RAB 32 IS PRESENT IN THE Trypanosoma cruzi PARASITOPHOROUS VACUOLE AND CONTRIBUTES TO THE INFECTION PROCESS.

SALASSA BN; ROMANO PS; CUETO JA

Buenos Aires

Congreso; Reunión Conjunta de Sociedades de Biociencias; 2017

Sociedades Científicas (SAIC, SAIB, SAP, etc)

Trypanosoma cruzi, the etiological agent of Chagas´ disease is a protozoan parasite which infects both phagocytic and non-phagocytic mammalian cells. At early stages of infection trypomastigotes localizes in a vesicular compartment called the T. cruzi parasitophorous vacuole (TcPV) until the escape to cell cytoplasm to continue their cycle. Rab and SNAREs proteins are involved in the molecular machinery of membrane traffic. Rab GTPases have emerged as central regulators of vesicle recognition and transport, whereas SNAREs are mainly involved in the fusion process between membranes. In a previous research, we characterized that the T. cruzi infection process in non-phagocytic cells occurs in two stages, the formation and maturation of the TcPV. We also showed that the v-SNARE VAMP7 is required for the TcPV development and for the establishment of infection. The aim of this work was to identify other molecular components of the vesicular transport pathways and their participation in the T. cruzi infection. CHO cells were transfected to overexpress GFP-Rab proteins from the endocytic and exocytic pathways and then infected with trypomastigotes for 1 h. After this time, cells were fixed and processed to detect the parasites by indirect immunofluorescence. Similar procedures were performed in CHO cells overexpressing GFP alone as control. By confocal microscopy we observed that Rab32 was recruited to the membrane of the TcPV. Frequency of this localization was higher (43 +/- 0.3 %) and similar to the observed for VAMP7 at the same time. In addition we found that the presence of high levels of Rab32 significantly increased T. cruzi infection. Due to Rab32 effectors can regulate binding of VAMP7 and therefore the fusion events triggered by them, these results open a novel way to understand the mechanisms that control the formation and maturation of the T. cruzi vacuole.