Identification and evaluation of protection effect of B-cell immunodominant epitopes of campylobacter jejuni PEB1

To provide detail data for Campylobacter jejuni (C.jejuni) vaccine research, this study performed epitope prediction analysis technology to screen the B cell immunodominant epitopes of C. jejuni adhesion protein PEB1 and evaluated the immunoprotective effect. The overlapping peptides were synthesized and B-cell immunodominant epitopes of PEB1 were identified by ELISA. BALB/c mice were immunized with the immunodominant epitopes of PEB1 conjugated with KLH plus CFA/IFA. The titers for immunodominant peptide antiserum against PEB1 were detected by ELISA. The bacterial colonization and the relative expression level of TNF-α were analyzed after the mice challenged with C. jejuni 11,168. The function of antibody induced by immunodominant PEB1 epitopes were performed by opsonophagocytic killing. The results showed that PEB155-72aa, PEB197-114aa, PEB1211-228aa were the immunodominant peptides and could induce strong B cell mediated humoral immunity response. Antiserum from the immunodominant peptides group significantly enhanced opsonize phagocytosis than CFA/IFA group (P<0.01). Both the bacterial burdens and the TNF-α expression level in the immunodominant peptides groups were significantly lower than those in the control group (P<0.01). Moreover, the immune protective effect of the three immunodominant peptides depended on the B cell immunity response in vivo study. In conclusion, three specific B cell immunodominant epitopes with good immunogenicity and immunoprotection efficacy were successfully identified, indicating that could be used in the anti- C. jejuni vaccine research and development.