Excreted/Secreted Proteins from Trypanosome Procyclic Strains

Abstract

Trypanosomasecretome was shown to be involved in parasite virulence and is suspected of interfering in parasite life-cycle steps such as establishment in theGlossinamidgut, metacyclogenesis. Therefore, we attempted to identify the proteins secreted by procyclic strains ofT. brucei gambienseandT. brucei brucei, responsible for human and animal trypanosomiasis, respectively. Using mass spectrometry, 427 and 483 nonredundant proteins were characterized inT. brucei bruceiandT. brucei gambiensesecretomes, respectively; 35% and 42% of the corresponding secretome proteins were specifically secreted byT. brucei bruceiandT. brucei gambiense, respectively, while 279 proteins were common to both subspecies. The proteins were assigned to 12 functional classes. Special attention was paid to the most abundant proteases (14 families) because of their potential implication in the infection process and nutrient supply. The presence of proteins usually secreted via an exosome pathway suggests that this type of process is involved in trypanosome ESP secretion. The overall results provide leads for further research to develop novel tools for blocking trypanosome transmission.