Mutation of iceA in Helicobacter pylori compromised IL-8 induction from human gastric epithelial cells.
IceA of Helicobacter pylori (H. pylori) has been suggested as a virulence factor for the bacteria, but its pathogenic role remains unelucidated. Here, we examined the effect of iceA mutation on the secretion of IL-8 by human gastric epithelial cells. We also investigated whether the changes in IL-8 production caused by iceA mutation were associated with impaired adherence of H. pylori to the epithelial cells or with impaired apoptosis of these cells. The iceA mutant strain was constructed from wildtype H. pylori strain by insertional mutagenesis of iceA. The human gastric epithelial cells SGC7901 were infected with wildtype or mutant H. pylori for appropriate lengths of time. The adherence of the bacteria to the epithelial cells was examined by fluorescent microscopy using an anti-H. pylori antibody and flow cytometry. The apoptosis of the epithelial cells was studied by annexin-V staining and flow cytometry. The production of IL-8 by SGC 7901 cells was determined by ELISA. We found that iceA mutation was associated with significantly impaired production of IL-8 from the epithelial cells, which was not due to impaired adherence by the bacteria to the epithelial cells as wildtype and mutant H. pylori exhibited similar levels of binding to the epithelial cells. Furthermore, inactivation of iceA did not affect the apoptotic cell death of SGC7901. Our findings indicate that iceA may contribute to the pathogenicity of H. pylori by modulating the production of IL-8 by host epithelial cells.
Ma
Yi Jun
YJ
Department of Epidemiology, College of Public Health, Zhengzhou University, Zhengzhou, China. mayijunhn@yahoo.com.cn
Duan
Guang Cai
GC
Zhang
Rong Guang
RG
Fan
Qing Tang
QT
Zhang
Wei Dong
WD
D017209:Apoptosis; D001422:Bacterial Adhesion; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D002460:Cell Line; D004847:Epithelial Cells / Q000276:immunology* / Q000378:metabolism; D005753:Gastric Mucosa / Q000276:immunology* / Q000382:microbiology; D016481:Helicobacter Infections / Q000276:immunology* / Q000382:microbiology; D016480:Helicobacter pylori / Q000235:genetics* / Q000472:pathogenicity; D006801:Humans; D016209:Interleukin-8 / Q000276:immunology / Q000378:metabolism*; D016254:Mutagenesis, Insertional; D009154:Mutation
D001425:Bacterial Outer Membrane Proteins; D016209:Interleukin-8; C063113:ice nucleation protein