Effect of immune activation induced by Cryptosporidium parvum whole antigen on in vitro human immunodeficiency virus type 1 infection.
Previous epidemiologic investigations have suggested that persons with AIDS who are infected with Cryptosporidium parvum have a shorter survival time than those with other opportunistic infections. In this study, the effect of immune activation by a crude Cryptosporidium whole antigen on human immunodeficiency virus type 1 (HIV-1) infection was evaluated. Peripheral blood mononuclear cells from healthy persons without HIV-1 infection had increased proliferative and cytokine (interleukin-4, interferon-gamma, and tumor necrosis factor [TNF]-alpha) responses to stimulation with the crude Cryptosporidium whole antigen. This stimulation increased HIV-1 p24 antigen production in in vitro infection by>30-fold. A similar increase in p24 production was also seen when stimulation was done after cells were infected with HIV-1. Neutralization of TNF-alpha reduced Cryptosporidium antigen-induced p24 production by >50%. Results of this study suggest that Cryptosporidium-induced immune activation may be a cofactor in regulating HIV-1 production.
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Immunology Branch, Division of Parasitic Diseases, Centers for Disease Control and Prevention, Chamblee, GA 30341, USA.
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D000818:Animals; D000953:Antigens, Protozoan / Q000276:immunology*; D002478:Cells, Cultured; D016785:Cryptosporidium parvum / Q000276:immunology*; D016207:Cytokines / Q000096:biosynthesis; D016655:HIV Core Protein p24 / Q000096:biosynthesis*; D015497:HIV-1 / Q000502:physiology*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000276:immunology* / Q000821:virology*; D008213:Lymphocyte Activation; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
D000953:Antigens, Protozoan; D016207:Cytokines; D016655:HIV Core Protein p24; D014409:Tumor Necrosis Factor-alpha