title: Development and testing of retroviral vectors expressing multimeric hammerhead ribozymes targeted against all major clades of HIV-1.
abstract: Rz1-9 is a multimeric hammerhead ribozyme targeted against nine highly conserved sites within the env coding region of human immunodeficiency virus type-1 (HIV-1) RNA. This ribozyme was shown to inhibit HIV-1 replication (1, 2). However, Rz1-9 target sites are only conserved within the clade B of HIV-1. In this study, we have designed another multimeric ribozyme, Rz10-14. This multimeric ribozyme is targeted against five sites that are highly conserved amongst all major clades of HIV-1. A third multimeric ribozyme, Rz1-14, was obtained by combining both Rz1-9 and Rz10-14. A mouse stem cell virus-based MGIN vector (3) was used to express these ribozymes in a human CD4+ T lymphoid cell line. Stable transductants expressed vector RNA containing ribozymes which were shown to be active. In HIV-1 challenge experiments, very little or no virus production could be detected in the pools of stable MT4 transductants expressing Rz1-14 for 60 days tested. Inhibition of virus replication was most prominent with Rz1-14, followed by Rz1-9, and then Rz10-14. Thus, the combined multimeric ribozyme, Rz1-14, is more effective than Rz1-9 or Rz10-14. As Rz1-14 is targeted against all major clades of HIV-1, it will be further pursued for use in HIV-1 gene therapy.
authors.affiliation: Department of Medical Genetics and Microbiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 3E2, Canada.
authors.forename: Ali
authors.initials: A
authors.lastname: Ramezani
authors.forename: Xue Zhong
authors.initials: XZ
authors.lastname: Ma
authors.forename: Reza
authors.initials: R
authors.lastname: Nazari
authors.forename: Sadhna
authors.initials: S
authors.lastname: Joshi
mesh_terms: D015496:CD4-Positive T-Lymphocytes / Q000821:virology; D002460:Cell Line; D018390:Gene Targeting; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D015658:HIV Infections / Q000628:therapy; D015497:HIV-1 / Q000235:genetics / Q000254:growth & development; D006801:Humans; D016337:RNA, Catalytic / Q000235:genetics* / Q000378:metabolism; D012190:Retroviridae / Q000235:genetics*; D013045:Species Specificity; D014161:Transduction, Genetic; D014779:Virus Replication
chemical_list: D016337:RNA, Catalytic; C427204:hammerhead ribozyme