Phospholipase A1fromTrypanosoma cruziinfective stages generates lipid messengers that activate host cell protein kinase c

Abstract

Here we have studied phospholipase A1(Plase A1) fromTrypanosoma cruziinfective stages and it's possible role regarding the interaction with mammalian host cells. Plase A1was mainly detected as a membrane-bound activity in the infective amastigote and trypomastigote stages, being remarkably higher with respect to the non-infective epimastigotes. It is noteworthy that only the infective stages secreted Plase A1. Moreover, along the differentiation process from epimastigotes into metacyclic trypomastigotes, the secreted enzyme activity increased simultaneously with the appearance of metacyclic forms, as expected. Since this enzyme is predominantly membrane-associated and secreted by the infective stages, Vero cell lipid profile modifications were analysed after interaction with either intact infective parasites or purifiedT. cruziPlase A1. Significant changes in Vero cell lipid composition were observed, with the appearance of free fatty acids, diacylglycerol and lysophosphatidylcholine. Concomitantly with the generation of second lipid messengers, host cell protein kinase C activation was demonstrated. These results indicate thatT. cruziPlase A1could play a critical role in the early events of parasite-host cell interaction that precede invasion.