title: Activation of human immunodeficiency virus type 1 in monocytoid cells by the protozoan parasite Leishmania donovani.
abstract: 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) expression in U1 and OM-10.1, two cell lines of monocytoid origin latently infected with HIV-1. Treatment of U1 cells with various concentrations of LPG (1, 5, and 10 microM) resulted in a dose-dependent secretion of tumor 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 TNF-alpha that will function in an autocrine or paracrine manner to upregulate HIV-1 expression. Our data suggest for the first time that this protozoan parasite can be viewed as a potential cofactor in the pathogenesis of AIDS.
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000503:physiopathology; D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D002454:Cell Differentiation; D002460:Cell Line; D006028:Glycosphingolipids / Q000494:pharmacology*; D015497:HIV-1 / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D006801:Humans; D007893:Leishmania donovani / Q000502:physiology*; D009000:Monocytes; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000276:immunology; D014775:Virus Activation / Q000187:drug effects; D017735:Virus Latency
chemical_list: D000906:Antibodies; D006028:Glycosphingolipids; D014409:Tumor Necrosis Factor-alpha; C008290:lipophosphonoglycan; D013755:Tetradecanoylphorbol Acetate