Characterization of gP85gag as an antigen recognized by Moloney leukemia virus-specific cytolytic T cell clones that function in vivo.
The gag membrane protein gP85gag, encoded by Moloney murine leukemia virus (M-MLV), was identified as a target molecule recognized by Moloney murine sarcoma virus--M-MLV (M-MSV--M-MLV)-specific cytolytic T lymphocyte (CTL) clones. Target cells infected with Ab-X-MLV, an M-MLV-derived mutant virus not encoding gP85gag, were not lysed by the CTL clones. The same CTL clones were shown previously to induce the destruction of M-MLV-induced tumor cells in the peritoneal cavity. We have now characterized CTL-resistant antigen-loss tumor cell variants that have lost the surface antigen, but which retain transcriptionally silent M-MLV genomes. A cloned antigen-loss variant that reverted in vitro to the CTL-susceptible phenotype reexpressed M-MLV genomes that had undergone an insertion event in the region of the viral DNA coding for the gag membrane protein. Intravenous injection of virus-specific CTL clones inhibited tumor formation in mice injected subcutaneously with M-MSV--M-MLV.
D000818:Animals; D000956:Antigens, Viral / Q000276:immunology*; D002999:Clone Cells / Q000276:immunology; D005260:Female; D015683:Gene Products, gag; D005814:Genes, Viral; D007167:Immunotherapy; D007942:Leukemia, Experimental / Q000209:etiology / Q000276:immunology; D051379:Mice; D008815:Mice, Inbred Strains; D008979:Moloney murine leukemia virus / Q000235:genetics / Q000276:immunology*; D008980:Moloney murine sarcoma virus / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014764:Viral Proteins / Q000276:immunology*
D000956:Antigens, Viral; D015683:Gene Products, gag; D014764:Viral Proteins