• Journal of Microbiology and Biotechnology
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• v.10 no.6
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• pp.865-872
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• 2000

Helocobacter phylori is the major cause of gastritis, peptic ulcer, and a principal risk factor for gastric cancer. As the firs step towards a vaccine against H. pylori infection, Hy.pylori urease was expressed and purified as a recombinant apoenzyme (rUrease) in E. coli. In order to develop an effective immunization protocol using rUrease, the host immune responses were evaluated after the oral immunization of mice with rUrease preparations plus cholera toxin relative to various conditions, such as the physical nature of the antigen, the frequency of the booster immunization, the dose of the antigen, and the route of administration. The protective efficacy was assessed using a quantitative culture following an H. pylori SS1 challenge. It was demonstrated that rUrease, due to its particulated nature, was more superior than the UreB subunit as a vaccine antigen. The oral immunization of rUrease elicited significant systemic and secretory antibody responses, and activated predominantly Th2-type cellular responses. The bacterial colonization was significantly reduced (~100-fold) in those mice immunized with three or four weekly oran doses of rUrease plus cholera toxin (p<0.05), when compared to the non-immunized/challenged controls. The protection correlated well with the elicited secretory IgA level against rUrease, and these secretory antibody responses were highly dependent on the frequency of the booster immunization, yet unaffected by the dose of the antigen (25-200$\mu\textrm{g}$). These results demonstrate the remarkable potential of rUrease as a vaccine antigen, thereby strengthening the possibility of developing an H. pylori vaccine for humans.

• Journal of Microbiology and Biotechnology
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• v.11 no.1
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• pp.35-39
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• 2001

A simple method for studying the lectin-like interactions between Helicobacter pylori and cultured human epithelial cell lines was developed using an enzyme-linked, biotin-streptavidin bacterial-adhesion assay. The present study suggests that this method is suitable for evaluating the participation of lectin interactions in the adhesion of H. pylori to cultured HeLa S3 and Kato III cells, both fixed and glycosidase-treated cells, as well as assessing glycoconjugated binding inhibition studies. The time-course and dose-dependent kinetics of the biotin-labeled H. pylori adhesion th the formaldehyde-fixed Hela S3 and Kato III cell lines exhibited saturation. In addition, the binding of the biotin-labeled H. pylori to the formaldehyde-fixed cultured cells was partially blocked by pre-incubation with glycoconjugates and polyclonal antibodies against a heparan sulfate binding protein from H. pylori.

• Proceedings of the Ginseng society Conference
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• 2005.05a
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• pp.8-11
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• 2005