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Pathak R, Esnault C, Radhakrishnan R, Singh PK, Zhang H, Dale R, Anand A, Bedwell GJ, Engelman AN, Rabi A, Hormoz S, Singh P, Levin HL. The role of LEDGF in transcription is exploited by HIV-1 to position integration. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.29.601340. [PMID: 39005447 PMCID: PMC11244883 DOI: 10.1101/2024.06.29.601340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
HIV-1 integration occurs across actively transcribed genes due to the interaction of integrase with host chromatin factor LEDGF. Although LEDGF was originally isolated as a co-activator that stimulates promoter activity in purified systems, this role is inconsistent with LEDGF-mediated integration across gene bodies and with data indicating LEDGF is a histone chaperone that promotes transcriptional elongation. We found LEDGF is enriched in pronounced peaks that match the enrichments of H3K4me3 and RNA Pol II at transcription start sites (TSSs) of active promoters. Our genome-wide chromatin mapping revealed that MLL1 had a dominant role in recruiting LEDGF to promoters and the presence of LEDGF recruits RNA Pol II. Enrichment of LEDGF at TSSs correlates strongly with levels of integration across the transcribed sequences, indicating that LEDGF at TSSs contributed to integration across gene bodies. Although the N-terminal Pro-Trp-Trp-Pro (PWWP) domain of LEDGF interacts with nucleosomes containing H3K36me3, a modification thought to recruit LEDGF to chromatin, we found H3K36me3 does not contribute to gene specificity of integration. These data support a dual role model of LEDGF where it is tethered to promoters by MLL1 and recruits RNA Pol II. Subsequently, LEDGF travels across genes to effect HIV-1 integration. Our data also provides a mechanistic context for the contribution made by LEDGF to MLL1-based infant acute leukemia and acute myeloid leukemia in adults.
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Abdalla AL, Guajardo-Contreras G, Mouland AJ. A Canadian Survey of Research on HIV-1 Latency-Where Are We Now and Where Are We Heading? Viruses 2024; 16:229. [PMID: 38400005 PMCID: PMC10891605 DOI: 10.3390/v16020229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 01/26/2024] [Accepted: 01/30/2024] [Indexed: 02/25/2024] Open
Abstract
Worldwide, almost 40 million people are currently living with HIV-1. The implementation of cART inhibits HIV-1 replication and reduces viremia but fails to eliminate HIV-1 from latently infected cells. These cells are considered viral reservoirs from which HIV-1 rebounds if cART is interrupted. Several efforts have been made to identify these cells and their niches. There has been little success in diminishing the pool of latently infected cells, underscoring the urgency to continue efforts to fully understand how HIV-1 establishes and maintains a latent state. Reactivating HIV-1 expression in these cells using latency-reversing agents (LRAs) has been successful, but only in vitro. This review aims to provide a broad view of HIV-1 latency, highlighting Canadian contributions toward these aims. We will summarize the research efforts conducted in Canadian labs to understand the establishment of latently infected cells and how this informs curative strategies, by reviewing how HIV latency is established, which cells are latently infected, what methodologies have been developed to characterize them, how new compounds are discovered and evaluated as potential LRAs, and what clinical trials aim to reverse latency in people living with HIV (PLWH).
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Affiliation(s)
- Ana Luiza Abdalla
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montreal, QC H3T 1E2, Canada; (A.L.A.); (G.G.-C.)
- Department of Microbiology and Immunology, McGill University, Montreal, QC H3A 2B4, Canada
| | - Gabriel Guajardo-Contreras
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montreal, QC H3T 1E2, Canada; (A.L.A.); (G.G.-C.)
- Department of Medicine, McGill University, Montreal, QC H4A 3J1, Canada
| | - Andrew J. Mouland
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montreal, QC H3T 1E2, Canada; (A.L.A.); (G.G.-C.)
- Department of Microbiology and Immunology, McGill University, Montreal, QC H3A 2B4, Canada
- Department of Medicine, McGill University, Montreal, QC H4A 3J1, Canada
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3
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Jang S, Engelman AN. Capsid-host interactions for HIV-1 ingress. Microbiol Mol Biol Rev 2023; 87:e0004822. [PMID: 37750702 PMCID: PMC10732038 DOI: 10.1128/mmbr.00048-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/27/2023] Open
Abstract
The HIV-1 capsid, composed of approximately 1,200 copies of the capsid protein, encases genomic RNA alongside viral nucleocapsid, reverse transcriptase, and integrase proteins. After cell entry, the capsid interacts with a myriad of host factors to traverse the cell cytoplasm, pass through the nuclear pore complex (NPC), and then traffic to chromosomal sites for viral DNA integration. Integration may very well require the dissolution of the capsid, but where and when this uncoating event occurs remains hotly debated. Based on size constraints, a long-prevailing view was that uncoating preceded nuclear transport, but recent research has indicated that the capsid may remain largely intact during nuclear import, with perhaps some structural remodeling required for NPC traversal. Completion of reverse transcription in the nucleus may further aid capsid uncoating. One canonical type of host factor, typified by CPSF6, leverages a Phe-Gly (FG) motif to bind capsid. Recent research has shown these peptides reside amid prion-like domains (PrLDs), which are stretches of protein sequence devoid of charged residues. Intermolecular PrLD interactions along the exterior of the capsid shell impart avid host factor binding for productive HIV-1 infection. Herein we overview capsid-host interactions implicated in HIV-1 ingress and discuss important research questions moving forward. Highlighting clinical relevance, the long-acting ultrapotent inhibitor lenacapavir, which engages the same capsid binding pocket as FG host factors, was recently approved to treat people living with HIV.
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Affiliation(s)
- Sooin Jang
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Alan N. Engelman
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
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4
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Renzi G, Carta F, Supuran CT. The Integrase: An Overview of a Key Player Enzyme in the Antiviral Scenario. Int J Mol Sci 2023; 24:12187. [PMID: 37569561 PMCID: PMC10419282 DOI: 10.3390/ijms241512187] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 07/23/2023] [Accepted: 07/26/2023] [Indexed: 08/13/2023] Open
Abstract
Integration of a desossiribonucleic acid (DNA) copy of the viral ribonucleic acid (RNA) into host genomes is a fundamental step in the replication cycle of all retroviruses. The highly conserved virus-encoded Integrase enzyme (IN; EC 2.7.7.49) catalyzes such a process by means of two consecutive reactions named 3'-processing (3-P) and strand transfer (ST). The Authors report and discuss the major discoveries and advances which mainly contributed to the development of Human Immunodeficiency Virus (HIV) -IN targeted inhibitors for therapeutic applications. All the knowledge accumulated over the years continues to serve as a valuable resource for the design and development of effective antiretroviral drugs.
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Affiliation(s)
| | - Fabrizio Carta
- Neuroscienze, Psicologia, Area del Farmaco e Salute del Bambino (NEUROFARBA) Department, Sezione di Scienze Farmaceutiche e Nutraceutiche, University of Florence, Via Ugo Schiff 6, Sesto Fiorentino, 50019 Florence, Italy; (G.R.); (C.T.S.)
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5
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Pellaers E, Bhat A, Christ F, Debyser Z. Determinants of Retroviral Integration and Implications for Gene Therapeutic MLV-Based Vectors and for a Cure for HIV-1 Infection. Viruses 2022; 15:32. [PMID: 36680071 PMCID: PMC9861059 DOI: 10.3390/v15010032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/14/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022] Open
Abstract
To complete their replication cycle, retroviruses need to integrate a DNA copy of their RNA genome into a host chromosome. Integration site selection is not random and is driven by multiple viral and cellular host factors specific to different classes of retroviruses. Today, overwhelming evidence from cell culture, animal experiments and clinical data suggests that integration sites are important for retroviral replication, oncogenesis and/or latency. In this review, we will summarize the increasing knowledge of the mechanisms underlying the integration site selection of the gammaretrovirus MLV and the lentivirus HIV-1. We will discuss how host factors of the integration site selection of retroviruses may steer the development of safer viral vectors for gene therapy. Next, we will discuss how altering the integration site preference of HIV-1 using small molecules could lead to a cure for HIV-1 infection.
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Affiliation(s)
| | | | | | - Zeger Debyser
- Molecular Virology and Gene Therapy, KU Leuven, Herestraat 49, 3000 Leuven, Belgium
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6
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Complex Relationships between HIV-1 Integrase and Its Cellular Partners. Int J Mol Sci 2022; 23:ijms232012341. [PMID: 36293197 PMCID: PMC9603942 DOI: 10.3390/ijms232012341] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 10/09/2022] [Accepted: 10/11/2022] [Indexed: 11/06/2022] Open
Abstract
RNA viruses, in pursuit of genome miniaturization, tend to employ cellular proteins to facilitate their replication. HIV-1, one of the most well-studied retroviruses, is not an exception. There is numerous evidence that the exploitation of cellular machinery relies on nucleic acid-protein and protein-protein interactions. Apart from Vpr, Vif, and Nef proteins that are known to regulate cellular functioning via interaction with cell components, another viral protein, integrase, appears to be crucial for proper virus-cell dialog at different stages of the viral life cycle. The goal of this review is to summarize and systematize existing data on known cellular partners of HIV-1 integrase and their role in the HIV-1 life cycle.
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Allosteric Integrase Inhibitor Influences on HIV-1 Integration and Roles of LEDGF/p75 and HDGFL2 Host Factors. Viruses 2022; 14:v14091883. [PMID: 36146690 PMCID: PMC9502684 DOI: 10.3390/v14091883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 08/11/2022] [Accepted: 08/24/2022] [Indexed: 02/01/2023] Open
Abstract
Allosteric integrase (IN) inhibitors (ALLINIs), which are promising preclinical compounds that engage the lens epithelium-derived growth factor (LEDGF)/p75 binding site on IN, can inhibit different aspects of human immunodeficiency virus 1 (HIV-1) replication. During the late phase of replication, ALLINIs induce aberrant IN hyper-multimerization, the consequences of which disrupt IN binding to genomic RNA and virus particle morphogenesis. During the early phase of infection, ALLINIs can suppress HIV-1 integration into host genes, which is also observed in LEDGF/p75-depelted cells. Despite this similarity, the roles of LEDGF/p75 and its paralog hepatoma-derived growth factor like 2 (HDGFL2) in ALLINI-mediated integration retargeting are untested. Herein, we mapped integration sites in cells knocked out for LEDGF/p75, HDGFL2, or both factors, which revealed that these two proteins in large part account for ALLINI-mediated integration retargeting during the early phase of infection. We also determined that ALLINI-treated viruses are defective during the subsequent round of infection for integration into genes associated with speckle-associated domains, which are naturally highly targeted for HIV-1 integration. Class II IN mutant viruses with alterations distal from the LEDGF/p75 binding site moreover shared this integration retargeting phenotype. Altogether, our findings help to inform the molecular bases and consequences of ALLINI action.
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8
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Ballandras-Colas A, Chivukula V, Gruszka DT, Shan Z, Singh PK, Pye VE, McLean RK, Bedwell GJ, Li W, Nans A, Cook NJ, Fadel HJ, Poeschla EM, Griffiths DJ, Vargas J, Taylor IA, Lyumkis D, Yardimci H, Engelman AN, Cherepanov P. Multivalent interactions essential for lentiviral integrase function. Nat Commun 2022; 13:2416. [PMID: 35504909 PMCID: PMC9065133 DOI: 10.1038/s41467-022-29928-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 04/07/2022] [Indexed: 12/24/2022] Open
Abstract
A multimer of retroviral integrase (IN) synapses viral DNA ends within a stable intasome nucleoprotein complex for integration into a host cell genome. Reconstitution of the intasome from the maedi-visna virus (MVV), an ovine lentivirus, revealed a large assembly containing sixteen IN subunits1. Herein, we report cryo-EM structures of the lentiviral intasome prior to engagement of target DNA and following strand transfer, refined at 3.4 and 3.5 Å resolution, respectively. The structures elucidate details of the protein-protein and protein-DNA interfaces involved in lentiviral intasome formation. We show that the homomeric interfaces involved in IN hexadecamer formation and the α-helical configuration of the linker connecting the C-terminal and catalytic core domains are critical for MVV IN strand transfer activity in vitro and for virus infectivity. Single-molecule microscopy in conjunction with photobleaching reveals that the MVV intasome can bind a variable number, up to sixteen molecules, of the lentivirus-specific host factor LEDGF/p75. Concordantly, ablation of endogenous LEDGF/p75 results in gross redistribution of MVV integration sites in human and ovine cells. Our data confirm the importance of the expanded architecture observed in cryo-EM studies of lentiviral intasomes and suggest that this organization underlies multivalent interactions with chromatin for integration targeting to active genes.
