THE GROES HOMOLOG OF HELICOBACTER-PYLORI CONFERS PROTECTIVE IMMUNITY AGAINST MUCOSAL INFECTION IN MICE

Helicobacter pylori is an important etiologic agent of gastroduodenal disease. In common with other organisms, H. pylori bacteria express he at shock proteins that share homologies with the GroES-GroEL class of proteins from Escherichia coli, We have assessed the heat shock protei ns of H. pylori as potential protective antigens in a murine model of gastric Helicobacter infection, Orogastric immunization of mice with r ecombinant H. pylori GroES- and GroEL-like proteins protected 80% (n = 20) and 70% (11 = 10) of animals, respectively, from a challenge dose of 10(4) Helicobacter felis bacteria (compared to control mice, P = 0 .0042 and P = 0.0904, respectively). All mice (n = 19) that were immun ized with a dual antigen preparation, consisting of H, pylori GroES-li ke protein and the B subunit of H. pylori urease, were protected again st infection, This represented a level of protection equivalent to tha t provided by a sonicated Helicobacter extract (P = 0.955), Antibodies directed against the recombinant H. pylori antigens were predominantl y of the IgG1 class, suggesting that a type 2 T-helper cell response w as involved in protection, This work reports a protein belonging to th e GroES class of heat shock proteins that was shown to induce protecti ve immunity. In conclusion, GroES-like and urease B-subunit proteins h ave been identified as potential components of a future H. pylori subu nit vaccine.