A monoclonal antibody recognizing CD43 (leukosialin) initiates apoptosis of human hematopoietic progenitor cells but not stem cells.

CD43 (the major sialoglycoprotein of leukocytes) is an adhesion molecule broadly expressed on hematopoietic cells. A monoclonal antibody recognizing this molecule induces apoptosis of lineage marker-negative bone marrow hematopoietic progenitor cells (HPCs) that express CD34 at a high density (CD34hiLIN-). However, not all cells within this population undergo apoptosis on stimulation via CD43.