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Nunberg JH, Westover JB, York J, Jung KH, Bailey KW, Boardman KM, Li M, Furnell RS, Wasson SR, Murray JS, Kaundal R, Thomas AJ, Gowen BB. Restoration of virulence in the attenuated Candid#1 vaccine virus requires reversion at both positions 168 and 427 in the envelope glycoprotein GPC. J Virol 2024; 98:e0011224. [PMID: 38506509 PMCID: PMC11019782 DOI: 10.1128/jvi.00112-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Accepted: 02/29/2024] [Indexed: 03/21/2024] Open
Abstract
Live-attenuated virus vaccines provide long-lived protection against viral disease but carry inherent risks of residual pathogenicity and genetic reversion. The live-attenuated Candid#1 vaccine was developed to protect Argentines against lethal infection by the Argentine hemorrhagic fever arenavirus, Junín virus. Despite its safety and efficacy in Phase III clinical study, the vaccine is not licensed in the US, in part due to concerns regarding the genetic stability of attenuation. Previous studies had identified a single F427I mutation in the transmembrane domain of the Candid#1 envelope glycoprotein GPC as the key determinant of attenuation, as well as the propensity of this mutation to revert upon passage in cell culture and neonatal mice. To ascertain the consequences of this reversion event, we introduced the I427F mutation into recombinant Candid#1 (I427F rCan) and investigated the effects in two validated small-animal models: in mice expressing the essential virus receptor (human transferrin receptor 1; huTfR1) and in the conventional guinea pig model. We report that I427F rCan displays only modest virulence in huTfR1 mice and appears attenuated in guinea pigs. Reversion at another attenuating locus in Candid#1 GPC (T168A) was also examined, and a similar pattern was observed. By contrast, virus bearing both revertant mutations (A168T+I427F rCan) approached the lethal virulence of the pathogenic Romero strain in huTfR1 mice. Virulence was less extreme in guinea pigs. Our findings suggest that genetic stabilization at both positions is required to minimize the likelihood of reversion to virulence in a second-generation Candid#1 vaccine.IMPORTANCELive-attenuated virus vaccines, such as measles/mumps/rubella and oral poliovirus, provide robust protection against disease but carry with them the risk of genetic reversion to the virulent form. Here, we analyze the genetics of reversion in the live-attenuated Candid#1 vaccine that is used to protect against Argentine hemorrhagic fever, an often-lethal disease caused by the Junín arenavirus. In two validated small-animal models, we find that restoration of virulence in recombinant Candid#1 viruses requires back-mutation at two positions specific to the Candid#1 envelope glycoprotein GPC, at positions 168 and 427. Viruses bearing only a single change showed only modest virulence. We discuss strategies to genetically harden Candid#1 GPC against these two reversion events in order to develop a safer second-generation Candid#1 vaccine virus.
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Affiliation(s)
- Jack H. Nunberg
- Montana Biotechnology Center, University of Montana, Missoula, Montana, USA
| | - Jonna B. Westover
- Department of Animal Dairy and Veterinary Sciences, Utah State University, Logan, Utah, USA
- Institute for Antiviral Research, Utah State University, Logan, Utah, USA
| | - Joanne York
- Montana Biotechnology Center, University of Montana, Missoula, Montana, USA
| | - Kie Hoon Jung
- Department of Animal Dairy and Veterinary Sciences, Utah State University, Logan, Utah, USA
- Institute for Antiviral Research, Utah State University, Logan, Utah, USA
| | - Kevin W. Bailey
- Department of Animal Dairy and Veterinary Sciences, Utah State University, Logan, Utah, USA
- Institute for Antiviral Research, Utah State University, Logan, Utah, USA
| | - Kirsten M. Boardman
- Department of Animal Dairy and Veterinary Sciences, Utah State University, Logan, Utah, USA
- Institute for Antiviral Research, Utah State University, Logan, Utah, USA
| | - Minghao Li
- Department of Animal Dairy and Veterinary Sciences, Utah State University, Logan, Utah, USA
- Institute for Antiviral Research, Utah State University, Logan, Utah, USA
| | - Rachel S. Furnell
- Department of Animal Dairy and Veterinary Sciences, Utah State University, Logan, Utah, USA
- Institute for Antiviral Research, Utah State University, Logan, Utah, USA
| | - Samantha R. Wasson
- Department of Animal Dairy and Veterinary Sciences, Utah State University, Logan, Utah, USA
- Institute for Antiviral Research, Utah State University, Logan, Utah, USA
| | - Justin S. Murray
- Department of Animal Dairy and Veterinary Sciences, Utah State University, Logan, Utah, USA
- Institute for Antiviral Research, Utah State University, Logan, Utah, USA
| | - Rakesh Kaundal
- Department of Plants, Soils, and Climate, Utah State University, Logan, Utah, USA
- Center for Integrated BioSystems, Utah State University, Logan, Utah, USA
| | - Aaron J. Thomas
- Department of Animal Dairy and Veterinary Sciences, Utah State University, Logan, Utah, USA
- Center for Integrated BioSystems, Utah State University, Logan, Utah, USA
| | - Brian B. Gowen
- Department of Animal Dairy and Veterinary Sciences, Utah State University, Logan, Utah, USA
- Institute for Antiviral Research, Utah State University, Logan, Utah, USA
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Li HL, Zhong LY, Kang YF, Yang YL, Shi L, Zhai AX, Wu C, Zeng MS, Zhu QY. Evaluation of serum Epstein-Barr virus envelope glycoproteins antibodies and their association with systemic autoimmune diseases. J Med Virol 2024; 96:e29595. [PMID: 38587217 DOI: 10.1002/jmv.29595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 03/20/2024] [Accepted: 03/28/2024] [Indexed: 04/09/2024]
Abstract
Systemic autoimmune diseases (SADs) are a growing spectrum of autoimmune disorders that commonly affect multiple organs. The role of Epstein-Barr virus (EBV) infection or reactivation as a trigger for the initiation and progression of SADs has been established, while the relationship between EBV envelope glycoproteins and SADs remains unclear. Here, we assessed the levels of IgG, IgA, and IgM against EBV glycoproteins (including gp350, gp42, gHgL, and gB) in serum samples obtained from patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), and found that RA and SLE patients exhibited a statistically significant increase in the levels of 8 and 11 glycoprotein antibodies, respectively, compared to healthy controls (p < 0.05). The LASSO model identified four factors as significant diagnostic markers for RA: gp350 IgG, gp350 IgA, gHgL IgM, and gp42 IgA; whereas for SLE it included gp350 IgG, gp350 IgA, gHgL IgA, and gp42 IgM. Combining these selected biomarkers yielded an area under the curve (AUC) of 0.749 for RA and 0.843 for SLE. We subsequently quantified the levels of autoantibodies associated with SADs in mouse sera following immunization with gp350. Remarkably, none of the tested autoantibody levels exhibited statistically significant alterations. Elevation of glycoprotein antibody concentration suggests that Epstein-Barr virus reactivation and replication occurred in SADs patients, potentially serving as a promising biomarker for diagnosing SADs. Moreover, the absence of cross-reactivity between gp350 antibodies and SADs-associated autoantigens indicates the safety profile of a vaccine based on gp350 antigen.
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Affiliation(s)
- Hui-Lan Li
- Department of Laboratory Medicine, The Eighth Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Lan-Yi Zhong
- State Key Laboratory of Oncology in South China, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Yin-Feng Kang
- State Key Laboratory of Oncology in South China, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Yan-Lan Yang
- Department of Laboratory Medicine, The Eighth Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Liang Shi
- Department of Laboratory Medicine, The Eighth Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Ai-Xia Zhai
- Department of Laboratory Medicine, The Eighth Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Chao Wu
- Department of Laboratory Medicine, The Eighth Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Mu-Sheng Zeng
- State Key Laboratory of Oncology in South China, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Qian-Ying Zhu
- Department of Laboratory Medicine, The Eighth Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
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Ao Y, Grover JR, Gifford L, Han Y, Zhong G, Katte R, Li W, Bhattacharjee R, Zhang B, Sauve S, Qin W, Ghimire D, Haque MA, Arthos J, Moradi M, Mothes W, Lemke EA, Kwong PD, Melikyan GB, Lu M. Bioorthogonal click labeling of an amber-free HIV-1 provirus for in-virus single molecule imaging. Cell Chem Biol 2024; 31:487-501.e7. [PMID: 38232732 PMCID: PMC10960674 DOI: 10.1016/j.chembiol.2023.12.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 10/13/2023] [Accepted: 12/21/2023] [Indexed: 01/19/2024]
Abstract
Structural dynamics of human immunodeficiency virus 1 (HIV-1) envelope (Env) glycoprotein mediate cell entry and facilitate immune evasion. Single-molecule FRET using peptides for Env labeling revealed structural dynamics of Env, but peptide use risks potential effects on structural integrity/dynamics. While incorporating noncanonical amino acids (ncAAs) into Env by amber stop-codon suppression, followed by click chemistry, offers a minimally invasive approach, this has proved to be technically challenging for HIV-1. Here, we develope an intact amber-free HIV-1 system that overcomes hurdles of preexisting viral amber codons. We achieved dual-ncAA incorporation into Env on amber-free virions, enabling single-molecule Förster resonance energy transfer (smFRET) studies of click-labeled Env that validated the previous peptide-based labeling approaches by confirming the intrinsic propensity of Env to dynamically sample multiple conformational states. Amber-free click-labeled Env also enabled real-time tracking of single virion internalization and trafficking in cells. Our system thus permits in-virus bioorthogonal labeling of proteins, compatible with studies of virus entry, trafficking, and egress from cells.
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Affiliation(s)
- Yuanyun Ao
- Department of Cellular and Molecular Biology, School of Medicine, University of Texas at Tyler Health Science Center, Tyler, TX 75708, USA
| | - Jonathan R Grover
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Levi Gifford
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Yang Han
- Department of Cellular and Molecular Biology, School of Medicine, University of Texas at Tyler Health Science Center, Tyler, TX 75708, USA
| | - Guohua Zhong
- Department of Cellular and Molecular Biology, School of Medicine, University of Texas at Tyler Health Science Center, Tyler, TX 75708, USA
| | - Revansiddha Katte
- Department of Cellular and Molecular Biology, School of Medicine, University of Texas at Tyler Health Science Center, Tyler, TX 75708, USA
| | - Wenwei Li
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Rajanya Bhattacharjee
- Biocentre, Departments of Biology and Chemistry, Johannes Gutenberg-University Mainz, Hanns-Dieter-Hüsch-Weg 17, 55128 Mainz, Germany; International PhD Program of the Institute of Molecular Biology, Hanns-Dieter-Hüsch-Weg 17, 55128 Mainz, Germany
| | - Baoshan Zhang
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Stephanie Sauve
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA
| | - Wenyi Qin
- Department of Cellular and Molecular Biology, School of Medicine, University of Texas at Tyler Health Science Center, Tyler, TX 75708, USA
| | - Dibya Ghimire
- Department of Cellular and Molecular Biology, School of Medicine, University of Texas at Tyler Health Science Center, Tyler, TX 75708, USA
| | - Md Anzarul Haque
- Department of Cellular and Molecular Biology, School of Medicine, University of Texas at Tyler Health Science Center, Tyler, TX 75708, USA
| | - James Arthos
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Mahmoud Moradi
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA
| | - Walther Mothes
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Edward A Lemke
- Biocentre, Departments of Biology and Chemistry, Johannes Gutenberg-University Mainz, Hanns-Dieter-Hüsch-Weg 17, 55128 Mainz, Germany; Institute of Molecular Biology, Ackermannweg 4, 55128 Mainz, Germany
| | - Peter D Kwong
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Gregory B Melikyan
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Maolin Lu
- Department of Cellular and Molecular Biology, School of Medicine, University of Texas at Tyler Health Science Center, Tyler, TX 75708, USA.
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4
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Wang Q, Zhang S, Nguyen HT, Sodroski J. Inhibition of human immunodeficiency virus (HIV-1) infectivity by expression of poorly or broadly neutralizing antibodies against Env in virus-producing cells. J Virol 2024; 98:e0159423. [PMID: 38289101 PMCID: PMC10878270 DOI: 10.1128/jvi.01594-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 12/19/2023] [Indexed: 02/21/2024] Open
Abstract
The human immunodeficiency virus (HIV-1) envelope (Env) glycoprotein precursor (gp160) trimerizes, is modified by high-mannose glycans in the endoplasmic reticulum, and is transported via Golgi and non-Golgi secretory pathways to the infected cell surface. In the Golgi, gp160 is partially modified by complex carbohydrates and proteolytically cleaved to produce the mature functional Env trimer, which is preferentially incorporated into virions. Broadly neutralizing antibodies (bNAbs) generally recognize the cleaved Env trimer, whereas poorly neutralizing antibodies (pNAbs) bind the conformationally flexible gp160. We found that expression of bNAbs, pNAbs, or soluble/membrane forms of the receptor, CD4, in cells producing HIV-1 all decreased viral infectivity. Four patterns of co-expressed ligand:Env were observed: (i) ligands (CD4, soluble CD4-Ig, and some pNAbs) that specifically recognize the CD4-bound Env conformation resulted in uncleaved Envs lacking complex glycans that were not incorporated into virions; (ii) other pNAbs produced Envs with some complex carbohydrates and severe defects in cleavage, which were relieved by brefeldin A treatment; (iii) bNAbs that recognize gp160 as well as mature Envs resulted in Envs with some complex carbohydrates and moderate decreases in virion Env cleavage; and (iv) bNAbs that preferentially recognize mature Envs produced cleaved Envs with complex glycans in cells and on virions. The low infectivity observed upon co-expression of pNAbs or CD4 could be explained by disruption of Env trafficking, reducing the level of Env and/or increasing the fraction of uncleaved Env on virions. In addition to bNAb effects on virion Env cleavage, the secreted bNAbs neutralized the co-expressed viruses.IMPORTANCEThe Env trimers on the HIV-1 mediate virus entry into host cells. Env is synthesized in infected cells, modified by complex sugars, and cleaved to form a mature, functional Env, which is incorporated into virus particles. Env elicits antibodies in infected individuals, some of which can neutralize the virus. We found that antibodies co-expressed in the virus-producing cell can disrupt Env transit to the proper compartment for cleavage and sugar modification and, in some cases, block incorporation into viruses. These studies provide insights into the processes by which Env becomes functional in the virus-producing cell and may assist attempts to interfere with these events to inhibit HIV-1 infection.
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Affiliation(s)
- Qian Wang
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Shijian Zhang
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Hanh T. Nguyen
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Joseph Sodroski
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
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5
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Yu C, Bai Y, Tan W, Bai Y, Li X, Zhou Y, Zhai J, Xue M, Tang YD, Zheng C, Liu Q. Human MARCH1, 2, and 8 block Ebola virus envelope glycoprotein cleavage via targeting furin P domain. J Med Virol 2024; 96:e29445. [PMID: 38299743 DOI: 10.1002/jmv.29445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 01/19/2024] [Accepted: 01/21/2024] [Indexed: 02/02/2024]
Abstract
Membrane-associated RING-CH (MARCH) family proteins were recently reported to inhibit viral replication through multiple modes. Previous work showed that human MARCH8 blocked Ebola virus (EBOV) glycoprotein (GP) maturation. Our study here demonstrates that human MARCH1 and MARCH2 share a similar pattern to MARCH8 in restricting EBOV GP-pseudotyped viral infection. Human MARCH1 and MARCH2 retain EBOV GP at the trans-Golgi network, reduce its cell surface display, and impair EBOV GP-pseudotyped virions infectivity. Furthermore, we uncover that the host proprotein convertase furin could interact with human MARCH1/2 and EBOV GP intracellularly. Importantly, the furin P domain is verified to be recognized by MARCH1/2/8, which is critical for their blocking activities. Besides, bovine MARCH2 and murine MARCH1 also impair EBOV GP proteolytic processing. Altogether, our findings confirm that MARCH1/2 proteins of different mammalian origins showed a relatively conserved feature in blocking EBOV GP cleavage, which could provide clues for subsequent MARCHs antiviral studies and may facilitate the development of novel strategies to antagonize enveloped virus infection.
