Clostridial Glucosylating Toxins Enter Cells via Clathrin-Mediated Endocytosis
Figure 2
Pharmacological inhibition of clathrin assembly with chlorpromazine.
HeLa cells were preincubated with chlorpromazine (Cp) or left untreated, prior to addition of (A) 5 nM diphtheria toxin (DT) and incubation for 180 min, (B) 3.5 nM CNF1 and incubation for 150 min or (C) 4 pM toxin B and incubation for 75 min. (D) The percentage of cell rounding in chlorpromazine-pretreated or non-pretreated HeLa cells after intoxication with 4 pM toxin B for 75 min, 1.5 nM toxin A for 105 min, 4 nM lethal toxin for 75 min or 1.5 nM α-toxin for 60 min was quantified and data are given +/− SD (n = 3) and from a minimum of 200 cells in total. (E) Human intestinal epithelial cells (CaCo-2) were grown to confluency on filters and were preincubated with chlorpromazine (Cp) or left untreated. A subset of cells was intoxicated with 40 pM toxin B and transepithelial electrical resistance (TER) was measured at indicated time points, where starting resistance was set to 100% and TER values are calculated as relative TER in % from starting resistance (+/− SD, n = 3).