ABSTRACT
The intestinal processing of antigen absorption and handling and the local secretory immune reaction, including nonimmunological factors, are important components that influence the mucosal barrier of the gastrointestinal tract. The mucosal immune system is a significant regulator of the homeostatic balance in the gastrointestinal tract. Intact antigenic macromolecules from food protein can traverse the epithelium of the gastrointestinal tract, generating active secretion of immunoglobulin A (IgA) with immune complex formation. The humoral immune system plays a major role in mucosal immunity via immunoglobulin E (IgE) and IgA bearing cells in lymphoid tissue. Immune complexes can activate complement, resulting in either activation of mast cells or chemotaxis of polymorphonuclear leukocytes with release of mast cell mediators or proteolytic enzyme release. Cytokine production from peripheral T cells was found to be abnormal after mitogenic stimulation, which may contribute to elevated IgE level and eosinophilia.
