CD34 Monoclonal Antibody (4H11), Alexa Fluor™ 700, eBioscience™, Invitrogen™

Description

• The 4H11 MAb reacts with human CD34, also known as mucosialin
• CD34 belongs to a protein family which also includes endoglycan and podocalyxin
• Members of this family are single pass transmembrane proteins with a heavily glycosylated extracellular and N-terminal mucin domain
• CD34 was first identified as an antigen expressed on hematopoietic progenitors, and has since been extensively used as a marker to isolate cells capable of hematopoietic cell engraftment
• In spite of this, the function of CD34 remains unresolved
• In addition to expression on hematopoietic progenitors, CD34 is expressed on some populations of mesenchymal stem cells, tumor cell lines, and by vascular endothelia in the adult
• Epitopes of CD34 have been assigned to three classes (class I, II or III) based on their differential sensitivity to enzymatic cleavage by neuraminidase, chymopapain, or O-glycoprotease
• According to this analysis, the 4H11 antibody belongs to class III, indicating that it reacts with a protein epitope
• CD34 is a highly glycosylated monomeric with a molecular weight range of 111-115 kDa surface protein that is present on many stem cell populations
• CD34 is a stem cell marker although its expression on human hematopoietic stem cells is reversible
• CD34 may serve as a surface receptor that undergoes receptor-mediated endocytosis and regulates adhesion, differentiation and proliferation of hematopoietic stem cells and other progenitors
• CD34 expression is likely to represent a specific state of hematopoietic development that may have altered adhering properties with expanding and differentiating capabilities in both in vitro and in vivo conditions
• CD34 is possibly an adhesion molecule with a putative role for mediating the attachment of stem cells to the bone marrow extracellular matrix or directly to stromal cells
• Further, CD34 could act as a scaffold for the attachment of lineage specific glycans, allowing stem cells to bind to lectins expressed by stromal cells or other marrow components
• CD34 is thought to have a role in presenting carbohydrate ligands to selectins
• The intracellular chain of the CD34 antigen is a site of phosphorylation by activated protein kinase C suggesting a putative role in signal transduction
• Diseases associated with CD34 dysfunction include dermatofibrosarcoma and neurofibroma.