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Webb NE, Sevareid CM, Sanchez C, Tobin NH, Aldrovandi GM. Natural Variation in HIV-1 Entry Kinetics Map to Specific Residues and Reveal an Interdependence Between Attachment and Fusion. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.25.600587. [PMID: 38979136 PMCID: PMC11230229 DOI: 10.1101/2024.06.25.600587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
HIV-1 entry kinetics reflect the fluid motion of the HIV envelope glycoprotein through at least three major structural configurations that drive virus-cell membrane fusion. The lifetime of each state is an important component of potency for inhibitors that target them. We used the time-of-addition inhibitor assay and a novel analytical strategy to define the kinetics of pre-hairpin exposure (using T20) and co-receptor engagement (via. maraviroc), through a characteristic delay metric, across a variety of naturally occurring HIV Env isolates. Among 257 distinct HIV-1 envelope isolates we found a remarkable breadth of T20 and maraviroc delays ranging from as early as 30 seconds to as late as 60 minutes. The most extreme delays were observed among transmission-linked clade C isolates. We identified four single-residue determinants of late T20 and maraviroc delays that are associated with either receptor engagement or gp41 function. Comparison of these delays with T20 sensitivity suggest co-receptor engagement and fusogenic activity in gp41 act cooperatively but sequentially to drive entry. Our findings support current models of entry where co-receptor engagement drives gp41 eclipse and have strong implications for the design of entry inhibitors and antibodies that target transient entry states. Author Summary The first step of HIV-1 infection is entry, where virus-cell membrane fusion is driven by the HIV-1 envelope glycoprotein through a series of conformational changes. Some of the most broadly active entry inhibitors work by binding conformations that exist only transiently during entry. The lifetimes of these states and the kinetics of entry are important elements of inhibitor activity for which little is known. We demonstrate a remarkable range of kinetics among 257 diverse HIV-1 isolates and find that this phenotype is highly flexible, with multiple single-residue determinants. Examination of the kinetics of two conformational landmarks shed light on novel kinetic features that offer new details about the role of co-receptor engagement and provide a framework to explain entry inhibitor synergy.
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Ramirez-Mata AS, Ostrov D, Salemi M, Marini S, Magalis BR. Machine Learning Prediction and Phyloanatomic Modeling of Viral Neuroadaptive Signatures in the Macaque Model of HIV-Mediated Neuropathology. Microbiol Spectr 2023; 11:e0308622. [PMID: 36847516 PMCID: PMC10100676 DOI: 10.1128/spectrum.03086-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 02/06/2023] [Indexed: 03/01/2023] Open
Abstract
In human immunodeficiency virus (HIV) infection, virus replication in and adaptation to the central nervous system (CNS) can result in neurocognitive deficits in approximately 25% of patients with unsuppressed viremia. While no single viral mutation can be agreed upon as distinguishing the neuroadapted population, earlier studies have demonstrated that a machine learning (ML) approach could be applied to identify a collection of mutational signatures within the virus envelope glycoprotein (Gp120) predictive of disease. The S[imian]IV-infected macaque is a widely used animal model of HIV neuropathology, allowing in-depth tissue sampling infeasible for human patients. Yet, translational impact of the ML approach within the context of the macaque model has not been tested, much less the capacity for early prediction in other, noninvasive tissues. We applied the previously described ML approach to prediction of SIV-mediated encephalitis (SIVE) using gp120 sequences obtained from the CNS of animals with and without SIVE with 97% accuracy. The presence of SIVE signatures at earlier time points of infection in non-CNS tissues indicated these signatures cannot be used in a clinical setting; however, combined with protein structural mapping and statistical phylogenetic inference, results revealed common denominators associated with these signatures, including 2-acetamido-2-deoxy-beta-d-glucopyranose structural interactions and high rate of alveolar macrophage (AM) infection. AMs were also determined to be the phyloanatomic source of cranial virus in SIVE animals, but not in animals that did not develop SIVE, implicating a role for these cells in the evolution of the signatures identified as predictive of both HIV and SIV neuropathology. IMPORTANCE HIV-associated neurocognitive disorders remain prevalent among persons living with HIV (PLWH) owing to our limited understanding of the contributing viral mechanisms and ability to predict disease onset. We have expanded on a machine learning method previously used on HIV genetic sequence data to predict neurocognitive impairment in PLWH to the more extensively sampled SIV-infected macaque model in order to (i) determine the translatability of the animal model and (ii) more accurately characterize the predictive capacity of the method. We identified eight amino acid and/or biochemical signatures in the SIV envelope glycoprotein, the most predominant of which demonstrated the potential for aminoglycan interaction characteristic of previously identified HIV signatures. These signatures were not isolated to specific points in time or to the central nervous system, limiting their use as an accurate clinical predictor of neuropathogenesis; however, statistical phylogenetic and signature pattern analyses implicate the lungs as a key player in the emergence of neuroadapted viruses.
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Affiliation(s)
- Andrea S. Ramirez-Mata
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USA
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, Florida, USA
| | - David Ostrov
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, Florida, USA
| | - Marco Salemi
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USA
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, Florida, USA
| | - Simone Marini
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USA
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, Florida, USA
- Department of Epidemiology, University of Florida, Gainesville, Florida, USA
| | - Brittany Rife Magalis
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USA
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, Florida, USA
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3
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Han M, Woottum M, Mascarau R, Vahlas Z, Verollet C, Benichou S. Mechanisms of HIV-1 cell-to-cell transfer to myeloid cells. J Leukoc Biol 2022; 112:1261-1271. [PMID: 35355323 DOI: 10.1002/jlb.4mr0322-737r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 03/09/2022] [Indexed: 12/24/2022] Open
Abstract
In addition to CD4+ T lymphocytes, cells of the myeloid lineage such as macrophages, dendritic cells (DCs), and osteoclasts (OCs) are emerging as important target cells for HIV-1, as they likely participate in all steps of pathogenesis, including sexual transmission and early virus dissemination in both lymphoid and nonlymphoid tissues where they can constitute persistent virus reservoirs. At least in vitro, these myeloid cells are poorly infected by cell-free viral particles. In contrast, intercellular virus transmission through direct cell-to-cell contacts may be a predominant mode of virus propagation in vivo leading to productive infection of these myeloid target cells. HIV-1 cell-to-cell transfer between CD4+ T cells mainly through the formation of the virologic synapse, or from infected macrophages or dendritic cells to CD4+ T cell targets, have been extensively described in vitro. Recent reports demonstrate that myeloid cells can be also productively infected through virus homotypic or heterotypic cell-to-cell transfer between macrophages or from virus-donor-infected CD4+ T cells, respectively. These modes of infection of myeloid target cells lead to very efficient spreading in these poorly susceptible cell types. Thus, the goal of this review is to give an overview of the different mechanisms reported in the literature for cell-to-cell transfer and spreading of HIV-1 in myeloid cells.
