Review – Recent advances in the research on inflammation, immunity, and vaccines related to Helicobacter pylori

Abstract

Helicobacter pylori can persistently colonize the human gastric mucosa and cause chronic gastritis, peptic ulcers and gastric cancer. These illnesses develop in a small proportion of infected individuals usually in adulthood, decades after the acquisition of infection in childhood. H. pylori triggers both the innate and adaptive immune systems, with a Th1/Th17 cells biased and regulatory T cells response, however, H. pylori successfully evades the immune system. Insights into H. pylori-induced inflammation and immunity are key to a better understanding the pathogenesis of H. pylori infection and to designing and evaluating preventive and therapeutic vaccines. This review presents the main advances in H. pylori-induced inflammation, immunity, and vaccines between March 2022 and April 2023. Multiple studies characterized the interaction between pattern recognition receptors and Helicobacter sp. such as Toll-like receptors 9, 7 and 8, AIM2, and STING. The interaction with host cells via annexins was also described, as well as with several proinflammatory and proangiogenic factors involved in angiogenesis. Additional studies focused on the role of CD8+ T cells in H. pylori infection, others addressed Th22 CD4+ cells and regulatory B cells. Currently, there is no licensed anti-H. pylori vaccine. H. pylori vaccine studies were all in pre-clinical phases and focused on antigen discovery, construction, and evaluation of new vaccine candidates, showing promising results in terms of immunogenicity and efficacy in mouse models.

Keywords

• helicobacter pylori
• inflammation
• pattern recognition receptors
• vaccines
• cd4+ t cells
• cd8+ t cells
• regulatory t cells.