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Suleman S, Payne A, Bowden J, Haque SA, Zahn M, Fawaz S, Khalifa MS, Jobling S, Hay D, Franco M, Fronza R, Wang W, Strobel-Freidekind O, Deichmann A, Takeuchi Y, Waddington SN, Gil-Farina I, Schmidt M, Themis M. HIV- 1 lentivirus tethering to the genome is associated with transcription factor binding sites found in genes that favour virus survival. Gene Ther 2022; 29:720-729. [PMID: 35513551 PMCID: PMC9750860 DOI: 10.1038/s41434-022-00335-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 04/01/2022] [Accepted: 04/06/2022] [Indexed: 01/09/2023]
Abstract
Lentiviral vectors (LV) are attractive for permanent and effective gene therapy. However, integration into the host genome can cause insertional mutagenesis highlighting the importance of understanding of LV integration. Insertion site (IS) tethering is believed to involve cellular proteins such as PSIP1/LEDGF/p75, which binds to the virus pre-integration complexes (PICs) helping to target the virus genome. Transcription factors (TF) that bind both the vector LTR and host genome are also suspected influential to this. To determine the role of TF in the tethering process, we mapped predicted transcription factor binding sites (pTFBS) near to IS chosen by HIV-1 LV using a narrow 20 bp window in infected human induced pluripotent stem cells (iPSCs) and their hepatocyte-like cell (HLC) derivatives. We then aligned the pTFBS with these sequences found in the LTRs of native and self-inactivated LTRs. We found significant enrichment of these sequences for pTFBS essential to HIV-1 life cycle and virus survival. These same sites also appear in HIV-1 patient IS and in mice infected with HIV-1 based LV. This in silco data analysis suggests pTFBS present in the virus LTR and IS sites selected by HIV-1 LV are important to virus survival and propagation.
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Affiliation(s)
- Saqlain Suleman
- Department of Life Sciences, College of Health, Medicine & Life Sciences, Brunel University London, Uxbridge, UK
- Testavec Ltd, Queensgate House, Maidenhead, UK
| | - Annette Payne
- Testavec Ltd, Queensgate House, Maidenhead, UK
- Department of Computer Science, College of Engineering Design and Physical Sciences, Brunel University London, Uxbridge, UK
| | - Johnathan Bowden
- Department of Life Sciences, College of Health, Medicine & Life Sciences, Brunel University London, Uxbridge, UK
| | - Sharmin Al Haque
- Department of Life Sciences, College of Health, Medicine & Life Sciences, Brunel University London, Uxbridge, UK
| | - Marco Zahn
- Genewerk GmbH, Heidelberg, Germany
- University Heidelberg, Medical Faculty, Heidelberg, Germany
| | - Serena Fawaz
- Department of Life Sciences, College of Health, Medicine & Life Sciences, Brunel University London, Uxbridge, UK
| | - Mohammad S Khalifa
- Department of Life Sciences, College of Health, Medicine & Life Sciences, Brunel University London, Uxbridge, UK
| | - Susan Jobling
- Testavec Ltd, Queensgate House, Maidenhead, UK
- Institute of Environment, Health and Societies, College of Business, Arts and Social Sciences, Brunel University London, Uxbridge, UK
| | - David Hay
- Centre for Regenerative Medicine, The University of Edinburgh, Edinburgh, UK
| | | | | | - Wei Wang
- Genewerk GmbH, Heidelberg, Germany
| | | | | | - Yasuhiro Takeuchi
- Division of Infection and Immunity, University College London, London, UK
- Division of Advanced Therapies, National Institute for Biological Standards and Control, Potters Bar, UK
| | - Simon N Waddington
- Gene Transfer Technology, EGA Institute for Women's Health, University College London, London, UK
- MRC Antiviral Gene Therapy Research Unit, Faculty of Health Sciences, University of the Witswatersrand, Johannesburg, South Africa
| | | | - Manfred Schmidt
- Genewerk GmbH, Heidelberg, Germany
- Department of Translational Oncology, NCT and DKFZ, Heidelberg, Germany
| | - Michael Themis
- Department of Life Sciences, College of Health, Medicine & Life Sciences, Brunel University London, Uxbridge, UK.
- Division of Ecology and Evolution, Department of Life Sciences, Imperial College London, London, UK.
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2
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Richetta C, Tu NQ, Delelis O. Different Pathways Conferring Integrase Strand-Transfer Inhibitors Resistance. Viruses 2022; 14:v14122591. [PMID: 36560595 PMCID: PMC9785060 DOI: 10.3390/v14122591] [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: 10/25/2022] [Revised: 11/17/2022] [Accepted: 11/19/2022] [Indexed: 11/23/2022] Open
Abstract
Integrase Strand Transfer Inhibitors (INSTIs) are currently used as the most effective therapy in the treatment of human immunodeficiency virus (HIV) infections. Raltegravir (RAL) and Elvitegravir (EVG), the first generation of INSTIs used successfully in clinical treatment, are susceptible to the emergence of viral resistance and have a high rate of cross-resistance. To counteract these resistant mutants, second-generation INSTI drugs have been developed: Dolutegravir (DTG), Cabotegravir (CAB), and Bictegravir (BIC). However, HIV is also able to develop resistance mechanisms against the second-generation of INSTIs. This review describes the mode of action of INSTIs and then summarizes and evaluates some typical resistance mutations, such as substitution and insertion mutations. The role of unintegrated viral DNA is also discussed as a new pathway involved in conferring resistance to INSTIs. This allows us to have a more detailed understanding of HIV resistance to these inhibitors, which may contribute to the development of new INSTIs in the future.
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3
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Current Research on HIV Drug Resistance—A Topical Collection with “Pathogens”. Pathogens 2022; 11:pathogens11090966. [PMID: 36145398 PMCID: PMC9504728 DOI: 10.3390/pathogens11090966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 08/22/2022] [Indexed: 11/17/2022] Open
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4
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Smith RA, Wu VH, Song J, Raugi DN, Diallo Mbaye K, Seydi M, Gottlieb GS. Spectrum of Activity of Raltegravir and Dolutegravir Against Novel Treatment-Associated Mutations in HIV-2 Integrase: A Phenotypic Analysis Using an Expanded Panel of Site-Directed Mutants. J Infect Dis 2022; 226:497-509. [PMID: 35134180 PMCID: PMC9417127 DOI: 10.1093/infdis/jiac037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 01/28/2022] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Integrase inhibitors (INIs) are a key component of antiretroviral therapy for human immunodeficiency virus-1 (HIV-1) and HIV-2 infection. Although INI resistance pathways are well-defined for HIV-1, mutations that emerge in HIV-2 in response to INIs are incompletely characterized. METHODS We performed systematic searches of GenBank and HIV-2 drug resistance literature to identify treatment-associated mutations for phenotypic evaluation. We then constructed a library of 95 mutants of HIV-2ROD9 that contained single or multiple amino acid changes in the integrase protein. Each variant was tested for susceptibility to raltegravir and dolutegravir using a single-cycle indicator cell assay. RESULTS We observed extensive cross-resistance between raltegravir and dolutegravir in HIV-2ROD9. HIV-2-specific integrase mutations Q91R, E92A, A153G, and H157Q/S, which have not been previously characterized, significantly increased the half maximum effective concentration (EC50) for raltegravir when introduced into 1 or more mutational backgrounds; mutations E92A/Q, T97A, and G140A/S conferred similar enhancements of dolutegravir resistance. HIV-2ROD9 variants encoding G118R alone, or insertions of residues SREGK or SREGR at position 231, were resistant to both INIs. CONCLUSIONS Our analysis demonstrates the contributions of novel INI-associated mutations to raltegravir and dolutegravir resistance in HIV-2. These findings should help to improve algorithms for genotypic drug resistance testing in HIV-2-infected individuals.
