Immune responses to weakly immunogenic virally induced tumors. I. Overcoming low responsiveness by priming mice with a syngeneic in vitro tumor line or allogeneic cross-reactive tumor.
This report describes model systems which show low primary in vitro syngeneic cytotoxic responses to a Moloney-induced YAC tumor (syngeneic in A mice) and a Rauscher-induced RBL5 tumor (syngeneic in C57BL/6 mice) and examines different approaches to overcome these defects. Two major findings were obtained: (a) spleen cells from A mice, injected with tumor cells from an in vitro tumor line YAC-1, derived from YACL, could generate a significant syngeneic cytotoxic response. In contrast, spleen cells from A mice injected with tumor cells from the in vivo tumor line failed to generate a syngeneic cytotoxic response. Thus, tumor cells from the in vitro line were more immunogeneic that those from the in vivo line. (b) Spleen cells from A mice which were injected with the cross-reactive allogeneic tumor RBL5, could generate significant cytotoxic responses to the syngeneic tumors YAC and YAC-1. Similarly, spleen cells from C57BL/6 mice injected with the cross-reactive allogeneic tumor YAC-1, could generate a significant cytotoxic response to the syngeneic tumor RBL5. Thus, cross-reactive allogeneic tumors could stimulate syngeneic cytotoxicity. The theoretical and the practical implications of these studies are discussed.
D000818:Animals; D000917:Antibody Formation; D002460:Cell Line; D003429:Cross Reactions; D003602:Cytotoxicity, Immunologic; D004306:Dose-Response Relationship, Immunologic; D005260:Female; D051379:Mice; D008805:Mice, Inbred A; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008979:Moloney murine leukemia virus / Q000276:immunology; D009374:Neoplasms, Experimental / Q000276:immunology*; D013154:Spleen / Q000276:immunology