MAGE-C2 antigenic peptides and uses thereof

#This invention relates to isolated peptides which bind to HLA, particularly HLA-A2, and uses thereof. The peptides are derived from members of the MAGE family of tumor rejection antigen precursors. This invention also relates to nucleic acid molecules encoding the peptides, complexes of the peptides and HLA molecule, and to cells expressing the HLA/peptide complexes on their surfaces, as well as uses of the nucleic acid molecules, the HLA/peptide complexes, and the cells expressing the complexes in the diagnosis and treatment of pathological conditions.

#The process by which the mammalian immune system recognizes and reacts to foreign or alien materials is a complex one. An important facet of the system is the T cell response. This response requires that T cells recognize and interact with complexes of cell surface molecules, referred to as human leukocyte antigens (“HLAs”), or major histocompatibility complexes (“MHCs”), and peptides. The peptides are derived from larger molecules which are processed by the cells which also present the HLA/MHC molecule. See in this regard Male et al., Advanced Immunology (J.P. Lipincott Company, 1987), especially chapters 6-10. The interaction of T cell and complexes of HLA/peptide is restricted, requiring a T cell specific for a particular combination of an HLA molecule and a peptide. If a specific T cell is not present, there is no T cell response even if its partner complex is present. Similarly, there is no response if the specific complex is absent, but the T cell is present. This mechanism is involved in the immune system's response to foreign materials, in autoimmune pathologies, and in responses to cellular abnormalities. Much early work focused on the mechanisms by which proteins are processed into the HLA binding peptides. See, in this regard, Barinaga, Science 257: 880 (1992); Fremont et al., Science 257: 919 (1992); Matsumura et al., Science 257: 927 (1992); Latron et al., Science 257: 964 (1992).

#The mechanism by which T cells recognize cellular abnormalities has also been implicated in cancer. For example, PCT application PCT/US92/04354, filed May 22, 1992, published on Nov. 26, 1992, and incorporated by reference, discloses a family of genes that are processed into peptides which, in turn, are expressed on cell surfaces and lead to lysis of the tumor cells by specific CTLs. The genes are said to code for “tumor rejection antigen precursors” or “TRAP” molecules, and the peptides derived therefrom are referred to as “tumor rejection antigens” or “TRAs”. See Traversari et al., Immunogenetics 35: 145 (1992); van der Bruggen et al., Science 254: 1643 (1991) and U.S. Pat. No. 5,342,774 and U.S. Pat. No. 5,462,871.

#FIG. 1 depicts the specific lysis of autologous melanoma cell line EB81-MEL.2 by CTL clone 606 C/22.2. The indicated target cells were labeled with chromium and incubated with CTL at different effector-to-target ratios. Chromium release was measured after 4 hours.

#FIG. 2 demonstrates the HLA restriction of CTL clone 606 C/22.2. Autologous melanoma cell line EB81-MEL.2 was used to stimulate CTL 606 C/22.2 in the absence or in the presence of monoclonal antibodies to different HLA molecules. After 18 hours of coculture, the production of TNF by CTL was measured by testing the toxicity of the supernatants to TNF-sensitive cell line WEHI-164.13.

#FIG. 3 depicts the recognition of different cell lines by CTL 606 C/22.2 LB37-NSCLC is a non-small-cell lung carcinoma cell line. LB129-SCLC is a small cell lung carcinoma cell line. LB39-MEL, SK23-MEL, AVL3-MEL, LB373-MEL are melanoma cell lines. U266 is a myeloma cell line. All of the cell lines aforementioned are HLA-A2 positive. MZ2-MEL.43/A2 is a melanoma cell line transfected with HLA-A2. LB831-BLC is a bladder carcinoma cell line, which was HLA-A2 negative, and was transiently transfected with HLA-A2 before adding CTL. Tumor cells and CTL were incubated over 18 hours, and the production of TNF by the CTL was measured by testing the toxicity of the supernatants to the TNF-sensitive WEHI-164.13 cells.

#Disclosed herein is the identification of peptides derived from MAGE-C2 that bind to HLA molecules, particularly HLA-A2 molecules. Also disclosed are nucleic acid molecules that encode the peptides, complexes of the peptides and HLA molecules and methods for using the peptides and complexes comprising the peptides in diagnostic and therapeutic assays.

#This invention relates to isolated peptides consisting of the amino acid sequence ALKDVEERX (SEQ ID NO: 1) or LKDVEERV (SEQ ID NO: 2), particularly an isolated peptide consisting of the amino acid sequence ALKDVEERX wherein X may be any amino acid, preferably a hydrophobic amino acid, more preferably X is Ala, Val, Leu, Ile, Pro, Phe, Met, Trp or Glu and most preferably X is an valine (SEQ ID NO: 3) or alanine (SEQ ID NO: 5).

#This invention also relates to the isolated peptides recited in Table 2, infra.