Tumor antigen peptides originating in cyclophilin B Number:7,041,297 from the United States Patent and Trademark Office (PTO) owispatent Tumor antigen peptides derived from cyclophilins or derivatives thereof having the functionally equivalent properties; medicaments, prophylactics, or diagnostics for tumors comprising as an active ingredient such tumor antigen peptides or derivatives thereof, cyclophilins or partial polypeptides thereof, or genes encoding said cyclophilins or partial polypeptides thereof; in vitro use of the above substances for treatment of tumors; and antibodies against the above tumor antigen peptides derived from cyclophilins or derivatives thereof are provided.<H cyclophilin, originating, Tumor, antigen, p, 7041297.html, Patent, pto, 7041297

Title: Tumor antigen peptides originating in cyclophilin B

Abstract: Tumor antigen peptides derived from cyclophilins or derivatives thereof having the functionally equivalent properties; medicaments, prophylactics, or diagnostics for tumors comprising as an active ingredient such tumor antigen peptides or derivatives thereof, cyclophilins or partial polypeptides thereof, or genes encoding said cyclophilins or partial polypeptides thereof; in vitro use of the above substances for treatment of tumors; and antibodies against the above tumor antigen peptides derived from cyclophilins or derivatives thereof are provided.

Patent Number: 7,041,297 Issued on 05/09/2006 to Itoh, et al.

Inventors: Itoh; Kyogo (Saga-ken, JP); Gomi; Shinya (Soja, JP)
Assignee: Sumitomo Pharmaceuticals Company (Osaka, JP)
Kyogo ITOH (Saga-Ken, JP)

Appl. No.: 720469

Filed: June 24, 1999

PCT Filed: June 24, 1999

PCT NO: PCT/JP99/03360

371 Date: December 22, 2000

PCT PUB.NO.: WO99/67288

PCT PUB. Date: December 29, 1999

Foreign Application Priority Data


Jun 25, 1998 [JP]			10/178449

Current U.S. Class: 424/185.1 ; 530/300

Current International Class: A61K 39/00 (20060101); C07K 5/00 (20060101)

Field of Search: 530/35,403,412,350,328,327,300 424/185.1,184.1,193.1 514/15,14,16

References Cited [Referenced By]

U.S. Patent Documents


5837248	November 1998	Kikuchi et al.
5840839	November 1998	Wang et al.

Foreign Patent Documents


0 326 067	Aug., 1989	EP
0 326 067	Aug., 1989	EP
WO94/03205	Feb., 1994	WO

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Primary Examiner: Yu; Misook
Attorney, Agent or Firm: Birch, Stewart, Kolasch & Birch, LLP

Claims

What is claimed is:

1. An isolated tumor antigen peptide of 9 11 amino acids in length, which comprises a sequence selected from the group consisting of: SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 39, SEQ ID NO: 40, SEQ ID NO: 41, SEQ ID NO: 42, and SEQ ID NO: 43, and which binds to HLA-A24 antigen and is recognized by cytotoxic T lymphocytes.

2. An isolated tumor antigen peptide of 9 11 amino acids in length comprising a variant of a sequence selected from the group consisting of: SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 41, SEQ ID NO: 42, and SEQ ID NO: 43, wherein the amino acid residue located at position 2 in said SEQ ID NO: 1, 2, 41, 42, or 43 is substituted by tyrosine, phenylalanine, methionine, or tryptophan, and/or the amino acid residue located at the C-terminus position in said SEQ ID NO: 1, 2, 41, 42, or 43 is substituted by phenylalanine, leucine, isoleucine, tryptophan, or methionine, and wherein said peptide binds to HLA-A24 antigen and is recognized by cytotoxic T lymphocytes.

3. A composition comprising as an active ingredient at least one of substances selected from tumor antigen peptides according to any one of claims 1 or 2.

Description

This application is the national phase under 35 U.S.C. .sctn. 371 of PCT International Application No. PCT/JP99/03360 which has an International filing date of Jun. 24, 1999, which designated the United States of America.

TECHNICAL FIELD

The present invention relates to novel tumor antigen peptides derived from a cyclophilin and related substances. More particularly, it relates to tumor antigen peptides derived from cyclophilin B and derivatives thereof having the functionally equivalent properties, and further to medicaments, prophylactics, or diagnostics for tumors that utilize in vivo or in vitro such tumor antigen peptides, derivatives thereof, cyclophilin B polypeptides, or genes therefor.

BACKGROUND ART

It is known that immune system, particularly T cells, plays an important role in tumor elimination by a living body. Indeed, infiltration of lymphocytes exhibiting cytotoxic effects on tumor cells in human tumor foci has been observed (Arch. Surg., 126:200, 1990), and cytotoxic T lymphocytes (CTLs) recognizing autologous tumor cells have been isolated from melanomas without great difficulties (e.g., Immunol. Today, 8:385, 1987; J. Immunol., 138:989, 1987; and Int. J. Cancer, 52:52, 1992). In addition, the results of clinical treatment of melanomas by transfer of the CTLs recognizing antologous tumor cells also suggest the importance of T cells in tumor elimination (J. Natl. Cancer. Inst., 86:1159, 1994).

Although it had long been unknown about target molecules for CTLs attacking autologous tumor cells, the recent advance in immunology and molecular biology gradually began elucidating such target molecules. Specifically, it has been found that CTL, using the T cell receptors (TCRs), recognizes a complex between a peptide, called tumor antigen peptide, and a major histocompatibility complex class I antigen (MHC class I antigen, and in the case of human, referred to as HLA antigen), and thereby attacks autologous tumor cells.

Tumor antigen peptides are generated by degradation of proteins specific for tumors, that is, tumor antigen proteins in cells with proteasomes, which proteins are intracellularly synthesized. The tumor antigen peptides thus generated bind to MHC class I antigens (HLA antigens) in endoplasmic reticulum to form complexes and the complexes are transported to the cell surface to be presented as an antigen. A tumor-specific CTL recognizes the complex presented as an antigen, and exhibits anti-tumor effects through its cytotoxic action or production of lymphokines. As a consequence of elucidation of a series of the actions, it has become possible to treat tumors by using tumor antigen proteins or tumor antigen peptides as so-called cancer vaccines to enhance tumor-specific CTLs in the body of a tumor patient.

