Helicobacter pylori Vacuolating Cytotoxin A: Structure, Biological Functions, Genetic Polymorphisms, and Therapeutic Perspectives.

VacA (vacuolating cytotoxin A) is a key virulence factor in Helicobacter pylori infection, contributing to chronic gastritis and gastric adenocarcinoma. It induces vacuolation, disrupts cellular functions, and modulates immune responses, aiding bacterial survival in the harsh gastric environment. Genetic diversity in the vacA gene, particularly alleles like s1 and m1, is associated with more severe clinical outcomes. Recent advances in structural biology, especially cryo-electron microscopy, have revealed VacA's oligomeric structure and its ability to form anion-selective channels in host cell membranes, providing important insights into its cytotoxic mechanisms. Understanding VacA's structure and function is essential for unraveling its role in immune evasion and cellular damage. These findings also pave the way for targeted therapeutic strategies, such as subunit vaccines designed to neutralize VacA's immunosuppressive effects, potentially leading to more effective control of H. pylori infections.