Human CD154 (CD40L) Antibody from BIOLEGEND

CD40L is a type II membrane protein that shares 78% amino acid identity with its mouse counterpart. Human CD40L is a polypeptide of 261 amino acids, consisting of 22, 24, and 215 amino acids for the cytoplasmic, transmembrane, and extracellular domains respectively. Soluble forms of CD40L (sCD40L) have been identified, and an 18 kD fragment has the ability to form homotrimers and bind to CD40 to induce biological signals. The 18 kD protein has full activity in B cell proliferation and differentiation assays. Activated platelets express CD40L on their surface and constitute the major source of sCD40L (>95% in blood). Platelet-derived CD40L regulates neutrophil recruitment and lung damage in sepsis, and it has been suggested that MMP9 regulates CD40L shedding in abdominal sepsis. Platelet-associated CD40L has been linked to progression of atherosclerotic disease, and elevated plasma levels of sCD40L in patients seems to be a reliable predictor of cardiovascular events, such as atherosclerotic plaque rupture and acute coronary syndromes. Also, platelet-associated CD40L expression is increased in idiopathic thrombocytopenic purpura patients, and it has been speculated that platelet-associated-CD40L drives the activation of autoreactive B lymphocytes in this disease. In addition, high plasma levels of sCD40L have been connected to HIV-Associated Neurocognitive Disorders (HAND).