Expression of Murine Leukemia Virus Structural Antigens on the Surface of Chemically Induced Murine Sarcomas

Cultured cells of different chemically-induced C57BL/6N murine sarcomas produced variable amounts of infectious murine leukemia virus (MuLV) and contained proportional amounts of MuLV structural components as determined by radioimmunoassay. Monospecific antisera directed against the major MuLV glyco-protein (gp71), the major internal antigen (p30), and the ribonucleoprotein (p10) were capable of mediating tumor cell lysis in the presence of complement, suggesting that these viral structural components were localized at least in part to the cell surface. Membrane immunofluorescence studies with MuLV p30 antiserum confirmed surface localization. Addition of MuLV p30 polypeptide to normal cells and tumor cells enhanced the cytotoxicity of MuLV p30 antiserum. Studies are presented which suggest that the presence of MuLV structural components on cell surfaces can be independent of virus production and cellular transformation.