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Schouest B, Leslie GJ, Hoxie JA, Maness NJ. Tetherin downmodulation by SIVmac Nef lost with the H196Q escape variant is restored by an upstream variant. PLoS One 2020; 15:e0225420. [PMID: 32764749 PMCID: PMC7413475 DOI: 10.1371/journal.pone.0225420] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 07/13/2020] [Indexed: 01/17/2023] Open
Abstract
The H196 residue in SIVmac239 Nef is conserved across the majority of HIV and SIV isolates, lies immediately adjacent to the AP-2 (adaptor protein 2) binding di-leucine domain (ExxxLM195), and is critical for several described AP-2 dependent Nef functions, including the downregulation of tetherin (BST-2/CD317), CD4, and others. Surprisingly, many stocks of the closely related SIVmac251 swarm virus harbor a nef allele encoding a Q196. In SIVmac239, this variant is associated with loss of multiple AP-2 dependent functions. Publicly available sequences for SIVmac251 stocks were mined for variants linked to Q196 that might compensate for functional defects associated with this residue. Variants were engineered into the SIVmac239 backbone and in Nef expression plasmids and flow cytometry was used to examine surface tetherin expression in primary CD4 T cells and surface CD4 expression in SupT1 cells engineered to express rhesus CD4. We found that SIVmac251 stocks that encode a Q196 residue in Nef uniformly also encode an upstream R191 residue. We show that R191 restores the ability of Nef to downregulate tetherin in the presence of Q196 and has a similar but less pronounced impact on CD4 expression. However, a published report showed Q196 commonly evolves to H196 in vivo, suggesting a fitness cost. R191 may represent compensatory evolution to restore the ability to downregulate tetherin lost in viruses harboring Q196.
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Affiliation(s)
- Blake Schouest
- Division of Microbiology, Tulane National Primate Research Center, Covington, LA, United States of America
| | - George J. Leslie
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States of America
| | - James A. Hoxie
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States of America
| | - Nicholas J. Maness
- Division of Microbiology, Tulane National Primate Research Center, Covington, LA, United States of America
- Department of Microbiology and Immunology, School of Medicine, Tulane University Health Sciences Center, New Orleans, LA, United States of America
- * E-mail:
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2
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Li Z, Li W, Lu M, Bess J, Chao CW, Gorman J, Terry DS, Zhang B, Zhou T, Blanchard SC, Kwong PD, Lifson JD, Mothes W, Liu J. Subnanometer structures of HIV-1 envelope trimers on aldrithiol-2-inactivated virus particles. Nat Struct Mol Biol 2020; 27:726-734. [PMID: 32601441 PMCID: PMC8138683 DOI: 10.1038/s41594-020-0452-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 05/18/2020] [Indexed: 12/12/2022]
Abstract
The HIV-1 envelope glycoprotein (Env) trimer, composed of gp120 and gp41 subunits, mediates viral entry into cells. Recombinant Env trimers have been studied structurally, but characterization of Env embedded in intact virus membranes has been limited to low resolution. Here, we deploy cryo-electron tomography and subtomogram averaging to determine the structures of Env trimers on aldrithiol-2 (AT-2)-inactivated virions in ligand-free, antibody-bound and CD4-bound forms at subnanometer resolution. Tomographic reconstructions document molecular features consistent with high-resolution structures of engineered soluble and detergent-solubilized Env trimers. One of three conformational states previously predicted by smFRET was not observed by cryo-ET, potentially owing to AT-2 inactivation. We did observe Env trimers to open in situ in response to CD4 binding, with an outward movement of gp120-variable loops and an extension of a critical gp41 helix. Overall features of Env trimer embedded in AT-2-treated virions appear well-represented by current engineered trimers.
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Affiliation(s)
- Ze Li
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, USA
- Microbial Sciences Institute, Yale University, West Haven, CT, USA
- Fudan University Shanghai Cancer Center, Institute of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Wenwei Li
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, USA
- Microbial Sciences Institute, Yale University, West Haven, CT, USA
| | - Maolin Lu
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, USA
| | - Julian Bess
- AIDS and Cancer Virus Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Cara W Chao
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Jason Gorman
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Daniel S Terry
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Baoshan Zhang
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Tongqing Zhou
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Scott C Blanchard
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Peter D Kwong
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Jeffrey D Lifson
- AIDS and Cancer Virus Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Walther Mothes
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, USA.
| | - Jun Liu
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, USA.
- Microbial Sciences Institute, Yale University, West Haven, CT, USA.
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3
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A Highly Unusual V1 Region of Env in an Elite Controller of HIV Infection. J Virol 2019; 93:JVI.00094-19. [PMID: 30842322 PMCID: PMC6498048 DOI: 10.1128/jvi.00094-19] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 02/15/2019] [Indexed: 12/15/2022] Open
Abstract
HIV elite controllers represent a remarkable minority of patients who maintain normal CD4+ T-cell counts and low or undetectable viral loads for decades in the absence of antiretroviral therapy. To examine the possible contribution of virus attenuation to elite control, we obtained a primary HIV-1 isolate from an elite controller who had been infected for 19 years, the last 10 of which were in the absence of antiretroviral therapy. Full-length sequencing of this isolate revealed a highly unusual V1 domain in Envelope (Env). The V1 domain in this HIV-1 strain was 49 amino acids, placing it in the top 1% of lengths among the 6,112 Env sequences in the Los Alamos National Laboratory online database. Furthermore, it included two additional N-glycosylation sites and a pair of cysteines suggestive of an extra disulfide loop. Virus with this Env retained good infectivity and replicative capacity; however, analysis of recombinant viruses suggested that other sequences in Env were adapted to accommodate the unusual V1 domain. While the long V1 domain did not confer resistance to neutralization by monoclonal antibodies of the V1/V2-glycan-dependent class, it did confer resistance to neutralization by monoclonal antibodies of the V3-glycan-dependent class. Our findings support results in the literature that suggest a role for long V1 regions in shielding HIV-1 from recognition by V3-directed broadly neutralizing antibodies. In the case of the elite controller described here, it seems likely that selective pressures from the humoral immune system were responsible for driving the highly unusual polymorphisms present in this HIV-1 Envelope.IMPORTANCE Elite controllers have long provided an avenue for researchers to reveal mechanisms underlying control of HIV-1. While the role of host genetic factors in facilitating elite control is well known, the possibility of infection by attenuated strains of HIV-1 has been much less studied. Here we describe an unusual viral feature found in an elite controller of HIV-1 infection and demonstrate its role in conferring escape from monoclonal antibodies of the V3-glycan class. Our results suggest that extreme variation may be needed by HIV-1 to escape neutralization by some antibody specificities.