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Affiliation(s)
- Robert A Smith
- Correspondence: Robert A. Smith, PhD, Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, 750 Republican Street, Building E, Box 358061, Seattle, WA 98109 ()
| | - Vincent H Wu
- Center for Emerging and Reemerging Infectious Diseases, University of Washington, Seattle, Washington, USA,Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, Washington, USA
| | - Jennifer Song
- Center for Emerging and Reemerging Infectious Diseases, University of Washington, Seattle, Washington, USA,Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, Washington, USA
| | - Dana N Raugi
- Center for Emerging and Reemerging Infectious Diseases, University of Washington, Seattle, Washington, USA,Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, Washington, USA
| | - Khardiata Diallo Mbaye
- Service des Maladies Infectieuses et Tropicales, Centre Hospitalier National Universitaire de Fann, Dakar, Senegal
| | - Moussa Seydi
- Service des Maladies Infectieuses et Tropicales, Centre Hospitalier National Universitaire de Fann, Dakar, Senegal
| | - Geoffrey S Gottlieb
- Center for Emerging and Reemerging Infectious Diseases, University of Washington, Seattle, Washington, USA,Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, Washington, USA,Department of Global Health, University of Washington, Seattle, Washington, USA
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5
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Hikichi Y, Van Duyne R, Pham P, Groebner JL, Wiegand A, Mellors JW, Kearney MF, Freed EO. Mechanistic Analysis of the Broad Antiretroviral Resistance Conferred by HIV-1 Envelope Glycoprotein Mutations. mBio 2021; 12:e03134-20. [PMID: 33436439 PMCID: PMC7844542 DOI: 10.1128/mbio.03134-20] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 11/16/2020] [Indexed: 02/06/2023] Open
Abstract
Despite the effectiveness of antiretroviral (ARV) therapy, virological failure can occur in some HIV-1-infected patients in the absence of mutations in drug target genes. We previously reported that, in vitro, the lab-adapted HIV-1 NL4-3 strain can acquire resistance to the integrase inhibitor dolutegravir (DTG) by acquiring mutations in the envelope glycoprotein (Env) that enhance viral cell-cell transmission. In this study, we investigated whether Env-mediated drug resistance extends to ARVs other than DTG and whether it occurs in other HIV-1 isolates. We demonstrate that Env mutations can reduce susceptibility to multiple classes of ARVs and also increase resistance to ARVs when coupled with target-gene mutations. We observe that the NL4-3 Env mutants display a more stable and closed Env conformation and lower rates of gp120 shedding than the WT virus. We also selected for Env mutations in clinically relevant HIV-1 isolates in the presence of ARVs. These Env mutants exhibit reduced susceptibility to DTG, with effects on replication and Env structure that are HIV-1 strain dependent. Finally, to examine a possible in vivo relevance of Env-mediated drug resistance, we performed single-genome sequencing of plasma-derived virus from five patients failing an integrase inhibitor-containing regimen. This analysis revealed the presence of several mutations in the highly conserved gp120-gp41 interface despite low frequency of resistance mutations in integrase. These results suggest that mutations in Env that enhance the ability of HIV-1 to spread via a cell-cell route may increase the opportunity for the virus to acquire high-level drug resistance mutations in ARV target genes.IMPORTANCE Although combination antiretroviral (ARV) therapy is highly effective in controlling the progression of HIV disease, drug resistance can be a major obstacle. Recent findings suggest that resistance can develop without ARV target gene mutations. We previously reported that mutations in the HIV-1 envelope glycoprotein (Env) confer resistance to an integrase inhibitor. Here, we investigated the mechanism of Env-mediated drug resistance and the possible contribution of Env to virological failure in vivo We demonstrate that Env mutations can reduce sensitivity to major classes of ARVs in multiple viral isolates and define the effect of the Env mutations on Env subunit interactions. We observed that many Env mutations accumulated in individuals failing integrase inhibitor therapy despite a low frequency of resistance mutations in integrase. Our findings suggest that broad-based Env-mediated drug resistance may impact therapeutic strategies and provide clues toward understanding how ARV-treated individuals fail therapy without acquiring mutations in drug target genes.
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Affiliation(s)
- Yuta Hikichi
- Virus-Cell Interaction Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, USA
| | - Rachel Van Duyne
- Virus-Cell Interaction Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, USA
| | - Phuong Pham
- Virus-Cell Interaction Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, USA
| | - Jennifer L Groebner
- Translational Research Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, USA
| | - Ann Wiegand
- Translational Research Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, USA
| | - John W Mellors
- Department of Immunology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Mary F Kearney
- Translational Research Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, USA
| | - Eric O Freed
- Virus-Cell Interaction Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, USA
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6
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Trivedi J, Mahajan D, Jaffe RJ, Acharya A, Mitra D, Byrareddy SN. Recent Advances in the Development of Integrase Inhibitors for HIV Treatment. Curr HIV/AIDS Rep 2020; 17:63-75. [PMID: 31965427 PMCID: PMC7004278 DOI: 10.1007/s11904-019-00480-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
PURPOSE OF THE REVIEW The complex multistep life cycle of HIV allows it to proliferate within the host and integrate its genome in to the host chromosomal DNA. This provirus can remain dormant for an indefinite period. The process of integration, governed by integrase (IN), is highly conserved across the Retroviridae family. Hence, targeting integration is not only expected to block HIV replication but may also reveal new therapeutic strategies to treat HIV as well as other retrovirus infections. RECENT FINDINGS HIV integrase (IN) has gained attention as the most promising therapeutic target as there are no equivalent homologues of IN that has been discovered in humans. Although current nano-formulated long-acting IN inhibitors have demonstrated the phenomenal ability to block HIV integration and replication with extraordinary half-life, they also have certain limitations. In this review, we have summarized the current literature on clinically established IN inhibitors, their mechanism of action, the advantages and disadvantages associated with their therapeutic application, and finally current HIV cure strategies using these inhibitors.
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Affiliation(s)
- Jay Trivedi
- National Centre for Cell Science, Pune University Campus, Pune, Maharashtra, India
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, USA
| | - Dinesh Mahajan
- Drug Discovery Research Centre, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad, Haryana, India
| | - Russell J Jaffe
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, USA
| | - Arpan Acharya
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, USA
| | - Debashis Mitra
- National Centre for Cell Science, Pune University Campus, Pune, Maharashtra, India.
- Centre for DNA Fingerprinting and Diagnostics, Uppal Telangana state, Hyderabad, India.
| | - Siddappa N Byrareddy
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, USA.
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE, USA.
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA.
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7
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Collier DA, Monit C, Gupta RK. The Impact of HIV-1 Drug Escape on the Global Treatment Landscape. Cell Host Microbe 2019; 26:48-60. [PMID: 31295424 DOI: 10.1016/j.chom.2019.06.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The rising prevalence of HIV drug resistance (HIVDR) could threaten gains made in combating the HIV epidemic and compromise the 90-90-90 target proposed by United Nations Programme on HIV/AIDS (UNAIDS) to have achieved virological suppression in 90% of all persons receiving antiretroviral therapy (ART) by the year 2020. HIVDR has implications for the persistence of HIV, the selection of current and future ART drug regimens, and strategies of vaccine and cure development. Focusing on drug classes that are in clinical use, this Review critically summarizes what is known about the mechanisms the virus utilizes to escape drug control. Armed with this knowledge, strategies to limit the expansion of HIVDR are proposed.
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Affiliation(s)
- D A Collier
- Division of Infection and Immunity, University College London, London, UK
| | - C Monit
- Division of Infection and Immunity, University College London, London, UK
| | - R K Gupta
- Department of Medicine, University of Cambridge, Cambridge, UK.
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8
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Heterocycle amide isosteres: An approach to overcoming resistance for HIV-1 integrase strand transfer inhibitors. Bioorg Med Chem Lett 2019; 30:126784. [PMID: 31761656 DOI: 10.1016/j.bmcl.2019.126784] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 10/22/2019] [Accepted: 10/24/2019] [Indexed: 01/12/2023]
Abstract
A series of heterocyclic pyrimidinedione-based HIV-1 integrase inhibitors was prepared and screened for activity against purified integrase enzyme and/or viruses modified with the following mutations within integrase: Q148R, Q148H/G140S and N155H. These are mutations that result in resistance to the first generation integrase inhibitors raltegravir and elvitegravir. Based on consideration of drug-target interactions, an approach was undertaken to replace the amide moiety of the first generation pyrimidinedione inhibitor with azole heterocycles that could retain potency against these key resistance mutations. An imidazole moiety was found to be the optimal amide substitute and the observed activity was rationalized with the use of calculated properties and modeling. Rat pharmacokinetic (PK) studies of the lead imidazole compounds demonstrated moderate clearance and moderate exposure.
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9
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Wijting IEA, Lungu C, Rijnders BJA, van der Ende ME, Pham HT, Mesplede T, Pas SD, Voermans JJC, Schuurman R, van de Vijver DAMC, Boers PHM, Gruters RA, Boucher CAB, van Kampen JJA. HIV-1 Resistance Dynamics in Patients With Virologic Failure to Dolutegravir Maintenance Monotherapy. J Infect Dis 2019; 218:688-697. [PMID: 29617822 DOI: 10.1093/infdis/jiy176] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 03/18/2018] [Indexed: 11/14/2022] Open
Abstract
Background A high genetic barrier to resistance to the integrase strand transfer inhibitor (INSTI) dolutegravir has been reported in vitro and in vivo. We describe the dynamics of INSTI resistance-associated mutations (INSTI-RAMs) and mutations in the 3'-polypurine tract (3'-PPT) in relation to virologic failure (VF) observed in the randomized Dolutegravir as Maintenance Monotherapy for HIV-1 study (DOMONO, NCT02401828). Methods From 10 patients with VF, plasma samples were collected before the start of cART and during VF, and were used to generate Sanger sequences of integrase, the 5' terminal bases of the 3' long terminal repeat (LTR), and the 3'-PPT. Results Median human immunodeficiency virus RNA load at VF was 3490 copies/mL (interquartile range 1440-4990 copies/mL). INSTI-RAMs (S230R, R263K, N155H, and E92Q+N155H) were detected in 4 patients, no INSTI-RAMs were detected in 4 patients, and sequencing of the integrase gene was unsuccessful in 2 patients. The time to VF ranged from 4 weeks to 72 weeks. In 1 patient, mutations developed in the highly conserved 3'-PPT. No changes in the terminal bases of the 3'-LTR were observed. Conclusions The genetic barrier to resistance is too low to justify dolutegravir maintenance monotherapy because single INSTI-RAMs are sufficient to cause VF. The large variation in time to VF suggests that stochastic reactivation of a preexisting provirus containing a single INSTI-RAM is the mechanism for failure. Changes in the 3'-PPT point to a new dolutegravir resistance mechanism in vivo. Clinical Trials Registration NCT02401828.
