title: Expression from second-generation feline immunodeficiency virus vectors is impaired in human hematopoietic cells.
abstract: Vectors based on the feline immunodeficiency virus (FIV) have been developed as an alternative to those based on another lentivirus, human immunodeficiency virus-1 (HIV-1), because of theoretical safety advantages. We compared the efficiency of gene transfer and expression in human and feline hematopoietic progenitors using second-generation HIV-1 and FIV-based vectors. Vector pairs were tested using either human cytomegalovirus or murine phospho-glycerate kinase (PGK) internal promoters and were pseudotyped with the vesicular stomatitis virus G protein (VSV-G). Vector proviral copy numbers were similar in human and feline hematopoietic primary cells and cell lines transduced by HIV-1 or FIV vectors, demonstrating that both vectors are able to transfer genes efficiently to these cell types. HIV-1 vectors were well expressed in human primary hematopoietic cells and cell lines. However, transgene expression from FIV vectors was almost undetectable in human hematopoietic cells. In contrast, the FIV vector was expressed well in primary hematopoietic feline cells and human non-hematopoietic cells, demonstrating that low transgene expression from the FIV vector is a phenomenon specific to human hematopoietic cells. Northern blot analysis demonstrated decreased vector transcript levels in human CEM cells transduced with FIV relative to cells transduced with HIV-1, despite high vector copy numbers. No evidence of vector transcript instability was seen in studies of transduced CEM cells treated with actinomycin D. We conclude that FIV vectors can transfer genes into human hematopoietic cells as effectively as HIV-1 vectors, but that unknown elements in the current FIV backbone inhibit expression from FIV vectors in human hematopoietic cells.
authors.affiliation: Division of Research Immunology/Bone Marrow Transplantation, Childrens Hospital Los Angeles, Los Angeles, California 90027, USA.
authors.forename: Mary A
authors.initials: MA
authors.lastname: Price
authors.forename: Scott S
authors.initials: SS
authors.lastname: Case
authors.forename: Denise A
authors.initials: DA
authors.lastname: Carbonaro
authors.forename: Xiao-Jin
authors.initials: XJ
authors.lastname: Yu
authors.forename: Denise
authors.initials: D
authors.lastname: Petersen
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Sabo
authors.forename: Michael A
authors.initials: MA
authors.lastname: Curran
authors.forename: Barbara C
authors.initials: BC
authors.lastname: Engel
authors.forename: Hovanes
authors.initials: H
authors.lastname: Margarian
authors.forename: Janis L
authors.initials: JL
authors.lastname: Abkowitz
authors.forename: Garry P
authors.initials: GP
authors.lastname: Nolan
authors.forename: Donald B
authors.initials: DB
authors.lastname: Kohn
authors.forename: Gay M
authors.initials: GM
authors.lastname: Crooks
mesh_terms: D018952:Antigens, CD34 / Q000096:biosynthesis; D015152:Blotting, Northern; D001854:Bone Marrow Cells / Q000166:cytology; D003587:Cytomegalovirus / Q000235:genetics; D005312:Fetal Blood / Q000378:metabolism; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins; D015497:HIV-1 / Q000235:genetics; D006412:Hematopoietic Stem Cells / Q000378:metabolism*; D006801:Humans; D016089:Immunodeficiency Virus, Feline / Q000235:genetics*; D016086:Lentivirus / Q000235:genetics; D008164:Luminescent Proteins / Q000378:metabolism; D010735:Phosphoglycerate Kinase / Q000235:genetics; D012313:RNA / Q000378:metabolism; D013997:Time Factors; D019076:Transgenes
chemical_list: D018952:Antigens, CD34; D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins; D012313:RNA; D010735:Phosphoglycerate Kinase