Background: Helicobacter pylori is the most common bacteria causing chronic infections worldwide. An important virulence factor of H. pylori is a vacuolating cytotoxin (VacA) that induces the formation of acidic vacuoles in cytoplasm and damage to epithelial cells. The aim of this study was to examine the antigenic properties of the recombinant VacA of H. pylori in infected sera of mice and human.

Materials and Methods: In this experimental study, the highly antigenic region of VacA gene (1233 bp) was detected by bioinformatics methods, and it was amplified by PCR method and cloned into the pET32a expression vector. After expression and purification of the target protein, its antigenicity was studied by Western Blotting using human sera infected with H. pylori and sera from immunized mice infected with purified recombinant VacA.

Results: PCR and sequencing results showed that the target gene was correctly cloned into the recombinant vector. Antibodies used in Western Blotting indicated the production and expression of the recombinant protein (65kDa) with concentration of 2.1 mg/ml.

Conclusion: Recombinant VacA protein has antigenic and immunogenic properties thus, it is a proper candidate for designing H. pylori vaccine and diagnostic kits