The role of outer inflammatory protein A (OipA) in vaccination of theC57BL/6 mouse model infected by Helicobacter pylori.

BACKGROUND/AIM Outer inflammatory protein A (OipA) is an important adhesin of Helicobacter pylori. Our goal was to assess the role of OipA in protection of C57BL/6 mice against H. pylori. MATERIALS AND METHODS C57BL/6 mice were mucosally immunized with recombinant OipA protein, OipA + propolis, propolis, and phosphate-buffered saline. After vaccination, anti-OipA IgA was measured. Mice were challenged three times with 5 × 107 CFU of the H. pylori B19 strain. Two weeks later, bacterial colonization and inflammation in the stomach was analyzed using standard methods. RESULTS The CFU number in the OipA group was significantly (P < 0.05) lower than that of the control. The CFU number in the OipA + propolis group was higher than those of the OipA and propolis groups. IgA titers were significantly higher (P 6lt; 0.0001) in the OipA group compared to the control and OipA + propolis groups. Propolis did not play an adjuvant effect but it interfered with the efficient vaccine effect of OipA. CONCLUSION Results show the effect of vaccination by OipA in protection of the mouse model and the importance of OipA in H. pylori pathogenesis. OipA may be proposed as a suitable oral vaccine candidate against H. pylori infection; however, further study is required to determine adjuvant or adverse effects of propolis toward OipA.