title: Interleukin-10 but not Transforming Growth Factor beta inhibits murine activated macrophages Paracoccidioides brasiliensis killing: effect on H2O2 and NO production.
abstract: Paracoccidioidomycosis is caused by the thermally dimorphic fungus Paracoccidioides brasiliensis (P. brasiliensis). Most often, this mycosis runs as a chronic progressive course affecting preferentially the lungs. In vitro fungicidal activity against a high virulent strain of P. brasiliensis by murine peritoneal macrophages preactivated with IFN-gamma or TNF-alpha is high and correlates with increased NO and H2O2 production. Within this context, the purpose of this work was to study the role of suppressor cytokines, such as IL-10 and TGF-beta, in this process. Incubation of either IFN-gamma or TNF-alpha with IL-10 inhibits fungicidal activity of these cells. However, TGF-beta had no effect on fungicidal activity of IFN-gamma or TNF-alpha-activated macrophages. The suppression of fungicidal activity by IL-10 correlated with the inhibition of NO and H2O2 production supporting the involvement of these metabolites in P. brasiliensis killing. These results suggest that IL-10 production in vivo could represent an evasion mechanism of the fungus to avoid host immune response.
authors.affiliation: UNESP-Univ Estadual Paulista, Instituto de Biociências-Campus Botucatu, Departamento de Microbiologia e Imunologia, CEP 18618-000, SP, Brazil.
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Moreira
authors.forename: Luciane Alarcão
authors.initials: LA
authors.lastname: Dias-Melicio
authors.forename: Angela Maria Victoriano Campos
authors.initials: AM
authors.lastname: Soares
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D006861:Hydrogen Peroxide / Q000378:metabolism*; D007371:Interferon-gamma / Q000037:antagonists & inhibitors / Q000276:immunology; D016753:Interleukin-10 / Q000276:immunology / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects* / Q000276:immunology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009569:Nitric Oxide / Q000378:metabolism*; D010228:Paracoccidioides / Q000502:physiology*; D010229:Paracoccidioidomycosis / Q000188:drug therapy / Q000276:immunology* / Q000382:microbiology; D016212:Transforming Growth Factor beta / Q000276:immunology* / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors / Q000276:immunology
chemical_list: D016212:Transforming Growth Factor beta; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D009569:Nitric Oxide; D007371:Interferon-gamma; D006861:Hydrogen Peroxide