Mucosal T lymphocytes

Mucosal T lymphocytes are a specialized subset of T cells located within the mucosal linings of the body, particularly the gastrointestinal, respiratory, and urogenital tracts (StatPearls, Mucosal Immunity). These cells are divided into two main compartments: intraepithelial lymphocytes (IELs), which reside within the epithelial layer, and lamina propria lymphocytes (LPLs), found in the underlying connective tissue (Nature Reviews Immunology, 2013). They serve as a primary defense mechanism, maintaining mucosal barrier integrity and responding to commensal and pathogenic microbes through cytokine secretion and direct cytotoxicity (PubMed, PMID: 23903472). In pathological conditions such as Crohn's disease and ulcerative colitis, dysregulated recruitment and activation of these cells lead to chronic tissue damage (Journal of Crohn's and Colitis, 2017). Modern therapeutic interventions target the homing receptors on these cells, such as integrin alpha-4 beta-7, to selectively inhibit their migration into inflamed mucosal tissues, thereby providing a localized anti-inflammatory effect (NEJM, 2013). While effective, this approach is considered a cell-population-level target rather than a single molecular target, as it involves various receptors and signaling pathways (FDA Label, Entyvio).

Other names

Intraepithelial lymphocytesLamina propria lymphocytesGALT T cellsMucosa-associated T cellsGut-homing T cells

Inhibition of lymphocyte trafficking to mucosal tissues by blocking adhesion molecules (e.g., Integrin alpha-4 beta-7) or chemokine receptors (e.g., CCR9) required for extravasation and homing (NEJM, 2013; Nature Reviews Immunology, 2013).