As a tumor antigen protein, T. Boon et al. identified a protein named MAGE from human melanoma cells for the first time in 1991 (Science, 254:1643, 1991). Subsequently, several additional tumor antigen proteins have been identified mainly from melanoma cells. Examples of melanoma antigens that have been identified are melanosomal proteins such as a melanocytic tissue-specific protein, gp100 (J. Exp. Med., 179:1005, 1994), MART-1 (Proc. Natl. Acad. Sci. USA, 91:3515, 1994), and tyrosinase (J. Exp. Med., 178:489, 1993), MEGE-related proteins that are expressed not only on melanomas but also on various cancer cells and normal testicular cells (J. Exp. Med., 179:921, 1994), .beta.-catenin having a tumor-specific amino acid mutation (J. Exp. Med., 183:1185, 1996), and CDK4 (Science, 269:1281, 1995). Tumor antigen proteins other than those from melanomas have also been identified, including products of oncogenes such as HER2-neu (J. Exp. Med., 181:2109, 1995) and p53 (Proc. Natl. Acad. Sci. USA, 93:14704, 1996), tumor markers such as CEA (J. Natl. Cancer Inst., 87:982, 1995) and PSA (J. Natl. Cancer Inst., 89:293, 1997), and viral proteins such as HPV (J. Immunol., 154:5934, 1995) and EBV (Int. Immunol., 7:653, 1995). Detailed descriptions of these subjects can be found in published reviews (e.g. Immunol. Today, 18:267, 1997; J. Exp. Med., 183:725, 1996; and Curr. Opin. Immunol., 8:628, 1996).

In applications of a tumor antigen protein or tumor antigen peptide to treatment or diagnosis of tumors, it is important to identify a tumor antigen that can be widely used for epithelial tumors such as gastric and lung cancers which occur at a much higher incidence compared to melanomas. In this relation, the present inventors conducted cloning of a gene encoding a novel tumor antigen protein from squamous carcinoma cells derived from esophageal cancer, and identified for the first time from tumor cells other than melanomas several tumor antigen peptides that are bound to and presented on HLA antigens of which HLA types are HLA-A24 or HLA-A26 (J. Exp. Med., 187:277, 1998; International Patent Publication WO 97/46676).

When these tumor antigen peptides are clinically applied in practice, it is desirable to use two or more different tumor antigen peptides rather than to use only a single peptide. That is to say, taking into consideration the facts that all cancer cells do not express an identical tumor antigen in common and that two or more different tumor antigen peptides are presented on a single cancer cell, a treatment using two or more different tumor antigen peptides is believed to be more effective. Indeed, in the case of melanoma, development of cocktail formulations comprising two or more peptides has been attempted, since a single peptide derived from a tumor antigen failed to exhibit adequate effects (Int. J. Cancer, 66:162, 1996; and Int. J. Cancer, 67:54, 1996). Under such circumstances, it is being required to identify novel tumor antigen proteins and tumor antigen peptides that can be widely used for epithelial tumors such as gastric and lung cancers which occur at a high incidence.

DISCLOSURE OF THE INVENTION

The present invention aims to provide novel tumor antigen peptides derived from a cyclophilin, and related substances. More particularly, it aims to provide tumor antigen peptides derived from cyclophilin B and derivatives thereof having the functionally equivalent properties as well as medicaments, prophylactics, and diagnostics for tumors that utilize in vivo or in vitro the tumor antigen peptides, the derivatives thereof, cyclophilin B polypeptides, or genes therefor.

The cyclophilin B-derived tumor antigen peptide of the present invention comprises a tumor antigen peptide that is bound to and presented on HLA-A24 and HLA-A2, which are the HLA antigens that the Japanese and Caucasians carry with a high probability, and it is also a tumor antigen peptide that can be applied to treatment or prophylaxis of a wide range of tumors including epithelial tumors such as lung cancer, bladder cancer, and osteosarcoma, and leukemias. Accordingly, cyclophilin B, the tumor antigen protein of the present invention, and a gene therefor, or tumor antigen peptides derived from cyclophilin B are expected to be useful as novel antitumor medicaments.

In order to obtain novel tumor antigen peptides and a tumor antigen protein from which said peptides are derived, the present inventors made the following attempts.

From lymphocytes of a patient with lung adenocarcinoma, the present inventors firstly established a CTL cell line that recognizes HLA-A24 or HLA-A2-positive bladder cancer, lung cancer, osteosarcoma, or leukemia cell lines, and named it KG-CTL (deposit number: FERM BP-6725).

Next, a cDNA library was prepared from bladder cancer cell line HT-1376 with which the above KG-CTL reacts strongly, and COS-7 cells were doubly transfected with a recombinant plasmid of the library and a recombinant plasmid containing HLA-A2402 (one type of HLA-A24) cDNA. The resulting transfectants were treated with the above KG-CTL, and the amount of produced IFN-.gamma. was measured to determine whether or not KG-CTL was activated. As a result of such screening repeatedly conducted, the present inventors finally succeeded in cloning a gene encoding a tumor antigen protein. Base sequencing of the gene revealed that said tumor antigen protein had the same amino acid sequence as that of a known protein, cyclophilin B.

Cyclophilin B is known to be a binding protein for an immunosuppressive agent, cyclosporin A, and to participate in activation of immunocytes. However, it has never been known prior to the present invention that it has a function as a tumor antigen.

Then, the present inventors identified tumor antigen peptide portions in the amino acid sequence of cyclophilin B that are bound to and presented on HLA-A24 and HLA-A2, and demonstrated that activity as a tumor antigen peptide resides in such peptides and derivatives thereof.

Furthermore, the present inventors demonstrated that homologs of cyclophilin B, cyclophilins A, C, and D, also have tumor antigen peptide activities similar to cyclophilin B.

The present invention has been completed on the basis of the findings as described above.