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4
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Swanstrom AE, Del Prete GQ, Deleage C, Elser SE, Lackner AA, Hoxie JA. The SIV Envelope Glycoprotein, Viral Tropism, and Pathogenesis: Novel Insights from Nonhuman Primate Models of AIDS. Curr HIV Res 2019; 16:29-40. [PMID: 29173176 DOI: 10.2174/1570162x15666171124123116] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 10/12/2017] [Accepted: 10/13/2017] [Indexed: 12/14/2022]
Abstract
BACKGROUND Cellular tropism of human immunodeficiency virus (HIV-1) is closely linked to interactions between the viral envelope glycoprotein (Env) with CD4 and chemokine receptor family members, CCR5 and CXCR4. This interaction plays a key role in determining anatomic sites that are infected in vivo and the cascade of early and late events that result in chronic immune activation, immunosuppression and ultimately, AIDS. CD4+ T cells are critical to adaptive immune responses, and their early and rapid infection in gut lamina propria and secondary lymphoid tissues in susceptible hosts likely contributes to viral persistence and progression to disease. CD4+ macrophages are also infected, although their role in HIV-1 pathogenesis is more controversial. METHODS Pathogenic infection by simian immunodeficiency viruses (SIV) in Asian macaques as models of HIV-1 infection has enabled the impact of cellular tropism on pathogenesis to be directly probed. This review will highlight examples in which experimental interventions during SIV infection or the introduction of viral mutations have altered cellular tropism and, subsequently, pathogenesis. RESULTS Alterations to the interaction of Env and its cellular receptors has been shown to result in changes to CD4 dependence, coreceptor specificity, and viral tropism for gut CD4+ T cells and macrophages. CONCLUSION Collectively, these findings have yielded novel insights into the critical role of the viral Env and tropism as a driver of pathogenesis and host control and have helped to identify new areas for targeted interventions in therapy and prevention of HIV-1 infection.
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Affiliation(s)
- Adrienne E Swanstrom
- AIDS and Cancer Virus Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research Inc., Frederick, MD, United States
| | - Gregory Q Del Prete
- AIDS and Cancer Virus Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research Inc., Frederick, MD, United States
| | - Claire Deleage
- AIDS and Cancer Virus Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research Inc., Frederick, MD, United States
| | - Samra E Elser
- Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
| | - Andrew A Lackner
- Tulane National Primate Research Center, Covington, LA, United States
| | - James A Hoxie
- Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
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5
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van Montfort T, van der Sluis R, Darcis G, Beaty D, Groen K, Pasternak AO, Pollakis G, Vink M, Westerhout EM, Hamdi M, Bakker M, van der Putten B, Jurriaans S, Prins JH, Jeeninga R, Thomas AAM, Speijer D, Berkhout B. Dendritic cells potently purge latent HIV-1 beyond TCR-stimulation, activating the PI3K-Akt-mTOR pathway. EBioMedicine 2019; 42:97-108. [PMID: 30824386 PMCID: PMC6491380 DOI: 10.1016/j.ebiom.2019.02.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 02/01/2019] [Accepted: 02/06/2019] [Indexed: 02/06/2023] Open
Abstract
Background The latent HIV-1 reservoir in treated patients primarily consists of resting memory CD4+ T cells. Stimulating the T-cell receptor (TCR), which facilitates transition of resting into effector T cells, is the most effective strategy to purge these latently infected cells. Here we supply evidence that TCR-stimulated effector T cells still frequently harbor latent HIV-1. Methods Primary HIV-1 infected cells were used in a latency assay with or without dendritic cells (DCs) and reversion of HIV-1 latency was determined, in the presence or absence of specific pathway inhibitors. Findings Renewed TCR-stimulation or subsequent activation with latency reversing agents (LRAs) did not overcome latency. However, interaction of infected effector cells with DCs triggered further activation of latent HIV-1. When compared to TCR-stimulation only, CD4+ T cells from aviremic patients receiving TCR + DC-stimulation reversed latency more frequently. Such a “one-two punch” strategy seems ideal for purging the reservoir. We determined that DC contact activates the PI3K-Akt-mTOR pathway in CD4+ T cells. Interpretation This insight could facilitate the development of a novel class of potent LRAs that purge latent HIV beyond levels reached by T-cell activation.
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Affiliation(s)
- Thijs van Montfort
- Department of Medical Microbiology, Laboratory of Experimental Virology, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands.
| | - Renée van der Sluis
- Department of Medical Microbiology, Laboratory of Experimental Virology, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands
| | - Gilles Darcis
- Department of Medical Microbiology, Laboratory of Experimental Virology, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands; Department of Infectious Diseases, Liege University Hospital, Liege, Belgium
| | - Doyle Beaty
- Department of Medical Microbiology, Laboratory of Experimental Virology, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands
| | - Kevin Groen
- Department of Medical Microbiology, Laboratory of Experimental Virology, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands
| | - Alexander O Pasternak
- Department of Medical Microbiology, Laboratory of Experimental Virology, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands
| | - Georgios Pollakis
- Department of Clinical Infection, Microbiology and Immunology (CIMI), University of Liverpool, Liverpool, 8 West Derby Street, United Kingdom
| | - Monique Vink
- Department of Medical Microbiology, Laboratory of Experimental Virology, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands
| | - Ellen M Westerhout
- Department of Oncogenomics, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands
| | - Mohamed Hamdi
- Department of Oncogenomics, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands
| | - Margreet Bakker
- Department of Medical Microbiology, Laboratory of Experimental Virology, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands
| | - Boas van der Putten
- Department of Medical Microbiology, Laboratory of Experimental Virology, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands
| | - Suzanne Jurriaans
- Department of Medical Microbiology, Laboratory of Experimental Virology, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands
| | - Jan H Prins
- Department of Internal Medicine, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands
| | - Rienk Jeeninga
- Department of Medical Microbiology, Laboratory of Experimental Virology, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands
| | - Adri A M Thomas
- Department Developmental Biology, Faculty Beta-Science, Utrecht, Padualaan 8, 3584, CH, the Netherlands
| | - Dave Speijer
- Department of Medical Biochemistry, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands
| | - Ben Berkhout
- Department of Medical Microbiology, Laboratory of Experimental Virology, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands
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6
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Struwe WB, Chertova E, Allen JD, Seabright GE, Watanabe Y, Harvey DJ, Medina-Ramirez M, Roser JD, Smith R, Westcott D, Keele BF, Bess JW, Sanders RW, Lifson JD, Moore JP, Crispin M. Site-Specific Glycosylation of Virion-Derived HIV-1 Env Is Mimicked by a Soluble Trimeric Immunogen. Cell Rep 2018; 24:1958-1966.e5. [PMID: 30134158 PMCID: PMC6113929 DOI: 10.1016/j.celrep.2018.07.080] [Citation(s) in RCA: 101] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 06/18/2018] [Accepted: 07/24/2018] [Indexed: 12/29/2022] Open
Abstract
Many broadly neutralizing antibodies (bnAbs) against HIV-1 recognize and/or penetrate the glycan shield on native, virion-associated envelope glycoprotein (Env) spikes. The same bnAbs also bind to recombinant, soluble trimeric immunogens based on the SOSIP design. While SOSIP trimers are close structural and antigenic mimics of virion Env, the extent to which their glycan structures resemble ones on infectious viruses is undefined. Here, we compare the overall glycosylation of gp120 and gp41 subunits from BG505 (clade A) virions produced in a lymphoid cell line with those from recombinant BG505 SOSIP trimers, including CHO-derived clinical grade material. We also performed detailed site-specific analyses of gp120. Glycans relevant to key bnAb epitopes are generally similar on the recombinant SOSIP and virion-derived Env proteins, although the latter do contain hotspots of elevated glycan processing. Knowledge of native versus recombinant Env glycosylation will guide vaccine design and manufacturing programs.
