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

PLoS Negl Trop Dis. 2017 Jun 6;11(6):e0005657. doi: 10.1371/journal.pntd.0005657. eCollection 2017 Jun.

Abstract

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.

MeSH terms

  • Animals
  • Caveolin 1 / genetics
  • Caveolin 1 / metabolism
  • Cell Membrane / physiology*
  • Endocytosis
  • Fibroblasts / metabolism
  • Fibroblasts / parasitology*
  • Fibroblasts / ultrastructure
  • Gene Expression Regulation / physiology
  • Lysosomal Membrane Proteins / genetics
  • Lysosomal Membrane Proteins / metabolism*
  • Lysosomal-Associated Membrane Protein 2 / genetics
  • Lysosomal-Associated Membrane Protein 2 / metabolism*
  • Mice, Knockout
  • Trypanosoma cruzi / physiology*

Substances

  • Caveolin 1
  • Lamp1 protein, mouse
  • Lysosomal-Associated Membrane Protein 2
  • Lysosomal Membrane Proteins

Grants and funding

This work has been funded by Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG- APQ-02269-14) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq- 479623/2009-0, INCT/CNPq Proc. 465259/2014-6). I would like to add that the funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.