Cytokine that acts as a ligand to CD40/TNFRSF5 (, ). 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 . Induces the activation of NF-kappa-B (, ). Induces the activation of kinases MAPK8 and PAK2 in T-cells . Induces tyrosine phosphorylation of isoform 3 of CD28 . Mediates B-cell proliferation in the absence of co-stimulus as well as IgE production in the presence of IL4 (By similarity). Involved in immunoglobulin class switching (By similarity).
Acts as a ligand for integrins, specifically ITGA5:ITGB1 and ITGAV:ITGB3; both integrins and the CD40 receptor are required for activation of CD40-CD40LG signaling, which have cell-type dependent effects, such as B-cell activation, NF-kappa-B signaling and anti-apoptotic signaling.
Subcellular locations: Cell membrane, Cell surface
Subcellular locations: Secreted
Release of soluble CD40L from platelets is partially regulated by GP IIb/IIIa, actin polymerization, and a matrix metalloproteinases (MMP) inhibitor-sensitive pathway.
Specifically expressed on activated CD4+ T-lymphocytes.