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Affiliation(s)
- Changqing Yu
- Engineering Center of Agricultural Biosafety Assessment and Biotechnology, School of Advanced Agricultural Sciences, Yibin Vocational and Technical College, Yibin, People's Republic of China
| | - Yuanzhe Bai
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Wenbo Tan
- College of Advanced Agriculture and Ecological Environment, Heilongjiang University, Harbin, People's Republic of China
| | - Yu Bai
- College of Animal Science, Wenzhou Vocational College of Science and Technology, Wenzhou, People's Republic of China
| | - Xuemei Li
- Engineering Center of Agricultural Biosafety Assessment and Biotechnology, School of Advanced Agricultural Sciences, Yibin Vocational and Technical College, Yibin, People's Republic of China
| | - Yulong Zhou
- College of Animal Science and Technology, Heilongjiang Bayi Agricultural University, Daqing, People's Republic of China
| | - Jingbo Zhai
- Key Laboratory of Zoonose Prevention and Control at Universities of Inner Mongolia Autonomous Region, Medical College, Inner Mongolia Minzu University, Tongliao, People's Republic of China
| | - Mengzhou Xue
- Department of Cerebrovascular Diseases, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China
| | - Yan-Dong Tang
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Chunfu Zheng
- Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Key Laboratory of Livestock Disease Prevention of Guangdong Province, Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Ministry of Agriculture and Rural Affairs, Guangzhou, People's Republic of China
- Department of Microbiology, Immunology & Infection Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Qiang Liu
- Nanchong Key Laboratory of Disease Prevention, Control and Detection in Livestock and Poultry, Nanchong Vocational and Technical College, Nanchong, People's Republic of China
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da Rocha JM, Campos DMDO, Esmaile SC, Menezes GDL, Bezerra KS, da Silva RA, Junior EDDS, Tayyeb JZ, Akash S, Fulco UL, Alqahtani T, Oliveira JIN. Quantum biochemical analysis of the binding interactions between a potential inhibitory drug and the Ebola viral glycoprotein. J Biomol Struct Dyn 2024:1-17. [PMID: 38258414 DOI: 10.1080/07391102.2024.2305314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 01/08/2024] [Indexed: 01/24/2024]
Abstract
Ebola virus disease (EVD) causes outbreaks and epidemics in West Africa that persist until today. The envelope glycoprotein of Ebola virus (GP) consists of two subunits, GP1 and GP2, and plays a key role in anchoring or fusing the virus to the host cell in its active form on the virion surface. Toremifene (TOR) is a ligand that mainly acts as an estrogen receptor antagonist; however, a recent study showed a strong and efficient interaction with GP. In this context, we aimed to evaluate the energetic affinity features involved in the interaction between GP and toremifene by computer simulation techniques using the Molecular Fractionation Method with Conjugate Caps (MFCC) scheme and quantum-mechanical (QM) calculations, as well as missense mutations to assess protein stability. We identified ASP522, GLU100, TYR517, THR519, LEU186, LEU515 as the most attractive residues in the EBOV glycoprotein structure that form the binding pocket. We divided toremifene into three regions and evaluated that region i was more important than region iii and region ii for the formation of the TOR-GP1/GP2 complex, which might control the molecular remodeling process of TOR. The mutations that caused more destabilization were ARG134, LEU515, TYR517 and ARG559, while those that caused stabilization were GLU523 and ASP522. TYR517 is a critical residue for the binding of TOR, and is highly conserved among EBOV species. Our results may help to elucidate the mechanism of drug action on the GP protein of the Ebola virus and subsequently develop new pharmacological approaches against EVD.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Jaerdyson M da Rocha
- Department of Biophysics and Pharmacology, Bioscience Center, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - Daniel M de O Campos
- Department of Biophysics and Pharmacology, Bioscience Center, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - Stephany C Esmaile
- Department of Biophysics and Pharmacology, Bioscience Center, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - Gabriela de L Menezes
- Department of Biophysics and Pharmacology, Bioscience Center, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - Katyanna S Bezerra
- Department of Biophysics and Pharmacology, Bioscience Center, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - Roosevelt A da Silva
- Core Collaboratives of BioSistemas, Special Unit of Exact Sciences, Federal University of Jataí, Jataí, GO, Brazil
| | - Edilson D da S Junior
- Department of Biophysics and Pharmacology, Bioscience Center, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - Jehad Zuhair Tayyeb
- Department of Clinical Biochemistry, College of Medicine, University of Jeddah, Jeddah, Saudi Arabia
| | - Shopnil Akash
- Department of Pharmacy, Faculty of Allied Health Sciences, Daffodil International University, Birulia, Ashulia, Dhaka, Bangladesh
| | - Umberto L Fulco
- Department of Biophysics and Pharmacology, Bioscience Center, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - Taha Alqahtani
- Department of Pharmacology, College of Pharmacy, King Khalid University, Abha, Saudi Arabia
| | - Jonas I N Oliveira
- Department of Biophysics and Pharmacology, Bioscience Center, Federal University of Rio Grande do Norte, Natal, RN, Brazil
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Wang S, Chan KW, Wei D, Ma X, Liu S, Hu G, Park S, Pan R, Gu Y, Nazzari AF, Olia AS, Xu K, Lin BC, Louder MK, Doria-Rose NA, Montefiori D, Seaman MS, Zhou T, Kwong PD, Arthos J, Kong XP, Lu S. Human CD4-Binding Site Antibody Elicited by Polyvalent DNA Prime-Protein Boost Vaccine Neutralizes Cross-Clade Tier-2-HIV Strains. Res Sq 2023:rs.3.rs-3360161. [PMID: 37886518 PMCID: PMC10602183 DOI: 10.21203/rs.3.rs-3360161/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2023]
Abstract
The vaccine elicitation of HIV-neutralizing antibodies with tier-2-neutralization breadth has been a challenge. Here, we report the isolation and characteristics of a CD4-binding site specific monoclonal antibody, HmAb64, from a human volunteer immunized with a polyvalent gp120 DNA prime-protein boost vaccine. HmAb64 derived from heavy chain variable germline gene IGHV1-18, light chain germline gene IGKV1-39, and had a 3rd heavy chain complementarity determining region (CDR H3) of 15 amino acids. On a cross-clade panel of 208 HIV-1 pseudo-virus strains, HmAb64 neutralized 21 (10%), including tier-2 neutralization resistant strains from clades B, BC, C, and G. The cryo-EM structure of the antigen-binding fragment of HmAb64 bound to a conformation between prefusion closed and occluded open forms of envelope trimer, using both heavy and light CDR3s to recognize the CD4-binding loop, a critical component of the CD4-binding site. A gp120 subunit-based vaccine can thus elicit an antibody capable of tier 2-HIV neutralization.
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Affiliation(s)
- Shixia Wang
- Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA
| | - Kun-Wei Chan
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Danlan Wei
- Laboratory of Immune Regulation, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Xiuwen Ma
- Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA
| | | | - Guangnan Hu
- Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA
| | - Saeyoung Park
- Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA
| | - Ruimin Pan
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Ying Gu
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Alexandra F Nazzari
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Adam S Olia
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Kai Xu
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Bob C Lin
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Mark K Louder
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Nicole A Doria-Rose
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | | | - Michael S Seaman
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Tongqing Zhou
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Peter D Kwong
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - James Arthos
- Laboratory of Immune Regulation, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Xiang-Peng Kong
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Shan Lu
- Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA
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8
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Tury S, Chauveau L, Lecante A, Courgnaud V, Battini JL. A co-opted endogenous retroviral envelope promotes cell survival by controlling CTR1-mediated copper transport and homeostasis. Cell Rep 2023; 42:113065. [PMID: 37682705 DOI: 10.1016/j.celrep.2023.113065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 06/14/2023] [Accepted: 08/21/2023] [Indexed: 09/10/2023] Open
Abstract
Copper is a critical element for eukaryotic life involved in numerous cellular functions, including redox balance, but is toxic in excess. Therefore, tight regulation of copper acquisition and homeostasis is essential for cell physiology and survival. Here, we identify a different regulatory mechanism for cellular copper homeostasis that requires the presence of an endogenous retroviral envelope glycoprotein called Refrex1. We show that cells respond to elevated extracellular copper by increasing the expression of Refrex1, which regulates copper acquisition through interaction with the main copper transporter CTR1. Downmodulation of Refrex1 results in intracellular copper accumulation leading to reactive oxygen species (ROS) production and subsequent apoptosis, which is prevented by copper chelator treatment. Our results show that Refrex1 has been co-opted for its ability to regulate copper entry through CTR1 in order to limit copper excess, redox imbalance, and ensuing cell death, strongly suggesting that other endogenous retroviruses may have similar metabolic functions among vertebrates.
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Affiliation(s)
- Sandrine Tury
- Institut de Recherche en Infectiologie de Montpellier IRIM - CNRS UMR 9004, Université Montpellier, 34293 Montpellier Cedex 5, France
| | - Lise Chauveau
- Institut de Recherche en Infectiologie de Montpellier IRIM - CNRS UMR 9004, Université Montpellier, 34293 Montpellier Cedex 5, France
| | - Arnaud Lecante
- Institut de Recherche en Infectiologie de Montpellier IRIM - CNRS UMR 9004, Université Montpellier, 34293 Montpellier Cedex 5, France
| | - Valérie Courgnaud
- Institut de Génétique Moléculaire de Montpellier IGMM - CNRS UMR 5535, Université Montpellier, 34293 Montpellier Cedex 5, France.
| | - Jean-Luc Battini
- Institut de Recherche en Infectiologie de Montpellier IRIM - CNRS UMR 9004, Université Montpellier, 34293 Montpellier Cedex 5, France.
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9
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Weaver N, Hammonds J, Ding L, Lerner G, Dienger-Stambaugh K, Spearman P. KIF16B Mediates Anterograde Transport and Modulates Lysosomal Degradation of the HIV-1 Envelope Glycoprotein. J Virol 2023; 97:e0025523. [PMID: 37358446 PMCID: PMC10373548 DOI: 10.1128/jvi.00255-23] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 06/08/2023] [Indexed: 06/27/2023] Open
Abstract
The human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) is incorporated into virions at the site of particle assembly on the plasma membrane (PM). The route taken by Env to reach the site of assembly and particle incorporation remains incompletely understood. Following initial delivery to the PM through the secretory pathway, Env is rapidly endocytosed, suggesting that recycling is required for particle incorporation. Endosomes marked by the small GTPase Rab14 have been previously shown to play a role in Env trafficking. Here, we examined the role of KIF16B, the molecular motor protein that directs outward movement of Rab14-dependent cargo, in Env trafficking. Env colocalized extensively with KIF16B+ endosomes at the cellular periphery, while expression of a motor-deficient mutant of KIF16B redistributed Env to a perinuclear location. The half-life of Env labeled at the cell surface was markedly reduced in the absence of KIF16B, while a normal half-life was restored through inhibition of lysosomal degradation. In the absence of KIF16B, Env expression on the surface of cells was reduced, leading to a reduction in Env incorporation into particles and a corresponding reduction in particle infectivity. HIV-1 replication in KIF16B knockout cells was substantially reduced compared to that in wild-type cells. These results indicated that KIF16B regulates an outward sorting step involved in Env trafficking, thereby limiting lysosomal degradation and enhancing particle incorporation. IMPORTANCE The HIV-1 envelope glycoprotein is an essential component of HIV-1 particles. The cellular pathways that contribute to incorporation of envelope into particles are not fully understood. Here, we have identified KIF16B, a motor protein that directs movement from internal compartments toward the plasma membrane, as a host factor that prevents envelope degradation and enhances particle incorporation. This is the first host motor protein identified that contributes to HIV-1 envelope incorporation and replication.
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Affiliation(s)
- Nicholas Weaver
- Immunobiology Division, Cincinnati Children’s Hospital Medical Center and University of Cincinnati, Cincinnati, Ohio, USA
- Infectious Diseases, Cincinnati Children’s Hospital Medical Center and University of Cincinnati, Cincinnati, Ohio, USA
| | - Jason Hammonds
- Infectious Diseases, Cincinnati Children’s Hospital Medical Center and University of Cincinnati, Cincinnati, Ohio, USA
| | - Lingmei Ding
- Infectious Diseases, Cincinnati Children’s Hospital Medical Center and University of Cincinnati, Cincinnati, Ohio, USA
| | - Grigoriy Lerner
- Immunobiology Division, Cincinnati Children’s Hospital Medical Center and University of Cincinnati, Cincinnati, Ohio, USA
- Infectious Diseases, Cincinnati Children’s Hospital Medical Center and University of Cincinnati, Cincinnati, Ohio, USA
| | - Krista Dienger-Stambaugh
- Infectious Diseases, Cincinnati Children’s Hospital Medical Center and University of Cincinnati, Cincinnati, Ohio, USA
| | - Paul Spearman
- Infectious Diseases, Cincinnati Children’s Hospital Medical Center and University of Cincinnati, Cincinnati, Ohio, USA
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10
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Xin X, Liu Y, Guo L, Wang H, Lu D, Chang Y, Wan M, Zhang Y, Shan Y, Zhang Q, Liu X, Gao F. Improvement of B Cell Responses by an HIV-1 Amphiphilic Polymer Nanovaccine. Nano Lett 2023; 23:4090-4094. [PMID: 37120753 DOI: 10.1021/acs.nanolett.3c01241] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The human immunodeficiency virus (HIV) has infected over 84 million people since its discovery and is a huge threat to human health. While an HIV vaccine is urgently needed to curb this devastating pandemic, it has been notoriously difficult to develop, partly due to the extraordinary high level of genetic variation of HIV. We designed a new HIV-1 envelope glycoprotein nanoparticle (Env/NP) vaccine using amphiphilic polymers. The Env/NP vaccine induced more potent and broader neutralizing activities against multiple HIV-1 subtypes. Moreover, it elicits similar neutralizing antibody responses after the storage at -80 °C, 4 °C or room temperature post lyophilization. These results demonstrate that the new Env/NP vaccine not only improves the HIV vaccine immune responses but also is stable under different storage conditions. This new nanovaccine approach can readily apply to other protein-based vaccines.
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Affiliation(s)
- Xiaoqian Xin
- Institute of Molecular and Medical Virology, Key Laboratory of Ministry of Education for Viral Pathogenesis & Infection Prevention and Control, School of Medicine, Jinan University, Guangzhou, Guangdong Province 510632, China
| | - Yifeng Liu
- Institute of Molecular and Medical Virology, Key Laboratory of Ministry of Education for Viral Pathogenesis & Infection Prevention and Control, School of Medicine, Jinan University, Guangzhou, Guangdong Province 510632, China
| | - Lei Guo
- Institute of Molecular and Medical Virology, Key Laboratory of Ministry of Education for Viral Pathogenesis & Infection Prevention and Control, School of Medicine, Jinan University, Guangzhou, Guangdong Province 510632, China
| | - Hui Wang
- Institute of Molecular and Medical Virology, Key Laboratory of Ministry of Education for Viral Pathogenesis & Infection Prevention and Control, School of Medicine, Jinan University, Guangzhou, Guangdong Province 510632, China
| | - Daiqiang Lu
- Institute of Molecular and Medical Virology, Key Laboratory of Ministry of Education for Viral Pathogenesis & Infection Prevention and Control, School of Medicine, Jinan University, Guangzhou, Guangdong Province 510632, China
| | - Yaotian Chang
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, Jilin Province 130012, China
| | - Mingming Wan
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, Jilin Province 130012, China
| | - Yong Zhang
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, Jilin Province 130012, China
| | - Yaming Shan
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, Jilin Province 130012, China
| | - Qiao Zhang
- Institute of Molecular and Medical Virology, Key Laboratory of Ministry of Education for Viral Pathogenesis & Infection Prevention and Control, School of Medicine, Jinan University, Guangzhou, Guangdong Province 510632, China
| | - Xiaowen Liu
- Engineering Center of Catalysis and Synthesis for Chiral Molecules, Department of Chemistry, Fudan University, 220 Handan Road, Shanghai 200433, China
- Shanghai Engineering Research Center of Industrial Asymmetric Catalysis of Chiral Drugs, 220 Handan Road, Shanghai 200433, China
| | - Feng Gao
- Institute of Molecular and Medical Virology, Key Laboratory of Ministry of Education for Viral Pathogenesis & Infection Prevention and Control, School of Medicine, Jinan University, Guangzhou, Guangdong Province 510632, China
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11
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Cassari L, Pavan A, Zoia G, Chinellato M, Zeni E, Grinzato A, Rothenberger S, Cendron L, Dettin M, Pasquato A. SARS-CoV-2 S Mutations: A Lesson from the Viral World to Understand How Human Furin Works. Int J Mol Sci 2023; 24:4791. [PMID: 36902222 PMCID: PMC10003014 DOI: 10.3390/ijms24054791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 02/17/2023] [Accepted: 02/20/2023] [Indexed: 03/06/2023] Open
Abstract
Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the etiological agent responsible for the worldwide pandemic and has now claimed millions of lives. The virus combines several unusual characteristics and an extraordinary ability to spread among humans. In particular, the dependence of the maturation of the envelope glycoprotein S from Furin enables the invasion and replication of the virus virtually within the entire body, since this cellular protease is ubiquitously expressed. Here, we analyzed the naturally occurring variation of the amino acids sequence around the cleavage site of S. We found that the virus grossly mutates preferentially at P positions, resulting in single residue replacements that associate with gain-of-function phenotypes in specific conditions. Interestingly, some combinations of amino acids are absent, despite the evidence supporting some cleavability of the respective synthetic surrogates. In any case, the polybasic signature is maintained and, as a consequence, Furin dependence is preserved. Thus, no escape variants to Furin are observed in the population. Overall, the SARS-CoV-2 system per se represents an outstanding example of the evolution of substrate-enzyme interaction, demonstrating a fast-tracked optimization of a protein stretch towards the Furin catalytic pocket. Ultimately, these data disclose important information for the development of drugs targeting Furin and Furin-dependent pathogens.