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Affiliation(s)
- Weston B Struwe
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK; Chemistry Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, OX1 3TA, UK
| | - Elena Chertova
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Joel D Allen
- Biological Sciences and the Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, UK
| | - Gemma E Seabright
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK; Biological Sciences and the Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, UK
| | - Yasunori Watanabe
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK; Biological Sciences and the Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, UK
| | - David J Harvey
- Biological Sciences and the Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, UK; Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7FZ, UK
| | - Max Medina-Ramirez
- Department of Medical Microbiology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - James D Roser
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Rodman Smith
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - David Westcott
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Brandon F Keele
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Julian W Bess
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Rogier W Sanders
- Department of Microbiology and Immunology, Weill Cornell Medical College, Cornell University, New York, NY, USA; Department of Medical Microbiology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Jeffrey D Lifson
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - John P Moore
- Department of Microbiology and Immunology, Weill Cornell Medical College, Cornell University, New York, NY, USA.
| | - Max Crispin
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK; Biological Sciences and the Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, UK.
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7
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Panico M, Bouché L, Binet D, O’Connor MJ, Rahman D, Pang PC, Canis K, North SJ, Desrosiers RC, Chertova E, Keele BF, Bess JW, Lifson JD, Haslam SM, Dell A, Morris HR. Mapping the complete glycoproteome of virion-derived HIV-1 gp120 provides insights into broadly neutralizing antibody binding. Sci Rep 2016; 6:32956. [PMID: 27604319 PMCID: PMC5015092 DOI: 10.1038/srep32956] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 08/17/2016] [Indexed: 12/31/2022] Open
Abstract
The surface envelope glycoprotein (SU) of Human immunodeficiency virus type 1 (HIV-1), gp120(SU) plays an essential role in virus binding to target CD4+ T-cells and is a major vaccine target. Gp120 has remarkably high levels of N-linked glycosylation and there is considerable evidence that this "glycan shield" can help protect the virus from antibody-mediated neutralization. In recent years, however, it has become clear that gp120 glycosylation can also be included in the targets of recognition by some of the most potent broadly neutralizing antibodies. Knowing the site-specific glycosylation of gp120 can facilitate the rational design of glycopeptide antigens for HIV vaccine development. While most prior studies have focused on glycan analysis of recombinant forms of gp120, here we report the first systematic glycosylation site analysis of gp120 derived from virions produced by infected T lymphoid cells and show that a single site is exclusively substituted with complex glycans. These results should help guide the design of vaccine immunogens.
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Affiliation(s)
- Maria Panico
- Department of Life Sciences, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Laura Bouché
- Department of Life Sciences, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Daniel Binet
- BioPharmaSpec, Suite 3.1 Lido Medical Centre, St. Saviours Road, Jersey, JE2 7LA, UK
| | - Michael-John O’Connor
- BioPharmaSpec, Suite 3.1 Lido Medical Centre, St. Saviours Road, Jersey, JE2 7LA, UK
| | - Dinah Rahman
- Department of Life Sciences, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Poh-Choo Pang
- Department of Life Sciences, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Kevin Canis
- Department of Life Sciences, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Simon J. North
- Department of Life Sciences, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | | | - Elena Chertova
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, USA
| | - Brandon F. Keele
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, USA
| | - Julian W. Bess
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, USA
| | - Jeffrey D. Lifson
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, USA
| | - Stuart M. Haslam
- Department of Life Sciences, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Anne Dell
- Department of Life Sciences, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Howard R. Morris
- Department of Life Sciences, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
- BioPharmaSpec, Suite 3.1 Lido Medical Centre, St. Saviours Road, Jersey, JE2 7LA, UK
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8
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Gordon SN, Liyanage NPM, Doster MN, Vaccari M, Vargas-Inchaustegui DA, Pegu P, Schifanella L, Shen X, Tomaras GD, Rao M, Billings EA, Schwartz J, Prado I, Bobb K, Zhang W, Montefiori DC, Foulds KE, Ferrari G, Robert-Guroff M, Roederer M, Phan TB, Forthal DN, Stablein DM, Phogat S, Venzon DJ, Fouts T, Franchini G. Boosting of ALVAC-SIV Vaccine-Primed Macaques with the CD4-SIVgp120 Fusion Protein Elicits Antibodies to V2 Associated with a Decreased Risk of SIVmac251 Acquisition. THE JOURNAL OF IMMUNOLOGY 2016; 197:2726-37. [PMID: 27591322 DOI: 10.4049/jimmunol.1600674] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 08/04/2016] [Indexed: 11/19/2022]
Abstract
The recombinant ALVAC vaccine coupled with the monomeric gp120/alum protein have decreased the risk of HIV and SIV acquisition. Ab responses to the V1/V2 regions have correlated with a decreased risk of virus acquisition in both humans and macaques. We hypothesized that the breadth and functional profile of Abs induced by an ALVAC/envelope protein regimen could be improved by substituting the monomeric gp120 boost, with the full-length single-chain (FLSC) protein. FLSC is a CD4-gp120 fusion immunogen that exposes cryptic gp120 epitopes to the immune system. We compared the immunogenicity and relative efficiency of an ALVAC-SIV vaccine boosted either with bivalent FLSC proteins or with monomeric gp120 in alum. FLSC was superior to monomeric gp120 in directing Abs to the C3 α2 helix, the V5 loop, and the V3 region that contains the putative CCR5 binding site. In addition, FLSC boosting elicited significantly higher binding Abs to V2 and increased both the Ab-dependent cellular cytotoxicity activity and the breadth of neutralizing Abs. However, the FLSC vaccine regimen demonstrated only a trend in vaccine efficacy, whereas the monomeric gp120 regimen significantly decreased the risk of SIVmac251 acquisition. In both vaccine regimens, anti-V2 Abs correlated with a decreased risk of virus acquisition but differed with regard to systemic or mucosal origin. In the FLSC regimen, serum Abs to V2 correlated, whereas in the monomeric gp120 regimen, V2 Abs in rectal secretions, the site of viral challenge, were associated with efficacy.
