DIRECT CYTOTOXICITY OF HIV-1 ENVELOPE PROTEIN GP120 ON HUMAN NT NEURONS

A new in vitro system comprising a pure population of neurons, human N T cells, was used to characterize the direct neurotoxic effect of HIV- 1 envelope protein gp120. Cytotoxicity exposure to recombinant gp120 i n the presence or absence of other reagents. Treatment of mature NT ne urons with various doses of gp120 for 24 h caused a decrease of up to 27% in the number of viable cells. This neurotoxicity was abolished by co-treatment with either D-2-amino-5-phosphonopentanoic acid (APV), M K801 or nimodipine, or by culturing cells in a Ca2+-free environment. Taken together, these data indicate that gp120 exerts a direct neuroto xic effect by acting through NMDA receptors and Ca2+ channels.