Studies of Murine Leukemia Viruses I. Detection of Moloney and Rauscher Leukemia Viruses by Indirect Immunofluorescence.

Abstract

Summary Specific cytoplasmic fluorescence resulted when RLV- or MLV-infected cells were treated with their respective antiviral sera in the indirect immunofluorescence test. The fluorescence was especially intense in the cytoplasm of megakaryocytes, where abundant virus particles were seen by electron microscopy. No antigenic cross reactivity of RLV and MLV could be demonstrated by this test. Inoculation of mouse fetal cell monolayers with RLV or MLV led to the appearance of immunofluorescent cells, which increased in percentage with increasing length of incubation time. Electron microscopy of the infected cells demonstrated that the initial appearance of virus at cell membranes was related to the appearance of fluorescence and that increasing numbers of virus-forming cells and concentrations of virus particles between and within cells were associated with the increasing percentage of fluorescent cells. The indirect immunofluorescence method is useful for detection of MLV and RLV and may be applicable to the quantitative assay of these viruses in cell culture.