Thus, the present invention relates to:

(1) a tumor antigen peptide that is a partial peptide derived from a cyclophilin, and that is capable of binding to an HLA antigen and being recognized by cytotoxic T lymphocytes, or a derivative thereof having the functionally equivalent properties;

(2) a tumor antigen peptide that is a partial peptide derived from cyclophilin B, and that is capable of binding to an HLA antigen and being recognized by cytotoxic T lymphocytes, or a derivative thereof having the functionally equivalent properties;

(3) the tumor antigen peptide according to the above (1) or (2) wherein the HLA antigen is HLA-A24 or HLA-A2, or a derivative thereof having the functionally equivalent properties;

(4) the tumor antigen peptide according to the above (3), that is selected from sequences comprising all or part of an amino acid sequence shown in any one of SEQ ID NOs: 1 36 or SEQ ID NOs: 41 43, or a derivative thereof having the functionally equivalent properties;

(5) the tumor antigen peptide according to the above (4), that is selected from sequences comprising all or part of the amino acid sequence shown in SEQ ID NO: 1 or 2, or a derivative thereof having the functionally equivalent properties;

(6) the tumor antigen peptide derivative according to the above (4), that is selected from sequences comprising all or part of an amino acid sequence in which the amino acid residue at position 2 and/or the C-terminus in the amino acid sequence shown in any one of SEQ ID NOs: 1 36 is substituted by another amino acid residue;

(7) the tumor antigen peptide derivative according to the above (6), that is selected from sequences comprising all or part of an amino acid sequence in which the amino acid residue at position 2 and/or the C-terminus in the amino acid sequence shown in SEQ ID NO: 1 or 2 is substituted by another amino acid residue;

(8) the tumor antigen peptide derivative according to the above (6), that is selected from sequences comprising all or part of an amino acid sequence in which the amino acid residue at position 2 in the amino acid sequence shown in any one of SEQ ID NOs: 1 11 is substituted by tyrosine, phenylalanine, methionine, or tryptophan, and/or the amino acid residue at the C-terminus is substituted by phenylalanine, leucine, isoleucine, tryptophan, or methionine;

(9) the tumor antigen peptide derivative according to the above (6), that is selected from sequences comprising all or part of an amino acid sequence in which the amino acid residue at position 2 in the amino acid sequence shown in any one of SEQ ID NOs: 12 36 is substituted by leucine, methionine, valine, isoleucine, or glutamine, and/or the amino acid residue at the C-terminus is substituted by valine or leucine;

(10) the tumor antigen peptide derivative according to the above (8), that is selected from sequences comprising all or part of the amino acid sequence shown in SEQ ID NO: 37 or 38;

(11) the tumor antigen peptide derivative according to the above (10), that is selected from sequences comprising all or part of the amino acid sequence shown in SEQ ID NO: 39 or 40;

(12) a pharmaceutical composition for treating or preventing tumors, that comprises as an active ingredient at least one of substances selected from tumor antigen peptides and derivatives thereof according to any one of the above (1) (11);

(13) a pharmaceutical composition for treating or preventing tumors, that comprises as an active ingredient a cyclophilin, a partial polypeptide of the cyclophilin that comprises a tumor antigen peptide portion capable of binding to an HLA antigen and being recognized by cytotoxic T lymphocytes, or a gene encoding the cyclophilin or the partial polypeptide thereof;

(14) a pharmaceutical composition for treating or preventing tumors, that comprises as an active ingredient cyclophilin B, a partial polypeptide of cyclophilin B that comprises a tumor antigen peptide portion capable of binding to an HLA antigen and being recognized by cytotoxic T lymphocytes, or a gene encoding the cyclophilin B or the partial polypeptide thereof;

(15) an antibody that specifically binds to the tumor antigen peptide or the derivative thereof according to any one of the above (1) (11);

(16) an antigen-presenting cell wherein a complex between an HLA antigen and the tumor antigen peptide or the derivative thereof according to any one of the above (1) (11) is presented on the surface of a cell having antigen-presenting ability that is isolated from a tumor patient;

(17) an antigen-presenting cell on which a complex between an HLA antigen and a tumor antigen peptide derived from a cyclophilin is presented, said antigen-presenting cell being prepared by allowing a cell having antigen-presenting ability isolated from a tumor patient to be incorporated with the cyclophilin, a partial polypeptide thereof that comprises the tumor antigen peptide portion capable of binding to the HLA antigen and being recognized by cytotoxic T lymphocytes, or a gene encoding the cyclophilin or the partial polypeptide thereof;

(18) an antigen-presenting cell on which a complex between an HLA antigen and a tumor antigen peptide derived from cyclophilin B is presented, said antigen-presenting cell being prepared by allowing a cell having antigen-presenting ability isolated from a tumor patient to be incorporated with cyclophilin B, a partial polypeptide of cyclophilin B that comprises the tumor antigen peptide portion capable of binding to the HLA antigen and being recognized by cytotoxic T lymphocytes, or a gene encoding the cyclophilin B or the partial polypeptide thereof;

(19) a pharmaceutical composition for treating tumors, that comprises as an active ingredient the antigen-presenting cell according to any one of the above (16) (18);

(20) a cytotoxic T lymphocyte that specifically recognizes a complex between an HLA antigen and a tumor antigen peptide or derivative thereof according to any one of the above (1) (11);

(21) a cytotoxic T lymphocyte that specifically recognizes a complex between an HLA antigen and a tumor antigen peptide or derivative thereof, that is presented on an antigen-presenting cell according to any one of the above (16) (18);

(22) a pharmaceutical composition for treating tumors, that comprises as an active ingredient the cytotoxic T lymphocyte according to the above (20) or (21);

(23) a cytotoxic T lymphocyte of which deposit number is FERM BP-6725;

(24) a method for identifying tumor antigen proteins or tumor antigen peptides, which comprises using KG-CTL according to the above (23); and

(25) a diagnostic agent for tumors that comprises as an active ingredient a tumor antigen peptide or a derivative thereof according to any one of the above (1) (11).

The present invention is based on our first demonstration that substances called cyclophilins have an activity as a tumor antigen protein. Although the present invention is described below in detail with reference to cyclophilin B as an embodiment of the present invention, the following descriptions are not restricted to cyclophilin B and, also relate to the other known cyclophilins, that is, cyclophilins A, C, and D (Biochemistry, 3, 8218, 1994).

In the present invention, the term "tumor antigen peptide" refers to a partial peptide that comprises a part of cyclophilin B and is capable of binding to an HLA antigen and being recognized by CTL. Accordingly, any peptide falls within the scope of tumor antigen peptide of the present invention, regardless of its length or its position in the amino acid sequence of cyclophilin B, as long as the peptide comprises a part of the amino acid sequence of human cyclophilin B, which is registered in WWW Entrez databases as a GenBank Accession No. M60857 and is described in Proc. Natl. Acad. Sci. U.S.A., 88:1903 1907, 1991, and a complex between said peptide and an HLA antigen is capable of being recognized by CTL. Such tumor antigen peptides of the present invention can be identified by synthesizing a candidate peptide which comprises a part of cyclophilin B and conducting an assay for determining whether or not a complex between the candidate peptide and an HLA antigen is recognized by CTL, in other words, whether or not the candidate peptide has an activity as a tumor antigen peptide.

