Detection of avian and mammalian oncogenic RNA viruses (oncornaviruses) by immunofluorescence.

Abstract

Summary The indirect immunofluorescence and immunofluorescence absorption tests were used to determine the presence and intracellular deposition of viral antigens in cells infected with avian, murine, hamster, and feline oncornaviruses. In all instances, viral antigens were restricted to the cytoplasm; nuclear fluorescence was not observed. Screening of murine neoplasms by immunofluorescence and immunofluorescence absorption showed ( a ) that murine leukemia virus and murine mammary tumor virus (MTV) were serologically unrelated; ( b ) that murine leukemia virus was widespread throughout the mouse population and occurred in a variety of tumors and leukemias of mice from both high- and low-leukemia-incidence strains; and ( c ) that MTV was restricted to a few types of neoplastic tissues, which occurred only in mice of high-mammary-tumor-incidence strains. With the immunofluorescence absorption technique, MTV, as well as murine leukemia virus, could be detected in the spleen of individual mice from high-incidence strains. The amount of viral antigen in the spleen of mice from crosses of high-mammary-tumor strains (or high-leukemia strains) with mice of low-incidence strains was intermediate between that of the parental strains. A serological comparison of murine oncornaviruses with those of the chicken, hamster, and cat revealed that ( a ) the avian and mammalian oncornaviruses are serologically unrelated to each other; ( b ) oncornaviruses from the chicken, mouse, hamster, and cat contain species-specific viral antigens that are serologically distinguishable (however, the leukemia and sarcoma viruses within a single species are antigenically indistinguishable); ( c ) the mammalian leukemia-sarcoma viruses share at least one common antigen; and ( d ) the mouse MTV is serologically unrelated to all other oncornaviruses.