Figure 3. Groups of 6 or 7 Balb/c mice were left unimmunized (PBS) or were immunized intranasally 4 times with H. pylori lysate+5 µg of CT adjuvant, a fusion protein of CTA1-UreB3T-DD containing three copies of UreB237–251, UreB237–251 peptide alone+5 µg of CT adjuvant, or a mixture of UreB237–251 plus the UreB B321–339 peptide+5 µg of CT adjuvant, as described in Fig. 1.

Four weeks after completion of immunization a separate group of 3 naïve mice were left unchallenged (Naïve) and all other mice were challenged twice over three days with ca 2×10⁷ cfu of H. pylori SS-1 and 3 weeks later mice were killed and recall splenic IFNγ responses in supernatants from lysate stimulated cultures with unstimulated background controls subtracted (A), serum IgG anti-H. pylori antibody responses (B) and gastric H. pylori cfu/g of stomach tissue (C) were determined. For IFNγ determinations (A) only one experiment with CTA1-UreB3T-DD was included, but apart from that these are representive data from at least 3 identical experiments giving similar results. ANOVA was used for statistical analysis :* p<0.05, ** p<0.01 and ***p<0.001.