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Affiliation(s)
- Mingyu Han
- Institut Cochin, Inserm U1016, Paris, France.,Centre National de la Recherche Scientifique CNRS UMR8104, Paris, France.,Faculty of Health, University of Paris Cité, Paris, France
| | - Marie Woottum
- Institut Cochin, Inserm U1016, Paris, France.,Centre National de la Recherche Scientifique CNRS UMR8104, Paris, France.,Faculty of Health, University of Paris Cité, Paris, France
| | - Rémi Mascarau
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, Toulouse, France.,International Research Project (IRP) CNRS, Toulouse, France.,International Research Project (IRP), CNRS, Buenos Aires, Argentina
| | - Zoï Vahlas
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, Toulouse, France.,International Research Project (IRP) CNRS, Toulouse, France.,International Research Project (IRP), CNRS, Buenos Aires, Argentina
| | - Christel Verollet
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, Toulouse, France.,International Research Project (IRP) CNRS, Toulouse, France.,International Research Project (IRP), CNRS, Buenos Aires, Argentina
| | - Serge Benichou
- Institut Cochin, Inserm U1016, Paris, France.,Centre National de la Recherche Scientifique CNRS UMR8104, Paris, France.,Faculty of Health, University of Paris Cité, Paris, France
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4
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Nühn MM, Gumbs SBH, Buchholtz NVEJ, Jannink LM, Gharu L, de Witte LD, Wensing AMJ, Lewin SR, Nijhuis M, Symons J. Shock and kill within the CNS: A promising HIV eradication approach? J Leukoc Biol 2022; 112:1297-1315. [PMID: 36148896 PMCID: PMC9826147 DOI: 10.1002/jlb.5vmr0122-046rrr] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 08/12/2022] [Accepted: 08/15/2022] [Indexed: 01/18/2023] Open
Abstract
The most studied HIV eradication approach is the "shock and kill" strategy, which aims to reactivate the latent reservoir by latency reversing agents (LRAs) and allowing elimination of these cells by immune-mediated clearance or viral cytopathic effects. The CNS is an anatomic compartment in which (persistent) HIV plays an important role in HIV-associated neurocognitive disorder. Restriction of the CNS by the blood-brain barrier is important for maintenance of homeostasis of the CNS microenvironment, which includes CNS-specific cell types, expression of transcription factors, and altered immune surveillance. Within the CNS predominantly myeloid cells such as microglia and perivascular macrophages are thought to be a reservoir of persistent HIV infection. Nevertheless, infection of T cells and astrocytes might also impact HIV infection in the CNS. Genetic adaptation to this microenvironment results in genetically distinct, compartmentalized viral populations with differences in transcription profiles. Because of these differences in transcription profiles, LRAs might have different effects within the CNS as compared with the periphery. Moreover, reactivation of HIV in the brain and elimination of cells within the CNS might be complex and could have detrimental consequences. Finally, independent of activity on latent HIV, LRAs themselves can have adverse neurologic effects. We provide an extensive overview of the current knowledge on compartmentalized (persistent) HIV infection in the CNS and on the "shock and kill" strategy. Subsequently, we reflect on the impact and promise of the "shock and kill" strategy on the elimination of persistent HIV in the CNS.
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Affiliation(s)
- Marieke M. Nühn
- Translational Virology, Department of Medical MicrobiologyUniversity Medical CenterUtrechtthe Netherlands
| | - Stephanie B. H. Gumbs
- Translational Virology, Department of Medical MicrobiologyUniversity Medical CenterUtrechtthe Netherlands
| | - Ninée V. E. J. Buchholtz
- Translational Virology, Department of Medical MicrobiologyUniversity Medical CenterUtrechtthe Netherlands
| | - Lisanne M. Jannink
- Translational Virology, Department of Medical MicrobiologyUniversity Medical CenterUtrechtthe Netherlands
| | - Lavina Gharu
- Translational Virology, Department of Medical MicrobiologyUniversity Medical CenterUtrechtthe Netherlands
| | - Lot D. de Witte
- Translational Virology, Department of Medical MicrobiologyUniversity Medical CenterUtrechtthe Netherlands,Department of PsychiatryIcahn School of MedicineNew YorkNew YorkUSA
| | - Annemarie M. J. Wensing
- Translational Virology, Department of Medical MicrobiologyUniversity Medical CenterUtrechtthe Netherlands
| | - Sharon R. Lewin
- Department of Infectious DiseasesThe University of Melbourne at the Peter Doherty Institute of Immunity and InfectionMelbourneVICAustralia,Victorian Infectious Diseases ServiceThe Royal Melbourne Hospital at the Peter Doherty Institute of Immunity and InfectionMelbourneVICAustralia,Department of Infectious DiseasesAlfred Hospital and Monash UniversityMelbourneVICAustralia
| | - Monique Nijhuis
- Translational Virology, Department of Medical MicrobiologyUniversity Medical CenterUtrechtthe Netherlands
| | - Jori Symons
- Translational Virology, Department of Medical MicrobiologyUniversity Medical CenterUtrechtthe Netherlands
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5
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Han M, Cantaloube-Ferrieu V, Xie M, Armani-Tourret M, Woottum M, Pagès JC, Colin P, Lagane B, Benichou S. HIV-1 cell-to-cell spread overcomes the virus entry block of non-macrophage-tropic strains in macrophages. PLoS Pathog 2022; 18:e1010335. [PMID: 35622876 PMCID: PMC9182568 DOI: 10.1371/journal.ppat.1010335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 06/09/2022] [Accepted: 05/09/2022] [Indexed: 11/19/2022] Open
Abstract
Macrophages (MΦ) are increasingly recognized as HIV-1 target cells involved in the pathogenesis and persistence of infection. Paradoxically, in vitro infection assays suggest that virus isolates are mostly T-cell-tropic and rarely MΦ-tropic. The latter are assumed to emerge under CD4+ T-cell paucity in tissues such as the brain or at late stage when the CD4 T-cell count declines. However, assays to qualify HIV-1 tropism use cell-free viral particles and may not fully reflect the conditions of in vivo MΦ infection through cell-to-cell viral transfer. Here, we investigated the capacity of viruses expressing primary envelope glycoproteins (Envs) with CCR5 and/or CXCR4 usage from different stages of infection, including transmitted/founder Envs, to infect MΦ by a cell-free mode and through cell-to-cell transfer from infected CD4+ T cells. The results show that most viruses were unable to enter MΦ as cell-free particles, in agreement with the current view that non-M-tropic viruses inefficiently use CD4 and/or CCR5 or CXCR4 entry receptors on MΦ. In contrast, all viruses could be effectively cell-to-cell transferred to MΦ from infected CD4+ T cells. We further showed that viral transfer proceeded through Env-dependent cell-cell fusion of infected T cells with MΦ targets, leading to the formation of productively infected multinucleated giant cells. Compared to cell-free infection, infected T-cell/MΦ contacts showed enhanced interactions of R5 M- and non-M-tropic Envs with CD4 and CCR5, resulting in a reduced dependence on receptor expression levels on MΦ for viral entry. Altogether, our results show that virus cell-to-cell transfer overcomes the entry block of isolates initially defined as non-macrophage-tropic, indicating that HIV-1 has a more prevalent tropism for MΦ than initially suggested. This sheds light into the role of this route of virus cell-to-cell transfer to MΦ in CD4+ T cell rich tissues for HIV-1 transmission, dissemination and formation of tissue viral reservoirs.
