Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P10721 (c-kit)
 6,575 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Epitopes on the CD34 molecule detected by some CD34 antibodies can be cleaved by a unique glycoprotease from Pasteurella haemolytica, which cleaves only glycoproteins rich in O-linked glycans. A method to isolate CD34+ cells from adult bone marrow was developed subsequently, in which CD34+ cells were isolated in high purity and yield following immunomagnetic bead selection and detachment with the glycoprotease. Using a variety of other cell-surface markers shown here to be insensitive to glycoprotease, committed progenitors of T lymphoid, B lymphoid, monomyeloid, megakaryoblastic, or erythroid lineages could be identified. Significantly, candidate hematopoietic stem cells (HSC) that are contained within a CD34+Lin- (CD2-, CD14-, CD15-, CD16-, CD19-) (or CD34+CD38-) subset expressing the Thy-1 antigen (CDw90), c-kit receptor (CD117), and CDw109 but lacking expression of CD71 and HLA-DR antigens also were detected. Functionally distinct subsets of glycoprotease-selected CD34+ cells were identified and subfractionated using flow cytometry and fluorescence-activated cell sorting (FACS). These subsets included candidate HSCs expressing the CD34+Thy-1+Lin- phenotype, which were sorted from a CD34+ fraction of a mobilized peripheral blood (MPB) sample. In a fetal sheep model, when CD34+Thy-1+Lin- cells were injected intraperitoneally, they were capable of homing to the marrow, where they generated long-term multilineage hematopoiesis and maintained human CD34+ cells, indicating that candidate HSC subsets of CD34+ cells selected with this highly specific enzyme were capable of engraftment in vivo. The ability to identify and purify virtually any phenotypically defined subset of glycoprotease-selected CD34+ stem/progenitor cells should facilitate the study of hematopoiesis in vitro and in animal models in vivo as well as the development of novel genetic techniques for the correction of specific blood cell disorders in humans.
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PMID:Identification of CD34+ subsets after glycoprotease selection: engraftment of CD34+Thy-1+Lin- stem cells in fetal sheep. 864 30

Haemopoietic progenitor cells (HPCs) express the CD34 molecule, a heavily glycosylated transmembrane protein displaying three main classes of epitopes. The CD34 epitope class expression may vary between different subsets of HPCs. The aim of this study was to characterise the subsets of HPCs expressing CD34 class II and III epitopes. The cells were studied for coexpression of activation-, lineage- and adhesion-associated molecules, and their clonogenic ability and morphological features were examined. CD34+ HPCs expressing class III epitopes outnumbered those expressing class II. Class III expressing HPCs were enriched for CFU-GM and BFU-E and cells coexpressing CD13, CD33, c-kit and CD71 compared to class II expressing HPCs. CD34+ cells exclusively expressing class III epitopes uniformly displayed CD13 and CD33; they had a high clonogenic capacity and morphological characteristics of promyelocytes and myelocytes. The data show that class III epitopes are distributed more broadly on CD34+ HPCs than are class II epitopes, and that lack of class II epitopes is confined to CD34+ HPCs at a late stage of myeloid differentiation. The higher number of class III expressing HPCs coexpressing c-kit and CD71 suggests that these cells exhibit a higher proliferative or differential potential than do HPCs expressing class II epitopes.
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PMID:Characteristics of haemopoietic progenitor cells related to CD34 epitope class expression. 1077 96