Recombinant Human sOX40 Ligand

OX40L, a member of the TNF superfamily of structurally related proteins, exists primarily as a type II membrane bound, non-covalently linked homotrimeric protein. It is expressed on antigen presenting cells (APCs), such as dendritic cells and activated B cells, and also on various other cells such as vascular endothelial cells, mast cells, and natural killer cells. OX40L signals specifically thro μgh the OX40 receptor, which is expressed predominantly on CD4+T cells but also on certain activated CD8+T cells. OX40/OX40L functions as a costimulatory signal, which is required for a productive interaction between antigen presenting cells and their target T cells. It enhances cell proliferation and survival, and increases expression of RANTES, IL-2, IL-3, and IFNγ. OX40/OX40L signaling plays an important role in immuno-regulatory communication, enabling the immune system to distinguish between “friend vs. foe” during activation; a mechanism typically termed immuno-tolerance. Recombinant Human sOX40 Ligand is a glycosylated 133 amino acid protein corresponding to the extracellular TNF homologous domain of the full length transmembrane protein. It migrates with an apparent molecular mass of 15.5 – 25.0 kDa on SDS-PAGE.