UreBimmunodominant epitope‐specificCD8+T‐cell responses were beneficial in reducing gastric symptoms inHelicobacter pylori‐infected individuals

Abstract

AbstractBackground and aimsAlthoughHelicobacter pyloriis recognized as an extracellular infection bacterium, it can lead to an increase in the number of CD8+T cells after infection. At present, the characteristics ofH. pyloriantigen‐specific CD8+T cells and the epitope response have not been elucidated. This study was focused on putative protective antigen UreB to detect specific CD8+T‐cell responses in vitro and screen for predominant response epitopes.MethodsThe PBMCs collected fromH. pylori‐infected individuals were stimulated by UreB peptide pools in vitro to identify the immunodominant CD8+T‐cell epitopes. Furthermore, their HLA restriction characteristics were detected accordingly by NGS. Finally, the relationship between immunodominant responses and appearance of gastric symptoms afterH. pyloriinfection was conducted.ResultsUreB‐specific CD8+T‐cell responses were detected inH. pylori‐infected individuals. Three of UreB dominant epitopes (A‐2 (UreB443–451: GVKPNMIIK), B‐4 (UreB420–428: SEYVGSVEV), and C‐1 (UreB5–13: SRKEYVSMY)) were firstly identified and mainly presented by HLA‐A*1101, HLA‐B*4001 and HLA‐C*0702 alleles, respectively. C‐1 responses were mostly occurred inH. pylori‐infected subjects without gastric symptoms and may alleviate the degree of gastric inflammation.ConclusionsThe UreB dominant epitope‐specific CD8+T‐cell response was closely related to the gastric symptoms afterH. pyloriinfection, and the C‐1 (UreB5‐13) dominant peptides may be protective epitopes.