Studies of host-pathogen interaction of Histoplasma capsulatum biofilms mediated by Hsp60-CR3 in a functional human lung tissue model

Abstract

Histoplasmosis is a pulmonary and systemic fungal infection caused by the thermodimorphic fungus Histoplasma capsulatum that affects thousands of people annually. The World Health Organization recently ranked it as a high priority among human fungal pathogens. Several mechanisms are related to the process of establishment and development of the infection, among the important factors for the pathogenesis of the disease, cellular adhesion mediated with Hsp60/CR3 and probably the formation of biofilms stand out. Biofilms are sessile communities of microorganisms where cells are adhered to an interface or substrate surrounded by an extracellular matrix (ECM) composed of several polymeric substances that contribute to their virulence. Previous research from our group using omics approaches identified the differential expression of metabolites, RNAs and proteins from the comparative analysis of planktonic yeasts and in H. capsulatum biofilms from the metabolome, transcriptome and proteome. The transcriptome analysis of the infection also revealed the presence of differential expression of miRNAs when the cell is infected by biofilms, raising different questions related to the pathogen-host interaction of H. capsulatum. The hypothesis is that the pathogen-host interaction of biofilms occurs differentially in H. capsulatum yeasts, with biofilms capable of simultaneously activating different interaction pathways while promoting rapid phagocytosis, not having the Hsp-60/CR3 pathway as the main one, as demonstrated in yeasts. Thus, the objective of this project is to study the influence of the Hsp60 protein in H. capsulatum biofilms, and its role during the biofilm-host interaction in a three-dimensional model of human lung tissue, characterizing the interaction mediated by this protein in the infective process, the from the blockade of Hsp60 with monoclonal antibody mAb (76B) followed by infection of three-dimensional human lung tissue in vitro and evaluation of the expression of genes differentially expressed by fungal biofilms and host genes important in the pathogen-host interaction by RT-qPCR.