Characterization of components secreted by Trypanosoma cruzi extracellular amastigotes and their effect on cell invasion

Abstract

Infection by Trypanosoma cruzi, the etiological agent of Chagas disease remains a major public health problem in Latin America, home of most people infected. In nonendemic regions like/such as the US, Europe, Japan, and Australia there is growing concern about the risks of transmission by blood transfusion (and organ transplant). Considering that T. cruzi taxon comprises genetically distinct populations with important genotypic and phenotypic characteristics and distinct infectivity patterns, we are faced with a major challenge of understanding the molecular basis of these (genetic and epigenetic) variabilities. We propose to investigate chromosomic polymorphisms and ploidy variations among different T. cruzi strains that could be part of the resources used by the parasite to cope with environmental stress. We will examine the effects of ionizing radiation on chromosome organization of the parasite, as well as the generation of recombinant events capable of changing karyotype and ploidy, which may contribute to the genetic diversity of T. cruzi. Karyotype and genome comparisons of different species of the Schyzotrypanum clade (T. cruzi e T. cruzi-like) that includes nonpathogenic trypanosomes from South America will provide insights into chromosome evolution. Different strategies and methodologies will be used, including the novel genomic editing with CRISP-Cas9, aiming at clarifying the mechanisms underlying cell invasion by metacyclic trypomastigotes and extracellular amastigotes, infective forms of T. cruzi that differ in the repertoire of interacting molecules. We will also investigate the role of cytoskeletal elements of the target cell as well as putative receptors for T. cruzi surface molecules and microvesicles released by the parasite, components of growing importance evidenced by studies with tissue culture trypomastigotes. Coinfections with different strains to elucidate mechanisms of intracellular growth and egress from parasitized mammalian cells will also be our object of study. Researchers who have been collaborating in a highly productive manner for several years with wide experience in Protozoology, with special focus on Molecular and Cellular Biology will carry out this multidisciplinary project. With the aid of researchers in Brazil and abroad, we aim to expand the knowledge on the topics proposed herein. (AU)