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Affiliation(s)
- Ingeborg E A Wijting
- Department of Internal Medicine and Infectious Diseases, Erasmus MC, Rotterdam, the Netherlands
| | - Cynthia Lungu
- Department of Viroscience, Erasmus MC, Rotterdam, the Netherlands
| | - Bart J A Rijnders
- Department of Internal Medicine and Infectious Diseases, Erasmus MC, Rotterdam, the Netherlands
| | - Marchina E van der Ende
- Department of Internal Medicine and Infectious Diseases, Erasmus MC, Rotterdam, the Netherlands
| | - Hanh T Pham
- McGill University AIDS Centre, Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Canada.,Department of Microbiology and Immunology, Faculty of Medicine, McGill University, Montreal, Canada
| | - Thibault Mesplede
- McGill University AIDS Centre, Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Canada.,Department of Microbiology and Immunology, Faculty of Medicine, McGill University, Montreal, Canada
| | - Suzan D Pas
- Department of Viroscience, Erasmus MC, Rotterdam, the Netherlands
| | | | - Rob Schuurman
- Division of Virology, Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, the Netherlands
| | | | | | - Rob A Gruters
- Department of Viroscience, Erasmus MC, Rotterdam, the Netherlands
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10
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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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11
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Barski MS, Minnell JJ, Maertens GN. Inhibition of HTLV-1 Infection by HIV-1 First- and Second-Generation Integrase Strand Transfer Inhibitors. Front Microbiol 2019; 10:1877. [PMID: 31474960 PMCID: PMC6705210 DOI: 10.3389/fmicb.2019.01877] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 07/30/2019] [Indexed: 12/21/2022] Open
Abstract
More than 10 million people worldwide are infected with the retrovirus human T-cell lymphotropic virus type 1 (HTLV-1). Infection phenotypes can range from asymptomatic to severe adult T-cell leukemia/lymphoma (ATLL) and HTLV-1-associated myelopathy. HTLV-1, like human immunodeficiency virus type 1 (HIV-1), is a blood-borne pathogen and viral infection happens in a similar fashion, with the major mode of transmission through breastfeeding. There is a strong correlation between time of infection and disease development, with a higher incidence of ATLL in patients infected during childhood. There is no successful therapeutic or preventative regimen for HTLV-1. It is therefore essential to develop therapies to inhibit transmission or block the onset/development of HTLV-1 associated diseases. Recently, we have seen the overwhelming success of integrase strand transfer inhibitors (INSTIs) in the treatment of HIV-1. Previously, raltegravir was shown to inhibit HTLV-1 infection. Here, we tested FDA-approved and two Phase II HIV-1 INSTIs in vitro and in a cell-to-cell infection model and show that they are highly active in blocking HTLV-1 infection, with bictegravir (EC50 = 0.30 ± 0.17 nM) performing best overall. INSTIs, in particular bictegravir, are more potent in blocking HTLV-1 transmission than tenofovir disproxil fumarate (TDF), an RT inhibitor. Our data suggest that HIV-1 INSTIs could present a good clinical strategy in HTLV-1 management and justifies the inclusion of INSTIs in clinical trials.
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Affiliation(s)
- Michał S Barski
- Division of Infectious Diseases, Section of Molecular Virology, Department of Medicine, St Mary's Hospital, Imperial College London, London, United Kingdom
| | - Jordan J Minnell
- Division of Infectious Diseases, Section of Molecular Virology, Department of Medicine, St Mary's Hospital, Imperial College London, London, United Kingdom
| | - Goedele N Maertens
- Division of Infectious Diseases, Section of Molecular Virology, Department of Medicine, St Mary's Hospital, Imperial College London, London, United Kingdom
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12
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Ammar FF, Hobaika Z, Abdel-Azeim S, Zargarian L, Maroun RG, Fermandjian S. A targeted DNA substrate mechanism for the inhibition of HIV-1 integrase by inhibitors with antiretroviral activity. FEBS Open Bio 2016; 6:234-50. [PMID: 27239438 PMCID: PMC4821353 DOI: 10.1002/2211-5463.12025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 11/25/2015] [Accepted: 12/16/2015] [Indexed: 12/21/2022] Open
Abstract
We recently reported that viral DNA could be the primary target of raltegravir (RAL), an efficient anti‐HIV‐1 drug, which acts by inhibiting integrase. To elucidate this mechanism, we conducted a comparative analysis of RAL and TB11, a diketoacid abandoned as an anti‐HIV‐1 drug for its weak efficiency and marked toxicity, and tested the effects of the catalytic cofactor Mg2+ (5 mm) on drug‐binding properties. We used circular dichroism and fluorescence to determine drug affinities for viral DNA long terminal repeats (LTRs) and peptides derived from the integrase active site and DNA retardation assays to assess drug intercalation into DNA base pairs. We found that RAL bound more tightly to LTR ends than did TB11 (a diketo acid bearing an azido group) and that Mg2+ significantly increased the affinity of both RAL and TB11. We also observed a good relationship between drug binding with processed LTR and strand transfer inhibition. This unusual type of inhibition was caused by Mg2+‐assisted binding of drugs to DNA substrate, rather than to enzyme. Notably, while RAL bound exclusively to the cleavable/cleaved site, TB11 further intercalated into DNA base pairs and interacted with the integrase‐derived peptides. These unwanted binding sites explain the weaker bioavailability and higher toxicity of TB11 compared with the more effective RAL.
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Affiliation(s)
- Farah F Ammar
- Centre d'Analyses et de Recherche UR EGFEM Faculté des Sciences Université Saint-Joseph Beirut Lebanon; LBPA, UMR8113 du CNRS Ecole Normale Supérieure de Cachan Cedex Cachan France
| | - Zeina Hobaika
- Centre d'Analyses et de Recherche UR EGFEM Faculté des Sciences Université Saint-Joseph Beirut Lebanon
| | - Safwat Abdel-Azeim
- LBPA, UMR8113 du CNRS Ecole Normale Supérieure de Cachan Cedex Cachan France
| | - Loussinée Zargarian
- LBPA, UMR8113 du CNRS Ecole Normale Supérieure de Cachan Cedex Cachan France
| | - Richard G Maroun
- Centre d'Analyses et de Recherche UR EGFEM Faculté des Sciences Université Saint-Joseph Beirut Lebanon
| | - Serge Fermandjian
- LBPA, UMR8113 du CNRS Ecole Normale Supérieure de Cachan Cedex Cachan France; Chemistry and Biology, Nucleo(s)tides and Immunology for Therapy UMR8601 CNRS Paris Cedex 06 France
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Dayer MR. Comparison of Newly Assembled Full Length HIV-1 Integrase With Prototype Foamy Virus Integrase: Structure-Function Prospective. Jundishapur J Microbiol 2016; 9:e29773. [PMID: 27540450 PMCID: PMC4976072 DOI: 10.5812/jjm.29773] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2015] [Revised: 11/17/2015] [Accepted: 11/30/2015] [Indexed: 01/24/2023] Open
Abstract
Background Drug design against human immunodeficiency virus type 1 (HIV-1) integrase through its mechanistic study is of great interest in the area in biological research. The main obstacle in this area is the absence of the full-length crystal structure for HIV-1 integrase to be used as a model. A complete structure, similar to HIV-1 of a prototype foamy virus integrase in complex with DNA, including all conservative residues, is available and has been extensively used in recent investigations. Objectives The aim of this study was to determine whether the above model is precisely representative of HIV-1 integrase. This would critically determine the success of any designed drug using the model in deactivation of integrase and AIDS treatment. Materials and Methods Primarily, a new structure for HIV-1 was constructed, using a crystal structure of prototype foamy virus as the starting structure. The constructed structure of HIV-1 integrase was simultaneously simulated with a prototype foamy virus integrase on a separate occasion. Results Our results indicate that the HIV-1 system behaves differently from the prototype foamy virus in terms of folding, hydration, hydrophobicity of binding site and stability. Conclusions Based on our findings, we can conclude that HIV-1 integrase is vastly different from the prototype foamy virus integrase and does not resemble it, and the modeling output of the prototype foamy virus simulations could not be simply generalized to HIV-1 integrase. Therefore, our HIV-1 model seems to be more representative and more useful for future research.
