Leukosialin (CD43) (CD43)

Leukosialin, commonly known as CD43, is a heavily glycosylated type I transmembrane sialoglycoprotein primarily expressed on the surface of hematopoietic cells, including T lymphocytes, monocytes, and granulocytes. It plays a multifaceted role in immune function, acting as both a pro-adhesive and anti-adhesive molecule, and is involved in T-cell activation, signal transduction, and the formation of a 'glyco-immune barrier' that helps cancer cells evade immune detection. The UMG1 epitope is a specific, cancer-associated glycoform of CD43 that is highly expressed in various hematological malignancies, such as T-cell acute lymphoblastic leukemia (T-ALL) and diffuse large B-cell lymphoma (DLBCL), while remaining largely absent from normal tissues except for cortical thymocytes. Therapeutic strategies targeting the UMG1 epitope, including humanized monoclonal antibodies and bispecific T-cell engagers, aim to exploit this restricted expression to induce targeted tumor cell lysis via mechanisms like antibody-dependent cellular cytotoxicity (ADCC) and redirected T-cell activity. In addition to its role in leukemia and lymphoma, CD43 has been implicated in the pathogenesis of Wiskott-Aldrich syndrome and various solid tumors. Recent research highlights its function as a physical barrier that prevents macrophage phagocytosis, suggesting that targeting CD43 could synergize with other immunotherapies like CD47 blockade.

Other names

SialophorinSPNGalactoglycoproteinGPL115Leukocyte sialoglycoproteinUN1 antigenUMG1 epitope

Antibody-dependent cellular cytotoxicity (ADCC), antibody-dependent cellular phagocytosis (ADCP), and redirected T-cell-mediated cytotoxicity targeting the UMG1 epitope of CD43.