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Affiliation(s)
- Allison Ballandras-Colas
- Chromatin Structure and Mobile DNA Laboratory, The Francis Crick Institute, London, UK
- Institut de Biologie Structurale (IBS) CNRS, CEA, University Grenoble, Grenoble, France
| | - Vidya Chivukula
- Chromatin Structure and Mobile DNA Laboratory, The Francis Crick Institute, London, UK
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY, 10016, USA
| | - Dominika T Gruszka
- Single Molecule Imaging of Genome Duplication and Maintenance Laboratory, The Francis Crick Institute, London, UK
- Biological Physics Research Group, Clarendon Laboratory, Department of Physics and Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford, UK
| | - Zelin Shan
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Parmit K Singh
- Department of Cancer Immunology & Virology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Valerie E Pye
- Chromatin Structure and Mobile DNA Laboratory, The Francis Crick Institute, London, UK
| | - Rebecca K McLean
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, UK
- The Pirbright Institute, Ash Road, Pirbright, Woking, GU24 0NF, UK
| | - Gregory J Bedwell
- Department of Cancer Immunology & Virology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Wen Li
- Department of Cancer Immunology & Virology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Andrea Nans
- Structural Biology Science Technology Platform, The Francis Crick Institute, London, UK
| | - Nicola J Cook
- Chromatin Structure and Mobile DNA Laboratory, The Francis Crick Institute, London, UK
| | - Hind J Fadel
- Division of Infectious Diseases, Mayo Clinic, Rochester, MN, USA
| | - Eric M Poeschla
- Division of Infectious Diseases, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - David J Griffiths
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, UK
| | - Javier Vargas
- Departmento de Óptica, Universidad Complutense de Madrid, Madrid, Spain
| | - Ian A Taylor
- Macromolecular Structure Laboratory, The Francis Crick Institute, London, UK
| | - Dmitry Lyumkis
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA, USA.
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA.
| | - Hasan Yardimci
- Single Molecule Imaging of Genome Duplication and Maintenance Laboratory, The Francis Crick Institute, London, UK.
| | - Alan N Engelman
- Department of Cancer Immunology & Virology, Dana-Farber Cancer Institute, Boston, MA, USA.
- Department of Medicine, Harvard Medical School, Boston, MA, USA.
| | - Peter Cherepanov
- Chromatin Structure and Mobile DNA Laboratory, The Francis Crick Institute, London, UK.
- Department of Infectious Disease, St-Mary's Campus, Imperial College London, London, UK.
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9
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Abstract
A hallmark of retroviral replication is establishment of the proviral state, wherein a DNA copy of the viral RNA genome is stably incorporated into a host cell chromosome. Integrase is the viral enzyme responsible for the catalytic steps involved in this process, and integrase strand transfer inhibitors are widely used to treat people living with HIV. Over the past decade, a series of X-ray crystallography and cryogenic electron microscopy studies have revealed the structural basis of retroviral DNA integration. A variable number of integrase molecules congregate on viral DNA ends to assemble a conserved intasome core machine that facilitates integration. The structures additionally informed on the modes of integrase inhibitor action and the means by which HIV acquires drug resistance. Recent years have witnessed the development of allosteric integrase inhibitors, a highly promising class of small molecules that antagonize viral morphogenesis. In this Review, we explore recent insights into the organization and mechanism of the retroviral integration machinery and highlight open questions as well as new directions in the field.
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Yoder KE, Rabe AJ, Fishel R, Larue RC. Strategies for Targeting Retroviral Integration for Safer Gene Therapy: Advances and Challenges. Front Mol Biosci 2021; 8:662331. [PMID: 34055882 PMCID: PMC8149907 DOI: 10.3389/fmolb.2021.662331] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 04/29/2021] [Indexed: 12/11/2022] Open
Abstract
Retroviruses are obligate intracellular parasites that must integrate a copy of the viral genome into the host DNA. The integration reaction is performed by the viral enzyme integrase in complex with the two ends of the viral cDNA genome and yields an integrated provirus. Retroviral vector particles are attractive gene therapy delivery tools due to their stable integration. However, some retroviral integration events may dysregulate host oncogenes leading to cancer in gene therapy patients. Multiple strategies to target retroviral integration, particularly to genetic safe harbors, have been tested with limited success. Attempts to target integration may be limited by the multimerization of integrase or the presence of host co-factors for integration. Several retroviral integration complexes have evolved a mechanism of tethering to chromatin via a host protein. Integration host co-factors bind chromatin, anchoring the complex and allowing integration. The tethering factor allows for both close proximity to the target DNA and specificity of targeting. Each retrovirus appears to have distinct preferences for DNA sequence and chromatin features at the integration site. Tethering factors determine the preference for chromatin features, but do not affect the subtle sequence preference at the integration site. The sequence preference is likely intrinsic to the integrase protein. New developments may uncouple the requirement for a tethering factor and increase the ability to redirect retroviral integration.
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Affiliation(s)
- Kristine E Yoder
- Department of Cancer Biology and Genetics, College of Medicine, The Ohio State University, Columbus, OH, United States
| | - Anthony J Rabe
- Department of Cancer Biology and Genetics, College of Medicine, The Ohio State University, Columbus, OH, United States
| | - Richard Fishel
- Department of Cancer Biology and Genetics, College of Medicine, The Ohio State University, Columbus, OH, United States
| | - Ross C Larue
- Department of Cancer Biology and Genetics, College of Medicine, The Ohio State University, Columbus, OH, United States
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11
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Bedwell GJ, Engelman AN. Factors that mold the nuclear landscape of HIV-1 integration. Nucleic Acids Res 2021; 49:621-635. [PMID: 33337475 PMCID: PMC7826272 DOI: 10.1093/nar/gkaa1207] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 11/26/2020] [Indexed: 12/17/2022] Open
Abstract
The integration of retroviral reverse transcripts into the chromatin of the cells that they infect is required for virus replication. Retroviral integration has far-reaching consequences, from perpetuating deadly human diseases to molding metazoan evolution. The lentivirus human immunodeficiency virus 1 (HIV-1), which is the causative agent of the AIDS pandemic, efficiently infects interphase cells due to the active nuclear import of its preintegration complex (PIC). To enable integration, the PIC must navigate the densely-packed nuclear environment where the genome is organized into different chromatin states of varying accessibility in accordance with cellular needs. The HIV-1 capsid protein interacts with specific host factors to facilitate PIC nuclear import, while additional interactions of viral integrase, the enzyme responsible for viral DNA integration, with cellular nuclear proteins and nucleobases guide integration to specific chromosomal sites. HIV-1 integration favors transcriptionally active chromatin such as speckle-associated domains and disfavors heterochromatin including lamina-associated domains. In this review, we describe virus-host interactions that facilitate HIV-1 PIC nuclear import and integration site targeting, highlighting commonalities among factors that participate in both of these steps. We moreover discuss how the nuclear landscape influences HIV-1 integration site selection as well as the establishment of active versus latent virus infection.
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Affiliation(s)
- Gregory J Bedwell
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
- Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Alan N Engelman
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
- Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
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12
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Li W, Singh PK, Sowd GA, Bedwell GJ, Jang S, Achuthan V, Oleru AV, Wong D, Fadel HJ, Lee K, KewalRamani VN, Poeschla EM, Herschhorn A, Engelman AN. CPSF6-Dependent Targeting of Speckle-Associated Domains Distinguishes Primate from Nonprimate Lentiviral Integration. mBio 2020; 11:e02254-20. [PMID: 32994325 PMCID: PMC7527728 DOI: 10.1128/mbio.02254-20] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 08/28/2020] [Indexed: 12/19/2022] Open
Abstract
Lentiviral DNA integration favors transcriptionally active chromatin. We previously showed that the interaction of human immunodeficiency virus type 1 (HIV-1) capsid with cleavage and polyadenylation specificity factor 6 (CPSF6) localizes viral preintegration complexes (PICs) to nuclear speckles for integration into transcriptionally active speckle-associated domains (SPADs). In the absence of the capsid-CPSF6 interaction, PICs uncharacteristically accumulate at the nuclear periphery and target heterochromatic lamina-associated domains (LADs) for integration. The integrase-binding protein lens epithelium-derived growth factor (LEDGF)/p75 in contrast to CPSF6 predominantly functions to direct HIV-1 integration to interior regions of transcription units. Though CPSF6 and LEDGF/p75 can reportedly interact with the capsid and integrase proteins of both primate and nonprimate lentiviruses, the extents to which these different viruses target SPADs versus LADs, as well as their dependencies on CPSF6 and LEDGF/p75 for integration targeting, are largely unknown. Here, we mapped 5,489,157 primate and nonprimate lentiviral integration sites in HEK293T and Jurkat T cells as well as derivative cells that were knocked out or knocked down for host factor expression. Despite marked preferences of all lentiviruses to target genes for integration, nonprimate lentiviruses only marginally favored SPADs, with corresponding upticks in LAD-proximal integration. While LEDGF/p75 knockout disrupted the intragenic integration profiles of all lentiviruses similarly, CPSF6 depletion specifically counteracted SPAD integration targeting by primate lentiviruses. CPSF6 correspondingly failed to appreciably interact with nonprimate lentiviral capsids. We conclude that primate lentiviral capsid proteins evolved to interact with CPSF6 to optimize PIC localization for integration into transcriptionally active SPADs.IMPORTANCE Integration is the defining step of the retroviral life cycle and underlies the inability to cure HIV/AIDS through the use of intensified antiviral therapy. The reservoir of latent, replication-competent proviruses that forms early during HIV infection reseeds viremia when patients discontinue medication. HIV cure research is accordingly focused on the factors that guide provirus formation and associated chromatin environments that regulate transcriptional reactivation, and studies of orthologous infectious agents such as nonprimate lentiviruses can inform basic principles of HIV biology. HIV-1 utilizes the integrase-binding protein LEDGF/p75 and the capsid interactor CPSF6 to target speckle-associated domains (SPADs) for integration. However, the extent to which these two host proteins regulate integration of other lentiviruses is largely unknown. Here, we mapped millions of retroviral integration sites in cell lines that were depleted for LEDGF/p75 and/or CPSF6. Our results reveal that primate lentiviruses uniquely target SPADs for integration in a CPSF6-dependent manner.