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Affiliation(s)
- Mingyu Han
- Institut Cochin, Inserm U1016, Paris, France
- CNRS, UMR8104, Paris, France
- Université de Paris, Paris, France
| | | | - Maorong Xie
- Institut Cochin, Inserm U1016, Paris, France
- CNRS, UMR8104, Paris, France
- Université de Paris, Paris, France
| | | | - Marie Woottum
- Institut Cochin, Inserm U1016, Paris, France
- CNRS, UMR8104, Paris, France
- Université de Paris, Paris, France
| | - Jean-Christophe Pagès
- Institut RESTORE, Université de Toulouse, CNRS U-5070, EFS, ENVT, Inserm U1301, Toulouse, France
| | - Philippe Colin
- Infinity, Université de Toulouse, CNRS, INSERM, UPS, Toulouse, France
| | - Bernard Lagane
- Infinity, Université de Toulouse, CNRS, INSERM, UPS, Toulouse, France
- * E-mail: (BL); (SB)
| | - Serge Benichou
- Institut Cochin, Inserm U1016, Paris, France
- CNRS, UMR8104, Paris, France
- Université de Paris, Paris, France
- * E-mail: (BL); (SB)
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6
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Functional and Highly Cross-Linkable HIV-1 Envelope Glycoproteins Enriched in a Pretriggered Conformation. J Virol 2022; 96:e0166821. [PMID: 35343783 DOI: 10.1128/jvi.01668-21] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Binding to the receptor, CD4, drives the pretriggered, "closed" (state-1) conformation of the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) trimer into more "open" conformations (states 2 and 3). Broadly neutralizing antibodies, which are elicited inefficiently, mostly recognize the state-1 Env conformation, whereas the more commonly elicited poorly neutralizing antibodies recognize states 2/3. HIV-1 Env metastability has created challenges for defining the state-1 structure and developing immunogens mimicking this labile conformation. The availability of functional state-1 Envs that can be efficiently cross-linked at lysine and/or acidic amino acid residues might assist these endeavors. To that end, we modified HIV-1AD8 Env, which exhibits an intermediate level of triggerability by CD4. We introduced lysine/acidic residues at positions that exhibit such polymorphisms in natural HIV-1 strains. Env changes that were tolerated with respect to gp120-gp41 processing, subunit association, and virus entry were further combined. Two common polymorphisms, Q114E and Q567K, as well as a known variant, A582T, additively rendered pseudoviruses resistant to cold, soluble CD4, and a CD4-mimetic compound, phenotypes indicative of stabilization of the pretriggered state-1 Env conformation. Combining these changes resulted in two lysine-rich HIV-1AD8 Env variants (E.2 and AE.2) with neutralization- and cold-resistant phenotypes comparable to those of natural, less triggerable tier 2/3 HIV-1 isolates. Compared with these and the parental Envs, the E.2 and AE.2 Envs were cleaved more efficiently and exhibited stronger gp120-trimer association in detergent lysates. These highly cross-linkable Envs enriched in a pretriggered conformation should assist characterization of the structure and immunogenicity of this labile state. IMPORTANCE The development of an efficient vaccine is critical for combating HIV-1 infection worldwide. However, the instability of the pretriggered shape (state 1) of the viral envelope glycoprotein (Env) makes it difficult to raise neutralizing antibodies against HIV-1. Here, by introducing multiple changes in Env, we derived two HIV-1 Env variants that are enriched in state 1 and can be efficiently cross-linked to maintain this shape. These Env complexes are more stable in detergent, assisting their purification. Thus, our study provides a path to a better characterization of the native pretriggered Env, which should assist vaccine development.
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7
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HIV-1 entry: Duels between Env and host antiviral transmembrane proteins on the surface of virus particles. Curr Opin Virol 2021; 50:59-68. [PMID: 34390925 DOI: 10.1016/j.coviro.2021.07.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Revised: 07/20/2021] [Accepted: 07/21/2021] [Indexed: 12/18/2022]
Abstract
Human Immunodeficiency Virus type-1 (HIV-1) is the causative agent of AIDS. Its entry step is mediated by the envelope glycoprotein (Env). During the entry process, Env vastly changes its conformation. While non-liganded Env tends to have a closed structure, receptor-binding of Env opens its conformation, which leads to virus-cell membrane fusion. Single-molecule fluorescence resonance energy transfer (smFRET) imaging allows observation of these conformational changes on the virion surface. Nascent HIV-1 particles incorporate multiple host transmembrane proteins, some of which inhibit the entry process. The Env structure or its dynamics may determine the effectiveness of these antiviral mechanisms. Here, we review recent findings about the Env conformation changes on virus particles and inhibition of Env activities by virion-incorporated host transmembrane proteins.
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8
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Nath A, Johnson TP. Mechanisms of viral persistence in the brain and therapeutic approaches. FEBS J 2021; 289:2145-2161. [PMID: 33844441 DOI: 10.1111/febs.15871] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 03/31/2021] [Accepted: 04/09/2021] [Indexed: 12/16/2022]
Abstract
There is growing recognition of the diversity of viruses that can infect the cells of the central nervous system (CNS). While the majority of CNS infections are successfully cleared by the immune response, some viral infections persist in the CNS. As opposed to resolved infections, persistent viruses can contribute to ongoing tissue damage and neuroinflammatory processes. In this manuscript, we provide an overview of the current understanding of factors that lead to viral persistence in the CNS including how viruses enter the brain, how these pathogens evade antiviral immune system responses, and how viruses survive and transmit within the CNS. Further, as the CNS may serve as a unique viral reservoir, we examine the ways in which persistent viruses in the CNS are being targeted therapeutically.
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Affiliation(s)
- Avindra Nath
- Section of Infections of the Nervous System, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Tory P Johnson
- Section of Infections of the Nervous System, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.,Department of Neurology, Johns Hopkins University, Baltimore, MD, USA
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9
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A Single Substitution in gp41 Modulates the Neutralization Profile of SHIV during In Vivo Adaptation. Cell Rep 2020; 27:2593-2607.e5. [PMID: 31141685 DOI: 10.1016/j.celrep.2019.04.108] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 03/16/2019] [Accepted: 04/26/2019] [Indexed: 12/13/2022] Open
Abstract
The HIV-1 envelope glycoprotein (Env) maintains a delicate balance between mediating viral entry and escaping antibody neutralization. Adaptation during transmission of neutralization-sensitive Envs with an "open" conformation remains poorly understood. By passaging a replication-competent simian-human immunodeficiency virus carrying a highly neutralization-sensitive Env (SHIVCNE40) in rhesus macaques, we show that SHIVCNE40 develops enhanced replication kinetics associated with neutralization resistance against antibodies and autologous serum. A gp41 substitution, E658K, functions as the major determinant for these properties. Structural modeling and functional verification indicate that the substitution disrupts an intermolecular salt bridge with the neighboring protomer, thereby promoting fusion and facilitating immune evasion. This effect is applicable across diverse HIV-1 subtypes. Our results highlight the critical role of gp41 in shaping the neutralization profile and the overall conformation of Env during viral adaptation. The unique intermolecular salt bridge could potentially be utilized for rational vaccine design involving more stable HIV-1 envelope trimers.
