Effects of the nef and tat genes of the human immunodeficiency virus type 1 on rat pheochromocytoma cells of line PC12

The regulatory genes nef and tat of the human immunodeficiency virus type 1 (HIV-1) were transferred into the rat pheochromocytoma cells (line PC12) u nder the control of the eukaryotic promoters. Proliferative activity of the PC12 cells transfected with the tat HIV-1 gene was substantially increased as compared to the control, Conversely, the nef gene introduced into the c ultivated PC12 cell caused inhibition of their proliferative activity and f ormation of cell agglomerates resembling in morphology the multinuclear syn cytial cells. Thus, our results suggest that the tnt gene activates prolife ration of the cultivated PC12 cells, whereas the nef gene inhibits prolifer ation of the same cells. We have obtained for the first time a direct indic ation for the possible role of the nef gene in formation of multinuclear T- lymphocyte and macrophage syncytium in HIV-1-infected patients. The HIV-1 n ef and tat genes had no significant effect on the neuronal differentiation of the PC12 cells induced by the nerve growth factor (NGF).