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Affiliation(s)
- Wen Li
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Parmit K Singh
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Gregory A Sowd
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Gregory J Bedwell
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Sooin Jang
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Vasudevan Achuthan
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Amarachi V Oleru
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
| | - Doris Wong
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
| | - Hind J Fadel
- Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - KyeongEun Lee
- Basic Research Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, USA
| | - Vineet N KewalRamani
- Basic Research Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, USA
| | - Eric M Poeschla
- Division of Infectious Diseases, University of Colorado Denver School of Medicine, Aurora, Colorado, USA
| | - Alon Herschhorn
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Alan N Engelman
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
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13
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Kleinpeter AB, Freed EO. HIV-1 Maturation: Lessons Learned from Inhibitors. Viruses 2020; 12:E940. [PMID: 32858867 PMCID: PMC7552077 DOI: 10.3390/v12090940] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 08/19/2020] [Accepted: 08/20/2020] [Indexed: 02/06/2023] Open
Abstract
Since the emergence of HIV and AIDS in the early 1980s, the development of safe and effective therapies has accompanied a massive increase in our understanding of the fundamental processes that drive HIV biology. As basic HIV research has informed the development of novel therapies, HIV inhibitors have been used as probes for investigating basic mechanisms of HIV-1 replication, transmission, and pathogenesis. This positive feedback cycle has led to the development of highly effective combination antiretroviral therapy (cART), which has helped stall the progression to AIDS, prolong lives, and reduce transmission of the virus. However, to combat the growing rates of virologic failure and toxicity associated with long-term therapy, it is important to diversify our repertoire of HIV-1 treatments by identifying compounds that block additional steps not targeted by current drugs. Most of the available therapeutics disrupt early events in the replication cycle, with the exception of the protease (PR) inhibitors, which act at the virus maturation step. HIV-1 maturation consists of a series of biochemical changes that facilitate the conversion of an immature, noninfectious particle to a mature infectious virion. These changes include proteolytic processing of the Gag polyprotein by the viral protease (PR), structural rearrangement of the capsid (CA) protein, and assembly of individual CA monomers into hexamers and pentamers that ultimately form the capsid. Here, we review the development and therapeutic potential of maturation inhibitors (MIs), an experimental class of anti-HIV-1 compounds with mechanisms of action distinct from those of the PR inhibitors. We emphasize the key insights into HIV-1 biology and structure that the study of MIs has provided. We will focus on three distinct groups of inhibitors that block HIV-1 maturation: (1) compounds that block the processing of the CA-spacer peptide 1 (SP1) cleavage intermediate, the original class of compounds to which the term MI was applied; (2) CA-binding inhibitors that disrupt capsid condensation; and (3) allosteric integrase inhibitors (ALLINIs) that block the packaging of the viral RNA genome into the condensing capsid during maturation. Although these three classes of compounds have distinct structures and mechanisms of action, they share the ability to block the formation of the condensed conical capsid, thereby blocking particle infectivity.
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Affiliation(s)
| | - Eric O. Freed
- HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA;
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Engelman AN. Multifaceted HIV integrase functionalities and therapeutic strategies for their inhibition. J Biol Chem 2019; 294:15137-15157. [PMID: 31467082 DOI: 10.1074/jbc.rev119.006901] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Antiretroviral inhibitors that are used to manage HIV infection/AIDS predominantly target three enzymes required for virus replication: reverse transcriptase, protease, and integrase. Although integrase inhibitors were the last among this group to be approved for treating people living with HIV, they have since risen to the forefront of treatment options. Integrase strand transfer inhibitors (INSTIs) are now recommended components of frontline and drug-switch antiretroviral therapy formulations. Integrase catalyzes two successive magnesium-dependent polynucleotidyl transferase reactions, 3' processing and strand transfer, and INSTIs tightly bind the divalent metal ions and viral DNA end after 3' processing, displacing from the integrase active site the DNA 3'-hydroxyl group that is required for strand transfer activity. Although second-generation INSTIs present higher barriers to the development of viral drug resistance than first-generation compounds, the mechanisms underlying these superior barrier profiles are incompletely understood. A separate class of HIV-1 integrase inhibitors, the allosteric integrase inhibitors (ALLINIs), engage integrase distal from the enzyme active site, namely at the binding site for the cellular cofactor lens epithelium-derived growth factor (LEDGF)/p75 that helps to guide integration into host genes. ALLINIs inhibit HIV-1 replication by inducing integrase hypermultimerization, which precludes integrase binding to genomic RNA and perturbs the morphogenesis of new viral particles. Although not yet approved for human use, ALLINIs provide important probes that can be used to investigate the link between HIV-1 integrase and viral particle morphogenesis. Herein, I review the mechanisms of retroviral integration as well as the promises and challenges of using integrase inhibitors for HIV/AIDS management.
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Affiliation(s)
- Alan N Engelman
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts 02215 Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115
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15
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Noncovalent SUMO-interaction motifs in HIV integrase play important roles in SUMOylation, cofactor binding, and virus replication. Virol J 2019; 16:42. [PMID: 30940169 PMCID: PMC6446281 DOI: 10.1186/s12985-019-1134-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 02/21/2019] [Indexed: 12/12/2022] Open
Abstract
Background HIV integrase (IN) and its cellular cofactors, including lens-epithelium-derived growth factor (LEDGF/p75), Ku70, p300, and Rad52, are subject to small ubiquitin-like modifier (SUMO) modification. In addition to covalent SUMOylation, SUMO paralogs can also noncovalently bind proteins through SUMO-interacting motifs (SIMs). However, little is known about whether HIV IN contains SIMs and the roles of these motifs. Results We searched for the amino acid sequence of HIV IN and investigated three putative SIMs of IN: SIM1 72VILV75, SIM2 200IVDI203 and SIM3 257IKVV260. Our mutational analysis showed that 200IVDI203 and 257IKVV260 are two bona fide SIMs that mediate IN-SUMO noncovalent interactions. Additionally, a cell-based SUMOylation assay revealed that IN SIMs negatively regulate the SUMOylation of IN, as well as the interaction between IN and SUMO E2 conjugation enzyme Ubc9. Conversely, IN SIMs are required for its interactions with LEDGF/p75 but not with Ku70. Furthermore, our study reveals that SIM2 and SIM3 are required for the nuclear localization of IN. Finally, we investigated the impact of IN SIM2 and SIM3 on HIV single cycle replication in CD4+ C8166 T cells, and the results showed that viruses carrying IN SIM mutants are replication defective at the steps of the early viral life cycle, including reverse transcription, nuclear import and integration. Conclusion Our data suggested that the INSIM-SUMO interaction constitutes a new regulatory mechanism of IN functions and might be important for HIV-1 replication.
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Targeted editing of the PSIP1 gene encoding LEDGF/p75 protects cells against HIV infection. Sci Rep 2019; 9:2389. [PMID: 30787394 PMCID: PMC6382798 DOI: 10.1038/s41598-019-38718-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 11/08/2018] [Indexed: 12/14/2022] Open
Abstract
To fulfill a productive infection cycle the human immunodeficiency virus (HIV) relies on host-cell factors. Interference with these co-factors holds great promise in protecting cells against HIV infection. LEDGF/p75, encoded by the PSIP1 gene, is used by the integrase (IN) protein in the pre-integration complex of HIV to bind host-cell chromatin facilitating proviral integration. LEDGF/p75 depletion results in defective HIV replication. However, as part of its cellular function LEDGF/p75 tethers cellular proteins to the host-cell genome. We used site-specific editing of the PSIP1 locus using CRISPR/Cas to target the aspartic acid residue in position 366 and mutated it to asparagine (D366N) to disrupt the interaction with HIV IN but retain LEDGF/p75 cellular function. The resulting cell lines demonstrated successful disruption of the LEDGF/p75 HIV-IN interface without affecting interaction with cellular binding partners. In line with LEDGF/p75 depleted cells, D366N cells did not support HIV replication, in part due to decreased integration efficiency. In addition, we confirm the remaining integrated provirus is more silent. Taken together, these results support the potential of site-directed CRISPR/Cas9 mediated knock-in to render cells more resistant to HIV infection and provides an additional strategy to protect patient-derived T-cells against HIV-1 infection as part of cell-based therapy.
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Hultquist JF, Hiatt J, Schumann K, McGregor MJ, Roth TL, Haas P, Doudna JA, Marson A, Krogan NJ. CRISPR-Cas9 genome engineering of primary CD4 + T cells for the interrogation of HIV-host factor interactions. Nat Protoc 2019; 14:1-27. [PMID: 30559373 PMCID: PMC6637941 DOI: 10.1038/s41596-018-0069-7] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
CRISPR-Cas9 gene-editing strategies have revolutionized our ability to engineer the human genome for robust functional interrogation of complex biological processes. We have recently adapted this technology for use in primary human CD4+ T cells to create a high-throughput platform for analyzing the role of host factors in HIV infection and pathogenesis. Briefly, CRISPR-Cas9 ribonucleoproteins (crRNPs) are synthesized in vitro and delivered to activated CD4+ T cells by nucleofection. These cells are then assayed for editing efficiency and expanded for use in downstream cellular, genetic, or protein-based assays. This platform supports the rapid, arrayed generation of multiple gene manipulations and is widely adaptable across culture conditions, infection protocols, and downstream applications. Here, we present detailed protocols for crRNP synthesis, primary T-cell culture, 96-well nucleofection, molecular validation, and HIV infection, and discuss additional considerations for guide and screen design, as well as crRNP multiplexing. Taken together, this procedure allows high-throughput identification and mechanistic interrogation of HIV host factors in primary CD4+ T cells by gene knockout, validation, and HIV spreading infection in as little as 2-3 weeks.
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Affiliation(s)
- Judd F Hultquist
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, USA
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA, USA
- Institute for Virology and Immunology, J. David Gladstone Institutes, San Francisco, CA, USA
- Division of Infectious Diseases, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Joseph Hiatt
- Institute for Virology and Immunology, J. David Gladstone Institutes, San Francisco, CA, USA
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA
- Diabetes Center, University of California, San Francisco, San Francisco, CA, USA
- Medical Scientist Training Program, University of California, San Francisco, San Francisco, CA, USA
- Biomedical Sciences Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - Kathrin Schumann
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA
- Diabetes Center, University of California, San Francisco, San Francisco, CA, USA
| | - Michael J McGregor
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, USA
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA, USA
- Institute for Virology and Immunology, J. David Gladstone Institutes, San Francisco, CA, USA
| | - Theodore L Roth
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA
- Diabetes Center, University of California, San Francisco, San Francisco, CA, USA
- Medical Scientist Training Program, University of California, San Francisco, San Francisco, CA, USA
- Biomedical Sciences Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - Paige Haas
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, USA
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA, USA
- Institute for Virology and Immunology, J. David Gladstone Institutes, San Francisco, CA, USA
| | - Jennifer A Doudna
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
- Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA, USA
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Alexander Marson
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA.
- Diabetes Center, University of California, San Francisco, San Francisco, CA, USA.
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA.
- Department of Medicine, University of California, San Francisco, CA, USA.
- UCSF Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA, USA.
- Chan Zuckerberg Biohub, San Francisco, CA, USA.
| | - Nevan J Krogan
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, USA.
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA, USA.
- Institute for Virology and Immunology, J. David Gladstone Institutes, San Francisco, CA, USA.
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18
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Chen L, Keppler OT, Schölz C. Post-translational Modification-Based Regulation of HIV Replication. Front Microbiol 2018; 9:2131. [PMID: 30254620 PMCID: PMC6141784 DOI: 10.3389/fmicb.2018.02131] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 08/20/2018] [Indexed: 12/13/2022] Open
Abstract
Human immunodeficiency virus (HIV) relies heavily on the host cellular machinery for production of viral progeny. To exploit cellular proteins for replication and to overcome host factors with antiviral activity, HIV has evolved a set of regulatory and accessory proteins to shape an optimized environment for its replication and to facilitate evasion from the immune system. Several cellular pathways are hijacked by the virus to modulate critical steps during the viral life cycle. Thereby, post-translational modifications (PTMs) of viral and cellular proteins gain increasingly attention as modifying enzymes regulate virtually every step of the viral replication cycle. This review summarizes the current knowledge of HIV-host interactions influenced by PTMs with a special focus on acetylation, ubiquitination, and phosphorylation of proteins linked to cellular signaling and viral replication. Insights into these interactions are surmised to aid development of new intervention strategies.
