title: Defective T helper activity in the spleen of BALB/c mice immune to a syngeneic fibrosarcoma.
abstract: BALB/c mice were immunized with the syngeneic 3-methylcholanthrene-induced fibrosarcoma CA-2 by the growth and excision method. When lymphoid cells from different organs of these tumor-free mice were tested in a direct 51Cr-release assay, peritoneal exudate cells but not spleen cells displayed specific cytotoxicity against the syngeneic tumor target. A cytotoxic response could be obtained by tumor-immune spleen cells when cultured in a mixed lymphocyte tumor cell culture (MLTC) at high but not low density although at the same effector/stimulator ratio. Lack of cytotoxic activity in low density MLTC was not due to an impairment of cytotoxic precursors since cytotoxicity was rescued by adding exogenous interleukin-2 in experimental conditions in which no lymphokine-activated killer cells could develop relevant anti-CA-2 lysis. When low density MLTC were supplemented with either 800 R-irradiated cells or nonirradiated, negatively selected Lyt 1+ cells from the same immune mice, induction of a cytotoxic response against CA-2 occurred and interleukin-2 production became detectable. Additional studies indicated that spleen cells of CA-2-immune mice were also impaired in their ability to provide help to syngeneic thymocytes for the generation of cytotoxic T lymphocytes against C57BL/6J alloantigens. Dilution effect of helper cells due to immunization procedures was excluded since spleen cells of mice immunized against another BALB/c tumor, the YC8 lymphoma, or against DBA/2 minor histocompatibility antigens provided good help to thymocytes against the same alloantigens. These results indicate that tumor-immune animals may also have selective T helper defects in an important lymphoid organ like spleen.
mesh_terms: D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000032:analysis; D001202:Ascitic Fluid / Q000276:immunology; D003602:Cytotoxicity, Immunologic; D006649:Histocompatibility Antigens / Q000276:immunology; D007108:Immune Tolerance; D007109:Immunity; D007111:Immunity, Cellular; D007376:Interleukin-2 / Q000276:immunology; D051379:Mice; D012513:Sarcoma, Experimental / Q000276:immunology*; D013154:Spleen / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D006649:Histocompatibility Antigens; D007376:Interleukin-2