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Affiliation(s)
- Shari N Gordon
- Animal Models and Vaccine Section, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Namal P M Liyanage
- Animal Models and Vaccine Section, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Melvin N Doster
- Animal Models and Vaccine Section, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Monica Vaccari
- Animal Models and Vaccine Section, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Diego A Vargas-Inchaustegui
- Immune Biology of Retroviral Infection Section, Vaccine Branch, National Cancer Institute, Bethesda, MD 20892
| | - Poonam Pegu
- Animal Models and Vaccine Section, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Luca Schifanella
- Animal Models and Vaccine Section, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | | | | | - Mangala Rao
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD 20910
| | - Erik A Billings
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD 20910
| | | | - Ilia Prado
- Profectus BioSciences Inc., Baltimore, MD 21224
| | | | | | | | - Kathryn E Foulds
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | | | - Marjorie Robert-Guroff
- Immune Biology of Retroviral Infection Section, Vaccine Branch, National Cancer Institute, Bethesda, MD 20892
| | - Mario Roederer
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Tran B Phan
- Division of Infectious Diseases, Department of Medicine, University of California, Irvine School of Medicine, Irvine, CA 92868
| | - Donald N Forthal
- Division of Infectious Diseases, Department of Medicine, University of California, Irvine School of Medicine, Irvine, CA 92868
| | | | | | - David J Venzon
- Biostatistics and Data Management Section, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | | | - Genoveffa Franchini
- Animal Models and Vaccine Section, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892;
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9
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Swanstrom AE, Haggarty B, Jordan APO, Romano J, Leslie GJ, Aye PP, Marx PA, Lackner AA, Del Prete GQ, Robinson JE, Betts MR, Montefiori DC, LaBranche CC, Hoxie JA. Derivation and Characterization of a CD4-Independent, Non-CD4-Tropic Simian Immunodeficiency Virus. J Virol 2016; 90:4966-4980. [PMID: 26937037 PMCID: PMC4859711 DOI: 10.1128/jvi.02851-15] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Accepted: 02/24/2016] [Indexed: 12/16/2022] Open
Abstract
UNLABELLED CD4 tropism is conserved among all primate lentiviruses and likely contributes to viral pathogenesis by targeting cells that are critical for adaptive antiviral immune responses. Although CD4-independent variants of human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) have been described that can utilize the coreceptor CCR5 or CXCR4 in the absence of CD4, these viruses typically retain their CD4 binding sites and still can interact with CD4. We describe the derivation of a novel CD4-independent variant of pathogenic SIVmac239, termed iMac239, that was used to derive an infectious R5-tropic SIV lacking a CD4 binding site. Of the seven mutations that differentiate iMac239 from wild-type SIVmac239, a single change (D178G) in the V1/V2 region was sufficient to confer CD4 independence in cell-cell fusion assays, although other mutations were required for replication competence. Like other CD4-independent viruses, iMac239 was highly neutralization sensitive, although mutations were identified that could confer CD4-independent infection without increasing its neutralization sensitivity. Strikingly, iMac239 retained the ability to replicate in cell lines and primary cells even when its CD4 binding site had been ablated by deletion of a highly conserved aspartic acid at position 385, which, for HIV-1, plays a critical role in CD4 binding. iMac239, with and without the D385 deletion, exhibited an expanded host range in primary rhesus peripheral blood mononuclear cells that included CCR5(+) CD8(+) T cells. As the first non-CD4-tropic SIV, iMac239-ΔD385 will afford the opportunity to directly assess the in vivo role of CD4 targeting on pathogenesis and host immune responses. IMPORTANCE CD4 tropism is an invariant feature of primate lentiviruses and likely plays a key role in pathogenesis by focusing viral infection onto cells that mediate adaptive immune responses and in protecting virions attached to cells from neutralizing antibodies. Although CD4-independent viruses are well described for HIV and SIV, these viruses characteristically retain their CD4 binding site and can engage CD4 if available. We derived a novel CD4-independent, CCR5-tropic variant of the pathogenic molecular clone SIVmac239, termed iMac239. The genetic determinants of iMac239's CD4 independence provide new insights into mechanisms that underlie this phenotype. This virus remained replication competent even after its CD4 binding site had been ablated by mutagenesis. As the first truly non-CD4-tropic SIV, lacking the capacity to interact with CD4, iMac239 will provide the unique opportunity to evaluate SIV pathogenesis and host immune responses in the absence of the immunomodulatory effects of CD4(+) T cell targeting and infection.
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Affiliation(s)
- Adrienne E Swanstrom
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Beth Haggarty
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Andrea P O Jordan
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Josephine Romano
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - George J Leslie
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Pyone P Aye
- Tulane National Primate Research Center, Covington, and Department of Tropical Medicine, Tulane University, New Orleans, Louisiana, USA
| | - Preston A Marx
- Tulane National Primate Research Center, Covington, and Department of Tropical Medicine, Tulane University, New Orleans, Louisiana, USA
| | - Andrew A Lackner
- Tulane National Primate Research Center, Covington, and Department of Tropical Medicine, Tulane University, New Orleans, Louisiana, USA
| | - Gregory Q Del Prete
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA
| | - James E Robinson
- Department of Pediatrics, Tulane University School of Medicine, New Orleans, Louisiana, USA
| | - Michael R Betts
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - David C Montefiori
- Department of Surgery, Duke University Medical Center, Durham, North Carolina, USA
| | - Celia C LaBranche
- Department of Surgery, Duke University Medical Center, Durham, North Carolina, USA
| | - James A Hoxie
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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10
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Lin N, Gonzalez OA, Registre L, Becerril C, Etemad B, Lu H, Wu X, Lockman S, Essex M, Moyo S, Kuritzkes DR, Sagar M. Humoral Immune Pressure Selects for HIV-1 CXC-chemokine Receptor 4-using Variants. EBioMedicine 2016; 8:237-247. [PMID: 27428434 PMCID: PMC4919596 DOI: 10.1016/j.ebiom.2016.04.040] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 04/26/2016] [Accepted: 04/27/2016] [Indexed: 11/26/2022] Open
Abstract
Although both C-C chemokine receptor 5 (CCR5)- and CXC chemokine receptor 4 (CXCR4)-using HIV-1 strains cause AIDS, the emergence of CXCR4-utilizing variants is associated with an accelerated decline in CD4+ T cells. It remains uncertain if CXCR4-using viruses hasten disease or if these variants only emerge after profound immunological damage. We show that exclusively CXCR4- as compared to cocirculating CCR5-utilizing variants are less sensitive to neutralization by both contemporaneous autologous plasma and plasma pools from individuals that harbor only CCR5-using HIV-1. The CXCR4-utilizing variants, however, do not have a global antigenic change because they remain equivalently susceptible to antibodies that do not target coreceptor binding domains. Studies with envelope V3 loop directed antibodies and chimeric envelopes suggest that the neutralization susceptibility differences are potentially influenced by the V3 loop. In vitro passage of a neutralization sensitive CCR5-using virus in the presence of autologous plasma and activated CD4+ T cells led to the emergence of a CXCR4-utilizing virus in 1 of 3 cases. These results suggest that in some but not necessarily all HIV-1 infected individuals humoral immune pressure against the autologous virus selects for CXCR4-using variants, which potentially accelerates disease progression. Our observations have implications for using antibodies for HIV-1 immune therapy.
