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Flynn JK, Ellenberg P, Duncan R, Ellett A, Zhou J, Sterjovski J, Cashin K, Borm K, Gray LR, Lewis M, Jubb B, Westby M, Lee B, Lewin SR, Churchill M, Roche M, Gorry PR. Analysis of Clinical HIV-1 Strains with Resistance to Maraviroc Reveals Strain-Specific Resistance Mutations, Variable Degrees of Resistance, and Minimal Cross-Resistance to Other CCR5 Antagonists. AIDS Res Hum Retroviruses 2017; 33:1220-1235. [PMID: 28797170 DOI: 10.1089/aid.2017.0097] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Maraviroc (MVC) is an allosteric inhibitor of human immunodeficiency virus type 1 (HIV-1) entry, and is the only CCR5 antagonist licensed for use as an anti-HIV-1 therapeutic. It acts by altering the conformation of the CCR5 extracellular loops, rendering CCR5 unrecognizable by the HIV-1 envelope (Env) glycoproteins. This study aimed to understand the mechanisms underlying the development of MVC resistance in HIV-1-infected patients. To do this, we obtained longitudinal plasma samples from eight subjects who experienced treatment failure with phenotypically verified, CCR5-tropic MVC resistance. We then cloned and characterized HIV-1 Envs (n = 77) from plasma of pretreatment (n = 36) and treatment failure (n = 41) samples. Our results showed variation in the magnitude of MVC resistance as measured by reductions in maximal percent inhibition of Env-pseudotyped viruses, which was more pronounced in 293-Affinofile cells compared to other cells with similar levels of CCR5 expression. Amino acid determinants of MVC resistance localized to the V3 Env region and were strain specific. We also observed minimal cross-resistance to other CCR5 antagonists by MVC-resistant strains. We conclude that 293-Affinofile cells are highly sensitive for detecting and measuring MVC resistance through a mechanism that is CCR5-dependent yet independent of CCR5 expression levels. The strain-specific nature of resistance mutations suggests that sequence-based diagnostics and prognostics will need to be more sophisticated than simple position scoring to be useful for managing resistance in subjects taking MVC. Finally, the minimal levels of cross-resistance suggests that recognition of the MVC-modified form of CCR5 does not necessarily lead to recognition of other antagonist-modified forms of CCR5.
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Affiliation(s)
- Jacqueline K. Flynn
- School of Health and Biomedical Sciences, College of Science, Engineering and Health, RMIT University, Melbourne, Australia
- Centre for Biomedical Research, Burnet Institute, Melbourne, Australia
| | - Paula Ellenberg
- School of Health and Biomedical Sciences, College of Science, Engineering and Health, RMIT University, Melbourne, Australia
- Centre for Biomedical Research, Burnet Institute, Melbourne, Australia
| | - Renee Duncan
- Centre for Biomedical Research, Burnet Institute, Melbourne, Australia
| | - Anne Ellett
- Centre for Biomedical Research, Burnet Institute, Melbourne, Australia
| | - Jingling Zhou
- School of Health and Biomedical Sciences, College of Science, Engineering and Health, RMIT University, Melbourne, Australia
- Centre for Biomedical Research, Burnet Institute, Melbourne, Australia
| | - Jasminka Sterjovski
- Centre for Biomedical Research, Burnet Institute, Melbourne, Australia
- The Peter Doherty Institute for Infection and Immunity, University of Melbourne and Royal Melbourne Hospital, Melbourne, Australia
| | - Kieran Cashin
- School of Health and Biomedical Sciences, College of Science, Engineering and Health, RMIT University, Melbourne, Australia
- Centre for Biomedical Research, Burnet Institute, Melbourne, Australia
| | - Katharina Borm
- Centre for Biomedical Research, Burnet Institute, Melbourne, Australia
- Department of Microbiology, La Trobe University, Melbourne, Australia
| | - Lachlan R Gray
- Centre for Biomedical Research, Burnet Institute, Melbourne, Australia
| | - Marilyn Lewis
- Pfizer Global Research and Development, Sandwich, United Kingdom
| | - Becky Jubb
- Pfizer Global Research and Development, Sandwich, United Kingdom
| | - Mike Westby
- Centauri Therapeutics, Ltd., Sandwich, United Kingdom
| | - Benhur Lee
- Icahn School of Medicine at Mount Sinai, New York, New York
| | - Sharon R Lewin
- The Peter Doherty Institute for Infection and Immunity, University of Melbourne and Royal Melbourne Hospital, Melbourne, Australia
| | - Melissa Churchill
- School of Health and Biomedical Sciences, College of Science, Engineering and Health, RMIT University, Melbourne, Australia
- Centre for Biomedical Research, Burnet Institute, Melbourne, Australia
- Department of Microbiology, Monash University, Melbourne, Australia
| | - Michael Roche
- School of Health and Biomedical Sciences, College of Science, Engineering and Health, RMIT University, Melbourne, Australia
- Centre for Biomedical Research, Burnet Institute, Melbourne, Australia
- The Peter Doherty Institute for Infection and Immunity, University of Melbourne and Royal Melbourne Hospital, Melbourne, Australia
| | - Paul R. Gorry
- School of Health and Biomedical Sciences, College of Science, Engineering and Health, RMIT University, Melbourne, Australia
- Centre for Biomedical Research, Burnet Institute, Melbourne, Australia
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Espy N, Pacheco B, Sodroski J. Adaptation of HIV-1 to cells with low expression of the CCR5 coreceptor. Virology 2017; 508:90-107. [PMID: 28521215 DOI: 10.1016/j.virol.2017.04.033] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 04/27/2017] [Accepted: 04/28/2017] [Indexed: 11/19/2022]
Abstract
The binding of the human immunodeficiency virus (HIV-1) envelope glycoprotein (Env) trimer ((gp120/gp41)3) to the receptors CD4 and CCR5 triggers virus entry into host cells. To identify Env regions that respond to CCR5 binding, HIV-1 was serially passaged on a CD4-positive canine cell line expressing progressively lower levels of CCR5. HIV-1 replication was observed in cells expressing ~1300 CCR5 molecules/cell. Env changes that conferred this low-CCR5 replication phenotype were located outside of the known CCR5-binding region of the gp120 Env subunit and did not apparently increase CCR5 binding affinity. The adaptation-associated changes, located in the gp120 α1 helix and in the gp41 HR1 heptad repeat and membrane-proximal external region (MPER), enhanced HIV-1 replication in cells at all levels of CCR5 expression. The adapted Envs exhibited a greater propensity to undergo conformational changes, as evidenced by increased exposure of conserved regions near the CD4- and CCR5-binding sites.
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Affiliation(s)
- Nicole Espy
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Beatriz Pacheco
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA, USA; Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, USA
| | - Joseph Sodroski
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA; Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA, USA; Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, USA.
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3
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Kim MB, Giesler KE, Tahirovic YA, Truax VM, Liotta DC, Wilson LJ. CCR5 receptor antagonists in preclinical to phase II clinical development for treatment of HIV. Expert Opin Investig Drugs 2016; 25:1377-1392. [PMID: 27791451 PMCID: PMC5776690 DOI: 10.1080/13543784.2016.1254615] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
INTRODUCTION The chemokine receptor CCR5 has garnered significant attention in recent years as a target to treat HIV infection largely due to the approval and success of the drug Maraviroc. The side effects and inefficiencies with other first generation agents led to failed clinical trials, prompting the development of newer CCR5 antagonists. Areas covered: This review aims to survey the current status of 'next generation' CCR5 antagonists in the preclinical pipeline with an emphasis on emerging agents for the treatment of HIV infection. These efforts have culminated in the identification of advanced second-generation agents to reach the clinic and the dual CCR5/CCR2 antagonist Cenicriviroc as the most advanced currently in phase II clinical studies. Expert opinion: The clinical success of CCR5 inhibitors for treatment of HIV infection has rested largely on studies of Maraviroc and a second-generation dual CCR5/CCR2 antagonist Cenicriviroc. Although research efforts identified several promising preclinical candidates, these were dropped during early clinical studies. Despite patient access to Maraviroc, there is insufficient enthusiasm surrounding its use as front-line therapy for treatment of HIV. The non-HIV infection related development activities for Maraviroc and Cenicriviroc may help drive future interests.
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Affiliation(s)
- Michelle B Kim
- a Department of Chemistry , Emory University , Atlanta , GA , USA
| | - Kyle E Giesler
- a Department of Chemistry , Emory University , Atlanta , GA , USA
| | | | - Valarie M Truax
- a Department of Chemistry , Emory University , Atlanta , GA , USA
| | - Dennis C Liotta
- a Department of Chemistry , Emory University , Atlanta , GA , USA
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Reduced Baseline Sensitivity to Maraviroc Inhibition Among R5 HIV-1 Isolates From Individuals With Severe Immunodeficiency. J Acquir Immune Defic Syndr 2016; 71:e79-82. [PMID: 26492461 PMCID: PMC4770368 DOI: 10.1097/qai.0000000000000873] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Supplemental Digital Content is Available in the Text.
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Latinovic OS, Medina-Moreno S, Schneider K, Gohain N, Zapata J, Pazgier M, Reitz M, Bryant J, Redfield RR. Full Length Single Chain Fc Protein (FLSC IgG1) as a Potent Antiviral Therapy Candidate: Implications for In Vivo Studies. AIDS Res Hum Retroviruses 2016; 32:178-86. [PMID: 26059995 DOI: 10.1089/aid.2015.0020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
We have previously shown that FLSC, a chimeric protein containing HIV-1BAL gp120 and the D1 and D2 domains of human CD4, blocks the binding and entry of HIV-1 into target cells by occluding CCR5, the major HIV-1 coreceptor. In an effort to improve the antiviral potential of FLSC, we fused it with the hinge-CH2-CH3 region of human IgG1. The IgG moiety should increase both the affinity and stability in vivo of FLSC, due to the resultant bivalency and an extended serum half-life, thereby increasing its antiviral potency. We previously showed that (FLSC) IgG1 indeed had greater antiviral activity against T cell infections. Here we extend these results to macrophages, for which (FLSC) IgG1 has a more potent antiviral activity than FLSC alone, due in part to its higher binding affinity for CCR5. We also test both compounds in a relevant humanized mouse model and show that, as anticipated, the IgG1 moiety confers a greatly extended half-life. These data, taken together with previous results, suggest potential clinical utility for (FLSC) IgG1 and support further developmental work toward eventual clinical trials.
