Estudio del proteoma de las líneas celulares de alta virulencia (C8C3hvir) y de baja virulencia (C8C3lvir) del clon H510 C8C3 de Trypanosoma cruzi

Abstract

Trypanosoma cruzi is the etiological agent of Chagas disease, which in its chronic forms is characterized by cardiac and digestive involvement. Considering that the molecular repertoire of the parasite modulates its virulence and has an impact on the clinical course of Chagas disease, this study aims to determine the mechanism underlying the pathogenicity of T. cruzi. Two T. cruzi cell lines, high virulence C8C3hvir and low virulence C8C3lvir, obtained from clone H510 C8C3, were used to infect mice. The infectivity of the cell lines was assessed by performing parasitemia curves. The proteomes of both T. cruzi cell lines were compared by nLC-MS/MS. The expression levels of cruzipain (Czp), complement regulatory protein (CRP), transialidases (TS), Tc85 and sialylated epitopes in cell culture-derived trypomastigotes of C8C3hvir and C8C3lvir were evaluated by immunoblotting. The highly virulent C8C3hvir cell line was highly infective to mice, even inhibiting virulence factors such as Czp, TS and CRP. A total of 1547 proteins were identified by comparative quantitative proteomics, being, 387 differentially regulated in C8C3hvir with respect to C8C3lvir. Among them, 174 and 216 were up- and down-regulated in C8C3hvir and C8C3lvir, respectively. The C8C3hvir cell line showed up-regulation of tricarboxylic acid (TCA) cycle enzymes, ribosomal proteins and redoxins. Immunoblots showed that C8C3hvir expressed higher levels of Czp, CRP, TS, Tc85 and sialylated epitopes than C8C3lvir. C8C3hvir not only differentially expressed some virulence factors relative to C8C3lvir, but also exhibited up-regulated metabolic pathways. Therefore, it appears that T. cruzi virulence is not only related to the expression of virulence factors (such as Czp, CRP, TS) but also to the regulation of bioenergetic and biosynthetic pathways.