcactaagga gcactccatc 2100actcttaatc ttaccatcat
gaatgtttcc ctgcaagatt caggcaccta tgcctgcaga 2160gccaggaatg
tatacacagg ggaagaaatc ctccagaaga aagaaattac aatcagagat
2220caggaagcac catacctcct gcgaaacctc agtgatcaca cagtggccat
cagcagttcc 2280accactttag actgtcatgc taatggtgtc cccgagcctc
agatcacttg gtttaaaaac 2340aaccacaaaa tacaacaaga gcctggaatt
attttaggac caggaagcag cacgctgttt 2400attgaaagag tcacagaaga
ggatgaaggt gtctatcact gcaaagccac caaccagaag 2460ggctctgtgg
aaagttcagc atacctcact gttcaaggaa cctcggacaa gtctaatctg
2520gagctgatca ctctaacatg cacctgtgtg gctgcgactc tcttctggct
cctattaacc 2580ctccttatcc gaaaaatgaa aaggtcttct tctgaaataa
agactgacta cctatcaatt 2640ataatggacc cagatgaagt tcctttggat
gagcagtgtg agcggctccc ttatgatgcc 2700agcaagtggg agtttgcccg
ggagagactt aaactgggca aatcacttgg aagaggggct 2760tttggaaaag
tggttcaagc atcagcattt ggcattaaga aatcacctac gtgccggact
2820gtggctgtga aaatgctgaa agagggggcc acggccagcg agtacaaagc
tctgatgact 2880gagctaaaaa tcttgaccca cattggccac catctgaacg
tggttaacct gctgggagcc 2940tgcaccaagc aaggagggcc tctgatggtg
attgttgaat actgcaaata tggaaatctc 3000tccaactacc tcaagagcaa
acgtgactta ttttttctca acaaggatgc agcactacac 3060atggagccta
agaaagaaaa aatggagcca ggcctggaac aaggcaagaa accaagacta
3120gatagcgtca ccagcagcga aagctttgcg agctccggct ttcaggaaga
taaaagtctg 3180agtgatgttg aggaagagga ggattctgac ggtttctaca
aggagcccat cactatggaa 3240gatctgattt cttacagttt tcaagtggcc
agaggcatgg agttcctgtc ttccagaaag 3300tgcattcatc gggacctggc
agcgagaaac attcttttat ctgagaacaa cgtggtgaag 3360atttgtgatt
ttggccttgc ccgggatatt tataagaacc ccgattatgt gagaaaagga
3420gatactcgac ttcctctgaa atggatggct cccgaatcta tctttgacaa
aatctacagc 3480accaagagcg acgtgtggtc ttacggagta ttgctgtggg
aaatcttctc cttaggtggg 3540tctccatacc caggagtaca aatggatgag
gacttttgca gtcgcctgag ggaaggcatg 3600aggatgagag ctcctgagta
ctctactcct gaaatctatc agatcatgct ggactgctgg 3660cacagagacc
caaaagaaag gccaagattt gcagaacttg tggaaaaact aggtgatttg
3720cttcaagcaa atgtacaaca ggatggtaaa gactacatcc caatcaatgc
catactgaca 3780ggaaatagtg ggtttacata ctcaactcct gccttctctg
aggacttctt caaggaaagt 3840atttcagctc cgaagtttaa ttcaggaagc
tctgatgatg tcagatatgt aaatgctttc 3900aagttcatga gcctggaaag
aatcaaaacc tttgaagaac ttttaccgaa tgccacctcc 3960atgtttgatg
actaccaggg cgacagcagc actctgttgg cctctcccat gctgaagcgc
4020ttcacctgga ctgacagcaa acccaaggcc tcgctcaaga ttgacttgag
agtaaccagt 4080aaaagtaagg agtcggggct gtctgatgtc agcaggccca
gtttctgcca ttccagctgt 4140gggcacgtca gcgaaggcaa gcgcaggttc
acctacgacc acgctgagct ggaaaggaaa 4200atcgcgtgct gctccccgcc
cccagactac aactcggtgg tcctgtactc caccccaccc 4260atctagagtt
tgacacgaag ccttatttct agaagcacat gtgtatttat acccccagga
4320aactagcttt tgccagtatt atgcatatat aagtttacac ctttatcttt
ccatgggagc 4380cagctgcttt ttgtgatttt tttaatagtg cttttttttt
