Characterization of human colonic epithelial cells <i>in vitro</i> infection by <i>T</i>. <i>cruzi</i> Tulahuen trypomastigotes (MMC 20A).

Primary HCoEpiC cells were infected with transgenic T. cruzi trypomastigotes, Tulahuen strain (MMC20A) expressing GFP to reveal the infectivity profile. HCoEpiC were grown in Lab-Tek chamber slides (~80% confluence), starved in CoEpiCM without supplements and challenged with transgenic T. cruzi trypomastigotes during 0, 60, 90, 120, and 180 minutes. Parasites were washed off and the slides were fixed to evaluate internalized parasites. For regular infection, incomplete CoEpiCM was replaced with complete medium containing supplements and slides incubated in tissue culture incubator. The complete media was changed daily until 72 hours post infection. The slides were washed, fixed, stained with phalloidin and DAPI before being subjected to confocal microscopy analysis where average cellular infections were evaluated in several fields. (A) The percentage of infected colonic epithelial cells at 0, 60, 90, 120, and 180 minutes (B) Chart showing the number of intracellular parasites per cell (mean ± SE) 0, 60, 90, 120, and 180 minutes of infection (C) The percentage of infected colonic epithelial cells at 72 h of regular infection (D) Microscopic images of control and T cruzi trypomastigotes infected HCoEpiC at 180 min and 72h.