HIV-1 envelope protein gp120 affects phenotype and function of monocytes in vitro

We investigated the effect of human immunodeficiency virus type 1 (HIV-1) recombinant gp120 (rec.gp120) on phenotype and function of cultured monocytes. Rec.gp120 significantly reduced the accessory function of monocytes to stimulate autologous lymphocytes with anti-CD3, the Fc receptor-mediated chemiluminescence of monocytes, and the expression of CD4 and Fc receptor I/II, while the expression of the monocyte marker CD14 and major histocompatibility complex class I and II was not influenced. According to these phenotypic results, preincubation of monocytes with rec.gp120 depressed anti-CD3 antibody-induced T cell stimulation and Fc receptor-mediated phagocytosis as determined by chemiluminescence. Interferon-gamma release of lymphocytes induced by purified protein derivative of tuberculin was enhanced by gp120. These effects of isolated gp120 on monocyte immune functions in vitro might contribute to the understanding of the pathophysiology of HIV-1 infection in vivo.