Lysosome biogenesis/scattering increases host cell susceptibility to invasion by Trypanosoma cruzi metacyclic forms and resistance to tissue culture trypomastigotes

Abstract

SummaryA fundamental question to be clarified concerning the host cell invasion by Trypanosoma cruzi is whether the insect‐borne and mammalian‐stage parasites use similar mechanisms for invasion. To address that question, we analysed the cell invasion capacity of metacyclic trypomastigotes (MT) and tissue culture trypomastigotes (TCT) under diverse conditions. Incubation of parasites for 1 h with HeLa cells in nutrient‐deprived medium, a condition that triggered lysosome biogenesis and scattering, increased MT invasion and reduced TCT entry into cells. Sucrose‐induced lysosome biogenesis increased HeLa cell susceptibility to MT and resistance to TCT. Treatment of cells with rapamycin, which inhibits mammalian target of rapamycin (mTOR), induced perinuclear lysosome accumulation and reduced MT invasion while augmenting TCT invasion. Metacylic trypomastigotes, but not TCT, induced mTOR dephosphorylation and the nuclear translocation of transcription factor EB (TFEB), a mTOR‐associated lysosome biogenesis regulator. Lysosome biogenesis/scattering was stimulated upon HeLa cell interaction with MT but not with TCT. Recently, internalized MT, but not TCT, were surrounded by colocalized lysosome marker LAMP2 and mTOR. The recombinant gp82 protein, the MT‐specific surface molecule that mediates invasion, induced mTOR dephosphorylation, nuclear TFEB translocation and lysosome biogenesis/scattering. Taken together, our data clearly indicate that MT invasion is mainly lysosome‐dependent, whereas TCT entry is predominantly lysosome‐independent.

SolubleN-ethylmaleimide-sensitive factor attachment protein receptors required duringTrypanosoma cruziparasitophorous vacuole development

“…VAMP7 KO MEF and WT MEF cells were infected for 3 hr with Try and then subjected to a double IF to detect intracellular parasites and LAMP1. Figure 6a (upper panel) shows LAMP1 puncta outlining internalized parasites in WT MEF cells, corroborating previous reports (Caler, Chakrabarti, Fowler, Rao, & Andrews, 2001;Fernandes et al, 2011;Zhao et al, 2013;Cortez et al, 2015). However, in VAMP7 KO MEF cells, LAMP1 labeling was less evident in the TcPV membrane (Figure 6a , lower panel).…”

“…As expected, the timing of LAMP1 acquisition mainly paralleled that observed for VAMP7. This low recruitment of LAMP1 at the site of Try entry should be reinterpreted in the light of results published by Cortez, Real, and Yoshida (2015). They proved that metacyclic Try generated in vitro (equivalent of insect-borne parasite form) need lysosomal exocytosis to get inside cells, whereas tissue culture-derived Try (equivalent of bloodstream parasite form), the same parasite form used in this work, did not require lysosomes for invasion, although later they resulted absolutely necessary to establish an effective internalization.…”

Plasmodium secretion induces hepatocyte lysosome exocytosis and promotes parasite entry

“…To assess the quantity and localization of lysosomes within infected and uninfected cells we defined LE/lysosomes as LAMP1-positive structures between 0.25 to 1 µm in diameter, corresponding to the typical size of LE/lysosomes within the mammalian cell. Hepa1-6 cells contained an average of ~450 LAMP1-positive structures, similar to measurements obtained by other groups( 10 ). We defined perinuclear lysosomes as LAMP1-positive structures that were within a region surrounding the nucleus that was delineated by extrapolating the DAPI signal.…”

Frontline Science: Autophagy is a cell autonomous effector mechanism mediated by NLRP3 to control Trypanosoma cruzi infection

“…These large compartments are likely not a consequence of the lysosomes recruitment during T. cruzi cell invasion, since they are distinct from the small Lysotracker ‐ or LAMP‐1‐positive dots found throughout cell cytosol until 60 min after infection. Moreover, recent data indicate that, distinct from metacyclic trypomastigotes (MT), TCT invasion occurs in a lysosome‐independent manner . In addition, the acidic vesicles which contain the parasites after 1–2 h of infection were located in the perinuclear region of the cell and not at plasma cell membrane, suggesting that large vesicles are assembled in the cell cytosol.…”