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Affiliation(s)
- Olga S. Latinovic
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Sandra Medina-Moreno
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Kate Schneider
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Neelakshi Gohain
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Juan Zapata
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Marzena Pazgier
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Marvin Reitz
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland
- School of Medicine, University of Maryland School of Medicine, Baltimore, Maryland
| | - Joseph Bryant
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland
- Department of Pathology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Robert R. Redfield
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland
- School of Medicine, University of Maryland School of Medicine, Baltimore, Maryland
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Characterizing the Diverse Mutational Pathways Associated with R5-Tropic Maraviroc Resistance: HIV-1 That Uses the Drug-Bound CCR5 Coreceptor. J Virol 2015; 89:11457-72. [PMID: 26339063 PMCID: PMC4645647 DOI: 10.1128/jvi.01384-15] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 08/28/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Entry inhibitors represent a potent class of antiretroviral drugs that target a host cell protein, CCR5, an HIV-1 entry coreceptor, and not viral protein. Lack of sensitivity can occur due to preexisting virus that uses the CXCR4 coreceptor, while true resistance occurs through viral adaptation to use a drug-bound CCR5 coreceptor. To understand this R5 resistance pathway, we analyzed >500 envelope protein sequences and phenotypes from viruses of 20 patients from the clinical trials MOTIVATE 1 and 2, in which treatment-experienced patients received maraviroc plus optimized background therapy. The resistant viral population was phylogenetically distinct and associated with a genetic bottleneck in each patient, consistent with de novo emergence of resistance. Recombination analysis showed that the C2-V3-C3 region tends to genotypically correspond to the recombinant's phenotype, indicating its primary importance in conferring resistance. Between patients, there was a notable lack of commonality in the specific sites conferring resistance, confirming the unusual nature of R5-tropic resistance. We used coevolutionary and positive-selection analyses to characterize the genotypic determinants of resistance and found that (i) there are complicated covariation networks, indicating frequent coevolutionary/compensatory changes in the context of protein structure; (ii) covarying sites under positive selection are enriched in resistant viruses; (iii) CD4 binding sites form part of a unique covariation network independent of the V3 loop; and (iv) the covariation network formed between the V3 loop and other regions of gp120 and gp41 intersects sites involved in glycosylation and protein secretion. These results demonstrate that while envelope sequence mutations are the key to conferring maraviroc resistance, the specific changes involved are context dependent and thus inherently unpredictable. IMPORTANCE The entry inhibitor drug maraviroc makes the cell coreceptor CCR5 unavailable for use by HIV-1 and is now used in combination antiretroviral therapy. Treatment failure with drug-resistant virus is particularly interesting because it tends to be rare, with lack of sensitivity usually associated with the presence of CXCR4-using virus (CXCR4 is the main alternative coreceptor HIV-1 uses, in addition to CD4). We analyzed envelope sequences from HIV-1, obtained from 20 patients who enrolled in maraviroc clinical trials and experienced treatment failure, without detection of CXCR4-using virus. Evolutionary analysis was employed to identify molecular changes that confer maraviroc resistance. We found that in these individuals, resistant viruses form a distinct population that evolved once and was successful as a result of drug pressure. Further evolutionary analysis placed the complex network of interdependent mutational changes into functional groups that help explain the impediments to the emergence of maraviroc-associated R5 drug resistance.
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Abstract
ABSTRACT HIV resistance against currently approved entry inhibitors, the chemokine receptor-5 (CCR5) antagonist maraviroc and the fusion inhibitor enfuvirtide (T-20), manifests in a complex manner that is distinct from the resistance patterns against other classes of antiretroviral drugs. Several attachment and fusion inhibitors are currently under various stages of development. Whereas CCR5 co-receptor antagonists have been widely studied until now, because patients who lack CCR5 are healthy and protected to some extent from HIV-infection, CXCR4-antagonist development has been slower, due to limited antiviral activity and potential toxicity given that CXCR4 may have essential cellular functions. Novel fusion inhibitor development is focusing on orally available small-molecule inhibitors that might replace T-20, which needs to be administered by subcutaneous injection.
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Affiliation(s)
- Victor G Kramer
- McGill AIDS Centre, Lady Davis Institute, Jewish General Hospital, Montreal, QC, Canada
- Department of Experimental Medicine, McGill University, Montreal, QC, Canada
| | - Mark A Wainberg
- McGill AIDS Centre, Lady Davis Institute, Jewish General Hospital, Montreal, QC, Canada
- Department of Experimental Medicine, McGill University, Montreal, QC, Canada
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8
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Montagna C, De Crignis E, Bon I, Re MC, Mezzaroma I, Turriziani O, Graziosi C, Antonelli G. V3 net charge: additional tool in HIV-1 tropism prediction. AIDS Res Hum Retroviruses 2014; 30:1203-12. [PMID: 25322170 DOI: 10.1089/aid.2014.0006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Genotype-based algorithms are valuable tools for the identification of patients eligible for CCR5 inhibitors administration in clinical practice. Among the available methods, geno2pheno[coreceptor] (G2P) is the most used online tool for tropism prediction. This study was conceived to assess if the combination of G2P prediction with V3 peptide net charge (NC) value could improve the accuracy of tropism prediction. A total of 172 V3 bulk sequences from 143 patients were analyzed by G2P and NC values. A phenotypic assay was performed by cloning the complete env gene and tropism determination was assessed on U87_CCR5(+)/CXCR4(+) cells. Sequences were stratified according to the agreement between NC values and G2P results. Of sequences predicted as X4 by G2P, 61% showed NC values higher than 5; similarly, 76% of sequences predicted as R5 by G2P had NC values below 4. Sequences with NC values between 4 and 5 were associated with different G2P predictions: 65% of samples were predicted as R5-tropic and 35% of sequences as X4-tropic. Sequences identified as X4 by NC value had at least one positive residue at positions known to be involved in tropism prediction and positive residues in position 32. These data supported the hypothesis that NC values between 4 and 5 could be associated with the presence of dual/mixed-tropic (DM) variants. The phenotypic assay performed on a subset of sequences confirmed the tropism prediction for concordant sequences and showed that NC values between 4 and 5 are associated with DM tropism. These results suggest that the combination of G2P and NC could increase the accuracy of tropism prediction. A more reliable identification of X4 variants would be useful for better selecting candidates for Maraviroc (MVC) administration, but also as a predictive marker in coreceptor switching, strongly associated with the phase of infection.
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Affiliation(s)
- Claudia Montagna
- Virology Section, Department of Molecular Medicine, Sapienza University, Rome, Italy
| | - Elisa De Crignis
- Division of Immunology and Allergy, Department of Medicine, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
| | - Isabella Bon
- Microbiology Section, Department of Experimental, Diagnostic and Specialty Medicine, School of Medicine, University of Bologna, Bologna, Italy
| | - Maria Carla Re
- Microbiology Section, Department of Experimental, Diagnostic and Specialty Medicine, School of Medicine, University of Bologna, Bologna, Italy
| | - Ivano Mezzaroma
- Department of Clinical Medicine, Sapienza University, Rome, Italy
| | - Ombretta Turriziani
- Virology Section, Department of Molecular Medicine, Sapienza University, Rome, Italy
| | - Cecilia Graziosi
- Division of Immunology and Allergy, Department of Medicine, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
| | - Guido Antonelli
- Virology Section, Department of Molecular Medicine, Sapienza University, Rome, Italy
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9
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Role of 3D Structures in Understanding, Predicting, and Designing Molecular Interactions in the Chemokine Receptor Family. ACTA ACUST UNITED AC 2014. [DOI: 10.1007/7355_2014_77] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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10
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Flanagan CA. Receptor Conformation and Constitutive Activity in CCR5 Chemokine Receptor Function and HIV Infection. ADVANCES IN PHARMACOLOGY 2014; 70:215-63. [DOI: 10.1016/b978-0-12-417197-8.00008-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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11
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Barmania F, Pepper MS. C-C chemokine receptor type five (CCR5): An emerging target for the control of HIV infection. Appl Transl Genom 2013; 2:3-16. [PMID: 27942440 PMCID: PMC5133339 DOI: 10.1016/j.atg.2013.05.004] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 05/19/2013] [Accepted: 05/21/2013] [Indexed: 12/25/2022]
Abstract
When HIV was initially discovered as the causative agent of AIDS, many expected to find a vaccine within a few years. This has however proven to be elusive; it has been approximately 30 years since HIV was first discovered, and a suitable vaccine is still not in effect. In 2009, a paper published by Hutter et al. reported on a bone marrow transplant performed on an HIV positive individual using stem cells that were derived from a donor who was homozygous for a mutation in the CCR5 gene known as CCR5 delta-32 (Δ32) (Hütter et al., 2009). The HIV positive individual became HIV negative and remained free of viral detection after transplantation despite having halted anti-retroviral (ARV) treatment. This review will focus on CCR5 as a key component in HIV immunity and will discuss the role of CCR5 in the control of HIV infection.
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Affiliation(s)
| | - Michael S. Pepper
- Corresponding author at: Dept. of Immunology, Faculty of Health Sciences, University of Pretoria, P.O. Box 2034, Pretoria 0001, South Africa. Tel.: + 27 12 319 2190; fax: + 27 12 319 2946.
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12
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Rudick JG, Laakso MM, Schloss AC, DeGrado WF. Template-constrained cyclic sulfopeptide HIV-1 entry inhibitors. Org Biomol Chem 2013; 11:7096-100. [PMID: 24065278 PMCID: PMC3889485 DOI: 10.1039/c3ob41395k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Template-constrained cyclic sulfopeptides that inhibit HIV-1 entry were rationally designed based on a loop from monoclonal antibody (mAb) 412d. A focused set of sulfopeptides was synthesized using Fmoc-Tyr(SO3DCV)-OH (DCV = 2,2-dichlorovinyl). Three cyclic sulfopeptides that inhibit entry of HIV-1 and complement the activity of known CCR5 antagonists were identified.
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Affiliation(s)
- Jonathan G. Rudick
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Meg M. Laakso
- Department Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ashley C. Schloss
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - William F. DeGrado
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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Shivatare SS, Chang SH, Tsai TI, Ren CT, Chuang HY, Hsu L, Lin CW, Li ST, Wu CY, Wong CH. Efficient convergent synthesis of bi-, tri-, and tetra-antennary complex type N-glycans and their HIV-1 antigenicity. J Am Chem Soc 2013; 135:15382-91. [PMID: 24032650 DOI: 10.1021/ja409097c] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The structural diversity of glycoproteins often comes from post-translational glycosylation with heterogeneous N-glycans. Understanding the complexity of glycans related to various biochemical processes demands a well-defined synthetic sugar library. We report herein a unified convergent strategy for the rapid production of bi-, tri-, and tetra-antennary complex type N-glycans with and without terminal N-acetylneuraminic acid residues connected via the α-2,6 or α-2,3 linkages. Moreover, using sialyltransferases to install sialic acid can minimize synthetic steps through the use of shared intermediates to simplify the complicated procedures associated with conventional sialic acid chemistry. Furthermore, these synthetic complex oligosaccharides were compiled to create a glycan array for the profiling of HIV-1 broadly neutralizing antibodies PG9 and PG16 that were isolated from HIV infected donors. From the study of antibody PG16, we identified potential natural and unnatural glycan ligands, which may facilitate the design of carbohydrate-based immunogens and hasten the HIV vaccine development.
