Immunity, inflammation, and vaccines for Helicobacter pylori.

Helicobacter pylori colonizes mucosa, activates Toll-like and Nod-like receptors, and usually elicits a gastric T-helper 1/17 (Th1/Th17) type of immune response. Among several bacterial factors, the secreted peptidyl prolyl cis, trans-isomerase of H. pylori represents a key factor driving Th17 inflammation. A complex and fascinating balance between H. pylori and host factors takes part in the gastric niche and is responsible for the chronicity of the infection. Novel insights into the innate and adaptive responses against H. pylori, dealing with gastric epithelial cells, cytokines, and immune evasion have been elucidated over the past year and are discussed for the development of an effective vaccine.