HIV-1 inhibits Leishmania-induced cell proliferation but not production of interleukin-6 and tumour necrosis factor alpha.
The immune response of normal human peripheral blood mononuclear cells (PBMC) after stimulation with human immunodeficiency virus-1 (HIV-1) antigens plus Leishmania donovani promastigotes in vitro was investigated. HIV-1-antigen stimulation of PBMC did not induce the intracellular accumulation of interleukin-6 (IL-6), tumour necrosis factor-alpha (TNF-alpha), or interferon-gamma (IFN-gamma). However, cells stimulated with L. donovani antigens exhibited the production of IL-6 and TNF-alpha, but not IFN-gamma. Furthermore, co-stimulation of PBMC with HIV-1 antigen plus L. donovani resulted in the intracellular accumulation of IL-6 and TNF-alpha comparable to that of cells that were activated with L. donovani antigen alone. Heat-inactivated HIV-1 antigen did not appear to induce or suppress cytokine production by PBMC. However, the same HIV antigens did suppress L. donovani-induced proliferation as well as PPD-induced proliferation in a dose-dependent fashion. Elevated levels of serum cytokines have been demonstrated in patients with HIV infection indicating their role in the pathogenesis of HIV-associated immunosuppression. The results may partially support the idea that the abnormally increased cytokine levels in the sera of HIV-infected subjects is due to the various opportunistic pathogens that these patients contract, rather than a response to HIV antigens. As cytokines have been shown to up-regulate HIV replication, the data suggest a role for opportunistic infections in cytokine-induced transactivation of HIV-1 and disease progression.
Wolday
D
D
Department of Medical Microbiology and Parasitology, Addis Ababa University, Faculty of Medicine, Ethiopia.
Akuffo
H
H
Britton
S
S
Hathaway
A
A
Sander
B
B
D017088:AIDS-Related Opportunistic Infections / Q000276:immunology; D000293:Adolescent; D000328:Adult; D000818:Animals; D005260:Female; D015488:HIV Antigens; D015658:HIV Infections / Q000276:immunology; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D007108:Immune Tolerance; D066298:In Vitro Techniques; D015850:Interleukin-6 / Q000096:biosynthesis; D007700:Kinetics; D007893:Leishmania donovani / Q000276:immunology*; D007898:Leishmaniasis, Visceral / Q000150:complications / Q000276:immunology; D007963:Leukocytes, Mononuclear / Q000276:immunology*; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
D015488:HIV Antigens; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha