FIG 3.

Clathrin-mediated endocytosis is required for intracellular S. pneumoniae-mediated killing. Shown is the interaction between HL-1 cardiomyocytes and TIGR4 in the presence of the designated endocytosis inhibitors. (A) Adhesion was measured 30 min after infection and invasion was measured 1 h after infection followed by 1 h of gentamicin treatment. (B) TIGR4-mediated HL-1 cell death in the presence of designated endocytosis inhibitors was measured using LDH release (n = 3). Errors bars represent standard errors of the means. Statistical analyses were done with t test (methyl-beta-cyclo-dextrin [MβCD] and PitStop 2) and 1-way ANOVA with Holm-Sidak correction for multiple comparison (cytochalasin D and genistein) (A) and t test (B). ***, P ≤ 0.001; ****, P ≤ 0.0001. Endocytosis inhibitors were used at the following concentrations: MβCD, 10 mM; cytochalasin D, 10 μM; genistein, 200 μM; and PitStop 2, 30 μM.