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Affiliation(s)
- Nina Lin
- Section of Infectious Diseases, Department of Medicine, Boston University School of Medicine, Boston, MA, United States
| | - Oscar A Gonzalez
- Section of Infectious Diseases, Department of Medicine, Boston University School of Medicine, Boston, MA, United States
| | - Ludy Registre
- Section of Infectious Diseases, Department of Medicine, Boston University School of Medicine, Boston, MA, United States
| | - Carlos Becerril
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, MA, United States
| | - Behzad Etemad
- Section of Infectious Diseases, Department of Medicine, Boston University School of Medicine, Boston, MA, United States
| | - Hong Lu
- Aaron Diamond AIDS Research Center, New York, NY, United States
| | - Xueling Wu
- Aaron Diamond AIDS Research Center, New York, NY, United States
| | - Shahin Lockman
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, MA, United States; Harvard School of Public Health, Boston, MA, United States; Harvard Medical School, Boston, MA, United States
| | - Myron Essex
- Harvard School of Public Health, Boston, MA, United States; Botswana Harvard AIDS Institute, Gaborone, Botswana
| | | | - Daniel R Kuritzkes
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, MA, United States; Harvard Medical School, Boston, MA, United States
| | - Manish Sagar
- Section of Infectious Diseases, Department of Medicine, Boston University School of Medicine, Boston, MA, United States.
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11
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Pan Y, Xiao L, Li ASS, Zhang X, Sirois P, Zhang J, Li K. Biological and biomedical applications of engineered nucleases. Mol Biotechnol 2014; 55:54-62. [PMID: 23089945 DOI: 10.1007/s12033-012-9613-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The development of engineered nucleases is the fruit of a new technological approach developed in the last two decades which has led to significant benefits on genome engineering, particularly on gene therapy. These applications enable efficient and specific genetic modifications via the induction of a double-strand break (DSB) in a specific genomic target sequence, followed by the homology-directed repair (HDR) or non-homologous end joining (NHEJ) pathways. In addition to the application on gene modification in cells and intact organisms, a number of recent papers have reported that this gene editing technology can be applied effectively to human diseases. With the promising data obtained using engineered endonucleases in gene therapy, it appears reasonable to expect that more diseases could be treated and even be cured in this new era of individualized medicine. This paper first brief introduces the development of engineered nucleases with a special emphasis on zinc-finger nucleases (ZFNs) and transcription activator-like effector (TALE) nucleases (TALENs), and then takes CCR5-based gene therapy as an example to discuss the therapeutic applications of engineered nucleases.
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Affiliation(s)
- Yunzhi Pan
- Department of Molecular Diagnostics and Biopharmaceutics, College of Pharmaceutical Science, Soochow University, Suzhou 215123, China
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12
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Roederer M, Keele BF, Schmidt SD, Mason RD, Welles HC, Fischer W, Labranche C, Foulds KE, Louder MK, Yang ZY, Todd JPM, Buzby AP, Mach LV, Shen L, Seaton KE, Ward BM, Bailer RT, Gottardo R, Gu W, Ferrari G, Alam SM, Denny TN, Montefiori DC, Tomaras GD, Korber BT, Nason MC, Seder RA, Koup RA, Letvin NL, Rao SS, Nabel GJ, Mascola JR. Immunological and virological mechanisms of vaccine-mediated protection against SIV and HIV. Nature 2014; 505:502-8. [PMID: 24352234 PMCID: PMC3946913 DOI: 10.1038/nature12893] [Citation(s) in RCA: 126] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 11/21/2013] [Indexed: 02/07/2023]
Abstract
A major challenge for the development of a highly effective AIDS vaccine is the identification of mechanisms of protective immunity. To address this question, we used a nonhuman primate challenge model with simian immunodeficiency virus (SIV). We show that antibodies to the SIV envelope are necessary and sufficient to prevent infection. Moreover, sequencing of viruses from breakthrough infections revealed selective pressure against neutralization-sensitive viruses; we identified a two-amino-acid signature that alters antigenicity and confers neutralization resistance. A similar signature confers resistance of human immunodeficiency virus (HIV)-1 to neutralization by monoclonal antibodies against variable regions 1 and 2 (V1V2), suggesting that SIV and HIV share a fundamental mechanism of immune escape from vaccine-elicited or naturally elicited antibodies. These analyses provide insight into the limited efficacy seen in HIV vaccine trials.
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Affiliation(s)
- Mario Roederer
- Vaccine Research Center, NIAID, NIH, Bethesda, Maryland 20892, USA
| | - Brandon F Keele
- SAIC-Frederick, Frederick National Laboratory, NIH, Frederick, Maryland 21702, USA
| | | | | | - Hugh C Welles
- 1] Vaccine Research Center, NIAID, NIH, Bethesda, Maryland 20892, USA [2] George Washington University, Washington DC 20052, USA
| | - Will Fischer
- Los Alamos National Laboratories, Los Alamos, New Mexico 87545, USA
| | - Celia Labranche
- Department of Surgery, Duke University, Durham, North Carolina 27710, USA
| | - Kathryn E Foulds
- Vaccine Research Center, NIAID, NIH, Bethesda, Maryland 20892, USA
| | - Mark K Louder
- Vaccine Research Center, NIAID, NIH, Bethesda, Maryland 20892, USA
| | - Zhi-Yong Yang
- 1] Vaccine Research Center, NIAID, NIH, Bethesda, Maryland 20892, USA [2] Sanofi-Pasteur, Cambridge, Massachusetts 02139, USA
| | - John-Paul M Todd
- Vaccine Research Center, NIAID, NIH, Bethesda, Maryland 20892, USA
| | - Adam P Buzby
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02115, USA
| | - Linh V Mach
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02115, USA
| | - Ling Shen
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02115, USA
| | - Kelly E Seaton
- Human Vaccine Institute, Duke University, Durham, North Carolina 27710, USA
| | - Brandy M Ward
- Department of Surgery, Duke University, Durham, North Carolina 27710, USA
| | - Robert T Bailer
- Vaccine Research Center, NIAID, NIH, Bethesda, Maryland 20892, USA
| | - Raphael Gottardo
- Fred Hutchison Cancer Research Center, Seattle, Washington 98109, USA
| | - Wenjuan Gu
- Biostatistics Research Branch, NIAID, NIH, Bethesda, Maryland 20892, USA
| | - Guido Ferrari
- Department of Surgery, Duke University, Durham, North Carolina 27710, USA
| | - S Munir Alam
- Human Vaccine Institute, Duke University, Durham, North Carolina 27710, USA
| | - Thomas N Denny
- Human Vaccine Institute, Duke University, Durham, North Carolina 27710, USA
| | - David C Montefiori
- Department of Surgery, Duke University, Durham, North Carolina 27710, USA
| | - Georgia D Tomaras
- Human Vaccine Institute, Duke University, Durham, North Carolina 27710, USA
| | - Bette T Korber
- Los Alamos National Laboratories, Los Alamos, New Mexico 87545, USA
| | - Martha C Nason
- Biostatistics Research Branch, NIAID, NIH, Bethesda, Maryland 20892, USA