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Affiliation(s)
- Mohammad Reza Dayer
- Department of Biology, Faculty of Science, Shahid Chamran University, Ahvaz, IR Iran
- Corresponding author: Mohammad Reza Dayer, Department of Biology, Faculty of Sciences, Shahid Chamran University, Ahvaz, IR Iran. Tel: +98-6113331045, Fax: +98-6113331045, E-mail:
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Rausch JW, Tian M, Li Y, Angelova L, Bagaya BS, Krebs KC, Qian F, Zhu C, Arts EJ, Le Grice SFJ, Gao Y. SiRNA-induced mutation in HIV-1 polypurine tract region and its influence on viral fitness. PLoS One 2015; 10:e0122953. [PMID: 25860884 PMCID: PMC4393142 DOI: 10.1371/journal.pone.0122953] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 02/16/2015] [Indexed: 02/06/2023] Open
Abstract
Converting single-stranded viral RNA into double stranded DNA for integration is an essential step in HIV-1 replication. Initial polymerization of minus-strand DNA is primed from a host derived tRNA, whereas subsequent plus-strand synthesis requires viral primers derived from the 3' and central polypurine tracts (3' and cPPTs). The 5' and 3' termini of these conserved RNA sequence elements are precisely cleaved by RT-associated RNase H to generate specific primers that are used to initiate plus-strand DNA synthesis. In this study, siRNA wad used to produce a replicative HIV-1 variant contained G(-1)A and T(-16)A substitutions within/adjacent to the 3'PPT sequence. Introducing either or both mutations into the 3'PPT region or only the G(-1)A substitution in the cPPT region of NL4-3 produced infectious virus with decreased fitness relative to the wild-type virus. In contrast, introducing the T(-16)A or both mutations into the cPPT rendered the virus(es) incapable of replication, most likely due to the F185L integrase mutation produced by this nucleotide substitution. Finally, the effects of G(-1)A and T(-16)A mutations on cleavage of the 3'PPT were examined using an in vitro RNase H cleavage assay. Substrate containing both mutations was mis-cleaved to a greater extent than either wild-type substrate or substrate containing the T(-16)A mutation alone, which is consistent with the observed effects of the equivalent nucleotide substitutions on the replication fitness of NL4-3 virus. In conclusion, siRNA targeting of the HIV-1 3'PPT region can substantially suppress virus replication, and this selective pressure can be used to generate infectious virus containing mutations within or near the HIV-1 PPT. Moreover, in-depth analysis of the resistance mutations demonstrates that although virus containing a G(-1)A mutation within the 3'PPT is capable of replication, this nucleotide substitution shifts the 3'-terminal cleavage site in the 3'PPT by one nucleotide (nt) and significantly reduces viral fitness.
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Affiliation(s)
- Jason W. Rausch
- HIV Drug Resistance Program, Frederick National Laboratory for Cancer Research, Frederick, Maryland, United States of America
| | - Meijuan Tian
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Yuejin Li
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Lora Angelova
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Bernard S. Bagaya
- Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Kendall C. Krebs
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Feng Qian
- Suzhou Fifth People’s Hospital, Suzhou, Jiangsu, China
| | - Chuanwu Zhu
- Suzhou Fifth People’s Hospital, Suzhou, Jiangsu, China
| | - Eric J. Arts
- Department of Microbiology and Immunology, Western University, London, Ontario, Canada
| | - Stuart F. J. Le Grice
- HIV Drug Resistance Program, Frederick National Laboratory for Cancer Research, Frederick, Maryland, United States of America
| | - Yong Gao
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, Cleveland, Ohio, United States of America
- Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, Ohio, United States of America
- * E-mail:
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Integrase as a Novel Target for the Inhibition of Human Immunodeficiency Virus Type 1 Infection: Current Status and Future Perspectives. Antiviral Res 2014. [DOI: 10.1128/9781555815493.ch5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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16
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Preclinical characterization of BMS-791325, an allosteric inhibitor of hepatitis C Virus NS5B polymerase. Antimicrob Agents Chemother 2014; 58:3485-95. [PMID: 24733465 DOI: 10.1128/aac.02495-13] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
BMS-791325 is an allosteric inhibitor that binds to thumb site 1 of the hepatitis C virus (HCV) NS5B RNA-dependent RNA polymerase. BMS-791325 inhibits recombinant NS5B proteins from HCV genotypes 1, 3, 4, and 5 at 50% inhibitory concentrations (IC50) below 28 nM. In cell culture, BMS-791325 inhibited replication of HCV subgenomic replicons representing genotypes 1a and 1b at 50% effective concentrations (EC50s) of 3 nM and 6 nM, respectively, with similar (3 to 18 nM) values for genotypes 3a, 4a, and 5a. Potency against genotype 6a showed more variability (9 to 125 nM), and activity was weaker against genotype 2 (EC50, 87 to 925 nM). Specificity was demonstrated by the absence of activity (EC50s of >4 μM) against a panel of mammalian viruses, and cytotoxic concentrations (50%) were >3,000-fold above the HCV EC50. Resistance substitutions selected by BMS-791325 in genotype 1 replicons mostly mapped to a single site, NS5B amino acid 495 (P495A/S/L/T). Additive or synergistic activity was observed in combination studies using BMS-791325 with alfa interferon plus ribavirin, inhibitors of NS3 protease or NS5A, and other classes of NS5B inhibitor (palm site 2-binding or nucleoside analogs). Plasma and liver exposures in vivo in several animal species indicated that BMS-791325 has a hepatotropic disposition (liver-to-plasma ratios ranging from 1.6- to 60-fold across species). Twenty-four hours postdose, liver exposures across all species tested were ≥ 10-fold above the inhibitor EC50s observed with HCV genotype 1 replicons. These findings support the evaluation of BMS-791325 in combination regimens for the treatment of HCV. Phase 3 studies are ongoing.
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Arora R, de Beauchene IC, Polanski J, Laine E, Tchertanov L. Raltegravir flexibility and its impact on recognition by the HIV-1 IN targets. J Mol Recognit 2013; 26:383-401. [PMID: 23836466 DOI: 10.1002/jmr.2277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Revised: 04/04/2013] [Accepted: 04/07/2013] [Indexed: 01/10/2023]
Abstract
HIV-1 IN is a pertinent target for the development of AIDS chemotherapy. The first IN-specific inhibitor approved for the treatment of HIV/AIDS, RAL, was designed to block the ST reaction. We characterized the structural and conformational features of RAL and its recognition by putative HIV-1 targets - the unbound IN, the vDNA, and the IN•vDNA complex - mimicking the IN states over the integration process. RAL binding to the targets was studied by performing an extensive sampling of the inhibitor conformational landscape and by using four different docking algorithms: Glide, Autodock, VINA, and SurFlex. The obtained data evidenced that: (i) a large binding pocket delineated by the active site and an extended loop in the unbound IN accommodates RAL in distinct conformational states all lacking specific interactions with the target; (ii) a well-defined cavity formed by the active site, the vDNA, and the shortened loop in the IN•vDNA complex provide a more optimized inhibitor binding site in which RAL chelates Mg(2+) cations; (iii) a specific recognition between RAL and the unpaired cytosine of the processed DNA is governed by a pair of strong H-bonds similar to those observed in DNA base pair G-C. The identified RAL pose at the cleaved vDNA shed light on a putative step of RAL inhibition mechanism. This modeling study indicates that the inhibition process may include as a first step RAL recognition by the processed vDNA bound to a transient intermediate IN state, and thus provides a potentially promising route to the design of IN inhibitors with improved affinity and selectivity.
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Affiliation(s)
- Rohit Arora
- Bioinformatics, Molecular Dynamics & Modeling (BiMoDyM), Laboratoire de Biologie et Pharmacologie Appliquée (LBPA-CNRS), Ecole Normale Supérieure de Cachan, 61 avenue du Président Wilson, 94235, Cachan, France
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Impact of primary elvitegravir resistance-associated mutations in HIV-1 integrase on drug susceptibility and viral replication fitness. Antimicrob Agents Chemother 2013; 57:2654-63. [PMID: 23529738 DOI: 10.1128/aac.02568-12] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Elvitegravir (EVG) is an effective HIV-1 integrase (IN) strand transfer inhibitor (INSTI) in advanced clinical development. Primary INSTI resistance-associated mutations (RAMs) at six IN positions have been identified in HIV-1-infected patients failing EVG-containing regimens in clinical studies: T66I/A/K, E92Q/G, T97A, S147G, Q148R/H/K, and N155H. In this study, the effect of these primary IN mutations, alone and in combination, on susceptibility to the INSTIs EVG, raltegravir (RAL), and dolutegravir (DTG); IN enzyme activities; and viral replication fitness was characterized. Recombinant viruses containing the six most common mutations exhibited a range of reduced EVG susceptibility: 92-fold for Q148R, 30-fold for N155H, 26-fold for E92Q, 10-fold for T66I, 4-fold for S147G, and 2-fold for T97A. Less commonly observed primary IN mutations also showed a range of reduced EVG susceptibilities: 40- to 94-fold for T66K and Q148K and 5- to 10-fold for T66A, E92G, and Q148H. Some primary IN mutations exhibited broad cross-resistance between EVG and RAL (T66K, E92Q, Q148R/H/K, and N155H), while others retained susceptibility to RAL (T66I/A, E92G, T97A, and S147G). Dual combinations of primary IN mutations further reduced INSTI susceptibility, replication capacity, and viral fitness relative to either mutation alone. Susceptibility to DTG was retained by single primary IN mutations but reduced by dual mutation combinations with Q148R. Primary EVG RAMs also diminished IN enzymatic activities, concordant with their structural proximity to the active site. Greater reductions in viral fitness of dual mutation combinations may explain why some primary INSTI RAMs do not readily coexist on the same HIV-1 genome but rather establish independent pathways of resistance to EVG.
