Synthetic self-adjuvanted lipopeptide vaccines conferred protection against Helicobacter pylori infection
Helicobacter pylori (H. pylori) colonize the stomach epithelium of half the world's population and are responsible for a variety of digestive diseases and even stomach cancer. The protection against H. pylori infection depends primarily on the antigen-mediated mucosal and T cell responses. We hypothesized that lipopeptide vaccines obtained by covalently conjugation of Pam2Cys with strong mucosal adjuvant activity to the immunodominant epitope from protective antigens could induce protective responses against H. pylori infection. In this study, the synthetic lipopeptide vaccines, Hp4 (Pam2Cys modified UreB T cell epitope) and Hp10 (Pam2Cys modified CagA T/B cell combined epitope), induced the BMDCs maturation in vitro by activating a variety of pattern recognition receptors such as TLR, NLR and RLR. In addition, lipopeptide vaccines stimulated BMDCs to secret cytokines that have the potential to modulate T cell activation and differentiation. Although intranasal immunization with Hp4 or Hp10 elicited robust epitope-specific T cell responses in mice, only Hp10 conferred protection against H. pylori infection, possibly due to the fact that Hp10 also induced substantial specific sIgA response at mucosal sites. Interestingly, when two lipopeptide vaccines were administrated in combination, Hp4 elevated the protective response against H. pylori infection of Hp10, which was characterized by better protective effect and enhanced specific T cell and mucosal antibody responses. Our results suggest that synthetic lipopeptide vaccines based on the epitopes derived from the protective antigens are promising candidates for protection against H. pylori infection. Overall design: BMDCs were co-incubated with PBS, Hp4 or Hp10 for 48 hours, and 1ml Trizol was added to each well for re-suspension before collection. RNA-seq [22] library was generated and sequenced by Shanghai Sangon. The raw data of sequencing were evaluated by FastQC. Trimmomatic was used for quality cutting to obtain relatively accurate and effective data.