title: T-T hybridoma product specifically suppresses tumor immunity.
abstract: Culture supernatants of spleen or thymus cells from BALB/c mice bearing transplanted, syngeneic, methylcholanthrene-induced sarcomas suppress T lymphocyte-mediated lysis of cells from the tumor borne by the donor of the spleen or thymus cells. On this basis, we hybridized thymus cells from mice bearing sarcoma MCA-1490 with cells from the T lymphoma BW5147. The hybrids (hybridomas) formed were tested for production of factors that could suppress T lymphocyte-mediated lysis of MCA-1490 cells. One hybridoma, and a clone derived from it, produced factors that suppressed the lysis of MCA-1490 cells in vitro. In addition, these factors enhanced the growth of MCA-1490 in immune mice and prevented the destruction of MCA-1490 cells by immune lymphocytes in tumor neutralization (Winn) assays. In vitro lysis of cells from another MCA-induced sarcoma by immune lymphocytes was not suppressed. The suppressor factors did not affect the proliferative response of BALB/c lymphocytes to mitogens or the generation of a cytotoxic response to C57BL/6 alloantigens. Neither did they inhibit the generation of primary or secondary cytotoxic responses to murine leukemia virus-related antigens present on a BALB/c lymphoma line, LSTRA. Although our findings suggest that these suppressor factors are specific for MCA-1490, their specificity for antigens restricted to this tumor needs further definition.
mesh_terms: D000818:Animals; D003602:Cytotoxicity, Immunologic; D006822:Hybrid Cells / Q000276:immunology*; D007111:Immunity, Cellular; D008213:Lymphocyte Activation; D051379:Mice; D009194:Myeloma Proteins / Q000276:immunology; D012513:Sarcoma, Experimental / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
chemical_list: D009194:Myeloma Proteins