Figure 2

T. spiralis IIL invasion and migration in a Caco-2 cell monolayer. After a Caco-2 cell monolayer was covered with semisolid MEM containing IIL and cultured at 37 °C for 2 h, IIL invasion and migration were examined by microscopy. A Non-invaded larvae were coiled on the surface of the Caco-2 cell monolayer. B, C Invaded larvae left a migratory path in the monolayer. D The nuclei of dead cells were dyed orange with PI, IIL ESPs were recognized with anti-ESP immune serum, and green fluorescence in the cytoplasm of damaged cells was observed by fluorescence microscopy. E The nuclei of damaged cells were stained intensely and uniformly orange by PI, showing the serpentine trail left by the parasite. F The IIL ESPs within the migratory path were detected using anti-ESP immune serum. Scale bars: 20 μm.