Expression and Antigenic Evaluation of Helicobacter pylori UreB Fragment

Background: Helicobacter pylori is a common cause of chronic infections worldwide. Helicobacter pylori urease is a multimeric enzyme with a molecular weight of 530 kDa, which is collected from two separate subunits of UreA (26.5 kDa) and UreB (61.7 kDa). Objectives: This study aimed to evaluate the antigenic properties of UreB recombinant protein as a vaccine candidate for the infected sera of humans and mice. Methods: In this study, the highly antigenic region of UreB gene (609 bp) was detected, using immunological bioinformatics for epitope mapping, amplified by polymerase chain reaction (PCR). Afterwards, the antigen was cloned, using a pBSK cloning vector and was inserted into a pET-32a expression vector; the target protein was then expressed and purified. Eventually, antigenicity was examined by immunoblotting on the sera of humans infected with H. pylori UreB recombinant protein. Results: The sequencing results of PCR were indicative of UreB gene cloning into the recombinant plasmid. Production of the protein was induced by isopropyl beta-D thiogalactopyranoside (IPTG), and the expressed protein was purified via dialysis, using the Ni-NTA kit. In addition, the recombinant protein with a molecular weight of 42 kDa was recognized by antibodies in Western blotting. Conclusions: The evaluation of antibodies was indicative of high antigenic properties for the immunogenic fragment, predicted by immunological bioinformatics. Therefore, UreB recombinant protein might be a proper antigen for the development of vaccines against H. pylori and other diagnostic kits.