Membrane antigen of bovine papilloma virus induced fibroma cells

A surface antigen on live, unfixed, bovine papilloma virus induced fibroma cells was demonstrated with the indirect immunofluorescence (IF) test. Sera from calves with experimentally produced fibromas contained antibody to cultured fibroma cells; this indicated exposure to the same antigen. No activity could be demonstrated with the same sera tested against cultured normal dermal fibroblasts. The serum antibody activity could be removed by absorption with tumor cells but not with normal cells. Cultured fibroma cells were negative for viral antigens by the direct IF test and electron microscopic examination. Sequential antibody titers indicated correlation with onset of tumor growth but not with progression or regression of fibromas.