title: IL-10 producing CD8+ T cells in human infection with Leishmania guyanensis.
abstract: Cytokines are increasingly recognized as important components of the cellular immune responses to intracellular pathogens. In this study, we analyzed the production of TGF-beta, IL-10 and IFN-gamma by PBMC of unexposed naïve subjects and LCL patients after stimulation with live Leishmania guyanensis (L.g.). We demonstrated that IFN-gamma is produced in controls and LCL patients, IL-10 only in LCL patients and TGF-beta only in naïve subjects. Furthermore, in naive subjects, neutralization of TGF-beta induced IL-10 production. IL-10 produced in naïve subjects when TGF-beta is neutralized or in LCL patients did not modify the IFN-gamma production but inhibit reactive nitrogen species production. Analysis of the phenotype of IL-10 producing cells in naive subjects when TGF-beta is neutralized clearly showed that they are memory CD45RA- CD8+ T cells. In LCL patients, IL-10 producing cells are both CD45RA- CD4 and CD8+ T cells. The role of these IL-10 producing CD8+ T cells in the development of the diseases should be carefully evaluated.
authors.affiliation: Immunologie des Leishmanioses, Institut Pasteur de la Guyane, 97306 Cayenne, French Guiana.
authors.forename: Eliane
authors.initials: E
authors.lastname: Bourreau
authors.forename: Catherine
authors.initials: C
authors.lastname: Ronet
authors.forename: Pierre
authors.initials: P
authors.lastname: Couppié
authors.forename: Dominique
authors.initials: D
authors.lastname: Sainte-Marie
authors.forename: Fabienne
authors.initials: F
authors.lastname: Tacchini-Cottier
authors.forename: Pascal
authors.initials: P
authors.lastname: Launois
mesh_terms: D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002460:Cell Line; D002478:Cells, Cultured; D006801:Humans; D007156:Immunologic Memory; D016753:Interleukin-10 / Q000096:biosynthesis*; D018334:Leishmania guyanensis / Q000472:pathogenicity*; D007897:Leishmaniasis, Mucocutaneous / Q000175:diagnosis / Q000276:immunology* / Q000469:parasitology; D017493:Leukocyte Common Antigens / Q000378:metabolism; D008213:Lymphocyte Activation
chemical_list: D016753:Interleukin-10; D017493:Leukocyte Common Antigens