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Affiliation(s)
- Leonardo Cassari
- Department of Industrial Engineering, University of Padova, Via Marzolo 9, 35131 Padova, Italy
| | - Angela Pavan
- Department of Biology, University of Padua, Viale G. Colombo 3, 35131 Padova, Italy
| | - Giulia Zoia
- Department of Biology, University of Padua, Viale G. Colombo 3, 35131 Padova, Italy
| | - Monica Chinellato
- Department of Biology, University of Padua, Viale G. Colombo 3, 35131 Padova, Italy
| | - Elena Zeni
- Department of Industrial Engineering, University of Padova, Via Marzolo 9, 35131 Padova, Italy
| | - Alessandro Grinzato
- European Synchrotron Radiation Facility, 71, Avenue des Martyrs, 38000 Grenoble, France
| | - Sylvia Rothenberger
- Institute of Microbiology, University Hospital Center and University of Lausanne, Rue du Bugnon 48, 1011 Lausanne, Switzerland
- Spiez Laboratory, Federal Office for Civil Protection, Austrasse, 3700 Spiez, Switzerland
| | - Laura Cendron
- Department of Biology, University of Padua, Viale G. Colombo 3, 35131 Padova, Italy
| | - Monica Dettin
- Department of Industrial Engineering, University of Padova, Via Marzolo 9, 35131 Padova, Italy
| | - Antonella Pasquato
- Department of Industrial Engineering, University of Padova, Via Marzolo 9, 35131 Padova, Italy
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12
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Liu J, Mao Y, Li Q, Qiu Z, Li J, Li X, Liang W, Xu M, Li A, Cai X, Wu W, Chen H, Yan R, Li J, Gu W, Li H. Efficient Gene Transfer to Kidney Using a Lentiviral Vector Pseudotyped with Zika Virus Envelope Glycoprotein. Hum Gene Ther 2022; 33:1269-1278. [PMID: 35904396 DOI: 10.1089/hum.2022.053] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Gene therapy's entrance into clinical settings has made it an ever more attractive field of study for various diseases. However, relatively little progress has been made in targeting kidney diseases due to poor gene delivery efficiency in renal cells. The development of novel gene therapy vectors for medical intervention to treat kidney diseases is needed. In this study, we designed and produced a pseudotyped lentiviral vector with envelope glycoproteins of Zika virus (ZIKV), and evaluated its potential use in viral vector entry, neutralization assay, and gene delivery especially in the renal context. The lentiviral vector, simplified as ZIKV-E, is pseudotyped with Env/G-TC representing the transmembrane (TM) and cytoplasmic (CY) domains of Env replaced with the TM and CY domains of the glycoprotein (G) of the vesicular stomatitis virus. In vivo results show that ZIKV-E induced efficient transduction in tubular epithelial cells in mouse kidneys, demonstrating >100-fold higher expression of exogenous green fluorescent protein gene compared with that achieved by vesicular stomatitis virus G (VSV-G) protein pseudotyped lentiviral vector. The results also showed that the vector ZIKV-E transduced cells in a pH-independent manner and the transduction was inhibited by anti-ZIKV Env domain III antibodies. Results also show that ZIKV-E can be used as a surrogate for studies of ZIKV entry mechanisms and neutralization antibody assay. In all, this study successfully demonstrated a novel pseudotyped lentiviral vector ZIKV-E for inducing high transduction efficiency in renal tubular epithelial cells that could serve as a foundation for gene therapy for the treatment of inherited renal diseases in humans.
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Affiliation(s)
- Jun Liu
- School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China.,Institute of Dermatology and Venereology, Dermatology Hospital, Southern Medical University, Guangzhou, China
| | - Yingying Mao
- School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Qingqing Li
- School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China.,Clinical Laboratory, Foshan Women and Children Hospital, Foshan, China
| | - Zhenzhen Qiu
- Guangzhou Bioneeds Biotechnology Co., Ltd, Guangzhou, China
| | - Jingjing Li
- School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Xiaoxin Li
- School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Wenhan Liang
- School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Mingyu Xu
- School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Andrew Li
- Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Xiangsheng Cai
- Center for Medical Experiments, University of Chinese Academy of Science-Shenzhen Hospital, Shenzhen, China; and
| | - Wangsheng Wu
- School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Huangyao Chen
- School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Renhe Yan
- Guangzhou Bioneeds Biotechnology Co., Ltd, Guangzhou, China
| | - Jinlong Li
- School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Weiwang Gu
- School of Biotechnology and Health Sciences, Wuyi University, Jiangmen, China
| | - Hongwei Li
- School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
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13
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Anokhin B, Spearman P. Viral and Host Factors Regulating HIV-1 Envelope Protein Trafficking and Particle Incorporation. Viruses 2022; 14:1729. [PMID: 36016351 DOI: 10.3390/v14081729] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 07/25/2022] [Accepted: 08/02/2022] [Indexed: 11/17/2022] Open
Abstract
The HIV-1 envelope glycoprotein (Env) is an essential structural component of the virus, serving as the receptor-binding protein and principal neutralizing determinant. Env trimers are incorporated into developing particles at the plasma membrane of infected cells. Incorporation of HIV-1 Env into particles in T cells and macrophages is regulated by the long Env cytoplasmic tail (CT) and the matrix region of Gag. The CT incorporates motifs that interact with cellular factors involved in endosomal trafficking. Env follows an unusual pathway to arrive at the site of particle assembly, first traversing the secretory pathway to the plasma membrane (PM), then undergoing endocytosis, followed by directed sorting to the site of particle assembly on the PM. Many aspects of Env trafficking remain to be defined, including the sequential events that occur following endocytosis, leading to productive recycling and particle incorporation. This review focuses on the host factors and pathways involved in Env trafficking, and discusses leading models of Env incorporation into particles.
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14
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Hoffman HK, Aguilar RS, Clark AR, Groves NS, Pezeshkian N, Bruns MM, van Engelenburg SB. Endocytosed HIV-1 Envelope Glycoprotein Traffics to Rab14 + Late Endosomes and Lysosomes to Regulate Surface Levels in T-Cell Lines. J Virol 2022; 96:e0076722. [PMID: 35770989 PMCID: PMC9327703 DOI: 10.1128/jvi.00767-22] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Accepted: 06/06/2022] [Indexed: 11/20/2022] Open
Abstract
Production of infectious HIV-1 particles requires incorporation of the viral envelope glycoprotein (Env) at the plasma membrane (PM) of infected CD4+ T cells. Env trafficking to the PM exposes viral epitopes that can be exploited by the host immune system; however, HIV-1 can evade this response by endocytosis of excess Env from the PM. The fate of Env after internalization remains unclear, with evidence suggesting several different vesicular trafficking steps may be involved, including recycling pathways. To date, there have been very few studies documenting the trafficking pathways of native Env in infected T cells. Furthermore, it remains unclear whether there are T-cell-specific endosomal pathways regulating the fate of endocytic Env. Here, we use a pulse-labeling approach with a monovalent anti-Env Fab probe to characterize the trafficking of internalized Env within infected CD4+ T-cell lines, together with CRISPR/Cas9-mediated endogenous protein tagging, to assess the role of host cell Rab GTPases in Env trafficking. We show that endocytosed Env traffics to Rab14+ compartments that possess hallmarks of late endosomes and lysosomes. We also demonstrate that Env can recycle back to the PM, although we find that recycling does not occur at high rates when compared to the model recycling protein transferrin. These results help to resolve open questions about the fate and relevance of endocytosed Env in HIV-infected cells and suggest a novel role for Rab14 in a cell-type-specific late-endosomal/lysosomal trafficking pathway in T cells. IMPORTANCE HIV-1 envelope glycoprotein (Env) evades immune neutralization through many mechanisms. One immune evasion strategy may result from the internalization of excess surface-exposed Env to prevent antibody-dependent cellular cytotoxicity or neutralization. Characterization of the fate of endocytosed Env is critical to understand which vesicular pathways could be targeted to promote display of Env epitopes to the immune system. In this study, we characterize the endocytic fate of native Env, expressed from infected human T-cell lines. We demonstrate that Env is rapidly trafficked to a late-endosome/lysosome-like compartment and can be recycled to the cell surface for incorporation into virus assembly sites. This study implicates a novel intracellular compartment, marked by host-cell Rab14 GTPases, for the sequestration of Env. Therapeutic approaches aimed at mobilizing this intracellular pool of Env could lead to stronger immune control of HIV-1 infection via antibody-dependent cell-mediated cytotoxicity.
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Affiliation(s)
- Huxley K. Hoffman
- Molecular and Cellular Biophysics Program, Department of Biological Sciences, University of Denver, Denver, Colorado, USA
| | - Rebekah S. Aguilar
- Molecular and Cellular Biophysics Program, Department of Biological Sciences, University of Denver, Denver, Colorado, USA
| | - Austin R. Clark
- Molecular and Cellular Biophysics Program, Department of Biological Sciences, University of Denver, Denver, Colorado, USA
| | - Nicholas S. Groves
- Molecular and Cellular Biophysics Program, Department of Biological Sciences, University of Denver, Denver, Colorado, USA
| | - Nairi Pezeshkian
- Molecular and Cellular Biophysics Program, Department of Biological Sciences, University of Denver, Denver, Colorado, USA
| | - Merissa M. Bruns
- Molecular and Cellular Biophysics Program, Department of Biological Sciences, University of Denver, Denver, Colorado, USA
| | - Schuyler B. van Engelenburg
- Molecular and Cellular Biophysics Program, Department of Biological Sciences, University of Denver, Denver, Colorado, USA
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15
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Heydarchi B, Fong DS, Gao H, Salazar-Quiroz NA, Edwards JM, Gonelli CA, Grimley S, Aktepe TE, Mackenzie C, Wales WJ, van Gils MJ, Cupo A, Rouiller I, Gooley PR, Moore JP, Sanders RW, Montefiori D, Sethi A, Purcell DFJ. Broad and ultra-potent cross-clade neutralization of HIV-1 by a vaccine-induced CD4 binding site bovine antibody. Cell Rep Med 2022; 3:100635. [PMID: 35584627 PMCID: PMC9133467 DOI: 10.1016/j.xcrm.2022.100635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 01/27/2022] [Accepted: 04/22/2022] [Indexed: 11/30/2022]
Abstract
Human immunodeficiency virus type 1 (HIV-1) vaccination of cows has elicited broadly neutralizing antibodies (bNAbs). In this study, monoclonal antibodies (mAbs) are isolated from a clade A (KNH1144 and BG505) vaccinated cow using a heterologous clade B antigen (AD8). CD4 binding site (CD4bs) bNAb (MEL-1872) is more potent than a majority of CD4bs bNAbs isolated so far. MEL-1872 mAb with CDRH3 of 57 amino acids shows more potency (geometric mean half-maximal inhibitory concentration [IC50]: 0.009 μg/mL; breadth: 66%) than VRC01 against clade B viruses (29-fold) and than CHO1-31 against tested clade A viruses (21-fold). It also shows more breadth and potency than NC-Cow1, the only other reported anti-HIV-1 bovine bNAb, which has 60% breadth with geometric mean IC50 of 0.090 μg/mL in this study. Using successive different stable-structured SOSIP trimers in bovines can elicit bNAbs focusing on epitopes ubiquitous across subtypes. Furthermore, the cross-clade selection strategy also results in ultra-potent bNAbs. Sequential vaccine with different SOSIP trimers could elicit bNAbs Cross-clade B-cell-sorting probe could select ultra-potent bNAbs Bovine CD4bs monoclonal antibody neutralizes HIV-1 isolates potently
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Affiliation(s)
- Behnaz Heydarchi
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection Immunity, University of Melbourne, Melbourne, VIC 3000, Australia
| | - Danielle S Fong
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection Immunity, University of Melbourne, Melbourne, VIC 3000, Australia
| | - Hongmei Gao
- Department of Surgery, Duke University Medical Center, Durham, NC, USA
| | - Natalia A Salazar-Quiroz
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection Immunity, University of Melbourne, Melbourne, VIC 3000, Australia
| | - Jack M Edwards
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection Immunity, University of Melbourne, Melbourne, VIC 3000, Australia
| | - Christopher A Gonelli
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection Immunity, University of Melbourne, Melbourne, VIC 3000, Australia
| | - Samantha Grimley
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection Immunity, University of Melbourne, Melbourne, VIC 3000, Australia
| | - Turgut E Aktepe
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection Immunity, University of Melbourne, Melbourne, VIC 3000, Australia
| | - Charlene Mackenzie
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection Immunity, University of Melbourne, Melbourne, VIC 3000, Australia
| | - William J Wales
- Dairy Production Sciences, Victorian Department of Jobs, Precincts and Resources, Ellinbank, VIC, Australia; Centre for Agricultural Innovation, School of Agriculture and Food, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Melbourne, VIC 3010, Australia
| | - Marit J van Gils
- Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam Institute for Infection and Immunity, 1105AZ Amsterdam, the Netherlands
| | - Albert Cupo
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, NY 10021, USA
| | - Isabelle Rouiller
- Department of Biochemistry & Pharmacology, The University of Melbourne, Melbourne, VIC 3010, Australia; Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, VIC 3010, Australia; Australian Research Council Centre for Cryo-Electron Microscopy of Membrane Proteins, Parkville, VIC, Australia
| | - Paul R Gooley
- Department of Biochemistry & Pharmacology, The University of Melbourne, Melbourne, VIC 3010, Australia; Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, VIC 3010, Australia
| | - John P Moore
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, NY 10021, USA
| | - Rogier W Sanders
- Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam Institute for Infection and Immunity, 1105AZ Amsterdam, the Netherlands; Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, NY 10021, USA
| | - David Montefiori
- Department of Surgery, Duke University Medical Center, Durham, NC, USA
| | - Ashish Sethi
- Department of Biochemistry & Pharmacology, The University of Melbourne, Melbourne, VIC 3010, Australia; Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, VIC 3010, Australia
| | - Damian F J Purcell
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection Immunity, University of Melbourne, Melbourne, VIC 3000, Australia.
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16
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Pihl AF, Feng S, Offersgaard A, Alzua GP, Augestad EH, Mathiesen CK, Jensen TB, Krarup H, Law M, Prentoe J, Christensen JP, Bukh J, Gottwein JM. Inactivated whole hepatitis C virus vaccine employing a licensed adjuvant elicits cross-genotype neutralizing antibodies in mice. J Hepatol 2022; 76:1051-1061. [PMID: 34990750 DOI: 10.1016/j.jhep.2021.12.026] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Revised: 11/26/2021] [Accepted: 12/22/2021] [Indexed: 01/08/2023]
Abstract
BACKGROUND & AIMS A prophylactic vaccine is required to eliminate HCV as a global public health threat. We developed whole virus inactivated HCV vaccine candidates employing a licensed adjuvant. Further, we investigated the effects of HCV envelope protein modifications (to increase neutralization epitope exposure) on immunogenicity. METHODS Whole virus vaccine antigen was produced in Huh7.5 hepatoma cells, processed using a multistep protocol and formulated with adjuvant (MF-59 analogue AddaVax or aluminium hydroxide). We investigated the capacity of IgG purified from the serum of immunized BALB/c mice to neutralize genotype 1-6 HCV (by virus neutralization assays) and to bind homologous envelope proteins (by ELISA). Viruses used for immunizations were (i) HCV5aHi with strain SA13 envelope proteins and modification of an O-linked glycosylation site in E2 (T385P), (ii) HCV5aHi(T385) with reversion of T385P to T385, featuring the original E2 sequence determined in vivo and (iii) HCV5aHi(ΔHVR1) with deletion of HVR1. For these viruses, epitope exposure was investigated using human monoclonal (AR3A and AR4A) and polyclonal (C211 and H06) antibodies in neutralization assays. RESULTS Processed HCV5aHi formulated with AddaVax induced antibodies that efficiently bound homologous envelope proteins and broadly neutralized cultured genotype 1-6 HCV, with half maximal inhibitory concentrations of between 14 and 192 μg/ml (mean of 36 μg/ml against the homologous virus). Vaccination with aluminium hydroxide was less immunogenic. Compared to HCV5aHi(T385) with the original E2 sequence, HCV5aHi with a modified glycosylation site and HCV5aHi(ΔHVR1) without HVR1 showed increased neutralization epitope exposure but similar immunogenicity. CONCLUSION Using an adjuvant suitable for human use, we developed inactivated whole HCV vaccine candidates that induced broadly neutralizing antibodies, which warrant investigation in further pre-clinical studies. LAY SUMMARY A vaccine against hepatitis C virus (HCV) is needed to prevent the estimated 2 million new infections and 400,000 deaths caused by this virus each year. We developed inactivated whole HCV vaccine candidates using adjuvants licensed for human use, which, following immunization of mice, induced antibodies that efficiently neutralized all HCV genotypes with recognized epidemiological importance. HCV variants with modified envelope proteins exhibited similar immunogenicity as the virus with the original envelope proteins.
