Reza Nazari
PhD in Molecular Genetics
Rose Pharmed Biotechnology Co. · R&D

Topics (4)

Publications (6) View all

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    Article: HIV-1 gene therapy at pre-integration and provirus DNA levels.
    Reza Nazari, Sadhna Joshi
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    ABSTRACT: AIDS is the result of infection by a lentivirus, HIV-1, which primarily infects CD4+ T cells and macrophages. There is presently no vaccine and none will be available in the foreseeable future. Highly active antiretroviral drug therapy has led to a dramatic reduction of viral load in many infected individuals, and has decreased mortality in the developing world. However, besides long-term drug toxicity and eventual emergence of drug-resistant strains, withdrawal from the therapy (even after effective and continuous treatment) results in re-emergence of the virus since cells harbouring the latent viral reservoirs persist. These issues highlight the need for alternative therapies, e.g. gene therapy. This review summarizes various gene therapy strategies that target early stages of HIV-1 life cycle. We will cover strategies that allow interference at the level of the released virion RNA, reverse transcriptase, pre-integration complex, integrase, dsDNA and provirus DNA in gene-modified cells.
    Current Gene Therapy 03/2009; 9(1):20-5. · 3.39 Impact Factor
  • Article: Exploring the potential of group II introns to inactivate human immunodeficiency virus type 1.
    Reza Nazari, Sadhna Joshi
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    ABSTRACT: This study examined whether insertion of a mobile group II intron into infectious human immunodeficiency virus type 1 (HIV-1) provirus DNA could inhibit virus replication. Introns targeted against two sites within the integrase-coding region were used. The intron-inserted HIV-1 provirus DNA clones were isolated and tested for virus replication. Similar amounts of HIV-1 RNA, Gag protein and progeny virus were produced from HIV-1 provirus DNA and intron-inserted HIV-1 provirus DNA. However, when the progeny virus was tested for its infectivity, although the group II intron-inserted HIV-1 RNA was packaged and reverse-transcribed, the dsDNA failed to integrate, as expected in the absence of a functional integrase, and virus replication was aborted. These results demonstrate that group II introns can confer 'complete' inhibition of HIV-1 replication at the intended step and should be further exploited for HIV-1 gene therapy and other targeted genetic repairs.
    Journal of General Virology 11/2008; 89(Pt 10):2605-10. · 3.36 Impact Factor
  • Article: Inhibition of human immunodeficiency virus-1 entry using vectors expressing a multimeric hammerhead ribozyme targeting the CCR5 mRNA.
    Reza Nazari, Xue Zhong Ma, Sadhna Joshi
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    ABSTRACT: Rz1-7 is a multimeric hammerhead ribozyme targeting seven unique sites within the human CCR5 mRNA that is active in vitro. Mouse stem cell virus-based MGIN and human immunodeficiency virus (HIV)-1-based HEG1 vectors were used to express Rz1-7 in a human CD4+ T lymphoid cell line. Stable transductants expressed Rz1-7, which was further shown to be active, since CCR5 mRNA and surface CCR5 protein expression levels decreased. High levels of progeny virus were produced when the transduced cells were challenged with an X4-tropic HIV-1 (NL4-3) strain, suggesting that Rz1-7 expression does not affect X4-tropic virus replication. When the transduced cells expressing Rz1-7 were challenged with the R5-tropic HIV-1 (BaL) strain, 99-100% inhibition of progeny virus production was observed for the duration of the experiment (approximately 2 months). When the cells were precultured for 2-3 months prior to HIV-1 infection, inhibition was more prominent in cells transduced with MGIN-Rz1-7 than with HEG1-Rz1-7. Inhibition occurred at the level of viral entry, as no HIV-1 DNA could be detected. These results demonstrate that Rz1-7 confers excellent inhibition of R5-tropic HIV-1 replication at the level of entry. Therefore, we anticipate that this multimeric ribozyme will be beneficial for HIV-1 gene therapy.
    Journal of General Virology 10/2008; 89(Pt 9):2252-61. · 3.36 Impact Factor
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    Article: CCR5 as target for HIV-1 gene therapy.
    Reza Nazari, Sadhna Joshi
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    ABSTRACT: Acquired immune deficiency syndrome (AIDS) is caused by a lentivirus, human immunodeficiency virus type-1 (HIV-1). Viral entry is mediated by specific interaction of the viral envelope (Env) glycoprotein with a cell surface molecule CD4 which serves as the primary receptor and a chemokine (C-C or C-X-C motif) receptor CCR5 or CXCR4 which serves as a co-receptor. The viral Env, the cellular CD4 receptor, or the CCR5/CXCR4 co-receptors may be the targets of therapeutic interventions. Compared to the high variability of the viral Env protein, lack of variability in the CD4 receptor and the CCR5 or CXCR4 co-receptor makes them better targets to prevent viral entry. Downregulation of CD4 or CXCR4 is likely to have harmful consequences for the immune function or cellular maturation and homing. In contrast, individuals who lack functional CCR5 have no apparent immune defects, and show decreased susceptibility to HIV-1 infection and delayed progression to AIDS. CCR5 is essential for HIV-1 infection through all routes of transmission. Therefore, its downregulation may not only prevent disease progression, but also the spread of HIV-1 transmission. To block CCR5 function, a number of molecules were developed, including low molecular weight compounds, chemokines, N-terminally-modified chemokine analogues, chemokine-derived molecules, chemokine-based synthetic peptides, and anti-CCR5 monoclonal antibodies. Gene therapy strategies were developed using intrakines and intrabodies to prevent cell surface expression of CCR5 and zinc finger-nucleases, or using small interfering RNAs, antisense RNAs, or ribozymes to decrease co-receptor synthesis. This review describes the importance of targeting CCR5 and summarizes the status of various anti-CCR5 gene therapy strategies.
    Current Gene Therapy 09/2008; 8(4):264-72. · 3.39 Impact Factor
  • Article: Development and testing of retroviral vectors expressing multimeric hammerhead ribozymes targeted against all major clades of HIV-1.
    Ali Ramezani, Xue Zhong Ma, Reza Nazari, Sadhna Joshi
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    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.
    Frontiers in Bioscience 03/2002; 7:a29-36. · 3.52 Impact Factor
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