LASER CYTOMETRIC ANALYSIS OF FIV-INDUCED INJURY IN ASTROGLIA

Glia are the predominant brain cells infected by the lentiviruses huma n immunodeficiency virus (HIV) and feline immunodeficiency virus (FIV) . The importance of astrocytes in maintenance of central nervous syste m homeostasis suggests that astrocytes are likely to play a strategic role in the progression of neurological disease in lentiviral-infected patients. In consideration of this postulate, the ability of FIV to c ause injury by infection of cultured feline astroglia was examined via vital fluorescence assays. Intracellular Ca2+ homeostasis, plasma mem brane permeability and fluidity, and cytosolic glutathione (GSH) level s were evaluated. Although basal intracellular Ca2+ was not significan tly different between groups, FIV-infected astroglia displayed both a significant delay in development of peak Ca2+ levels following ionopho re application and a decrease in the amount of Ca2+ released from intr acellular stores. Plasma membrane lipid mobility was increased in FIV- infected cells within 24 h of infection. Glutathione levels were affec ted in a dose dependent fashion. With a standard viral inoculum there was a decrease in GSH which became significant after 8 days postinfect ion With a high inoculum dose there was rapid loss of cell viability w ith an increase in GSH in surviving cells. We have identified several cellular processes altered in FN-infected astroglia and our findings s uggest that FIV-infection of feline astroglia affects cellular membran es, both structurally and functionally. (C) 1995 Wiley-Liss, Inc.