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Affiliation(s)
- Lin Chen
- Max von Pettenkofer-Institute and Gene Center, Virology, National Reference Center for Retroviruses, Faculty of Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Oliver T Keppler
- Max von Pettenkofer-Institute and Gene Center, Virology, National Reference Center for Retroviruses, Faculty of Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Christian Schölz
- Max von Pettenkofer-Institute and Gene Center, Virology, National Reference Center for Retroviruses, Faculty of Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
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19
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Zhao XZ, Métifiot M, Kiselev E, Kessl JJ, Maddali K, Marchand C, Kvaratskhelia M, Pommier Y, Burke TR. HIV-1 Integrase-Targeted Short Peptides Derived from a Viral Protein R Sequence. Molecules 2018; 23:molecules23081858. [PMID: 30049955 PMCID: PMC6222646 DOI: 10.3390/molecules23081858] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 07/18/2018] [Accepted: 07/23/2018] [Indexed: 01/28/2023] Open
Abstract
HIV-1 integrase (IN) inhibitors represent a new class of highly effective anti-AIDS therapeutics. Current FDA-approved IN strand transfer inhibitors (INSTIs) share a common mechanism of action that involves chelation of catalytic divalent metal ions. However, the emergence of IN mutants having reduced sensitivity to these inhibitors underlies efforts to derive agents that antagonize IN function by alternate mechanisms. Integrase along with the 96-residue multifunctional accessory protein, viral protein R (Vpr), are both components of the HIV-1 pre-integration complex (PIC). Coordinated interactions within the PIC are important for viral replication. Herein, we report a 7-mer peptide based on the shortened Vpr (69–75) sequence containing a biotin group and a photo-reactive benzoylphenylalanyl residue, and which exhibits low micromolar IN inhibitory potency. Photo-crosslinking experiments have indicated that the peptide directly binds IN. The peptide does not interfere with IN-DNA interactions or induce higher-order, aberrant IN multimerization, suggesting a mode of action for the peptide that is distinct from clinically used INSTIs and developmental allosteric IN inhibitors. This compact Vpr-derived peptide may serve as a valuable pharmacological tool to identify a potential new pharmacologic site.
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Affiliation(s)
- Xue Zhi Zhao
- Chemical Biology Laboratory, Center of Cancer Research, Frederick, MD 21702, USA.
| | - Mathieu Métifiot
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Evgeny Kiselev
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Jacques J Kessl
- College of Pharmacy and Center for Retrovirus Research, The Ohio State University, Columbus, OH 43210, USA.
- Department of Chemistry and Biochemistry, The University of Southern Mississippi, Hattiesburg, MS 39406, USA.
| | - Kasthuraiah Maddali
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Christophe Marchand
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Mamuka Kvaratskhelia
- College of Pharmacy and Center for Retrovirus Research, The Ohio State University, Columbus, OH 43210, USA.
- Division of Infectious Diseases, University of Colorado School of Medicine, Aurora, CO 80045, USA.
| | - Yves Pommier
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Terrence R Burke
- Chemical Biology Laboratory, Center of Cancer Research, Frederick, MD 21702, USA.
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20
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Engelman AN, Singh PK. Cellular and molecular mechanisms of HIV-1 integration targeting. Cell Mol Life Sci 2018; 75:2491-2507. [PMID: 29417178 PMCID: PMC6004233 DOI: 10.1007/s00018-018-2772-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 01/23/2018] [Accepted: 02/01/2018] [Indexed: 12/21/2022]
Abstract
Integration is central to HIV-1 replication and helps mold the reservoir of cells that persists in AIDS patients. HIV-1 interacts with specific cellular factors to target integration to interior regions of transcriptionally active genes within gene-dense regions of chromatin. The viral capsid interacts with several proteins that are additionally implicated in virus nuclear import, including cleavage and polyadenylation specificity factor 6, to suppress integration into heterochromatin. The viral integrase protein interacts with transcriptional co-activator lens epithelium-derived growth factor p75 to principally position integration within gene bodies. The integrase additionally senses target DNA distortion and nucleotide sequence to help fine-tune the specific phosphodiester bonds that are cleaved at integration sites. Research into virus-host interactions that underlie HIV-1 integration targeting has aided the development of a novel class of integrase inhibitors and may help to improve the safety of viral-based gene therapy vectors.
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Affiliation(s)
- Alan N Engelman
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, 450 Brookline Avenue, CLS-1010, Boston, MA, 02215, USA.
- Department of Medicine, Harvard Medical School, A-111, 25 Shattuck Street, Boston, MA, 02115, USA.
| | - Parmit K Singh
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, 450 Brookline Avenue, CLS-1010, Boston, MA, 02215, USA
- Department of Medicine, Harvard Medical School, A-111, 25 Shattuck Street, Boston, MA, 02115, USA
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21
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Properties and Functions of Feline Immunodeficiency Virus Gag Domains in Virion Assembly and Budding. Viruses 2018; 10:v10050261. [PMID: 29772651 PMCID: PMC5977254 DOI: 10.3390/v10050261] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 05/13/2018] [Accepted: 05/14/2018] [Indexed: 01/11/2023] Open
Abstract
Feline immunodeficiency virus (FIV) is an important cat pathogen worldwide whose biological and pathophysiological properties resemble those of human immunodeficiency virus type 1 (HIV-1). Therefore, the study of FIV not only benefits its natural host but is also useful for the development of antiviral strategies directed against HIV-1 infections in humans. FIV assembly results from the multimerization of a single but complex viral polypeptide, the Gag precursor. In this review, we will first give an overview of the current knowledge of the proteins encoded by the FIV pol, env, rev, vif, and orf-A genes, and then we will describe and discuss in detail the critical roles that each of the FIV Gag domains plays in virion morphogenesis. Since retroviral assembly is an attractive target for therapeutic interventions, gaining a better understanding of this process is highly desirable.
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Abstract
Replication-defective retroviral vectors have been used for more than 25 years as a tool for efficient and stable insertion of therapeutic transgenes in human cells. Patients suffering from severe genetic diseases have been successfully treated by transplantation of autologous hematopoietic stem-progenitor cells (HSPCs) transduced with retroviral vectors, and the first of this class of therapies, Strimvelis, has recently received market authorization in Europe. Some clinical trials, however, resulted in severe adverse events caused by vector-induced proto-oncogene activation, which showed that retroviral vectors may retain a genotoxic potential associated to proviral integration in the human genome. The adverse events sparked a renewed interest in the biology of retroviruses, which led in a few years to a remarkable understanding of the molecular mechanisms underlying retroviral integration site selection within mammalian genomes. This review summarizes the current knowledge on retrovirus-host interactions at the genomic level, and the peculiar mechanisms by which different retroviruses, and their related gene transfer vectors, integrate in, and interact with, the human genome. This knowledge provides the basis for the development of safer and more efficacious retroviral vectors for human gene therapy.
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Affiliation(s)
| | - Fulvio Mavilio
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy
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23
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A Cas9 Ribonucleoprotein Platform for Functional Genetic Studies of HIV-Host Interactions in Primary Human T Cells. Cell Rep 2017; 17:1438-1452. [PMID: 27783955 DOI: 10.1016/j.celrep.2016.09.080] [Citation(s) in RCA: 134] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 07/28/2016] [Accepted: 09/22/2016] [Indexed: 12/26/2022] Open
Abstract
New genetic tools are needed to understand the functional interactions between HIV and human host factors in primary cells. We recently developed a method to edit the genome of primary CD4+ T cells by electroporation of CRISPR/Cas9 ribonucleoproteins (RNPs). Here, we adapted this methodology to a high-throughput platform for the efficient, arrayed editing of candidate host factors. CXCR4 or CCR5 knockout cells generated with this method are resistant to HIV infection in a tropism-dependent manner, whereas knockout of LEDGF or TNPO3 results in a tropism-independent reduction in infection. CRISPR/Cas9 RNPs can furthermore edit multiple genes simultaneously, enabling studies of interactions among multiple host and viral factors. Finally, in an arrayed screen of 45 genes associated with HIV integrase, we identified several candidate dependency/restriction factors, demonstrating the power of this approach as a discovery platform. This technology should accelerate target validation for pharmaceutical and cell-based therapies to cure HIV infection.
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Abstract
Advances in technology have made it possible to analyze integration sites in cells from HIV-infected patients. A significant fraction of infected cells in patients on long-term therapy are clonally expanded; in some cases the integrated viral DNA contributes to the clonal expansion of the infected cells. Although the large majority (>95%) of the HIV proviruses in treated patients are defective, expanded clones can carry replication-competent proviruses, and cells from these clones can release infectious virus. As discussed in this Perspective, it is likely that cells that produce virus are strongly selected against in vivo, and cells with replication competent proviruses expand and survive because only a small fraction of the cells produce virus. These findings have implications for strategies that are intended to eliminate the reservoir of infected cells that has made it almost impossible to cure HIV-infected patients.
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Affiliation(s)
- Stephen H Hughes
- HIV Drug Resistance Program, National Cancer Institute, Frederick, MD 21702, USA.
