Hematopoietic progenitor cell antigen CD34 (CD34) (CD34)

Hematopoietic progenitor cell antigen CD34 (CD34) is a transmembrane phosphoglycoprotein primarily expressed on hematopoietic stem and progenitor cells (HSPCs) and vascular endothelial cells [3, 6]. It functions as a cell-cell adhesion molecule and a ligand for L-selectin, facilitating the homing of stem cells to the bone marrow and sites of inflammation [2, 13]. In clinical practice, CD34 is the gold-standard biomarker for identifying and isolating stem cells for hematopoietic stem cell transplantation (HSCT) [6, 14]. Beyond its role as a marker, CD34 is a therapeutic target for cell-based therapies aimed at treating ischemic diseases, such as refractory angina and critical limb ischemia, by promoting neovascularization [8, 15]. It also serves as the primary substrate for ex vivo gene therapy, where CD34+ cells are harvested, genetically modified, and re-infused into patients with genetic disorders like SCID or Wiskott-Aldrich syndrome [17, 18]. While systemic targeting of CD34 is limited by its expression on essential stem cell populations and the vasculature, its utility in cell processing and regenerative medicine remains foundational to modern hematology and oncology [7, 16]. Therapeutic strategies often involve the use of anti-CD34 antibodies for magnetic cell separation or small molecules to expand CD34+ populations ex vivo [4, 14].

Other names

CD34 moleculeMucosialinHematopoietic progenitor cell antigen CD34Cluster of differentiation 34

Cell enrichment and selection via magnetic separation [14], ex vivo expansion of hematopoietic stem cells [4, 18], and pro-angiogenic stimulation for tissue repair [13, 15].