title: High-level in vivo gene marking after gene-modified autologous hematopoietic stem cell transplantation without marrow conditioning in nonhuman primates.
abstract: The successful engraftment of genetically modified hematopoietic stem cells (HSCs) without toxic conditioning is a desired goal for HSC gene therapy. To this end, we have examined the combination of intrabone marrow transplantation (iBMT) and in vivo expansion by a selective amplifier gene (SAG) in a nonhuman primate model. The SAG is a chimeric gene consisting of the erythropoietin (EPO) receptor gene (as a molecular switch) and c-Mpl gene (as a signal generator). Cynomolgus CD34+ cells were retrovirally transduced with or without SAG and returned into the femur and humerus following irrigation with saline without prior conditioning. After iBMT without SAG, 2-30% of colony-forming cells were gene marked over 1 year. The marking levels in the peripheral blood, however, remained low (<0.1%). These results indicate that transplanted cells can engraft without conditioning after iBMT, but in vivo expansion is limited. On the other hand, after iBMT with SAG, the peripheral marking levels increased more than 20-fold (up to 8-9%) in response to EPO even at 1 year posttransplant. The increase was EPO-dependent, multilineage, polyclonal, and repeatable. Our results suggest that the combination of iBMT and SAG allows efficient in vivo gene transduction without marrow conditioning.
authors.affiliation: Center for Molecular Medicine, Jichi Medical School, Tochigi 329-0498, Japan.
authors.forename: Kyoji
authors.initials: K
authors.lastname: Ueda
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Hanazono
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Shibata
authors.forename: Naohide
authors.initials: N
authors.lastname: Ageyama
authors.forename: Yasuji
authors.initials: Y
authors.lastname: Ueda
authors.forename: Satoko
authors.initials: S
authors.lastname: Ogata
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Tabata
authors.forename: Takeyuki
authors.initials: T
authors.lastname: Nagashima
authors.forename: Masaaki
authors.initials: M
authors.lastname: Takatoku
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kume
authors.forename: Susumu
authors.initials: S
authors.lastname: Ikehara
authors.forename: Masafumi
authors.initials: M
authors.lastname: Taniwaki
authors.forename: Keiji
authors.initials: K
authors.lastname: Terao
authors.forename: Mamoru
authors.initials: M
authors.lastname: Hasegawa
authors.forename: Keiya
authors.initials: K
authors.lastname: Ozawa
mesh_terms: D000818:Animals; D018952:Antigens, CD34 / Q000378:metabolism; D004921:Erythropoietin / Q000494:pharmacology; D015870:Gene Expression; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods*; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000378:metabolism; D008252:Macaca fascicularis; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000378:metabolism; D018121:Receptors, Cytokine / Q000235:genetics* / Q000378:metabolism; D017467:Receptors, Erythropoietin / Q000235:genetics* / Q000378:metabolism; D053628:Receptors, Thrombopoietin; D012190:Retroviridae / Q000235:genetics; D013997:Time Factors; D019172:Transplantation Conditioning
chemical_list: D018952:Antigens, CD34; D011518:Proto-Oncogene Proteins; D018121:Receptors, Cytokine; D017467:Receptors, Erythropoietin; D053628:Receptors, Thrombopoietin; D004921:Erythropoietin; C082218:MPL protein, human