Influência do receptor Toll-like 2 na defesa do hospedeiro contra o fungo Sporothrix schenckii
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Data
2012-11-09
Autores
Negrini, Thais de Cássia [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
A esporotricose é uma infecção causada pelo fungo dimórfico Sporothrix schenckiii, o qual contamina o hospedeiro através de locais com pequenos traumas, causando lesões cutâneas, subcutâneas que podem se disseminar para outros tecidos. Os mecanismos imunológicos envolvidos na prevenção e controle da esporotricose sugerem que a imunidade mediada por células apresenta um importante papel na proteção do hospedeiro contra S. schenckii. Os receptores Toll-like (TLR), presentes nas células do sistema imune inato, destacam-se pelo seu papel central na ligação de patógenos e iniciação da resposta imune. A ativação desses receptores por padrões moleculares associados à patógenos (PAMPs) induz a fagocitose, a liberação de citocinas e mediadores químicos que atuam no sistema imune eliminando ou favorecendo a infecção. O TLR-2 está envolvido na resposta do hospedeiro contra uma variedade de fungos. Portanto, o objetivo do presente estudo foi avaliar a participação do TLR-2 na resposta imunológica induzida pelo S. schenckii. Foram utilizados camundongos C57BL/6 (WT) e C57BL/6 TLR-2 Knockout (TLR-2-/-) para que se conseguisse verificar, durante um período de 10 semanas de infecção esporotricótica, a influência do TLR-2 na produção das citocinas IL-1β, IL-12 e TNF-α por macrófagos; a estimulação dos macrófagos através da liberação de NO, a participação do TLR-2 na geração dos perfis celulares Th1, Th2 e Th17 e, por fim, a influência desse receptor na produção de IFN-γ, IL-6, IL-10, IL-4, IL-17 e TGF-β. Entre os antígenos do fungo S. schenckii utilizados como estímulo nas culturas celulares, verificou-se que o antígeno lipídico é o mais eficaz na capacidade de estimular a produção dos mediadores...
Sporotrichosis is an infection caused by the dimorphic fungus Sporothrix schenckii, which infects the host through local minor trauma, causing skin and subcutaneous lesions which can spread to other tissues. The immunological mechanisms involved in sporotrichosis prevention and control suggest that cell-mediated immunity plays an important role in protecting the host against S. schenckii. The Toll-like receptors (TLR), found on innate immune system cells, for their central role in pathogen-binding and immune response initiation. The activation of these receptors by pathogen-associated molecular patterns (PAMPs) induces phagocytosis and the release of chemical mediators and cytokines which direct the immune system in favoring or eliminating the infection. TLR-2 is involved in host responses against a variety of fungi. Therefore, the aim of this study was to evaluate the involvement of TLR-2 in the immune response induced by S. schenckii. C57BL/6 mice (WT) and C57BL/6 TLR-2 knockout (TLR-2-/-) were used in order to evaluate, over a period of 10 weeks of sporotrichotic infection, the influence of TLR-2 over macrophages production of the cytokines IL-1β , IL-12 and TNF-α, their stimulation level by NO release, the involvement of TLR-2 in the generation of Th1, Th2 and Th17 cell profiles and, finally, the influence of this receptor in the production of IFN -γ, IL-6, IL-10, IL-4, IL-17 and TGF-β. Among all the S. schenckii antigens used as stimulus in cell cultures, it was found that the lipid antigen is the most effective in regard... (Complete abstract click electronic access below)
Sporotrichosis is an infection caused by the dimorphic fungus Sporothrix schenckii, which infects the host through local minor trauma, causing skin and subcutaneous lesions which can spread to other tissues. The immunological mechanisms involved in sporotrichosis prevention and control suggest that cell-mediated immunity plays an important role in protecting the host against S. schenckii. The Toll-like receptors (TLR), found on innate immune system cells, for their central role in pathogen-binding and immune response initiation. The activation of these receptors by pathogen-associated molecular patterns (PAMPs) induces phagocytosis and the release of chemical mediators and cytokines which direct the immune system in favoring or eliminating the infection. TLR-2 is involved in host responses against a variety of fungi. Therefore, the aim of this study was to evaluate the involvement of TLR-2 in the immune response induced by S. schenckii. C57BL/6 mice (WT) and C57BL/6 TLR-2 knockout (TLR-2-/-) were used in order to evaluate, over a period of 10 weeks of sporotrichotic infection, the influence of TLR-2 over macrophages production of the cytokines IL-1β , IL-12 and TNF-α, their stimulation level by NO release, the involvement of TLR-2 in the generation of Th1, Th2 and Th17 cell profiles and, finally, the influence of this receptor in the production of IFN -γ, IL-6, IL-10, IL-4, IL-17 and TGF-β. Among all the S. schenckii antigens used as stimulus in cell cultures, it was found that the lipid antigen is the most effective in regard... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Esporotricose, Fungos, Citocinas, Lupus, Resposta imune, Antigenos de fungos, Fungos patogenicos
Como citar
NEGRINI, Thais de Cássia. Influência do receptor Toll-like 2 na defesa do hospedeiro contra o fungo Sporothrix schenckii. 2012. 116 f. Tese (doutorado) - Universidade Estadual Paulista, Faculdade de Ciências Farmacêuticas, 2012.