title: Leishmania-specific T cells expressing interferon-gamma (IFN-gamma) and IL-10 upon activation are expanded in individuals cured of visceral leishmaniasis.
abstract: Peripheral blood mononuclear cells (PBMC) from patients who have recovered from visceral leishmaniasis often respond to Leishmania antigens in vitro by production of both IL-4, IFN-gamma and IL-10. In order to establish the cellular sources of these cytokines, we activated cells from individuals with a history of visceral leishmaniasis with Leishmania antigen for 6 days in culture, and identified cytokine production at the single-cell level by flow cytometry. The cytokines were only found in CD3+ cells and among these mainly within the CD4+ subset. The percentage of cytokine-producing cells was compared in Leishmania-activated PBMC cultures from the previous patients and from individuals living in a village where leishmaniasis does not occur. The percentage of IL-10- and IFN-gamma-containing cells was significantly higher in the previous patients than in the controls, indicating that Leishmania-specific T cells producing IL-10 and/or IFN-gamma had been expanded as a result of the infection. The cytokine-producing cells in the previous patients could be divided into three types: (i) cells producing IFN-gamma only; (ii) cells producing IL-4 only; and (iii) cells producing IFN-gamma and IL-10 simultaneously. The first and second group of cells can be described as Th1- and Th2-type cells, respectively. The third group could be a regulatory subset of T cells important for maintaining a balance between Th1- and Th2-type cells in these individuals.
authors.affiliation: Centre for Medical Parasitology at Laboratory Centre and RHIMA Centre, Copenhagen University Hospital (Rigshospitalet), Denmark. kkcmp@rh.dk
authors.forename: K
authors.initials: K
authors.lastname: Kemp
authors.forename: M
authors.initials: M
authors.lastname: Kemp
authors.forename: A
authors.initials: A
authors.lastname: Kharazmi
authors.forename: A
authors.initials: A
authors.lastname: Ismail
authors.forename: J A
authors.initials: JA
authors.lastname: Kurtzhals
authors.forename: L
authors.initials: L
authors.lastname: Hviid
authors.forename: T G
authors.initials: TG
authors.lastname: Theander
mesh_terms: D000818:Animals; D006801:Humans; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000096:biosynthesis*; D016753:Interleukin-10 / Q000096:biosynthesis*; D015847:Interleukin-4 / Q000096:biosynthesis; D007893:Leishmania donovani / Q000276:immunology*; D007898:Leishmaniasis, Visceral / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology
chemical_list: D016753:Interleukin-10; D015847:Interleukin-4; D007371:Interferon-gamma