| Summary: | 碩士 === 國立臺灣海洋大學 === 食品科學系 === 96 === Helicobacter pylori (H. pylori) is the microorganism involved in the pathogenesis of human active chronic gastritis, peptic and duodenal ulcer diseases and gastric cancer. The treatment of H. pylori infection includes antibiotics and combination with proton pump inhibitors, but the emergence of antibiotic resistance limit the pharmacological therapy for H. pylori infection. The development of appropriate intervention strategies through vaccination sets the stage for preventing and control of H. pylori infection. This study investigates three kinds of oral vaccines based on live attenuated Salmonella, chitosan carrier and immunoglobulin Y (IgY) to prevent H. pylori infection. A prokaryotic (pUC19) or an eukaryotic (pCJ-3) vector expressing H. pylori urease B gene was constructed and transformed to the attenuated Salmonella typhimurium SL1344. These plasmids can be maintained 80 and 40 generations in Salmonella typhimurium SL1344, respectively. After oral administration to C3H/HeN mice, both types have shown induction of specific anti-urease B immune responses that is relevant to Th2 immune pathway. The oral vaccinated mice with urease B peptide/chitosan complexes can induce specific anti-urease B immunity and the immune pathway toward Th2 response. Ten mg/ml of encapsulated anti-urease B IgY has shown to reduce 72% urease activity of H. pylori in vitro. Orally administered mice individually with these three types of oral vaccines can effectively reduce H. pylori infection on gastric mucosa in both prophylactic and therapeutic experiments by measuring urease activity and urease B gene expression with real-time PCR. So, these three types of oral vaccines will be the potential strategies to prevent H. pylori infection from occurring.
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