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Affiliation(s)
- Anne Finne Pihl
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital - Amager and Hvidovre, and Department of Immunology and Microbiolgy, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Shan Feng
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital - Amager and Hvidovre, and Department of Immunology and Microbiolgy, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Anna Offersgaard
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital - Amager and Hvidovre, and Department of Immunology and Microbiolgy, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Garazi Peña Alzua
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital - Amager and Hvidovre, and Department of Immunology and Microbiolgy, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Elias Honerød Augestad
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital - Amager and Hvidovre, and Department of Immunology and Microbiolgy, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Christian Kjaerulff Mathiesen
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital - Amager and Hvidovre, and Department of Immunology and Microbiolgy, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Tanja Bertelsen Jensen
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital - Amager and Hvidovre, and Department of Immunology and Microbiolgy, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Henrik Krarup
- Department of Molecular Diagnostics, Aalborg University Hospital and Clinical Institute, Aalborg University, Aalborg, Denmark
| | - Mansun Law
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, California, United States
| | - Jannick Prentoe
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital - Amager and Hvidovre, and Department of Immunology and Microbiolgy, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Jan Pravsgaard Christensen
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens Bukh
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital - Amager and Hvidovre, and Department of Immunology and Microbiolgy, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Judith Margarete Gottwein
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital - Amager and Hvidovre, and Department of Immunology and Microbiolgy, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
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Cano-Muñoz M, Lucas J, Lin LY, Cesaro S, Moog C, Conejero-Lara F. Conformational Stabilization of Gp41-Mimetic Miniproteins Opens Up New Ways of Inhibiting HIV-1 Fusion. Int J Mol Sci 2022; 23:2794. [PMID: 35269936 DOI: 10.3390/ijms23052794] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 02/22/2022] [Accepted: 02/28/2022] [Indexed: 12/20/2022] Open
Abstract
Inhibition of the HIV-1 fusion process constitutes a promising strategy to neutralize the virus at an early stage before it enters the cell. In this process, the envelope glycoprotein (Env) plays a central role by promoting membrane fusion. We previously identified a vulnerability at the flexible C-terminal end of the gp41 C-terminal heptad repeat (CHR) region to inhibition by a single-chain miniprotein (named covNHR-N) that mimics the first half of the gp41 N-terminal heptad repeat (NHR). The miniprotein exhibited low stability, moderate binding to its complementary CHR region, both as an isolated peptide and in native trimeric Envs, and low inhibitory activity against a panel of pseudoviruses. The addition of a disulfide bond stabilizing the miniprotein increased its inhibitory activity, without altering the binding affinity. Here, to further study the effect of conformational stability on binding and inhibitory potency, we additionally stabilized these miniproteins by engineering a second disulfide bond stapling their N-terminal end, The new disulfide-bond strongly stabilizes the protein, increases binding affinity for the CHR target and strongly improves inhibitory activity against several HIV-1 strains. Moreover, high inhibitory activity could be achieved without targeting the preserved hydrophobic pocket motif of gp41. These results may have implications in the discovery of new strategies to inhibit HIV targeting the gp41 CHR region.
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18
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Lu W, Li TW, Phillips S, Wu L. Reverted HIV-1 Mutants in CD4 + T-Cells Reveal Critical Residues in the Polar Region of Viral Envelope Glycoprotein. Microbiol Spectr 2021;:e0165321. [PMID: 34935422 DOI: 10.1128/spectrum.01653-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
HIV-1 envelope glycoprotein (Env) interacts with cell surface receptors and induces membrane fusion to enter cells and initiate infection. HIV-1 Env on virions comprises trimers of the gp120 and gp41 subunits. The polar region (PR) in the N-terminus of gp41 is composed of 17 conserved residues, including seven polar amino acids. We have reported that the PR is crucial for Env trimer stability and fusogenicity. Mutations of three highly conserved residues (S534P, T536A, or T538A) in the PR of HIV-1NL4-3 significantly decrease or eliminate viral infectivity due to defective fusion and increased gp120 shedding. To identify compensatory Env mutations that restore viral infectivity, we infected a CD4+ T-cell line with PR mutants pseudotyped with wild-type (WT) HIV-1 Env or vesicular stomatitis virus envelope glycoprotein (VSV-G). We found that PR mutant-infected CD4+ T-cells produced infectious viruses at 7 days postinfection (dpi). Sequencing of the env cDNA from cells infected with the recovered HIV-1 revealed that the S534P mutant reverted to serine or threonine at residue 534. Interestingly, the combined PR-mutant HIV-1 (S534P/T536A or S534P/T536A/T538A) recovered its infectivity and reverted to S534, but maintained the T536A or T538A mutation, suggesting that HIV-1 replication in CD4+ T-cells can tolerate T536A and T538A Env mutations, but not S534P. Moreover, VSV-G-pseudotyped HIV-1 mutants with a fusion-defective Env also recovered infectivity in CD4+ T-cells through reverted Env mutations. These new observations help define the Env residues critical for HIV-1 infection and demonstrate that Env-defective HIV-1 mutants can rapidly regain replication competency in CD4+ T-cells. IMPORTANCE Our previous mutagenesis study revealed that serine at position 534 of HIV-1 Env is critical for viral infectivity. We found that HIV-1 Env containing serine to proline mutation at position 534 (S534P) are incapable of supporting virus-cell and cell-cell fusion. To investigate whether these mutant viruses can recover infectivity and what amino acid changes account for recovered infectivity, we infected CD4+ T-cells with Env-mutant HIV-1 pseudotyped with WT HIV-1 Env or VSV-G and monitored cultures for the production of infectious viruses. Our results showed that most of the pseudotyped viruses recovered their infectivity within 1-week postinfection, and all the recovered viruses mutated proline at position 534. These observations help define the Env residues critical for HIV-1 replication. Because Env-defective HIV-1 mutants can rapidly regain replication competency in CD4+ T-cells, it is important to carefully monitor viral mutations for biosafety consideration when using HIV-1-derived lentivirus vectors pseudotyped with Env.
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19
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Zhang Y, Zheng S, Zhao W, Mao Y, Cao W, Zeng W, Liu Y, Hu L, Gong M, Cheng J, Chen Y, Yang H. Sequential Analysis of the N/O-Glycosylation of Heavily Glycosylated HIV-1 gp120 Using EThcD-sceHCD-MS/MS. Front Immunol 2021; 12:755568. [PMID: 34745128 PMCID: PMC8567067 DOI: 10.3389/fimmu.2021.755568] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 10/06/2021] [Indexed: 02/05/2023] Open
Abstract
Deciphering the glycosylation of the viral envelope (Env) glycoprotein is critical for evaluating viral escape from the host’s immune response and developing vaccines and antiviral drugs. However, it is still challenging to precisely decode the site-specific glycosylation characteristics of the highly glycosylated Env proteins, although glycoproteomics have made significant advances in mass spectrometry techniques and data analysis tools. Here, we present a hybrid dissociation technique, EThcD-sceHCD, by combining electron transfer/higher-energy collisional dissociation (EThcD) and stepped collision energy/higher-energy collisional dissociation (sceHCD) into a sequential glycoproteomic workflow. Following this scheme, we characterized site-specific N/O-glycosylation of the human immunodeficiency virus type 1 (HIV-1) Env protein gp120. The EThcD-sceHCD method increased the number of identified glycopeptides when compared with EThcD, while producing more comprehensive fragment ions than sceHCD for site-specific glycosylation analysis, especially for accurate O-glycosite assignment. Finally, eighteen N-glycosites and five O-glycosites with attached glycans were assigned unambiguously from heavily glycosylated gp120. These results indicate that our workflow can achieve improved performance for analysis of the N/O-glycosylation of a highly glycosylated protein containing numerous potential glycosites in one process. Knowledge of the glycosylation landscape of the Env glycoprotein will be useful for understanding of HIV-1 infection and development of vaccines and drugs.
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Affiliation(s)
- Yong Zhang
- National Health Commission (NHC) Key Laboratory of Transplant Engineering and Immunology, Institutes for Systems Genetics, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China.,Sichuan Provincial Engineering Laboratory of Pathology in Clinical Application, West China Hospital, Sichuan University, Chengdu, China
| | - Shanshan Zheng
- National Health Commission (NHC) Key Laboratory of Transplant Engineering and Immunology, Institutes for Systems Genetics, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Wanjun Zhao
- Department of Thoracic Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Yonghong Mao
- Institute of Thoracic Oncology, West China Hospital, Sichuan University, Chengdu, China
| | - Wei Cao
- National Health Commission (NHC) Key Laboratory of Transplant Engineering and Immunology, Institutes for Systems Genetics, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Wenjuan Zeng
- National Health Commission (NHC) Key Laboratory of Transplant Engineering and Immunology, Institutes for Systems Genetics, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Yueqiu Liu
- National Health Commission (NHC) Key Laboratory of Transplant Engineering and Immunology, Institutes for Systems Genetics, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Liqiang Hu
- National Health Commission (NHC) Key Laboratory of Transplant Engineering and Immunology, Institutes for Systems Genetics, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Meng Gong
- National Health Commission (NHC) Key Laboratory of Transplant Engineering and Immunology, Institutes for Systems Genetics, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China.,Sichuan Provincial Engineering Laboratory of Pathology in Clinical Application, West China Hospital, Sichuan University, Chengdu, China
| | - Jingqiu Cheng
- National Health Commission (NHC) Key Laboratory of Transplant Engineering and Immunology, Institutes for Systems Genetics, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Younan Chen
- National Health Commission (NHC) Key Laboratory of Transplant Engineering and Immunology, Institutes for Systems Genetics, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Hao Yang
- National Health Commission (NHC) Key Laboratory of Transplant Engineering and Immunology, Institutes for Systems Genetics, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China.,Sichuan Provincial Engineering Laboratory of Pathology in Clinical Application, West China Hospital, Sichuan University, Chengdu, China
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20
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Thomas AS, Moreau Y, Jiang W, Isaac JE, Ewing A, White LF, Kourtis AP, Sagar M. Pre-existing infant antibody-dependent cellular cytotoxicity associates with reduced HIV-1 acquisition and lower morbidity. Cell Rep Med 2021; 2:100412. [PMID: 34755132 PMCID: PMC8561235 DOI: 10.1016/j.xcrm.2021.100412] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 08/18/2021] [Accepted: 09/22/2021] [Indexed: 11/24/2022]
Abstract
In humans, pre-existing anti-HIV-1 neutralizing antibodies (nAbs) have not been associated with decreased HIV-1 acquisition. Here, we evaluate antibody-dependent cellular cytotoxicity (ADCC) present in pre-transmission infant and maternal plasma and breast milk (BM) against the contemporaneous maternal HIV-1 variants. HIV-1-exposed uninfected compared with HIV-1-exposed infected infants have higher ADCC and a combination of ADCC and nAb responses against their corresponding mother's strains. ADCC does not correlate with nAbs, suggesting they are independent activities. The infected infants with high ADCC compared with low ADCC, but not those with higher ADCC plus nAbs, have lower morbidity up to 1 year after birth. A higher IgA to IgG ratio, observed in BM supernatants and in a higher proportion of the infected compared with the uninfected infants, associates with lower ADCC. Against the exposure strains, ADCC, more than nAbs, associates with both lower mother-to-child transmission and decreased post-infection infant morbidity.
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Affiliation(s)
- Allison S Thomas
- Department of Microbiology, Boston University School of Medicine, Boston, MA, USA
| | - Yvetane Moreau
- Department of Medicine, Boston Medical Center, Boston, MA, USA
| | - Wenqing Jiang
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - John E Isaac
- Department of Medicine, Boston Medical Center, Boston, MA, USA
| | - Alexander Ewing
- Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Laura F White
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - Athena P Kourtis
- Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Manish Sagar
- Department of Medicine, Boston Medical Center, Boston, MA, USA
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21
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McCaul N, Quandte M, Bontjer I, van Zadelhoff G, Land A, Crooks ET, Binley JM, Sanders RW, Braakman I. Intramolecular quality control: HIV-1 envelope gp160 signal-peptide cleavage as a functional folding checkpoint. Cell Rep 2021; 36:109646. [PMID: 34469718 DOI: 10.1016/j.celrep.2021.109646] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 06/28/2021] [Accepted: 08/11/2021] [Indexed: 11/24/2022] Open
Abstract
Removal of the membrane-tethering signal peptides that target secretory proteins to the endoplasmic reticulum is a prerequisite for proper folding. While generally thought to be removed co-translationally, we report two additional post-targeting functions for the HIV-1 gp120 signal peptide, which remains attached until gp120 folding triggers its removal. First, the signal peptide improves folding fidelity by enhancing conformational plasticity of gp120 by driving disulfide isomerization through a redox-active cysteine. Simultaneously, the signal peptide delays folding by tethering the N terminus to the membrane, until assembly with the C terminus. Second, its carefully timed cleavage represents intramolecular quality control and ensures release of (only) natively folded gp120. Postponed cleavage and the redox-active cysteine are both highly conserved and important for viral fitness. Considering the ∼15% proteins with signal peptides and the frequency of N-to-C contacts in protein structures, these regulatory roles of signal peptides are bound to be more common in secretory-protein biogenesis.
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Affiliation(s)
- Nicholas McCaul
- Cellular Protein Chemistry, Bijvoet Center for Biomolecular Research, Science4Life, Faculty of Science, Utrecht University, Padualaan 8, 3584 Utrecht, the Netherlands
| | - Matthias Quandte
- Cellular Protein Chemistry, Bijvoet Center for Biomolecular Research, Science4Life, Faculty of Science, Utrecht University, Padualaan 8, 3584 Utrecht, the Netherlands
| | - Ilja Bontjer
- Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam Institute for Infection and Immunity, 1105 Amsterdam, the Netherlands
| | - Guus van Zadelhoff
- Cellular Protein Chemistry, Bijvoet Center for Biomolecular Research, Science4Life, Faculty of Science, Utrecht University, Padualaan 8, 3584 Utrecht, the Netherlands
| | - Aafke Land
- Cellular Protein Chemistry, Bijvoet Center for Biomolecular Research, Science4Life, Faculty of Science, Utrecht University, Padualaan 8, 3584 Utrecht, the Netherlands
| | - Ema T Crooks
- San Diego Biomedical Research Institute, 10865 Road to the Cure #100, San Diego, CA, USA
| | - James M Binley
- San Diego Biomedical Research Institute, 10865 Road to the Cure #100, San Diego, CA, USA
| | - Rogier W Sanders
- Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam Institute for Infection and Immunity, 1105 Amsterdam, the Netherlands; Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, NY 10021, USA
| | - Ineke Braakman
- Cellular Protein Chemistry, Bijvoet Center for Biomolecular Research, Science4Life, Faculty of Science, Utrecht University, Padualaan 8, 3584 Utrecht, the Netherlands.
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22
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Rajashekar JK, Richard J, Beloor J, Prévost J, Anand SP, Beaudoin-Bussières G, Shan L, Herndler-Brandstetter D, Gendron-Lepage G, Medjahed H, Bourassa C, Gaudette F, Ullah I, Symmes K, Peric A, Lindemuth E, Bibollet-Ruche F, Park J, Chen HC, Kaufmann DE, Hahn BH, Sodroski J, Pazgier M, Flavell RA, Smith AB, Finzi A, Kumar P. Modulating HIV-1 envelope glycoprotein conformation to decrease the HIV-1 reservoir. Cell Host Microbe 2021; 29:904-916.e6. [PMID: 34019804 PMCID: PMC8214472 DOI: 10.1016/j.chom.2021.04.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 02/01/2021] [Accepted: 04/20/2021] [Indexed: 11/21/2022]
Abstract
Small CD4-mimetic compounds (CD4mc) sensitize HIV-1-infected cells to antibody-dependent cellular cytotoxicity (ADCC) by facilitating antibody recognition of epitopes that are otherwise occluded on the unliganded viral envelope (Env). Combining CD4mc with two families of CD4-induced (CD4i) antibodies, which are frequently found in plasma of HIV-1-infected individuals, stabilizes Env in a conformation that is vulnerable to ADCC. We employed new-generation SRG-15 humanized mice, supporting natural killer (NK) cell and Fc-effector functions to demonstrate that brief treatment with CD4mc and CD4i-Abs significantly decreases HIV-1 replication, the virus reservoir and viral rebound after ART interruption. These effects required Fc-effector functions and NK cells, highlighting the importance of ADCC. Viral rebound was also suppressed in HIV-1+-donor cell-derived humanized mice supplemented with autologous HIV-1+-donor-derived plasma and CD4mc. These results indicate that CD4mc could have therapeutic utility in infected individuals for decreasing the size of the HIV-1 reservoir and/or achieving a functional cure.
