Zebrafish Cluster of Differentiation 40 Ligand / TNFSF5 (CD40LG) Protein

Background

CD40 ligand (CD40LG), also known as CD154 or TNFSF5, is a transmembrane protein expressed primarily on the surface of activated T cells and, to a lesser extent, on platelets and other cell types. It is a key member of the tumor necrosis factor (TNF) superfamily and functions as a ligand for CD40, a receptor found on the surface of various immune cells, including B cells, dendritic cells, macrophages, and endothelial cells. CD40LG-CD40 interactions are essential for effective immune responses, promoting T-cell-B-cell cooperation, antigen presentation, and the production of antibodies. Mutations in CD40LG are linked to X-linked hyper-IgM syndrome (XHIM), a primary immunodeficiency disorder, highlighting the protein's importance in immune system regulation. The CD40LG-CD40 axis also plays a role in the development of autoimmune diseases, cardiovascular disorders, and cancer, where the interaction is implicated in chronic inflammation and pathological immune activation.