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Abstract
Integrase (IN) is a clinically validated target for the treatment of human immunodeficiency virus infections and raltegravir exhibits remarkable clinical activity. The next most advanced IN inhibitor is elvitegravir. However, mutant viruses lead to treatment failure and mutations within the IN coding sequence appear to confer cross-resistance. The characterization of those mutations is critical for the development of second generation IN inhibitors to overcome resistance. This review focuses on IN resistance based on structural and biochemical data, and on the role of the IN flexible loop i.e., between residues G140-G149 in drug action and resistance.
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Affiliation(s)
| | | | | | - Yves Pommier
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-301-496-5944; Fax: +1-301-402-0752
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Ammar FF, Abdel-Azeim S, Zargarian L, Hobaika Z, Maroun RG, Fermandjian S. Unprocessed viral DNA could be the primary target of the HIV-1 integrase inhibitor raltegravir. PLoS One 2012; 7:e40223. [PMID: 22768342 PMCID: PMC3388078 DOI: 10.1371/journal.pone.0040223] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Accepted: 06/02/2012] [Indexed: 12/18/2022] Open
Abstract
Integration of HIV DNA into host chromosome requires a 3'-processing (3'-P) and a strand transfer (ST) reactions catalyzed by virus integrase (IN). Raltegravir (RAL), commonly used in AIDS therapy, belongs to the family of IN ST inhibitors (INSTIs) acting on IN-viral DNA complexes (intasomes). However, studies show that RAL fails to bind IN alone, but nothing has been reported on the behaviour of RAL toward free viral DNA. Here, we assessed whether free viral DNA could be a primary target for RAL, assuming that the DNA molecule is a receptor for a huge number of pharmacological agents. Optical spectroscopy, molecular dynamics and free energy calculations, showed that RAL is a tight binder of both processed and unprocessed LTR (long terminal repeat) ends. Complex formation involved mainly van der Waals forces and was enthalpy driven. Dissociation constants (Kds) revealed that RAL affinity for unbound LTRs was stronger than for bound LTRs. Moreover, Kd value for binding of RAL to LTRs and IC50 value (half concentration for inhibition) were in same range, suggesting that RAL binding to DNA and ST inhibition are correlated events. Accommodation of RAL into terminal base-pairs of unprocessed LTR is facilitated by an extensive end fraying that lowers the RAL binding energy barrier. The RAL binding entails a weak damping of fraying and correlatively of 3'-P inhibition. Noteworthy, present calculated RAL structures bound to free viral DNA resemble those found in RAL-intasome crystals, especially concerning the contacts between the fluorobenzyl group and the conserved 5'C(4)pA(3)3' step. We propose that RAL inhibits IN, in binding first unprocessed DNA. Similarly to anticancer drug poisons acting on topoisomerases, its interaction with DNA does not alter the cut, but blocks the subsequent joining reaction. We also speculate that INSTIs having viral DNA rather IN as main target could induce less resistance.
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Affiliation(s)
- Farah F. Ammar
- LBPA, UMR8113 du CNRS, Ecole Normale Supérieure de Cachan, Cedex, Cachan, France
- Unité de Biochimie, Département SVT, Faculté des Sciences, Université Saint-Joseph, CST-Mar Roukoz, Beyrouth, Liban
| | - Safwat Abdel-Azeim
- LBPA, UMR8113 du CNRS, Ecole Normale Supérieure de Cachan, Cedex, Cachan, France
| | - Loussinée Zargarian
- LBPA, UMR8113 du CNRS, Ecole Normale Supérieure de Cachan, Cedex, Cachan, France
| | - Zeina Hobaika
- Unité de Biochimie, Département SVT, Faculté des Sciences, Université Saint-Joseph, CST-Mar Roukoz, Beyrouth, Liban
| | - Richard G. Maroun
- Unité de Biochimie, Département SVT, Faculté des Sciences, Université Saint-Joseph, CST-Mar Roukoz, Beyrouth, Liban
| | - Serge Fermandjian
- LBPA, UMR8113 du CNRS, Ecole Normale Supérieure de Cachan, Cedex, Cachan, France
- * E-mail:
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Molecular dynamics approaches estimate the binding energy of HIV-1 integrase inhibitors and correlate with in vitro activity. Antimicrob Agents Chemother 2011; 56:411-9. [PMID: 22037850 DOI: 10.1128/aac.05292-11] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The design of novel integrase (IN) inhibitors has been aided by recent crystal structures revealing the binding mode of these compounds with a full-length prototype foamy virus (PFV) IN and synthetic viral DNA ends. Earlier docking studies relied on incomplete structures and did not include the contribution of the viral DNA to inhibitor binding. Using the structure of PFV IN as the starting point, we generated a model of the corresponding HIV-1 complex and developed a molecular dynamics (MD)-based approach that correlates with the in vitro activities of novel compounds. Four well-characterized compounds (raltegravir, elvitegravir, MK-0536, and dolutegravir) were used as a training set, and the data for their in vitro activity against the Y143R, N155H, and G140S/Q148H mutants were used in addition to the wild-type (WT) IN data. Three additional compounds were docked into the IN-DNA complex model and subjected to MD simulations. All three gave interaction potentials within 1 standard deviation of values estimated from the training set, and the most active compound was identified. Additional MD analysis of the raltegravir- and dolutegravir-bound complexes gave internal and interaction energy values that closely match the experimental binding energy of a compound related to raltegravir that has similar activity. These approaches can be used to gain a deeper understanding of the interactions of the inhibitors with the HIV-1 intasome and to identify promising scaffolds for novel integrase inhibitors, in particular, compounds that retain activity against a range of drug-resistant mutants, making it possible to streamline synthesis and testing.
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Dolutegravir (S/GSK1349572) exhibits significantly slower dissociation than raltegravir and elvitegravir from wild-type and integrase inhibitor-resistant HIV-1 integrase-DNA complexes. Antimicrob Agents Chemother 2011; 55:4552-9. [PMID: 21807982 DOI: 10.1128/aac.00157-11] [Citation(s) in RCA: 174] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The integrase inhibitor (INI) dolutegravir (DTG; S/GSK1349572) has significant activity against HIV-1 isolates with raltegravir (RAL)- and elvitegravir (ELV)-associated resistance mutations. As an initial step in characterizing the different resistance profiles of DTG, RAL, and ELV, we determined the dissociation rates of these INIs with integrase (IN)-DNA complexes containing a broad panel of IN proteins, including IN substitutions corresponding to signature RAL and ELV resistance mutations. DTG dissociates slowly from a wild-type IN-DNA complex at 37°C with an off-rate of 2.7 × 10(-6) s(-1) and a dissociative half-life (t(1/2)) of 71 h, significantly longer than the half-lives for RAL (8.8 h) and ELV (2.7 h). Prolonged binding (t(1/2), at least 5 h) was observed for DTG with IN-DNA complexes containing E92, Y143, Q148, and N155 substitutions. The addition of a second substitution to either Q148 or N155 typically resulted in an increase in the off-rate compared to that with the single substitution. For all of the IN substitutions tested, the off-rate of DTG from IN-DNA complexes was significantly slower (from 5 to 40 times slower) than the off-rate of RAL or ELV. These data are consistent with the potential for DTG to have a higher genetic barrier to resistance, provide evidence that the INI off-rate may be an important component of the mechanism of INI resistance, and suggest that the slow dissociation of DTG may contribute to its distinctive resistance profile.
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Li X, Krishnan L, Cherepanov P, Engelman A. Structural biology of retroviral DNA integration. Virology 2011; 411:194-205. [PMID: 21216426 DOI: 10.1016/j.virol.2010.12.008] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2010] [Accepted: 12/06/2010] [Indexed: 02/06/2023]
Abstract
Three-dimensional macromolecular structures shed critical light on biological mechanism and facilitate development of small molecule inhibitors. Clinical success of raltegravir, a potent inhibitor of HIV-1 integrase, demonstrated the utility of this viral DNA recombinase as an antiviral target. A variety of partial integrase structures reported in the past 16 years have been instrumental and very informative to the field. Nonetheless, because integrase protein fragments are unable to functionally engage the viral DNA substrate critical for strand transfer inhibitor binding, the early structures did little to materially impact drug development efforts. However, recent results based on prototype foamy virus integrase have fully reversed this trend, as a number of X-ray crystal structures of active integrase-DNA complexes revealed key mechanistic details and moreover established the foundation of HIV-1 integrase strand transfer inhibitor action. In this review we discuss the landmarks in the progress of integrase structural biology during the past 17 years.
