Cloning, expression and preliminary clinical application of heat shock protein A gene of human Helicobacter pylori

Abstract

Objective To obtain the recombinant human Helicobacter pylori (Hp) heat shock protein A(HspA) and apply it to clinical diagnosis. Methods The HspA DNA was amplified with PCR from the chromosomal DNA of clinically isolated H. pylori and then inserted into plasmid PinPoint TM Xa 3. The vector pPin HspA was transfected to E.coli JM109 for recombinant protein which were later analyzed with SDS PAGE, Western blot. The purified protein was used with ELISA to test HspA antibody in patients with Hp infection before and after eradication treatment. Results The cloned DNA consisted of 354 base pairs, and encoded 118 amino acid residues with a molecular weight of 14×10 3. Recombinant HspA was confirmed by the sera of Hp infected patients and rabbits with Western blot. The levels of serum anti recombinant HspA antibodies were declined significantly after eradication treatment, but changes of Hp antibodies were not apparent until almost 6 monthes later. Conclusion The identified recombinant HspA protein estabtishes a basis for experimental study on diagnosis, prevention and treatment of Hp infection.