Gastrointestinal mucosal immune system

The **gastrointestinal mucosal immune system** is not a single molecular or protein target but rather a highly organized system comprising various immune cells (e.g., dendritic cells, macrophages, T and B lymphocytes, plasma cells), tissues (such as Peyer’s patches, isolated lymphoid follicles, lamina propria), and anatomical structures within the gastrointestinal tract[1][2][3][4][5]. Its major role is to maintain immune homeostasis by mounting protective responses against pathogens, inducing tolerance to harmless dietary antigens and commensal microbiota, and serving as a barrier to infection[1][2][5][6]. The system includes specialized lymphoid tissues collectively called mucosa-associated lymphoid tissue (MALT), with gut-associated lymphoid tissue (GALT) representing the major inductive site for GI tract immune responses[1][3][5]. Key features include the predominance of secretory IgA antibodies, specialized antigen transport via M cells, and a unique composition of immune cell subsets compared to systemic immunity[2][4][5]. Dysregulation of this system contributes to a variety of diseases including inflammatory and autoimmune disorders, infections, allergies, and some cancers[1][2][5][6]. This entity is not a single molecular drug target but an entire functional immune system at the mucosal interface of the gut.

Other names

Mucosal immune system (gastrointestinal)GI mucosal immunityGut-associated lymphoid tissue (GALT, as a subset)Mucosa-associated lymphoid tissue (MALT, as a component)