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Affiliation(s)
- Jyothi K Rajashekar
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Jonathan Richard
- Centre de Recherche du CHUM, Montreal, QC, Canada; Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Canada
| | - Jagadish Beloor
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Jérémie Prévost
- Centre de Recherche du CHUM, Montreal, QC, Canada; Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Canada
| | - Sai Priya Anand
- Centre de Recherche du CHUM, Montreal, QC, Canada; Department of Microbiology and Immunology, McGill University Montreal, Montreal, QC, Canada
| | - Guillaume Beaudoin-Bussières
- Centre de Recherche du CHUM, Montreal, QC, Canada; Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Canada
| | - Liang Shan
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT, USA
| | | | | | | | | | | | - Irfan Ullah
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Kelly Symmes
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Andrew Peric
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Emily Lindemuth
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Frederic Bibollet-Ruche
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Jun Park
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA, USA
| | - Hung-Ching Chen
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA, USA
| | - Daniel E Kaufmann
- Centre de Recherche du CHUM, Montreal, QC, Canada; Department of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Beatrice H Hahn
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Joseph Sodroski
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, and Department of Microbiology and Immunobiology, Division of AIDS, Harvard Medical School, Boston, MA, USA; Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, MA, USA
| | - Marzena Pazgier
- Infectious Diseases Division, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Richard A Flavell
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT, USA.
| | - Amos B Smith
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA, USA.
| | - Andrés Finzi
- Centre de Recherche du CHUM, Montreal, QC, Canada; Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Canada; Department of Microbiology and Immunology, McGill University Montreal, Montreal, QC, Canada.
| | - Priti Kumar
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA.
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Russell CJ, Hurwitz JL. Sendai Virus-Vectored Vaccines That Express Envelope Glycoproteins of Respiratory Viruses. Viruses 2021; 13:1023. [PMID: 34072332 DOI: 10.3390/v13061023] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 05/10/2021] [Accepted: 05/21/2021] [Indexed: 01/01/2023] Open
Abstract
Human respiratory syncytial virus (HRSV), human metapneumovirus (HMPV), and human parainfluenza viruses (HPIVs) are leading causes of respiratory disease in young children, the elderly, and individuals of all ages with immunosuppression. Vaccination strategies against these pneumoviruses and paramyxoviruses are vast in number, yet no licensed vaccines are available. Here, we review development of Sendai virus (SeV), a versatile pediatric vaccine that can (a) serve as a Jennerian vaccine against HPIV1, (b) serve as a recombinant vaccine against HRSV, HPIV2, HPIV3, and HMPV, (c) accommodate foreign genes for viral glycoproteins in multiple intergenic positions, (d) induce durable, mucosal, B-cell, and T-cell immune responses without enhanced immunopathology, (e) protect cotton rats, African green monkeys, and chimpanzees from infection, and (f) be formulated into a vaccine cocktail. Clinical phase I safety trials of SeV have been completed in adults and 3–6-year-old children. Clinical testing of SeVRSV, an HRSV fusion (F) glycoprotein gene recombinant, has also been completed in adults. Positive results from these studies, and collaborative efforts with the National Institutes of Health and the Serum Institute of India assist advanced development of SeV-based vaccines. Prospects are now good for vaccine successes in infants and consequent protection against serious viral disease.
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Li H, Wang S, Hu G, Zhang L, Liu S, Lu S. DNA priming immunization is more effective than recombinant protein vaccine in eliciting antigen-specific B cell responses. Emerg Microbes Infect 2021; 10:833-841. [PMID: 33853515 PMCID: PMC8812797 DOI: 10.1080/22221751.2021.1918026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
While DNA prime-protein boost vaccination approach has been widely used in preclinical and clinical studies especially in the field of HIV vaccine development, the exact role of DNA immunization has not been fully identified. Our previous work demonstrated that DNA immunization was able to elicit T follicular helper (Tfh) cell responses and germinal center (GC) B cell development in a mouse model. In the current report, a mouse immunogenicity study was conducted to further ask whether DNA immunization is able to elicit antigen-specific B cell responses. Using HIV-1 Env as model antigen delivered in the form of DNA prime-protein boost, our data demonstrated that DNA prime was able to enhance the antigen-specific B cell responses for both Env-specific antibody secreting cells (ASC) and memory B cells. Furthermore, the DNA priming can greatly reduce the need of including an adjuvant as part of the recombinant protein vaccine boost formulation. Our findings revealed one mechanism that supports the value of DNA priming in assisting the inductin of high affinity and long lasting antigen specific antibody responses.
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Affiliation(s)
- Haiying Li
- Laboratory of Nucleic Acid Vaccines, Department of Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Shixia Wang
- Laboratory of Nucleic Acid Vaccines, Department of Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Guangnan Hu
- Laboratory of Nucleic Acid Vaccines, Department of Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Lu Zhang
- Department of General Surgery, The First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China
| | | | - Shan Lu
- Laboratory of Nucleic Acid Vaccines, Department of Medicine, University of Massachusetts Medical School, Worcester, MA, USA
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Abstract
HIV-1 (human immunodeficiency virus type 1) infection begins with the attachment of the virion to a host cell by its envelope glycoprotein (Env), which subsequently induces fusion of viral and cell membranes to allow viral entry. Upon binding to primary receptor CD4 and coreceptor (e.g., chemokine receptor CCR5 or CXCR4), Env undergoes large conformational changes and unleashes its fusogenic potential to drive the membrane fusion. The structural biology of HIV-1 Env and its complexes with the cellular receptors not only has advanced our knowledge of the molecular mechanism of how HIV-1 enters the host cells but also provided a structural basis for the rational design of fusion inhibitors as potential antiviral therapeutics. In this review, we summarize our latest understanding of the HIV-1 membrane fusion process and discuss related therapeutic strategies to block viral entry.
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Cano-Muñoz M, Cesaro S, Morel B, Lucas J, Moog C, Conejero-Lara F. Extremely Thermostabilizing Core Mutations in Coiled-Coil Mimetic Proteins of HIV-1 gp41 Produce Diverse Effects on Target Binding but Do Not Affect Their Inhibitory Activity. Biomolecules 2021; 11:566. [PMID: 33921495 DOI: 10.3390/biom11040566] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 04/05/2021] [Accepted: 04/09/2021] [Indexed: 11/16/2022] Open
Abstract
A promising strategy to neutralize HIV-1 is to target the gp41 spike subunit to block membrane fusion with the cell. We previously designed a series of single-chain proteins (named covNHR) that mimic the trimeric coiled-coil structure of the gp41 N-terminal heptad repeat (NHR) region and potently inhibit HIV-1 cell infection by avidly binding the complementary C-terminal heptad repeat (CHR) region. These proteins constitute excellent tools to understand the structural and thermodynamic features of this therapeutically important interaction. Gp41, as with many coiled-coil proteins, contains in core positions of the NHR trimer several highly conserved, buried polar residues, the role of which in gp41 structure and function is unclear. Here we produced three covNHR mutants by substituting each triad of polar residues for the canonical isoleucine. The mutants preserve their helical structure and show an extremely increased thermal stability. However, increased hydrophobicity enhances their self-association. Calorimetric analyses show a marked influence of mutations on the binding thermodynamics of CHR-derived peptides. The mutations do not affect however the in vitro HIV-1 inhibitory activity of the proteins. The results support a role of buried core polar residues in maintaining structural uniqueness and promoting an energetic coupling between conformational stability and NHR-CHR binding.
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Zhang P, Kwon AL, Guzzo C, Liu Q, Schmeisser H, Miao H, Lin Y, Cimbro R, Huang J, Connors M, Schmidt SD, Dolan MA, Armstrong AA, Lusso P. Functional Anatomy of the Trimer Apex Reveals Key Hydrophobic Constraints That Maintain the HIV-1 Envelope Spike in a Closed State. mBio 2021; 12:e00090-21. [PMID: 33785631 DOI: 10.1128/mBio.00090-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Elucidating the structure and function of the HIV-1 outer envelope proteins is critical for the design of an effective vaccine. Despite the availability of many high-resolution structures, key functional correlates in the envelope trimer remain undefined. The human immunodeficiency virus type 1 (HIV-1) envelope trimer maintains a closed, metastable configuration to protect vulnerable epitopes from neutralizing antibodies. Here, we identify key hydrophobic constraints at the trimer apex that function as global stabilizers of the HIV-1 envelope spike configuration. Mutation of individual residues within four hydrophobic clusters that fasten together the V1V2, V3, and C4 domains at the apex of gp120 dramatically increases HIV-1 sensitivity to weak and restricted neutralizing antibodies targeting epitopes that are largely concealed in the prefusion Env spike, consistent with the adoption of a partially open trimer configuration. Conversely, the same mutations decrease the sensitivity to broad and potent neutralizing antibodies that preferentially recognize the closed trimer. Sera from chronically HIV-infected patients neutralize open mutants with enhanced potency, compared to the wild-type virus, suggesting that a large fraction of host-generated antibodies target concealed epitopes. The identification of structural constraints that maintain the HIV-1 envelope in an antibody-protected state may inform the design of a protective vaccine.
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Arachchige SP, Henke W, Kalamvoki M, Stephens EB. Structural Domains of the Herpes Simplex Type 1 gD Protein that Restrict HIV-1 Particle Infectivity. J Virol 2021; 95:JVI. [PMID: 33536165 DOI: 10.1128/JVI.02355-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Previously, we showed that the presence of the herpes simplex virus type 1 (HSV-1) gD glycoprotein but not gB potently restricted HIV-1 particle infectivity. This restriction was characterized by incorporation of HSV-1 gD and the exclusion of the HIV-1 gp120/gp41 from budding virus particles. To determine the structural domains involved in gD restriction of HIV-1, a series of deletion mutants and chimeric proteins between gD and the non-restrictive gB were generated. Our results show that deletion of the cytoplasmic tail domain (CTD) of gD or that replacement of the transmembrane domain (TMD) with the TMD from gB slightly reduced restriction activity. However, replacement of the gD CTD with that of gB resulted in lower cell surface expression, significantly less incorporation into HIV-1 particles, and inefficient restriction of the release of infectious HIV-1. Analysis of gB/gD chimeric proteins revealed that removal of the gB CTD or replacement with gD CTD resulted in enhanced surface expression and an increase in restriction activity. Finally, we show that expression of gD without other HSV-1 proteins resulted in gD fractionation into detergent resistant membranes (DRM) and that gD co-localized with the raft marker GM1, which may partially explain its incorporation into budding virus particles. Taken together, our results suggest that expression of gD at the cell surface is likely a major factor but that other intrinsic properties are also involved in the gD-mediated restriction of HIV-1 particle infectivity.IMPORTANCE Previously, we showed that unlike the HSV-1, the presence of the gD glycoprotein in virus producer cells but not gB potently restricted HIV-1 particle infectivity. To better understand the relationship between cell surface expression, virus incorporation and restriction of HIV-1, we analyzed a series of deletion mutants and chimeric proteins in which domains of gD and gB were swapped. Our results indicate that: a) gD/gB chimeras having the cytoplasmic domain (CTD) of gB significantly reduced cell surface expression, release from cells, incorporation into virus, and reduced HIV-1 restriction; b) removal of the gB CTD or replacement with the gD CTD resulted in better surface expression, incorporation into HIV-1, and enhanced restriction; and c) the transmembrane domain of gB can influence transport and ultimately effect incorporation of gB into HIV-1. Overall, these data support a role for gD surface expression as crucial to restriction of infectious HIV-1 release.
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Cheliout Da Silva S, Yan L, Dang HV, Xu K, Epstein JH, Veesler D, Broder CC. Functional Analysis of the Fusion and Attachment Glycoproteins of Mojiang Henipavirus. Viruses 2021; 13:517. [PMID: 33809833 DOI: 10.3390/v13030517] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Revised: 03/16/2021] [Accepted: 03/17/2021] [Indexed: 01/30/2023] Open
Abstract
Mojiang virus (MojV) is the first henipavirus identified in a rodent and known only by sequence data, whereas all other henipaviruses have been isolated from bats (Hendra virus, Nipah virus, Cedar virus) or discovered by sequence data from material of bat origin (Ghana virus). Ephrin-B2 and -B3 are entry receptors for Hendra and Nipah viruses, but Cedar virus can utilize human ephrin-B1, -B2, -A2 and -A5 and mouse ephrin-A1. However, the entry receptor for MojV remains unknown, and its species tropism is not well characterized. Here, we utilized recombinant full-length and soluble forms of the MojV fusion (F) and attachment (G) glycoproteins in membrane fusion and receptor tropism studies. MojV F and G were functionally competent and mediated cell–cell fusion in primate and rattine cells, albeit with low levels and slow fusion kinetics. Although a relative instability of the pre-fusion conformation of a soluble form of MojV F was observed, MojV F displayed significantly greater fusion activity when heterotypically paired with Ghana virus G. An exhaustive investigation of A- and B-class ephrins indicated that none serve as a primary receptor for MojV. The MojV cell fusion phenotype is therefore likely the result of receptor restriction rather than functional defects in recombinant MojV F and G glycoproteins.
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Cui X, Cao Z, Ishikawa Y, Cui S, Imadome KI, Snapper CM. Immunization with Epstein-Barr Virus Core Fusion Machinery Envelope Proteins Elicit High Titers of Neutralizing Activities and Protect Humanized Mice from Lethal Dose EBV Challenge. Vaccines (Basel) 2021; 9:285. [PMID: 33808755 DOI: 10.3390/vaccines9030285] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 02/26/2021] [Accepted: 03/11/2021] [Indexed: 12/18/2022] Open
Abstract
Epstein–Barr virus (EBV) is the primary cause of infectious mononucleosis and is strongly implicated in the etiology of multiple lymphoid and epithelial cancers. EBV core fusion machinery envelope proteins gH/gL and gB coordinately mediate EBV fusion and entry into its target cells, B lymphocytes and epithelial cells, suggesting these proteins could induce antibodies that prevent EBV infection. We previously reported that the immunization of rabbits with recombinant EBV gH/gL or trimeric gB each induced markedly higher serum EBV-neutralizing titers for B lymphocytes than that of the leading EBV vaccine candidate gp350. In this study, we demonstrated that immunization of rabbits with EBV core fusion machinery proteins induced high titer EBV neutralizing antibodies for both B lymphocytes and epithelial cells, and EBV gH/gL in combination with EBV trimeric gB elicited strong synergistic EBV neutralizing activities. Furthermore, the immune sera from rabbits immunized with EBV gH/gL or trimeric gB demonstrated strong passive immune protection of humanized mice from lethal dose EBV challenge, partially or completely prevented death respectively, and markedly decreased the EBV load in peripheral blood of humanized mice. These data strongly suggest the combination of EBV core fusion machinery envelope proteins gH/gL and trimeric gB is a promising EBV prophylactic vaccine.
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Meuleman TJ, Cowton VM, Patel AH, Liskamp RMJ. Design and Synthesis of HCV-E2 Glycoprotein Epitope Mimics in Molecular Construction of Potential Synthetic Vaccines. Viruses 2021; 13:v13020326. [PMID: 33672697 PMCID: PMC7924389 DOI: 10.3390/v13020326] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/10/2021] [Accepted: 02/13/2021] [Indexed: 12/30/2022] Open
Abstract
Hepatitis C virus remains a global threat, despite the availability of highly effective direct-acting antiviral (DAA) drugs. With thousands of new infections annually, the need for a prophylactic vaccine is evident. However, traditional vaccine design has been unable to provide effective vaccines so far. Therefore, alternative strategies need to be investigated. In this work, a chemistry-based approach is explored towards fully synthetic peptide-based vaccines using epitope mimicry, by focusing on highly effective and conserved amino acid sequences in HCV, which, upon antibody binding, inhibit its bio-activity. Continuous and discontinuous epitope mimics were both chemically synthesized based on the HCV-E2 glycoprotein while using designed fully synthetic cyclic peptides. These cyclic epitope mimics were assembled on an orthogonally protected scaffold. The scaffolded epitope mimics have been assessed in immunization experiments to investigate the elicitation of anti-HCV-E2 glycoprotein antibodies. The neutralizing potential of the elicited antibodies was investigated, representing a first step in employing chemically synthesized epitope mimics as a novel strategy towards vaccine design.
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Affiliation(s)
- Theodorus J. Meuleman
- School of Chemistry, University of Glasgow, Joseph Black Building, University Avenue, Glasgow G12 8QQ, UK;
- Enzytag, Daelderweg, 9 6361 HK Nuth, The Netherlands
| | - Vanessa M. Cowton
- MRC-University of Glasgow Centre for Virus Research, Garscube Campus, Sir Michael Stoker Building, 464 Bearsden Road, Glasgow G61 1QH, UK;
| | - Arvind H. Patel
- MRC-University of Glasgow Centre for Virus Research, Garscube Campus, Sir Michael Stoker Building, 464 Bearsden Road, Glasgow G61 1QH, UK;
- Correspondence: (A.H.P.); (R.M.J.L.)
| | - Rob M. J. Liskamp
- School of Chemistry, University of Glasgow, Joseph Black Building, University Avenue, Glasgow G12 8QQ, UK;
- Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Faculty of Health, Medicine and Life Sciences, Maastricht UMC, Universiteitssingel 50, 6229 ER Maastricht, The Netherlands
- Chemical Biology and Drug Discovery, Department of Pharmaceutics, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
- Cristal Therapeutics, Oxfordlaan 55, 6229 EV Maastricht, The Netherlands
- Correspondence: (A.H.P.); (R.M.J.L.)