In this connection, synthesis of peptides may be conducted according to a method usually used in peptide chemistry. Examples of such known methods are those described in the literatures including "Peptide Synthesis", Interscience, New York, 1966; "The Proteins", vol. 2, Academic Press Inc., New York, 1976; "Pepuchido-Gosei", Maruzen Co. Ltd., 1975; "Pepuchido-Gosei-no-Kiso-to-Jikkenn", Maruzen Co. Ltd., 1985; and "Iyakuhin-no-Kaihatu, Zoku, vol. 14, Peputido-Gosei", Hirokawa Shoten, 1991.

Methods for identifying tumor antigen peptides of the present invention are further described below.

The respective sequence rules (motifs) of antigen peptides that are bound to and presented on the following HLA types have been known; HLA-A 1, -A0201, -A0204, -A0205, -A0206, -A0207, -A11, -A24, -A31, -A6801, -B7, -B8, -B2705, -B37, -Cw0401, and -Cw0602 (see, e.g., Immunogenetics, 41:178, 1995). Regarding the motif for HLA-A24, for example, it is known that in the sequence of peptides consisting of 8 to 11 amino acids, the amino acid at position 2 is tyrosine, phenylalanine, methionine, or tryptophan, and the amino acid at the C-terminus is phenylalanine, leucine, isoleucine, tryptophan, or methionine (J. Immunol., 152:3913, 1994; Immunogenetics, 41:178, 1995; J. Immunol., 155:4307, 1994). Likewise, the motifs shown in the following Table 1 are known for HLA-A2 (Immunogenetics, 41:178, 1995; J. Immunol., 155:4749, 1995).

TABLE-US-00001 TABLE 1 Amino acid at the second position Amino acid at Type of HLA-A2 from N-terminus C-terminus HLA-A0201 L, M V, L HLA-A0204 L L HLA-A0205 V, L, I, M L HLA-A0206 V, Q V, L HLA-A0207 L L (the peptides are 8 11 amino acids in length)

By analysis of antigen peptides bound to various HLA molecules (Immunogenetics, 41:178, 1995), it has been shown that the length of the peptides is usually about 8 to 14 amino acids long, although antigen peptides of 14 or more amino acids in length are also observed for HLA-DR, -DP, and -DQ.

It is easy to select peptide portions involved in such motifs from the amino acid sequence of cyclophilin B. That is, such peptide portions involved in the above motif structures can be easily selected by inspecting the amino acid sequence of cyclophilin B. Tumor antigen peptides of the present invention can be then identified by synthesizing candidate peptides thus selected, according to a method described above and conducting an assay for determining whether or not a complex between the candidate peptide and an HLA antigen is recognized by CTL, in other words, whether or not the candidate peptide has an activity as a tumor antigen peptide.

A specific example of the method for identifying tumor antigen peptides of the present invention is a method described in J. Immunol., 154:2257, 1995. Specifically, peripheral blood lymphocytes are isolated from a human who is positive for the type of an HLA antigen that is expected to present the candidate peptide, and are stimulated in vitro by adding the candidate peptide. If the candidate induces CTL that specifically recognizes the HLA-antigen-presenting cells pulsed with the candidate peptide, it is indicated that the candidate peptide may function as a tumor antigen peptide. In this connection, the presence or absence of CTL induction can be detected, for example, by measuring the amount of various cytokines (for example, IFN-.gamma.) produced by CTL in response to the antigen peptide-presenting cells using, for example, an ELISA method. Alternatively, a method in which the cytotoxicity of CTL against antigen peptide-presenting cells labeled with .sup.51Cr is measured (.sup.51Cr release assay, Int. J. Cancer, 58:317, 1994) may also be used for such detection.

Furthermore, the above detection can also be achieved as follows. An expression plasmid expressing a cDNA for the type of an HLA antigen that is expected to present the candidate peptide is introduced into, for example, COS-7 cells (ATCC No. CRL1651) or VA-13 cells (RIKEN CELL BANK, The Institute of Physical and Chemical Research), and the resultant cells are pulsed with the candidate peptide. The cells are then treated with the CTLs as describe above, and the amount of various cytokines (for example, IFN-.gamma.) produced by said CTLs is measured (J. Exp. Med., 187:277, 1998).

Specific examples of various assays as described above are illustrated below in Examples 7, 10, and 12 hereinafter.

Cyclophilin B contains HLA-A24- or HLA-A2-restricted tumor antigen peptide portions. In order to identify HLA-A24-restricted tumor antigen peptides, HLA-A24 cDNA (Cancer Res., 55:4248 4252, GenBank Accession No. M64740) can be used as a cDNA encoding the HLA antigen, along with those CTLs that are prepared by peptide-stimulation of human peripheral blood lymphocytes or KG-CTL (FERM BP-6725). Likewise, for HLA-A2-restricted tumor antigen peptides, identification of such tumor antigen peptides can be achieved in a similar manner to that described above except that HLA-A2 cDNA (GenBank Accession No. M84379) is used.

Apart from the above cases wherein the sequence rules (motifs) have been elucidated, in cases wherein a relevant peptide motif is not elucidated like HLA-A26, tumor antigen peptides of the present invention can be identified, for example, according to the method described in WO 97/46676, provided that a CTL line recognizing a complex between HLA-A26 and a tumor antigen peptide is available.

The methods for identifying tumor antigen peptides as described above may be hereinafter collectively referred to as "assay methods for tumor antigen peptides".

As described above, it is known that the sequences of tumor antigen peptides that are bound to and presented on HLA-A24 obey a certain rule (motif), and in particular, the motif is that, in a sequence of a peptide consisting of 8 to 11 amino acids, the amino acid at position 2 is tyrosine, phenylalanine, methionine, or tryptophan, and the amino acid at the C-terminus is phenylalanine, leucine, isoleucine, tryptophan, or methionine (J. Immunol., 152:3913, 1994; Immunogenetics, 41:178, 1995; J. Immunol., 155:4307, 1994). Likewise, a similar rule (motif can be found in the sequences of tumor antigen peptides that are bound to and presented on HLA-A2, and in particular, the motifs shown in the above Table 1 are known (Immunogenetics, 41, 178, 1995; J. Immunol., 155:4749, 1995). Accordingly, among tumor antigen peptides of the present invention, HLA-A24- and HLA-A2-restricted tumor antigen peptides are exemplified by those tumor antigen peptides that are partial peptides involved in such motif structures in the amino acid sequence of cyclophilin B and that are capable of binding to respective HLA antigens and being recognized by CTLs.