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10
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Dhiman K, Nath SK, Ashish. Monomeric human soluble CD4 dimerizes at physiological temperature: VTSAXS data based modeling and screening of retardant molecules. J Biomol Struct Dyn 2020; 39:3813-3824. [PMID: 32425101 DOI: 10.1080/07391102.2020.1771422] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Earlier, solution small angle X-ray scattering (SAXS) data at 10 °C showed that soluble CD4 (sCD4; 1 mg/ml) is monomer with shape similar to single chain in crystal structures of its dimer. Query remained whether the dimeric state of CD4 can form independent of packing effects of crystal? Taking cue from other systems, we explored heat induced possible association of native shapes of sCD4 by variable temperature SAXS (VTSAXS) experiments. The predominant particle size increased consistently with temperature and around 35-40 °C, the estimated mass indicated dimeric state in solution. Furthermore, the observed association was found to be reversible to certain extent. Using SAXS profile representing dimer and crystal structure of monomer, we solved models of CD4 dimers which were dominated by D4-D4 interactions and appeared "wobbling" about the crystal structure of dimeric CD4, convincing pre-existence of crystal-like association in solution. To break the dimerization, we theoretically screened for small molecules binding to dimeric interface of D4 domain. Additionally, as negative control or not expecting to interfere, we searched molecules preferentially docking on the apex of D1 domain. VTSAXS experiments of CD4 + molecules at ∼1:3 molar ratio showed that as expected few D4 reactive hits could retard dimerization, yet surprisingly molecules which docked at D1 domain could also derail dimerization. Additional analysis led to conclusion that there lies a systematic communication network across the structural length of sCD4 which senses binding to self and other molecules, and our work can be used to develop new (or re-purpose known) molecules as CD4-reactive immunosuppressive agents.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Kanika Dhiman
- Protein Science and Engineering, CSIR-Institute of Microbial Technology, Chandigarh, India
| | - Samir Kumar Nath
- Protein Science and Engineering, CSIR-Institute of Microbial Technology, Chandigarh, India
| | - Ashish
- Protein Science and Engineering, CSIR-Institute of Microbial Technology, Chandigarh, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
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11
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A minor population of macrophage-tropic HIV-1 variants is identified in recrudescing viremia following analytic treatment interruption. Proc Natl Acad Sci U S A 2020; 117:9981-9990. [PMID: 32300019 DOI: 10.1073/pnas.1917034117] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
HIV-1 persists in cellular reservoirs that can reignite viremia if antiretroviral therapy (ART) is interrupted. Therefore, insight into the nature of those reservoirs may be revealed from the composition of recrudescing viremia following treatment cessation. A minor population of macrophage-tropic (M-tropic) viruses was identified in a library of recombinant viruses constructed with individual envelope genes that were obtained from plasma of six individuals undergoing analytic treatment interruption (ATI). M-tropic viruses could also be enriched from post-ATI plasma using macrophage-specific (CD14) but not CD4+ T cell-specific (CD3) antibodies, suggesting that M-tropic viruses had a macrophage origin. Molecular clock analysis indicated that the establishment of M-tropic HIV-1 variants predated ATI. Collectively, these data suggest that macrophages are a viral reservoir in HIV-1-infected individuals on effective ART and that M-tropic variants can appear in rebounding viremia when treatment is interrupted. These findings have implications for the design of curative strategies for HIV-1.
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12
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Abstract
PURPOSE OF REVIEW The purpose of this review is to summarize the current knowledge on the role of CD4+ T lymphocytes leading to HIV assault and persistence in the central nervous system (CNS) and the elimination of HIV-infected CNS resident cells by CD8+ T lymphocytes. RECENT FINDINGS HIV targets the CNS early in infection, and HIV-infected individuals suffer from mild forms of neurological impairments even under antiretroviral therapy (ART). CD4+ T cells and monocytes mediate HIV entry into the brain and constitute a source for HIV persistence and neuronal damage. HIV-specific CD8+ T cells are also massively recruited in the CNS in acute infection to control viral replication but cannot eliminate HIV-infected cells within the CNS. This review summarizes the involvement of CD4+ T cells in seeding and maintaining HIV infection in the brain and describes the involvement of CD8+ T cells in HIV neuropathogenesis, playing a role still to be deciphered, either beneficial in eliminating HIV-infected cells or deleterious in releasing inflammatory cytokines.
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13
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Bertram KM, Tong O, Royle C, Turville SG, Nasr N, Cunningham AL, Harman AN. Manipulation of Mononuclear Phagocytes by HIV: Implications for Early Transmission Events. Front Immunol 2019; 10:2263. [PMID: 31616434 PMCID: PMC6768965 DOI: 10.3389/fimmu.2019.02263] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 09/09/2019] [Indexed: 12/11/2022] Open
Abstract
Mononuclear phagocytes are antigen presenting cells that play a key role in linking the innate and adaptive immune systems. In tissue, these consist of Langerhans cells, dendritic cells and macrophages, all of which express the key HIV entry receptors CD4 and CCR5 making them directly infectible with HIV. Mononuclear phagocytes are the first cells of the immune system to interact with invading pathogens such as HIV. Each cell type expresses a specific repertoire of pathogen binding receptors which triggers pathogen uptake and the release of innate immune cytokines. Langerhans cells and dendritic cells migrate to lymph nodes and present antigens to CD4 T cells, whereas macrophages remain tissue resident. Here we review how HIV-1 manipulates these cells by blocking their ability to produce innate immune cytokines and taking advantage of their antigen presenting cell function in order to gain transport to its primary target cells, CD4 T cells.
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Affiliation(s)
- Kirstie Melissa Bertram
- School of Medical Sciences, University of Sydney, Sydney, NSW, Australia.,Center for Virus Research, The Westmead Institute for Medical Research, Sydney, NSW, Australia
| | - Orion Tong
- School of Medical Sciences, University of Sydney, Sydney, NSW, Australia.,Center for Virus Research, The Westmead Institute for Medical Research, Sydney, NSW, Australia
| | - Caroline Royle
- School of Medical Sciences, University of Sydney, Sydney, NSW, Australia.,Center for Virus Research, The Westmead Institute for Medical Research, Sydney, NSW, Australia
| | - Stuart Grant Turville
- HIV Biology, Kirby Institute, Kensington, NSW, Australia.,The University of New South Whales, Sydney, NSW, Australia
| | - Najla Nasr
- School of Medical Sciences, University of Sydney, Sydney, NSW, Australia.,Center for Virus Research, The Westmead Institute for Medical Research, Sydney, NSW, Australia
| | - Anthony Lawrence Cunningham
- School of Medical Sciences, University of Sydney, Sydney, NSW, Australia.,Center for Virus Research, The Westmead Institute for Medical Research, Sydney, NSW, Australia
| | - Andrew Nicholas Harman
- School of Medical Sciences, University of Sydney, Sydney, NSW, Australia.,Center for Virus Research, The Westmead Institute for Medical Research, Sydney, NSW, Australia
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14
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Broadly resistant HIV-1 against CD4-binding site neutralizing antibodies. PLoS Pathog 2019; 15:e1007819. [PMID: 31194843 PMCID: PMC6592578 DOI: 10.1371/journal.ppat.1007819] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Revised: 06/25/2019] [Accepted: 05/07/2019] [Indexed: 01/15/2023] Open
Abstract
Recently identified broadly neutralizing antibodies (bnAbs) show great potential for clinical interventions against HIV-1 infection. However, resistant strains may impose substantial challenges. Here, we report on the identification and characterization of a panel of HIV-1 strains with broad and potent resistance against a large number of bnAbs, particularly those targeting the CD4-binding site (CD4bs). Site-directed mutagenesis revealed that several key epitope mutations facilitate resistance and are located in the inner domain, loop D, and β23/loop V5/β24 of HIV-1 gp120. The resistance is largely correlated with binding affinity of antibodies to the envelope trimers expressed on the cell surface. Our results therefore demonstrate the existence of broadly resistant HIV-1 strains against CD4bs neutralizing antibodies. Treatment strategies based on the CD4bs bnAbs must overcome such resistance to achieve optimal clinical outcomes. Recently identified broadly neutralizing antibodies (bnAbs) show great potential for clinical interventions against HIV-1 infection. Among the bnAbs isolated to date, those targeting the CD4bs are the most abundant and thoroughly studied as they disrupt the crucial step of viral interaction with the cellular receptor molecule CD4. Despite the superior potency and breadth of these CD4bs bnAbs, each fails to neutralize a small but significant portion of pseudotyped virus panels. Here, we report on the identification and characterization of a panel of HIV-1 strains with broad and potent resistance against a large number of bnAbs, particularly those targeting the CD4bs. Resistance is largely attributed to mutated residues within the epitopes or steric hindrance imposed by the bulky side-chain or glycan shield of the mutated residues, and is largely correlated with reduced binding avidity of the antibody to the quaternary trimeric envelope protein expressed on the surface of the transfected cells. Treatment strategies based on the CD4bs bnAbs therefore must overcome such resistance to achieve optimal clinical outcomes.
