Oral vaccination with liposome-encapsulated recombinant fusion peptide of urease B epitope and cholera toxin B subunit affords prophylactic and therapeutic effects against H. pylori infection in BALB/c mice.

A new fusion peptide CtUBE of cholera toxin B subunit and Helicobacter pylori urease B subunit epitope was expressed in Escherichia coli. With this fusion peptide, an oral liposome vaccine against H. pylori infection was prepared and evaluated in BALB/c mice. Based on the results of urease tests, quantitation of culturable bacteria colonies in mice stomachs and histological identification of gastritis, the mice were protected significantly after intragastric vaccination with this CtUBE liposome vaccine, which increased the content levels of specific anti-urease serum IgG and mucosal IgA for both prophylactic and therapeutic vaccination protocols. These results showed that the fusion peptide CtUBE retained immunogenicity and could be used as antigen in the development of an oral vaccine against H. pylori infection.