Interaction of T. cruzi trypomastigotes with host cells before invasion causes mechanical deformations on the plasma membrane. (A) Time-lapse phase-contrast live images of trypomastigotes interacting with a HeLa cell (Video 2). The gliding movement of attached trypomastigotes (arrow) cause reversible plasma membrane deformations (arrowhead). Bars, 10 µm. (B and C) Scanning electron microscopy images of trypomastigotes during early stages (10 min) of interaction with host cells. Trypomastigotes are observed gliding under cells (B) or in close contact with the plasma membrane at the cell periphery (C). Bars, 5 µm. These results are representative of two independent experiments.