title: A mouse mutant p53 product recognized by CD4+ and CD8+ T cells.
abstract: The T-cell response to mutated and normal p53 products of BALB/c-derived Meth A sarcoma was analyzed. Meth A p53 is known to have three missense point mutations in codons 132, 168, and 234, and 24 peptides containing wild-type or mutated sequences at the three mutation sites were constructed. Spleen cells from BALB/c or (BALB/c x C57BL/6)F1 mice immunized with p53 peptides were sensitized in vitro with the corresponding peptides. Because Meth A is resistant to cytotoxic T cells, the sensitive P1-HTR cell line, which expresses a low level of p53 lacking the Meth A p53 mutations, was chosen as a target, either pulse-labeled with p53 peptides or transfected with plasmids containing coding sequences from Meth A p53. One peptide, a nonamer containing the codon 234 mutation (234CM), induced CD8+ cytotoxic T cells that lysed 234CM-pulsed P1-HTR cells in an H-2Kd-restricted fashion. P1-HTR cells pulsed with the corresponding wild-type peptide were only weakly lysed by 234CM-reactive cytotoxic T cells. P1-HTR cells pulsed with other wild-type or mutated p53 peptides were not lysed by 234CM-reactive cytotoxic T cells, nor could these peptides, including 234CW (the wild-type counterpart to 234CM), elicit cytotoxic cells. P1-HTR cells transfected with plasmids coding for the 234CM sequence and expressing high p53 levels were weakly lysed by 234CM-reactive cytotoxic T cells. However, lysis of one of the transfectants was significantly increased by pretreatment with interferon gamma. A proliferative response of CD4+ T cells was elicited by immunization with 234CM and 234CW, but not with other p53-related peptides. The specificity of 234CM-induced CD4+ T cells for 234-region peptides was broader than the reactivity of 234CM-reactive cytotoxic T cells. Mice immunized with 234CM in incomplete Freund's adjuvant showed heightened resistance to Meth A challenge.
authors.affiliation: Ludwig Institute for Cancer Research, New York Unit, Memorial Sloan-Kettering Cancer Center, NY 10021.
authors.forename: Y
authors.initials: Y
authors.lastname: Noguchi
authors.forename: Y T
authors.initials: YT
authors.lastname: Chen
authors.forename: L J
authors.initials: LJ
authors.lastname: Old
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D016827:CD8 Antigens / Q000032:analysis; D003602:Cytotoxicity, Immunologic; D005260:Female; D007111:Immunity, Cellular; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D010455:Peptides / Q000276:immunology; D012513:Sarcoma, Experimental / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D016159:Tumor Suppressor Protein p53 / Q000276:immunology*
chemical_list: D016827:CD8 Antigens; D010455:Peptides; D016159:Tumor Suppressor Protein p53