title: Potent inhibition of simian immunodeficiency virus (SIV) replication by an SIV-based lentiviral vector expressing antisense Env.
abstract: In light of findings demonstrating that the macaque TRIM5alpha protein inhibits infection of cells by human immunodeficiency virus (HIV)-1, simian immunodeficiency virus (SIV)-based lentiviral vectors may have distinct advantages over HIV-1 vectors for the transduction of macaque hematopoietic stem cells. We evaluated the ability of an SIV vector (VRX859) encoding an antisense SIV envelope sequence and enhanced green fluorescent protein (GFP) to inhibit viral replication and to transduce rhesus CD34(+) lymphoid progenitor cells. After infection with homologous SIV strains, CD4(+) cell lines transduced with VRX859 exhibited more than 600-fold inhibition of viral replication compared with control cells. Less inhibition was observed with the divergent SIV strain SIVsmE660. Partial inhibition of a chimeric simian-human immunodeficiency virus, which contains an HIV-1 envelope in an SIV backbone, was observed, suggesting that the SIV vector also contributes to viral inhibition independent of the antisense envelope inhibitor. Transduction of rhesus CD34(+) cells with VRX859 at various multiplicities of infection resulted in transduction efficiencies comparable to those obtained with the HIV vector VRX494. However, when we evaluated transduction of rhesus T lymphocyte progenitors by examining GFP expression in CD4(+) T cells derived from transduced CD34(+) cells, we observed more efficient transduction with the SIV-based vector. GFP(+)CD4(+) T cells derived from VRX859-transduced CD34(+) cells strongly inhibited SIVmac239 replication as compared with control CD4(+) T cells. The ability of this SIV-based vector to mediate potent inhibition of SIV replication, coupled with its efficient transduction of rhesus hematopoietic progenitor cells, make it an important candidate for proof-of-principle experiments of stem cell gene therapy in the SIV-macaque model.
authors.affiliation: Division of Immunology, New England Primate Research Center, Harvard Medical School, Southborough, MA 01772, USA. stephen_braun@hms.harvard.edu
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Braun
authors.forename: Xiaobin V
authors.initials: XV
authors.lastname: Lu
authors.forename: Fay Eng
authors.initials: FE
authors.lastname: Wong
authors.forename: Michelle
authors.initials: M
authors.lastname: Connole
authors.forename: Gang
authors.initials: G
authors.lastname: Qiu
authors.forename: Ziping
authors.initials: Z
authors.lastname: Chen
authors.forename: Tatiana
authors.initials: T
authors.lastname: Slepushkina
authors.forename: Vladimir
authors.initials: V
authors.lastname: Slepushkin
authors.forename: Laurent M
authors.initials: LM
authors.lastname: Humeau
authors.forename: Boro
authors.initials: B
authors.lastname: Dropulic
authors.forename: R Paul
authors.initials: RP
authors.lastname: Johnson
mesh_terms: D000818:Animals; D018952:Antigens, CD34 / Q000378:metabolism; D002460:Cell Line; D002478:Cells, Cultured; D005434:Flow Cytometry; D005456:Fluorescent Dyes / Q000378:metabolism; D015752:Genes, env / Q000235:genetics; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006412:Hematopoietic Stem Cells / Q000378:metabolism; D006801:Humans; D016086:Lentivirus / Q000235:genetics*; D016376:Oligonucleotides, Antisense / Q000494:pharmacology*; D015302:Simian Immunodeficiency Virus / Q000235:genetics*; D013601:T-Lymphocytes / Q000378:metabolism; D014161:Transduction, Genetic; D014779:Virus Replication / Q000187:drug effects*
chemical_list: D018952:Antigens, CD34; D005456:Fluorescent Dyes; D016376:Oligonucleotides, Antisense; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins