TL1A (soluble) (mouse), (recombinant)

TL1A (TNFSF15), a ligand belonging to the tumor necrosis factor (TNF) family, is expressed predominantly by endothelial cells and monocytes. TL1a is upregulated by the proinflammatory cytokines TNF and IL-1 and also by immune complexes (IC). TL1 functions in T cell costimulation and Th1 polarization. On activated T cells, TL1A functions specifically via its surface-bound receptor DR3, (a member of the death-domain containing TNF receptor family) to promote cell survival and secretion of proinflammatory cytokines. The secreted decoy receptor 3 (DcR3), a soluble protein of the tumor necrosis factor receptor (TNFR) superfamily blocks the action of TL1A. TL1A can be released to circulate as a homotrimeric soluble form. Activation of DR3 by TL1A induced the formation of a signaling complex containing TRADD, TRAF2, and RIP and activated the NF-κB and the ERK, JNK, and p38 mitogen-activated protein kinase pathways. The TL1A/DR3 pathway plays an important role in Th1-mediated intestinal diseases, such as Crohn’s disease.