Particular examples of HLA-A24-restricted tumor antigen peptides described above are those tumor antigen peptides that comprises all or part of an amino acid sequence shown in any one of SEQ ID NOs: 1 11 and that are capable of binding to an HLA-A24 antigen and being recognized by CTL. Likewise, particular examples of HLA-A2-restricted tumor antigen peptides are those tumor antigen peptides that comprises all or part of an amino acid sequence shown in any one of SEQ ID NOs: 12 36 and that are capable of binding to an HLA-A2 antigen and being recognized by CTL.

Thus, examples of tumor antigen peptides of the present invention include:

1) peptides that consists of an amino acid sequence shown in any one of SEQ ID NOs: 1 36,

2) peptides that comprise the full length of an amino acid sequence shown in any one of SEQ ID NOs: 1 36 and that are elongated in the N-terminal and/or C-terminal direction as compared to said amino acid sequence, or peptides that consists of a consecutive portion of an amino acid sequence shown in any one of SEQ ID NOs: 1 36, said peptides being capable of binding to respective HLA antigens and being recognized by CTLs. In this context, the peptides in the above 2) may be about 8 11 amino acids in length in view of the fact that they are bound and presented by respective HLA antigens.

Suitable examples of HLA-A24-restricted tumor antigen peptides of the present invention include those tumor antigen peptides that comprise all or part of the amino acid sequence shown in SEQ ID NO: 1 or 2 and that are capable of binding to an HLA-A24 antigen and being recognized by CTL. Thus, examples are:

1) peptides that consists of the amino acid sequence shown in SEQ ID NO: 1 or 2,

2) peptides that comprise the full length of the amino acid sequence shown in SEQ ID NO: 1 or 2 and that are elongated in the N-terminal and/or C-terminal direction as compared to said amino acid sequence, or peptides that consists of a consecutive portion of the amino acid sequence shown in SEQ ID NO: 1 or 2, said peptides being capable of binding to HLA-A24 antigens and being recognized by CTLs. In this context, the peptides in the above 2) may be about 8 11 amino acids in length in view of the fact that they are bound to and presented on HLA-A24 antigens.

In the present invention, the term "derivative having properties functionally equivalent to those of a tumor antigen peptide" (hereinafter may be simply referred to as tumor antigen peptide derivative) refers to an altered peptide of which the amino acid sequence contains alteration of one or more, preferably one to several, amino acid residues of an amino acid sequence of a tumor antigen peptide of the present invention, and which has the properties as a tumor antigen peptide, that are to be capable of binding to an HLA antigen and being recognized by CTL. Accordingly, all altered peptides fall within the scope of tumor antigen peptide of the present invention so long as they contains alteration of one or more amino acid residues of an amino acid sequence of a tumor antigen peptide of the present invention, and have the properties as tumor antigen peptides, that is, are capable of binding to HLA antigens and being recognized by CTLs.

In this context, "alteration" of an amino acid residue means substitution, deletion and/or addition (including addition of amino acids to the N-terminus and/or the C-terminus of the peptide) of an amino acid residue, with substitution of an amino acid residue being preferred. For alterations involving substitution of an amino acid residue, although the number and the position of amino acid residues to be substituted may be determined arbitrarily so long as the activity as a tumor antigen peptide is retained, it is preferred that one to several residues are substituted since tumor antigen peptides are usually about 8 to 14 amino acids in length as described above.

A preferred length of tumor antigen peptide derivatives of the present invention is about 8 to 14 amino acids as in case of the tumor antigen peptide described above, although derivatives of 14 or more amino acids long may also be possible for HLA-DR, -DP, and -DQ.

Such tumor antigen peptide derivatives of the present invention can be identified by synthesizing altered peptides that contain alteration of a part of a tumor antigen peptide of the present invention in accordance with the above preparation of peptide, and by conducting the above assay for tumor antigen peptides.

As described above, the sequence rules (motifs) for peptides that are bound to and presented on HLA types such as HLA-A1, -A0201, -A0204, -A0205, -A0206, -A0207, -A11, -A24, -A31, -A6801, -B7, -B8, -B2705, -B37, -Cw0401, and -Cw0602 have been elucidated. Consequently, tumor antigen peptide derivatives containing alteration of one or more amino acids in a tumor antigen peptide of the present invention can be prepared on the basis of such motifs.

For example, regarding the motif for antigen peptides that are bound to and presented on HLA-A24, it is known as described above that in the sequence of a peptide consisting of 8 to 11 amino acids, the amino acid at position 2 is tyrosine, phenylalanine, methionine, or tryptophan, and the amino acid at the C-terminus is phenylalanine, leucine, isoleucine, tryptophan, or methionine (J. Immunol., 152:3913, 1994; Immunogenetics, 41:178, 1995; J. Immunol., 155:4307, 1994). Likewise, the motifs shown in the above Table 1 are known for HLA-A2. In addition, amino acid residues having properties similar to those of amino acids according to the motifs may also be accepted. Therefore, examples of tumor antigen peptide derivatives of the present invention include those peptide derivatives that comprise all or part of an amino acid sequence in which one or more amino acid residues at any positions that may be allowed for substitution according to the motifs (for HLA-A24 and HLA-A2, position 2 and the C-terminus) are substituted by other amino acids, and which derivatives have activity of binding to HLA antigens and being recognized by CTLs. Preferred examples are those tumor antigen peptide derivatives that comprise all or part of an amino acid sequence in which substitution of amino acid residues are selected from that of amino acid residues at said positions according to the above motifs, and which derivatives have the above activity. A preferred length of "all or part" of an amino acid sequence is about 8 to 14 amino acids, although it might be a length of 14 or more amino acids for HLA-DR, -DP, and -DQ.

Examples of HLA-A24- or HLA-A2-restricted tumor antigen peptide derivatives include those peptide derivatives that comprise all or part of an amino acid sequence in which one or more amino acid residues at positions that are allowed for substitution according to the above motifs, specifically, at positoin 2 and/or the C-terminus, of a peptide derived from the amino acid sequence of cyclophilin B having a binding motif for HLA-A24 or HLA-A2 are substituted by other amino acid residues, and which derivatives have the above activity. Preferred examples are those tumor antigen peptide derivatives that comprise all or part of an amino acid sequence in which the amino acid residues at position 2 and/or the C-terminus are substituted by amino acid residues according to the above motifs, and which derivatives have the above activity. In such HLA-A24- or HLA-A2-restricteid tumor antigen peptide derivatives, a preferred length of "all or part" of the amino acid sequence is about 8 to 11 amino acids.