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15
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Doi N, Yokoyama M, Koma T, Kotani O, Sato H, Adachi A, Nomaguchi M. Concomitant Enhancement of HIV-1 Replication Potential and Neutralization-Resistance in Concert With Three Adaptive Mutations in Env V1/C2/C4 Domains. Front Microbiol 2019; 10:2. [PMID: 30705669 PMCID: PMC6344430 DOI: 10.3389/fmicb.2019.00002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 01/04/2019] [Indexed: 12/23/2022] Open
Abstract
HIV-1 Env protein functions in the entry process and is the target of neutralizing antibodies. Its intrinsically high mutation rate is certainly one of driving forces for persistence/survival in hosts. For optimal replication in various environments, HIV-1 Env must continue to adapt and evolve through balancing sometimes incompatible function, replication fitness, and neutralization sensitivity. We have previously reported that adapted viruses emerge in repeated and prolonged cultures of cells originally infected with a macaque-tropic HIV-1NL4-3 derivative. We have also shown that the adapted viral clones exhibit enhanced growth potentials both in macaque PBMCs and individuals, and that three single-amino acid mutations are present in their Env V1/C2/C4 domains. In this study, we investigated how lab-adapted and highly neutralization-sensitive HIV-1NL4-3 adapts its Env to macaque cells with strongly replication-restrictive nature for HIV-1. While a single and two mutations gave a significantly enhanced replication phenotype in a macaque cell line and also in human cell lines that stably express either human CD4 or macaque CD4, the virus simultaneously carrying the three adaptive mutations always grew best. Entry kinetics of parental and triple mutant viruses were similar, whereas the mutant was significantly more readily inhibited for its infectivity by soluble CD4 than parental virus. Furthermore, molecular dynamics simulations of the Env ectodomain (gp120 and gp41 ectodomain) bound with CD4 suggest that the three mutations increase binding affinity of Env for CD4 in solution. Thus, it is quite likely that the affinity for CD4 of the mutant Env is enhanced relative to the parental Env. Neutralization sensitivity of the triple mutant to CD4 binding site antibodies was not significantly different from that of parental virus, whereas the mutant exhibited a considerably higher resistance against neutralization by a CD4-induced epitope antibody and Env trimer-targeting V1/V2 antibodies. These results suggest that the three adaptive mutations cooperatively promote viral growth via increased CD4 affinity, and also that they enhance viral resistance to several neutralization antibodies by changing the Env-trimer conformation. In total, we have verified here an HIV-1 adaptation pathway in host cells and individuals involving Env derived from a lab-adapted and highly neutralization-sensitive clone.
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Affiliation(s)
- Naoya Doi
- Department of Microbiology, Tokushima University Graduate School of Medical Sciences, Tokushima, Japan
| | - Masaru Yokoyama
- Laboratory of Viral Genomics, Pathogen Genomics Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Takaaki Koma
- Department of Microbiology, Tokushima University Graduate School of Medical Sciences, Tokushima, Japan
| | - Osamu Kotani
- Laboratory of Viral Genomics, Pathogen Genomics Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Hironori Sato
- Laboratory of Viral Genomics, Pathogen Genomics Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Akio Adachi
- Department of Microbiology, Kansai Medical University, Osaka, Japan
| | - Masako Nomaguchi
- Department of Microbiology, Tokushima University Graduate School of Medical Sciences, Tokushima, Japan
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16
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Heidary M, Nasiri MJ, Mirsaeidi M, Jazi FM, Khoshnood S, Drancourt M, Darban-Sarokhalil D. Mycobacterium avium complex infection in patients with human immunodeficiency virus: A systematic review and meta-analysis. J Cell Physiol 2018; 234:9994-10001. [PMID: 30548598 DOI: 10.1002/jcp.27859] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 11/13/2018] [Indexed: 11/11/2022]
Abstract
BACKGROUND Mycobacterium avium-intracellulare complex (MAC) is one of the leading causes of death among people living with human immunodeficiency virus (HIV). The current study was aimed to determine the frequency of MAC infection in patients infected with HIV. METHODS Embase, PubMed, and Web of Science were searched for relevant studies. All statistical analyses were performed by STATA version 14. RESULTS From 6,627 retrieved articles, 23 were included in the final analysis. A total of 18,463 patients with HIV were included in the analysis. The frequency of MAC infection in patients with HIV was found to be 10.6% (95% confidence interval, 6.9-14.2). CONCLUSION The relatively large fractions of HIV-infected patients were coinfected with MAC, which may poses significant public health problems. Continued progress in the development of rapid diagnostic methods and preventive therapy for MAC should lead to further improvements in survival and quality of life in patients with HIV.
