Human CD40L

CD40 Ligand is a 33-39 kDa type II transmembrane glycoprotein member of the TNF superfamily, up-regulated after stimulation of basophils, eosinophils, fibroblasts, mast cells, monocytes, natural killer cells, vascular endothelial cells, and smooth muscle cells. CD40 Ligand binds and activates CD40, which is expressed on the surface of B cells, dendritic cells, macrophages, monocytes, platelets, endothelial cells, and epithelial cells. CD40 Ligand dysregulation on T cells and antigen presenting cells contributes to the immune deficiency associated with HIV infection and AIDS and implicated in the pathology of multiple cardiovascular diseases including atherosclerosis, atherothrombosis, and restenosis (1-5).