The trans-sialidase, the major Trypanosoma cruzi virulence factor: Three decades of studies.

Chagas' disease is a potentially life-threatening disease caused by the protozoan parasite Trypanosoma cruzi. Since the description of Chagas'disease in 1909 extensive research has identified important events in the disease in order to understand the biochemical mechanism that modulates T. cruzi-host cell interactions and the ability of the parasite to ensure its survival in the infected host. Exactly 30 years ago, we presented evidence for the first time of a trans-sialidase activity in T. cruzi (T. cruzi-TS). This enzyme transfers sialic acid from the host glycoconjugates to the terminal β-galactopyranosyl residues of mucin-like molecules on the parasite's cell surface. Thenceforth, many articles have provided convincing data showing that T. cruzi-TS is able to govern relevant mechanisms involved in the parasite's survival in the mammalian host, such as invasion, escape from the phagolysosomal vacuole, differentiation, down-modulation of host immune responses, among others. The aim of this review is to cover the history of the discovery of T. cruzi-TS, as well as some well-documented biological effects encompassed by this parasite's virulence factor, an enzyme with potential attributes to become a drug target against Chagas disease.