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Affiliation(s)
- Mohsen Heidary
- Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.,Student Research Committee, School of Allied Medical Sciences, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Javad Nasiri
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mehdi Mirsaeidi
- Department of Medicine, Division of Pulmonary, Critical Care, Sleep and Allergy, University of Miami, Coral Gables, Florida
| | - Faramarz Masjedian Jazi
- Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Saeed Khoshnood
- Department of Microbiology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.,Student Research Committee, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Michel Drancourt
- Aix-Marseille-Univ., IRD, MEPHI, IHU Méditerranée Infection, Marseille, France
| | - Davood Darban-Sarokhalil
- Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
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17
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Colin P, Zhou Z, Staropoli I, Garcia-Perez J, Gasser R, Armani-Tourret M, Benureau Y, Gonzalez N, Jin J, Connell BJ, Raymond S, Delobel P, Izopet J, Lortat-Jacob H, Alcami J, Arenzana-Seisdedos F, Brelot A, Lagane B. CCR5 structural plasticity shapes HIV-1 phenotypic properties. PLoS Pathog 2018; 14:e1007432. [PMID: 30521629 PMCID: PMC6283471 DOI: 10.1371/journal.ppat.1007432] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 10/24/2018] [Indexed: 01/20/2023] Open
Abstract
CCR5 plays immune functions and is the coreceptor for R5 HIV-1 strains. It exists in diverse conformations and oligomerization states. We interrogated the significance of the CCR5 structural diversity on HIV-1 infection. We show that envelope glycoproteins (gp120s) from different HIV-1 strains exhibit divergent binding levels to CCR5 on cell lines and primary cells, but not to CD4 or the CD4i monoclonal antibody E51. This owed to differential binding of the gp120s to different CCR5 populations, which exist in varying quantities at the cell surface and are differentially expressed between different cell types. Some, but not all, of these populations are antigenically distinct conformations of the coreceptor. The different binding levels of gp120s also correspond to differences in their capacity to bind CCR5 dimers/oligomers. Mutating the CCR5 dimerization interface changed conformation of the CCR5 homodimers and modulated differentially the binding of distinct gp120s. Env-pseudotyped viruses also use particular CCR5 conformations for entry, which may differ between different viruses and represent a subset of those binding gp120s. In particular, even if gp120s can bind both CCR5 monomers and oligomers, impairment of CCR5 oligomerization improved viral entry, suggesting that HIV-1 prefers monomers for entry. From a functional standpoint, we illustrate that the nature of the CCR5 molecules to which gp120/HIV-1 binds shapes sensitivity to inhibition by CCR5 ligands and cellular tropism. Differences exist in the CCR5 populations between T-cells and macrophages, and this is associated with differential capacity to bind gp120s and to support viral entry. In macrophages, CCR5 structural plasticity is critical for entry of blood-derived R5 isolates, which, in contrast to prototypical M-tropic strains from brain tissues, cannot benefit from enhanced affinity for CD4. Collectively, our results support a role for CCR5 heterogeneity in diversifying the phenotypic properties of HIV-1 isolates and provide new clues for development of CCR5-targeting drugs.
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Affiliation(s)
- Philippe Colin
- Viral Pathogenesis Unit, Department of Virology, Institut Pasteur, Paris, France
- INSERM Unit U1108, Institut Pasteur, Paris, France
- Paris Diderot University, Sorbonne Paris Cité, Cellule Pasteur, Rue du Docteur Roux, Paris, France
| | - Zhicheng Zhou
- Viral Pathogenesis Unit, Department of Virology, Institut Pasteur, Paris, France
- INSERM Unit U1108, Institut Pasteur, Paris, France
| | - Isabelle Staropoli
- Viral Pathogenesis Unit, Department of Virology, Institut Pasteur, Paris, France
- INSERM Unit U1108, Institut Pasteur, Paris, France
| | | | - Romain Gasser
- Centre de Physiopathologie Toulouse-Purpan (CPTP), Université de Toulouse, CNRS, Inserm, UPS, Toulouse, France
| | - Marie Armani-Tourret
- Centre de Physiopathologie Toulouse-Purpan (CPTP), Université de Toulouse, CNRS, Inserm, UPS, Toulouse, France
| | - Yann Benureau
- Viral Pathogenesis Unit, Department of Virology, Institut Pasteur, Paris, France
- INSERM Unit U1108, Institut Pasteur, Paris, France
| | - Nuria Gonzalez
- AIDS Immunopathogenesis Unit, Instituto de Salud Carlos III, Madrid, Spain
| | - Jun Jin
- Viral Pathogenesis Unit, Department of Virology, Institut Pasteur, Paris, France
- INSERM Unit U1108, Institut Pasteur, Paris, France
| | - Bridgette J. Connell
- Grenoble Alpes University, CNRS, CEA, Institut de Biologie Structurale (IBS), Grenoble, France
| | - Stéphanie Raymond
- Centre de Physiopathologie Toulouse-Purpan (CPTP), Université de Toulouse, CNRS, Inserm, UPS, Toulouse, France
- CHU de Toulouse, Laboratoire de Virologie, Toulouse, France
| | - Pierre Delobel
- Centre de Physiopathologie Toulouse-Purpan (CPTP), Université de Toulouse, CNRS, Inserm, UPS, Toulouse, France
- CHU de Toulouse, Service des Maladies Infectieuses et Tropicales, Toulouse, France
| | - Jacques Izopet
- Centre de Physiopathologie Toulouse-Purpan (CPTP), Université de Toulouse, CNRS, Inserm, UPS, Toulouse, France
- CHU de Toulouse, Laboratoire de Virologie, Toulouse, France
| | - Hugues Lortat-Jacob
- Grenoble Alpes University, CNRS, CEA, Institut de Biologie Structurale (IBS), Grenoble, France
| | - Jose Alcami
- AIDS Immunopathogenesis Unit, Instituto de Salud Carlos III, Madrid, Spain
| | - Fernando Arenzana-Seisdedos
- Viral Pathogenesis Unit, Department of Virology, Institut Pasteur, Paris, France
- INSERM Unit U1108, Institut Pasteur, Paris, France
| | - Anne Brelot
- Viral Pathogenesis Unit, Department of Virology, Institut Pasteur, Paris, France
- INSERM Unit U1108, Institut Pasteur, Paris, France
| | - Bernard Lagane
- Viral Pathogenesis Unit, Department of Virology, Institut Pasteur, Paris, France
- INSERM Unit U1108, Institut Pasteur, Paris, France
- Centre de Physiopathologie Toulouse-Purpan (CPTP), Université de Toulouse, CNRS, Inserm, UPS, Toulouse, France
- * E-mail:
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18
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Brese RL, Gonzalez-Perez MP, Koch M, O'Connell O, Luzuriaga K, Somasundaran M, Clapham PR, Dollar JJ, Nolan DJ, Rose R, Lamers SL. Ultradeep single-molecule real-time sequencing of HIV envelope reveals complete compartmentalization of highly macrophage-tropic R5 proviral variants in brain and CXCR4-using variants in immune and peripheral tissues. J Neurovirol 2018; 24:439-453. [PMID: 29687407 PMCID: PMC7281851 DOI: 10.1007/s13365-018-0633-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 02/28/2018] [Accepted: 03/19/2018] [Indexed: 01/07/2023]
Abstract
Despite combined antiretroviral therapy (cART), HIV+ patients still develop neurological disorders, which may be due to persistent HIV infection and selective evolution in brain tissues. Single-molecule real-time (SMRT) sequencing technology offers an improved opportunity to study the relationship among HIV isolates in the brain and lymphoid tissues because it is capable of generating thousands of long sequence reads in a single run. Here, we used SMRT sequencing to generate ~ 50,000 high-quality full-length HIV envelope sequences (> 2200 bp) from seven autopsy tissues from an HIV+/cART+ subject, including three brain and four non-brain sites. Sanger sequencing was used for comparison with SMRT data and to clone functional pseudoviruses for in vitro tropism assays. Phylogenetic analysis demonstrated that brain-derived HIV was compartmentalized from HIV outside the brain and that the variants from each of the three brain tissues grouped independently. Variants from all peripheral tissues were intermixed on the tree but independent of the brain clades. Due to the large number of sequences, a clustering analysis at three similarity thresholds (99, 99.5, and 99.9%) was also performed. All brain sequences clustered exclusive of any non-brain sequences at all thresholds; however, frontal lobe sequences clustered independently of occipital and parietal lobes. Translated sequences revealed potentially functional differences between brain and non-brain sequences in the location of putative N-linked glycosylation sites (N-sites), V1 length, V3 charge, and the number of V4 N-sites. All brain sequences were predicted to use the CCR5 co-receptor, while most non-brain sequences were predicted to use CXCR4 co-receptor. Tropism results were confirmed by in vitro infection assays. The study is the first to use a SMRT sequencing approach to study HIV compartmentalization in tissues and supports other reports of limited trafficking between brain and non-brain sequences during cART. Due to the long sequence length, we could observe changes along the entire envelope gene, likely caused by differential selective pressure in the brain that may contribute to neurological disease.
