Detects human OX40/TNFRSF4 in direct ELISAs and Western blots. In Western blots, no cross-reactivity with recombinant human (rh) 4-1BB, rhBAFF R, rhCD27, rhCD30, rhCD40, rhDR3, rhDR6, rhEDAR, rhFAS, rhGITR, rhHVEM, rhLT beta R, rhNGF R, rhRANK, rhRELT, rhTAJ, rhTNF RI, rhTNF RII, rhTRAIL, rhTRAIL R4, rhTRAIL R3, rhTWEAK R, or rhXEDAR is observed.
Monoclonal Rat IgG2A Clone # 443318
Protein A or G purified from hybridoma culture supernatant
Mouse myeloma cell line NS0-derived recombinant human OX40/TNFRSF4 Leu29-Ala216 Accession # P43489
Supplied in a saline solution containing BSA and Sodium Azide.
10 µL/106 cells
Please Note: Optimal dilutions should be determined by each laboratory for each application. General Protocols are available in the Technical Information section on our website.
Detection of OX40/TNFRSF4 in Human PBMCs by Flow Cytometry. Human peripheral blood mononuclear cells (PBMCs) were stained with Mouse Anti-Human CD3 PE‑conjugated Monoclonal Antibody (Catalog # FAB100P) and either (A) Rat Anti-Human OX40/TNFRSF4 APC‑conjugated Monoclonal Antibody (Catalog # FAB3388A) or (B) Rat IgG2A Allophycocyanin Isotype Control (Catalog # IC006A). View our protocol for Staining Membrane-associated Proteins.
Preparation and Storage
The product is shipped with polar packs. Upon receipt, store it immediately at the temperature recommended below.
Stability & Storage
Protect from light. Do not freeze.
12 months from date of receipt, 2 to 8 °C as supplied.
OX40 (also known as CD134 and TNFRSF4) is a T cell co‑stimulatory molecule of the TNF receptor superfamily that coordinates with other membrane-bound co‑stimulators such as CD28, CD40, CD30, CD27 and 4-1BB (1‑3). OX40 is expressed on naïve CD4+ T cells only after engagement of the TCR by antigen presenting cells (APC; dendritic and B cells), and co‑stimulation by CD40/CD40 ligand and CD28/B7. It is maximal at 2‑5 days post activation, or 4 hours post reactivation of memory T cells (3‑6). Human OX40 is a 48 kDa type I transmembrane glycoprotein with a 28 amino acid (aa) signal sequence, a 185 aa extracellular domain (ECD) that has four TNFR-Cys repeats and an O-glycosylated hinge region, a 20 aa transmembrane segment, and a 41 aa cytoplasmic domain (3). The ECD of human OX40 shows 71%, 68%, 67%, 64% and 64% aa identity with feline, canine, rabbit, mouse and rat OX40 ECD, respectively. Engagement of OX40 on activated CD4+ T cells by OX40 ligand on activated dendritic cells promotes T cell survival and proliferation, prolongs the immune response, and enhances the number of cells making the transition from effector to memory T cells (1‑6). OX40 signal transduction includes binding TNF receptor-associated factors (TRAFs), and activating NF kappa B and PI3 kinase to enhance expression of cytokines, antiapoptotic Bcl-2 family members, survivin and the chemokine receptor CXCR5 (5‑8). CXCR5 promotes T cell migration to germinal centers to deliver B cell help (5). Studies using knockout or transgenic mice, and agonistic or blocking antibodies, show that OX40/OX40L interaction is critical for establishing or reactivating memory T cells and breaking immune tolerance (9). Blockade of OX40 engagement is efficacious in animal models of allergic airway inflammation, graft-versus-host disease and autoimmune disease (10‑14).
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