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Affiliation(s)
- Sachin S Shivatare
- Genomics Research Center, Academia Sinica , 128 Academia Road, Section 2, Nankang, Taipei 115, Taiwan
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14
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Ping LH, Joseph SB, Anderson JA, Abrahams MR, Salazar-Gonzalez JF, Kincer LP, Treurnicht FK, Arney L, Ojeda S, Zhang M, Keys J, Potter EL, Chu H, Moore P, Salazar MG, Iyer S, Jabara C, Kirchherr J, Mapanje C, Ngandu N, Seoighe C, Hoffman I, Gao F, Tang Y, Labranche C, Lee B, Saville A, Vermeulen M, Fiscus S, Morris L, Karim SA, Haynes BF, Shaw GM, Korber BT, Hahn BH, Cohen MS, Montefiori D, Williamson C, Swanstrom R. Comparison of viral Env proteins from acute and chronic infections with subtype C human immunodeficiency virus type 1 identifies differences in glycosylation and CCR5 utilization and suggests a new strategy for immunogen design. J Virol 2013; 87:7218-33. [PMID: 23616655 PMCID: PMC3700278 DOI: 10.1128/jvi.03577-12] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Accepted: 04/15/2013] [Indexed: 12/18/2022] Open
Abstract
Understanding human immunodeficiency virus type 1 (HIV-1) transmission is central to developing effective prevention strategies, including a vaccine. We compared phenotypic and genetic variation in HIV-1 env genes from subjects in acute/early infection and subjects with chronic infections in the context of subtype C heterosexual transmission. We found that the transmitted viruses all used CCR5 and required high levels of CD4 to infect target cells, suggesting selection for replication in T cells and not macrophages after transmission. In addition, the transmitted viruses were more likely to use a maraviroc-sensitive conformation of CCR5, perhaps identifying a feature of the target T cell. We confirmed an earlier observation that the transmitted viruses were, on average, modestly underglycosylated relative to the viruses from chronically infected subjects. This difference was most pronounced in comparing the viruses in acutely infected men to those in chronically infected women. These features of the transmitted virus point to selective pressures during the transmission event. We did not observe a consistent difference either in heterologous neutralization sensitivity or in sensitivity to soluble CD4 between the two groups, suggesting similar conformations between viruses from acute and chronic infection. However, the presence or absence of glycosylation sites had differential effects on neutralization sensitivity for different antibodies. We suggest that the occasional absence of glycosylation sites encoded in the conserved regions of env, further reduced in transmitted viruses, could expose specific surface structures on the protein as antibody targets.
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Affiliation(s)
- Li-Hua Ping
- UNC Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Sarah B. Joseph
- UNC Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Jeffrey A. Anderson
- UNC Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Division of Infectious Diseases, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Melissa-Rose Abrahams
- Institute of Infectious Diseases and Molecular Medicine, Division of Medical Virology, University of Cape Town and National Health Laboratory Services, Cape Town, South Africa
| | | | - Laura P. Kincer
- UNC Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Florette K. Treurnicht
- Institute of Infectious Diseases and Molecular Medicine, Division of Medical Virology, University of Cape Town and National Health Laboratory Services, Cape Town, South Africa
| | - Leslie Arney
- UNC Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Suany Ojeda
- UNC Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Ming Zhang
- Theoretical Biology, Los Alamos National Laboratory, Los Alamos, New Mexico, USA
- Department of Epidemiology and Biostatistics, University of Georgia, Athens, Georgia, USA
| | - Jessica Keys
- UNC Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - E. Lake Potter
- UNC Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Haitao Chu
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Penny Moore
- Centre for HIV and STIs, National Institute for Communicable Diseases, Johannesburg, South Africa
| | - Maria G. Salazar
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Shilpa Iyer
- Departments of Medicine and Microbiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Cassandra Jabara
- UNC Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Jennifer Kirchherr
- Duke Human Vaccine Institute, Department of Medicine, Duke University, Durham, North Carolina, USA
| | | | - Nobubelo Ngandu
- Institute of Infectious Diseases and Molecular Medicine, Division of Medical Virology, University of Cape Town and National Health Laboratory Services, Cape Town, South Africa
| | | | - Irving Hoffman
- Division of Infectious Diseases, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Feng Gao
- Duke Human Vaccine Institute, Department of Medicine, Duke University, Durham, North Carolina, USA
| | - Yuyang Tang
- UNC Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Celia Labranche
- Department of Surgery, Duke University, Durham, North Carolina, USA
| | - Benhur Lee
- Department of Microbiology, Immunology and Molecular Genetics, University of California at Los Angeles, Los Angeles, California, USA
| | - Andrew Saville
- South African National Blood Service, Weltevreden Park, South Africa
| | - Marion Vermeulen
- South African National Blood Service, Weltevreden Park, South Africa
| | - Susan Fiscus
- UNC Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Lynn Morris
- Centre for HIV and STIs, National Institute for Communicable Diseases, Johannesburg, South Africa
| | - Salim Abdool Karim
- Center for AIDS Program Research in South Africa, Doris Duke Medical Research Institute, University of KwaZulu-Natal, Durban, South Africa
| | - Barton F. Haynes
- Duke Human Vaccine Institute, Department of Medicine, Duke University, Durham, North Carolina, USA
| | - George M. Shaw
- Departments of Medicine and Microbiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Bette T. Korber
- Los Alamos National Laboratory, Los Alamos, New Mexico, USA
- Santa Fe Institute, Santa Fe, New Mexico, USA
| | - Beatrice H. Hahn
- Departments of Medicine and Microbiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Myron S. Cohen
- UNC Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Division of Infectious Diseases, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - David Montefiori
- Department of Surgery, Duke University, Durham, North Carolina, USA
| | - Carolyn Williamson
- Institute of Infectious Diseases and Molecular Medicine, Division of Medical Virology, University of Cape Town and National Health Laboratory Services, Cape Town, South Africa
| | - Ronald Swanstrom
- UNC Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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15
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Yuan Y, Yokoyama M, Maeda Y, Terasawa H, Harada S, Sato H, Yusa K. Structure and dynamics of the gp120 V3 loop that confers noncompetitive resistance in R5 HIV-1(JR-FL) to maraviroc. PLoS One 2013; 8:e65115. [PMID: 23840315 PMCID: PMC3695986 DOI: 10.1371/journal.pone.0065115] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 04/21/2013] [Indexed: 12/22/2022] Open
Abstract
Maraviroc, an (HIV-1) entry inhibitor, binds to CCR5 and efficiently prevents R5 human immunodeficiency virus type 1 (HIV-1) from using CCR5 as a coreceptor for entry into CD4(+) cells. However, HIV-1 can elude maraviroc by using the drug-bound form of CCR5 as a coreceptor. This property is known as noncompetitive resistance. HIV-1(V3-M5) derived from HIV-1(JR-FLan) is a noncompetitive-resistant virus that contains five mutations (I304V/F312W/T314A/E317D/I318V) in the gp120 V3 loop alone. To obtain genetic and structural insights into maraviroc resistance in HIV-1, we performed here mutagenesis and computer-assisted structural study. A series of site-directed mutagenesis experiments demonstrated that combinations of V3 mutations are required for HIV-1(JR-FLan) to replicate in the presence of 1 µM maraviroc, and that a T199K mutation in the C2 region increases viral fitness in combination with V3 mutations. Molecular dynamic (MD) simulations of the gp120 outer domain V3 loop with or without the five mutations showed that the V3 mutations induced (i) changes in V3 configuration on the gp120 outer domain, (ii) reduction of an anti-parallel β-sheet in the V3 stem region, (iii) reduction in fluctuations of the V3 tip and stem regions, and (iv) a shift of the fluctuation site at the V3 base region. These results suggest that the HIV-1 gp120 V3 mutations that confer maraviroc resistance alter structure and dynamics of the V3 loop on the gp120 outer domain, and enable interactions between gp120 and the drug-bound form of CCR5.
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Affiliation(s)
- Yuzhe Yuan
- Transfusion Transmitted Diseases Center, Institute of Blood Transfusion, Chinese Academy of Medical Science, Chenghua District, Chengdu, Sichuan Province, P. R. China
| | - Masaru Yokoyama
- Pathogen Genomics Center, National Institute of Infectious Diseases, Musashi Murayama, Tokyo, Japan
| | - Yosuke Maeda
- Department of Medical Virology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Hiromi Terasawa
- Department of Medical Virology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Shinji Harada
- Department of Medical Virology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Hironori Sato
- Pathogen Genomics Center, National Institute of Infectious Diseases, Musashi Murayama, Tokyo, Japan
| | - Keisuke Yusa
- Division of Biological Chemistry and Biologicals, National Institute of Health Sciences, Setagaya, Tokyo, Japan
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16
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Activity of the HIV-1 attachment inhibitor BMS-626529, the active component of the prodrug BMS-663068, against CD4-independent viruses and HIV-1 envelopes resistant to other entry inhibitors. Antimicrob Agents Chemother 2013; 57:4172-80. [PMID: 23774428 DOI: 10.1128/aac.00513-13] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
BMS-626529 is a novel small-molecule HIV-1 attachment inhibitor active against both CCR5- and CXCR4-tropic viruses. BMS-626529 functions by preventing gp120 from binding to CD4. A prodrug of this compound, BMS-663068, is currently in clinical development. As a theoretical resistance pathway to BMS-663068 could be the development of a CD4-independent phenotype, we examined the activity of BMS-626529 against CD4-independent viruses and investigated whether resistance to BMS-626529 could be associated with a CD4-independent phenotype. Finally, we evaluated whether cross-resistance exists between BMS-626529 and other HIV-1 entry inhibitors. Two laboratory-derived envelopes with a CD4-independent phenotype (one CXCR4 tropic and one CCR5 tropic), five envelopes from clinical isolates with preexisting BMS-626529 resistance, and several site-specific mutant BMS-626529-resistant envelopes were examined for their dependence on CD4 for infectivity or susceptibility to BMS-626529. Viruses resistant to other entry inhibitors (enfuvirtide, maraviroc, and ibalizumab) were also examined for susceptibility to BMS-626529. Both CD4-independent laboratory isolates retained sensitivity to BMS-626529 in CD4(-) cells, while HIV-1 envelopes from viruses resistant to BMS-626529 exhibited no evidence of a CD4-independent phenotype. BMS-626529 also exhibited inhibitory activity against ibalizumab- and enfuvirtide-resistant envelopes. While there appeared to be some association between maraviroc resistance and reduced susceptibility to BMS-626529, an absolute correlation cannot be presumed, since some CCR5-tropic maraviroc-resistant envelopes remained sensitive to BMS-626529. Clinical use of the prodrug BMS-663068 is unlikely to promote resistance via generation of CD4-independent virus. No cross-resistance between BMS-626529 and other HIV entry inhibitors was observed, which could allow for sequential or concurrent use with different classes of entry inhibitors.
