Decoding the Ability of Helicobacter pylori to Evade Immune Recognition and Cause Disease

Helicobacter pylori (H pylori) successfully and chronically colonizes the gastric mucosa of approximately 43% of the world's population. Infection with this organism is the strongest known risk factor for the development of gastric cancer, and disease development is dependent on several interactive components. One H pylori determinant that augments cancer risk is the strain-specific cag type IV secretion system, which not only translocates a pro-inflammatory and oncogenic protein, CagA, into host cells but also DNA, peptidoglycan, and a lipopolysaccharide intermediate, heptose-1,7-bisphosphate. However, cognate interactions between certain microbial and host constituents can also attenuate pro-inflammatory responses, and H pylori harbors multiple effectors that function differently than the respective counterparts in other mucosal pathogens. In this review, we discuss current data related to mechanisms utilized by H pylori to evade the immune response, sustain its longevity in the host, and further disease progression, as well as implications for developing targeted, immune-based eradication strategies.