CD40

CD40, also known as TNFRSF5, is a type I transmembrane protein. The molecular weight of CD40 is 48-kDa and it consists of a 193 amino acid (aa) extracellular domain, 21 aa leader sequence, 22 aa transmembrane domain, and a 62 aa intracellular domain in human (90 aa in mouse). There are 22 cysteine residues in the extracellular domain of CD40, and they are conserved between the members of the TNFR superfamily. Primitively, the expression of CD40 was found on B cells, and it is expressed by a variety of other cells, such as dendritic cells (DCs), platelets, monocytes, and macrophages, as well as by non-hematopoietic cells, including epithelial, myofibroblasts, fibroblasts, and endothelial cells.
CD40 serves as an important role in the pathogenesis of inflammation and autoimmunity. Besides, B cell CD40 directly activates cells, which enables to induce autoantibody production. CD154 is the ligand for CD40 and it is expressed on activated T cells and enables interactions with APC during the cognitive phase of the immune response, as well as directing effector T cell-dependent B cell activation. However, it has been reported that blocking CD40-CD154 interactions may either prevent or alleviate diseases, including insulin dependent diabetes mellitus, arthritis, and systemic lupus erythematosus.
Gene ID: 958
UniProt ID: P25942