Transcriptional competence of the integrated HIV-1 provirus at the nuclear periphery

Authors

  • Mariacarolina Dieudonné,

    1. Laboratory of Molecular Virology, International Centre for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy
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  • Paolo Maiuri,

    1. Laboratory of Molecular Virology, International Centre for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy
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  • Chiara Biancotto,

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    • Present address: IFOM-IEO, Milan, Italy
  • Anna Knezevich,

    1. Laboratory of Molecular Virology, International Centre for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy
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  • Anna Kula,

    1. Laboratory of Molecular Virology, International Centre for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy
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  • Marina Lusic,

    1. Laboratory of Molecular Medicine, International Centre for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy
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  • Alessandro Marcello

    Corresponding author
    1. Laboratory of Molecular Virology, International Centre for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy
    • Corresponding author. Laboratory of Molecular Virology, International Centre for Genetic Engineering and Biotechnology (ICGEB), Padriciano 99, Trieste 34149, Italy. Tel.: +39 040 375 7384; Fax: +39 040 226 555; E-mail: marcello@icgeb.org

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Abstract

Spatial distribution of genes within the nucleus contributes to transcriptional control, allowing optimal gene expression as well as constitutive or regulated gene repression. Human immunodeficiency virus type 1 (HIV-1) integrates into host chromatin to transcribe and replicate its genome. Lymphocytes harbouring a quiescent but inducible provirus are a challenge to viral eradication in infected patients undergoing antiviral therapy. Therefore, our understanding of the contribution of sub-nuclear positioning to viral transcription may also have far-reaching implications in the pathology of the infection. To gain an insight into the conformation of chromatin at the site of HIV-1 integration, we investigated lymphocytes carrying a single latent provirus. In the silenced state, the provirus was consistently found at the nuclear periphery, associated in trans with a pericentromeric region of chromosome 12 in a significant number of quiescent cells. After induction of the transcription, this association was lost, although the location of the transcribing provirus remained peripheral. These results, extended to several other cell clones, unveil a novel mechanism of transcriptional silencing involved in HIV-1 post-transcriptional latency and reinforce the notion that gene transcription may also occur at the nuclear periphery.

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