Synthesis and immunogenicity of aHelicobacter pylorilipopolysaccharide-based conjugate

Helicobacter pyloriinfection in humans is responsible for the onset of severe gastric disorders and a vaccine would be an improvement over current antibiotic-based treatments. Lipopolysaccharide (LPS; O-chain PS[arrow right]core[arrow right]lipid A) is a mainH. pyloricell wall component, whose O-chain PS exhibits molecular mimicry and therefore any LPS-based vaccine cannot contain O-chain epitopes. Here, the conjugation of de-lipidatedH. pyloriO:2 LPS to BSA and its immunogenicity in mice is described. IgG antibodies were observed to recognize the LPSs of representativeH. pyloriserotypes O:1, O:2 and O:5, and more significantly, the core region ofH. pylori. This study showed that a monovalentH. pyloriLPS conjugate can elicit antibodies that recognize other serotype-specificH. pyloriLPSs and specifically the structurally conserved LPS inner-regions.