Immune responses to weakly immunogenic virally induced tumors. II. Suppressive effects of the in vivo carried tumor YAC.
Unprimed spleen cells from A and C57BL/6 mice could not produce cytotoxic responses to their syngeneic tumors: a Moloney virus-induced in vitro subline YAC-1 and a Rauscher virus-induced in vitro subline RBL5, respectively. Spleen cells from A and C57BL/6 mice immunized with YAC-1 OR RBL5 (which cross-react serologically) generated significant syngeneic cytotoxicities after cultivation in vitro. The in vivo carried tumor of A mice, unlike the in vitro sublines, could not stimulate a priming effect. In contrast, YAC stimulated the formation of suppressor cells in both A and C57BL/6 mice. The suppressor cells abrogated the priming effect of the syngeneic tumors, but not the priming effect of the allogeneic tumors. Furthermore, YAC did not suppress normal allogeneic anti-tumor responses. The theoretical and the practical implications of these studies are discussed.
D000818:Animals; D000917:Antibody Formation; D003429:Cross Reactions; D007165:Immunosuppression Therapy; D007942:Leukemia, Experimental / Q000276:immunology*; D051379:Mice; D008805:Mice, Inbred A; D008810:Mice, Inbred C57BL; D008979:Moloney murine leukemia virus; D011925:Rauscher Virus; D014181:Transplantation Immunology