Storage Instruction:Store the kit at 4°C. Description:
CD40 Ligand (CD40L), also known as CD154, gp39, TNFSF5, TRAP (TNF-Related Activation Protein) or TBAM (T-cell B-cell Activating Molecule), is a multifunctional ligand in the TNF superfamily . Interaction between CD40 and CD40L is critical to the control of thymus-dependent humoral immunity and cell-mediated immune responses . The major component of the contact-dependent signal leading to B cell activation is CD40L. CD40L stimulates B cell secretion of immunoglobulin isotypes in the presence of cytokines. CD40L is a 39 kDa, 261 amino acid (aa) glycoprotein that can form homotrimers typical of other TNFSF members. Proteolytic cleavage can also produce 15 - 18 kDa soluble forms of CD40L. Activated T cells and platelets express both a membrane- associated and a soluble form of CD40L (sCD40L). Platelet activation during plasma and serum sample preparation can result in artificially elevated sCD40L levels . Conversely, serum samples stored above 2 - 8!aC show a progressive loss of th sCD40L signal .