Correction: LAMP-2 absence interferes with plasma membrane repair and decreases T. cruzi host cell invasion

Trypanosoma cruzi enters host cells by subverting the mechanism of cell membrane repair. In this process, the parasite induces small injuries in the host cell membrane leading to calcium entry and lysosomal exocytosis, which are followed by compensatory endocytosis events that drive parasites into host cells. We have previously shown that absence of both LAMP-1 and 2, major components of lysosomal membranes, decreases invasion of T. cruzi into host cells, but the mechanism by which they interfere with parasite invasion has not been described. Here we investigated the role of these proteins in parasitophorous vacuole morphology, host cell lysosomal exocytosis, and membrane repair ability. First, we showed that cells lacking only LAMP-2 present the same invasion phenotype as LAMP1/2-/- cells, indicating that LAMP-2 is an important player during T. cruzi invasion process. Second, neither vacuole morphology nor lysosomal exocytosis was altered in LAMP-2 lacking cells (LAMP2-/- and LAMP1/2-/- cells). We then investigated the ability of LAMP-2 deficient cells to perform compensatory endocytosis upon lysosomal secretion, the mechanism by which cells repair their membrane and T. cruzi ultimately enters cells. We observed that these cells perform less endocytosis upon injury when compared to WT cells. This was a consequence of impaired cholesterol traffic in cells lacking LAMP-2 and its influence in the distribution of caveolin-1 at the cell plasma membrane, which is crucial for plasma membrane repair. The results presented here show the major role of LAMP-2 in caveolin traffic and membrane repair and consequently in T. cruzi invasion.
Author summary Trypanosoma cruzi is the etiological agent of Chagas disease, a very debilitating illness that has no efficient treatment to date. Better knowledge of the mechanisms involved with host cell infection is important to change this scenario. T. cruzi enters host cells by subverting the mechanism by which cells repair small injuries in their plasma membrane. In this process, parasites interact with host cells causing membrane injuries. These injuries lead to secretion of lysosomal content to the extracellular media, which in turn causes the internalization of plasma membrane wounds via endocytosis. During this endocytic process the parasite is internalized by the host cell. We have previously shown that absence of two proteins located at the lysosomal membrane, LAMP-1 and 2, severely interferes with T. cruzi entry into host cells. In the present manuscript we show that absence of LAMP-2 alone is enough to compromise T. cruzi entry into host cells and it does so by compromising the endocytic events that follow lysosome secretion, which in turn is responsible for driving T. cruzi into the host cell interior.