Mucosal immune system

The mucosal immune system is that portion of the immune system which provides protection to an organism's various mucous membranes from invasion by potentially pathogenic microbes. It provides three main functions: protecting the mucus membrane against infection, preventing the uptake of antigens, microorganisms, and other foreign materials, and moderating the organism's immune response to that material.

At birth, the neonate's mucosal immune system is relatively undeveloped, but the colonization of intestinal flora accelerates its development.

Because of its front-line status within the immune system, the mucosal immune system is being investigated for use in vaccines for various afflictions, including AIDS  and allergies.