Intestinal epithelial barrier and mucosal immune system

The intestinal epithelial barrier and mucosal immune system constitute a critical physiological interface that maintains homeostasis between the host and the external environment. The barrier is composed of a physical layer of epithelial cells connected by tight junctions, a chemical layer of mucus and antimicrobial peptides, and a biological layer of commensal microbiota (NIH, 2016). Beneath this, the mucosal immune system, including the gut-associated lymphoid tissue (GALT), monitors luminal contents to distinguish between harmless antigens and pathogens (Nature Reviews, 2016). Dysregulation of this integrated system leads to increased intestinal permeability and aberrant immune activation, which are central to the pathogenesis of inflammatory bowel disease (IBD), celiac disease, and various systemic inflammatory conditions (Frontiers in Immunology, 2019). Therapeutic interventions typically target specific components of this system, such as proinflammatory cytokines (e.g., TNF-alpha) or leukocyte trafficking molecules (e.g., α4β7 integrin), to restore barrier integrity and immune tolerance (MDPI, 2024). Emerging strategies also focus on direct barrier reinforcement and microbiome modulation to promote mucosal healing and long-term remission (NIH, 2024). Understanding the crosstalk between these components is essential for developing treatments that address the root causes of mucosal inflammation.

Other names

Gut barrierIntestinal mucosal barrierGut-associated lymphoid tissueGALTIntestinal immune system

Modulation of cytokine signaling, inhibition of leukocyte trafficking to the mucosa, and reinforcement of epithelial tight junction integrity.