The Apoptosis Induction of CT 26 Cells by Recombinant Clostridium difficile Toxin B / 微生物学通报

ABSTRACT

To investigate the induction of apoptosis of mouse colonic adenocarcinoma CT26 cells by recombinant Clostridium difficile toxin B (rTcdB), CT26 cells were exposed to different concentrations of rTcd B. Inhibition of cell proliferation was measured by MTT assay. The activation of Caspase 3 was measured by colorimetric method. Cell morphological analysis and flow cytometry were performed to confirm cell apoptosis. rTcd B inhibited the proliferation of CT26 cells in a timeand dose-dependent manner. Caspase 3 activity in CT26 cells was elevated remarkably after rTcd B exposure for 6 h, 12 h, 18 h or 24 h, as compared with the control group. Morphological changes were observed by fluorescence microscopy. The exposure of rTcd B to CT26 cells induced a timeand dose-dependent apoptotic cell death as determined by flow cytometry analysis. The results showed that recombinant Clostridium difficile toxin B induced apoptosis of CT26 cells.