The intestinal mucosa represents important primary interface with the external environment. The mucosal immunity posses the ability to differentiate between non-pathogenic microbial agents (non-inflammatory immune reaction) and pathogens (inflammatory immune response). The defence mechanisms of intestinal mucosa due to extensive nonadaptive and adaptive immune reactions facilitate both inductive and effector side of immune response. The oral tolerance is dependent on the mucous intestinal immunity and modulates the systemic immune reactivity.

        Key words: enterocytes, Paneth cells, mucous immunity, defensins, M cells.