| | - Robert A Seder
- Vaccine Research Center, NIAID, NIH, Bethesda, Maryland 20892, USA
| | - Richard A Koup
- Vaccine Research Center, NIAID, NIH, Bethesda, Maryland 20892, USA
| | - Norman L Letvin
- 1] Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02115, USA [2]
| | - Srinivas S Rao
- Vaccine Research Center, NIAID, NIH, Bethesda, Maryland 20892, USA
| | - Gary J Nabel
- 1] Vaccine Research Center, NIAID, NIH, Bethesda, Maryland 20892, USA [2] Sanofi-Pasteur, Cambridge, Massachusetts 02139, USA
| | - John R Mascola
- Vaccine Research Center, NIAID, NIH, Bethesda, Maryland 20892, USA
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13
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Quantification of entry phenotypes of macrophage-tropic HIV-1 across a wide range of CD4 densities. J Virol 2013; 88:1858-69. [PMID: 24307580 DOI: 10.1128/jvi.02477-13] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Defining a macrophage-tropic phenotype for HIV-1 to assess a role in pathogenesis is complicated by the fact that HIV-1 isolates vary continuously in their ability to enter monocyte-derived macrophages (MDMs) in vitro, and MDMs vary in their ability to support HIV-1 entry. To overcome these limitations, we identified consistent differences in entry phenotypes between five paired blood-derived, T cell-tropic HIV-1 env genes, four of which are CCR5-using (R5) and one of which is CXCR4-using (X4), and cerebrospinal fluid (CSF)-derived, R5 macrophage-tropic env genes. We performed entry assays using the CD4- and CCR5-inducible Affinofile cell line, expressing a range of CD4 levels that approximates the range from MDMs to CD4(+) T cells. The macrophage-tropic viruses were significantly better at infecting cells expressing low levels of CD4 than the T cell-tropic viruses from the same subjects, with the titration of CD4 providing a distinctive and quantitative phenotype. This difference in CD4 utilization was not due to macrophage-tropic viruses being CD4 independent. Furthermore, macrophage-tropic viruses did not differ from paired T cell-tropic viruses in their ability to use low levels of CCR5 (tpaired = -1.39; P = 0.24) or their use of an alternative conformation of CCR5. We also infected MDMs with a panel of viruses and observed that infectivity of each virus differed across four donors and between three preparations from a single donor. We concluded that the evolutionary transition from replication in T cells to that in macrophages involves a phenotypic transition to acquire the ability to infect cells expressing low levels of CD4 and that this phenotype is more reliably measured in Affinofile cells than in macrophages. IMPORTANCE HIV-1 typically infects memory T cells by using CD4 and CCR5 to enter cells. The virus evolves to infect new cell types by changing the coreceptor from CCR5 to CXCR4 to infect naive T cells or adapting to the use of low levels of CD4 to infect macrophages. However, defining the phenotype of macrophage tropism has been difficult due to inherent variability in the use of macrophages generated in culture to support entry of HIV-1. We describe the use of Affinofile cells with inducible and variable levels of CD4 to identify a signature phenotype for macrophage-tropic HIV-1. The ability to define HIV-1 variants that have evolved an entry phenotype that allows more efficient entry into cells with low levels of CD4 sets the stage for a clearer placement of these variants in HIV-associated pathogenesis.
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14
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Kiene M, Marzi A, Urbanczyk A, Bertram S, Fisch T, Nehlmeier I, Gnirß K, Karsten CB, Palesch D, Münch J, Chiodi F, Pöhlmann S, Steffen I. The role of the alternative coreceptor GPR15 in SIV tropism for human cells. Virology 2012; 433:73-84. [DOI: 10.1016/j.virol.2012.07.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 04/25/2012] [Accepted: 07/13/2012] [Indexed: 10/28/2022]
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15
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Iyengar S, Schwartz DH. Acquisition of CD4-dependence by CD4-independent SIV passaged in human peripheral blood mononuclear cells. Retrovirology 2012; 9:61. [PMID: 22830620 PMCID: PMC3418575 DOI: 10.1186/1742-4690-9-61] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Accepted: 07/25/2012] [Indexed: 11/18/2022] Open
Abstract
Background Chemokine receptors (CKRs), the primordial receptors for primate lentiviruses, are sufficient to mediate virus-cell fusion. Several different fusogenic CKRs and related receptors provide a broad potential host cell range, presumably advantageous for viral spread within a given infected individual, and across species. By contrast, the additional constraint of obligatory CD4 binding, just prior to CKR engagement, radically restricts potential host cells within an individual (or lymph node microenvironment), and might also limit xenotransmission, as CD4 sequences vary among primates. In spite of these potential drawbacks, CD4 dependent entry for SIV and HIV is the rule rather than the exception, and is generally thought to have evolved by selection for 1) stabilization of virus–cell surface interactions, and 2) conformational shielding of readily neutralized CKR binding epitopes. CD4 binding residues of SIV and HIV envelope are recessed, (relatively hidden from immune detection) and may exhibit a strong degree of automimicry, thus benefitting from self tolerance. Documented evolution, within individual macaques, of neutralization-resistant CD4-dependent SIV, derived from CD4-independent inocula, supports these ideas, but does not explain CD4’s exclusive role as the penultimate receptor-even more striking, given the wide diversity of CKRs and other surface molecules that can serve as actual fusion receptors for SIV. We, therefore, explored the additional, non-exclusive, hypothesis that surface CD4 on leukocytes is a marker of a more favorable host cell environment, as compared to CD8, NK, or B cell surface markers. Results We demonstrate progressive in vitro evolution of two SIV strains to CD4-dependence (and CXCR4 tropism) in normal human PBMCs (hPBMCs). The two CD4-independent strains of SIV tested developed nearly complete CD4 dependence over several months of serial passage in hPBMCs, correlating with a limited number of non-synonymous env region mutations, some previously reported to be determinants of CD4-dependency. The initial ability of SIV stocks to grow to significant (albeit, relatively low) levels in CD4(−), CD14(−) cells was also lost with long term passage. Rapid emergence and subsequent prominence of G → A and A → G mutations within env regions associated with CD4 dependence was seen. Conclusions Progressive acquisition of strict CD4 tropism, independent of immunoselection, supports the idea that surface CD4 identifies optimal host cells having intracellular environments most favorable to viral replication. The prominence of mutations involving G to A, or A to G, suggests that APOBEC 3 mediated infidelity may facilitate rapid switching of cell surface receptor usage within SIV swarms encountering fluctuating availability of optimal CD4+CKR+ targets. These observations of non-immune selection are compatible with, and may accelerate, simultaneous selection for previously described CD4-dependent neutralization resistance in vivo.
