CD154 iFluor 488

The clone 5C8, a mouse monoclonal antibody, specifically recognizes a ~30-33 kDa activation-induced human CD4+ T cells surface molecule known as CD154 or CD40 ligand (CD40L). The CD40 interacts with CD154 through T cell-B cell activating molecule, gp39, TNF cytokine related activation protein. CD154 is primarily expressed on the surface of activated CD4+ T cells but can also be expressed by platelets, mast cells, macrophages, basophils, NK cells, B cells, CD8+ T cells as well as non-hematopoietic cells including smooth muscle cells, endothelial cells, and epithelial cells. CD154 plays important roles in the pathogenesis of certain blood cancer such as the CD4+ T cells of patients with CLL fail to express surface CD154 antigen even after CD3 ligation, and proximal and distal activation events are required for the neonatal CD4+ T cells for the CD154 gene transcription to establish the normal immune system.