Trypanosoma cruzi emplys the SNARE Vamp 7 to invade host cells

ARBOIT MA, COLOMBO MI, ROMANO PS

Tucuman

Congreso; Reunión Científica Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología molecular (SAIB); 2009

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB)

The etiologic agent of Chagas disease, Trypanosoma cruzi, infects a wide variety of mammalian cells. Previous works have demonstrated that the recruitment of acidic compartments to the plasma membrane is necessary to allow the invasion of the parasite into the host cell. In order to study the machinery of fusion involved in this invasion process, we have used CHO cells overexpressing NSF-wt-GFP and NSF-D1EQ-GFP (negative mutant: NM) and we have observed, by confocal microscopy, an increase of infection in NSF-wt cells; whereas there is a significant lower level of infection in the NM cells. We have also studied the role of VAMP 7, a v-SNARE protein. CHO cells overexpressing VAMP 7-wt-GFP showed a high level of association between this protein and the T. cruzi parasitophorous vacuole (TcPV). Besides, the non-functional protein VAMP 7-NT-GFP does not colocalize with the TcPV and decreases the number of parasites which invade the cell. We have also analyzed the relationship between the autophagic pathway and VAMP 7. In this case, we have observed that cells overexpressing both, LC3-RFP and VAMP 7-GFP proteins, present a higher percentage of infection than the control cells, even under starvation condition. These results show that the invasion of T. cruzi is a NSF dependent fusion process, where VAMP 7 plays a key role in both the lysosomal and the autophagic models of T. cruzi entry.