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Affiliation(s)
- Xiang Li
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, MA 02115, USA
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Effect of raltegravir resistance mutations in HIV-1 integrase on viral fitness. J Acquir Immune Defic Syndr 2010; 55:148-55. [PMID: 20634701 DOI: 10.1097/qai.0b013e3181e9a87a] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Raltegravir resistance is conferred by mutations at integrase codons 143, 148, and 155 together with associated secondary mutations. The N155H mutants emerge first, and are eventually replaced by Q148H mutants, usually in combination with G140S. These mutations have different effects on susceptibility and replication capacity, but data on the relative fitness of RAL-resistant viruses are limited. To understand the impact of the different RAL resistance pathways on viral fitness, mutations at integrase codons 74, 92, 138, 140, 148, 155, and/or 163 were introduced into HIV-1NL4-3 by site-directed mutagenesis and expressed in recombinant viruses. Relative fitness and drug susceptibility were determined in the absence or presence of RAL. In the absence of drug, RAL-resistant mutants were less fit than wild type, and the Q148H mutant was significantly less fit than the N155H mutant. Fitness was partially restored by the presence of additional RAL resistance mutations at positions G140S and E92Q or E138K, respectively. In the presence of RAL, the N155H mutant remained fitter than the Q148H mutant, but the G140S/Q148H double mutant was fitter than single mutants or the E92Q/N155H double mutant. These findings correspond well with the clinical trials data and help explain the temporal pattern of RAL resistance evolution.
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Lewis MG, Norelli S, Collins M, Barreca ML, Iraci N, Chirullo B, Yalley-Ogunro J, Greenhouse J, Titti F, Garaci E, Savarino A. Response of a simian immunodeficiency virus (SIVmac251) to raltegravir: a basis for a new treatment for simian AIDS and an animal model for studying lentiviral persistence during antiretroviral therapy. Retrovirology 2010; 7:21. [PMID: 20233398 PMCID: PMC2853490 DOI: 10.1186/1742-4690-7-21] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2009] [Accepted: 03/16/2010] [Indexed: 01/02/2023] Open
Abstract
Background In this study we successfully created a new approach to ART in SIVmac251 infected nonhuman primates. This drug regimen is entirely based on drugs affecting the pre-integration stages of replication and consists of only two nucleotidic/nucleosidic reverse transcriptase inhibitors (Nt/NRTIs) and raltegravir, a promising new drug belonging to the integrase strand transfer inhibitor (INSTI) class. Results In acutely infected human lymphoid CD4+ T-cell lines MT-4 and CEMx174, SIVmac251 replication was efficiently inhibited by raltegravir, which showed an EC90 in the low nanomolar range. This result was confirmed in primary macaque PBMCs and enriched CD4+ T cell fractions. In vivo monotherapy with raltegravir for only ten days resulted in reproducible decreases in viral load in two different groups of animals. When emtricitabine (FTC) and tenofovir (PMPA) were added to treatment, undetectable viral load was reached in two weeks, and a parallel increase in CD4 counts was observed. In contrast, the levels of proviral DNA did not change significantly during the treatment period, thus showing persistence of this lentiviral reservoir during therapy. Conclusions In line with the high conservation of the three main amino acids Y143, Q148 and N155 (responsible for raltegravir binding) and molecular docking simulations showing similar binding modes of raltegravir at the SIVmac251 and HIV-1 IN active sites, raltegravir is capable of inhibiting SIVmac251 replication both in tissue culture and in vivo. This finding may help to develop effective ART regimens for the simian AIDS model entirely based on drugs adopted for treatment in humans. This ART-treated AIDS nonhuman primate model could be employed to find possible strategies for virus eradication from the body.
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Affiliation(s)
- Mark G Lewis
- Department of Infectious, Parasitic and Immune-mediated Diseases, Istituto Superiore di Sanità, Viale Regina Elena, 299, 00161, Rome, Italy.
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Carayon K, Leh H, Henry E, Simon F, Mouscadet JF, Deprez E. A cooperative and specific DNA-binding mode of HIV-1 integrase depends on the nature of the metallic cofactor and involves the zinc-containing N-terminal domain. Nucleic Acids Res 2010; 38:3692-708. [PMID: 20164093 PMCID: PMC2887959 DOI: 10.1093/nar/gkq087] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
HIV-1 integrase catalyzes the insertion of the viral genome into chromosomal DNA. We characterized the structural determinants of the 3′-processing reaction specificity—the first reaction of the integration process—at the DNA-binding level. We found that the integrase N-terminal domain, containing a pseudo zinc-finger motif, plays a key role, at least indirectly, in the formation of specific integrase–DNA contacts. This motif mediates a cooperative DNA binding of integrase that occurs only with the cognate/viral DNA sequence and the physiologically relevant Mg2+ cofactor. The DNA-binding was essentially non-cooperative with Mn2+ or using non-specific/random sequences, regardless of the metallic cofactor. 2,2′-Dithiobisbenzamide-1 induced zinc ejection from integrase by covalently targeting the zinc-finger motif, and significantly decreased the Hill coefficient of the Mg2+-mediated integrase–DNA interaction, without affecting the overall affinity. Concomitantly, 2,2′-dithiobisbenzamide-1 severely impaired 3′-processing (IC50 = 11–15 nM), suggesting that zinc ejection primarily perturbs the nature of the active integrase oligomer. A less specific and weaker catalytic effect of 2,2′-dithiobisbenzamide-1 is mediated by Cys 56 in the catalytic core and, notably, accounts for the weaker inhibition of the non-cooperative Mn2+-dependent 3′-processing. Our data show that the cooperative DNA-binding mode is strongly related to the sequence-specific DNA-binding, and depends on the simultaneous presence of the Mg2+ cofactor and the zinc effector.
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Affiliation(s)
- Kevin Carayon
- LBPA, CNRS, Ecole Normale Supérieure de Cachan, 61 av. du Président Wilson, 94235 Cachan, France
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Marchand C, Maddali K, Métifiot M, Pommier Y. HIV-1 IN inhibitors: 2010 update and perspectives. Curr Top Med Chem 2010; 9:1016-37. [PMID: 19747122 DOI: 10.2174/156802609789630910] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2009] [Accepted: 06/13/2009] [Indexed: 12/29/2022]
Abstract
Integrase (IN) is the newest validated target against AIDS and retroviral infections. The remarkable activity of raltegravir (Isentress((R))) led to its rapid approval by the FDA in 2007 as the first IN inhibitor. Several other IN strand transfer inhibitors (STIs) are in development with the primary goal to overcome resistance due to the rapid occurrence of IN mutations in raltegravir-treated patients. Thus, many scientists and drug companies are actively pursuing clinically useful IN inhibitors. The objective of this review is to provide an update on the IN inhibitors reported in the last two years, including second generation STI, recently developed hydroxylated aromatics, natural products, peptide, antibody and oligonucleotide inhibitors. Additionally, the targeting of IN cofactors such as LEDGF and Vpr will be discussed as novel strategies for the treatment of AIDS.
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Affiliation(s)
- Christophe Marchand
- Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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Barreca ML, Iraci N, De Luca L, Chimirri A. Induced-fit docking approach provides insight into the binding mode and mechanism of action of HIV-1 integrase inhibitors. ChemMedChem 2009; 4:1446-56. [PMID: 19544345 DOI: 10.1002/cmdc.200900166] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
A three-dimensional model of a complex between HIV-1 integrase (IN), viral DNA, and metal ions that we recently built was used as a target for a docking method (induced-fit docking, IFD) that accurately predicts ligand binding modes and concomitant structural changes in the receptor. Six different well-known integrase strand transfer inhibitors (INSTIs): L-708,906, L-731,988, S-1360, L-870,810, raltegravir, and elvitegravir were thus used as ligands for our docking simulations. The obtained IFD results are consistent with the mechanism of action proposed for this class of IN inhibitors, that is, metal chelating/binding agents. This study affords new insight into the possible mechanism of inhibition and binding conformations for INSTIs. The impact on our hypothesis of specific mutations associated with IN inhibitor resistance was also evaluated. All these findings might have implications for integrase-directed HIV-1 drug discovery efforts.
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Affiliation(s)
- Maria Letizia Barreca
- Dipartimento di Chimica e Tecnologia del Farmaco, Facoltà di Farmacia, Università di Perugia, Via del Liceo 1, 06123 Perugia, Italy.
