Cytolethal distending toxin B from Actinobacillus actinomycetemcomitans induces cell death.

Abstract

The CDTS constitute a family of heat-labile toxins produced by several bacterial species. CDT is encoded by three genes, cdtA, cdtB and cdtC, and their products, CdtA, CdtB and CdtC, are responsible for the toxic activity. In this study, to investigate cytotoxic activity of CdtB, we tried to deliver CdtB protein alone into cancer cell. CdtB gene from A.actljlonlyceteJ12comjtans was transformed into E.colj to induce the recombinant protein. CdtB protein extracted from E.colj transformant was delivered into Ca9-22 cells, human gingival squamous cell carcinoma, using BioPORTERTM, and cytotoxic activity was assessed by MTT assay, flow cytometry and hoechst staining. We found that CdtB itself could induce G2 cell cycle arrest and apoptosis.