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Drouin A, Migraine J, Durand MA, Moreau A, Burlaud-Gaillard J, Beretta M, Roingeard P, Bouvin-Pley M, Braibant M. Escape of HIV-1 envelope glycoprotein from the restriction of infection by IFITM3. J Virol 2021; 95:JVI. [PMID: 33298540 DOI: 10.1128/JVI.01994-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Interferon-induced transmembrane protein 3 (IFITM3) is a cellular factor that reduces HIV-1 infectivity by an incompletely understood mechanism. We show here that viruses differing only in the envelope glycoprotein (Env) expressed on their surface have different sensitivities to IFITM3. Measurements of the sensitivity of viruses to neutralizing antibodies showed that IFITM3 increased the sensitivity of IFITM3-sensitive viruses to PG16, which targets the V1V2 loop, suggesting that IFITM3 promotes exposure of the PG16 epitope of IFITM3-sensitive viruses. Exchanges of V1V2 loops between the Env proteins of sensitive and resistant viruses revealed that V1V2 and V3 act together to modulate viral sensitivity to IFITM3. Co-immunoprecipitation experiments showed that IFITM3 interacted with both the precursor (gp160) and cleaved (gp120) forms of Env from IFITM3-sensitive viruses, but only with the precursor (gp160) form of Env from IFITM3-resistant viruses. This finding suggests that the interaction between the Env of resistant viruses and IFITM3 was inhibited once Env had been processed in the Golgi apparatus. This hypothesis was supported by immunofluorescence experiments, which showed a strong colocalization of IFITM3 with the Env of sensitive viruses, but only weak colocalization with the Env of resistant viruses on the plasma membrane of virus-producing cells. Together, these results indicate that IFITM3 interacts with Env, inducing conformational changes that may decrease viral infectivity. This antiviral action is, nevertheless, modulated by the nature of the Env, in particular its V1V2 and V3 loops, which after maturation may be able to escape this interaction.IMPORTANCE Interferon-induced transmembrane protein 3 (IFITM3) is a cellular factor that reduces HIV-1 infectivity by an incompletely understood mechanism. This study aimed to elucidate the role of the HIV-1 envelope glycoprotein (Env) in determining viral susceptibility to IFITM3. We found that viruses differing only in Env expressed on their surface had different sensitivities to IFITM3. By comparing the Env proteins of viruses that were highly sensitive or resistant to IFITM3, we obtained new insight in the mechanisms by which HIV-1 escapes this protein. We showed that IFITM3 interacts with the Env protein of sensitive viruses in virion-producing cells, inducing conformational changes that may decrease viral infectivity. However, this antiviral action is modulated by the nature of Env, particularly the V1V2 and V3 loops, which may be able to escape this interaction after processing in the Golgi.
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Guest JD, Wang R, Elkholy KH, Chagas A, Chao KL, Cleveland TE, Kim YC, Keck ZY, Marin A, Yunus AS, Mariuzza RA, Andrianov AK, Toth EA, Foung SKH, Pierce BG, Fuerst TR. Design of a native-like secreted form of the hepatitis C virus E1E2 heterodimer. Proc Natl Acad Sci U S A 2021; 118:e2015149118. [PMID: 33431677 PMCID: PMC7826332 DOI: 10.1073/pnas.2015149118] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Hepatitis C virus (HCV) is a major worldwide health burden, and a preventive vaccine is needed for global control or eradication of this virus. A substantial hurdle to an effective HCV vaccine is the high variability of the virus, leading to immune escape. The E1E2 glycoprotein complex contains conserved epitopes and elicits neutralizing antibody responses, making it a primary target for HCV vaccine development. However, the E1E2 transmembrane domains that are critical for native assembly make it challenging to produce this complex in a homogenous soluble form that is reflective of its state on the viral envelope. To enable rational design of an E1E2 vaccine, as well as structural characterization efforts, we have designed a soluble, secreted form of E1E2 (sE1E2). As with soluble glycoprotein designs for other viruses, it incorporates a scaffold to enforce assembly in the absence of the transmembrane domains, along with a furin cleavage site to permit native-like heterodimerization. This sE1E2 was found to assemble into a form closer to its expected size than full-length E1E2. Preservation of native structural elements was confirmed by high-affinity binding to a panel of conformationally specific monoclonal antibodies, including two neutralizing antibodies specific to native E1E2 and to its primary receptor, CD81. Finally, sE1E2 was found to elicit robust neutralizing antibodies in vivo. This designed sE1E2 can both provide insights into the determinants of native E1E2 assembly and serve as a platform for production of E1E2 for future structural and vaccine studies, enabling rational optimization of an E1E2-based antigen.
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Affiliation(s)
- Johnathan D Guest
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742
| | - Ruixue Wang
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
| | - Khadija H Elkholy
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
- Molecular Biology Department, Genetic Engineering and Biotechnology Division, National Research Centre, Cairo 12622, Egypt
| | - Andrezza Chagas
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
| | - Kinlin L Chao
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742
| | - Thomas E Cleveland
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
- Biomolecular Measurement Division, National Institute of Standards and Technology, Gaithersburg, MD 20899
| | - Young Chang Kim
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305
| | - Zhen-Yong Keck
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305
| | - Alexander Marin
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
| | - Abdul S Yunus
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
| | - Roy A Mariuzza
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742
| | - Alexander K Andrianov
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
| | - Eric A Toth
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
| | - Steven K H Foung
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305
| | - Brian G Pierce
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850;
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742
| | - Thomas R Fuerst
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850;
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742
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Hikichi Y, Van Duyne R, Pham P, Groebner JL, Wiegand A, Mellors JW, Kearney MF, Freed EO. Mechanistic Analysis of the Broad Antiretroviral Resistance Conferred by HIV-1 Envelope Glycoprotein Mutations. mBio 2021; 12:e03134-20. [PMID: 33436439 DOI: 10.1128/mBio.03134-20] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Although combination antiretroviral (ARV) therapy is highly effective in controlling the progression of HIV disease, drug resistance can be a major obstacle. Recent findings suggest that resistance can develop without ARV target gene mutations. Despite the effectiveness of antiretroviral (ARV) therapy, virological failure can occur in some HIV-1-infected patients in the absence of mutations in drug target genes. We previously reported that, in vitro, the lab-adapted HIV-1 NL4-3 strain can acquire resistance to the integrase inhibitor dolutegravir (DTG) by acquiring mutations in the envelope glycoprotein (Env) that enhance viral cell-cell transmission. In this study, we investigated whether Env-mediated drug resistance extends to ARVs other than DTG and whether it occurs in other HIV-1 isolates. We demonstrate that Env mutations can reduce susceptibility to multiple classes of ARVs and also increase resistance to ARVs when coupled with target-gene mutations. We observe that the NL4-3 Env mutants display a more stable and closed Env conformation and lower rates of gp120 shedding than the WT virus. We also selected for Env mutations in clinically relevant HIV-1 isolates in the presence of ARVs. These Env mutants exhibit reduced susceptibility to DTG, with effects on replication and Env structure that are HIV-1 strain dependent. Finally, to examine a possible in vivo relevance of Env-mediated drug resistance, we performed single-genome sequencing of plasma-derived virus from five patients failing an integrase inhibitor-containing regimen. This analysis revealed the presence of several mutations in the highly conserved gp120-gp41 interface despite low frequency of resistance mutations in integrase. These results suggest that mutations in Env that enhance the ability of HIV-1 to spread via a cell-cell route may increase the opportunity for the virus to acquire high-level drug resistance mutations in ARV target genes.
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Chai K, Wang Z, Xu Y, Zhang J, Tan J, Qiao W. Palmitoylation of the Bovine Foamy Virus Envelope Glycoprotein Is Required for Viral Replication. Viruses 2020; 13:v13010031. [PMID: 33375397 PMCID: PMC7824066 DOI: 10.3390/v13010031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 12/19/2020] [Accepted: 12/23/2020] [Indexed: 12/27/2022] Open
Abstract
Membrane proteins of enveloped viruses have been reported to undergo palmitoylation, a post-translational modification often having a critical role in the function of these viral proteins and hence viral replication. In this study, we report that the foamy virus (FV) envelope (Env) glycoprotein is palmitoylated. Specifically, we found that bovine foamy virus (BFV) Env (BEnv) is palmitoylated at amino acid positions C58 and C59 by BDHHC3 and BDHHC20 in a DHHC motif-dependent manner. In addition, mutations C58S and C58/59S significantly decrease cell surface expression of BEnv, subviral particle (SVP) egress, and its membrane fusion activity, thus ultimately inhibiting BFV replication. The C59S mutation exerts a minor effect in this regard. Taken together, these data demonstrate that the function of BEnv in the context of BFV replication is under the regulation of palmitoylation.
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Affiliation(s)
| | | | | | | | | | - Wentao Qiao
- Correspondence: ; Tel.: +86-22-2350-4547; Fax: +86-22-2350-0950
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Dupont A, Glück IM, Ponti D, Stirnnagel K, Hütter S, Perrotton F, Stanke N, Richter S, Lindemann D, Lamb DC. Identification of an Intermediate Step in Foamy Virus Fusion. Viruses 2020; 12:v12121472. [PMID: 33371254 PMCID: PMC7766700 DOI: 10.3390/v12121472] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 12/13/2020] [Accepted: 12/17/2020] [Indexed: 12/20/2022] Open
Abstract
Viral glycoprotein-mediated membrane fusion is an essential step for productive infection of host cells by enveloped viruses; however, due to its rarity and challenges in detection, little is known about the details of fusion events at the single particle level. Here, we have developed dual-color foamy viruses (FVs) composed of eGFP-tagged prototype FV (PFV) Gag and mCherry-tagged Env of either PFV or macaque simian FV (SFVmac) origin that have been optimized for detection of the fusion process. Using our recently developed tracking imaging correlation (TrIC) analysis, we were able to detect the fusion process for both PFV and SFVmac Env containing virions. PFV Env-mediated fusion was observed both at the plasma membrane as well as from endosomes, whereas SFVmac Env-mediated fusion was only observed from endosomes. PFV Env-mediated fusion was observed to happen more often and more rapidly than as for SFVmac Env. Strikingly, using the TrIC method, we detected a novel intermediate state where the envelope and capsids are still tethered but separated by up to 400 nm before final separation of Env and Gag occurred.
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Affiliation(s)
- Aurélie Dupont
- Department of Chemistry, Ludwig Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany; (A.D.); (I.M.G.); (D.P.); (F.P.)
- Center for Nano Science (CENS), Ludwig Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany
- LIPhy, University Grenoble Alpes, CNRS, F-38000 Grenoble, France
| | - Ivo M. Glück
- Department of Chemistry, Ludwig Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany; (A.D.); (I.M.G.); (D.P.); (F.P.)
- Center for Nano Science (CENS), Ludwig Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany
| | - Dorothee Ponti
- Department of Chemistry, Ludwig Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany; (A.D.); (I.M.G.); (D.P.); (F.P.)
- Center for Nano Science (CENS), Ludwig Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany
| | - Kristin Stirnnagel
- Medical Faculty “Carl Gustav Carus”, Institute of Virology, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany; (K.S.); (S.H.); (N.S.); (S.R.)
- CRTD/DFG-Center for Regenerative Therapies, Technische Universität Dresden, Fetscherstr. 105, 01307 Dresden, Germany
| | - Sylvia Hütter
- Medical Faculty “Carl Gustav Carus”, Institute of Virology, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany; (K.S.); (S.H.); (N.S.); (S.R.)
- CRTD/DFG-Center for Regenerative Therapies, Technische Universität Dresden, Fetscherstr. 105, 01307 Dresden, Germany
| | - Florian Perrotton
- Department of Chemistry, Ludwig Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany; (A.D.); (I.M.G.); (D.P.); (F.P.)
| | - Nicole Stanke
- Medical Faculty “Carl Gustav Carus”, Institute of Virology, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany; (K.S.); (S.H.); (N.S.); (S.R.)
- CRTD/DFG-Center for Regenerative Therapies, Technische Universität Dresden, Fetscherstr. 105, 01307 Dresden, Germany
| | - Stefanie Richter
- Medical Faculty “Carl Gustav Carus”, Institute of Virology, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany; (K.S.); (S.H.); (N.S.); (S.R.)
- CRTD/DFG-Center for Regenerative Therapies, Technische Universität Dresden, Fetscherstr. 105, 01307 Dresden, Germany
| | - Dirk Lindemann
- Medical Faculty “Carl Gustav Carus”, Institute of Virology, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany; (K.S.); (S.H.); (N.S.); (S.R.)
- CRTD/DFG-Center for Regenerative Therapies, Technische Universität Dresden, Fetscherstr. 105, 01307 Dresden, Germany
- Correspondence: (D.L.); (D.C.L.)
| | - Don C. Lamb
- Department of Chemistry, Ludwig Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany; (A.D.); (I.M.G.); (D.P.); (F.P.)
- Center for Nano Science (CENS), Ludwig Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany
- Nanosystems Initiative München (NIM), Ludwig Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany
- Center for Integrated Protein Science (CIPSM), Ludwig Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany
- Correspondence: (D.L.); (D.C.L.)
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Chen J, Li J, Li L, Liu P, Xiang Y, Cao W. Single Amino Acids G196 and R198 in hr1 of Subgroup K Avian Leukosis Virus Glycoprotein Are Critical for Tva Receptor Binding. Front Microbiol 2020; 11:596586. [PMID: 33391214 PMCID: PMC7772352 DOI: 10.3389/fmicb.2020.596586] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 11/13/2020] [Indexed: 11/13/2022] Open
Abstract
Avian leukosis viruses (ALVs), a type of retrovirus responsible for various tumor diseases in chickens, are divided into 11 subgroups: ALV-A to ALV-K. After the envelope glycoproteins of ALV interact with the cellular receptor to initiate viral invasion, alterations in a few amino acids of the viral glycoproteins or cell receptors may trigger changes in their conformation and binding affinity. To identify the functional determinants of the ALV-K envelope protein that binds to Tva (a recently identified cellular receptor of ALV-K), using the strategy of continuous, segment-by-segment substitution of the gp85-encoded surface glycoprotein (SU) of ALV-K GDFX0602 with ALV-E ev-1 (using Tvb as the receptor), a series of chimeric soluble gp85 proteins were expressed for co-immunoprecipitation (co-IP) analysis and a series of recombinant viruses with replication-competent avian retrovirus vectors containing Bryan polymerase (RCASBP) as their skeleton were created for transfecting to DF-1 cells and titer determination. The co-IP analysis, fluorescence-activated cell sorting, and virus titer measurements revealed that the substitution of residues 194–198, 206–216 of hr1, residues 251–256 between hr1 and hr2, and residues 269–280 of hr2 were identified to reduce the binding of gp85 to Tva. The substitution of residues 194–221 in hr1 nullified the infectiveness of these viruses, similar to the effect of single amino acid mutations in K251E and L252I located between hr1 and hr2; continuous amino acid mutations in hr2 could not produce the same effect despite reducing their infectiveness. Finally, single amino acid mutations G196A and R198H nearly abolished the binding of gp85 to Tva and nullified the infectiveness of these viruses to DF-1. This study paves the way for exploring the molecular mechanisms of the binding of Tva to ALV-K SU.
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Affiliation(s)
- Jian Chen
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Jinqun Li
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Lizhen Li
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Peng Liu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Yong Xiang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Weisheng Cao
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China.,Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China.,Key Laboratory of Veterinary Vaccine Innovation of the Ministry of Agriculture, Guangzhou, China.,National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, Guangzhou, China
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Ozorowski G, Torres JL, Santos-Martins D, Forli S, Ward AB. A Strain-Specific Inhibitor of Receptor-Bound HIV-1 Targets a Pocket near the Fusion Peptide. Cell Rep 2020; 33:108428. [PMID: 33238117 PMCID: PMC7701285 DOI: 10.1016/j.celrep.2020.108428] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 10/07/2020] [Accepted: 11/03/2020] [Indexed: 01/18/2023] Open
Abstract
Disruption of viral fusion represents a viable, albeit under-explored, target for HIV therapeutics. Here, while studying the receptor-bound envelope glycoprotein conformation by cryoelectron microscopy (cryo-EM), we identify a pocket near the base of the trimer containing a bound detergent molecule and perform in silico drug screening by using a library of drug-like and commercially available molecules. After down-selection, we solve cryo-EM structures that validate the binding of two small molecule hits in very similar manners to the predicted binding poses, including interactions with aromatic residues within the fusion peptide. One of the molecules demonstrates low micromolar inhibition of the autologous virus by using a very rare phenylalanine in the fusion peptide and stabilizing the surrounding region. This work demonstrates that small molecules can target the fusion process, providing an additional target for anti-HIV therapeutics, and highlights the need to explore how fusion peptide sequence variations affect receptor-mediated conformational states across diverse HIV strains.
