CD40L/CD154/TRAP Protein, Human (P. pastoris, His)

CD40L, also known as CD154 or TRAP protein, functions as a cytokine and serves as a ligand for CD40/TNFRSF5, orchestrating a cascade of immunological responses. It plays a pivotal role in T-cell activation, acting as a potent co-stimulator that enhances both T-cell proliferation and cytokine production, specifically IL4 and IL10. Upon cross-linking on T-cells, CD40L generates a costimulatory signal synergizing with TCR/CD3 ligation and CD28 costimulation. Additionally, CD40L induces the activation of NF-kappa-B, triggers the activation of kinases MAPK8 and PAK2 in T-cells, and facilitates tyrosine phosphorylation of CD28 isoform 3. Beyond T-cell modulation, CD40L mediates B-cell proliferation in the absence of co-stimulus and promotes IgE production in the presence of IL4, contributing to immunoglobulin class switching. Furthermore, it serves as a ligand for integrins, specifically ITGA5:ITGB1 and ITGAV:ITGB3, and collaborates with the CD40 receptor in the activation of CD40-CD40LG signaling, exerting cell-type-dependent effects such as B-cell activation, NF-kappa-B signaling, and anti-apoptotic signaling.