| | - John M Coffin
- Department of Molecular Biology and Microbiology, Tufts University, Boston, MA 02111, USA
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25
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George A, Raghavendra NK. L368F/V408F double mutant of IBD of LEDGF/p75 retains interaction with M178I mutant of HIV-1 integrase. Biochem Biophys Res Commun 2017; 490:271-275. [DOI: 10.1016/j.bbrc.2017.06.035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 06/09/2017] [Indexed: 01/15/2023]
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Matysiak J, Lesbats P, Mauro E, Lapaillerie D, Dupuy JW, Lopez AP, Benleulmi MS, Calmels C, Andreola ML, Ruff M, Llano M, Delelis O, Lavigne M, Parissi V. Modulation of chromatin structure by the FACT histone chaperone complex regulates HIV-1 integration. Retrovirology 2017; 14:39. [PMID: 28754126 PMCID: PMC5534098 DOI: 10.1186/s12977-017-0363-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 07/24/2017] [Indexed: 01/23/2023] Open
Abstract
Background Insertion of retroviral genome DNA occurs in the chromatin of the host cell. This step is modulated by chromatin structure as nucleosomes compaction was shown to prevent HIV-1 integration and chromatin remodeling has been reported to affect integration efficiency. LEDGF/p75-mediated targeting of the integration complex toward RNA polymerase II (polII) transcribed regions ensures optimal access to dynamic regions that are suitable for integration. Consequently, we have investigated the involvement of polII-associated factors in the regulation of HIV-1 integration. Results Using a pull down approach coupled with mass spectrometry, we have selected the FACT (FAcilitates Chromatin Transcription) complex as a new potential cofactor of HIV-1 integration. FACT is a histone chaperone complex associated with the polII transcription machinery and recently shown to bind LEDGF/p75. We report here that a tripartite complex can be formed between HIV-1 integrase, LEDGF/p75 and FACT in vitro and in cells. Biochemical analyzes show that FACT-dependent nucleosome disassembly promotes HIV-1 integration into chromatinized templates, and generates highly favored nucleosomal structures in vitro. This effect was found to be amplified by LEDGF/p75. Promotion of this FACT-mediated chromatin remodeling in cells both increases chromatin accessibility and stimulates HIV-1 infectivity and integration. Conclusions Altogether, our data indicate that FACT regulates HIV-1 integration by inducing local nucleosomes dissociation that modulates the functional association between the incoming intasome and the targeted nucleosome. Electronic supplementary material The online version of this article (doi:10.1186/s12977-017-0363-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Julien Matysiak
- Fundamental Microbiology and Pathogenicity Laboratory, UMR 5234 CNRS, University of Bordeaux, SFR TransBioMed, 146 rue Léo Saignat, 33076, Bordeaux Cedex, France.,International Associated Laboratory (LIA) of Microbiology and Immunology, CNRS/University de Bordeaux/Heinrich Pette Institute-Leibniz Institute for Experimental Virology, Bordeaux, France
| | - Paul Lesbats
- Fundamental Microbiology and Pathogenicity Laboratory, UMR 5234 CNRS, University of Bordeaux, SFR TransBioMed, 146 rue Léo Saignat, 33076, Bordeaux Cedex, France.,International Associated Laboratory (LIA) of Microbiology and Immunology, CNRS/University de Bordeaux/Heinrich Pette Institute-Leibniz Institute for Experimental Virology, Bordeaux, France
| | - Eric Mauro
- Fundamental Microbiology and Pathogenicity Laboratory, UMR 5234 CNRS, University of Bordeaux, SFR TransBioMed, 146 rue Léo Saignat, 33076, Bordeaux Cedex, France.,International Associated Laboratory (LIA) of Microbiology and Immunology, CNRS/University de Bordeaux/Heinrich Pette Institute-Leibniz Institute for Experimental Virology, Bordeaux, France
| | - Delphine Lapaillerie
- Fundamental Microbiology and Pathogenicity Laboratory, UMR 5234 CNRS, University of Bordeaux, SFR TransBioMed, 146 rue Léo Saignat, 33076, Bordeaux Cedex, France.,International Associated Laboratory (LIA) of Microbiology and Immunology, CNRS/University de Bordeaux/Heinrich Pette Institute-Leibniz Institute for Experimental Virology, Bordeaux, France.,Viral DNA Integration and Chromatin Dynamics Network (DyNAVir), Paris, France
| | - Jean-William Dupuy
- Centre Génomique fonctionnelle Bordeaux, Plateforme Proteome, Université de Bordeaux, Bordeaux, France
| | - Angelica P Lopez
- Department of Biological Sciences, University of Texas at El Paso, El Paso, TX, USA
| | - Mohamed Salah Benleulmi
- Fundamental Microbiology and Pathogenicity Laboratory, UMR 5234 CNRS, University of Bordeaux, SFR TransBioMed, 146 rue Léo Saignat, 33076, Bordeaux Cedex, France.,International Associated Laboratory (LIA) of Microbiology and Immunology, CNRS/University de Bordeaux/Heinrich Pette Institute-Leibniz Institute for Experimental Virology, Bordeaux, France.,Viral DNA Integration and Chromatin Dynamics Network (DyNAVir), Paris, France
| | - Christina Calmels
- Fundamental Microbiology and Pathogenicity Laboratory, UMR 5234 CNRS, University of Bordeaux, SFR TransBioMed, 146 rue Léo Saignat, 33076, Bordeaux Cedex, France.,International Associated Laboratory (LIA) of Microbiology and Immunology, CNRS/University de Bordeaux/Heinrich Pette Institute-Leibniz Institute for Experimental Virology, Bordeaux, France.,Viral DNA Integration and Chromatin Dynamics Network (DyNAVir), Paris, France
| | - Marie-Line Andreola
- Fundamental Microbiology and Pathogenicity Laboratory, UMR 5234 CNRS, University of Bordeaux, SFR TransBioMed, 146 rue Léo Saignat, 33076, Bordeaux Cedex, France.,International Associated Laboratory (LIA) of Microbiology and Immunology, CNRS/University de Bordeaux/Heinrich Pette Institute-Leibniz Institute for Experimental Virology, Bordeaux, France.,Viral DNA Integration and Chromatin Dynamics Network (DyNAVir), Paris, France
| | - Marc Ruff
- Département de Biologie Structurale Intégrative, UDS, U596 INSERM, UMR7104 CNRS, IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), Illkirch-Graffenstaden, France
| | - Manuel Llano
- Department of Biological Sciences, University of Texas at El Paso, El Paso, TX, USA
| | - Olivier Delelis
- LBPA, UMR8113, CNRS, ENS-Cachan, Cachan, France.,Viral DNA Integration and Chromatin Dynamics Network (DyNAVir), Paris, France
| | - Marc Lavigne
- Department of Virology, UMR 3569, CNRS, Institut Pasteur, Paris, France.,Institut Cochin-INSERM U1016-CNRS UMR8104, Université Paris Descartes, Paris, France.,Viral DNA Integration and Chromatin Dynamics Network (DyNAVir), Paris, France
| | - Vincent Parissi
- Fundamental Microbiology and Pathogenicity Laboratory, UMR 5234 CNRS, University of Bordeaux, SFR TransBioMed, 146 rue Léo Saignat, 33076, Bordeaux Cedex, France. .,International Associated Laboratory (LIA) of Microbiology and Immunology, CNRS/University de Bordeaux/Heinrich Pette Institute-Leibniz Institute for Experimental Virology, Bordeaux, France. .,Viral DNA Integration and Chromatin Dynamics Network (DyNAVir), Paris, France.
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27
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Mullins JI, Frenkel LM. Clonal Expansion of Human Immunodeficiency Virus-Infected Cells and Human Immunodeficiency Virus Persistence During Antiretroviral Therapy. J Infect Dis 2017; 215:S119-S127. [PMID: 28520966 DOI: 10.1093/infdis/jiw636] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The latent HIV-1 reservoir in blood decays very slowly, even during prolonged suppression of viral replication by antiretroviral therapy (ART). Mechanisms for reservoir persistence include replenishment through low-level viral replication, longevity and homeostatic proliferation of memory T cells, and most recently appreciated, clonal expansion of HIV-infected cells. Clonally expanded cells make up a large and increasing fraction of the residual infected cell population on ART, and insertion of HIV proviruses into certain host cellular genes has been associated with this proliferation. That the vast majority of proviruses are defective clouds our assessment of the degree to which clonally expanded cells harbor infectious viruses, and thus the extent to which they contribute to reservoirs relevant to curing infection. This review summarizes past studies that have defined our current understanding and the gaps in our knowledge of the mechanisms by which proviral integration and clonal expansion sustain the HIV reservoir.
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Affiliation(s)
- James I Mullins
- Departments of Microbiology, Medicine, Global Health and Laboratory Medicine, University of Washington, Seattle, WA, US
| | - Lisa M Frenkel
- Departments of Pediatrics, Medicine, Global Health and Laboratory Medicine, University of Washington, Seattle, WA, US.,Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, US
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28
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Abstract
The interactions between a retrovirus and host cell chromatin that underlie integration and provirus expression are poorly understood. The prototype foamy virus (PFV) structural protein GAG associates with chromosomes via a chromatin-binding sequence (CBS) located within its C-terminal region. Here, we show that the PFV CBS is essential and sufficient for a direct interaction with nucleosomes and present a crystal structure of the CBS bound to a mononucleosome. The CBS interacts with the histone octamer, engaging the H2A-H2B acidic patch in a manner similar to other acidic patch-binding proteins such as herpesvirus latency-associated nuclear antigen (LANA). Substitutions of the invariant arginine anchor residue in GAG result in global redistribution of PFV and macaque simian foamy virus (SFVmac) integration sites toward centromeres, dampening the resulting proviral expression without affecting the overall efficiency of integration. Our findings underscore the importance of retroviral structural proteins for integration site selection and the avoidance of genomic junkyards.
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29
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Grawenhoff J, Engelman AN. Retroviral integrase protein and intasome nucleoprotein complex structures. World J Biol Chem 2017; 8:32-44. [PMID: 28289517 PMCID: PMC5329712 DOI: 10.4331/wjbc.v8.i1.32] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 12/24/2016] [Accepted: 01/14/2017] [Indexed: 02/05/2023] Open
Abstract
Retroviral replication proceeds through the integration of a DNA copy of the viral RNA genome into the host cellular genome, a process that is mediated by the viral integrase (IN) protein. IN catalyzes two distinct chemical reactions: 3’-processing, whereby the viral DNA is recessed by a di- or trinucleotide at its 3’-ends, and strand transfer, in which the processed viral DNA ends are inserted into host chromosomal DNA. Although IN has been studied as a recombinant protein since the 1980s, detailed structural understanding of its catalytic functions awaited high resolution structures of functional IN-DNA complexes or intasomes, initially obtained in 2010 for the spumavirus prototype foamy virus (PFV). Since then, two additional retroviral intasome structures, from the α-retrovirus Rous sarcoma virus (RSV) and β-retrovirus mouse mammary tumor virus (MMTV), have emerged. Here, we briefly review the history of IN structural biology prior to the intasome era, and then compare the intasome structures of PFV, MMTV and RSV in detail. Whereas the PFV intasome is characterized by a tetrameric assembly of IN around the viral DNA ends, the newer structures harbor octameric IN assemblies. Although the higher order architectures of MMTV and RSV intasomes differ from that of the PFV intasome, they possess remarkably similar intasomal core structures. Thus, retroviral integration machineries have adapted evolutionarily to utilize disparate IN elements to construct convergent intasome core structures for catalytic function.
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30
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Retargeted Foamy Virus Vectors Integrate Less Frequently Near Proto-oncogenes. Sci Rep 2016; 6:36610. [PMID: 27812034 PMCID: PMC5095648 DOI: 10.1038/srep36610] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 10/17/2016] [Indexed: 12/17/2022] Open
Abstract
Retroviral gene therapy offers immense potential to treat many genetic diseases and has already shown efficacy in clinical trials. However, retroviral vector mediated genotoxicity remains a major challenge and clinically relevant approaches to reduce integration near genes and proto-oncogenes are needed. Foamy retroviral vectors have several advantages over gammaretroviral and lentiviral vectors including a potentially safer integration profile and a lower propensity to activate nearby genes. Here we successfully retargeted foamy retroviral vectors away from genes and into satellite regions enriched for trimethylated histone H3 at lysine 9 by modifying the foamy virus Gag and Pol proteins. Retargeted foamy retroviral vectors integrated near genes and proto-oncogenes less often (p < 0.001) than controls. Importantly, retargeted foamy retroviral vectors can be produced at high, clinically relevant titers (>107 transducing units/ml), and unlike other reported retargeting approaches engineered target cells are not needed to achieve retargeting. As proof of principle for use in the clinic we show efficient transduction and retargeting in human cord blood CD34+ cells. The modified Gag and Pol helper constructs we describe will allow any investigator to simply use these helper plasmids during vector production to retarget therapeutic foamy retroviral vectors.
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31
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Yang D, Liao R, Zheng Y, Sun L, Xu T. Analysis of PBase Binding Profile Indicates an Insertion Target Selection Mechanism Dependent on TTAA, But Not Transcriptional Activity. Int J Biol Sci 2016; 12:1074-82. [PMID: 27570481 PMCID: PMC4997051 DOI: 10.7150/ijbs.15589] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2016] [Accepted: 05/15/2016] [Indexed: 12/20/2022] Open
Abstract
Transposons and retroviruses are important pathogenic agents and tools for mutagenesis and transgenesis. Insertion target selection is a key feature for a given transposon or retrovirus. The piggyBac (PB) transposon is highly active in mice and human cells, which has a much better genome-wide distribution compared to the retrovirus and P-element. However, the underlying reason is not clear. Utilizing a tagged functional PB transposase (PBase), we were able to conduct genome-wide profiling for PBase binding sites in the mouse genome. We have shown that PBase binding mainly depends on the distribution of the tetranucleotide TTAA, which is not affected by the presence of PB DNA. Furthermore, PBase binding is negatively influenced by the methylation of CG sites in the genome. Analysis of a large collection of PB insertions in mice has revealed an insertion profile similar to the PBase binding profile. Interestingly, this profile is not correlated with transcriptional active genes in the genome or transcriptionally active regions within a transcriptional unit. This differs from what has been previously shown for P-element and retroviruses insertions. Our study provides an explanation for PB's genome-wide insertion distribution and also suggests that PB target selection relies on a new mechanism independent of active transcription and open chromatin structure.