In particular, examples are those tumor antigen peptide derivatives that comprise all or part of an amino acid sequence in which the amino acid residues at position 2 and/or the C-terminus of an amino acid sequence shown in any one of SEQ ID NOs: 1 to 36 are substituted by other amino acid residues and which derivatives have the above activity. Preferred examples are those tumor antigen peptide derivatives that comprise all or part of an amino acid sequence in which the amino acid residues at position 2 and/or the C-terminus of an amino acid sequence shown in any one of SEQ ID NOs: 1 to 36 are substituted by amino acid residues according to the above motifs and which derivatives have the above activity. Specifically, examples of HLA-A24-restricted tumor antigen derivatives are those tumor antigen peptide derivatives that comprise all or part of an amino acid sequence in which the amino acid residue at position 2 of an amino acid sequence shown in any one of SEQ ID NOs: 1 to 11 is substituted by tyrosine, phenylalanine, methionine, or tryptophan and/or the amino acid residue at the C-terminus is substituted by phenylalanine, leucine, isoleucine, tryptophan, or methionine and which derivatives have the above activity. Likewise, examples of HLA-A2-restricted tumor antigen derivatives are those tumor antigen peptide derivatives that comprise all or part of an amino acid sequence in which the amino acid residue at position 2 of an amino acid sequence shown in any one of SEQ ID NOs: 12 to 36 is substituted by leucine, methionine, valine, isoleucine, or glutamine and/or the amino acid residue at the C-terminus is substituted by valine or leucine and which derivatives have the above activity.

Suitable examples of HLA-A24-restricted tumor antigen peptide derivatives of the present invention are those tumor antigen peptide derivatives that comprise all or part of an amino acid sequence in which the amino acid residues at position 2 and/or the C-terminus of the amino acid sequence shown in SEQ ID NO: 1 or 2 are substituted by other amino acid residues and which derivatives have the above activity. More preferred examples are those tumor antigen peptide derivatives that comprise all or part of an amino acid sequence in which one or more amino acid residues are substituted according to the above motifs, that is, all or part of the amino acid sequence shown in SEQ ID NO: 37 or 38 and which derivatives have the above activity. Suitable examples of such tumor antigen peptide derivatives are shown in SEQ ID NOs: 39 and 40.

Furthermore, as described above, besides cyclophilin B described above, homologs of cyclophilin B, cyclophilins A, C, and D, are also tumor antigen proteins generating tumor antigen peptides. Specific examples of such tumor antigen peptides include HLA-A24-restricted tumor antigen peptides such as SEQ ID NO: 41 (cyclophilin A), SEQ ID NO: 42 (cyclophilin C), and SEQ ID NO: 43 (cyclophilin D).

A tumor antigen peptide or its derivative of the present invention can be used for a pharmaceutical composition for treating or preventing tumors as follows.

When used with the aim of treating or preventing tumors, at least one of, or a combination of two or more of, tumor antigen peptides or their derivatives of the present invention is administered to a patient, if necessary, in combination with other agents such as other tumor antigen peptides. When the composition for treating or preventing tumors which comprises as an active ingredient a tumor antigen peptide or its derivative of the present invention is administered to a cyclophilin B-positive patient, the tumor antigen peptide or derivative thereof is presented at a high density with an HLA antigen of antigen-presenting cells, and therefore, CTLs specific for the presented HLA antigen complex proliferates and destroys the tumor cells. As a result, the tumor of the patient may be treated, or proliferation or metastasis of the tumor may be prevented. Furthermore, the composition for treating or preventing tumors comprising as an active ingredient a tumor antigen peptide or its derivative of the present invention can achieve an increased therapeutic effect by its combined use with a chemotherapy or radiotherapy.

The composition for treating or preventing tumors comprising as an active ingredient a tumor antigen peptide or its derivative of the present invention may be administered along with an adjuvant in order to effectively establish the cellular immunity, or may be 110 administered in a particulate dosage form. For such purpose, those adjuvants described in the literature (Clin. Microbiol. Rev., 7:277 289, 1994) are applicable. In addition, liposomal preparations, particulate preparations in which the ingredient is bound to beads having a diameter of several .mu.m, or preparations in which the ingredient is attached to lipids are also possible. Administration may be achieved, for example, intradermally, hypodermically, or by intravenous injection. Although the amount of a tumor antigen peptide or its derivative of the present invention in the formulation to be administered may be adjusted as appropriate depending on, for example, the disease to be treated, the age and the body weight of the particular patient, it is usually preferred to administered 0.0001 mg to 1000 mg, preferably 0.001 mg to 1000 mg, and more preferably 0.1 mg to 10 mg every several days to every several months.

Furthermore, cyclophilin B protein from which tumor antigen peptides of the present invention are derived or a gene encoding said cyclophilin B may also be used for a pharmaceutical composition for treating or preventing tumors.

In addition to the full-length cyclophilin B or the full-length gene therefor, any parts thereof, such parts linked together, or even those containing alterations in their base or amino acid sequences can achieve desired treatment or prevention of tumors so long as they comprise at least one of peptide portions that can bind to an HLA antigen and being recognized by CTLs. In this context, those substances that "comprise at least one of peptide portions that can bind to an HLA antigen and being recognized by CTLs" are herein referred to as "partial polypeptides".

When cyclophilin B protein or its partial polypeptide is applied as the composition for treating or preventing tumors, it may be administered in a dosage form, administration mode, and dose similar to the above tumor antigen peptide or derivative thereof. When administered to a tumor patient, cyclophilin B protein or its partial polypeptide is incorporated into antigen-presenting cells, and tumor antigen peptides that are subsequently generated by intracellular degradation bind to HLA antigens to form complexes. The complexes are presented at a high density on the surface of antigen-presenting cells, and CTLs specific for the presented complex efficiently proliferate in the body and destroy the tumor cells. In this manner, treatment or prevention of tumors is achieved.

In order to apply a gene encoding cyclophilin B or its partial polypeptide to a composition for treating or preventing tumors, the following methods may be used.

Administration and introduction of the gene of the present invention into cells may be achieved using viral vectors or according to any one of other procedures (Nikkei-Science, April, 1994, pp. 20 45; Gekkan-Yakuji, 36(1), 23 48 (1994); Jikken-Igaku-Zokan, 12(5), 1994, and references cited therein).

