Concanavalina-A aumenta a produção de TNF-a, a atividade de receptores de manose e a capacidade de destruir Candida por macrófagos peritoneais

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

22/02/2010

RESUMO

Recognition of Candida albicans by Toll-like receptors and lectin receptors on the phagocytic cells activates intracellular signaling pathways that trigger production of proinflammatory cytokines that are critical for host defence. Th1-response provide control of fungal infectivity by increasing the expression of receptors that acts as sensors for infection inducing the activation of the innate immune responses as well as the subsequent development of adaptive immune responses. In previous work, our group demonstrated the protective role of concanavalin-A (Con-A) for a lethal inoculum of C. albicans and indicated the macrophages as main effectors cells to clear the pathogen. The main objective of this study was to investigate the activity of mannose receptors and tumor necrose factor-alpha (TNF–α) production, as well as, the increase in capacity to kill the pathogen by activated macrophages from mice pretreated with Con-A. Thus, peritoneal macrophages from mice pretreated for three days with Con-A or PBS were coincubated with CR1, CR15 and 577 isolates of C. albicans for 0.5, 1 and 2 h. The ability of Con-Activated macrophages to produce TNF-α, ingest via mannose receptors and kill all the isolates was significantly greater compared to PBS-treated macrophages and activated macrophages exhibited a lower incidence of apoptosis, verified by binding to annexin V-FITC. The transition of yeast cells to filamentous forms during coincubation for 2h with control macrophages was about 73 to 80%, whereas in presence of Con-A-activated macrophages, it was 35 to 40%. Taken together, our results suggest that a greater clearance of C. albicans infection through treatment with Con-A is probably due to activation of macrophages, which produce more TNF-α, expresses more mannose receptors and are better endowed to kill ingested C. albicans.

ASSUNTO(S)

candida albicans candida albicans - patogenicidade fungos patogênicos macrófagos candidiasis fungi pathogenic

ACESSO AO ARTIGO

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