title: Inhibition of HIV-1 in CEM cells by a potent TAR decoy.
abstract: TAR decoys are short RNA oligonucleotides, corresponding to the HIV TAR sequence, which inhibit HIV expression and replication by blocking the binding of the HIV regulatory protein Tat to the authentic TAR region. In previous studies, TAR decoys expressed from a tRNA polIII promoter were moderately effective at inhibiting HIV in isolated human T cell lines and less effective at inhibiting HIV in peripheral blood CD4+ T cells. In this study, a series of modifications was introduced into the tRNA expression cassette in order to improve their effectiveness. These modifications included the addition of sequences which are predicted to have stem-loop secondary structures and addition of a wild-type tRNA processing site. TAR decoy RNA expressed in CEM cells from modified tRNA-based expression cassettes yielded five- to 20-fold more TAR transcripts than unmodified tRNA-based expression cassettes. HIV replication, as measured by a flow cytometric method to quantify intracellular viral p24 expression, was significantly reduced in polyclonal populations of CEM cells expressing a modified tRNA-TAR transcript that contains a wild-type tRNA processing site and stem-loops 5' and 3' to the TAR sequence. Similar modifications to the tRNA expression cassette also increased the intracellular concentration of a random test oligonucleotide, indicating that this improved expression system may also be useful for antisense and ribozyme based gene inhibition strategies.
authors.affiliation: Program of Molecular Biology, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.
authors.forename: S W
authors.initials: SW
authors.lastname: Lee
authors.forename: H F
authors.initials: HF
authors.lastname: Gallardo
authors.forename: O
authors.initials: O
authors.lastname: Gaspar
authors.forename: C
authors.initials: C
authors.lastname: Smith
authors.forename: E
authors.initials: E
authors.lastname: Gilboa
mesh_terms: D000998:Antiviral Agents / Q000494:pharmacology*; D001483:Base Sequence; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000821:virology; D002460:Cell Line; D002478:Cells, Cultured; D015870:Gene Expression; D015696:Gene Products, tat / Q000378:metabolism*; D005822:Genetic Vectors; D016655:HIV Core Protein p24 / Q000032:analysis / Q000096:biosynthesis; D015497:HIV-1 / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D006801:Humans; D008969:Molecular Sequence Data; D008979:Moloney murine leukemia virus / Q000235:genetics; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides; D009843:Oligoribonucleotides / Q000378:metabolism / Q000494:pharmacology*; D011401:Promoter Regions, Genetic; D016337:RNA, Catalytic / Q000378:metabolism; D012343:RNA, Transfer / Q000096:biosynthesis* / Q000737:chemistry; D012045:Regulatory Sequences, Nucleic Acid; D013601:T-Lymphocytes / Q000276:immunology / Q000821:virology*; D014158:Transcription, Genetic; D014162:Transfection; D014407:Tumor Cells, Cultured; D014779:Virus Replication / Q000187:drug effects*; D054322:tat Gene Products, Human Immunodeficiency Virus
chemical_list: D000998:Antiviral Agents; D015696:Gene Products, tat; D016655:HIV Core Protein p24; D009838:Oligodeoxyribonucleotides; D009843:Oligoribonucleotides; D016337:RNA, Catalytic; D054322:tat Gene Products, Human Immunodeficiency Virus; D012343:RNA, Transfer