title: Induction of immune reaction against rat embryonal carcinoma by activation of viral genome.
abstract: A cell line (F3/1) derived from a rat embryonal carcinoma, originally induced in fetectomized rats injected with MSV, was found to be essentially non-immunogenic in a syngeneic host; the cells did not produce C-type virions. The MSV genome could be rescued by superinfection of F3/1 cells with endogenous C-type mouse virus and the cells were converted in a producer line-F3/1-P. The produced virus was shown to be MSV by its ability to induce focus formation in mouse fibroblasts. In contrast to its non-producer ancestor, the F3/1-P line proved to be strongly immunogenic in the syngeneic host. These results indicate the possibility of converting certain non-immunogenic tumors into immunogenic ones by the activation of dormant viral genome using xenogeneic non-oncogenic helper virus.
mesh_terms: D000818:Animals; D002460:Cell Line; D005814:Genes, Viral; D007114:Immunization; D008214:Lymphocytes / Q000276:immunology; D051379:Mice; D009374:Neoplasms, Experimental / Q000276:immunology; D051381:Rats; D012190:Retroviridae / Q000235:genetics; D009053:Sarcoma Viruses, Murine / Q000235:genetics; D013724:Teratoma / Q000276:immunology* / Q000382:microbiology; D014775:Virus Activation