Paracoccin impacts on Paracoccidioides brasiliensis virulence and susceptibility to antifungal drugs by modifying the expression of genes related to remodeling of the yeasts cell wall

Abstract

The study of the paracoccin lectin (PCN) has provided knowledge about its role in the biology of Paracoccidioides brasiliensis and in the pathogenesis of paracoccidioidomycosis (PCM). In this context, PCN has proved to be a promising immunomodulatory agent for the exploration of vaccine target molecules and/or for diagnostic or therapeutic purposes. Previous investigations allowed establishing PCN as a factor of fungal virulence. However, the effect PCN exerts on the yeasts resistance to antifungal pharmacological agents used to treat human PCM are not known. Therefore, this work characterizes the role of PCN functional duality on virulence and susceptibility of P. brasiliensis to antifungal drugs. We show that the PCN overexpression increases the virulence of P. brasiliensis yeasts in an alternative model of infection, induces high susceptibility in vitro and in vivo of P. brasiliensis yeasts to antifungal therapy, and impact reducing relative mRNA expression of genes encoding proteins related to cell wall degradation. Conversely, PCN silencing minimized the yeasts virulence in Galleria mellonella, correlates with the lowest susceptibility to treatment with antifungal agent in vivo and impact differently from the PCN overexpression on the relative expression of markers related to P. brasiliensis yeasts cell wall remodelling. Our study demonstrates the impact of endogenous PCN on the P. brasiliensis yeasts virulence vs. susceptibility to antifungal drugs, the fungal biology, and the relationship of the yeasts-host cells.