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17
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Roche M, Salimi H, Duncan R, Wilkinson BL, Chikere K, Moore MS, Webb NE, Zappi H, Sterjovski J, Flynn JK, Ellett A, Gray LR, Lee B, Jubb B, Westby M, Ramsland PA, Lewin SR, Payne RJ, Churchill MJ, Gorry PR. A common mechanism of clinical HIV-1 resistance to the CCR5 antagonist maraviroc despite divergent resistance levels and lack of common gp120 resistance mutations. Retrovirology 2013; 10:43. [PMID: 23602046 PMCID: PMC3648390 DOI: 10.1186/1742-4690-10-43] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2012] [Accepted: 04/17/2013] [Indexed: 12/02/2022] Open
Abstract
Background The CCR5 antagonist maraviroc (MVC) inhibits human immunodeficiency virus type 1 (HIV-1) entry by altering the CCR5 extracellular loops (ECL), such that the gp120 envelope glycoproteins (Env) no longer recognize CCR5. The mechanisms of HIV-1 resistance to MVC, the only CCR5 antagonist licensed for clinical use are poorly understood, with insights into MVC resistance almost exclusively limited to knowledge obtained from in vitro studies or from studies of resistance to other CCR5 antagonists. To more precisely understand mechanisms of resistance to MVC in vivo, we characterized Envs isolated from 2 subjects who experienced virologic failure on MVC. Results Envs were cloned from subjects 17 and 24 before commencement of MVC (17-Sens and 24-Sens) and after virologic failure (17-Res and 24-Res). The Envs cloned during virologic failure showed broad divergence in resistance levels, with 17-Res Env exhibiting a relatively high maximal percent inhibition (MPI) of ~90% in NP2-CD4/CCR5 cells and peripheral blood mononuclear cells (PBMC), and 24-Res Env exhibiting a very low MPI of ~0 to 12% in both cell types, indicating relatively “weak” and “strong” resistance, respectively. Resistance mutations were strain-specific and mapped to the gp120 V3 loop. Affinity profiling by the 293-Affinofile assay and mathematical modeling using VERSA (Viral Entry Receptor Sensitivity Analysis) metrics revealed that 17-Res and 24-Res Envs engaged MVC-bound CCR5 inefficiently or very efficiently, respectively. Despite highly divergent phenotypes, and a lack of common gp120 resistance mutations, both resistant Envs exhibited an almost superimposable pattern of dramatically increased reliance on sulfated tyrosine residues in the CCR5 N-terminus, and on histidine residues in the CCR5 ECLs. This altered mechanism of CCR5 engagement rendered both the resistant Envs susceptible to neutralization by a sulfated peptide fragment of the CCR5 N-terminus. Conclusions Clinical resistance to MVC may involve divergent Env phenotypes and different genetic alterations in gp120, but the molecular mechanism of resistance of the Envs studied here appears to be related. The increased reliance on sulfated CCR5 N-terminus residues suggests a new avenue to block HIV-1 entry by CCR5 N-terminus sulfopeptidomimetic drugs.
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Affiliation(s)
- Michael Roche
- Center for Virology, Monash University, Melbourne, Victoria, Australia
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18
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Abstract
The human immunodeficiency virus (HIV) enters cells through a series of molecular interactions between the HIV envelope protein and cellular receptors, thus providing many opportunities to block infection. Entry inhibitors are currently being used in the clinic, and many more are under development. Unfortunately, as is the case for other classes of antiretroviral drugs that target later steps in the viral life cycle, HIV can become resistant to entry inhibitors. In contrast to inhibitors that block viral enzymes in intracellular compartments, entry inhibitors interfere with the function of the highly variable envelope glycoprotein as it continuously adapts to changing immune pressure and available target cells in the extracellular environment. Consequently, pathways and mechanisms of resistance for entry inhibitors are varied and often involve mutations across the envelope gene. This review provides a broad overview of entry inhibitor resistance mechanisms that inform our understanding of HIV entry and the design of new inhibitors and vaccines.
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Affiliation(s)
- Christopher J De Feo
- Office of Vaccine Research and Review, Center for Biologics Evaluation and Research, US Food and Drug Administration, 8800 Rockville Pike, Bethesda, MD 20892, USA.
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19
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Haqqani AA, Tilton JC. Entry inhibitors and their use in the treatment of HIV-1 infection. Antiviral Res 2013; 98:158-70. [PMID: 23541872 DOI: 10.1016/j.antiviral.2013.03.017] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Revised: 03/18/2013] [Accepted: 03/19/2013] [Indexed: 12/20/2022]
Abstract
Entry of HIV into target cells is a complex, multi-stage process involving sequential attachment and CD4 binding, coreceptor binding, and membrane fusion. HIV entry inhibitors are a complex group of drugs with multiple mechanisms of action depending on the stage of the viral entry process they target. Two entry inhibitors are currently approved for the treatment of HIV-infected patients. Maraviroc, a CCR5 antagonist, blocks interactions between the viral envelope proteins and the CCR5 coreceptor. Enfuvirtide, a fusion inhibitor, disrupts conformational changes in gp41 that drive membrane fusion. A wide array of additional agents are in various stages of development. This review covers the entry inhibitors and their use in the treatment of HIV-infected patients.
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Affiliation(s)
- Aiman A Haqqani
- Case Center for Proteomics and Bioinformatics, Case Western Reserve University, Cleveland, OH 44106, USA
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20
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Use of G-protein-coupled and -uncoupled CCR5 receptors by CCR5 inhibitor-resistant and -sensitive human immunodeficiency virus type 1 variants. J Virol 2013; 87:6569-81. [PMID: 23468486 DOI: 10.1128/jvi.00099-13] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Small-molecule CCR5 inhibitors such as vicriviroc (VVC) and maraviroc (MVC) are allosteric modulators that impair HIV-1 entry by stabilizing a CCR5 conformation that the virus recognizes inefficiently. Viruses resistant to these compounds are able to bind the inhibitor-CCR5 complex while also interacting with the free coreceptor. CCR5 also interacts intracellularly with G proteins, as part of its signal transduction functions, and this process alters its conformation. Here we investigated whether the action of VVC against inhibitor-sensitive and -resistant viruses is affected by whether or not CCR5 is coupled to G proteins such as Gαi. Treating CD4(+) T cells with pertussis toxin to uncouple the Gαi subunit from CCR5 increased the potency of VVC against the sensitive viruses and revealed that VVC-resistant viruses use the inhibitor-bound form of Gαi-coupled CCR5 more efficiently than they use uncoupled CCR5. Supportive evidence was obtained by expressing a signaling-deficient CCR5 mutant with an impaired ability to bind to G proteins, as well as two constitutively active mutants that activate G proteins in the absence of external stimuli. The implication of these various studies is that the association of intracellular domains of CCR5 with the signaling machinery affects the conformation of the external and transmembrane domains and how they interact with small-molecule inhibitors of HIV-1 entry.
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21
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Anti-CD4 monoclonal antibody ibalizumab exhibits breadth and potency against HIV-1, with natural resistance mediated by the loss of a V5 glycan in envelope. J Acquir Immune Defic Syndr 2013; 62:1-9. [PMID: 23023102 DOI: 10.1097/qai.0b013e3182732746] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Passive immunization for the prevention of HIV-1 infection is currently being reenergized. The anti-CD4 monoclonal antibody ibalizumab has demonstrated safety and efficacy in phase 1 and 2 clinical trials for treatment of HIV-1 infection and is undergoing a phase 1 clinical trial in HIV-1 uninfected individuals for prevention. Here, we sought to assess ibalizumab antiviral breadth and potency and to identify determinants of natural preexisting resistance. METHODS Ibalizumab breadth and potency was assessed against a large clinically relevant panel of HIV-1 pseudoviruses (n = 116) commonly used to assess vaccine candidates. Determinants of resistance were assessed by sequence analysis. RESULTS Ibalizumab neutralized 92% and 66% of viruses as defined by 50% and 80% inhibition, respectively. Median in vitro neutralization potency by IC50 was 0.03 μg/mL, substantially lower than the broadly neutralizing mAbs, PG9, or VRC01. The dominant determinant of resistance was the absence of a potential N-linked glycosylation site (PNGS) at the V5 N-terminus (P < 0.001), with the V2 loop length possibly influencing the degree of resistance afforded by the absence of the V5 N-terminal PNGS (P = 0.001). Other significant independent correlates of resistance included PNGS at position 386 and the side chain length of residue 375. Ibalizumab exhibited complementary resistance to VRC01 (P = 0.006) and sCD4 (P < 0.001), in part mediated by the V5 PNGS. CONCLUSIONS Ibalizumab breadth and potency compared favorably with broadly neutralizing anti-HIV-1 monoclonal antibodies, supporting the clinical development of ibalizumab, alone or in combination, for HIV-1 prevention.
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22
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de Voux A, Chan MC, Folefoc AT, Madziva MT, Flanagan CA. Constitutively active CCR5 chemokine receptors differ in mediating HIV envelope-dependent fusion. PLoS One 2013; 8:e54532. [PMID: 23355876 PMCID: PMC3552960 DOI: 10.1371/journal.pone.0054532] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 12/12/2012] [Indexed: 11/18/2022] Open
Abstract
The CCR5 chemokine receptor is a rhodopsin-like G protein-coupled receptor that mediates the effects of pro-inflammatory β-chemokines. CCR5 is also the major co-receptor for entry of human immunodeficiency virus (HIV) into human cells. G protein-coupled receptors exist in ensembles of active and inactive conformations. Active receptor conformations can be stabilized by mutations. Although binding of the HIV envelope protein to CCR5 stimulates cellular signaling, the CCR5 conformation that induces fusion of the viral membrane with cellular membranes is not known. We mutated conserved amino acids to generate constitutively active CCR5 receptors, which are stabilized in active conformations, and tested the ability of constitutively active CCR5 receptors to mediate HIV envelope-directed membrane fusion. Mutation of the Asp3.49(125) and Arg6.32(225) residues of CCR5 did not cause constitutive activity, but Lys or Pro substitutions for Thr2.56(82), in the TxP motif, caused high basal inositol phosphate signaling. Signaling did not increase in response to MIP-1β, suggesting that the Thr2.56(82) mutants were fully stabilized in active conformations. The Thr2.56(82)Lys mutation severely decreased cell surface CCR5 expression. Combining the Thr2.56(82)Lys mutation with an Arg6.32(225)Gln mutation partially reversed the decrease in expression. Mutants with Thr2.56(82)Lys substitutions were poor mediators of HIV envelope-directed membrane fusion, but mutants with the Thr2.65(82)Pro substitution exhibited full co-receptor function. Our results suggest that the Thr2.65(82)Lys and Thr2.65(82)Pro mutations stabilize distinct constitutively active CCR5 conformations. Lys in position 2.65(82) stabilizes activated receptor conformations that appear to be constitutively internalized and do not induce envelope-dependent membrane fusion, whereas Pro stabilizes activated conformations that are not constitutively internalized and fully mediate envelope-directed membrane fusion.
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Affiliation(s)
- Alex de Voux
- Medical Research Council Receptor Biology Research Unit, Division of Medical Biochemistry, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Mei-Chi Chan
- Medical Research Council Receptor Biology Research Unit, Division of Medical Biochemistry, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Asongna T. Folefoc
- Medical Research Council Receptor Biology Research Unit, Division of Medical Biochemistry, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Michael T. Madziva
- Medical Research Council Receptor Biology Research Unit, School of Physiology, University of the Witwatersrand, Johannesburg, South Africa
| | - Colleen A. Flanagan
- Medical Research Council Receptor Biology Research Unit, School of Physiology, University of the Witwatersrand, Johannesburg, South Africa
- * E-mail:
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23
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Savkovic B, Symonds G, Murray JM. Stochastic model of in-vivo X4 emergence during HIV infection: implications for the CCR5 inhibitor maraviroc. PLoS One 2012; 7:e38755. [PMID: 22866173 PMCID: PMC3398969 DOI: 10.1371/journal.pone.0038755] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Accepted: 05/11/2012] [Indexed: 12/30/2022] Open
Abstract
The emergence of X4 tropic viral strains throughout the course of HIV infection is associated with poorer prognostic outcomes and faster progressions to AIDS than for patients in whom R5 viral strains predominate. Here we investigate a stochastic model to account for the emergence of X4 virus via mutational intermediates of lower fitness that exhibit dual/mixed (D/M) tropism, and employ the model to investigate whether the administration of CCR5 blockers in-vivo is likely to promote a shift towards X4 tropism. We show that the proposed stochastic model can account for X4 emergence with a median time of approximately 4 years post-infection as a result of: 1.) random stochastic mutations in the V3 region of env during the reverse transcription step of infection; 2.) increasing numbers of CXCR4-expressing activated naive CD4+ T cells with declining total CD4+ T cell counts, thereby providing increased numbers of activated target cells for productive infection by X4 virus. Our model indicates that administration of the CCR5 blocker maraviroc does not promote a shift towards X4 tropism, assuming sufficient efficacy of background therapy (BT). However our modelling also indicates that administration of maraviroc as a monotherapy or with BT of suboptimal efficacy can promote emergence of X4 tropic virus, resulting in accelerated progression to AIDS. Taken together, our results demonstrate that maraviroc is safe and effective if co-administered with sufficiently potent BT, but that suboptimal BT may promote X4 emergence and accelerated progression to AIDS. These results underscore the clinical importance for careful selection of BT when CCR5 blockers are administered in-vivo.