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Affiliation(s)
- Dong Yang
- 1. State Key Laboratory of Genetic Engineering and National Center for International Research of Development and Disease, Fudan-Yale Center for Biomedical Research, Innovation Center for International Cooperation of Genetics and Development, Institute of Developmental Biology and Molecular Medicine, School of Life Sciences, Fudan University, Shanghai 200433; 2. Howard Hughes Medical Institute, Department of Genetics, Yale University School of Medicine, New Haven, CT 06536
| | - Ruiqi Liao
- 1. State Key Laboratory of Genetic Engineering and National Center for International Research of Development and Disease, Fudan-Yale Center for Biomedical Research, Innovation Center for International Cooperation of Genetics and Development, Institute of Developmental Biology and Molecular Medicine, School of Life Sciences, Fudan University, Shanghai 200433
| | - Yun Zheng
- 3. Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan 650500, China
| | - Ling Sun
- 1. State Key Laboratory of Genetic Engineering and National Center for International Research of Development and Disease, Fudan-Yale Center for Biomedical Research, Innovation Center for International Cooperation of Genetics and Development, Institute of Developmental Biology and Molecular Medicine, School of Life Sciences, Fudan University, Shanghai 200433
| | - Tian Xu
- 1. State Key Laboratory of Genetic Engineering and National Center for International Research of Development and Disease, Fudan-Yale Center for Biomedical Research, Innovation Center for International Cooperation of Genetics and Development, Institute of Developmental Biology and Molecular Medicine, School of Life Sciences, Fudan University, Shanghai 200433; 2. Howard Hughes Medical Institute, Department of Genetics, Yale University School of Medicine, New Haven, CT 06536
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32
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De Luca L, Agharbaoui FE, Gitto R, Buemi MR, Christ F, Debyser Z, Ferro S. Rational Design, Synthesis and Evaluation of Coumarin Derivatives as Protein-protein Interaction Inhibitors. Mol Inform 2016; 35:460-73. [DOI: 10.1002/minf.201501034] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 06/01/2016] [Indexed: 01/28/2023]
Affiliation(s)
- Laura De Luca
- Dipartimento di Scienze Chimiche, Biologiche; Farmaceutiche ed Ambientali; Università degli Studi di Messina; Viale Annunziata I-98168 Messina Italy
| | - Fatima E. Agharbaoui
- Dipartimento di Scienze Chimiche, Biologiche; Farmaceutiche ed Ambientali; Università degli Studi di Messina; Viale Annunziata I-98168 Messina Italy
| | - Rosaria Gitto
- Dipartimento di Scienze Chimiche, Biologiche; Farmaceutiche ed Ambientali; Università degli Studi di Messina; Viale Annunziata I-98168 Messina Italy
| | - Maria Rosa Buemi
- Dipartimento di Scienze Chimiche, Biologiche; Farmaceutiche ed Ambientali; Università degli Studi di Messina; Viale Annunziata I-98168 Messina Italy
| | - Frauke Christ
- Molecular Virology and Gene Therapy KU Leuven and IRC KULAK; Kapucijnenvoer 33 B-3000 Leuven, Flanders Belgium
| | - Zeger Debyser
- Molecular Virology and Gene Therapy KU Leuven and IRC KULAK; Kapucijnenvoer 33 B-3000 Leuven, Flanders Belgium
| | - Stefania Ferro
- Dipartimento di Scienze Chimiche, Biologiche; Farmaceutiche ed Ambientali; Università degli Studi di Messina; Viale Annunziata I-98168 Messina Italy
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33
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Lopez AP, Kugelman JR, Garcia-Rivera J, Urias E, Salinas SA, Fernandez-Zapico ME, Llano M. The Structure-Specific Recognition Protein 1 Associates with Lens Epithelium-Derived Growth Factor Proteins and Modulates HIV-1 Replication. J Mol Biol 2016; 428:2814-31. [PMID: 27216501 DOI: 10.1016/j.jmb.2016.05.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 04/21/2016] [Accepted: 05/16/2016] [Indexed: 10/21/2022]
Abstract
The lens epithelium-derived growth factor p75 (LEDGF/p75) is a chromatin-bound protein essential for efficient lentiviral integration. Genome-wide studies have located LEDGF/p75 inside actively transcribed genes where it mediates lentiviral integration. Although its role in HIV-1 integration is clearly established, the role of LEDGF/p75-associated proteins in HIV-1 infection remains unexplored. Using protein-protein interaction assays, we demonstrated that LEDGF/p75 complexes with a chromatin-remodeling complex facilitates chromatin transcription (FACT), a heterodimer of the structure-specific recognition protein 1 (SSRP1) and the human homolog of suppressor of Ty 16 (hSpt16). Detailed analysis of the interaction of LEDGF/p75 with the FACT complex indicates that LEDGF/p75 interacts with SSRP1 in an hSpt16-independent manner that requires the PWWP domain of LEDGF proteins and the HMG domain of SSRP1. Functional characterizations demonstrate a LEDGF/p75-independent role of SSRP1 in the regulation of HIV-1 replication. shRNA-mediated partial knockdown of SSRP1 reduces HIV-1 infection, but not Murine Leukemia Virus, in human CD4(+) T cells. Similarly, SSRP1 knockdown affects infection by HIV-1-derived viruses that express genes from the viral LTR but not from an internal immediate-early CMV promoter, suggesting a role of SSRP1 in LTR-driven gene expression but not in viral DNA integration. Together, our data demonstrate for the first time the association of LEDGF proteins with the FACT complex and give further support to a role of SSRP1 in HIV-1 infection.
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Affiliation(s)
- Angelica P Lopez
- Department of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968, USA
| | - Jeffrey R Kugelman
- Department of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968, USA
| | - Jose Garcia-Rivera
- Department of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968, USA
| | - Eduardo Urias
- Department of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968, USA
| | - Sandra A Salinas
- Department of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968, USA
| | | | - Manuel Llano
- Department of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968, USA.
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34
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Abstract
The integration of a DNA copy of the viral RNA genome into host chromatin is the defining step of retroviral replication. This enzymatic process is catalyzed by the virus-encoded integrase protein, which is conserved among retroviruses and LTR-retrotransposons. Retroviral integration proceeds via two integrase activities: 3'-processing of the viral DNA ends, followed by the strand transfer of the processed ends into host cell chromosomal DNA. Herein we review the molecular mechanism of retroviral DNA integration, with an emphasis on reaction chemistries and architectures of the nucleoprotein complexes involved. We additionally discuss the latest advances on anti-integrase drug development for the treatment of AIDS and the utility of integrating retroviral vectors in gene therapy applications.
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Affiliation(s)
- Paul Lesbats
- Clare Hall Laboratories, The Francis Crick Institute , Blanche Lane, South Mimms, EN6 3LD, U.K
| | - Alan N Engelman
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute and Department of Medicine, Harvard Medical School , 450 Brookline Avenue, Boston, Massachusetts 02215 United States
| | - Peter Cherepanov
- Clare Hall Laboratories, The Francis Crick Institute , Blanche Lane, South Mimms, EN6 3LD, U.K.,Imperial College London , St-Mary's Campus, Norfolk Place, London, W2 1PG, U.K
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35
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A critical role for alternative polyadenylation factor CPSF6 in targeting HIV-1 integration to transcriptionally active chromatin. Proc Natl Acad Sci U S A 2016; 113:E1054-63. [PMID: 26858452 DOI: 10.1073/pnas.1524213113] [Citation(s) in RCA: 169] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Integration is vital to retroviral replication and influences the establishment of the latent HIV reservoir. HIV-1 integration favors active genes, which is in part determined by the interaction between integrase and lens epithelium-derived growth factor (LEDGF)/p75. Because gene targeting remains significantly enriched, relative to random in LEDGF/p75 deficient cells, other host factors likely contribute to gene-tropic integration. Nucleoporins 153 and 358, which bind HIV-1 capsid, play comparatively minor roles in integration targeting, but the influence of another capsid binding protein, cleavage and polyadenylation specificity factor 6 (CPSF6), has not been reported. In this study we knocked down or knocked out CPSF6 in parallel or in tandem with LEDGF/p75. CPSF6 knockout changed viral infectivity kinetics, decreased proviral formation, and preferentially decreased integration into transcriptionally active genes, spliced genes, and regions of chromatin enriched in genes and activating histone modifications. LEDGF/p75 depletion by contrast preferentially altered positional integration targeting within gene bodies. Dual factor knockout reduced integration into genes to below the levels observed with either single knockout and revealed that CPSF6 played a more dominant role than LEDGF/p75 in directing integration to euchromatin. CPSF6 complementation rescued HIV-1 integration site distribution in CPSF6 knockout cells, but complementation with a capsid binding mutant of CPSF6 did not. We conclude that integration targeting proceeds via two distinct mechanisms: capsid-CPSF6 binding directs HIV-1 to actively transcribed euchromatin, where the integrase-LEDGF/p75 interaction drives integration into gene bodies.
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36
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Abstract
The persistence of human immunodeficiency virus type 1 (HIV-1) in latent reservoirs is a major barrier to HIV cure. Reservoir establishment depends on low viral expression that may be related to provirus integration sites (IS). In vitro, in cell lines and primary T cells, latency is associated with specific IS through reduced viral expression mediated by transcriptional interference by host cellular promoters, reverse orientation, and the presence of specific epigenetic modifiers. In primary T cell models of latency, specific IS are associated with intracellular viral antigen expression that is not directly related to cell activation. In contrast, in patient CD4+ T cells, there is enrichment for IS in genes controlling cell cycle and survival and in some clonally expanded T cell subpopulations. Multiple insertion sites within some specific genes may suggest that integrated HIV can increase the host’s T cell survival.
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Affiliation(s)
- Simin D. Rezaei
- Faculty of Medicine, Dentistry and Health Sciences, Department of Microbiology and Immunology, Doherty Institute for Infection and Immunity, The University of Melbourne, 4th Floor, 786-798 Elizabeth St, Melbourne, 3010 Australia
| | - Paul U. Cameron
- Faculty of Medicine, Dentistry and Health Sciences, Department of Microbiology and Immunology, Doherty Institute for Infection and Immunity, The University of Melbourne, 4th Floor, 786-798 Elizabeth St, Melbourne, 3010 Australia
- Infectious Diseases Unit, Department of Infectious Diseases, Alfred Hospital, 85 Commercial Rd, Melbourne, Victoria 3004 Australia
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37
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Singh PK, Plumb MR, Ferris AL, Iben JR, Wu X, Fadel HJ, Luke BT, Esnault C, Poeschla EM, Hughes SH, Kvaratskhelia M, Levin HL. LEDGF/p75 interacts with mRNA splicing factors and targets HIV-1 integration to highly spliced genes. Genes Dev 2015; 29:2287-97. [PMID: 26545813 PMCID: PMC4647561 DOI: 10.1101/gad.267609.115] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 10/09/2015] [Indexed: 12/22/2022]
Abstract
The host chromatin-binding factor LEDGF/p75 interacts with HIV-1 integrase and directs integration to active transcription units. To understand how LEDGF/p75 recognizes transcription units, we sequenced 1 million HIV-1 integration sites isolated from cultured HEK293T cells. Analysis of integration sites showed that cancer genes were preferentially targeted, raising concerns about using lentivirus vectors for gene therapy. Additional analysis led to the discovery that introns and alternative splicing contributed significantly to integration site selection. These correlations were independent of transcription levels, size of transcription units, and length of the introns. Multivariate analysis with five parameters previously found to predict integration sites showed that intron density is the strongest predictor of integration density in transcription units. Analysis of previously published HIV-1 integration site data showed that integration density in transcription units in mouse embryonic fibroblasts also correlated strongly with intron number, and this correlation was absent in cells lacking LEDGF. Affinity purification showed that LEDGF/p75 is associated with a number of splicing factors, and RNA sequencing (RNA-seq) analysis of HEK293T cells lacking LEDGF/p75 or the LEDGF/p75 integrase-binding domain (IBD) showed that LEDGF/p75 contributes to splicing patterns in half of the transcription units that have alternative isoforms. Thus, LEDGF/p75 interacts with splicing factors, contributes to exon choice, and directs HIV-1 integration to transcription units that are highly spliced.
