ACTIVATION OF HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 IN MONOCYTOID CELLSBY THE PROTOZOAN PARASITE LEISHMANIA-DONOVANI

In this study, we demonstrated that the protozoan parasite Leishmania donovani and one of its major surface molecules, the lipophosphoglycan (LPG), can induce human immunodeficiency virus type 1 (HIV-1) express ion in U1 and OM-10.1, two cell lines of monocytoid origin latently in fected with HIV-1. Treatment of U1 cells with various concentrations o f LPG (1, 5, and 10 mu M) resulted in a dose-dependent secretion of tu mor necrosis factor alpha (TNF-alpha). Suppression of LPG-induced HIV- 1 expression by polyclonal anti-TNF-alpha antibodies further confirmed the involvement of this cytokine. Results from these studies indicate that the protozoan parasite L. donovani can induce the secretion of T NF-alpha that will function in an autocrine or paracrine manner to upr egulate HIV-1 expression. Our data suggest for the first time that thi s protozoan parasite can be viewed as a potential cofactor in the path ogenesis of AIDS.