Alexa Fluor^® 488 Rabbit Anti-Human CD43 Antibody (S-R101)

CD43, also known as Leukosialin or Sialophorin, is a type I transmembrane glycoprotein that is highly expressed on the surface of leukocytes (such as T cells, monocytes, and granulocytes) but is absent on resting naive B cells and erythrocytes. Structurally, it features a unique, negatively charged, rigid rod-like extracellular domain heavily modified by approximately 80 O-glycans, along with a cytoplasmic tail containing potential phosphorylation sites that can interact with cytoskeletal linker proteins (such as ERM family members). Functionally, CD43 plays a dual role as both an "anti-adhesion" molecule and a signaling regulator: its bulky extracellular domain serves as a physical barrier that negatively regulates integrin- and L-selectin-mediated cell adhesion and homing through steric hindrance, while its cytoplasmic domain transmits signals to finely regulate T cell activation, proliferation, apoptosis, and the contraction of immune responses. Furthermore, dysregulation of CD43 is closely associated with disease—it is defective or absent in patients with Wiskott-Aldrich syndrome. In various cancer cells, such as acute myeloid leukemia, highly expressed CD43 and its surface sialylated glycosylation modifications form a "glyco-immune barrier" that physically impedes contact between immune effector cells (including macrophages and NK cells) and tumor cells, thereby helping cancer cells achieve immune evasion. Given its central role in immune regulation and tumor immune escape, CD43 has emerged as a highly promising novel target for cancer immunotherapy.