title: Sustained inhibition of HIV-1 replication by conditional expression of the E. coli-derived endoribonuclease MazF in CD4+ T cells.
abstract: Gene therapy using a Tat-dependent expression system of MazF, an ACA nucleotide sequence-specific endoribonuclease derived from Escherichia coli, in a retroviral vector appears to be an alternative approach to the treatment of human immunodeficiency virus type 1 (HIV-1) infection. MazF can cleave HIV-1 RNA, since it has more than 240 ACA sequences. Significant inhibition of viral replication, irrespective of HIV-1 strains, was observed in CD4(+) T cells that had been transduced with the MazF-expressing retroviral vector (MazF-T cells). The growth and viability of MazF-T cells were not affected by HIV-1 infection. Interestingly, the infectivity of HIV-1 produced from MazF-T cells was found to be lower than that from control CD4(+) T cells. A long-term culture experiment with HIV-1-infected cells revealed that viral replication was always lower in MazF-T cells than in CD4(+) T cells transduced with or without a control vector for more than 200 days. MazF was expressed and mainly localized in the cytoplasm of the infected cells. Unlike in CD4(+) T cells, the expression level of Tat gradually decreased rather than increased in MazF-T cells after HIV-1 infection. As a consequence, the expression level of MazF appeared to be well regulated and sustained during HIV-1 infection in MazF-T cells. Furthermore, the levels of cellular mRNA were not affected by HIV-1 infection. Thus, the Tat-dependent MazF expression system has great potential for inhibition of HIV-1 replication in vivo without apparent toxicity and may be able to avoid the emergence of resistant strains.
authors: Division of Antiviral Chemotherapy, Center for Chronic Viral Diseases, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544, Japan.
authors: Mika
authors: M
authors: Okamoto
authors: Hideto
authors: H
authors: Chono
authors: Yasuhiro
authors: Y
authors: Kawano
authors: Naoki
authors: N
authors: Saito
authors: Hiroshi
authors: H
authors: Tsuda
authors: Koichi
authors: K
authors: Inoue
authors: Ikunoshin
authors: I
authors: Kato
authors: Junichi
authors: J
authors: Mineno
authors: Masanori
authors: M
authors: Baba
mesh_terms: D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism* / Q000821:virology*; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D024921:Drug Resistance, Multiple, Viral / Q000235:genetics; D004722:Endoribonucleases / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D005786:Gene Expression Regulation; D023061:Gene Order; D005822:Genetic Vectors / Q000235:genetics; D015497:HIV-1 / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000378:metabolism / Q000821:virology; D009154:Mutation; D021381:Protein Transport; D012190:Retroviridae / Q000235:genetics; D014161:Transduction, Genetic; D056189:Viral Tropism; D014779:Virus Replication; D054322:tat Gene Products, Human Immunodeficiency Virus / Q000235:genetics / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C422955:MazF protein, E coli; D054322:tat Gene Products, Human Immunodeficiency Virus; D004722:Endoribonucleases