title: Mimicking the haematopoietic niche microenvironment provides a novel strategy for expansion of haematopoietic and megakaryocyte-progenitor cells from cord blood.
abstract: Severe neutropenia and protracted thrombocytopenia remain serious clinical problems following cord blood transplantation (CBT) due to the paucity of stem and progenitor cells in the grafts. Administration of ex-vivo expanded megakaryocyte progenitor cells may facilitate platelet production. We propose a novel strategy to expand these rare cells ex-vivo, from a small portion of the cord blood (CB) unit, using fibronectin (FN), a major component of hematopoietic niches, combined with cytokines, including thrombopoietin and the hematopoietic stress-associated acetylcholinesterase readthrough peptide (ARP). Application of multiple gates and high definition flow cytometry enabled clear resolution of expanded hematopoietic stem/precursor cells (HSPC) and megakaryocyte progenitors (Mk-p) and their early subsets while eliminating positively stained non-relevant cells. FN increased viability, expansion of all CD34(+) HSPC populations and Mk-p. The combination of FN + thrombopoietin + ARP maintained and expanded very early myeloid and thrombopoietic precursors, increased the proliferation of megakaryocyte, granulocyte-macrophage and multilineage colony-forming progenitors and supported Mk maturation as measured by ploidy and glycoprotein IIb/IIIa expression by quantiative reverse transcription polymerase chain reaction. This approach, which involves expanding HSPC and Mk precursors from a small portion of the CB unit, without sacrificing the coveted stem cells, may lead to improved cell therapy modalities to facilitate earlier myelopoiesis and platelet production post-CBT.
authors.affiliation: Department of Haematology and Bone Marrow Transplant, Tel Aviv Medical Centre, Tel Aviv University, Israel. Varda@tasmc.health.gov.il <Varda@tasmc.health.gov.il>
authors.forename: Varda
authors.initials: V
authors.lastname: Deutsch
authors.forename: Einav
authors.initials: E
authors.lastname: Hubel
authors.forename: Sigi
authors.initials: S
authors.lastname: Kay
authors.forename: Tal
authors.initials: T
authors.lastname: Ohayon
authors.forename: Ben-Zion
authors.initials: BZ
authors.lastname: Katz
authors.forename: Ariel
authors.initials: A
authors.lastname: Many
authors.forename: Axel
authors.initials: A
authors.lastname: Zander
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Naparstek
authors.forename: Dan
authors.initials: D
authors.lastname: Grisaru
mesh_terms: D000110:Acetylcholinesterase / Q000494:pharmacology; D018952:Antigens, CD34 / Q000032:analysis; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D016207:Cytokines / Q000494:pharmacology; D005312:Fetal Blood / Q000166:cytology*; D005353:Fibronectins / Q000494:pharmacology; D005434:Flow Cytometry / Q000379:methods; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects; D006801:Humans; D055016:Megakaryocyte Progenitor Cells / Q000166:cytology* / Q000187:drug effects; D010446:Peptide Fragments / Q000494:pharmacology
chemical_list: D018952:Antigens, CD34; D016207:Cytokines; D005353:Fibronectins; D010446:Peptide Fragments; D000110:Acetylcholinesterase