Mucin-like glycoproteins of Trypanosoma cruzi metacyclic forms: interaction with other surface molecules of the parasite and with the host cell

Abstract

Metacyclic trypomastigote forms of Trypanosoma cruzi express surface glycoproteins that interact with the host cell, promoting or negatively modulating their internalization. The mechanisms of invasion by metacyclic forms involving two of these molecules, gp82 and gp90, were partially elucidated. As regards the mucin-like glycoproteins, gp35/50, there is less information. Ggp82 and gp90 bind to the host cell and induce opposite effects on the mobilization of lysosomes, organelles that play an important role in the internalization of metacyclic forms. What is the effect of gp35/50 on the lysosome distribution is still to be investigated. Another aspect to be examined refers to the eventual association between different metacyclic form surface molecules. Could gp35/50 associate with gp90 or g82, exerting a modulatory role, interfering with the host cell interaction? In an attempt to clarify the referred questions, human epithelial cells and T. cruzi G and CL strains, which differ in their invasion capacity, will be used. We intend to: i) Determine the effect of purified gp35/50 on the host cell invasion by metacyclic forms, ii) Examine whether purified gp35/50 is able to affect the gp82 activity in inducing lysosome spreading, iii) Analize whether there is association of gp35/50 expressed in metacyclic forms with gp82 or gp90, and if this is the case whether the association occurs in both strains, iv) Determine whether gp35/50 bind to the recombinant gp82 or gp90 containing the host cell binding site. (AU)