Examples of the methods using viral vectors include those methods in which DNA of the present invention is incorporated into DNA or RNA virus such as retrovirus, adenovirus, adeno-associated virus, herpesvirus, vaccinia virus, poxvirus, poliovirus, or Sindbis virus, and introduced into cells. Among these methods, those using retrovirus, adenovirus, adeno-associated virus, or vaccinia virus are particularly preferred.

Other methods may include those in which expression plasmids are directly injected intramuscularly (DNA vaccination), the liposome method, Lipofectin method, microinjection, the calcium phosphate method, and electroporation, with DNA vaccination and the liposome method being particularly preferred.

In order to allow a gene of the present invention to act as a medicine in practice, one can use either of two methods: an in vivo method in which DNA is directly introduced into the body, or an ex vivo method in which certain cells are removed from human, and after introducing DNA into said cells extracorporeally, the cells are reintroduced into the body (Nikkei-Science, April, 1994, pp. 20 45; Gekkan-Yakuji, 36(1), 23 48 (1994); Jikkenn-Igaku-Zokan, 12(15), 1994; and references cited therein). An in vivo method is more preferred.

In the case of in vivo methods, the gene may be administered by any appropriate route depending on the disease and symptoms to be treated and other factors. For example, it may be administered via intravenous, intraarterial, subcutaneous, intracutaneous, or intramuscular route. In the case of in vivo methods, the compositions may be administered in various dosage forms such as solution, and are typically formulated, for example, in the form of injection containing DNA of the present invention as an active ingredient, to which conventional carriers may also be added, if necessary. If a gene of the present invention is included in liposomes or membrane-fused liposomes (such as Sendai virus (HVJ)-liposomes), the compositions may be in the form of liposome formulations such as suspension, frozen drug, centrifugally-concentrated frozen drug or the like.

Although the amount of a gene of the present invention in such formulations may vary depending on the disease to be treated, the age and weight of the patient, and the like, it is typically preferred to administer 0.0001 100 mg, preferably 0.001 10 mg, of a gene of the present invention every several days to every several months.

By such administration of a gene of the present invention, the tumor antigen protein is highly expressed in antigen-presenting cells. Tumor antigen peptides that are subsequently generated by intracellular degradation bind to HLA antigens to form complexes, and the complexes are densely presented on the cell surface. As a result, CTLs specific for these complexes efficiently proliferate in the body, and destroy tumor cells. In this way, treatment or prevention of proliferation or metastasis of tumors are achieved.

Cyclophilin B, partial polypeptides thereof, and genes encoding such substances that can be used as medicaments as described above may be prepared as follows. A gene encoding cyclophilin B can be easily cloned by preparing appropriate PCR primers on the basis of the base sequence of human cyclophilin B cDNA registered at GenBank under Accession No. M60857 as found by WWW Entrez databases search, and using them to conduct PCR according to the description of a standard text such as "Molecular Cloning", 2nd ed., Cold Spring Harbor Laboratory Press (1989). For this purpose, one may also consult Proc. Natl. Acad. Sci. U.S.A. 88:1903, 1991, which is a report concerning cloning of cyclophilin B. Furthermore, a commercially available cyclophilin B cDNA clone (ATCC No. 107758, Designations: HTNAQ10) may be also used. If desired, alteration may be easily made according to a standard text such as the aforementioned "Molecular Cloning". Furthermore, expression of cyclophilin B protein using a gene encoding human cyclophilin B thus cloned may be achieved according to many publications and references such as "Molecular Cloning" mentioned above. An expression plasmid which replicates and functions in host cells is constructed by incorporating DNA to be expressed into an appropriate vector (e.g., pSV-SPORT1), in some cases after adding regulatory sequence(s) such as a promoter sequence, which controls transcription (e.g., trp, lac, T7, or SV40 early promoter), upstream to the DNA. The expression plasmid is then introduced into appropriate host cells to obtain transformants. Examples of host cells include, for example, prokaryotes such as Escherichia coli, unicellular eukaryotes such as yeast, and cells derived from multicellular eukaryotes such as insects or animals. Gene transfer into host cells may be achieved by the calcium phosphate method, DEAE-dextran method, the electric pulse method, or the like. Transformants cultured in appropriate medium produce the protein of interest. The tumor antigen protein thus obtained may be isolated and purified according to standard biochemical procedures.

It can be determined whether or not cyclophilin B protein, a partial polypeptide thereof, or a gene encoding such substance prepared as described above has activity as a tumor antigen, that is, whether or not tumor antigen peptides capable of binding to an HLA antigen and being recognized by CTL are generated by intracellular degradation of said protein, for example, by a method using gene expression as follows.

First of all, an expression plasmid containing a candidate gene or gene fragment and another expression plasmid containing DNA encoding an HLA antigen are doubly transfected into cells expressing no tumor antigen proteins, such as COS-7 (ATCC CRL 1651) derived from African green monkey kidney, or fibroblast VA-13 (RIKEN CELL BANK, The Institute of Physical and Chemical Research). The transfection may be achieved, for example, by Lipofectin method using Lipofectamine reagent (Gibco BRL). Subsequently, a tumor-responsive CTL that is restricted to the particular HLA antigen used is added, allowed to act on the transfectants, and then the amount of various cytokines (for example, IFN-.gamma.) produced by said CTL in response to the target cells may be measured, for example, by ELISA to determine whether the candidate gene is a DNA encoding a tumor antigen protein. Since cyclophilin B contains HLA-A24- or HLA-A2-restricted tumor antigen peptide portions, for example, HLA-A24 cDNA (Cancer Res., 55:4248 4252 (1995); GenBank Accession No. M64740) or HLA-A2 cDNA (GenBank Accession No. M84379) may be used as the above DNA encoding the HLA antigen, and those CTLs that are prepared from human peripheral blood lymphocytes as well as KG-CTL (FERM BP-6725) may be used as the above CTL.

A specific example of such activity measurement is described below in Example 2.

Antibodies that specifically bind to a tumor antigen peptide of the present invention or a derivative thereof are also included in the present invention. Such antibodies are easily prepared, for example, according to a method described in "Antibodies: A Laboratory Manual", Lane, H. D. et al. eds., Cold Spring Harbor Laboratory Press, New York, 1989. Specifically, antibodies that recognize a tumor antigen peptide or its derivative of the present invention and antibodies that further neutralize its activity may easily be prepared using the tumor antigen peptide or derivative thereof to appropriately immunize an animal in the usual manner. Such antibodies may be used in affinity chromatography, immunological diagnosis, and the like.

