Antibody-independent protective mucosal immunity to gastric Helicobacter infection in mice

Helicobacter pylori infection of the gastric mucosa can result in gastritis and peptic ulcer disease. Although vaccination can induce protective immunity in animal models of Helicobacter infection, the mechanism(s) of protective immunity has not been fully elucidated. This study was designed to determine whether humoral immune responses are required for protective Helicobacter immunity. IgA-deficient or immunoglobulin-deficient mice were orally immunized against Helicobacter felis and then challenged with live H. felis. Both groups were protected at levels comparable to that of wild-type mice. Additionally, inflammation was equivalent in extent and character between wild-type and antibody-deficient mice. Therefore antibody-independent mechanisms of immunity can protect mice against gastric Helicobacter infection. (C) 1999 Academic Press.