Mucosa-associated lymphoid tissue

The mucosa-associated lymphoid tissue (MALT) (also called mucosa-associated lymphatic tissue) is a diffuse system of small concentrations of lymphoid tissue found in various sub-mucosa membrane sites of the body, such as the gastrointestinal tract, thyroid, breast, lung, salivary glands, eye, and skin. MALT is populated by lymphocytes such as T cells and B cells, as well as plasma cells and macrophages, each of which is well situated to encounter antigens passing through the mucosal epithelium. In the case of intestinal MALT, M cells are also present, which sample antigen from the lumen and deliver it to the lymphoid tissue.