XI International Meeting on Paracoccidioidomycosis

XI International Meeting on Paracoccidioidomycosis

Resume:132-1

Poster (Painel)

132-1	Mannose receptors play a dual role in the activation of macrophages from resistant and susceptible mice to Paracoccidioides brasiliensis infection
Authors:	Claudia Feriotti (USP - Universidade de Sao Paulo) ; Vera Lucia Garcia Calich (USP - Universidade de Sao Paulo)

Abstract

INTRODUCTION: The mannose receptor (MR) is a member of C-type lectin family of receptors which binds predominantly to mannosyl residues on the outer layer of the cell wall of several fungi including P. brasiliensis (Pb). The mechanisms which govern this interaction, however, are still poorly understood. OBJECTIVES: The aim of our work was to characterize the role of MRs in the interaction between P. brasiliensis yeast cells and macrophages from susceptible (B10.A) and resistant (A/J) mice. METHODOLOGY: Thyoglicolate-induced peritoneal macrophages from B10.A and A/J mice were activated or not by IFN-γ. Some macrophages cultures were treated with mannan from Saccharomyces cerevisiae before and during challenge with Pb yeasts. Supernatants were collected to characterize NO and cytokines production. Cells were disrupted and plated to determine fungicidal activity. RESULTS: The presence of mannan during infection of A/J and B10.A macrophages resulted in increased fungicidal activity and NO production. Compared with cells from B10.A mice, A/J macrophages showed higher expression of costimulatory molecules CD40, CD86, DC-SIGN, TLR2 and Dectin-1 receptors, but lower phagocytic ability. Mannan treatment modulated the expression of costimulatory molecules of both mouse strains but exerted an inhibitory effect in the phagocytic activity of B10.A macrophages. Mannan-treated macrophages from B10.A mice produced elevated levels IL-12 but diminished levels of IL-10, TNF-α and IL-6. On the contrary, manan-treated A/J macrophages produced increased levels of IL-6, TNF-α and IL-10, but decreased levels of IL-12. CONCLUSION: This work demonstrates that mannan is able to activate A/J and B10.A macrophages, inducing, however, a different profile of cell activation. Financial support by FAPESP

Keyword: Mannose receptor, Paracoccidioides brasiliensis, innate immunity, mannan

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