Search for mammalian type-C retrovirus polypeptides on infected animal cells and human tumor cell lines using interspecies-reacting antibodies.
Cells producing endogenous and exogenous type-C retroviruses of murine, feline and primate origin were evaluated for expression of those virus-specific cell-surface antigens which cross-react with antibodies to interspecies determinants of mammalian type-C viral polypeptides. Surface polypeptides of cells replicating endogenous and exogenous type-C retroviruses were iodinated by the lactoperoxidase method. Labelled antigens were immunoprecipitated and analyzed in polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. This method detected gp71 and less frequently p15E/p12E on the surface of virus-producing cells; in addition, p27 was found on F422 cells replicating feline leukemia virus. Antibodies to the membrane protein p15E displayed the broadest cross-reactivity but only antibodies to gp71 mediated complement-dependent interspecies cell lysis. The pattern of cross-reactivity reflected known genetic relationships among these mammalian viruses. Although antiserum to the simian sarcoma virus complex (SSV) was strongly cytotoxic to some human tumor cell lines, this reactivity could not  be attributed to antibodies cross-reacting with SSV gp71.
D000818:Animals; D000951:Antigens, Neoplasm / Q000032:analysis; D000956:Antigens, Viral / Q000032:analysis; D002460:Cell Line; D002462:Cell Membrane / Q000276:immunology; D003429:Cross Reactions; D003601:Cytotoxicity Tests, Immunologic; D006023:Glycoproteins / Q000276:immunology; D006801:Humans; D009369:Neoplasms / Q000382:microbiology*; D009374:Neoplasms, Experimental / Q000382:microbiology; D011233:Precipitin Tests; D012190:Retroviridae / Q000032:analysis* / Q000276:immunology; D014764:Viral Proteins / Q000032:analysis* / Q000276:immunology
D000951:Antigens, Neoplasm; D000956:Antigens, Viral; D006023:Glycoproteins; D014764:Viral Proteins