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Affiliation(s)
- Parmit Kumar Singh
- Section on Eukaryotic Transposable Elements, Program in Cellular Regulation and Metabolism, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Matthew R Plumb
- Center for Retrovirus Research, College of Pharmacy, The Ohio State University, Columbus, Ohio 43210, USA
| | - Andrea L Ferris
- HIV Drug Resistance Program, National Cancer Institute, Frederick, Maryland 21702, USA
| | - James R Iben
- Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute for Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Xiaolin Wu
- Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, USA
| | - Hind J Fadel
- Department of Molecular Medicine, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA
| | - Brian T Luke
- Advanced Biomedical Computing Center, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, 21702, USA
| | - Caroline Esnault
- Section on Eukaryotic Transposable Elements, Program in Cellular Regulation and Metabolism, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Eric M Poeschla
- Division of Infectious Diseases, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Stephen H Hughes
- HIV Drug Resistance Program, National Cancer Institute, Frederick, Maryland 21702, USA
| | - Mamuka Kvaratskhelia
- Center for Retrovirus Research, College of Pharmacy, The Ohio State University, Columbus, Ohio 43210, USA
| | - Henry L Levin
- Section on Eukaryotic Transposable Elements, Program in Cellular Regulation and Metabolism, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
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38
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Serrao E, Engelman AN. Sites of retroviral DNA integration: From basic research to clinical applications. Crit Rev Biochem Mol Biol 2015; 51:26-42. [PMID: 26508664 DOI: 10.3109/10409238.2015.1102859] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
One of the most crucial steps in the life cycle of a retrovirus is the integration of the viral DNA (vDNA) copy of the RNA genome into the genome of an infected host cell. Integration provides for efficient viral gene expression as well as for the segregation of viral genomes to daughter cells upon cell division. Some integrated viruses are not well expressed, and cells latently infected with human immunodeficiency virus type 1 (HIV-1) can resist the action of potent antiretroviral drugs and remain dormant for decades. Intensive research has been dedicated to understanding the catalytic mechanism of integration, as well as the viral and cellular determinants that influence integration site distribution throughout the host genome. In this review, we summarize the evolution of techniques that have been used to recover and map retroviral integration sites, from the early days that first indicated that integration could occur in multiple cellular DNA locations, to current technologies that map upwards of millions of unique integration sites from single in vitro integration reactions or cell culture infections. We further review important insights gained from the use of such mapping techniques, including the monitoring of cell clonal expansion in patients treated with retrovirus-based gene therapy vectors, or patients with acquired immune deficiency syndrome (AIDS) on suppressive antiretroviral therapy (ART). These insights span from integrase (IN) enzyme sequence preferences within target DNA (tDNA) at the sites of integration, to the roles of host cellular proteins in mediating global integration distribution, to the potential relationship between genomic location of vDNA integration site and retroviral latency.
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Affiliation(s)
- Erik Serrao
- a Department of Cancer Immunology and Virology , Dana-Farber Cancer Institute , Boston , MA , USA
| | - Alan N Engelman
- a Department of Cancer Immunology and Virology , Dana-Farber Cancer Institute , Boston , MA , USA
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39
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Bin Hamid F, Kim J, Shin CG. Cellular and viral determinants of retroviral nuclear entry. Can J Microbiol 2015; 62:1-15. [PMID: 26553381 DOI: 10.1139/cjm-2015-0350] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Retroviruses must integrate their cDNA into the host genome to generate proviruses. Viral DNA-protein complexes interact with cellular proteins and produce pre-integration complexes, which carry the viral genome and cross the nuclear pore channel to enter the nucleus and integrate viral DNA into host chromosomal DNA. If the reverse transcripts fail to integrate, linear or circular DNA species such as 1- and 2-long terminal repeats are generated. Such complexes encounter numerous cellular proteins in the cytoplasm, which restrict viral infection and protect the nucleus. To overcome host cell defenses, the pathogens have evolved several evasion strategies. Viral proteins often contain nuclear localization signals, allowing entry into the nucleus. Among more than 1000 proteins identified as required for HIV infection by RNA interference screening, karyopherins, cleavage and polyadenylation specific factor 6, and nucleoporins have been predominantly studied. This review discusses current opinions about the synergistic relationship between the viral and cellular factors involved in nuclear import, with focus on the unveiled mysteries of the host-pathogen interaction, and highlights novel approaches to pinpoint therapeutic targets.
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Affiliation(s)
- Faysal Bin Hamid
- Department of Systems Biotechnology, Chung-Ang University, Ansung 456-756, Republic of Korea.,Department of Systems Biotechnology, Chung-Ang University, Ansung 456-756, Republic of Korea
| | - Jinsun Kim
- Department of Systems Biotechnology, Chung-Ang University, Ansung 456-756, Republic of Korea.,Department of Systems Biotechnology, Chung-Ang University, Ansung 456-756, Republic of Korea
| | - Cha-Gyun Shin
- Department of Systems Biotechnology, Chung-Ang University, Ansung 456-756, Republic of Korea.,Department of Systems Biotechnology, Chung-Ang University, Ansung 456-756, Republic of Korea
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40
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Ochs RL, Mahler M, Basu A, Rios-Colon L, Sanchez TW, Andrade LE, Fritzler MJ, Casiano CA. The significance of autoantibodies to DFS70/LEDGFp75 in health and disease: integrating basic science with clinical understanding. Clin Exp Med 2015; 16:273-93. [PMID: 26088181 PMCID: PMC4684813 DOI: 10.1007/s10238-015-0367-0] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 06/03/2015] [Indexed: 12/16/2022]
Abstract
Antinuclear autoantibodies (ANAs) displaying the nuclear dense fine speckled immunofluorescence (DFS-IIF) pattern in HEp-2 substrates are commonly observed in clinical laboratory referrals. They target the dense fine speckled autoantigen of 70 kD (DFS70), most commonly known as lens epithelium-derived growth factor p75 (LEDGFp75). Interesting features of these ANAs include their low frequency in patients with systemic autoimmune rheumatic diseases (SARD), elevated prevalence in apparently healthy individuals, IgG isotype, strong trend to occur as the only ANA specificity in serum, and occurrence in moderate to high titers. These autoantibodies have also been detected at varied frequencies in patients with diverse non-SARD inflammatory and malignant conditions such as atopic diseases, asthma, eye diseases, and prostate cancer. These observations have recently stimulated vigorous research on their clinical and biological significance. Some studies have suggested that they are natural, protective antibodies that could serve as biomarkers to exclude a SARD diagnosis. Other studies suggest that they might be pathogenic in certain contexts. The emerging role of DFS70/LEDGFp75 as a stress protein relevant to human acquired immunodeficiency syndrome, cancer, and inflammation also points to the possibility that these autoantibodies could be sensors of cellular stress and inflammation associated with environmental factors. In this comprehensive review, we integrate our current knowledge of the biology of DFS70/LEDGFp75 with the clinical understanding of its autoantibodies in the contexts of health and disease.
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Affiliation(s)
- Robert L Ochs
- Ventana Medical, Roche Tissue Diagnostics, Tucson, AZ, USA
| | - Michael Mahler
- Department of Research, Inova Diagnostics, Inc., San Diego, CA, USA
| | - Anamika Basu
- Department of Basic Sciences, Center for Health Disparities and Molecular Medicine, Loma Linda University School of Medicine, Mortensen Hall 142, 11085 Campus St, Loma Linda, CA, 92350, USA
| | - Leslimar Rios-Colon
- Department of Basic Sciences, Center for Health Disparities and Molecular Medicine, Loma Linda University School of Medicine, Mortensen Hall 142, 11085 Campus St, Loma Linda, CA, 92350, USA
| | - Tino W Sanchez
- Department of Basic Sciences, Center for Health Disparities and Molecular Medicine, Loma Linda University School of Medicine, Mortensen Hall 142, 11085 Campus St, Loma Linda, CA, 92350, USA
| | - Luis E Andrade
- Rheumatology Division, Universidade Federal de Sao Paulo, and Immunology Division, Fleury Medicine and Health Laboratories, São Paulo, Brazil
| | | | - Carlos A Casiano
- Department of Basic Sciences, Center for Health Disparities and Molecular Medicine, Loma Linda University School of Medicine, Mortensen Hall 142, 11085 Campus St, Loma Linda, CA, 92350, USA.
- Department of Medicine, Division of Rheumatology, Loma Linda University School of Medicine, Loma Linda, CA, USA.
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41
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Interactions of HIV-1 proteins as targets for developing anti-HIV-1 peptides. Future Med Chem 2015; 7:1055-77. [DOI: 10.4155/fmc.15.46] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Protein–protein interactions (PPI) are essential in every step of the HIV replication cycle. Mapping the interactions between viral and host proteins is a fundamental target for the design and development of new therapeutics. In this review, we focus on rational development of anti-HIV-1 peptides based on mapping viral–host and viral–viral protein interactions all across the HIV-1 replication cycle. We also discuss the mechanism of action, specificity and stability of these peptides, which are designed to inhibit PPI. Some of these peptides are excellent tools to study the mechanisms of PPI in HIV-1 replication cycle and for the development of anti-HIV-1 drug leads that modulate PPI.
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42
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Chromatin organization at the nuclear pore favours HIV replication. Nat Commun 2015; 6:6483. [PMID: 25744187 PMCID: PMC4366494 DOI: 10.1038/ncomms7483] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 02/02/2015] [Indexed: 11/08/2022] Open
Abstract
The molecular mechanisms that allow HIV to integrate into particular sites of the host genome are poorly understood. Here we tested if the nuclear pore complex (NPC) facilitates the targeting of HIV integration by acting on chromatin topology. We show that the integrity of the nuclear side of the NPC, which is mainly composed of Tpr, is not required for HIV nuclear import, but that Nup153 is essential. Depletion of Tpr markedly reduces HIV infectivity, but not the level of integration. HIV integration sites in Tpr-depleted cells are less associated with marks of active genes, consistent with the state of chromatin proximal to the NPC, as analysed by super-resolution microscopy. LEDGF/p75, which promotes viral integration into active genes, stabilizes Tpr at the nuclear periphery and vice versa. Our data support a model in which HIV nuclear import and integration are concerted steps, and where Tpr maintains a chromatin environment favourable for HIV replication.
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43
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Feng L, Larue RC, Slaughter A, Kessl JJ, Kvaratskhelia M. HIV-1 integrase multimerization as a therapeutic target. Curr Top Microbiol Immunol 2015; 389:93-119. [PMID: 25778682 PMCID: PMC4791179 DOI: 10.1007/82_2015_439] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Multimeric HIV-1 integrase (IN) plays an essential, multifunctional role in virus replication and serves as an important therapeutic target. Structural and biochemical studies have revealed the importance of the ordered interplay between IN molecules for its function. In the presence of viral DNA ends, individual IN subunits assemble into a tetramer and form a stable synaptic complex (SSC), which mediates integration of the reverse transcribed HIV-1 genome into chromatin. Cellular chromatin-associated protein LEDGF/p75 engages the IN tetramer in the SSC and directs HIV-1 integration into active genes. A mechanism to deregulate the productive interplay between IN subunits with small molecule inhibitors has recently received considerable attention. Most notably, allosteric IN inhibitors (ALLINIs) have been shown to bind to the IN dimer interface at the LEDGF/p75 binding pocket, stabilize interacting IN subunits, and promote aberrant, higher order IN multimerization. Consequently, these compounds impair formation of the SSC and associated LEDGF/p75-independent IN catalytic activities as well as inhibit LEDGF/p75 binding to the SSC in vitro. However, in infected cells, ALLINIs more potently impaired correct maturation of virus particles than the integration step. ALLINI treatments induced aberrant, higher order IN multimerization in virions and resulted in eccentric, non-infectious virus particles. These studies have suggested that the correctly ordered IN structure is important for virus particle morphogenesis and highlighted IN multimerization as a plausible therapeutic target for developing new inhibitors to enhance treatment options for HIV-1-infected patients.
