title: New selective amplifier genes containing c-Mpl for hematopoietic cell expansion.
abstract: We previously developed "selective amplifier genes (SAGs)" which confer a growth advantage to transduced cells. The SAG is a chimeric gene encoding the G-CSF receptor (GCR) and the estrogen or tamoxifen (Tm) receptor and is able to expand transduced hematopoietic cells by treatment with estrogen or Tm. In the current study, we examined the in vitro efficacy of modified SAGs containing the thrombopoietin (TPO) receptor (c-Mpl) gene instead of GCR as a more potent signal generator. In addition, we constructed various mutant Mpl-type SAGs to abolish the responsiveness to endogenous TPO while retaining Tm-dependency. When Ba/F3 cells were retrovirally transduced with the Mpl-type SAGs, the cells showed Tm- and TPO-dependent growth even without IL-3. The Mpl-type SAGs induced more potent proliferation of Ba/F3 and cynomolgus CD34(+) cells than the GCR-type SAG. One mutant Mpl-type SAG (Delta GCRMplTmR) successfully lost the responsiveness to TPO without affecting the Tm-dependence.
authors.affiliation: DNAVEC Research, Incorporated, 1-25-11, Kannondai, Tsukuba-shi, Ibaraki-Ken 305-0856, Japan.
authors.forename: Takeyuki
authors.initials: T
authors.lastname: Nagashima
authors.forename: Yasuji
authors.initials: Y
authors.lastname: Ueda
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Hanazono
authors.forename: Akihiro
authors.initials: A
authors.lastname: Kume
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Shibata
authors.forename: Naohide
authors.initials: N
authors.lastname: Ageyama
authors.forename: Keiji
authors.initials: K
authors.lastname: Terao
authors.forename: Keiya
authors.initials: K
authors.lastname: Ozawa
authors.forename: Mamoru
authors.initials: M
authors.lastname: Hasegawa
mesh_terms: D000818:Animals; D018952:Antigens, CD34 / Q000096:biosynthesis; D001665:Binding Sites; D015153:Blotting, Western; D001854:Bone Marrow Cells / Q000378:metabolism; D002455:Cell Division; D002460:Cell Line; D019281:Dimerization; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D017353:Gene Deletion; D005821:Genetic Techniques; D015316:Genetic Therapy; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006801:Humans; D007377:Interleukin-3 / Q000378:metabolism; D051379:Mice; D009154:Mutation; D009363:Neoplasm Proteins / Q000235:genetics* / Q000378:metabolism*; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000378:metabolism*; D018121:Receptors, Cytokine / Q000235:genetics* / Q000378:metabolism*; D053628:Receptors, Thrombopoietin; D012190:Retroviridae / Q000235:genetics
chemical_list: D018952:Antigens, CD34; D007377:Interleukin-3; D009363:Neoplasm Proteins; D011518:Proto-Oncogene Proteins; D018121:Receptors, Cytokine; D053628:Receptors, Thrombopoietin; C082218:MPL protein, human