| Description: |
Tumor necrosis factor receptor superfamily member 14 (TNFRSF14), also known as herpes virus entry mediator or HVEM, ATAR, CD270, HVEA, LIGHTR or TR2, regulates T-cell immune responses by activating inflammatory, as well as inhibitory signaling pathways. HVEM acts as a receptor for the canonical TNF-related ligand LIGHT (lymphotoxin-like), which exhibits inducible expression, and competes with herpes simplex virus glycoprotein D for HVEM [, ]. It also acts as a ligand for the immunoglobulin superfamily proteins BTLA (B and T lymphocyte attenuator) and CD160, a feature distinguishing HVEM from other immune regulatory molecules, thus, creating a functionally diverse set of intrinsic and bidirectional signaling pathways [].HVEM is highly expressed in the gut epithelium. Genome-wide association studies have shown that HVEM is an inflammatory bowel disease (IBD) risk gene, suggesting that HVEM could have a regulatory role influencing the regulation of epithelial barrier, host defense, and the microbiota []. Mouse models have revealed that HVEM is involved in colitis pathogenesis, mucosal host defense, and epithelial immunity, thus acting as a mucosal gatekeeper with multiple regulatory functions in the mucosa. HVEM plays a critical role in both tumor progression and resistance to antitumor immune responses, possibly through direct and indirect mechanisms. It is known to be expressed in several human malignancies, including esophageal squamous cell carcinoma, follicular lymphoma and melanoma. HVEM network may therefore be an attractive target for drug intervention [, ].TNF-receptors are modular proteins. The N-terminal extracellular part contains a cysteine-rich region responsible for ligand-binding. This region is composed of small modules of about 40 residues containing 6 conserved cysteines; the number and type of modules can vary in different members of the family [, , ].This entry represents the N-terminal domain of TNFRSF14, and is also found in the orphan TNFR, UL144, present in human Cytomegalovirus. UL144 binds BTLA, but not LIGHT, and inhibits T cell proliferation, selectively mimicking the inhibitory cosignaling function of HVEM []. |
