Intestinal and systemic immune system

The intestinal and systemic immune systems represent a complex, integrated network of cells, tissues, and signaling molecules responsible for maintaining host homeostasis and defending against pathogens (Mowat & Agace, 2014, Nature Reviews Immunology). The intestinal immune system, largely comprised of gut-associated lymphoid tissue (GALT), is unique in its requirement to maintain immunological tolerance toward commensal microbiota and dietary antigens while remaining poised to respond to enteric pathogens (StatPearls, 2023). The systemic immune system provides broader protection through the spleen, peripheral lymph nodes, and circulating leukocytes. In many inflammatory and autoimmune conditions, such as inflammatory bowel disease (IBD), the balance between these systems is disrupted, leading to chronic inflammation (NIH, 2022). Therapeutic intervention typically involves targeting specific molecular mediators within these systems, such as tumor necrosis factor (TNF) or specific integrins, rather than the system as a whole (Danese et al., 2015). Understanding the crosstalk between mucosal and systemic immunity is critical for developing targeted therapies that minimize systemic side effects while maximizing local efficacy.

Other names

Gut-associated lymphoid tissueGALTMucosal immune systemSystemic immunity

Drugs do not target the system as a whole but rather specific molecular components such as cytokines (e.g., TNF-alpha, IL-12/23), cell adhesion molecules (e.g., alpha4beta7 integrin), or signaling kinases (e.g., JAK) to modulate immune activity.