ttgactaaca agaatgtaac 4440tccagataga gaaatagtga caagtgaaga
acactactgc taaatcctca tgttactcag 4500tgttagagaa atccttccta
aacccaatga cttccctgct ccaacccccg ccacctcagg 4560gcacgcagga
ccagtttgat tgaggagctg cactgatcac ccaatgcatc acgtacccca
4620ctgggccagc cctgcagccc aaaacccagg gcaacaagcc cgttagcccc
aggggatcac 4680tggctggcct gagcaacatc tcgggagtcc tctagcaggc
ctaagacatg tgaggaggaa 4740aaggaaaaaa agcaaaaagc aagggagaaa
agagaaaccg ggagaaggca tgagaaagaa 4800tttgagacgc accatgtggg
cacggagggg gacggggctc agcaatgcca tttcagtggc 4860ttcccagctc
tgacccttct acatttgagg gcccagccag gagcagatgg acagcgatga
4920ggggacattt tctggattct gggaggcaag aaaaggacaa atatcttttt
tggaactaaa 4980gcaaatttta gacctttacc tatggaagtg gttctatgtc
cattctcatt cgtggcatgt 5040tttgatttgt agcactgagg gtggcactca
actctgagcc catacttttg gctcctctag 5100taagatgcac tgaaaactta
gccagagtta ggttgtctcc aggccatgat ggccttacac 5160tgaaaatgtc
acattctatt ttgggtatta atatatagtc cagacactta actcaatttc
5220ttggtattat tctgttttgc acagttagtt gtgaaagaaa gctgagaaga
atgaaaatgc 5280agtcctgagg agagttttct ccatatcaaa acgagggctg
atggaggaaa aaggtcaata 5340aggtcaaggg aagaccccgt ctctatacca
accaaaccaa ttcaccaaca cagttgggac 5400ccaaaacaca ggaagtcagt
cacgtttcct tttcatttaa tggggattcc actatctcac 5460actaatctga
aaggatgtgg aagagcatta gctggcgcat attaagcact ttaagctcct
5520tgagtaaaaa ggtggtatgt aatttatgca aggtatttct ccagttggga
ctcaggatat 5580tagttaatga gccatcacta gaagaaaagc ccattttcaa
ctgctttgaa acttgcctgg 5640ggtctgagca tgatgggaat agggagacag
ggtaggaaag ggcgcctact cttcagggtc 5700taaagatcaa gtgggccttg
gatcgctaag ctggctctgt ttgatgctat ttatgcaagt 5760tagggtctat gtattta
5777451338PRTHomo sapiensvascular endothelial growth factor
receptor 1 (VEGFR1, Flt-1) 45Met Val Ser Tyr Trp Asp Thr Gly Val
Leu Leu Cys Ala Leu Leu Ser1 5 10 15 Cys Leu Leu Leu Thr Gly Ser
Ser Ser Gly Ser Lys Leu Lys Asp Pro 20 25 30 Glu Leu Ser Leu Lys
Gly Thr Gln His Ile Met Gln Ala Gly Gln Thr 35 40 45 Leu His Leu
Gln Cys Arg Gly Glu Ala Ala His Lys Trp Ser Leu Pro 50 55 60 Glu
Met Val Ser Lys Glu Ser Glu Arg Leu Ser Ile Thr Lys Ser Ala65 70 75
80 Cys Gly Arg Asn Gly Lys Gln Phe Cys Ser Thr Leu Thr Leu Asn Thr
85 90 95 Ala Gln Ala Asn His Thr Gly Phe Tyr Ser Cys Lys Tyr Leu
Ala Val 100 105 110 Pro Thr Ser Lys Lys Lys Glu Thr Glu Ser Ala Ile
Tyr Ile Phe Ile 115 120 125 Ser Asp Thr Gly Arg Pro Phe Val Glu Met
Tyr Ser Glu Ile Pro Glu 130 135 140 Ile Ile His Met Thr Glu Gly Arg
Glu Leu Val Ile Pro Cys Arg Val145 150 155 160 Thr Ser Pro Asn Ile
Thr Val Thr Leu Lys Lys Phe Pro Leu Asp Thr 165
170 175 Leu Ile Pro Asp Gly Lys Arg Ile Ile Trp Asp Ser Arg Lys Gly
Phe 180 185 190 Ile Ile Ser Asn Ala Thr Tyr Lys Glu Ile Gly Leu Leu
Thr Cys Glu 195 200 205 Ala Thr Val Asn Gly His Leu Tyr Lys Thr Asn