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Affiliation(s)
- Borislav Savkovic
- School of Mathematics and Statistics, University of New South Wales, Sydney, Australia.
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24
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Parrish NF, Wilen CB, Banks LB, Iyer SS, Pfaff JM, Salazar-Gonzalez JF, Salazar MG, Decker JM, Parrish EH, Berg A, Hopper J, Hora B, Kumar A, Mahlokozera T, Yuan S, Coleman C, Vermeulen M, Ding H, Ochsenbauer C, Tilton JC, Permar SR, Kappes JC, Betts MR, Busch MP, Gao F, Montefiori D, Haynes BF, Shaw GM, Hahn BH, Doms RW. Transmitted/founder and chronic subtype C HIV-1 use CD4 and CCR5 receptors with equal efficiency and are not inhibited by blocking the integrin α4β7. PLoS Pathog 2012; 8:e1002686. [PMID: 22693444 PMCID: PMC3364951 DOI: 10.1371/journal.ppat.1002686] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Accepted: 03/23/2012] [Indexed: 12/25/2022] Open
Abstract
Sexual transmission of human immunodeficiency virus type 1 (HIV-1) most often results from productive infection by a single transmitted/founder (T/F) virus, indicating a stringent mucosal bottleneck. Understanding the viral traits that overcome this bottleneck could have important implications for HIV-1 vaccine design and other prevention strategies. Most T/F viruses use CCR5 to infect target cells and some encode envelope glycoproteins (Envs) that contain fewer potential N-linked glycosylation sites and shorter V1/V2 variable loops than Envs from chronic viruses. Moreover, it has been reported that the gp120 subunits of certain transmitted Envs bind to the gut-homing integrin α4β7, possibly enhancing virus entry and cell-to-cell spread. Here we sought to determine whether subtype C T/F viruses, which are responsible for the majority of new HIV-1 infections worldwide, share biological properties that increase their transmission fitness, including preferential α4β7 engagement. Using single genome amplification, we generated panels of both T/F (n = 20) and chronic (n = 20) Env constructs as well as full-length T/F (n = 6) and chronic (n = 4) infectious molecular clones (IMCs). We found that T/F and chronic control Envs were indistinguishable in the efficiency with which they used CD4 and CCR5. Both groups of Envs also exhibited the same CD4+ T cell subset tropism and showed similar sensitivity to neutralization by CD4 binding site (CD4bs) antibodies. Finally, saturating concentrations of anti-α4β7 antibodies failed to inhibit infection and replication of T/F as well as chronic control viruses, although the growth of the tissue culture-adapted strain SF162 was modestly impaired. These results indicate that the population bottleneck associated with mucosal HIV-1 acquisition is not due to the selection of T/F viruses that use α4β7, CD4 or CCR5 more efficiently. Most new HIV-1 infections worldwide are caused by the sexual transmission of subtype C viruses, which are prevalent in Asia and southern Africa. While chronically infected individuals harbor a genetically diverse set of viruses, most new infections are established by single variants, termed transmitted/founder (T/F) viruses. This raises the question whether certain viral variants have particular properties allowing them to more efficiently overcome the transmission bottleneck. Preferential binding of the viral envelope (Env) to the integrin α4β7 has been hypothesized as one important feature of transmitted viruses. Here, we compared Envs from subtype C viruses that were transmitted to those that were prevalent in chronic infections for efficiency in utilizing α4β7, CD4 and CCR5 for cell entry and replication. We found that transmitted and chronic Envs engaged CD4 and CCR5 with equal efficiency, and that blocking the interaction between Env and α4β7 failed to inhibit replication of T/F as well as control viruses. While the search for determinants of transmission fitness remains an important goal, preferential CD4, CCR5 or α4β7 interactions do not appear to represent distinguishing features of T/F viruses.
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Affiliation(s)
- Nicholas F. Parrish
- Department of Microbiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Craig B. Wilen
- Department of Microbiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Lauren B. Banks
- Department of Microbiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Shilpa S. Iyer
- Department of Microbiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Jennifer M. Pfaff
- Department of Microbiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Jesus F. Salazar-Gonzalez
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Maria G. Salazar
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Julie M. Decker
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Erica H. Parrish
- Department of Microbiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Anna Berg
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - Jennifer Hopper
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - Bhavna Hora
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - Amit Kumar
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - Tatenda Mahlokozera
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - Sally Yuan
- Department of Microbiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Charl Coleman
- Donation Testing Department, South African National Blood Service, Roodepoort, Gauteng, South Africa
| | - Marion Vermeulen
- Donation Testing Department, South African National Blood Service, Roodepoort, Gauteng, South Africa
| | - Haitao Ding
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Christina Ochsenbauer
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - John C. Tilton
- Department of General Medical Sciences, Center for Proteomics, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Sallie R. Permar
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, North Carolina, United States of America
- Department of Pediatrics, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - John C. Kappes
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Michael R. Betts
- Department of Microbiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Michael P. Busch
- Blood Systems Research Institute, San Francisco, California, United States of America
| | - Feng Gao
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, North Carolina, United States of America
- Department of Medicine, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - David Montefiori
- Department of Surgery, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - Barton F. Haynes
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, North Carolina, United States of America
- Department of Medicine, Duke University School of Medicine, Durham, North Carolina, United States of America
- Department of Immunology, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - George M. Shaw
- Department of Microbiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Beatrice H. Hahn
- Department of Microbiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail: (BHH); (RWD)
| | - Robert W. Doms
- Department of Microbiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail: (BHH); (RWD)
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25
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Berro R, Klasse PJ, Jakobsen MR, Gorry PR, Moore JP, Sanders RW. V3 determinants of HIV-1 escape from the CCR5 inhibitors Maraviroc and Vicriviroc. Virology 2012; 427:158-65. [PMID: 22424737 DOI: 10.1016/j.virol.2012.02.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Revised: 02/01/2012] [Accepted: 02/08/2012] [Indexed: 10/28/2022]
Abstract
HIV-1 develops resistance to CCR5 antagonists such as Maraviroc (MVC) and Vicriviroc (VVC) both in vitro and in vivo, with most changes arising in the gp120 V3 region. Both compounds bind to the same hydrophobic cavity in CCR5 in subtly different ways. Here, we investigated which V3 sequence changes are most associated with MVC and VVC resistance and how they affect the interaction between gp120 and the CCR5 NT. We found that VVC- and MVC-selected amino acid changes map to different V3 locations and involve residues that interact with the CCR5 NT in different ways. Changes in VVC-selected, but not MVC-selected, variants often involve charged residues. Although the overall V3 charge tends not to change, the introduction or removal of charged residues at specific positions affects the local electrostatic potential and could have structural and functional implications. In summary, VVC and MVC trigger the evolution of distinct HIV-1 resistance patterns in V3.
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Affiliation(s)
- Reem Berro
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, NY 10065, USA
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26
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Differential use of CCR5 by HIV-1 clinical isolates resistant to small-molecule CCR5 antagonists. Antimicrob Agents Chemother 2012; 56:1931-5. [PMID: 22252820 DOI: 10.1128/aac.06061-11] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
How HIV-1 resistant to small-molecule CCR5 antagonists uses the coreceptor for entry has been studied in a limited number of isolates. We characterized dependence on the N terminus (NT) and the second extracellular loop (ECL2) of CCR5 of three vicriviroc (VCV)-resistant clinical isolates broadly cross-resistant to other CCR5 antagonists. Pseudoviruses were constructed to assess CCR5 use by VCV-sensitive and -resistant envelopes of subtype B and C viruses. We determined the extent of entry inhibition by monoclonal antibodies (MAbs) directed against the NT and ECL2 in the presence and absence of VCV and the capacity of these pseudoviruses to use CCR5 mutants that contained scanning alanine substitutions in the CCR5 NT and ECL2 domains. Sensitive and resistant viruses were completely and competitively inhibited by the ECL2-specific MAb 2D7, whereas the NT-specific MAb CTC5 led to partial noncompetitive inhibition. VCV-resistant clones showed greater sensitivity to 2D7 than VCV-sensitive clones, but in the presence of saturating VCV concentrations, the 2D7 susceptibilities of two VCV-resistant viruses were similar to that of VCV-sensitive virus. The entry of VCV-sensitive and -resistant isolates was impaired to differing degrees by alanine mutations in CCR5; substitutions in NT had the greatest effect on viral entry. HIV-1 clinical isolates broadly resistant to CCR5 antagonists demonstrated significant heterogeneity in their use of CCR5. This heterogeneity makes it difficult to draw general conclusions about the relationship between patterns of CCR5 antagonist resistance and the use of specific CCR5 domains for entry.
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27
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Wilen CB, Tilton JC, Doms RW. Molecular mechanisms of HIV entry. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 726:223-42. [PMID: 22297516 DOI: 10.1007/978-1-4614-0980-9_10] [Citation(s) in RCA: 150] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Human immunodeficiency virus (HIV) entry is a complex and intricate process that facilitates delivery of the viral genome to the host cell. The only viral surface protein, Envelope (Env), is composed of a trimer of gp120 and gp41 heterodimers. It is essentially a fusion machine cloaked in a shroud of carbohydrate structures and variable loops of amino acids that enable it to evade the humoral immune response. For entry to occur gp120 sequentially engages the host protein CD4 and then one of two chemokine coreceptors, either CCR5 or CXCR4. CD4 binding facilitates exposure and formation of the coreceptor-binding site, and coreceptor binding then triggers the membrane fusion machinery in the gp41 subunit. Our understanding of HIV entry has led to the development of successful small molecule inhibitors for the clinical treatment of HIV infection as well as insights into viral tropism and pathogenesis.
