title: CD34+ positive haemopoietic cells: biology and clinical applications.
abstract: CD34+ is a heavily glycosylated surface antigen which is preferentially expressed on haemopoietic stem/progenitor cells. No definitive function has been attributed to CD34+, but it appears to play a role in cell to cell adhesion and may be involved in signal transduction to regulate the expression of other haemopoiesis-associated genes. A number of monoclonal antibodies to CD34+ have been raised and these have allowed the identification and characterization of a whole range of haemopoietic progenitor cells. CD34+ is expressed most strongly on the most primitive cells and is progressively lost as cells differentiate. The restricted expression of CD34+ to haemopoietic stem/progenitor cells has been exploited for transplantation studies. Several techniques have been developed to select cells expressing CD34+ from haemopoietic tissues. Successful sustained engraftment can be achieved using such positively selected cells. Alternatively, CD34+ cells may be expanded in vitro by incubation with synergistic cytokine combinations before being re-infused. An exciting new development has been the use of purified populations of CD34+ cells as the targets for gene marking and gene therapy protocols.
authors.affiliation: Department of Haematology, Glasgow Royal Infirmary, UK.
authors.forename: T L
authors.initials: TL
authors.lastname: Holyoake
authors.forename: M J
authors.initials: MJ
authors.lastname: Alcorn
mesh_terms: D015703:Antigens, CD / Q000097:blood*; D018952:Antigens, CD34; D016465:Bone Marrow Purging; D016026:Bone Marrow Transplantation; D015316:Genetic Therapy; D006412:Hematopoietic Stem Cells / Q000276:immunology*; D006801:Humans; D007938:Leukemia / Q000276:immunology / Q000628:therapy
chemical_list: D015703:Antigens, CD; D018952:Antigens, CD34