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Affiliation(s)
- Robin L Brese
- Program in Molecular Medicine, University of Massachusetts Medical School, Biotech 2, 373 Plantation Street, Worcester, MA, 01605, USA
| | - Maria Paz Gonzalez-Perez
- Program in Molecular Medicine, University of Massachusetts Medical School, Biotech 2, 373 Plantation Street, Worcester, MA, 01605, USA
| | - Matthew Koch
- Program in Molecular Medicine, University of Massachusetts Medical School, Biotech 2, 373 Plantation Street, Worcester, MA, 01605, USA
| | - Olivia O'Connell
- Program in Molecular Medicine, University of Massachusetts Medical School, Biotech 2, 373 Plantation Street, Worcester, MA, 01605, USA
| | - Katherine Luzuriaga
- Program in Molecular Medicine, University of Massachusetts Medical School, Biotech 2, 373 Plantation Street, Worcester, MA, 01605, USA
| | - Mohan Somasundaran
- Program in Molecular Medicine, University of Massachusetts Medical School, Biotech 2, 373 Plantation Street, Worcester, MA, 01605, USA
| | - Paul R Clapham
- Program in Molecular Medicine, University of Massachusetts Medical School, Biotech 2, 373 Plantation Street, Worcester, MA, 01605, USA
| | | | - David J Nolan
- Bioinfoexperts, LLC, 718 Bayou Ln, Thibodaux, LA, 70301, USA
| | - Rebecca Rose
- Bioinfoexperts, LLC, 718 Bayou Ln, Thibodaux, LA, 70301, USA.
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19
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Phenotypic deficits in the HIV-1 envelope are associated with the maturation of a V2-directed broadly neutralizing antibody lineage. PLoS Pathog 2018; 14:e1006825. [PMID: 29370298 PMCID: PMC5806907 DOI: 10.1371/journal.ppat.1006825] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 02/09/2018] [Accepted: 12/16/2017] [Indexed: 11/19/2022] Open
Abstract
Broadly neutralizing antibodies (bnAbs) to HIV-1 can evolve after years of an iterative process of virus escape and antibody adaptation that HIV-1 vaccine design seeks to mimic. To enable this, properties that render HIV-1 envelopes (Env) capable of eliciting bnAb responses need to be defined. Here, we followed the evolution of the V2 apex directed bnAb lineage VRC26 in the HIV-1 subtype C superinfected donor CAP256 to investigate the phenotypic changes of the virus populations circulating before and during the early phases of bnAb induction. Longitudinal viruses that evolved from the VRC26-resistant primary infecting (PI) virus, the VRC26-sensitive superinfecting (SU) virus and ensuing PI-SU recombinants revealed substantial phenotypic changes in Env, with a switch in Env properties coinciding with early resistance to VRC26. Decreased sensitivity of SU-like viruses to VRC26 was linked with reduced infectivity, altered entry kinetics and lower sensitivity to neutralization after CD4 attachment. VRC26 maintained neutralization activity against cell-associated CAP256 virus, indicating that escape through the cell-cell transmission route is not a dominant escape pathway. Reduced fitness of the early escape variants and sustained sensitivity in cell-cell transmission are both features that limit virus replication, thereby impeding rapid escape. This supports a scenario where VRC26 allowed only partial viral escape for a prolonged period, possibly increasing the time window for bnAb maturation. Collectively, our data highlight the phenotypic plasticity of the HIV-1 Env in evading bnAb pressure and the need to consider phenotypic traits when selecting and designing Env immunogens. Combinations of Env variants with differential phenotypic patterns and bnAb sensitivity, as we describe here for CAP256, may maximize the potential for inducing bnAb responses by vaccination. HIV-1 infected individuals rarely develop broadly neutralizing antibodies (bnAbs) that inhibit diverse HIV-1 subtypes. As activity against the majority of HIV-1 isolates is necessary for effective immunization against HIV-1, current vaccine development seeks to generate regimens that evoke bnAb responses. Delineating why bnAbs develop in certain cases of HIV-1 infection is thus of pivotal importance. In all infected individuals, HIV-1 inevitably escapes neutralizing antibody pressure and even the most potent bnAbs cannot clear the infection from the patient where they emerged. Yet, exactly this continuous interplay between virus escape and antibody maturation is believed to be crucial in the evolution of bnAbs, with virus escape variants containing modified HIV-1 envelope (Env) proteins, the target of neutralizing antibodies that in some cases can direct the immune response towards breadth. Identifying features of naturally occurring Env proteins that are involved in evoking bnAb responses is thus of high interest. Here, we analyzed Env features of virus isolates from donor CAP256 who developed the potent V2 apex bnAb VRC26, one of the current lead bnAbs for HIV-1 therapy and vaccine development. We show that the viral escape variants that appeared soon after the onset of the VRC26 response had highly altered Env protein properties that, in addition to reducing sensitivity to VRC26, affected their capacity to infect and altered entry dynamics. This highlights constrained viral escape pathways, but also features of VRC26 that may have prevented rapid escape. We postulate that this may have resulted in a prolonged circulation of partially VRC26 sensitive viruses, hence allowing the bnAb response to mature.
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20
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Functional Stability of HIV-1 Envelope Trimer Affects Accessibility to Broadly Neutralizing Antibodies at Its Apex. J Virol 2017; 91:JVI.01216-17. [PMID: 28978711 DOI: 10.1128/jvi.01216-17] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 09/29/2017] [Indexed: 02/07/2023] Open
Abstract
The trimeric envelope glycoprotein spike (Env) of HIV-1 is the target of vaccine development to elicit broadly neutralizing antibodies (bnAbs). Env trimer instability and heterogeneity in principle make subunit interfaces inconsistent targets for the immune response. Here, we investigate how functional stability of Env relates to neutralization sensitivity to V2 bnAbs and V3 crown antibodies that engage subunit interfaces upon binding to unliganded Env. Env heterogeneity was inferred when antibodies neutralized a mutant Env with a plateau of less than 100% neutralization. A statistically significant correlation was found between the stability of mutant Envs and the MPN of V2 bnAb, PG9, as well as an inverse correlation between stability of Env and neutralization by V3 crown antibody, 447-52D. A number of Env-stabilizing mutations and V2 bnAb-enhancing mutations were identified in Env, but they did not always overlap, indicating distinct requirements of functional stabilization versus antibody recognition. Blocking complex glycosylation of Env affected V2 bnAb recognition, as previously described, but also notably increased functional stability of Env. This study shows how instability and heterogeneity affect antibody sensitivity of HIV-1 Env, which is relevant to vaccine design involving its dynamic apex.IMPORTANCE The Env trimer is the only viral protein on the surface of HIV-1 and is the target of neutralizing antibodies that reduce viral infectivity. Quaternary epitopes at the apex of the spike are recognized by some of the most potent and broadly neutralizing antibodies to date. Being that their glycan-protein hybrid epitopes are at subunit interfaces, the resulting heterogeneity can lead to partial neutralization. Here, we screened for mutations in Env that allowed for complete neutralization by the bnAbs. We found that when mutations outside V2 increased V2 bnAb recognition, they often also increased Env stability-of-function and decreased binding by narrowly neutralizing antibodies to the V3 crown. Three mutations together increased neutralization by V2 bnAb and eliminated binding by V3 crown antibodies. These results may aid the design of immunogens that elicit antibodies to the trimer apex.
