title: Apoptosis modulation in mononuclear cells recovered from individuals exposed to Plasmodium falciparum infection.
abstract: In endemic areas, asymptomatic infection by the malaria parasite Plasmodium falciparum was found associated with elevated percentages of human host's mononuclear cell spontaneous in-vitro apoptosis. In Dielmo, a village where malaria is holoendemic, apoptosis was age-and parasite-dependent. In-vitro exposure of peripheral blood mononuclear cells (PBMC) to the parasite extract induced a marked increase in the mononuclear cell membrane expression of functional CD95 antigen: a 3-h exposure of the mononuclear cells to anti-CD95 antibodies led to a detectable increase in the mean percentage of apoptotic nuclei found in the cultures carried out in the presence of P. falciparum extracts compared to control cultures. IL-2, IL-4, IL-6 and IL-10 promoted the viability of PBMC in cultures while IL-1alpha or IFN-gamma had no obvious impact and TNFalpha gave conflicting results. IL-2 was the most efficient cytokine at rescuing PBMC from cell death and this effect was associated with a strong increase in T cell activation. In contrast, IL-4 and IL-10 had no such effect on T cell activation, hence they acted as survival factors and not through their mitogenic activity. Taken together, these different observations suggested that the levels of in-vitro apoptosis observed were not only associated with parasite infection, but also potentially modulated by the human host through different pathways.
authors.affiliation: Laboratoire d'Immunologie; Laboratoire d'Epidémiologie, Institut Pasteur, BP 220, Dakar, Sénégal.
authors.forename: A T
authors.initials: AT
authors.lastname: Balde
authors.forename: G
authors.initials: G
authors.lastname: Aribot
authors.forename: A
authors.initials: A
authors.lastname: Tall
authors.forename: A
authors.initials: A
authors.lastname: Spiegel
authors.forename: C
authors.initials: C
authors.lastname: Roussilhon
mesh_terms: D000818:Animals; D000906:Antibodies / Q000276:immunology; D000953:Antigens, Protozoan / Q000494:pharmacology; D017209:Apoptosis / Q000276:immunology*; D002462:Cell Membrane / Q000276:immunology; D016922:Cellular Senescence; D006801:Humans; D007378:Interleukins / Q000494:pharmacology; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000276:immunology*; D008213:Lymphocyte Activation; D016778:Malaria, Falciparum / Q000097:blood / Q000276:immunology* / Q000469:parasitology; D010963:Plasmodium falciparum / Q000276:immunology; D012675:Senegal; D013601:T-Lymphocytes / Q000276:immunology; D019014:fas Receptor / Q000032:analysis / Q000276:immunology
chemical_list: D000906:Antibodies; D000953:Antigens, Protozoan; D007378:Interleukins; D019014:fas Receptor