Required tasks of the mucosal immune
1. Provide barrier function against penetration of infectious and immunogenic components into the drculation (barrier)
2. Provide protection from harmful microbiaJ pathogens (antHnfection)
3. Exhibit Iow reactivity to harmless antigens preeent on mucosal surfaoe (oni or muooml tolmiiM)
4. Maintain mucosal homeostasis (immunoregulatory function)