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Affiliation(s)
- Craig B Wilen
- Department of Microbiology, University of Pennsylvania, Philadelphia, PA 19104, USA
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28
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Tsibris AMN, Pal U, Schure AL, Veazey RS, Kunstman KJ, Henrich TJ, Klasse PJ, Wolinsky SM, Kuritzkes DR, Moore JP. SHIV-162P3 infection of rhesus macaques given maraviroc gel vaginally does not involve resistant viruses. PLoS One 2011; 6:e28047. [PMID: 22164225 PMCID: PMC3229503 DOI: 10.1371/journal.pone.0028047] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Accepted: 10/31/2011] [Indexed: 01/17/2023] Open
Abstract
Maraviroc (MVC) gels are effective at protecting rhesus macaques from vaginal SHIV transmission, but breakthrough infections can occur. To determine the effects of a vaginal MVC gel on infecting SHIV populations in a macaque model, we analyzed plasma samples from three rhesus macaques that received a MVC vaginal gel (day 0) but became infected after high-dose SHIV-162P3 vaginal challenge. Two infected macaques that received a placebo gel served as controls. The infecting SHIV-162P3 stock had an overall mean genetic distance of 0.294±0.027%; limited entropy changes were noted across the envelope (gp160). No envelope mutations were observed consistently in viruses isolated from infected macaques at days 14-21, the time of first detectable viremia, nor selected at later time points, days 42-70. No statistically significant differences in MVC susceptibilities were observed between the SHIV inoculum (50% inhibitory concentration [IC(50)] 1.87 nM) and virus isolated from the three MVC-treated macaques (MVC IC(50) 1.18 nM, 1.69 nM, and 1.53 nM, respectively). Highlighter plot analyses suggested that infection was established in each MVC-treated animal by one founder virus genotype. The expected Poisson distribution of pairwise Hamming Distance frequency counts was observed and a phylogenetic analysis did not identify infections with distinct lineages from the challenge stock. These data suggest that breakthrough infections most likely result from incomplete viral inhibition and not the selection of MVC-resistant variants.
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Affiliation(s)
- Athe M N Tsibris
- Massachusetts General Hospital, Boston, Massachusetts, United States of America.
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29
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Mehla R, Bivalkar-Mehla S, Chauhan A. A flavonoid, luteolin, cripples HIV-1 by abrogation of tat function. PLoS One 2011; 6:e27915. [PMID: 22140483 PMCID: PMC3227592 DOI: 10.1371/journal.pone.0027915] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Accepted: 10/27/2011] [Indexed: 12/17/2022] Open
Abstract
Despite the effectiveness of combination antiretroviral treatment (cART) against HIV-1, evidence indicates that residual infection persists in different cell types. Intensification of cART does not decrease the residual viral load or immune activation. cART restricts the synthesis of infectious virus but does not curtail HIV-1 transcription and translation from either the integrated or unintegrated viral genomes in infected cells. All treated patients with full viral suppression actually have low-level viremia. More than 60% of treated individuals also develop minor HIV-1 -associated neurocognitive deficits (HAND) due to residual virus and immune activation. Thus, new therapeutic agents are needed to curtail HIV-1 transcription and residual virus. In this study, luteolin, a dietary supplement, profoundly reduced HIV-1 infection in reporter cells and primary lymphocytes. HIV-1inhibition by luteolin was independent of viral entry, as shown by the fact that wild-type and VSV-pseudotyped HIV-1 infections were similarly inhibited. Luteolin was unable to inhibit viral reverse transcription. Luteolin had antiviral activity in a latent HIV-1 reactivation model and effectively ablated both clade-B- and -C -Tat-driven LTR transactivation in reporter assays but had no effect on Tat expression and its sub-cellular localization. We conclude that luteolin confers anti-HIV-1 activity at the Tat functional level. Given its biosafety profile and ability to cross the blood-brain barrier, luteolin may serve as a base flavonoid to develop potent anti-HIV-1 derivatives to complement cART.
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Affiliation(s)
- Rajeev Mehla
- Department of Pathology, Microbiology and Immunology, University of South Carolina School of Medicine, Columbia, South Carolina, United States of America
| | - Shalmali Bivalkar-Mehla
- Department of Pathology, Microbiology and Immunology, University of South Carolina School of Medicine, Columbia, South Carolina, United States of America
| | - Ashok Chauhan
- Department of Pathology, Microbiology and Immunology, University of South Carolina School of Medicine, Columbia, South Carolina, United States of America
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, South Carolina, United States of America
- * E-mail:
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30
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HIV-1 clinical isolates resistant to CCR5 antagonists exhibit delayed entry kinetics that are corrected in the presence of drug. J Virol 2011; 86:1119-28. [PMID: 22090117 DOI: 10.1128/jvi.06421-11] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
HIV CCR5 antagonists select for env gene mutations that enable virus entry via drug-bound coreceptor. To investigate the mechanisms responsible for viral adaptation to drug-bound coreceptor-mediated entry, we studied viral isolates from three participants who developed CCR5 antagonist resistance during treatment with vicriviroc (VCV), an investigational small-molecule CCR5 antagonist. VCV-sensitive and -resistant viruses were isolated from one HIV subtype C- and two subtype B-infected participants; VCV-resistant isolates had mutations in the V3 loop of gp120 and were cross-resistant to TAK-779, an investigational antagonist, and maraviroc (MVC). All three resistant isolates contained a 306P mutation but had variable mutations elsewhere in the V3 stem. We used a virus-cell β-lactamase (BlaM) fusion assay to determine the entry kinetics of recombinant viruses that incorporated full-length VCV-sensitive and -resistant envelopes. VCV-resistant isolates exhibited delayed entry rates in the absence of drug, relative to pretherapy VCV-sensitive isolates. The addition of drug corrected these delays. These findings were generalizable across target cell types with a range of CD4 and CCR5 surface densities and were observed when either population-derived or clonal envelopes were used to construct recombinant viruses. V3 loop mutations alone were sufficient to restore virus entry in the presence of drug, and the accumulation of V3 mutations during VCV therapy led to progressively higher rates of viral entry. We propose that the restoration of pre-CCR5 antagonist therapy HIV entry kinetics drives the selection of V3 loop mutations and may represent a common mechanism that underlies the emergence of CCR5 antagonist resistance.
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31
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Applications of next-generation sequencing technologies to diagnostic virology. Int J Mol Sci 2011; 12:7861-84. [PMID: 22174638 PMCID: PMC3233444 DOI: 10.3390/ijms12117861] [Citation(s) in RCA: 177] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 10/20/2011] [Accepted: 11/07/2011] [Indexed: 02/07/2023] Open
Abstract
Novel DNA sequencing techniques, referred to as “next-generation” sequencing (NGS), provide high speed and throughput that can produce an enormous volume of sequences with many possible applications in research and diagnostic settings. In this article, we provide an overview of the many applications of NGS in diagnostic virology. NGS techniques have been used for high-throughput whole viral genome sequencing, such as sequencing of new influenza viruses, for detection of viral genome variability and evolution within the host, such as investigation of human immunodeficiency virus and human hepatitis C virus quasispecies, and monitoring of low-abundance antiviral drug-resistance mutations. NGS techniques have been applied to metagenomics-based strategies for the detection of unexpected disease-associated viruses and for the discovery of novel human viruses, including cancer-related viruses. Finally, the human virome in healthy and disease conditions has been described by NGS-based metagenomics.
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32
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Roche M, Jakobsen MR, Ellett A, Salimiseyedabad H, Jubb B, Westby M, Lee B, Lewin SR, Churchill MJ, Gorry PR. HIV-1 predisposed to acquiring resistance to maraviroc (MVC) and other CCR5 antagonists in vitro has an inherent, low-level ability to utilize MVC-bound CCR5 for entry. Retrovirology 2011; 8:89. [PMID: 22054077 PMCID: PMC3217884 DOI: 10.1186/1742-4690-8-89] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Accepted: 11/07/2011] [Indexed: 11/19/2022] Open
Abstract
Background Maraviroc (MVC) and other CCR5 antagonists are HIV-1 entry inhibitors that bind to- and alter the conformation of CCR5, such that CCR5 is no longer recognized by the viral gp120 envelope (Env) glycoproteins. Resistance to CCR5 antagonists results from HIV-1 Env acquiring the ability to utilize the drug-bound conformation of CCR5. Selecting for HIV-1 resistance to CCR5-antagonists in vitro is relatively difficult. However, the CCR5-using CC1/85 strain appears to be uniquely predisposed to acquiring resistance to several CCR5 antagonists in vitro including MVC, vicriviroc and AD101. Findings Here, we show that Env derived from the parental CC1/85 strain is inherently capable of a low affinity interaction with MVC-bound CCR5. However, this phenotype was only revealed in 293-Affinofile cells and NP2-CD4/CCR5 cells that express very high levels of CCR5, and was masked in TZM-bl, JC53 and U87-CD4/CCR5 cells as well as PBMC, which express comparatively lower levels of CCR5 and which are more commonly used to detect resistance to CCR5 antagonists. Conclusions Env derived from the CC1/85 strain of HIV-1 is inherently capable of a low-affinity interaction with MVC-bound CCR5, which helps explain the relative ease in which CC1/85 can acquire resistance to CCR5 antagonists in vitro. The detection of similar phenotypes in patients may identify those who could be at higher risk of virological failure on MVC.
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Affiliation(s)
- Michael Roche
- Center for Virology, Burnet Institute, Melbourne, Victoria, Australia
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33
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Baatz F, Struck D, Lemaire M, De Landtsheer S, Servais JY, Arendt V, Schmit JC, Perez Bercoff D. Rescue of HIV-1 long-time archived X4 strains to escape maraviroc. Antiviral Res 2011; 92:488-92. [PMID: 22020304 DOI: 10.1016/j.antiviral.2011.10.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Revised: 10/03/2011] [Accepted: 10/04/2011] [Indexed: 10/16/2022]
Abstract
Entry of Human Immunodeficiency Virus type 1 (HIV-1) into target cells is mediated by the CD4 receptor and a coreceptor, CCR5 or CXCR4. Maraviroc interferes with HIV entry by binding the CCR5 coreceptor. Virological failure to maraviroc-containing regimens can occur through the emergence of resistance, or through tropism evolution and broadened coreceptor usage. In the latter case, the physiological relevance of minority strains is a major concern. Here we report a retrospective analysis of coreceptor-usage and evolution based on 454-ultra-deep-sequencing of plasma and Peripheral Blood Mononuclear Cell (PBMC)-derived envelope V3-loops, accounting for coreceptor usage, from a patient who failed a maraviroc-containing regimen through the emergence of X4 strains. The X4 maraviroc-escape variant resulted from recombination between a long time archived proviral sequence from 2003 (5'-portion, including the V3-loop) and the dominant R5 strains circulating in plasma at the time of maraviroc-treatment initiation (3'-portion). Phylogenetic analyses and BEAST modeling highlighted that an early diverse viral quasispecies underwent a severe bottleneck following reinitiation of HAART and repeated IL-2 cycles between 1999 and 2001, leading to the transient outgrowth and archiving of one highly homogeneous X4 population from plasma, and to the expansion in plasma of one PBMC-derived R5 strain. Under maraviroc selective pressure, the early, no longer detectable X4 strains archived in PBMC were partially rescued to provide X4-determinants to the main circulating strain.
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Affiliation(s)
- Franky Baatz
- Laboratory of Retrovirology, CRP-Santé, Luxembourg, Luxembourg.
