Experimental study of BALB/c mice orally immunized by recombinant Hp vaccine
Objective To study the duration of the immune response and long term protective efficacy of immunization with recombinant H.pylori vaccine. To investigate primary immune mechanism. Methods Specific antibody levels were detected with ELISA. Moreover, specific antibody secreting cells (ASCs) in Payer′s patch were assayed by ELISPOT. The expressions of T cell cytokines mRNA in spleen were also detected with RT PCR. H.pylori infection were assayed by gastric H.pylori culture, histology and urease assay. Results (1) A high level of specific antibody in gastric mucosa, intestinal mucosa, trachea mucosa and serum was found in vaccine group. (2) Specific ASCs of Payer′s patch in vaccine group were significantly increased. (3) The expression levels of IFN γ, IL 4 mRNA in vaccine group obviously increased after stimulation by antigens. (4) Over the 30 week period, protection ranged from 86.7% 92.8% post challenge in vaccine group. Conclusion BALB/c mice orally immunized with recombinant H.pylori vaccine results in a long lasting protective immunity against challenge with H.pylori . After orally immunization with recombinant H.pylori vaccine, it may induce a T H1/T H2 type immune response.