1
|
CCR5 Revisited: How Mechanisms of HIV Entry Govern AIDS Pathogenesis. J Mol Biol 2018; 430:2557-2589. [PMID: 29932942 DOI: 10.1016/j.jmb.2018.06.027] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 06/10/2018] [Accepted: 06/13/2018] [Indexed: 01/01/2023]
Abstract
The chemokine receptor CCR5 has been the focus of intensive studies since its role as a coreceptor for HIV entry was discovered in 1996. These studies lead to the development of small molecular drugs targeting CCR5, with maraviroc becoming in 2007 the first clinically approved chemokine receptor inhibitor. More recently, the apparent HIV cure in a patient transplanted with hematopoietic stem cells devoid of functional CCR5 rekindled the interest for inactivating CCR5 through gene therapy and pharmacological approaches. Fundamental research on CCR5 has also been boosted by key advances in the field of G-protein coupled receptor research, with the realization that CCR5 adopts a variety of conformations, and that only a subset of these conformations may be targeted by chemokine ligands. In addition, recent genetic and pathogenesis studies have emphasized the central role of CCR5 expression levels in determining the risk of HIV and SIV acquisition and disease progression. In this article, we propose to review the key properties of CCR5 that account for its central role in HIV pathogenesis, with a focus on mechanisms that regulate CCR5 expression, conformation, and interaction with HIV envelope glycoproteins.
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Fox JM, Kasprowicz R, Hartley O, Signoret N. CCR5 susceptibility to ligand-mediated down-modulation differs between human T lymphocytes and myeloid cells. J Leukoc Biol 2015; 98:59-71. [PMID: 25957306 PMCID: PMC4560160 DOI: 10.1189/jlb.2a0414-193rr] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 04/03/2015] [Indexed: 01/04/2023] Open
Abstract
CCR5 is a chemokine receptor expressed on leukocytes and a coreceptor used by HIV-1 to enter CD4(+) T lymphocytes and macrophages. Stimulation of CCR5 by chemokines triggers internalization of chemokine-bound CCR5 molecules in a process called down-modulation, which contributes to the anti-HIV activity of chemokines. Recent studies have shown that CCR5 conformational heterogeneity influences chemokine-CCR5 interactions and HIV-1 entry in transfected cells or activated CD4(+) T lymphocytes. However, the effect of CCR5 conformations on other cell types and on the process of down-modulation remains unclear. We used mAbs, some already shown to detect distinct CCR5 conformations, to compare the behavior of CCR5 on in vitro generated human T cell blasts, monocytes and MDMs and CHO-CCR5 transfectants. All human cells express distinct antigenic forms of CCR5 not detected on CHO-CCR5 cells. The recognizable populations of CCR5 receptors exhibit different patterns of down-modulation on T lymphocytes compared with myeloid cells. On T cell blasts, CCR5 is recognized by all antibodies and undergoes rapid chemokine-mediated internalization, whereas on monocytes and MDMs, a pool of CCR5 molecules is recognized by a subset of antibodies and is not removed from the cell surface. We demonstrate that this cell surface-retained form of CCR5 responds to prolonged treatment with more-potent chemokine analogs and acts as an HIV-1 coreceptor. Our findings indicate that the regulation of CCR5 is highly specific to cell type and provide a potential explanation for the observation that native chemokines are less-effective HIV-entry inhibitors on macrophages compared with T lymphocytes.
Collapse
Affiliation(s)
- James M Fox
- *Department of Biology and Hull York Medical School, Center for Immunology and Infection, University of York, York, United Kingdom; and Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | - Richard Kasprowicz
- *Department of Biology and Hull York Medical School, Center for Immunology and Infection, University of York, York, United Kingdom; and Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | - Oliver Hartley
- *Department of Biology and Hull York Medical School, Center for Immunology and Infection, University of York, York, United Kingdom; and Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | - Nathalie Signoret
- *Department of Biology and Hull York Medical School, Center for Immunology and Infection, University of York, York, United Kingdom; and Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| |
Collapse
|
4
|
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.
Collapse
Affiliation(s)
- Michael Roche
- Center for Virology, Monash University, Melbourne, Victoria, Australia
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
5
|
The magnitude of HIV-1 resistance to the CCR5 antagonist maraviroc may impart a differential alteration in HIV-1 tropism for macrophages and T-cell subsets. Virology 2013; 442:51-8. [PMID: 23602007 DOI: 10.1016/j.virol.2013.03.026] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2012] [Revised: 01/31/2013] [Accepted: 03/26/2013] [Indexed: 11/24/2022]
Abstract
Human immunodeficiency virus type 1 (HIV-1) resistance to CCR5 antagonists, including maraviroc (MVC), results from alterations in the HIV-1 envelope glycoproteins (Env) enabling recognition of antagonist-bound CCR5. Here, we characterized tropism alterations for CD4+ T-cell subsets and macrophages by Envs from two subjects who developed MVC resistance in vivo, which displayed either relatively efficient or inefficient recognition of MVC-bound CCR5. We show that MVC-resistant Env with efficient recognition of drug-bound CCR5 displays a tropism shift for CD4+ T-cell subsets associated with increased infection of central memory T-cells and reduced infection of effector memory and transitional memory T-cells, and no change in macrophage infectivity. In contrast, MVC-resistant Env with inefficient recognition of drug-bound CCR5 displays no change in tropism for CD4+ T-cell subsets, but exhibits a significant reduction in macrophage infectivity. The pattern of HIV-1 tropism alterations for susceptible cells may therefore be variable in subjects with MVC resistance.
Collapse
|
6
|
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.
Collapse
Affiliation(s)
- Aiman A Haqqani
- Case Center for Proteomics and Bioinformatics, Case Western Reserve University, Cleveland, OH 44106, USA
| | | |
Collapse
|
7
|
Vicriviroc resistance decay and relative replicative fitness in HIV-1 clinical isolates under sequential drug selection pressures. J Virol 2012; 86:6416-26. [PMID: 22491471 DOI: 10.1128/jvi.00286-12] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
We previously described an HIV-1-infected individual who developed resistance to vicriviroc (VCV), an investigational CCR5 antagonist, during 28 weeks of therapy (Tsibris AM et al., J. Virol. 82:8210-8214, 2008). To investigate the decay of VCV resistance mutations, a standard clonal analysis of full-length env (gp160) was performed on plasma HIV-1 samples obtained at week 28 (the time of VCV discontinuation) and at three subsequent time points (weeks 30, 42, and 48). During 132 days, VCV-resistant HIV-1 was replaced by VCV-sensitive viruses whose V3 loop sequences differed from the dominant pretreatment forms. A deep-sequencing analysis showed that the week 48 VCV-sensitive V3 loop form emerged from a preexisting viral variant. Enfuvirtide was added to the antiretroviral regimen at week 30; by week 48, enfuvirtide treatment selected for either the G36D or N43D HR-1 mutation. Growth competition experiments demonstrated that viruses incorporating the dominant week 28 VCV-resistant env were less fit than week 0 viruses in the absence of VCV but more fit than week 48 viruses. This week 48 fitness deficit persisted when G36D was corrected by either site-directed mutagenesis or week 48 gp41 domain swapping. The correction of N43D, in contrast, restored fitness relative to that of week 28, but not week 0, viruses. Virus entry kinetics correlated with observed fitness differences; the slower entry of enfuvirtide-resistant viruses corrected to wild-type rates in the presence of enfuvirtide. These findings suggest that while VCV and enfuvirtide select for resistance mutations in only one env subunit, gp120 and gp41 coevolve to maximize viral fitness under sequential drug selection pressures.
Collapse
|