Immunofluorescence studies on the association between a C-type oncornavirus and renal glomerulopathy in Praomys (Mastomys) natalensis

During its lifespan, the multi-mammate mouse Praomys (Mastomys) natalensis develops a great variety of neoplastic and non-neoplastic lesions. Among the non-neoplastic lesions, renal lesions are predominant. From light microscopic, electron microscopic, and immunofluorescence studies, Mastomys glomerulopathy appeared to be comparable to the immune complex glomerulonephritis in several mouse strains. Oncornaviral antigens are demonstrated in these immune complexes in AKR and NZB mice. Therefore, renal tissues of aged Mastomys were screened by the immunofluorescence technique for the presence of oncornaviral antigens by using polyvalent antisera against murine and feline leukemia viruses. Viral antigens were detectable in glomeruli of aged mastomys, but not in kidneys of young mastomys. Infectious virus could be demonstrated in cell-free spleen extracts of three Mastomys. This virus does not grow in Mastomys or mouse embryonic fibroblasts but replicates in the murine BALB 3T3 cell line.