Common Cell-Surface Antigen Associated with Murine and Feline C-Type RNA Leukemia Viruses

A new common cell-surface antigen associated with murine and feline C-type RNA leukemia viruses was demonstrated by the use of rabbit antiserum against feline leukemia virus and the indirect membrane immunofluorescence test. Common cell-surface antigen was found in all leukemias of all strains of mice tested, in normal lymphoid tissues of Gross-positive (high incidence of leukemia) mouse strains AKR, AKR.H-2^b, C58, and NZB, in cultured rat fibroblasts infected with Rauscher virus, in cultured feline fibroblasts infected with feline leukemia virus, and in spontaneous feline lymphosarcoma. The antigen was not demonstrable in normal adult and fetal tissues of Gross-negative mouse strains or in tissues and cultured fibroblasts derived from normal rats and normal cats. The immunoferritin study of murine leukemia cells revealed that the antigen was located on the cell surface in discrete areas; budding and C-type RNA viral envelope was not labeled as antigen site. The distribution of common cell-surface antigen on murine and feline leukemias, as well as on normal lymphoid tissues of Gross-positive mouse strains, indicates the presence of an antigen distinct from any cell-surface antigen heretofore shown to be associated with, or specified by, mammalian C-type RNA viruses.