Mucosal immune mechanisms against bacterial infection in the respiratory tract

Studies of immune responses to bacterial infections in animal models and clinical investigations has provided data for the development of a model of immune mechanisms of defence. In this model, intestinally-derived antigen specific B and T cells traffic to the lung following intestinal immunisation and the response enhanced by a booster immunisation delivered to the airways. In the immune state there is a defined coordination of the acquired and innate defences that lead to a rapid recruitment of neutrophils; upregulation of both neutrophil and macrophage activity; controlled release of proinflammatory cytokines; production of opsonising antibody; and a regulatory role in this process for T cells. This response results in rapid clearance of the bacteria and control of inflammation