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Affiliation(s)
- Sujatha Iyengar
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, USA
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16
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Xiao A, Hu YY, Wang WY, Yang ZP, Wang ZX, Huang P, Tong XJ, Zhang B, Lin S. [Progress in zinc finger nuclease engineering for targeted genome modification]. YI CHUAN = HEREDITAS 2011; 33:665-83. [PMID: 22049679 DOI: 10.3724/sp.j.1005.2011.00665] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Zinc finger nuclease (ZFN) is an artificially engineered hybrid protein that contains a zinc finger protein (ZFP) domain and a Fok I endonuclease cleavage domain. It has recently emerged as a powerful molecular tool for targeted genome modifications. ZFNs recognize and bind to specific DNA sequences to generate a double-strand break (DSB) by its nuclease activity. Based on this finding, various genetic methods, including gene targeting (gene disruption), gene addition, gene correction etc., are being designed to manipulate the genomes of different species at specific loci. One particular advantage of this new technique is its broad applications, which can be employed to generate desirable inheritable mutations both at the organismal level and at the cellular level. Here, we review the recent progress and prospects of ZFN technology. This article focused on the mechanism of how it works, currently available target assessment, ZFP library construction and screening methods, target modification strategies, as well as a collection of specie and genes that have been successfully modified by ZFN. This review will provide a useful reference for researchers who are interested in applying this new technique in their studies.
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Affiliation(s)
- An Xiao
- Key Laboratory of Cell Proliferation and Differentiation of Ministry of Education, College of Life Sciences, Peking University, Beijing 100871, China.
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17
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Minang JT, Trivett MT, Barsov EV, Del Prete GQ, Trubey CM, Thomas JA, Gorelick RJ, Piatak M, Ott DE, Ohlen C. TCR triggering transcriptionally downregulates CCR5 expression on rhesus macaque CD4(+) T-cells with no measurable effect on susceptibility to SIV infection. Virology 2011; 409:132-40. [PMID: 21035160 PMCID: PMC3001627 DOI: 10.1016/j.virol.2010.10.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Revised: 09/28/2010] [Accepted: 10/03/2010] [Indexed: 12/24/2022]
Abstract
Studies using transformed human cell lines suggest that most SIV strains use CCR5 as co-receptor. Our analysis of primary rhesus macaque CD4(+) T-cell clones revealed marked differences in susceptibility to SIV(mac)239 infection. We investigated whether different levels of CCR5 expression account for clonal differences in SIV(mac)239 susceptibility. Macaque CD4(+) T-cells showed significant CCR5 downregulation 1-2days following CD3 mAb stimulation, which gradually recovered at resting state, 7-10days after activation. Exposure of clones to SIV(mac)239 during their CCR5(low) or CCR5(high) expression states revealed differences in SIV susceptibility independent of surface CCR5 levels. Furthermore, a CCR5 antagonist similarly reduced SIV(mac)239 infection of clones during their CCR5(low) or CCR5(high) expression states. Our data suggest a model where i) very low levels of CCR5 are sufficient for efficient SIV infection, ii) CCR5 levels above this threshold do not enhance infection, and iii) low level infection can occur in the absence of CCR5.
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MESH Headings
- Animals
- Antibodies, Monoclonal/immunology
- Antibodies, Monoclonal/metabolism
- CCR5 Receptor Antagonists
- CD3 Complex/immunology
- CD3 Complex/metabolism
- CD4-Positive T-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/metabolism
- CD4-Positive T-Lymphocytes/virology
- Cell Line
- DNA, Viral/analysis
- Down-Regulation
- Female
- Gene Products, gag/genetics
- Gene Products, gag/immunology
- Gene Products, gag/metabolism
- Humans
- Macaca mulatta
- Male
- Receptors, Antigen, T-Cell/genetics
- Receptors, Antigen, T-Cell/immunology
- Receptors, Antigen, T-Cell/metabolism
- Receptors, CCR5/genetics
- Receptors, CCR5/metabolism
- Simian Acquired Immunodeficiency Syndrome/immunology
- Simian Acquired Immunodeficiency Syndrome/virology
- Simian Immunodeficiency Virus/pathogenicity
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Affiliation(s)
- Jacob T. Minang
- AIDS and Cancer Virus Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, USA
| | - Matthew T. Trivett
- AIDS and Cancer Virus Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, USA
| | - Eugene V Barsov
- AIDS and Cancer Virus Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, USA
| | - Gregory Q. Del Prete
- AIDS and Cancer Virus Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, USA
| | - Charles M. Trubey
- AIDS and Cancer Virus Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, USA
| | - James A. Thomas
- AIDS and Cancer Virus Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, USA
| | - Robert J. Gorelick
- AIDS and Cancer Virus Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, USA
| | - Michael Piatak
- AIDS and Cancer Virus Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, USA
| | - David E. Ott
- AIDS and Cancer Virus Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, USA
| | - Claes Ohlen
- AIDS and Cancer Virus Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, USA
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18
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Doyon Y, Vo TD, Mendel MC, Greenberg SG, Wang J, Xia DF, Miller JC, Urnov FD, Gregory PD, Holmes MC. Enhancing zinc-finger-nuclease activity with improved obligate heterodimeric architectures. Nat Methods 2010; 8:74-9. [PMID: 21131970 DOI: 10.1038/nmeth.1539] [Citation(s) in RCA: 305] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Accepted: 11/05/2010] [Indexed: 11/09/2022]
Abstract
Zinc-finger nucleases (ZFNs) drive efficient genome editing by introducing a double-strand break into the targeted gene. Cleavage is induced when two custom-designed ZFNs heterodimerize upon binding DNA to form a catalytically active nuclease complex. The importance of this dimerization event for subsequent cleavage activity has stimulated efforts to engineer the nuclease interface to prevent undesired homodimerization. Here we report the development and application of a yeast-based selection system designed to functionally interrogate the ZFN dimer interface. We identified critical residues involved in dimerization through the isolation of cold-sensitive nuclease domains. We used these residues to engineer ZFNs that have superior cleavage activity while suppressing homodimerization. The improvements were portable to orthogonal domains, allowing the concomitant and independent cleavage of two loci using two different ZFN pairs. These ZFN architectures provide a general means for obtaining highly efficient and specific genome modification.
