OX40 LIGAND HUMAN

General description

OX40L or tumor necrosis factor superfamily member 4 (TNFSF4), which is a member of the TNF superfamily of structurally related proteins, exists primarily as a type II membrane bound, non-covalently linked homotrimeric protein. This cytokine 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. It has a 23 amino acid cytoplasmic tail and a 133 amino acid extracellular domain. The gene encoding this protein is localized on human chromosome 1q25 and has three exons. Recombinant OX40L 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 15.5-25kDa on SDS-PAGE.

Biochem/physiol Actions

OX40L signals specifically through 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 regulated on activation, normal T cell expressed and secreted (RANTES) or chemokine ligand 5 (CCL5), interleukins-2 and -3, and interferon-γ (IFNγ). OX40/OX40L signaling plays an important role in immuno-regulatory communication and immune-tolerance. Polymorphisms in the TNFSF4 gene have been associated with autoimmune thyroid diseases (AITDs), rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and systemic sclerosis (SSc).

Sequence

QVSHRYPRIQ SIKVQFTEYK KEKGFILTSQ KEDEIMKVQN NSVIINCDGF YLISLKGYFS QEVNISLHYQ KDEEPLFQLK KVRSVNSLMV ASLTYKDKVY LNVTTDNTSL DDFHVNGGEL ILIHQNPGEF CVL

Physical form

Lyophilized from 10 mM Tris pH 8.5.

Reconstitution

Centrifuge the vial prior to opening. Reconstitute in water to a concentration of 0.1-1.0 mg/ml. Do not vortex. This solution can be stored at 2-8°C for up to 1 week. For extended storage, it is recommended to further dilute in a buffer containing a carrier protein (example 0.1% BSA) and store in working aliquots at -20°C to -80°C.