Transmission electron microscopy on simian immunodeficiency virus-infected cocultures of vervet monkeys

Healthy African green monkeys are the natural reservoirs for certain HIV-related SIVs. More research is now focused on these nonhuman primates that are asymptomatic, so as to answer questions of origins, pathogenesis and therapy with respect to HIV in man. The present study involves the isolation and subsequent co-cultivation of SIV variants from two healthy vervet monkeys (Cercopithecus aethiops pygerythrus). Western Blots (New LAV Blot 1 and New LAV Blot 2, Pasteur) revealed sero cross-reactivity of each monkey to major HIV-1 and HIV-2 antigens. Freshly isolated peripheral blood mononuclear cells of each monkey were co-cultivated with the CEMss and M4C8 T-cell lines. The cocultures were incubated in CO2 at 37 degrees C for 3-4 days, before refeeding with RPMI 1640, phytohaaemagglutinin and interleukin-2. Cytopathic effects in the cocultures were observed 14 days post-infection, with syncytia and enlarged, granular cells being predominant in both of the cell-lines used. The presence and morphology of viral-like particles were observed by transmission electron microscopy. Immunocytochemistry and in situ hybridization may help in characterization of the particles, as well as aid in determining localization and concentration in vitro.