In vitro challenge of human dendritic cells with Paracoccidioides brasiliensis induces preferential generation of Treg cells

Paracoccidioidomycosis (PCM) is a systemic mycosis, endemic to most Latin American countries (especially Brazil) whose etiologic agent is the thermodimorphic fungus Paracoccidioides brasiliensis (Pb). Host resistance/susceptibility to PCM has been explained by the involvement of different subpopulations of CD4⁺ cells. However, the mechanisms leading to preferential induction of any subpopulation are still unclear, and the participation of dendritic cells (DCs) must be highlighted. These cells bind, capture, kill, process microorganisms and migrate to peripheral lymphoid tissue where they maturate, efficiently trigger, and drive CD4⁺ T cell-mediated immune responses. The nature of the interaction of these cells with each microorganism defines CD4⁺ cell differentiation. Few studies have evaluated which subsets of CD4+ cells are preferentially induced after the interaction of human DCs/Pb. Here, we show that in vitro challenge of DCs with Pb results in the preferential induction of T_reg cells.