Tyr Leu Thr His Arg 210 215 220 Gln Thr Asn Thr Ile Ile Asp Val Gln
Ile Ser Thr Pro Arg Pro Val225 230 235 240 Lys Leu Leu Arg Gly His
Thr Leu Val Leu Asn Cys Thr Ala Thr Thr 245 250 255 Pro Leu Asn Thr
Arg Val Gln Met Thr Trp Ser Tyr Pro Asp Glu Lys 260 265 270 Asn Lys
Arg Ala Ser Val Arg Arg Arg Ile Asp Gln Ser Asn Ser His 275 280 285
Ala Asn Ile Phe Tyr Ser Val Leu Thr Ile Asp Lys Met Gln Asn Lys 290
295 300 Asp Lys Gly Leu Tyr Thr Cys Arg Val Arg Ser Gly Pro Ser Phe
Lys305 310 315 320 Ser Val Asn Thr Ser Val His Ile Tyr Asp Lys Ala
Phe Ile Thr Val 325 330 335 Lys His Arg Lys Gln Gln Val Leu Glu Thr
Val Ala Gly Lys Arg Ser 340 345 350 Tyr Arg Leu Ser Met Lys Val Lys
Ala Phe Pro Ser Pro Glu Val Val 355 360 365 Trp Leu Lys Asp Gly Leu
Pro Ala Thr Glu Lys Ser Ala Arg Tyr Leu 370 375 380 Thr Arg Gly Tyr
Ser Leu Ile Ile Lys Asp Val Thr Glu Glu Asp Ala385 390 395 400 Gly
Asn Tyr Thr Ile Leu Leu Ser Ile Lys Gln Ser Asn Val Phe Lys 405 410
415 Asn Leu Thr Ala Thr Leu Ile Val Asn Val Lys Pro Gln Ile Tyr Glu
420 425 430 Lys Ala Val Ser Ser Phe Pro Asp Pro Ala Leu Tyr Pro Leu
Gly Ser 435 440 445 Arg Gln Ile Leu Thr Cys Thr Ala Tyr Gly Ile Pro
Gln Pro Thr Ile 450 455 460 Lys Trp Phe Trp His Pro Cys Asn His Asn
His Ser Glu Ala Arg Cys465 470 475 480 Asp Phe Cys Ser Asn Asn Glu
Glu Ser Phe Ile Leu Asp Ala Asp Ser 485 490 495 Asn Met Gly Asn Arg
Ile Glu Ser Ile Thr Gln Arg Met Ala Ile Ile 500 505 510 Glu Gly Lys
Asn Lys Met Ala Ser Thr Leu Val Val Ala Asp Ser Arg 515 520 525 Ile
Ser Gly Ile Tyr Ile Cys Ile Ala Ser Asn Lys Val Gly Thr Val 530 535
540 Gly Arg Asn Ile Ser Phe Tyr Ile Thr Asp Val Pro Asn Gly Phe
His545 550 555 560 Val Asn Leu Glu Lys Met Pro Thr Glu Gly Glu Asp
Leu Lys Leu Ser 565 570 575 Cys Thr Val Asn Lys Phe Leu Tyr Arg Asp
Val Thr Trp Ile Leu Leu 580 585 590 Arg Thr Val Asn Asn Arg Thr Met
His Tyr Ser Ile Ser Lys Gln Lys 595 600 605 Met Ala Ile Thr Lys Glu
His Ser Ile Thr Leu Asn Leu Thr Ile Met 610 615 620 Asn Val Ser Leu
Gln Asp Ser Gly Thr Tyr Ala Cys Arg Ala Arg Asn625 630 635 640 Val
Tyr Thr Gly Glu Glu Ile Leu Gln Lys Lys Glu Ile Thr Ile Arg 645 650
655 Asp Gln Glu Ala Pro Tyr Leu Leu Arg Asn Leu Ser Asp His Thr Val
660 665 670 Ala Ile Ser Ser Ser Thr Thr Leu Asp Cys His Ala Asn Gly
Val Pro 675 680 685 Glu Pro Gln Ile Thr Trp Phe Lys Asn Asn His Lys
Ile Gln Gln Glu 690 695 700 Pro Gly Ile Ile Leu Gly Pro Gly Ser Ser
Thr Leu Phe Ile Glu Arg705 710 715 720 Val Thr Glu Glu Asp Glu Gly
Val Tyr His Cys Lys Ala Thr Asn Gln 725 730 735 Lys Gly Ser Val Glu
Ser Ser Ala Tyr Leu Thr Val Gln Gly Thr Ser 740 745 750 Asp Lys Ser
Asn Leu Glu Leu Ile Thr Leu Thr Cys Thr Cys Val Ala 755 760 765 Ala
Thr Leu Phe Trp Leu Leu Leu Thr Leu Leu Ile Arg Lys Met Lys 770 775
780 Arg Ser Ser Ser Glu Ile Lys Thr Asp Tyr Leu Ser Ile Ile Met
