BACKGROUND & OBJECTIVE: Campylobacter jejuni is the leading cause of gastroenteritis worldwide; cytolethal distending toxin (CDT) being an important virulence determinant. As its role in pathogenesis remains unclear, this study aims to investigate cell cycle arrest and apoptosis by CDT (+ve) and CDT (-ve) C. jejuni isolates on HeLa cells. METHODS: Culture supernatants and lysates from 10 C. jejuni isolates [CDT (+ve) and CDT (-ve), five each] were incubated with HeLa cells. CDT activity on HeLa cells was confirmed by cell distension, cell cycle arrest by flowcytometry, and apoptosis by DNA fragmentation and flowcytometry. RESULTS: Culture supernatant and lysate of only CDT (+ve) C. jejuni isolates produced cell distension. For CDT (+ve) and CDT (-ve) isolates, the cells at G2/M phase after 24, 48 and 72 h were 25.8 +/- 3.79 per cent and 11.2 +/- 0.58 per cent, 72.9 +/- 2.44 and 14.3 +/- 1.88 per cent, 93.5 +/- 0.54 per cent and 18.0 +/- 1.80 per cent respectively (P<0.001). All CDT (+ve) isolates induced DNA fragmentation. Apoptosis induced by CDT (+ve) C. jejuni was significantly greater than CDT (-ve) (26.3 +/- 3.49 % vs. 10.4 +/- 1.01% at 24 h, 43.9 +/- 2.40% vs. 17.6 +/- 0.88% at 48 h, 68.4 +/- 1.61% vs. 28.4 +/- 1.62% at 72 h); (P<0.001). INTERPRETATION & CONCLUSION: The present study shows that CDT (+ve) C. jejuni contributes to the pathogenesis through epithelial cell G2/M phase arrest and apoptosis.
BACKGROUND & OBJECTIVE:Campylobacter jejuni is the leading cause of gastroenteritis worldwide; cytolethal distending toxin (CDT) being an important virulence determinant. As its role in pathogenesis remains unclear, this study aims to investigate cell cycle arrest and apoptosis by CDT (+ve) and CDT (-ve) C. jejuni isolates on HeLa cells. METHODS: Culture supernatants and lysates from 10 C. jejuni isolates [CDT (+ve) and CDT (-ve), five each] were incubated with HeLa cells. CDT activity on HeLa cells was confirmed by cell distension, cell cycle arrest by flowcytometry, and apoptosis by DNA fragmentation and flowcytometry. RESULTS: Culture supernatant and lysate of only CDT (+ve) C. jejuni isolates produced cell distension. For CDT (+ve) and CDT (-ve) isolates, the cells at G2/M phase after 24, 48 and 72 h were 25.8 +/- 3.79 per cent and 11.2 +/- 0.58 per cent, 72.9 +/- 2.44 and 14.3 +/- 1.88 per cent, 93.5 +/- 0.54 per cent and 18.0 +/- 1.80 per cent respectively (P<0.001). All CDT (+ve) isolates induced DNA fragmentation. Apoptosis induced by CDT (+ve) C. jejuni was significantly greater than CDT (-ve) (26.3 +/- 3.49 % vs. 10.4 +/- 1.01% at 24 h, 43.9 +/- 2.40% vs. 17.6 +/- 0.88% at 48 h, 68.4 +/- 1.61% vs. 28.4 +/- 1.62% at 72 h); (P<0.001). INTERPRETATION & CONCLUSION: The present study shows that CDT (+ve) C. jejuni contributes to the pathogenesis through epithelial cell G2/M phase arrest and apoptosis.
Authors: B B Fonseca; I L Santos; D A Rossi; R T Melo; T G Araújo; C U Vieira; E P Mendonça; M E Beletti Journal: Indian J Microbiol Date: 2012-11-11 Impact factor: 2.461
Authors: Nayyer Taheri; A K M Firoj Mahmud; Linda Sandblad; Maria Fällman; Sun Nyunt Wai; Anna Fahlgren Journal: Sci Rep Date: 2018-11-19 Impact factor: 4.379