Trypanosoma cruzi Journey from the Insect Vector to the Host Cell

Abstract

Trypanosoma cruzi, etiological agent of Chagas disease, has evolved a complex interaction with mammalian cells and insect vector’s intestine. During its journey between these environments, it is subject to stressful changes. To overcome them, parasites use numerous strategies. Different stages contact diverse compartments of hosts and vectors thus assuring survival and multiplication. Surface proteins, some identified in particular stages of the protozoan, are critical for interaction with the milieu although their relevance is not totally understood for many. Parasite molecules allow T. cruzi to progress in the vector intestine, to duplicate and differentiate in order to become the infective stage for mammals. Surface molecules also allow parasites to advance through intracellular matrix of the mammals to reach the cells and, after recognition, invade them and adapt to survive but also to multiply and differentiate to circulating trypomastigotes thus assuring life cycle continuity. In this chapter we summarize T. cruzi pathways of humans and other reservoirs of infection as well as the participation of different T. cruzi lineages in geographical distribution and human disease. Finally, we review some of the mechanisms used by the parasite to reach, enter, and survive inside the host cell described so far.