Pathogenicty and immune prophylaxis of cag pathogenicity island gene knockout homogenic mutants.
OBJECTIVE
To clarify the role of cag pathogenicity island (cagPAI) of Helicobacter pylori (H pylori ) in the pathogenicity and immune prophylaxis of H pylori infection.


METHODS
Three pairs of H pylori including 3 strains of cagPAI positive wildtype bacteria and their cagPAI knockout homogenic mutants were utilized. H pylori binding to the gastric epithelial cells was analyzed by flow cytometry assays. Apoptosis of gastric epithelial cells induced by H pylori was determined by ELISA assay. Prophylaxis effect of the wildtype and mutant strains was compared by immunization with the sonicate of the bacteria into mice model.


RESULTS
No difference was found in the apoptasis between cagPAI positive and knockout H pylori strains in respective of the ability in the binding to gastric epithelial cells as well as the induction of apoptosis. Both types of the bacteria were able to protect the mice from the infection of H pylori after immunization, with no difference between them regarding to the protection rate as well as the stimulation of the proliferation of splenocytes of the mice.


CONCLUSIONS
The role of cagPAI in the pathogenicity and prophylaxis of H pylori infection remains to be cleared.
Institute for Digestive Medicine, Nan Fang Hospital, the First Military Medical University, Guangzhou 510515, Guangdong Province, China. xj0302@fimmun.com
Huan-Jian
HJ
Lin
Jing
J
Xue
Yang
Y
Bai
Ji-De
JD
Wang
Ya-Li
YL
Zhang
Dian-Yuan
DY
Zhou
D000818:Animals; D000942:Antigens, Bacterial / Q000235:genetics*; D017209:Apoptosis; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000235:genetics*; D004848:Epithelium / Q000276:immunology / Q000382:microbiology; D016481:Helicobacter Infections / Q000276:immunology* / Q000382:microbiology*; D016480:Helicobacter pylori / Q000235:genetics* / Q000276:immunology*; D007114:Immunization; D051379:Mice; D013154:Spleen / Q000276:immunology; D013270:Stomach / Q000276:immunology / Q000382:microbiology
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C080866:cagA protein, Helicobacter pylori