Anti-CD40L (human), clone hu5c8 (rec.) (blocking) (preservative free)

CD40 Ligand (CD40L), renamed TNFSF5 but now also known as CD154, TRAP and gp39, is a 34-39kDa type II transmembrane glycoprotein, that belongs to the TNF superfamily, and a surface receptor expressed on activated T cells which acts as a costimulatory molecule to trigger immune responses. CD40L binds to CD40, which is essential in mediating a broad variety of immune and inflammatory responses including T cell-dependent immunoglobulin class switching, memory B cell development and germinal center formation. CD40 is constitutively expressed by antigen presenting cells, including dendritic cells, B cells and macrophages. Consistent with its widespread expression on normal cells, CD40 is also expressed on a wide range of tumor cells. CD40L levels are increased in serum and in inflamed tissues of patients with autoimmune diseases. Protein function: Cytokine that binds to CD40/TNFRSF5 (PubMed:1280226). Costimulates T-cell proliferation and cytokine production. Its cross-linking on T-cells generates a costimulatory signal which enhances the production of IL4 and IL10 in conjunction with the TCR/CD3 ligation and CD28 costimulation (PubMed:8617933). Induces the activation of NF-kappa-B and kinases MAPK8 and PAK2 in T- cells. Induces tyrosine phosphorylation of isoform 3 of CD28 (PubMed:15067037). Mediates B-cell proliferation in the absence of co-stimulus as well as IgE production in the presence of IL4. Involved in immunoglobulin class switching. [The UniProt Consortium]