CALBINDIN D-28K-CONTAINING NEURONS, AND NOT HSP70-EXPRESSING NEURONS,ARE MORE RESISTANT TO HIV-1 ENVELOPE (GP120) TOXICITY IN CORTICAL CELL-CULTURES

HIV-1-associated cognitive/motor complex is one of the major neurologi cal complications of AIDS and is associated with neuronal loss, Gp120, the HIV envelope protein, is toxic for neurons in cultures and produc es a rise in intracytosolic calcium, This neurotoxicity is dose-depend ent and time-dependent, We evaluated the selective gp120 toxicity in p rimary neuronal cultures for calbindin-free and calbindin-containing n eurons with semi-quantitative immunocytochemistry using an anti-calbin din D-28K monoclonal antibody, The number of immunolabelled neurons wa s inversely correlated to neuronal survival, In cultures exposed to gp 120 (100 pM) for 24 hr the neuronal survival of initial platings was 1 9.7 +/- 2,1% and the percentage of neuronal survival was 84.6 +/- 4.9% in control cultures exposed to the vehicle, The corresponding percent ages of immunolabelled neurons were 85.0 +/- 2.1% in treated cultures and 23.6 +/- 3.1% in control cultures (P < 0.001), The expression of h eat shock proteins by heating cell cultures did not protect neurons fr om gp120 toxicity, These results suggest that calbindin D,,,-containin g neurons are more resistant to gp120-toxicity in this cell culture sy stem. (C) 1995 Wiley-Liss, Inc.