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19
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Alpert MD, Rahmberg AR, Neidermyer W, Ng SK, Carville A, Camp JV, Wilson RL, Piatak M, Mansfield KG, Li W, Miller CJ, Lifson JD, Kozlowski PA, Evans DT. Envelope-modified single-cycle simian immunodeficiency virus selectively enhances antibody responses and partially protects against repeated, low-dose vaginal challenge. J Virol 2010; 84:10748-64. [PMID: 20702641 PMCID: PMC2950576 DOI: 10.1128/jvi.00945-10] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Accepted: 07/29/2010] [Indexed: 11/20/2022] Open
Abstract
Immunization of rhesus macaques with strains of simian immunodeficiency virus (SIV) that are limited to a single cycle of infection elicits T-cell responses to multiple viral gene products and antibodies capable of neutralizing lab-adapted SIV, but not neutralization-resistant primary isolates of SIV. In an effort to improve upon the antibody responses, we immunized rhesus macaques with three strains of single-cycle SIV (scSIV) that express envelope glycoproteins modified to lack structural features thought to interfere with the development of neutralizing antibodies. These envelope-modified strains of scSIV lacked either five potential N-linked glycosylation sites in gp120, three potential N-linked glycosylation sites in gp41, or 100 amino acids in the V1V2 region of gp120. Three doses consisting of a mixture of the three envelope-modified strains of scSIV were administered on weeks 0, 6, and 12, followed by two booster inoculations with vesicular stomatitis virus (VSV) G trans-complemented scSIV on weeks 18 and 24. Although this immunization regimen did not elicit antibodies capable of detectably neutralizing SIV(mac)239 or SIV(mac)251(UCD), neutralizing antibody titers to the envelope-modified strains were selectively enhanced. Virus-specific antibodies and T cells were observed in the vaginal mucosa. After 20 weeks of repeated, low-dose vaginal challenge with SIV(mac)251(UCD), six of eight immunized animals versus six of six naïve controls became infected. Although immunization did not significantly reduce the likelihood of acquiring immunodeficiency virus infection, statistically significant reductions in peak and set point viral loads were observed in the immunized animals relative to the naïve control animals.
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Affiliation(s)
- Michael D. Alpert
- Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772-9102, Department of Pathology, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772-9102, Gene Therapy Program and Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, SAIC—Frederick, National Cancer Institute at Frederick, Frederick, Maryland 21702, University of Massachusetts, Worcester, Massachusetts 01655, California National Primate Research Center, University of California, Davis, California 95616
| | - Andrew R. Rahmberg
- Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772-9102, Department of Pathology, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772-9102, Gene Therapy Program and Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, SAIC—Frederick, National Cancer Institute at Frederick, Frederick, Maryland 21702, University of Massachusetts, Worcester, Massachusetts 01655, California National Primate Research Center, University of California, Davis, California 95616
| | - William Neidermyer
- Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772-9102, Department of Pathology, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772-9102, Gene Therapy Program and Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, SAIC—Frederick, National Cancer Institute at Frederick, Frederick, Maryland 21702, University of Massachusetts, Worcester, Massachusetts 01655, California National Primate Research Center, University of California, Davis, California 95616
| | - Sharon K. Ng
- Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772-9102, Department of Pathology, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772-9102, Gene Therapy Program and Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, SAIC—Frederick, National Cancer Institute at Frederick, Frederick, Maryland 21702, University of Massachusetts, Worcester, Massachusetts 01655, California National Primate Research Center, University of California, Davis, California 95616
| | - Angela Carville
- Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772-9102, Department of Pathology, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772-9102, Gene Therapy Program and Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, SAIC—Frederick, National Cancer Institute at Frederick, Frederick, Maryland 21702, University of Massachusetts, Worcester, Massachusetts 01655, California National Primate Research Center, University of California, Davis, California 95616
| | - Jeremy V. Camp
- Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772-9102, Department of Pathology, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772-9102, Gene Therapy Program and Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, SAIC—Frederick, National Cancer Institute at Frederick, Frederick, Maryland 21702, University of Massachusetts, Worcester, Massachusetts 01655, California National Primate Research Center, University of California, Davis, California 95616
| | - Robert L. Wilson
- Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772-9102, Department of Pathology, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772-9102, Gene Therapy Program and Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, SAIC—Frederick, National Cancer Institute at Frederick, Frederick, Maryland 21702, University of Massachusetts, Worcester, Massachusetts 01655, California National Primate Research Center, University of California, Davis, California 95616
| | - Michael Piatak
- Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772-9102, Department of Pathology, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772-9102, Gene Therapy Program and Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, SAIC—Frederick, National Cancer Institute at Frederick, Frederick, Maryland 21702, University of Massachusetts, Worcester, Massachusetts 01655, California National Primate Research Center, University of California, Davis, California 95616
| | - Keith G. Mansfield
- Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772-9102, Department of Pathology, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772-9102, Gene Therapy Program and Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, SAIC—Frederick, National Cancer Institute at Frederick, Frederick, Maryland 21702, University of Massachusetts, Worcester, Massachusetts 01655, California National Primate Research Center, University of California, Davis, California 95616
| | - Wenjun Li
- Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772-9102, Department of Pathology, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772-9102, Gene Therapy Program and Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, SAIC—Frederick, National Cancer Institute at Frederick, Frederick, Maryland 21702, University of Massachusetts, Worcester, Massachusetts 01655, California National Primate Research Center, University of California, Davis, California 95616
| | - Christopher J. Miller
- Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772-9102, Department of Pathology, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772-9102, Gene Therapy Program and Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, SAIC—Frederick, National Cancer Institute at Frederick, Frederick, Maryland 21702, University of Massachusetts, Worcester, Massachusetts 01655, California National Primate Research Center, University of California, Davis, California 95616
| | - Jeffrey D. Lifson
- Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772-9102, Department of Pathology, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772-9102, Gene Therapy Program and Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, SAIC—Frederick, National Cancer Institute at Frederick, Frederick, Maryland 21702, University of Massachusetts, Worcester, Massachusetts 01655, California National Primate Research Center, University of California, Davis, California 95616
| | - Pamela A. Kozlowski
- Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772-9102, Department of Pathology, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772-9102, Gene Therapy Program and Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, SAIC—Frederick, National Cancer Institute at Frederick, Frederick, Maryland 21702, University of Massachusetts, Worcester, Massachusetts 01655, California National Primate Research Center, University of California, Davis, California 95616
| | - David T. Evans
- Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772-9102, Department of Pathology, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772-9102, Gene Therapy Program and Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, SAIC—Frederick, National Cancer Institute at Frederick, Frederick, Maryland 21702, University of Massachusetts, Worcester, Massachusetts 01655, California National Primate Research Center, University of California, Davis, California 95616
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Urnov FD, Rebar EJ, Holmes MC, Zhang HS, Gregory PD. Genome editing with engineered zinc finger nucleases. Nat Rev Genet 2010; 11:636-46. [PMID: 20717154 DOI: 10.1038/nrg2842] [Citation(s) in RCA: 1424] [Impact Index Per Article: 101.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Reverse genetics in model organisms such as Drosophila melanogaster, Arabidopsis thaliana, zebrafish and rats, efficient genome engineering in human embryonic stem and induced pluripotent stem cells, targeted integration in crop plants, and HIV resistance in immune cells - this broad range of outcomes has resulted from the application of the same core technology: targeted genome cleavage by engineered, sequence-specific zinc finger nucleases followed by gene modification during subsequent repair. Such 'genome editing' is now established in human cells and a number of model organisms, thus opening the door to a range of new experimental and therapeutic possibilities.
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Affiliation(s)
- Fyodor D Urnov
- Sangamo BioSciences Inc., Richmond, California 94804, USA
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21
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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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