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34
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Kishko M, Somasundaran M, Brewster F, Sullivan JL, Clapham PR, Luzuriaga K. Genotypic and functional properties of early infant HIV-1 envelopes. Retrovirology 2011; 8:67. [PMID: 21843318 PMCID: PMC3189118 DOI: 10.1186/1742-4690-8-67] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Accepted: 08/15/2011] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Understanding the properties of HIV-1 variants that are transmitted from women to their infants is crucial to improving strategies to prevent transmission. In this study, 162 full-length envelope (env) clones were generated from plasma RNA obtained from 5 HIV-1 Clade B infected mother-infant pairs. Following extensive genotypic and phylogenetic analyses, 35 representative clones were selected for functional studies. RESULTS Infant quasispecies were highly homogeneous and generally represented minor maternal variants, consistent with transmission across a selective bottleneck. Infant clones did not differ from the maternal in env length, or glycosylation. All infant variants utilized the CCR5 co-receptor, but were not macrophage tropic. Relatively high levels (IC₅₀ ≥ 100 μg/ml) of autologous maternal plasma IgG were required to neutralize maternal and infant viruses; however, all infant viruses were neutralized by pooled sera from HIV-1 infected individuals, implying that they were not inherently neutralization-resistant. All infant viruses were sensitive to the HIV-1 entry inhibitors Enfuvirtide and soluble CD4; none were resistant to Maraviroc. Sensitivity to human monoclonal antibodies 4E10, 2F5, b12 and 2G12 varied. CONCLUSIONS This study provides extensive characterization of the genotypic and functional properties of HIV-1 env shortly after transmission. We present the first detailed comparisons of the macrophage tropism of infant and maternal env variants and their sensitivity to Maraviroc, the only CCR5 antagonist approved for therapeutic use. These findings may have implications for improving approaches to prevent mother-to-child HIV-1 transmission.
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Affiliation(s)
- Michael Kishko
- Graduate School of Biomedical Sciences, University of Massachusetts Medical School, Worcester, MA, USA
| | - Mohan Somasundaran
- Department of Pediatrics, University of Massachusetts Medical School, Worcester, MA, USA
| | - Frank Brewster
- Department of Pediatrics, University of Massachusetts Medical School, Worcester, MA, USA
| | - John L Sullivan
- Department of Pediatrics, University of Massachusetts Medical School, Worcester, MA, USA
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Paul R Clapham
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Katherine Luzuriaga
- Department of Pediatrics, University of Massachusetts Medical School, Worcester, MA, USA
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA
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35
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Alternative coreceptor requirements for efficient CCR5- and CXCR4-mediated HIV-1 entry into macrophages. J Virol 2011; 85:10699-709. [PMID: 21835796 DOI: 10.1128/jvi.05510-11] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Macrophage tropism of human immunodeficiency virus type 1 (HIV-1) is distinct from coreceptor specificity of the viral envelope glycoproteins (Env), but the virus-cell interactions that contribute to efficient HIV-1 entry into macrophages, particularly via CXCR4, are not well understood. Here, we characterized a panel of HIV-1 Envs that use CCR5 (n = 14) or CXCR4 (n = 6) to enter monocyte-derived macrophages (MDM) with various degrees of efficiency. Our results show that efficient CCR5-mediated MDM entry by Env-pseudotyped reporter viruses is associated with increased tolerance of several mutations within the CCR5 N terminus. In contrast, efficient CXCR4-mediated MDM entry was associated with reduced tolerance of a large deletion within the CXCR4 N terminus. Env sequence analysis and structural modeling identified amino acid variants at positions 261 and 263 within the gp41-interactive region of gp120 and a variant at position 326 within the gp120 V3 loop that were associated with efficient CXCR4-mediated MDM entry. Mutagenesis studies showed that the gp41 interaction domain variants exert a significant but strain-specific influence on CXCR4-mediated MDM entry, suggesting that the structural integrity of the gp120-gp41 interface is important for efficient CXCR4-mediated MDM entry of certain HIV-1 strains. However, the presence of Ile326 in the gp120 V3 loop stem, which we show by molecular modeling is located at the gp120-coreceptor interface and predicted to interact with the CXCR4 N terminus, was found to be critical for efficient CXCR4-mediated MDM entry of divergent CXCR4-using Envs. Together, the results of our study provide novel insights into alternative mechanisms of Env-coreceptor engagement that are associated with efficient CCR5- and CXCR4-mediated HIV-1 entry into macrophages.
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36
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Multiple CCR5 conformations on the cell surface are used differentially by human immunodeficiency viruses resistant or sensitive to CCR5 inhibitors. J Virol 2011; 85:8227-40. [PMID: 21680525 DOI: 10.1128/jvi.00767-11] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Resistance to small-molecule CCR5 inhibitors arises when HIV-1 variants acquire the ability to use inhibitor-bound CCR5 while still recognizing free CCR5. Two isolates, CC101.19 and D1/85.16, became resistant via four substitutions in the gp120 V3 region and three in the gp41 fusion peptide (FP), respectively. The binding characteristics of a panel of monoclonal antibodies (MAbs) imply that several antigenic forms of CCR5 are expressed at different levels on the surfaces of U87-CD4-CCR5 cells and primary CD4(+) T cells, in a cell-type-dependent manner. CCR5 binding and HIV-1 infection inhibition experiments suggest that the two CCR5 inhibitor-resistant viruses altered their interactions with CCR5 in different ways. As a result, both mutants became generally more sensitive to inhibition by CCR5 MAbs, and the FP mutant is specifically sensitive to a MAb that stains discrete cell surface clusters of CCR5 that may correspond to lipid rafts. We conclude that some MAbs detect different antigenic forms of CCR5 and that inhibitor-sensitive and -resistant viruses can use these CCR5 forms differently for entry in the presence or absence of CCR5 inhibitors.
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37
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Wilen CB, Wang J, Tilton JC, Miller JC, Kim KA, Rebar EJ, Sherrill-Mix SA, Patro SC, Secreto AJ, Jordan APO, Lee G, Kahn J, Aye PP, Bunnell BA, Lackner AA, Hoxie JA, Danet-Desnoyers GA, Bushman FD, Riley JL, Gregory PD, June CH, Holmes MC, Doms RW. Engineering HIV-resistant human CD4+ T cells with CXCR4-specific zinc-finger nucleases. PLoS Pathog 2011; 7:e1002020. [PMID: 21533216 PMCID: PMC3077364 DOI: 10.1371/journal.ppat.1002020] [Citation(s) in RCA: 125] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2010] [Accepted: 02/18/2011] [Indexed: 11/18/2022] Open
Abstract
HIV-1 entry requires the cell surface expression of CD4 and either the CCR5 or CXCR4 coreceptors on host cells. Individuals homozygous for the ccr5Δ32 polymorphism do not express CCR5 and are protected from infection by CCR5-tropic (R5) virus strains. As an approach to inactivating CCR5, we introduced CCR5-specific zinc-finger nucleases into human CD4+ T cells prior to adoptive transfer, but the need to protect cells from virus strains that use CXCR4 (X4) in place of or in addition to CCR5 (R5X4) remains. Here we describe engineering a pair of zinc finger nucleases that, when introduced into human T cells, efficiently disrupt cxcr4 by cleavage and error-prone non-homologous DNA end-joining. The resulting cells proliferated normally and were resistant to infection by X4-tropic HIV-1 strains. CXCR4 could also be inactivated in ccr5Δ32 CD4+ T cells, and we show that such cells were resistant to all strains of HIV-1 tested. Loss of CXCR4 also provided protection from X4 HIV-1 in a humanized mouse model, though this protection was lost over time due to the emergence of R5-tropic viral mutants. These data suggest that CXCR4-specific ZFNs may prove useful in establishing resistance to CXCR4-tropic HIV for autologous transplant in HIV-infected individuals.
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Affiliation(s)
- Craig B. Wilen
- Department of Microbiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Jianbin Wang
- Sangamo BioSciences, Richmond, California, United States of America
| | - John C. Tilton
- Department of Microbiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | | | - Kenneth A. Kim
- Sangamo BioSciences, Richmond, California, United States of America
| | - Edward J. Rebar
- Sangamo BioSciences, Richmond, California, United States of America
| | - Scott A. Sherrill-Mix
- Department of Microbiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Sean C. Patro
- Department of Microbiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Anthony J. Secreto
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Andrea P. O. Jordan
- Department of Microbiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Gary Lee
- Sangamo BioSciences, Richmond, California, United States of America
| | - Joshua Kahn
- Sangamo BioSciences, Richmond, California, United States of America
| | - Pyone P. Aye
- Divisions of Regenerative Medicine and Comparative Pathology, Tulane National Primate Research Center, Tulane University School of Medicine, Covington, Louisiana, United States of America
| | - Bruce A. Bunnell
- Divisions of Regenerative Medicine and Comparative Pathology, Tulane National Primate Research Center, Tulane University School of Medicine, Covington, Louisiana, United States of America
| | - Andrew A. Lackner
- Divisions of Regenerative Medicine and Comparative Pathology, Tulane National Primate Research Center, Tulane University School of Medicine, Covington, Louisiana, United States of America
| | - James A. Hoxie
- Department of Microbiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Gwenn A. Danet-Desnoyers
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Frederic D. Bushman
- Department of Microbiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - James L. Riley
- Abramson Family Cancer Research Institute, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | | | - Carl H. June
- Abramson Family Cancer Research Institute, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | | | - Robert W. Doms
- Department of Microbiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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Weinberger AD, Perelson AS. Persistence and emergence of X4 virus in HIV infection. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2011; 8:605-626. [PMID: 21631149 PMCID: PMC3118547 DOI: 10.3934/mbe.2011.8.605] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Approximately 50% of late-stage HIV patients develop CXCR4-tropic (X4) virus in addition to CCR5-tropic (R5) virus. X4 emergence occurs with a sharp decline in CD4+ T cell counts and accelerated time to AIDS. Why this phenotypic switch to X4 occurs is not well understood. Previously, we used numerical simulations of a mathematical model to show that across much of parameter space a promising new class of antiretroviral treatments, CCR5 inhibitors, can accelerate X4 emergence and immunodeficiency. Here, we show that mathematical model to be a minimal activation-based HIV model that produces a spontaneous switch to X4 virus at a clinically-representative time point, while also matching in vivo data showing X4 and R5 coexisting and competing to infect memory CD4+ T cells. Our analysis shows that X4 avoids competitive exclusion from an initially fitter R5 virus due to X4v unique ability to productively infect nave CD4+ T cells. We further justify the generalized conditions under which this minimal model holds, implying that a phenotypic switch can even occur when the fraction of activated nave CD4+ T cells increases at a slower rate than the fraction of activated memory CD4+ T cells. We find that it is the ratio of the fractions of activated nave and memory CD4+ T cells that must increase above a threshold to produce a switch. This occurs as the concentration of CD4+ T cells drops beneath a threshold. Thus, highly active antiretroviral therapy (HAART), which increases CD4+ T cell counts and decreases cellular activation levels, inhibits X4 viral growth. However, we show here that even in the simplest dual-strain framework, competition between R5 and X4 viruses often results in accelerated X4 emergence in response to CCR5 inhibition, further highlighting the potential danger of anti-CCR5 monotherapy in multi-strain HIV infection.
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Affiliation(s)
- Ariel D Weinberger
- Graduate Group in Biophysics, University of California, Berkeley, Berkeley, CA 94720, United States.
