Dietary Antigen Interaction with Intestinal Epithelial Cells

Growing interest has focused on the cellular and molecular mechanisms by which dietary antigens cross the intestinal epithelium and shape tolerance, sensitization, and allergic responses. This review summarizes the current understanding of antigen transport across the intestinal epithelium in steady state and food-allergic conditions.

Luminal antigens cross the intestinal epithelium via M cell-mediated transcytosis, transepithelial dendrites, paracellular leaks, receptor-mediated transcytosis, and goblet cell- and secretory antigen passages (GAPs & SAPs). These processes deliver antigens to the underlying immune compartment and drive tolerogenic or sensitizing immune responses. Recent studies have identified an association between dysregulated antigen transport mechanisms and development of food sensitization and reactivity, and these processes are regulated by cytokines and arachidonic acid-derived metabolites. Elucidating the mechanistic distinction between homeostatic and pathological antigen transport could identify novel targets that modulate antigen bioavailability to immune cells, potentially offering intervention strategies for food allergy prevention and treatment.