Ifluences of TLR3 in experimental PCM model

Abstract

Paracoccidioidomycosis (PCM) is a deep mycosis caused by species of the genus Paracoccidioides, which induce a systemic granulomatous disease, that preferentially affects the lung tissue. Paracoccidioides brasiliensis (P. brasileinsis) and Paracoccidioides lutzii (P. lutzii) are a dimorphic fungi and through conidia and hyphal fragments begins the infection process. At the beginning of this process, antigen-presenting cells (APCs) such as dendritic cells (DCs) and their receptors are important in determining the induced immune response. DCs, antigen-presenting considered "professional" cells, which are responsible for the capture, processing, migration and antigen presentation can modulate the immune response through the interaction of the fungi and / or their antigens with Toll-like receptors (TLRs ), leading to the regulation of costimulatory molecules and cytokine production. Studies suggest the involvement of TLRs in the recognition of several fungi, such as Candida albicans, Aspergillus fumigatus or Cryptococcus neoformans. It was demonstrated the role of TLR3 in the experimental aspergillosis, which served as an endogenous sensor yeast RNA contributing to the regulation of local inflammation and activation of memory and protective response mediated by CD8 + T cells from TLR3 signaling in DCs pulsed with conidia of the fungus or RNA. Knowing that TLR3 signaling pathway has been shown to be important in models of fungal infections, this work aims to study and evaluate the participation of these receptors in modulating the immune response in experimental PCM. (AU)