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Ferain T, Hoveyda H, Ooms F, Schols D, Bernard J, Fraser G. Agonist-Induced Internalization of CC Chemokine Receptor 5 as a Mechanism to Inhibit HIV Replication. J Pharmacol Exp Ther 2011; 337:655-62. [DOI: 10.1124/jpet.111.179622] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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HIV-1 escape from the CCR5 antagonist maraviroc associated with an altered and less-efficient mechanism of gp120-CCR5 engagement that attenuates macrophage tropism. J Virol 2011; 85:4330-42. [PMID: 21345957 DOI: 10.1128/jvi.00106-11] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Maraviroc (MVC) inhibits the entry of human immunodeficiency virus type 1 (HIV-1) by binding to and modifying the conformation of the CCR5 extracellular loops (ECLs). Resistance to MVC results from alterations in the HIV-1 gp120 envelope glycoproteins (Env) enabling recognition of the drug-bound conformation of CCR5. To better understand the mechanisms underlying MVC resistance, we characterized the virus-cell interactions of gp120 from in vitro-generated MVC-resistant HIV-1 (MVC-Res Env), comparing them with those of gp120 from the sensitive parental virus (MVC-Sens Env). In the absence of the drug, MVC-Res Env maintains a highly efficient interaction with CCR5, similar to that of MVC-Sens Env, and displays a relatively modest increase in dependence on the CCR5 N terminus. However, in the presence of the drug, MVC-Res Env interacts much less efficiently with CCR5 and becomes critically dependent on the CCR5 N terminus and on positively charged elements of the drug-modified CCR5 ECL1 and ECL2 regions (His88 and His181, respectively). Structural analysis suggests that the Val323 resistance mutation in the gp120 V3 loop alters the secondary structure of the V3 loop and the buried surface area of the V3 loop-CCR5 N terminus interface. This altered mechanism of gp120-CCR5 engagement dramatically attenuates the entry of HIV-1 into monocyte-derived macrophages (MDM), cell-cell fusion activity in MDM, and viral replication capacity in MDM. In addition to confirming that HIV-1 escapes MVC by becoming heavily dependent on the CCR5 N terminus, our results reveal novel interactions with the drug-modified ECLs that are critical for the utilization of CCR5 by MVC-Res Env and provide additional insights into virus-cell interactions that modulate macrophage tropism.
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Loss of asparagine-linked glycosylation sites in variable region 5 of human immunodeficiency virus type 1 envelope is associated with resistance to CD4 antibody ibalizumab. J Virol 2011; 85:3872-80. [PMID: 21289125 DOI: 10.1128/jvi.02237-10] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Ibalizumab (formerly TNX-355) is a first-in-class, monoclonal antibody inhibitor of CD4-mediated human immunodeficiency type 1 (HIV-1) entry. Multiple clinical trials with HIV-infected patients have demonstrated the antiviral activity, safety, and tolerability of ibalizumab treatment. A 9-week phase Ib study adding ibalizumab monotherapy to failing drug regimens led to transient reductions in HIV viral loads and the evolution of HIV-1 variants with reduced susceptibility to ibalizumab. This report characterizes these variants by comparing the phenotypic susceptibilities and envelope (env) sequences of (i) paired baseline and on-treatment virus populations, (ii) individual env clones from selected paired samples, and (iii) env clones containing site-directed mutations. Viruses with reduced susceptibility to ibalizumab were found to exhibit reduced susceptibility to the anti-CD4 antibody RPA-T4. Conversely, susceptibility to soluble CD4, which targets the HIV-1 gp120 envelope protein, was enhanced. No changes in susceptibility to the fusion inhibitor enfuvirtide or the CCR5 antagonist maraviroc were observed. Functionally, viruses with reduced ibalizumab susceptibility also displayed high levels of infectivity relative to those of paired baseline viruses. Individual env clones exhibiting reduced ibalizumab susceptibility contained multiple amino acid changes in different regions relative to the paired baseline clones. In particular, clones with reduced susceptibility to ibalizumab contained fewer potential asparagine-linked glycosylation sites (PNGSs) in variable region 5 (V5) than did paired ibalizumab-susceptible clones. The reduction in ibalizumab susceptibility due to the loss of V5 PNGSs was confirmed by site-directed mutagenesis. Taken together, these findings provide important insights into resistance to this new class of antiretroviral drug.
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Gavrilyuk J, Uehara H, Otsubo N, Hessell A, Burton DR, Barbas CF. Potent inhibition of HIV-1 entry with a chemically programmed antibody aided by an efficient organocatalytic synthesis. Chembiochem 2011; 11:2113-8. [PMID: 20845359 DOI: 10.1002/cbic.201000432] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Julia Gavrilyuk
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, USA
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Lorenzen T. Profile of maraviroc: a CCR5 antagonist in the management of treatment-experienced HIV patients. HIV AIDS-RESEARCH AND PALLIATIVE CARE 2010; 2:151-6. [PMID: 22096393 PMCID: PMC3218686 DOI: 10.2147/hiv.s4787] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Maraviroc is the first and, so far, the only licensed representative of the class of chemokine receptor type 5 (CCR5) inhibitors used for the treatment of human immunodeficiency virus (HIV) infection. Its safety and efficacy were demonstrated in several clinical trials, and its use was approved in 2007 by the responsible authorities. Some specific issues are correlated with maraviroc and its use. It is the only drug in the antiretroviral armamentarium, which does not interact with the viral enzymes but with a human receptor. Hence, it is able to be long-term effective only if the infecting virus uses, exclusively, the CCR5 receptor. Occurrence and detection of the CCR5 tropism are some of the great challenges of maraviroc use in treatment-experienced patients. Although up to 80% of naive patients harbor CCR5-tropic virus, the occurrence of CXCR4 or other tropisms increases with the duration of HIV infection and treatment. Nonetheless, maraviroc is a potent medication for eligible patients and helps to improve the outcome of antiretroviral treatment (ART) of HIV infection.
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Affiliation(s)
- Thore Lorenzen
- IFI Institute for Interdisciplinary Medicine, Hamburg, Germany
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A maraviroc-resistant HIV-1 with narrow cross-resistance to other CCR5 antagonists depends on both N-terminal and extracellular loop domains of drug-bound CCR5. J Virol 2010; 84:10863-76. [PMID: 20702642 DOI: 10.1128/jvi.01109-10] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
CCR5 antagonists inhibit HIV entry by binding to a coreceptor and inducing changes in the extracellular loops (ECLs) of CCR5. In this study, we analyzed viruses from 11 treatment-experienced patients who experienced virologic failure on treatment regimens containing the CCR5 antagonist maraviroc (MVC). Viruses from one patient developed high-level resistance to MVC during the course of treatment. Although resistance to one CCR5 antagonist is often associated with broad cross-resistance to other agents, these viruses remained sensitive to most other CCR5 antagonists, including vicriviroc and aplaviroc. MVC resistance was dependent upon mutations within the V3 loop of the viral envelope (Env) protein and was modulated by additional mutations in the V4 loop. Deep sequencing of pretreatment plasma viral RNA indicated that resistance appears to have occurred by evolution of drug-bound CCR5 use, despite the presence of viral sequences predictive of CXCR4 use. Envs obtained from this patient before and during MVC treatment were able to infect cells expressing very low CCR5 levels, indicating highly efficient use of a coreceptor. In contrast to previous reports in which CCR5 antagonist-resistant viruses interact predominantly with the N terminus of CCR5, these MVC-resistant Envs were also dependent upon the drug-modified ECLs of CCR5 for entry. Our results suggest a model of CCR5 cross-resistance whereby viruses that predominantly utilize the N terminus are broadly cross-resistant to multiple CCR5 antagonists, whereas viruses that require both the N terminus and antagonist-specific ECL changes demonstrate a narrow cross-resistance profile.
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Distinct molecular pathways to X4 tropism for a V3-truncated human immunodeficiency virus type 1 lead to differential coreceptor interactions and sensitivity to a CXCR4 antagonist. J Virol 2010; 84:8777-89. [PMID: 20573813 DOI: 10.1128/jvi.00333-10] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
During the course of infection, transmitted HIV-1 isolates that initially use CCR5 can acquire the ability to use CXCR4, which is associated with an accelerated progression to AIDS. Although this coreceptor switch is often associated with mutations in the stem of the viral envelope (Env) V3 loop, domains outside V3 can also play a role, and the underlying mechanisms and structural basis for how X4 tropism is acquired remain unknown. In this study we used a V3 truncated R5-tropic Env as a starting point to derive two X4-tropic Envs, termed DeltaV3-X4A.c5 and DeltaV3-X4B.c7, which took distinct molecular pathways for this change. The DeltaV3-X4A.c5 Env clone acquired a 7-amino-acid insertion in V3 that included three positively charged residues, reestablishing an interaction with the CXCR4 extracellular loops (ECLs) and rendering it highly susceptible to the CXCR4 antagonist AMD3100. In contrast, the DeltaV3-X4B.c7 Env maintained the V3 truncation but acquired mutations outside V3 that were critical for X4 tropism. In contrast to DeltaV3-X4A.c5, DeltaV3-X4B.c7 showed increased dependence on the CXCR4 N terminus (NT) and was completely resistant to AMD3100. These results indicate that HIV-1 X4 coreceptor switching can involve (i) V3 loop mutations that establish interactions with the CXCR4 ECLs, and/or (ii) mutations outside V3 that enhance interactions with the CXCR4 NT. The cooperative contributions of CXCR4 NT and ECL interactions with gp120 in acquiring X4 tropism likely impart flexibility on pathways for viral evolution and suggest novel approaches to isolate these interactions for drug discovery.
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HIV-1 resistance to CCR5 antagonists associated with highly efficient use of CCR5 and altered tropism on primary CD4+ T cells. J Virol 2010; 84:6505-14. [PMID: 20410277 DOI: 10.1128/jvi.00374-10] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We previously reported on a panel of HIV-1 clade B envelope (Env) proteins isolated from a patient treated with the CCR5 antagonist aplaviroc (APL) that were drug resistant. These Envs used the APL-bound conformation of CCR5, were cross resistant to other small-molecule CCR5 antagonists, and were isolated from the patient's pretreatment viral quasispecies as well as after therapy. We analyzed viral and host determinants of resistance and their effects on viral tropism on primary CD4(+) T cells. The V3 loop contained residues essential for viral resistance to APL, while additional mutations in gp120 and gp41 modulated the magnitude of drug resistance. However, these mutations were context dependent, being unable to confer resistance when introduced into a heterologous virus. The resistant virus displayed altered binding between gp120 and CCR5 such that the virus became critically dependent on the N' terminus of CCR5 in the presence of APL. In addition, the drug-resistant Envs studied here utilized CCR5 very efficiently: robust virus infection occurred even when very low levels of CCR5 were expressed. However, recognition of drug-bound CCR5 was less efficient, resulting in a tropism shift toward effector memory cells upon infection of primary CD4(+) T cells in the presence of APL, with relative sparing of the central memory CD4(+) T cell subset. If such a tropism shift proves to be a common feature of CCR5-antagonist-resistant viruses, then continued use of CCR5 antagonists even in the face of virologic failure could provide a relative degree of protection to the T(CM) subset of CD4(+) T cells and result in improved T cell homeostasis and immune function.
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