Objective: To explore the improved immunological responses induced by an amino acid ABC transporter, permease protein PEB1 DNA vaccine primer-protein boost immunization method against Campylobacter jejuni.
Methods: The DNA vaccine pcDNA3.1(-)-PEB1 and protein vaccine were prepared, respectively. The female BALB/c mice were intranasally immunized with the vaccines. PBS and pcDNA3.1(-) were used as controls. The humoral and cellular immunological responses were detected in female BALB/c mice that were challenged by Campylobacter jejuni at 28 days after the final immunization.
Results: In the DNA primer-protein boost group at day 56, the stimulation index (SI) of lymphocytes was 2.625±0.275, serum IgG was (2.507±0.124) μg/mL, IL-4 in spleen supernatant was (377.47±14.560) pg/mL, IFN-γ in spleen supernatant was (258.920±13.472) pg/mL, and sIgA in genital tract was (80.351±5.769) ng/mL. All of them were significantly higher than those in controls (P<0.05). The DNA primer-protein boost vaccines induced the strongest levels of protection to BALB/c mice (91.53%).
Conclusion: The DNA primer-protein boost immunization could induce significant protective immunity against Campylobacter jejuni challenge. It could significantly enhance both humoral and cellular immunologic responses in BALB/c mice, compared with DNA vaccine or protein vaccine immunization alone.