CpG-Oligodeoxynucleotide is the ideal adjuvant for development of a Helicobacter pylori vaccine / 中华消化杂志

ABSTRACT

Objective To investigate whether a novel mucosal adjuvant (DNA containing six base pair motifs consisting of an unmethylated CpG dinucleotide flanked by two 5′ purines and two 3′ pyrimidines, CpG Oligodeoxynucleotide, CpG ODN),which has not been shown to have significant toxicity,could be an ideal mucosal adjuvant for the development of a H. pylori vaccine in mice model. Methods C57BL/6 mice were orally or intranasally immunized with H. pylori whole cell sonicate(WCS) / cholera toxin (CT) or WCS /CpG ODN, and the corresponding control groups were set. Mice were dosed once a week for four weeks. One week after the last immunization, all animals were challenged by live H. pylori (5?10 8) three times in a five day duration. Two and 8 weeks after the last challenge, all animals were sacrificed to examine infection of H. pylori. Sera, saliva, gastric juice were collected to measure the concentrations of IgG, IgG1, IgG2a and IgA by ELISA. Results The protecting rates against H. pylori infection were 75%(9/12), 70% (7/10) and 0 (0/10) in the group of WCS/CT orally, WCS/CpG ODN intranasally and WCS/CpG ODN orally, respectively. Significantly higher levels of serum IgG2a antibody was found in the group immunized with WCS plus CpG ODN than those found in the sham immunized controls ( P