Screening and identification of a novel B-cell neutralizing epitope from Helicobacter pylori UreB

Urease plays a crucial role in the survival and pathogenesis of Helicobacter pylori (H. pylori), and antibody neutralizing the urease activity may be implicated for the protection against H. pylori infection. Previously, a neutralizing monoclonal antibody (MAb) 6E6 against UreB of H. pylori was developed. In this work, we try to identify the B-cell epitope recognized by neutralizing MAb 6E6. Following screening a series of truncated proteins of UreB, an epitope was primarily localized in the aa 200–230 of UreB. Subsequently, we screened the overlapping synthetic peptides covering the aa 200–230 and identified a novel B-cell epitope (U211–225, IEAGAIGFKIHEDWG) that was recognized by specific MAb 6E6. The newly identified epitope may help understanding of the protective immunity against H. pylori and be implicated for vaccine development.