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Mirambeau G. [How proviral DNA is integrated into the host cell DNA and how this process can be inhibited]. Enferm Infecc Microbiol Clin 2009; 26 Suppl 12:11-6. [PMID: 19572420 DOI: 10.1016/s0213-005x(08)76567-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The HIV replication cycle passes through a stage of integrating proviral DNA into the cell's DNA. In this process, the viral enzyme, integrase, catalyses two reactions. The first reaction, which seems to occur in the cytoplasm, involves 3'-end processing, in which two nucleotides are removed from the 3' ends of the viral DNA by integrase. The second reaction, which occurs in the nucleus, involves the strand transfer reaction, catalyzed by integrase, in which the recessed 3' ends of the viral DNA are joined to the protruding 5' ends in the target DNA. Although this activity has not yet been completely defined and the structure of the active form of integrase, probably a tetramer, has not been resolved, drugs of the diketoacid (DKA) family have been found. These drugs are highly potent inhibitors of the second phase, the strand transfer reaction. Through a series of optimizations, a highly effective molecule for clinical use, raltegravir, has been achieved. The present article provides a summary of basic knowledge on integrase, as well as the activity and the modes of inhibition of this enzyme. Also discussed is the reduced, but nevertheless real, development of resistance to raltegravir, requiring second-generation integrase inhibitors to be designed.
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Affiliation(s)
- Gilles Mirambeau
- Unitat de Recerca de la Sida, Fundació Clinic-IDIBAPS, Pare Cientific de Barcelona, Universidad de Barcelona, Barcelona, España.
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30
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Catalytically-active complex of HIV-1 integrase with a viral DNA substrate binds anti-integrase drugs. Proc Natl Acad Sci U S A 2009; 106:8192-7. [PMID: 19416821 DOI: 10.1073/pnas.0811919106] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
HIV-1 integration into the host cell genome is a multistep process catalyzed by the virally-encoded integrase (IN) protein. In view of the difficulty of obtaining a stable DNA-bound IN at high concentration as required for structure determination, we selected IN-DNA complexes that form disulfide linkages between 5'-thiolated DNA and several single mutations to cysteine around the catalytic site of IN. Mild reducing conditions allowed for selection of the most thermodynamically-stable disulfide-linked species. The most stable complexes induce tetramer formation of IN, as happens during the physiological integration reaction, and are able to catalyze the strand transfer step of retroviral integration. One of these complexes also binds strand-transfer inhibitors of HIV antiviral drugs, making it uniquely valuable among the mutants of this set for understanding portions of the integration reaction. This novel complex may help define substrate interactions and delineate the mechanism of action of known integration inhibitors.
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Serrao E, Odde S, Ramkumar K, Neamati N. Erratum to: Raltegravir, elvitegravir, and metoogravir: the birth of "me-too" HIV-1 integrase inhibitors. Retrovirology 2009. [PMCID: PMC2672074 DOI: 10.1186/1742-4690-6-33] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Correction to Erik Serrao, Srinivas Odde, Kavya Ramkumar and Nouri Neamati: Raltegravir, elvitegravir, and metoogravir: the birth of "me-too" HIV-1 integrase inhibitors. Retrovirology 2009, 6:25. Since the recent publication of our article (Neamati, Retrovirology 2009, 6:25), we have noticed an error which we would like to correct and we would like to apologise to the readers for this mistake.
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32
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Garvey EP, Schwartz B, Gartland MJ, Lang S, Halsey W, Sathe G, Carter HL, Weaver KL. Potent inhibitors of HIV-1 integrase display a two-step, slow-binding inhibition mechanism which is absent in a drug-resistant T66I/M154I mutant. Biochemistry 2009; 48:1644-53. [PMID: 19178153 DOI: 10.1021/bi802141y] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Two-metal binding HIV-1 integrase inhibitors (INIs) are potent inhibitors of HIV-1 in vitro and in patients. We report here for the first time the kinetics of inhibition of integrase-catalyzed strand transfer. First, the IC(50) values for each of six structurally distinct INIs decreased when a preincubation was included: S-1360 (1.3 microM vs 0.12 microM), L-731,988 (130 nM vs 9 nM), L-870,810 (130 nM vs 4 nM), raltegravir (300 nM vs 9 nM), elvitegravir (90 nM vs 6 nM), and GSK364735 (90 nM vs 6 nM). When reactions with these INIs were initiated with integrase, progress curve analyses indicated time-dependent inhibition, which could be fitted to a two-step mechanism of binding. Overall fitted K(i) values matched the IC(50) values measured with a preincubation: S-1360 (0.17 microM), L-731,988 (34 nM), L-870,810 (2.4 nM), raltegravir (10 nM), elvitegravir (4.0 nM), and GSK364735 (2.5 nM). To begin to understand the mechanism for this slow onset of inhibition and its possible impact on drug resistance, studies of resistance mutations were initiated. T66I/M154I exhibited little if any time-dependent inhibition by any of the six INIs, as measured by differences in potency upon preincubation or by progress curve analysis. These data demonstrate that slow binding is a signature of two-metal binding INIs, and that the second slow step is required for full potency. We discuss a possible structural explanation of the second slow step of inhibition and also the relationship between loss of time-dependent inhibition and drug resistance of this important new class of HIV-1 antiretroviral drugs.
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Affiliation(s)
- Edward P Garvey
- Department of Virology, GlaxoSmithKline Pharmaceuticals, 5 Moore Drive, Research Triangle Park, North Carolina 27709-3398, USA.
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Langley DR, Samanta HK, Lin Z, Walker MA, Krystal MR, Dicker IB. The terminal (catalytic) adenosine of the HIV LTR controls the kinetics of binding and dissociation of HIV integrase strand transfer inhibitors. Biochemistry 2009; 47:13481-8. [PMID: 18991395 DOI: 10.1021/bi801372d] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Specific HIV integrase strand transfer inhibitors are thought to bind to the integrase active site, positioned to coordinate with two catalytic magnesium atoms in a pocket flanked by the end of the viral LTR. A structural role for the 3' terminus of the viral LTR in the inhibitor-bound state has not previously been examined. This study describes the kinetics of binding of a specific strand transfer inhibitor to integrase variants assembled with systematic changes to the terminal 3' adenosine. Kinetic experiments are consistent with a two-step binding model in which there are different functions for the terminal adenine base and the terminal deoxyribose sugar. Adenine seems to act as a "shield" which retards the rate of inhibitor association with the integrase active site, possibly by acting as an internal competitive inhibitor. The terminal deoxyribose is responsible for retarding the rate of inhibitor dissociation, either by sterically blocking inhibitor egress or by a direct interaction with the bound inhibitor. These findings further our understanding of the details of the inhibitor binding site of specific strand transfer inhibitors.
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Affiliation(s)
- David R Langley
- Department of Computer Assisted Drug Design, Bristol-Myers Squibb Research & Development, Wallingford, Connecticut 06492, USA
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Pandey KK, Grandgenett DP. HIV-1 Integrase Strand Transfer Inhibitors: Novel Insights into their Mechanism of Action. ACTA ACUST UNITED AC 2008; 2:11-16. [PMID: 19915684 DOI: 10.4137/rrt.s1081] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Human immunodefi ciency virus type-1 integrase (IN) is a new and novel target for inhibitors. Strand transfer inhibitors effectively prevent concerted integration of viral DNA by IN into the host chromosomes. Raltegravir is the fi rst approved strand transfer inhibitor for the treatment of HIV-1/AIDS. We propose a mechanistic hypothesis as to "when and where" these inhibitors are active in virus-infected cells. Using native agarose gel electrophoresis, we identified a transient synaptic complex (SC) wherein IN non-covalently juxtaposes two viral DNA ends. SC possesses many properties associated with the cytoplasmic preintegration complex (PIC) in infected cells, including concerted integration. Our results show that the strand transfer inhibitors effectively "trap" or inactivate the SC preventing concerted integration. It follows that the IN-viral DNA complex is "trapped" by the inhibitors via a transient intermediate within the cytosolic PIC before entry into the nucleus.
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Resistance mutations in human immunodeficiency virus type 1 integrase selected with elvitegravir confer reduced susceptibility to a wide range of integrase inhibitors. J Virol 2008; 82:10366-74. [PMID: 18715920 DOI: 10.1128/jvi.00470-08] [Citation(s) in RCA: 138] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Integration of viral DNA into the host chromosome is an essential step in the life cycle of retroviruses and is facilitated by the viral integrase enzyme. The first generation of integrase inhibitors recently approved or currently in late-stage clinical trials shows great promise for the treatment of human immunodeficiency virus (HIV) infection, but virus is expected to develop resistance to these drugs. Therefore, we used a novel resistance selection protocol to follow the emergence of resistant HIV in the presence of the integrase inhibitor elvitegravir (GS-9137). We find the primary resistance-conferring mutations to be Q148R, E92Q, and T66I and demonstrate that they confer a reduction in susceptibility not only to elvitegravir but also to raltegravir (MK-0518) and other integrase inhibitors. The locations of the mutations are highlighted in the catalytic sites of integrase, and we correlate the mutations with expected drug-protein contacts. In addition, mutations that do not confer reduced susceptibility when present alone (H114Y, L74M, R20K, A128T, E138K, and S230R) are also discussed in relation to their position in the catalytic core domain and their proximity to known structural features of integrase. These data broaden the understanding of antiviral resistance against integrase inhibitors and may give insight facilitating the discovery of second-generation compounds.
