Phospholipase A1 distribution changes dramatically throughout Trypanosoma cruzi life cycle

BELAUNZARÁN M.L.,; WAINSZELBAUM M.J.,; LAMMEL E.M., GIMENEZ G.,; GENTILI H.,; FLORIN-CHRISTENSEN J.,; ISOLA E.L.D.

Brighton, UK

Congreso; 6th Congreso of the Internacional Society for the Study of Fatty Acids and Lipids.; 2004

Internacional Society for the Study of Fatty Acids and Lipids.

We here report that Phospholipase A1 specific activity in amastigotes is 15-fold higher than in epimastigotes and resides mainly on its membrane fraction. Furthermore, only the infective amastigotes and trypomastigotes secrete the activity to the medium. In agreement with these observations, we demonstrate that, during metacyclogenesis, the secreted activity increases, reaching a peak at aproximately day 8 of the differentiation process, at which time, the proportion trypomastigotes to epimastigotes is maximal. We suggest that membrane associated and secreted Phospholipase A1, are new markers for differentiation of T. cruzi. Our findings may have important biological consecuences. When [14C-1]-oleic acid labeled Vero cells are incubated for short periods (15min) with amastigotes, their lipids changes dramatically, with the appearance of free fatty acids, diacylglycerol and lysophosphatidylcholine. This indicates strong effects on membrane lipid composition in target host cells. Since diacylglycerol is increased, we investigated the possible activation of PKC in the host cells. We found that, indeed, this enzyme is clearly stimulated under the experimental conditions employed.