Helicobacter pylori HspA Heat-shock Protein Gene Cloning, Expression and Immunogenicity

Helicobacter pylori is the causative agent of gastritis and peptic ulcer in human. The heat-shock protein A (HspA)may stimulate the immunoresponse protecting human body against challenge of H.pylori. The gene encoding the structural A subunit of H.pylori heat-shock protein was amplified from H.pylori chromosomal DNA by PCR, and was inserted in the prokaryotic expression vector pET-22b(+), and then was transformed into the BL-21(DE3)E.coli strain to express the HspA recombinant protein. HspA gene was measured to be 354 base pairs, and the recombinant protein gene encoded polypeptides of 118 amino acid residues, corres-ponding to calculated molecular weight of 15 kD. Western blot analysis of HspA recombinant protein was confirmed that it could be specifically recognized by the serum of H.pylori-infected patients, and could also be re-cognized by the serum of immunized Balb/c mice with HspA itself. This result suggests that HspA may be an effective protein vaccine for prevention and treatment of the infection of H.pylori.