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Affiliation(s)
- Gabriel Ozorowski
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA; Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, International AIDS Vaccine Initiative Neutralizing Antibody Center, and Collaboration for AIDS Vaccine Discovery, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Jonathan L Torres
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA; Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, International AIDS Vaccine Initiative Neutralizing Antibody Center, and Collaboration for AIDS Vaccine Discovery, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Diogo Santos-Martins
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Stefano Forli
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
| | - Andrew B Ward
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA; Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, International AIDS Vaccine Initiative Neutralizing Antibody Center, and Collaboration for AIDS Vaccine Discovery, The Scripps Research Institute, La Jolla, CA 92037, USA.
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39
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Jurado S, Moog C, Cano-Muñoz M, Schmidt S, Laumond G, Ruocco V, Standoli S, Polo-Megías D, Conejero-Lara F, Morel B. Probing Vulnerability of the gp41 C-Terminal Heptad Repeat as Target for Miniprotein HIV Inhibitors. J Mol Biol 2020; 432:5577-5592. [PMID: 32822695 DOI: 10.1016/j.jmb.2020.08.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 08/09/2020] [Accepted: 08/10/2020] [Indexed: 12/20/2022]
Abstract
One of the therapeutic strategies in HIV neutralization is blocking membrane fusion. In this process, tight interaction between the N-terminal and C-terminal heptad-repeat (NHR and CHR) regions of gp41 is essential to promote membranes apposition and merging. We have previously developed single-chain proteins (named covNHR) that accurately mimic the complete gp41 NHR region in its trimeric conformation. They tightly bind CHR-derived peptides and show a potent and broad HIV inhibitory activity in vitro. However, the extremely high binding affinity (sub-picomolar) is not in consonance with their inhibitory activity (nanomolar), likely due to partial or temporal accessibility of their target in the virus. Here, we have designed and characterized two single-chain covNHR miniproteins each encompassing one of the two halves of the NHR region and containing two of the four sub-pockets of the NHR crevice. The two miniproteins fold as trimeric helical bundles as expected but while the C-terminal covNHR (covNHR-C) miniprotein is highly stable, the N-terminal counterpart (covNHR-N) shows only marginal stability that could be improved by engineering an internal disulfide bond. Both miniproteins bind their respective complementary CHR peptides with moderate (micromolar) affinity. Moreover, the covNHR-N miniproteins can access their target in the context of trimeric native envelope proteins and show significant inhibitory activity for several HIV pseudoviruses. In contrast, covNHR-C cannot bind its target sequence and neither inhibits HIV, indicating a higher vulnerability of C-terminal part of CHR. These results may guide the development of novel HIV inhibitors targeting the gp41 CHR region.
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Affiliation(s)
- Samuel Jurado
- Departamento de Química Física, Instituto de Biotecnología e Unidad de Excelencia de Química Aplicada a Biomedicina y Medioambiente (UEQ), Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain
| | - Christiane Moog
- INSERM U1109, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - Mario Cano-Muñoz
- Departamento de Química Física, Instituto de Biotecnología e Unidad de Excelencia de Química Aplicada a Biomedicina y Medioambiente (UEQ), Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain
| | - Sylvie Schmidt
- INSERM U1109, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - Géraldine Laumond
- INSERM U1109, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - Valentina Ruocco
- Departamento de Química Física, Instituto de Biotecnología e Unidad de Excelencia de Química Aplicada a Biomedicina y Medioambiente (UEQ), Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain
| | - Sara Standoli
- Departamento de Química Física, Instituto de Biotecnología e Unidad de Excelencia de Química Aplicada a Biomedicina y Medioambiente (UEQ), Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain
| | - Daniel Polo-Megías
- Departamento de Química Física, Instituto de Biotecnología e Unidad de Excelencia de Química Aplicada a Biomedicina y Medioambiente (UEQ), Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain
| | - Francisco Conejero-Lara
- Departamento de Química Física, Instituto de Biotecnología e Unidad de Excelencia de Química Aplicada a Biomedicina y Medioambiente (UEQ), Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain.
| | - Bertrand Morel
- Departamento de Química Física, Instituto de Biotecnología e Unidad de Excelencia de Química Aplicada a Biomedicina y Medioambiente (UEQ), Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain.
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Beitari S, Pan Q, Finzi A, Liang C. Differential Pressures of SERINC5 and IFITM3 on HIV-1 Envelope Glycoprotein over the Course of HIV-1 Infection. J Virol 2020; 94:e00514-20. [PMID: 32493821 DOI: 10.1128/JVI.00514-20] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Accepted: 05/25/2020] [Indexed: 12/23/2022] Open
Abstract
Infection of human immunodeficiency virus type 1 (HIV-1) is subject to restriction by cellular factors. Serine incorporator 5 (SERINC5) and interferon-inducible transmembrane 3 (IFITM3) proteins represent two of these restriction factors, which inhibit HIV-1 entry into target cells. Both proteins impede fusion of the viral membrane with the cellular membrane and the formation of a viral fusion pore, and both are countered by the HIV-1 envelope glycoprotein (Env). Given the immense and lasting pressure which Env endures from host adaptive immune responses, it is important to understand whether and how HIV-1 Env is able to maintain the resistance to SERINC5 and IFITM3 throughout the course of infection. We have thus examined a panel of HIV-1 Env clones that were isolated at different stages of viral infection-transmission, acute, and chronic. While HIV-1 Env clones from the transmission stage are resistant to both SERINC5 and IFITM3, as infection progresses into the acute and chronic stages, the resistance to IFITM3 but not to SERINC5 is gradually lost. We further discovered a significant correlation between the resistance of HIV-1 Env to soluble CD4 inhibition and the resistance to SERINC5 but not to IFITM3. Interestingly, the miniprotein CD4 mimetic M48U1 sensitizes HIV-1 Env to the inhibition by SERINC5 but not IFITM3. Together, these data indicate that SERINC5 and IFITM3 exert differential inhibitory pressures on HIV-1 Env over different stages of HIV-1 infection and that HIV-1 Env uses varied strategies to resist these two restriction factors.IMPORTANCE HIV-1 Env protein is exposed to the inhibition not only by humoral response, but also by host restriction factors, including serine incorporator 5 (SERINC5) and interferon-inducible transmembrane 3 (IFITM3). This study investigates how HIV-1 envelope glycoprotein (Env) manages to overcome the pressures from all these different host inhibition mechanisms over the long course of viral infection. HIV-1 Env preserves the resistance to SERINC5 but becomes sensitive to IFITM3 when infection progresses into the chronic stage. Our study also supports the possibility of using CD4 mimetic compounds to sensitize HIV-1 Env to the inhibition by SERINC5 as a potential therapeutic strategy.
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Cui X, Cao Z, Wang S, Adler SP, McVoy MA, Snapper CM. Immunization with Human Cytomegalovirus Core Fusion Machinery and Accessory Envelope Proteins Elicit Strong Synergistic Neutralizing Activities. Vaccines (Basel) 2020; 8:vaccines8020179. [PMID: 32294946 PMCID: PMC7348949 DOI: 10.3390/vaccines8020179] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 04/04/2020] [Accepted: 04/10/2020] [Indexed: 12/15/2022] Open
Abstract
Human cytomegalovirus (HCMV) core fusion machinery proteins gB and gH/gL, and accessory proteins UL128/UL130/UL131A, are the key envelope proteins that mediate HCMV entry into and infection of host cells. To determine whether these HCMV envelope proteins could elicit neutralizing activities synergistically, we immunized rabbits with individual or various combinations of these proteins adsorbed to aluminum hydroxide mixed with CpG-ODN. We then analyzed serum neutralizing activities with multiple HCMV laboratory strains and clinical isolates. HCMV trimeric gB and gH/gL elicited high and moderate titers of HCMV neutralizing activity, respectively. HCMV gB in combination with gH/gL elicited up to 17-fold higher HCMV neutralizing activities compared to the sum of neutralizing activity elicited by the individual proteins analyzed with both fibroblasts and epithelial cells. HCMV gB+gH/gL+UL128/UL130/UL131A in combination increased the neutralizing activity up to 32-fold compared to the sum of neutralizing activities elicited by the individual proteins analyzed with epithelial cells. Adding UL128/UL130/UL131A to gB and gH/gL combination did not increase further the HCMV neutralizing activity analyzed with fibroblasts. These data suggest that the combination of HCMV core fusion machinery envelope proteins gB+gH/gL or the combination of gB and pentameric complex could be ideal vaccine candidates that would induce optimal immune responses against HCMV infection.
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Affiliation(s)
- Xinle Cui
- The Institute for Vaccine Research and Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
- Correspondence: ; Tel.: +1-301-295-3498
| | - Zhouhong Cao
- The Institute for Vaccine Research and Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Shuishu Wang
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | | | - Michael A. McVoy
- Department of Pediatrics, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Clifford M. Snapper
- The Institute for Vaccine Research and Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
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42
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Klasse PJ, Ozorowski G, Sanders RW, Moore JP. Env Exceptionalism: Why Are HIV-1 Env Glycoproteins Atypical Immunogens? Cell Host Microbe 2020; 27:507-518. [PMID: 32272076 PMCID: PMC7187920 DOI: 10.1016/j.chom.2020.03.018] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 03/17/2020] [Accepted: 03/22/2020] [Indexed: 11/24/2022]
Abstract
Recombinant HIV-1 envelope (Env) glycoproteins of ever-increasing sophistication have been evaluated as vaccine candidates for over 30 years. Structurally defined mimics of native trimeric Env glycoproteins (e.g., SOSIP trimers) present multiple epitopes for broadly neutralizing antibodies (bNAbs) and their germline precursors, but elicitation of bNAbs remains elusive. Here, we argue that the interactions between Env and the immune system render it exceptional among viral vaccine antigens and hinder its immunogenicity in absolute and comparative terms. In other words, Env binds to CD4 on key immune cells and transduces signals that can compromise their function. Moreover, the extensive array of oligomannose glycans on Env shields peptidic B cell epitopes, impedes the presentation of T helper cell epitopes, and attracts mannose binding proteins, which could affect the antibody response. We suggest lines of research for assessing how to overcome obstacles that the exceptional features of Env impose on the creation of a successful HIV-1 vaccine.
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Affiliation(s)
- P J Klasse
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, New York, NY 10065, USA
| | - Gabriel Ozorowski
- Department of Integrative Structural and Computational Biology, Consortium for HIV Vaccine Development, Scripps Research Institute, La Jolla, CA 92037, USA
| | - Rogier W Sanders
- Department of Medical Microbiology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - John P Moore
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, New York, NY 10065, USA.
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43
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Anasir MI, Ramanathan B, Poh CL. Structure-Based Design of Antivirals against Envelope Glycoprotein of Dengue Virus. Viruses 2020; 12:v12040367. [PMID: 32225021 PMCID: PMC7232406 DOI: 10.3390/v12040367] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 02/24/2020] [Accepted: 02/25/2020] [Indexed: 02/06/2023] Open
Abstract
Dengue virus (DENV) presents a significant threat to global public health with more than 500,000 hospitalizations and 25,000 deaths annually. Currently, there is no clinically approved antiviral drug to treat DENV infection. The envelope (E) glycoprotein of DENV is a promising target for drug discovery as the E protein is important for viral attachment and fusion. Understanding the structure and function of DENV E protein has led to the exploration of structure-based drug discovery of antiviral compounds and peptides against DENV infections. This review summarizes the structural information of the DENV E protein with regards to DENV attachment and fusion. The information enables the development of antiviral agents through structure-based approaches. In addition, this review compares the potency of antivirals targeting the E protein with the antivirals targeting DENV multifunctional enzymes, repurposed drugs and clinically approved antiviral drugs. None of the current DENV antiviral candidates possess potency similar to the approved antiviral drugs which indicates that more efforts and resources must be invested before an effective DENV drug materializes.
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Affiliation(s)
- Mohd Ishtiaq Anasir
- Center for Virus and Vaccine Research, School of Science and Technology, Sunway University, Kuala Lumpur, Selangor 47500, Malaysia;
| | - Babu Ramanathan
- Department of Biological Sciences, School of Science and Technology, Sunway University, Kuala Lumpur, Selangor 47500, Malaysia;
| | - Chit Laa Poh
- Center for Virus and Vaccine Research, School of Science and Technology, Sunway University, Kuala Lumpur, Selangor 47500, Malaysia;
- Correspondence: ; Tel.: +60-3-7491-8622; Fax: +60-3-5635-8633
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Durham ND, Howard AR, Govindan R, Senjobe F, Fels JM, Diehl WE, Luban J, Chandran K, Munro JB. Real-Time Analysis of Individual Ebola Virus Glycoproteins Reveals Pre-Fusion, Entry-Relevant Conformational Dynamics. Viruses 2020; 12:v12010103. [PMID: 31952255 PMCID: PMC7019799 DOI: 10.3390/v12010103] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/09/2020] [Accepted: 01/10/2020] [Indexed: 12/21/2022] Open
Abstract
The Ebola virus (EBOV) envelope glycoprotein (GP) mediates the fusion of the virion membrane with the membrane of susceptible target cells during infection. While proteolytic cleavage of GP by endosomal cathepsins and binding of the cellular receptor Niemann-Pick C1 protein (NPC1) are essential steps for virus entry, the detailed mechanisms by which these events promote membrane fusion remain unknown. Here, we applied single-molecule Förster resonance energy transfer (smFRET) imaging to investigate the structural dynamics of the EBOV GP trimeric ectodomain, and the functional transmembrane protein on the surface of pseudovirions. We show that in both contexts, pre-fusion GP is dynamic and samples multiple conformations. Removal of the glycan cap and NPC1 binding shift the conformational equilibrium, suggesting stabilization of conformations relevant to viral fusion. Furthermore, several neutralizing antibodies enrich alternative conformational states. This suggests that these antibodies neutralize EBOV by restricting access to GP conformations relevant to fusion. This work demonstrates previously unobserved dynamics of pre-fusion EBOV GP and presents a platform with heightened sensitivity to conformational changes for the study of GP function and antibody-mediated neutralization.
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Affiliation(s)
- Natasha D. Durham
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01605, USA;
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine and Sackler School of Graduate Biomedical Sciences, Boston, MA 02111, USA; (A.R.H.); (F.S.)
- Correspondence: (N.D.D.); (J.B.M.)
| | - Angela R. Howard
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine and Sackler School of Graduate Biomedical Sciences, Boston, MA 02111, USA; (A.R.H.); (F.S.)
| | - Ramesh Govindan
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01605, USA;
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine and Sackler School of Graduate Biomedical Sciences, Boston, MA 02111, USA; (A.R.H.); (F.S.)
| | - Fernando Senjobe
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine and Sackler School of Graduate Biomedical Sciences, Boston, MA 02111, USA; (A.R.H.); (F.S.)
| | - J. Maximilian Fels
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; (J.M.F.); (K.C.)
| | - William E. Diehl
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA; (W.E.D.); (J.L.)
| | - Jeremy Luban
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA; (W.E.D.); (J.L.)
| | - Kartik Chandran
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; (J.M.F.); (K.C.)
| | - James B. Munro
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01605, USA;
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine and Sackler School of Graduate Biomedical Sciences, Boston, MA 02111, USA; (A.R.H.); (F.S.)
- Correspondence: (N.D.D.); (J.B.M.)
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Shao J, Huang Q, Liu X, Di D, Dileepan M, Brisse M, Ly H, Liang Y. Biological Characterization of Conserved Residues within the Cytoplasmic Tail of the Pichinde Arenaviral Glycoprotein Subunit 2 (GP2). J Virol 2019; 93:e01277-19. [PMID: 31462569 DOI: 10.1128/JVI.01277-19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 08/20/2019] [Indexed: 12/13/2022] Open
Abstract
Several mammarenaviruses can cause deadly hemorrhagic fever infections in humans, with limited preventative and therapeutic measures available. Arenavirus cell entry is mediated by the viral glycoprotein (GP) complex, which consists of the stable signal peptide (SSP), the receptor-binding subunit GP1, and the transmembrane subunit GP2. The GP2 cytoplasmic tail (CT) is relatively conserved among arenaviruses and is known to interact with the SSP to regulate GP processing and membrane fusion, but its biological role in the context of an infectious virus has not been fully characterized. Using a Pichinde virus (PICV) GP expression vector and a PICV reverse genetics system, we systematically characterized the functional roles of 12 conserved residues within the GP2 CT in GP processing, trafficking, assembly, and fusion, as well as in viral replication. Except for P478A and K505A R508A, alanine substitutions at conserved residues abolished GP processing and membrane fusion in plasmid-transfected cells. Six invariant H and C residues and W503 are essential for viral replication, as evidenced by the fact that their mutant viruses could not be rescued. Both P480A and R482A mutant viruses were rescued, grew similarly to wild-type (WT) virus, and produced evidently processed GP1 and GP2 subunits in virus-infected cells, despite the fact that the same mutations abolished GP processing and membrane fusion in a plasmid-based protein expression system, illustrating the importance of using an infectious-virus system for analyzing viral glycoprotein function. In summary, our results demonstrate an essential biological role of the GP2 CT in arenavirus replication and suggest it as a potential novel target for developing antivirals and/or attenuated viral vaccine candidates.IMPORTANCE Several arenaviruses, such as Lassa virus (LASV), can cause severe and lethal hemorrhagic fever diseases with high mortality and morbidity, for which no FDA-approved vaccines or therapeutics are available. Viral entry is mediated by the arenavirus GP complex, which consists of the stable signal peptide (SSP), the receptor-binding subunit GP1, and the transmembrane subunit GP2. The cytoplasmic tail (CT) of GP2 is highly conserved among arenaviruses, but its functional role in viral replication is not completely understood. Using a reverse genetics system of a prototypic arenavirus, Pichinde virus (PICV), we show that the GP2 CT contains certain conserved residues that are essential for virus replication, implicating it as a potentially good target for developing antivirals and live-attenuated viral vaccines against deadly arenavirus pathogens.
