Detection of a TL(+) murine leukemia cell line that resists the cytotoxic effects of guinea pig complement and specific antiserum.
RADA-1 cells [H-2a thy-1b; thymus-leukemia (TL) 1, 2, 3], a radiation-induced murine leukemia cell line maintained by serial transfer in histocompatible recipients, resisted lysis by guinea pig complement (GPC) and TL 1, 3; TL 2; or TL 1, 2, 3 antiserum. The cells expressed TL antigenic specificities as determined by indirect fluorescent antibody methods, the direct isolation of TL antigens from the cells, and the capacity of the cells to reduce known titers of TL antisera. GPC was consumed to the same extent during the reaction of resistant cells and TL antisera as occurred in the reaction of sensitive cells (killed under similar conditions) and TL antisera. RADA-1 cells were not nonspecifically resistant to complement (C)-mediated lysis; they were killed in the presence of H-2a antiserum and GPC. The TL antisera contained antibodies for TL determinants. They stimulated the C-mediated lysis of ASL-1 cells (TL 1, 2, 3) and thymocytes from strain A mice (TL 1, 2, 3). The TL antigens of resistant RADA-1 cells underwent antigenic modulation, the reversible disappearance of TL antigens from the cells stimulated by specific antiserum. After the cells were treated with neuraminidase, they became susceptible to the cytotoxic effects of aliquots of the same TL antisera and GPC used previously.
D000818:Animals; D000912:Antibodies, Neoplasm; D000951:Antigens, Neoplasm / Q000302:isolation & purification; D002460:Cell Line; D002462:Cell Membrane / Q000276:immunology; D003168:Complement Fixation Tests; D003165:Complement System Proteins; D003601:Cytotoxicity Tests, Immunologic; D000939:Epitopes; D006168:Guinea Pigs / Q000276:immunology; D006649:Histocompatibility Antigens; D007942:Leukemia, Experimental / Q000276:immunology*; D051379:Mice; D008815:Mice, Inbred Strains; D009439:Neuraminidase / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D013696:Temperature
D000912:Antibodies, Neoplasm; D000951:Antigens, Neoplasm; D000939:Epitopes; D006649:Histocompatibility Antigens; D003165:Complement System Proteins; D009439:Neuraminidase