Elicitation of IgY in chicken egg yolk by recombinant fragments of UreC and its efficacy against Helicobacter pylori

Background: Helicobacter pylori multiplies and causes infection in human gastric mucosal layer. New approaches have focused on using specific treatments, such as immunotherapy, to limit this infection. Urease, as one of the most important virulent and antigenic factors of the bacterium, is a suitable target for this purpose. Patients and methods: In order to prepare recombinant proteins, the synthetic genes for total ureC protein (UreCt) and its N (ureCn) and C (ureCc) terminal fragments were ligated into pET28a. The recombinant proteins were expressed in E. coli BL21(DE3). White leghorn hens were injected with the purified recombinant proteins. IgY recovered from egg yolk, using PEG precipitation. Finally, urease neutralizing ability of the antibodies was evaluated by urease activity assay in presence of the purified IgY. Results: SDS-PAGE analysis revealed a good expression and purification of the recombinant proteins. Indirect ELISA observation demonstrated high antibody titer in sera and egg yolks and high ability of IgY Anti-UreCt and IgY Anti- UreCc antibodies in recognition of urease subunit C. Anti-UreCT and Anti-UreCc IgYs were more potential H.pylori urease inhibitors than Anti-UreCn. Conclusion: While all three UreC fragments induce prophylactic responses. UreCt and UreCc possess almost equal responses. Anti-UreCc IgY has advantage of smaller size and is preferred for its activity and easier protein recovery and purification process. These features emphasize on importance of simpler, easier and cost effective antibody production.