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21
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Shi G, Schwartz O, Compton AA. More than meets the I: the diverse antiviral and cellular functions of interferon-induced transmembrane proteins. Retrovirology 2017; 14:53. [PMID: 29162141 PMCID: PMC5697417 DOI: 10.1186/s12977-017-0377-y] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 11/13/2017] [Indexed: 01/14/2023] Open
Abstract
The first responders of human antiviral immunity are components of the intrinsic immune response that reside within each and every one of our cells. This cell-autonomous arsenal consists of nucleic acid sensors and antiviral effectors strategically placed by evolution to detect and restrict invading viruses. While some factors are present at baseline to allow for constant surveillance of the cell interior, others are upregulated by cytokines (such as interferons) that signal a viral infection underway in neighboring cells. In this review, we highlight the multiple roles played by the interferon-induced transmembrane (IFITM) proteins during viral infection, with focuses on IFITM3 and HIV-1. Moreover, we discuss the cellular pathways in which IFITM proteins are intertwined and the various functions they have been ascribed outside the context of infection. While appreciated as broadly-acting, potent restriction factors that prevent virus infection and pathogenesis in cell culture and in vivo, questions remain regarding their precise mode of action and importance in certain viral contexts. Continued efforts to study IFITM protein function will further cement their status as critical host determinants of virus susceptibility and prioritize them in the development of new antiviral therapies.
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Affiliation(s)
- Guoli Shi
- Antiviral Immunity and Resistance Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, MD, USA
| | - Olivier Schwartz
- Virus and Immunity Unit, Institut Pasteur, Paris, France.,UMR CNRS 3569, Paris, France
| | - Alex A Compton
- Antiviral Immunity and Resistance Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, MD, USA.
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22
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HIV Fusion in Dendritic Cells Occurs Mainly at the Surface and Is Limited by Low CD4 Levels. J Virol 2017; 91:JVI.01248-17. [PMID: 28814521 DOI: 10.1128/jvi.01248-17] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 08/10/2017] [Indexed: 01/06/2023] Open
Abstract
HIV-1 poorly infects monocyte-derived dendritic cells (MDDCs). This is in large part due to SAMHD1, which restricts viral reverse transcription. Pseudotyping HIV-1 with vesicular stomatitis virus G protein (VSV-G) strongly enhances infection, suggesting that earlier steps of viral replication, including fusion, are also inefficient in MDDCs. The site of HIV-1 fusion remains controversial and may depend on the cell type, with reports indicating that it occurs at the plasma membrane or, conversely, in an endocytic compartment. Here, we examined the pathways of HIV-1 entry in MDDCs. Using a combination of temperature shift and fusion inhibitors, we show that HIV-1 fusion mainly occurs at the cell surface. We then asked whether surface levels or intracellular localization of CD4 modulates HIV-1 entry. Increasing CD4 levels strongly enhanced fusion and infection with various HIV-1 isolates, including reference and transmitted/founder strains, but not with BaL, which uses low CD4 levels for entry. Overexpressing coreceptors did not facilitate viral infection. To further study the localization of fusion events, we generated CD4 mutants carrying heterologous cytoplasmic tails (LAMP1 or Toll-like receptor 7 [TLR7]) to redirect the molecule to intracellular compartments. The intracellular CD4 mutants did not facilitate HIV-1 fusion and replication in MDDCs. Fusion of an HIV-2 isolate with MDDCs was also enhanced by increasing surface CD4 levels. Our results demonstrate that MDDCs are inefficiently infected by various HIV-1 and HIV-2 strains, in part because of low CD4 levels. In these cells, viral fusion occurs mainly at the surface, and probably not after internalization.IMPORTANCE Dendritic cells (DCs) are professional antigen-presenting cells inducing innate and adaptive immune responses. DCs express the HIV receptor CD4 and are potential target cells for HIV. There is debate about the sensitivity of DCs to productive HIV-1 and HIV-2 infection. The fusion step of the viral replication cycle is inefficient in DCs, and the underlying mechanisms are poorly characterized. We show that increasing the levels of CD4 at the plasma membrane allows more HIV fusion and productive infection in DCs. We further demonstrate that HIV fusion occurs mainly at the cell surface and not in an intracellular compartment. Our results help us understand why DCs are poorly sensitive to HIV infection.
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23
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King B, Tarr AW. How have retrovirus pseudotypes contributed to our understanding of viral entry? Future Virol 2017. [DOI: 10.2217/fvl-2017-0062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Study of virus entry into host cells is important for understanding viral tropism and pathogenesis. Studying the entry of in vitro cultured viruses is not always practicable. Study of highly pathogenic viruses, viruses that do not grow in culture, and viruses that rapidly change phenotype in vitro can all benefit from alternative models of entry. Retrovirus particles can be engineered to display the envelope proteins of heterologous enveloped viruses. This approach, broadly termed ‘pseudotyping’, is an important technique for interrogating virus entry. In this perspective we consider how retrovirus pseudotypes have addressed these challenges and improved our understanding of the entry pathways of diverse virus species, including Ebolavirus, human immunodeficiency virus and hepatitis C virus.
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Affiliation(s)
- Barnabas King
- National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust & the University of Nottingham, Nottingham, UK
- School of Life Sciences, Faculty of Medicine & Health Sciences, University of Nottingham, Nottingham, UK
| | - Alexander W Tarr
- National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust & the University of Nottingham, Nottingham, UK
- School of Life Sciences, Faculty of Medicine & Health Sciences, University of Nottingham, Nottingham, UK
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Nomaguchi M, Doi N, Koma T, Adachi A. HIV-1 mutates to adapt in fluxing environments. Microbes Infect 2017; 20:610-614. [PMID: 28859896 DOI: 10.1016/j.micinf.2017.08.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Accepted: 08/23/2017] [Indexed: 01/11/2023]
Abstract
Human immunodeficiency virus type 1 (HIV-1) is specifically adapted for replication, persistence, transmission, and survival in humans. HIV-1 is highly mutable in nature, and well responds to a variety of environmental pressures by altering its genome sequences. In this review, we have described experimental evidence that demonstrates this phantasmagoric property of HIV-1.
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Affiliation(s)
- Masako Nomaguchi
- Department of Microbiology, Tokushima University Graduate School of Medical Science, Tokushima 770-8503, Japan
| | - Naoya Doi
- Department of Microbiology, Tokushima University Graduate School of Medical Science, Tokushima 770-8503, Japan
| | - Takaaki Koma
- Department of Microbiology, Tokushima University Graduate School of Medical Science, Tokushima 770-8503, Japan
| | - Akio Adachi
- Department of Microbiology, Tokushima University Graduate School of Medical Science, Tokushima 770-8503, Japan; Department of Microbiology, Kansai Medical University, Osaka 573-1010, Japan.
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