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Delelis O, Carayon K, Guiot E, Leh H, Tauc P, Brochon JC, Mouscadet JF, Deprez E. Insight into the integrase-DNA recognition mechanism. A specific DNA-binding mode revealed by an enzymatically labeled integrase. J Biol Chem 2008; 283:27838-27849. [PMID: 18697740 DOI: 10.1074/jbc.m803257200] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Integration catalyzed by integrase (IN) is a key process in the retrovirus life cycle. Many biochemical or structural human immunodeficiency virus, type 1 (HIV-1) IN studies have been severely impeded by its propensity to aggregate. We characterized a retroviral IN (primate foamy virus (PFV-1)) that displays a solubility profile different from that of HIV-1 IN. Using various techniques, including fluorescence correlation spectroscopy, time-resolved fluorescence anisotropy, and size exclusion chromatography, we identified a monomer-dimer equilibrium for the protein alone, with a half-transition concentration of 20-30 mum. We performed specific enzymatic labeling of PFV-1 IN and measured the fluorescence resonance energy transfer between carboxytetramethylrhodamine-labeled IN and fluorescein-labeled DNA substrates. FRET and fluorescence anisotropy highlight the preferential binding of PFV-1 IN to the 3'-end processing site. Sequence-specific DNA binding was not observed with HIV-1 IN, suggesting that the intrinsic ability of retroviral INs to bind preferentially to the processing site is highly underestimated in the presence of aggregates. IN is in a dimeric state for 3'-processing on short DNA substrates, whereas IN polymerization, mediated by nonspecific contacts at internal DNA positions, occurs on longer DNAs. Additionally, aggregation, mediated by nonspecific IN-IN interactions, occurs preferentially with short DNAs at high IN/DNA ratios. The presence of either higher order complex is detrimental for specific activity. Ionic strength favors catalytically competent over higher order complexes by selectively disrupting nonspecific IN-IN interactions. This counteracting effect was not observed with polymerization. The synergic effect on the selection of specific/competent complexes, obtained by using short DNA substrates under high salt conditions, may have important implications for further structural studies in IN.DNA complexes.
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Affiliation(s)
- Olivier Delelis
- Laboratoire de Biologie et Pharmacologie Appliquée, CNRS, Ecole Normale Superieure Cachan, Institut d'Alembert, 61 Ave. du Président Wilson, 94235 Cachan, France
| | - Kevin Carayon
- Laboratoire de Biologie et Pharmacologie Appliquée, CNRS, Ecole Normale Superieure Cachan, Institut d'Alembert, 61 Ave. du Président Wilson, 94235 Cachan, France
| | - Elvire Guiot
- Laboratoire de Biologie et Pharmacologie Appliquée, CNRS, Ecole Normale Superieure Cachan, Institut d'Alembert, 61 Ave. du Président Wilson, 94235 Cachan, France
| | - Hervé Leh
- Laboratoire de Biologie et Pharmacologie Appliquée, CNRS, Ecole Normale Superieure Cachan, Institut d'Alembert, 61 Ave. du Président Wilson, 94235 Cachan, France
| | - Patrick Tauc
- Laboratoire de Biologie et Pharmacologie Appliquée, CNRS, Ecole Normale Superieure Cachan, Institut d'Alembert, 61 Ave. du Président Wilson, 94235 Cachan, France
| | - Jean-Claude Brochon
- Laboratoire de Biologie et Pharmacologie Appliquée, CNRS, Ecole Normale Superieure Cachan, Institut d'Alembert, 61 Ave. du Président Wilson, 94235 Cachan, France
| | - Jean-François Mouscadet
- Laboratoire de Biologie et Pharmacologie Appliquée, CNRS, Ecole Normale Superieure Cachan, Institut d'Alembert, 61 Ave. du Président Wilson, 94235 Cachan, France
| | - Eric Deprez
- Laboratoire de Biologie et Pharmacologie Appliquée, CNRS, Ecole Normale Superieure Cachan, Institut d'Alembert, 61 Ave. du Président Wilson, 94235 Cachan, France.
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Dicker IB, Terry B, Lin Z, Li Z, Bollini S, Samanta HK, Gali V, Walker MA, Krystal MR. Biochemical analysis of HIV-1 integrase variants resistant to strand transfer inhibitors. J Biol Chem 2008; 283:23599-609. [PMID: 18577511 DOI: 10.1074/jbc.m804213200] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
In this study, eight different HIV-1 integrase proteins containing mutations observed in strand transfer inhibitor-resistant viruses were expressed, purified, and used for detailed enzymatic analyses. All the variants examined were impaired for strand transfer activity compared with the wild type enzyme, with relative catalytic efficiencies (k(p)/K(m)) ranging from 0.6 to 50% of wild type. The origin of the reduced strand transfer efficiencies of the variant enzymes was predominantly because of poorer catalytic turnover (k(p)) values. However, smaller second-order effects were caused by up to 4-fold increases in K(m) values for target DNA utilization in some of the variants. All the variants were less efficient than the wild type enzyme in assembling on the viral long terminal repeat, as each variant required more protein than wild type to attain maximal activity. In addition, the variant integrases displayed up to 8-fold reductions in their catalytic efficiencies for 3'-processing. The Q148R variant was the most defective enzyme. The molecular basis for resistance of these enzymes was shown to be due to lower affinity binding of the strand transfer inhibitor to the integrase complex, a consequence of faster dissociation rates. In the case of the Q148R variant, the origin of reduced compound affinity lies in alterations to the active site that reduce the binding of a catalytically essential magnesium ion. Finally, except for T66I, variant viruses harboring the resistance-inducing substitutions were defective for viral integration.
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Affiliation(s)
- Ira B Dicker
- Department of Virology, Bristol-Myers Squibb Research and Development, Wallingford, CT 06492, USA.
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Savarino A, Pistello M, D'Ostilio D, Zabogli E, Taglia F, Mancini F, Ferro S, Matteucci D, De Luca L, Barreca ML, Ciervo A, Chimirri A, Ciccozzi M, Bendinelli M. Human immunodeficiency virus integrase inhibitors efficiently suppress feline immunodeficiency virus replication in vitro and provide a rationale to redesign antiretroviral treatment for feline AIDS. Retrovirology 2007; 4:79. [PMID: 17971219 PMCID: PMC2244644 DOI: 10.1186/1742-4690-4-79] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2007] [Accepted: 10/30/2007] [Indexed: 01/14/2023] Open
Abstract
Background Treatment of feline immunodeficiency virus (FIV) infection has been hampered by the absence of a specific combination antiretroviral treatment (ART). Integrase strand transfer inhibitors (INSTIs) are emerging as a promising new drug class for HIV-1 treatment, and we evaluated the possibility of inhibiting FIV replication using INSTIs. Methods Phylogenetic analysis of lentiviral integrase (IN) sequences was carried out using the PAUP* software. A theoretical three-dimensional structure of the FIV IN catalytic core domain (CCD) was obtained by homology modeling based on a crystal structure of HIV-1 IN CCD. The interaction of the transferred strand of viral DNA with the catalytic cavity of FIV IN was deduced from a crystal structure of a structurally similar transposase complexed with transposable DNA. Molecular docking simulations were conducted using a genetic algorithm (GOLD). Antiviral activity was tested in feline lymphoblastoid MBM cells acutely infected with the FIV Petaluma strain. Circular and total proviral DNA was quantified by real-time PCR. Results The calculated INSTI-binding sites were found to be nearly identical in FIV and HIV-1 IN CCDs. The close similarity of primate and feline lentivirus IN CCDs was also supported by phylogenetic analysis. In line with these bioinformatic analyses, FIV replication was efficiently inhibited in acutely infected cell cultures by three investigational INSTIs, designed for HIV-1 and belonging to different classes. Of note, the naphthyridine carboxamide INSTI, L-870,810 displayed an EC50 in the low nanomolar range. Inhibition of FIV integration in situ was shown by real-time PCR experiments that revealed accumulation of circular forms of FIV DNA within cells treated with L-870,810. Conclusion We report a drug class (other than nucleosidic reverse transcriptase inhibitors) that is capable of inhibiting FIV replication in vitro. The present study helped establish L-870,810, a compound successfully tested in human clinical trials, as one of the most potent anti-FIV agents ever tested in vitro. This finding may provide new avenues for treating FIV infection and contribute to the development of a small animal model mimicking the effects of ART in humans.
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Affiliation(s)
- Andrea Savarino
- Dept. of Infectious, Parasitic and Immune-mediated Diseases, Istituto Superiore di Sanità, Viale Regina Elena, 299, 00161, Rome, Italy.
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