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Affiliation(s)
- Lei Feng
- The Center for Retrovirus Research and College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA
| | - Ross C. Larue
- The Center for Retrovirus Research and College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA
| | - Alison Slaughter
- The Center for Retrovirus Research and College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA
| | - Jacques J. Kessl
- The Center for Retrovirus Research and College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA
| | - Mamuka Kvaratskhelia
- The Center for Retrovirus Research and College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA
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44
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Host factors for retroviral integration site selection. Trends Biochem Sci 2014; 40:108-16. [PMID: 25555456 DOI: 10.1016/j.tibs.2014.12.001] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 11/15/2014] [Accepted: 12/02/2014] [Indexed: 11/22/2022]
Abstract
To achieve productive infection, retroviruses such as HIV stably integrate their reverse transcribed RNA genome into a host chromosome. Each retroviral family preferentially integrates near a unique subset of genomic features. HIV integrase (IN) is targeted to the body of active transcription units through interaction with lens epithelium-derived growth factor (LEDGF/p75). We describe the successful effort to develop inhibitors of the interaction between IN and LEDGF/p75, referred to as LEDGINs. Gammaretroviruses display a distinct integration pattern. Recently, BET (bromo- and extraterminal domain) proteins were identified as the LEDGF/p75 counterparts that target the integration of gammaretroviruses. The identification of the chromatin-readers LEDGF/p75 and BET as cellular cofactors that orchestrate lentiviral or gammaretroviral integration opens new avenues to developing safer viral vectors for gene therapy.
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45
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Alpharetroviral vectors: from a cancer-causing agent to a useful tool for human gene therapy. Viruses 2014; 6:4811-38. [PMID: 25490763 PMCID: PMC4276931 DOI: 10.3390/v6124811] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 11/07/2014] [Accepted: 11/20/2014] [Indexed: 12/24/2022] Open
Abstract
Gene therapy using integrating retroviral vectors has proven its effectiveness in several clinical trials for the treatment of inherited diseases and cancer. However, vector-mediated adverse events related to insertional mutagenesis were also observed, emphasizing the need for safer therapeutic vectors. Paradoxically, alpharetroviruses, originally discovered as cancer-causing agents, have a more random and potentially safer integration pattern compared to gammaretro- and lentiviruses. In this review, we provide a short overview of the history of alpharetroviruses and explain how they can be converted into state-of-the-art gene delivery tools with improved safety features. We discuss development of alpharetroviral vectors in compliance with regulatory requirements for clinical translation, and provide an outlook on possible future gene therapy applications. Taken together, this review is a broad overview of alpharetroviral vectors spanning the bridge from their parental virus discovery to their potential applicability in clinical settings.
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46
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Craigie R, Bushman FD. Host Factors in Retroviral Integration and the Selection of Integration Target Sites. Microbiol Spectr 2014; 2:10.1128/microbiolspec.MDNA3-0026-2014. [PMID: 26104434 PMCID: PMC4525071 DOI: 10.1128/microbiolspec.mdna3-0026-2014] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Indexed: 02/07/2023] Open
Abstract
In order to replicate, a retrovirus must integrate a DNA copy of the viral RNA genome into a chromosome of the host cell. The study of retroviral integration has advanced considerably in the past few years. Here we focus on host factor interactions and the linked area of integration targeting. Genome-wide screens for cellular factors affecting HIV replication have identified a series of host cell proteins that may mediate subcellular trafficking for preintegration complexes, nuclear import, and integration target site selection. The cell transcriptional co-activator protein LEDGF/p75 has been identified as a tethering factor important for HIV integration, and recently, BET proteins (Brd2, 4, and 4) have been identified as tethering factors for the gammaretroviruses. A new class of HIV inhibitors has been developed targeting the HIV-1 IN-LEDGF binding site, though surprisingly these inhibitors appear to block assembly late during replication and do not act at the integration step. Going forward, genome-wide studies of HIV-host interactions offer many new starting points to investigate HIV replication and identify potential new inhibitor targets.
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Affiliation(s)
- Robert Craigie
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0560
| | - Frederic D. Bushman
- Department of Microbiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
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47
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Gu WG, Liu BN, Yuan JF. Virtual-screening targeting Human Immunodeficiency Virus type 1 integrase-lens epithelium-derived growth factor/p75 interaction for drug development. J Drug Target 2014; 23:134-9. [DOI: 10.3109/1061186x.2014.959020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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48
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Kvaratskhelia M, Sharma A, Larue RC, Serrao E, Engelman A. Molecular mechanisms of retroviral integration site selection. Nucleic Acids Res 2014; 42:10209-25. [PMID: 25147212 PMCID: PMC4176367 DOI: 10.1093/nar/gku769] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Retroviral replication proceeds through an obligate integrated DNA provirus, making retroviral vectors attractive vehicles for human gene-therapy. Though most of the host cell genome is available for integration, the process of integration site selection is not random. Retroviruses differ in their choice of chromatin-associated features and also prefer particular nucleotide sequences at the point of insertion. Lentiviruses including HIV-1 preferentially integrate within the bodies of active genes, whereas the prototypical gammaretrovirus Moloney murine leukemia virus (MoMLV) favors strong enhancers and active gene promoter regions. Integration is catalyzed by the viral integrase protein, and recent research has demonstrated that HIV-1 and MoMLV targeting preferences are in large part guided by integrase-interacting host factors (LEDGF/p75 for HIV-1 and BET proteins for MoMLV) that tether viral intasomes to chromatin. In each case, the selectivity of epigenetic marks on histones recognized by the protein tether helps to determine the integration distribution. In contrast, nucleotide preferences at integration sites seem to be governed by the ability for the integrase protein to locally bend the DNA duplex for pairwise insertion of the viral DNA ends. We discuss approaches to alter integration site selection that could potentially improve the safety of retroviral vectors in the clinic.
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Affiliation(s)
- Mamuka Kvaratskhelia
- Center for Retrovirus Research and College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA
| | - Amit Sharma
- Center for Retrovirus Research and College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA
| | - Ross C Larue
- Center for Retrovirus Research and College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA
| | - Erik Serrao
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute and Department of Medicine, Harvard Medical School, Boston, MA 02215, USA
| | - Alan Engelman
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute and Department of Medicine, Harvard Medical School, Boston, MA 02215, USA
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49
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Tan BH, Suzuki Y, Takahashi H, Ying PHR, Takahashi C, Han Q, Chin WX, Chao SH, Sawasaki T, Yamamoto N, Suzuki Y. Identification of RFPL3 protein as a novel E3 ubiquitin ligase modulating the integration activity of human immunodeficiency virus, type 1 preintegration complex using a microtiter plate-based assay. J Biol Chem 2014; 289:26368-26382. [PMID: 25107902 DOI: 10.1074/jbc.m114.561662] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Integration, one of the hallmarks of retrovirus replication, is mediated by a nucleoprotein complex called the preintegration complex (PIC), in which viral DNA is associated with many protein components that are required for completion of the early phase of infection. A striking feature of the PIC is its powerful integration activity in vitro. The PICs from a freshly isolated cytoplasmic extract of infected cells are able to insert viral DNA into exogenously added target DNA in vitro. Therefore, a PIC-based in vitro assay is a reliable system for assessing protein factors influencing retroviral integration. In this study, we applied a microtiter plate-based in vitro assay to a screening study using a protein library that was produced by the wheat germ cell-free protein synthesis system. Using a library of human E3 ubiquitin ligases, we identified RFPL3 as a potential stimulator of human immunodeficiency virus, type 1 (HIV-1) PIC integration activity in vitro. This enhancement of PIC activity by RFPL3 was likely to be attributed to its N-terminal RING domain. To further understand the functional role of RFPL3 in HIV infection, we created a human cell line overexpressing RFPL3. Immunoprecipitation analysis revealed that RFPL3 was associated with the human immunodeficiency virus, type 1 PICs in infected cells. More importantly, single-round HIV-1 infection was enhanced significantly by RFPL3 expression. Our proteomic approach displays an advantage in the identification of new cellular proteins affecting the integration activity of the PIC and, therefore, contributes to the understanding of functional interaction between retroviral integration complexes and host factors.
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Affiliation(s)
- Beng Hui Tan
- Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, 14 Medical Drive, #15-02, Singapore 117599, Singapore
| | - Yasutsugu Suzuki
- Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, 14 Medical Drive, #15-02, Singapore 117599, Singapore
| | - Hirotaka Takahashi
- Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, 14 Medical Drive, #15-02, Singapore 117599, Singapore
| | - Pamela Ho Rui Ying
- Veterinary Bioscience, Life Sciences and Chemical Technology, Ngee Ann Polytechnic, 535 Clementi Road, Singapore 599489, Singapore
| | - Chikako Takahashi
- Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, 14 Medical Drive, #15-02, Singapore 117599, Singapore
| | - Qi'En Han
- Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, 14 Medical Drive, #15-02, Singapore 117599, Singapore
| | - Wei Xin Chin
- Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, 14 Medical Drive, #15-02, Singapore 117599, Singapore
| | - Sheng-Hao Chao
- Expression Engineering Group, Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), 20 Biopolis Way, #06-01 Centros, Singapore 138668, Singapore
| | - Tatsuya Sawasaki
- Proteo-Science Center, Ehime University, 3 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan, and
| | - Naoki Yamamoto
- Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, 14 Medical Drive, #15-02, Singapore 117599, Singapore,.
| | - Youichi Suzuki
- Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, 14 Medical Drive, #15-02, Singapore 117599, Singapore,; Program in Emerging Infectious Diseases, Duke-NUS Graduate Medical School, 8 College Road, Singapore 169857, Singapore.
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50
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Gupta K, Brady T, Dyer BM, Malani N, Hwang Y, Male F, Nolte RT, Wang L, Velthuisen E, Jeffrey J, Van Duyne GD, Bushman FD. Allosteric inhibition of human immunodeficiency virus integrase: late block during viral replication and abnormal multimerization involving specific protein domains. J Biol Chem 2014; 289:20477-88. [PMID: 24904063 PMCID: PMC4110260 DOI: 10.1074/jbc.m114.551119] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 06/03/2014] [Indexed: 11/06/2022] Open
Abstract
HIV-1 replication in the presence of antiviral agents results in evolution of drug-resistant variants, motivating the search for additional drug classes. Here we report studies of GSK1264, which was identified as a compound that disrupts the interaction between HIV-1 integrase (IN) and the cellular factor lens epithelium-derived growth factor (LEDGF)/p75. GSK1264 displayed potent antiviral activity and was found to bind at the site occupied by LEDGF/p75 on IN by x-ray crystallography. Assays of HIV replication in the presence of GSK1264 showed only modest inhibition of the early infection steps and little effect on integration targeting, which is guided by the LEDGF/p75-IN interaction. In contrast, inhibition of late replication steps was more potent. Particle production was normal, but particles showed reduced infectivity. GSK1264 promoted aggregation of IN and preformed LEDGF/p75-IN complexes, suggesting a mechanism of inhibition. LEDGF/p75 was not displaced from IN during aggregation, indicating trapping of LEDGF/p75 in aggregates. Aggregation assays with truncated IN variants revealed that a construct with catalytic and C-terminal domains of IN only formed an open polymer associated with efficient drug-induced aggregation. These data suggest that the allosteric inhibitors of IN are promising antiviral agents and provide new information on their mechanism of action.
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Affiliation(s)
- Kushol Gupta
- the Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6059, and
| | - Troy Brady
- From the Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6076
| | - Benjamin M. Dyer
- From the Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6076
| | - Nirav Malani
- From the Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6076
| | - Young Hwang
- From the Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6076
| | - Frances Male
- From the Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6076
| | | | | | - Emile Velthuisen
- the HIV Discovery Performance Unit, Infectious Disease Therapy Area Unit, GlaxoSmithKline, Research Triangle Park, North Carolina 27709
| | - Jerry Jeffrey
- the HIV Discovery Performance Unit, Infectious Disease Therapy Area Unit, GlaxoSmithKline, Research Triangle Park, North Carolina 27709
| | - Gregory D. Van Duyne
- the Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6059, and
| | - Frederic D. Bushman
- From the Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6076
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