title: Ex vivo selection and expansion of cells based on expression of a mutated inosine monophosphate dehydrogenase 2 after HIV vector transduction: effects on lymphocytes, monocytes, and CD34+ stem cells.
abstract: Hematopoietic progenitor cells (HPCs) represent an ideal target for gene therapy treatment of human immunodeficiency virus (HIV) infection. However, gene delivery into quiescent HPCs by retroviral or lentiviral vectors remains relatively poor. We evaluated a selection scheme based on the expression of a variant of inosine monophosphate dehydrogenase 2 (IMPDH2), the rate-limiting enzyme in the de novo purine biosynthesis pathway. As lymphocytes depend more than other cell types on de novo synthesis of purines, IMPDH inhibitors such as mycophenolic acid (MPA) can selectively expand lymphocytes overexpressing the enzymes. We used HIV vectors to deliver an IMPDH variant into T cells and HPCs. We showed that the transduced T cells became resistant to MPA selection. By expressing a short hairpin RNA gene targeted to the HIV gag transcript, the MPA-selected T cells became resistant to HIV-1 infection. Monocyte/macrophages derived from the transduced HPCs differentiated normally and exhibited normal function as measured by B7 up-regulation and phagocytosis when stimulated. Our results suggest that this system may be applicable as a selection strategy to enrich transduced T lymphocytes and mononuclear cells in vivo for HIV gene therapy.
authors.affiliation: Division of Virology, Beckman Research Institute, City of Hope National Medical Center, Duarte, CA 91010, USA. pyam@coh.org
authors.forename: Priscilla
authors.initials: P
authors.lastname: Yam
authors.forename: Michael
authors.initials: M
authors.lastname: Jensen
authors.forename: Ramesh
authors.initials: R
authors.lastname: Akkina
authors.forename: Joseph
authors.initials: J
authors.lastname: Anderson
authors.forename: Maria C
authors.initials: MC
authors.lastname: Villacres
authors.forename: Jerry
authors.initials: J
authors.lastname: Wu
authors.forename: John A
authors.initials: JA
authors.lastname: Zaia
authors.forename: Jiing-Kuan
authors.initials: JK
authors.lastname: Yee
mesh_terms: D000818:Animals; D018952:Antigens, CD34; D018122:B7-1 Antigen / Q000096:biosynthesis; D002454:Cell Differentiation; D002460:Cell Line; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis; D004351:Drug Resistance; D005312:Fetal Blood / Q000166:cytology; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins; D016655:HIV Core Protein p24 / Q000235:genetics / Q000378:metabolism; D015497:HIV-1 / Q000235:genetics* / Q000502:physiology; D006412:Hematopoietic Stem Cells / Q000166:cytology; D006801:Humans; D007168:IMP Dehydrogenase / Q000235:genetics*; D008264:Macrophages / Q000276:immunology; D009000:Monocytes / Q000166:cytology; D009154:Mutation; D009173:Mycophenolic Acid / Q000494:pharmacology; D010587:Phagocytosis; D034741:RNA, Small Interfering; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D014161:Transduction, Genetic; D015854:Up-Regulation; D014779:Virus Replication
chemical_list: D018952:Antigens, CD34; D018122:B7-1 Antigen; D016207:Cytokines; D016655:HIV Core Protein p24; D034741:RNA, Small Interfering; D049452:Green Fluorescent Proteins; D007168:IMP Dehydrogenase; C501687:IMPDH2 protein, human; D009173:Mycophenolic Acid