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Abstract
HIV-1 envelope glycoprotein [Env; trimeric (gp160)3 cleaved to (gp120/gp41)3] attaches the virion to a susceptible cell and induces fusion of viral and cell membranes to initiate infection. It interacts with the primary receptor CD4 and coreceptor (e.g., chemokine receptor CCR5 or CXCR4) to allow viral entry by triggering large structural rearrangements and unleashing the fusogenic potential of gp41 to induce membrane fusion. Recent advances in structural biology of HIV-1 Env and its complexes with the cellular receptors have revealed molecular details of HIV-1 entry and yielded new mechanistic insights. In this review, I summarize our latest understanding of the HIV-1 membrane fusion process and discuss possible pathways for productive viral entry.
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Affiliation(s)
- Bing Chen
- Division of Molecular Medicine, Boston Children's Hospital, and Department of Pediatrics, Harvard Medical School, 3 Blackfan Street, Boston, MA 02115, USA.
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Jurado S, Cano-Muñoz M, Morel B, Standoli S, Santarossa E, Moog C, Schmidt S, Laumond G, Cámara-Artigas A, Conejero-Lara F. Structural and Thermodynamic Analysis of HIV-1 Fusion Inhibition Using Small gp41 Mimetic Proteins. J Mol Biol 2019; 431:3091-3106. [PMID: 31255705 DOI: 10.1016/j.jmb.2019.06.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 06/21/2019] [Accepted: 06/21/2019] [Indexed: 11/25/2022]
Abstract
Development of effective inhibitors of the fusion between HIV-1 and the host cell membrane mediated by gp41 continues to be a grand challenge due to an incomplete understanding of the molecular and mechanistic details of the fusion process. We previously developed single-chain, chimeric proteins (named covNHR) that accurately mimic the N-heptad repeat (NHR) region of gp41 in a highly stable coiled-coil conformation. These molecules bind strongly to peptides derived from the gp41 C-heptad repeat (CHR) and are potent and broad HIV-1 inhibitors. Here, we investigated two covNHR variants differing in two mutations, V10E and Q123R (equivalent to V38E and Q40R in gp41 sequence) that reproduce the effect of HIV-1 mutations associated with resistance to fusion inhibitors, such as T20 (enfuvirtide). A detailed calorimetric analysis of the binding between the covNHR proteins and CHR peptides (C34 and T20) reveals drastic changes in affinity due to the mutations as a result of local changes in interactions at the site of T20 resistance. The crystallographic structure of the covNHR:C34 complex shows a virtually identical CHR-NHR binding interface to that of the post-fusion structure of gp41 and underlines an important role of buried interfacial water molecules in binding affinity and in development of resistance against CHR peptides. Despite the great difference in affinity, both covNHR variants demonstrate strong inhibitory activity for a wide variety of HIV-1 strains. These properties support the high potential of these covNHR proteins as new potent HIV-1 inhibitors. Our results may guide future inhibition approaches.
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Affiliation(s)
- Samuel Jurado
- Departamento de Química Física e Instituto de Biotecnología, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain
| | - Mario Cano-Muñoz
- Departamento de Química Física e Instituto de Biotecnología, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain
| | - Bertrand Morel
- Departamento de Química Física e Instituto de Biotecnología, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain
| | - Sara Standoli
- Departamento de Química Física e Instituto de Biotecnología, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain
| | - Elisabetta Santarossa
- Departamento de Química Física e Instituto de Biotecnología, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain
| | - Christiane Moog
- INSERM U1109, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - Sylvie Schmidt
- INSERM U1109, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - Géraline Laumond
- INSERM U1109, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - Ana Cámara-Artigas
- Department of Chemistry and Physics, Agrifood Campus of International Excellence (ceiA3) and CIAMBITAL, University of Almería, Carretera de Sacramento, 04120 Almeria, Spain
| | - Francisco Conejero-Lara
- Departamento de Química Física e Instituto de Biotecnología, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain.
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Liu XQ, Xin HY, Lyu YN, Ma ZW, Peng XC, Xiang Y, Wang YY, Wu ZJ, Cheng JT, Ji JF, Zhong JX, Ren BX, Wang XW, Xin HW. Oncolytic herpes simplex virus tumor targeting and neutralization escape by engineering viral envelope glycoproteins. Drug Deliv 2019; 25:1950-1962. [PMID: 30799657 PMCID: PMC6282442 DOI: 10.1080/10717544.2018.1534895] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Oncolytic herpes simplex viruses (oHSVs) have been approved for clinical usage and become more and more popular for tumor virotherapy. However, there are still many issues for the oHSVs used in clinics and clinical trials. The main issues are the limited anti-tumor effects, intratumor injection, and some side effects. To overcome such challenges, here we review the genetic engineering of the envelope glycoproteins for oHSVs to target tumors specifically, and at the same time we summarize the many neutralization antibodies against the envelope glycoproteins and align the neutralization epitopes with functional domains of the respective glycoproteins for future identification of new functions of the glycoproteins and future engineering of the epitopes to escape from host neutralization.
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Affiliation(s)
- Xiao-Qin Liu
- a Faculty of Medicine, The Second School of Clinical Medicine , Yangtze University, Nanhuan , Jingzhou , Hubei , China.,b Laboratory of Oncology, Faculty of Medicine, Center for Molecular Medicine, School of Basic Medicine , Yangtze University , Jingzhou , Hubei , China.,c Faculty of Medicine, Department of Biochemistry and Molecular Biology, School of Basic Medicine , Yangtze University , Jingzhou , Hubei , China.,d Department of Nursing and Medical Imaging Technology , Yangtze University , Jingzhou , Hubei , China
| | - Hong-Yi Xin
- e Star Array Pte Ltd , JTC Medtech Hub , Singapore , Singapore
| | - Yan-Ning Lyu
- f Institute for Infectious Diseases and Endemic Diseases Prevention and Control, Beijing Center for Diseases Prevention and Control , Beijing , China
| | - Zhao-Wu Ma
- a Faculty of Medicine, The Second School of Clinical Medicine , Yangtze University, Nanhuan , Jingzhou , Hubei , China.,b Laboratory of Oncology, Faculty of Medicine, Center for Molecular Medicine, School of Basic Medicine , Yangtze University , Jingzhou , Hubei , China.,c Faculty of Medicine, Department of Biochemistry and Molecular Biology, School of Basic Medicine , Yangtze University , Jingzhou , Hubei , China
| | - Xiao-Chun Peng
- a Faculty of Medicine, The Second School of Clinical Medicine , Yangtze University, Nanhuan , Jingzhou , Hubei , China.,b Laboratory of Oncology, Faculty of Medicine, Center for Molecular Medicine, School of Basic Medicine , Yangtze University , Jingzhou , Hubei , China.,g Faculty of Medicine, Department of Pathophysiology, School of Basic Medicine , Yangtze University , Jingzhou , Hubei , China
| | - Ying Xiang
- a Faculty of Medicine, The Second School of Clinical Medicine , Yangtze University, Nanhuan , Jingzhou , Hubei , China.,b Laboratory of Oncology, Faculty of Medicine, Center for Molecular Medicine, School of Basic Medicine , Yangtze University , Jingzhou , Hubei , China.,c Faculty of Medicine, Department of Biochemistry and Molecular Biology, School of Basic Medicine , Yangtze University , Jingzhou , Hubei , China
| | - Ying-Ying Wang
- a Faculty of Medicine, The Second School of Clinical Medicine , Yangtze University, Nanhuan , Jingzhou , Hubei , China.,b Laboratory of Oncology, Faculty of Medicine, Center for Molecular Medicine, School of Basic Medicine , Yangtze University , Jingzhou , Hubei , China.,c Faculty of Medicine, Department of Biochemistry and Molecular Biology, School of Basic Medicine , Yangtze University , Jingzhou , Hubei , China
| | - Zi-Jun Wu
- a Faculty of Medicine, The Second School of Clinical Medicine , Yangtze University, Nanhuan , Jingzhou , Hubei , China.,b Laboratory of Oncology, Faculty of Medicine, Center for Molecular Medicine, School of Basic Medicine , Yangtze University , Jingzhou , Hubei , China.,c Faculty of Medicine, Department of Biochemistry and Molecular Biology, School of Basic Medicine , Yangtze University , Jingzhou , Hubei , China.,d Department of Nursing and Medical Imaging Technology , Yangtze University , Jingzhou , Hubei , China
| | - Jun-Ting Cheng
- a Faculty of Medicine, The Second School of Clinical Medicine , Yangtze University, Nanhuan , Jingzhou , Hubei , China.,b Laboratory of Oncology, Faculty of Medicine, Center for Molecular Medicine, School of Basic Medicine , Yangtze University , Jingzhou , Hubei , China.,c Faculty of Medicine, Department of Biochemistry and Molecular Biology, School of Basic Medicine , Yangtze University , Jingzhou , Hubei , China
| | - Jia-Fu Ji
- h Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Gastrointestinal Surgery , Peking University Cancer Hospital and Institute , Haidian , Beijing , China
| | - Ji-Xin Zhong
- i Cardiovascular Research Institute , Case Western Reserve University , Cleveland , OH , USA
| | - Bo-Xu Ren
- a Faculty of Medicine, The Second School of Clinical Medicine , Yangtze University, Nanhuan , Jingzhou , Hubei , China.,d Department of Nursing and Medical Imaging Technology , Yangtze University , Jingzhou , Hubei , China
| | - Xian-Wang Wang
- a Faculty of Medicine, The Second School of Clinical Medicine , Yangtze University, Nanhuan , Jingzhou , Hubei , China.,b Laboratory of Oncology, Faculty of Medicine, Center for Molecular Medicine, School of Basic Medicine , Yangtze University , Jingzhou , Hubei , China.,j Faculty of Medicine, Department of Laboratory Medicine, School of Basic Medicine , Yangtze University , Jingzhou , Hubei , China
| | - Hong-Wu Xin
- a Faculty of Medicine, The Second School of Clinical Medicine , Yangtze University, Nanhuan , Jingzhou , Hubei , China.,b Laboratory of Oncology, Faculty of Medicine, Center for Molecular Medicine, School of Basic Medicine , Yangtze University , Jingzhou , Hubei , China.,c Faculty of Medicine, Department of Biochemistry and Molecular Biology, School of Basic Medicine , Yangtze University , Jingzhou , Hubei , China
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Lu W, Chen S, Yu J, Behrens R, Wiggins J, Sherer N, Liu SL, Xiong Y, Xiang SH, Wu L. The Polar Region of the HIV-1 Envelope Protein Determines Viral Fusion and Infectivity by Stabilizing the gp120-gp41 Association. J Virol 2019; 93:e02128-18. [PMID: 30651369 DOI: 10.1128/JVI.02128-18] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 01/12/2019] [Indexed: 02/06/2023] Open
Abstract
HIV-1 enters cells through binding between viral envelope glycoprotein (Env) and cellular receptors to initiate virus and cell fusion. HIV-1 Env precursor (gp160) is cleaved into two units noncovalently bound to form a trimer on virions, including a surface unit (gp120) and a transmembrane unit (gp41) responsible for virus binding and membrane fusion, respectively. The polar region (PR) at the N terminus of gp41 comprises 17 residues, including 7 polar amino acids. Previous studies suggested that the PR contributes to HIV-1 membrane fusion and infectivity; however, the precise role of the PR in Env-mediated viral entry and the underlying mechanisms remain unknown. Here, we show that the PR is critical for HIV-1 fusion and infectivity by stabilizing Env trimers. Through analyzing the PR sequences of 57,645 HIV-1 isolates, we performed targeted mutagenesis and functional studies of three highly conserved polar residues in the PR (S532P, T534A, and T536A) which have not been characterized previously. We found that single or combined mutations of these three residues abolished or significantly decreased HIV-1 infectivity without affecting viral production. These PR mutations abolished or significantly reduced HIV-1 fusion with target cells and also Env-mediated cell-cell fusion. Three PR mutations containing S532P substantially reduced gp120 and gp41 association, Env trimer stability, and increased gp120 shedding. Furthermore, S532A mutation significantly reduced HIV-1 infectivity and fusogenicity but not Env expression and cleavage. Our findings suggest that the PR of gp41, particularly the key residue S532, is structurally essential for maintaining HIV-1 Env trimer, viral fusogenicity, and infectivity.IMPORTANCE Although extensive studies of the transmembrane unit (gp41) of HIV-1 Env have led to a fusion inhibitor clinically used to block viral entry, the functions of different domains of gp41 in HIV-1 fusion and infectivity are not fully elucidated. The polar region (PR) of gp41 has been proposed to participate in HIV-1 membrane fusion in biochemical analyses, but its role in viral entry and infectivity remain unclear. In our effort to characterize three nucleotide mutations of an HIV-1 RNA element that partially overlaps the PR coding sequence, we identified a novel function of the PR that determines viral fusion and infectivity. We further demonstrated the structural and functional impact of six PR mutations on HIV-1 Env stability, viral fusion, and infectivity. Our findings reveal the previously unappreciated function of the PR and the underlying mechanisms, highlighting the important role of the PR in regulating HIV-1 fusion and infectivity.
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Mabvakure BM, Scheepers C, Garrett N, Abdool Karim S, Williamson C, Morris L, Moore PL. Positive Selection at Key Residues in the HIV Envelope Distinguishes Broad and Strain-Specific Plasma Neutralizing Antibodies. J Virol 2019; 93:e01685-18. [PMID: 30567996 DOI: 10.1128/JVI.01685-18] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 11/28/2018] [Indexed: 01/07/2023] Open
Abstract
Millions of people are still being infected with HIV decades after the first recognition of the virus. Currently, no vaccine is able to elicit bNAbs that will prevent infection by global HIV strains. Several studies have implicated HIV Env diversity in the development of breadth. However, Env evolution in individuals who fail to develop breadth despite mounting potent strain-specific neutralizing responses has not been well defined. Using longitudinal neutralization, epitope mapping, and sequence data from 14 participants, we found that overall measures of viral diversity were similar in all donors. However, the number of positively selected sites within Env epitopes was higher in bNAb participants than in strain-specific donors. We further identified common sites that were positively selected as bNAbs developed. These data indicate that while viral diversity is required for breadth, this should be highly targeted to specific residues to shape the elicitation of bNAbs by vaccination. The development of HIV broadly neutralizing antibodies (bNAbs) has previously been shown to be associated with viral evolution and high levels of genetic diversity in the HIV envelope (Env) glycoprotein. However, few studies have examined Env evolution in those who fail to develop neutralization breadth in order to assess whether bNAbs result from distinct evolutionary pathways. We compared Env evolution in eight HIV-1-infected participants who developed bNAbs to six donors with similar viral loads who did not develop bNAbs over three years of infection. We focused on Env V1V2 and C3V4, as these are major targets for both strain-specific neutralizing antibodies (nAbs) and bNAbs. Overall evolutionary rates (ranging from 9.92 × 10−3 to 4.1 × 10−2 substitutions/site/year) and viral diversity (from 1.1% to 6.5%) across Env, and within targeted epitopes, did not distinguish bNAb donors from non-bNAb donors. However, bNAb participants had more positively selected residues within epitopes than those without bNAbs, and several of these were common among bNAb donors. A comparison of the kinetics of strain-specific nAbs and bNAbs indicated that selection pressure at these residues increased with the onset of breadth. These data suggest that highly targeted viral evolution rather than overall envelope diversity is associated with neutralization breadth. The association of shared positively selected sites with the onset of breadth highlights the importance of diversity at specific positions in these epitopes for bNAb development, with implications for the development of sequential and cocktail immunization strategies. IMPORTANCE Millions of people are still being infected with HIV decades after the first recognition of the virus. Currently, no vaccine is able to elicit bNAbs that will prevent infection by global HIV strains. Several studies have implicated HIV Env diversity in the development of breadth. However, Env evolution in individuals who fail to develop breadth despite mounting potent strain-specific neutralizing responses has not been well defined. Using longitudinal neutralization, epitope mapping, and sequence data from 14 participants, we found that overall measures of viral diversity were similar in all donors. However, the number of positively selected sites within Env epitopes was higher in bNAb participants than in strain-specific donors. We further identified common sites that were positively selected as bNAbs developed. These data indicate that while viral diversity is required for breadth, this should be highly targeted to specific residues to shape the elicitation of bNAbs by vaccination.
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