Cloning and Expression of Helicobacter pylori HpaA Gene

Objective: Helicobacter pylori is associated with chronic gastritis, peptic ulcers, gastric adenocarcinoma and gastric mucosa-associated lymphoid tissue (MALT) lymphoma. Antibiotic therapies do not protect from potential re-infection and have a risk for development of drug resistance. Therefore, prophylactic vaccine mediated protection against H. pylori is an attractive clinical interest. H. pylori adhesin A (HpaA) is a conserved surface lipoprotein and plays important roles in the pathogenesis of infection. In this study the recombinant protein (rHpaA) was over-expressed in E.coli. Materials and Methods: The hpaA gene was amplified by PCR. Prokaryote expression vector pET28a-hpaA was constructed, and used to transform E.coli BL21DE3. The expression of recombinant protein induced by IPTG was examined by SDS-PAGE. Western blot were used to determine immunoreactivity of rHpaA by a rabbit polyclonal antibodies against whole cell of H. pylori. Results: The hpaA gene nucleotide sequence in the recombinant plasmid vector of pET-28- a-hpaA was consistent with that of H.pylori hpaA as published in the GenBank. SDS-PAGE demonstrated that the constructed prokaryotic expression efficiently produced rHpaA at the 1.5 mmol/L of IPTG. HpaA fusion protein was able to react with the rabbit polyclonal antibody against whole cells of H. pylori. Conclusion: A prokaryotic expression system pET-28a-hpaA-BL21 with high efficiency of H. pylori hpaA gene was successfully established and the HpaA fusion protein showed satisfactory immunoreactivity. These results indicate that production of a specific recombinant protein is an alternative and potentially more expeditious strategy for development of H. pylori vaccine.