Asp785 790 795 800 Pro Asp Glu Val Pro Leu Asp Glu Gln Cys Glu Arg
Leu Pro Tyr Asp 805 810 815 Ala Ser Lys Trp Glu Phe Ala Arg Glu Arg
Leu Lys Leu Gly Lys Ser 820 825 830 Leu Gly Arg Gly Ala Phe Gly Lys
Val Val Gln Ala Ser Ala Phe Gly 835 840 845 Ile Lys Lys Ser Pro Thr
Cys Arg Thr Val Ala Val Lys Met Leu Lys 850 855 860 Glu Gly Ala Thr
Ala Ser Glu Tyr Lys Ala Leu Met Thr Glu Leu Lys865 870 875 880 Ile
Leu Thr His Ile Gly His His Leu Asn Val Val Asn Leu Leu Gly 885 890
895 Ala Cys Thr Lys Gln Gly Gly Pro Leu Met Val Ile Val Glu Tyr Cys
900 905 910 Lys Tyr Gly Asn Leu Ser Asn Tyr Leu Lys Ser Lys Arg Asp
Leu Phe 915 920 925 Phe Leu Asn Lys Asp Ala Ala Leu His Met Glu Pro
Lys Lys Glu Lys 930 935 940 Met Glu Pro Gly Leu Glu Gln Gly Lys Lys
Pro Arg Leu Asp Ser Val945 950 955 960 Thr Ser Ser Glu Ser Phe Ala
Ser Ser Gly Phe Gln Glu Asp Lys Ser 965 970 975 Leu Ser Asp Val Glu
Glu Glu Glu Asp Ser Asp Gly Phe Tyr Lys Glu 980 985 990 Pro Ile Thr
Met Glu Asp Leu Ile Ser Tyr Ser Phe Gln Val Ala Arg 995 1000 1005
Gly Met Glu Phe Leu Ser Ser Arg Lys Cys Ile His Arg Asp Leu Ala
1010 1015 1020 Ala Arg Asn Ile Leu Leu Ser Glu Asn Asn Val Val Lys
Ile Cys Asp1025 1030 1035 1040Phe Gly Leu Ala Arg Asp Ile Tyr Lys
Asn Pro Asp Tyr Val Arg Lys 1045 1050 1055 Gly Asp Thr Arg Leu Pro
Leu Lys Trp Met Ala Pro Glu Ser Ile Phe 1060 1065 1070 Asp Lys Ile
Tyr Ser Thr Lys Ser Asp Val Trp Ser Tyr Gly Val Leu 1075 1080 1085
Leu Trp Glu Ile Phe Ser Leu Gly Gly Ser Pro Tyr Pro Gly Val Gln
1090 1095 1100 Met Asp Glu Asp Phe Cys Ser Arg Leu Arg Glu Gly Met
Arg Met Arg1105 1110 1115 1120Ala Pro Glu Tyr Ser Thr Pro Glu Ile
Tyr Gln Ile Met Leu Asp Cys 1125 1130 1135 Trp His Arg Asp Pro Lys
Glu Arg Pro Arg Phe Ala Glu Leu Val Glu 1140 1145 1150 Lys Leu Gly
Asp Leu Leu Gln Ala Asn Val Gln Gln Asp Gly Lys Asp 1155 1160 1165
Tyr Ile Pro Ile Asn Ala Ile Leu Thr Gly Asn Ser Gly Phe Thr Tyr
1170 1175 1180 Ser Thr Pro Ala Phe Ser Glu Asp Phe Phe Lys Glu Ser
Ile Ser Ala1185 1190 1195 1200Pro Lys Phe Asn Ser Gly Ser Ser Asp
Asp Val Arg Tyr Val Asn Ala 1205 1210 1215 Phe Lys Phe Met Ser Leu
Glu Arg Ile Lys Thr Phe Glu Glu Leu Leu 1220 1225 1230 Pro Asn Ala
Thr Ser Met Phe Asp Asp Tyr Gln Gly Asp Ser Ser Thr 1235 1240 1245
Leu Leu Ala Ser Pro Met Leu Lys Arg Phe Thr Trp Thr Asp Ser Lys
1250 1255 1260 Pro Lys Ala Ser Leu Lys Ile Asp Leu Arg Val Thr Ser
Lys Ser Lys1265 1270 1275 1280Glu Ser Gly Leu Ser Asp Val Ser Arg
Pro Ser Phe Cys His Ser Ser 1285 1290 1295 Cys Gly His Val Ser Glu
Gly Lys Arg Arg Phe Thr Tyr Asp His Ala 1300 1305 1310 Glu Leu Glu
Arg Lys Ile Ala Cys Cys Ser Pro Pro Pro Asp Tyr Asn 1315 1320 1325
Ser Val Val Leu Tyr Ser Thr Pro Pro Ile 1330 1335
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