Immunological diagnosis for the presence or absence of tumors using said antibody may be conducted by firstly labeling the above antibody as needed, and using it to detect the presence of antigens in a sample (such as blood, tumor tissue) obtained from a patient suspected to have a tumor. In particular, such immunological diagnosis may be selected as appropriate from immunoblotting, radioimmunoassay (RIA), enzyme-linked immunosorbent assay (ELISA), a fluorescent or luminescent assay, and the like.

A tumor antigen peptide, derivative thereof, tumor antigen protein (cyclophilin B), or gene therefor of the present invention may also be used in vitro for treatment of tumor patients as follows.

On usage of a tumor antigen peptide, derivative thereof, tumor antigen protein, or gene therefor in treatment of tumor, it is important to establish an administration method which can efficiently induce specific CTLs in the body of a patient. As one of the means therefor, the present invention provides an antigen-presenting cell which comprises a complex between an HLA antigen and a tumor antigen peptide or its derivative of the present invention, the complex being presented on the surface of a cell having antigen-presenting ability isolated from a tumor patient, and also provides a pharmaceutical composition for treating tumors, that comprises said antigen-presenting cell as an active ingredient.

In this context, the "cell having antigen-presenting ability" is not specifically restricted so long as it is a cell expressing on its cell surface an HLA antigen capable of presenting a tumor antigen peptide or its derivative of the present invention, and dendritic cells, which is reported to have especially high antigen-presenting ability, are preferred. The substance to be added to prepare an antigen-presenting cell of the present invention from the above-mentioned cell having antigen-presenting ability may be tumor antigen peptides or their derivatives of the present invention, as well as the tumor antigen protein, cyclophilin B, and a gene therefor. In order to prepare an antigen-presenting cell of the present invention, not only the full-length cyclophilin B and gene therefor but also its partial polypeptide and a gene therefor may also be used. When used in the form of a protein or gene, it is necessary to be incorporated into cells. In this regard, see the above descriptions for the composition for treating or preventing tumors comprising the gene or protein as an active ingredient.

In order to prepare antigen-presenting cells of the present invention, cells having antigen-presenting ability are isolated from a tumor patient, and pulsed ex vivo with a tumor antigen peptide, a derivative thereof, a tumor antigen protein, or its partial polypeptide of the present invention to form a complex between an HLA antigen and said tumor antigen peptide or derivative thereof (Cancer Immunol. Immunother., 46:82, 1998; J. Immunol. 158:1796, 1997; Cancer Res., 59:1184, 1999). When dendritic cells are used, antigen-presenting cells of the present invention may be prepared, for example, by isolating lymphocytes from peripheral blood of a tumor patient using Ficoll method, removing non-adherent cells, incubating adherent cells in the presence of GM-CSF and IL-4 to induce dendritic cells, and incubating and pulsing said dendritic cells with a tumor antigen peptide, tumor antigen protein of the present invention, or the like. For details, see Example 13.

When antigen-presenting cells of the present invention are prepared by introducing a gene encoding a tumor antigen protein or its partial polypeptide of the present invention into the aforementioned cells having antigen-presenting ability, said gene may be in the form of DNA or RNA. In particular, DNA may be used consulting, for example, Cancer Res., 56:5672, 1996 or J. Immunol., 161:5607, 1998, and RNA may be used by consulting, for example, J. Exp. Med., 184:465, 1996.

A pharmaceutical composition for treating tumors which comprises the above antigen-presenting cells as an active ingredient preferably contains physiological saline, phosphate buffered saline (PBS), medium, or the like in order to stably maintain the antigen-presenting cells. It may be administered, for example, intravenously, subcutaneously, or intradermally. By reintroducing such composition for treating tumors which comprises antigen-presenting cells as an active ingredient into the body of the patient, specific CTLs are efficiently induced in the cyclophilin B-positive patient to achieve treatment of the tumor. It should be undisputed that the HLA types need be compatible between the patient and the peptide used. For example, an HLA-A24-restricted tumor antigen peptide or a derivative thereof must be used with an HLA-A24-positive tumor patient.

In addition, another example of in vitro use of a tumor antigen peptide, a derivative thereof, a tumor antigen protein, or a gene therefor according to the present invention is in the following adoptive immunotherapy.

For melanomas, it has been observed that an adoptive immunotherapy wherein tumor infiltrating T cells taken from the patient himself/herself are cultured ex vivo in large quantities, and then returned into the patient, achieves an therapeutic effect (J. Natl. Cancer. Inst., 86:1159, 1994). Likewise, in mouse melanoma, suppression of metastasis has been observed by in vitro stimulation of splenocytes with a tumor antigen peptide TRP-2, thereby proliferating CTLs specific for the tumor antigen peptide, and administering said CTLs into a melanoma-grafted mouse (J. Exp. Med., 185:453, 1997). This resulted from in vitro proliferation of CTL that specifically recognizes the complex between an HLA antigen of antigen-presenting cells and the tumor antigen peptide. Accordingly, a method for treating tumors is believed to be useful, which comprises in vitro stimulation of peripheral blood lymphocytes from a patient using a tumor antigen peptide, a derivative thereof, a tumor antigen protein, or a gene therefor according to the present invention to proliferate tumor-specific CTLs and subsequent return of the CTLs into the patient.

Thus, the present invention provides CTLs that specifically recognize a complex between the HLA antigen and the tumor antigen peptide or derivative thereof, and also provides a pharmaceutical composition for treating tumors which comprises said CTLs as an active ingredient. Such composition preferably contains physiological saline, phosphate buffered saline (PBS), medium, or the like in order to stably maintain CTLs. It may be administered, for example, intravenously, subcutaneously, or intradermally. By reintroducing the composition for treating tumors which comprises CTLs as an active ingredient into the body of the patient, the toxic effect of CTLs against the tumor cells is enhanced in the cyclophilin B-positive patient and thereby destroys the tumor cells to achieve treatment of the tumor.

Tumor antigen proteins, tumor antigen peptides, and derivatives thereof according to the present invention may be also used as an active ingredient of a diagnostic agent for diagnosing tumors. Thus, by using a tumor antigen protein, tumor antigen peptide, or derivative thereof according to the present invention itself as a diagnostic agent to detect the presence of antibodies in a sample (such as blood or a tumor tissue) obtained from a patient suspected to have a tumor, early detection of tumors and diagnosis of recurrence and metastasis are possible. The same procedure can also be used for selection of tumor patients to whom medicines comprising as an active ingredient, for example, a tumor antigen protein or tumor antigen peptide of the present invention can be applied. In particular, such diagnosis may be conducted using immunoblotting, RIA,