title: Antibody in cats to mammalian RNA tumor virus interspecies antigens.
abstract: The studies were undertaken to determine whether the cat, a mammalian species that carries xenotropic endogenous C-type virus(es) and in addition undergoes horizontally transmitted oncogenic C-type RNA tumor virus infections, responds immunologically to the mammalian C-type virus interspecies antigens. Sera from normal cats and from cats with spontaneous or virus-induced neoplasms were examined for antibodies to interspecies antigen antigen by complement-fixation inhibition, by inhibition of the paired radioiodine-labeled antibody technique (PRILAT inhibition), and by two-step radioimmunoelectrophoresis. Using three separate complement-fixation inhibition systems designed to detect antibodies to interspecies antigen(s), 23 of 23 sera from tumor-bearing cats and 24 of 31 sera from normal cats were positive in both systems. The negative sera were from germ-free cats. Among the 49 positive sera, 47 yielded titers of 1:16 or greater by one or more complement-fixation inhibition tests. Of these 47 sera, 42 were positive by the paired radioiodine-labeled antibody technique inhibition test; the 5 paired radioiodine-labeled antibody technique-negative sera were from normal specific-pathogen-free cats. Direct reaction with the interspecies determinant on the p30  protein from Rauscher murine leukemia virus by immunoglobulin from cats immunized with feline leukemia virus was shown by two-step radioimmunoelectrophoresis. The feline antibody was also identified as an immunoglobulin by column chromatography and two-step radioimmunoelectrophoresis. These antibodies did not fix guinea pig complement during reaction with the interspecies antigen. That other mammals may produce similar noncomplement-fixing (guinea pig) antibodies to RNA tumor virus antigens is likely.
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis*; D000956:Antigens, Viral; D002371:Cat Diseases / Q000276:immunology; D002415:Cats / Q000276:immunology*; D003168:Complement Fixation Tests; D000939:Epitopes; D005856:Germ-Free Life; D006168:Guinea Pigs / Q000276:immunology; D007122:Immunoelectrophoresis; D005256:Leukemia Virus, Feline / Q000276:immunology; D009369:Neoplasms / Q000662:veterinary; D011863:Radioimmunoassay; D011925:Rauscher Virus / Q000276:immunology; D012190:Retroviridae / Q000276:immunology*; D013045:Species Specificity
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D000939:Epitopes