title: A potential molecular approach to ex vivo hematopoietic expansion with recombinant epidermal growth factor receptor-expressing adenovirus vector.
abstract: Ex vivo expansion of hematopoietic stem cell (HSC) is an attractive technology for its potency of a variety of clinical applications. Such a technology has been achieved to some extent with combinations of various cytokines or continuous perfusion cultures. However, much more improvement is required especially for expansion of primitive hematopoietic progenitors. We propose here a novel molecular approach that might have the potential to compensate the current expansion. We designed an adenovirus vector to transiently express human epidermal growth factor receptor (EGFR), which is known to transduce only a mitogenic, but not a differentiation signal to mouse bone marrow cells on human purified CD34+ peripheral blood (PB) cells, and tried to expand these cells with EGF ex vivo. Because we found that exposure of CD34+ PB cells to cytokines induced surface expression of adenovirus-internalization receptor and rendered these cells permissive to adenovirus infection, we infected these cells with the adenovirus vector carrying EGFR gene in the presence of cytokines. Two-color flow cytometric analysis demonstrated that 60.3% +/- 22.4% of CD34+ cells expressed the adenovirus-mediated EGFR. Moreover, long-term culture-initiating cell assay showed that adenovirus vector could transduce more primitive progenitors. Subsequently, we tried to expand these cells in suspension culture with EGF for 5 days. Methylcellulose clonal assay showed that EGF induced 5.0- +/- 2.4-fold proliferation of the colony-forming unit pool during 5 days of expansion. The simple procedure of efficient adenovirus gene delivery to immature hematopoietic cells proved promising, and this technique was potentially applicable for a novel strategy aiming at ex vivo expansion of hematopoietic progenitors.
authors.affiliation: The Third Department of Internal Medicine, Faculty of Medicine, University of Tokyo, Bunkyo-ku, Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Takahashi
authors.forename: K
authors.initials: K
authors.lastname: Yamada
authors.forename: T
authors.initials: T
authors.lastname: Tanaka
authors.forename: K
authors.initials: K
authors.lastname: Kumano
authors.forename: M
authors.initials: M
authors.lastname: Kurokawa
authors.forename: N
authors.initials: N
authors.lastname: Hirano
authors.forename: H
authors.initials: H
authors.lastname: Honda
authors.forename: S
authors.initials: S
authors.lastname: Chiba
authors.forename: K
authors.initials: K
authors.lastname: Tsuji
authors.forename: Y
authors.initials: Y
authors.lastname: Yazaki
authors.forename: T
authors.initials: T
authors.lastname: Nakahata
authors.forename: H
authors.initials: H
authors.lastname: Hirai
mesh_terms: D000256:Adenoviridae; D000818:Animals; D018952:Antigens, CD34; D002455:Cell Division / Q000187:drug effects / Q000235:genetics; D004815:Epidermal Growth Factor / Q000494:pharmacology; D066246:ErbB Receptors / Q000819:agonists / Q000096:biosynthesis* / Q000235:genetics; D005434:Flow Cytometry; D005822:Genetic Vectors; D019650:Hematopoietic Stem Cell Mobilization / Q000379:methods*; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000378:metabolism* / Q000473:pathology*; D006801:Humans; D051379:Mice; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics
chemical_list: D018952:Antigens, CD34; D011994:Recombinant Proteins; D004815:Epidermal Growth Factor; D066246:ErbB Receptors