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Schaerlaekens S, Jacobs L, Stobbelaar K, Cos P, Delputte P. All Eyes on the Prefusion-Stabilized F Construct, but Are We Missing the Potential of Alternative Targets for Respiratory Syncytial Virus Vaccine Design? Vaccines (Basel) 2024; 12:97. [PMID: 38250910 PMCID: PMC10819635 DOI: 10.3390/vaccines12010097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 01/12/2024] [Accepted: 01/13/2024] [Indexed: 01/23/2024] Open
Abstract
Respiratory Syncytial Virus (RSV) poses a significant global health concern as a major cause of lower respiratory tract infections (LRTIs). Over the last few years, substantial efforts have been directed towards developing vaccines and therapeutics to combat RSV, leading to a diverse landscape of vaccine candidates. Notably, two vaccines targeting the elderly and the first maternal vaccine have recently been approved. The majority of the vaccines and vaccine candidates rely solely on a prefusion-stabilized conformation known for its highly neutralizing epitopes. Although, so far, this antigen design appears to be successful for the elderly, our current understanding remains incomplete, requiring further improvement and refinement in this field. Pediatric vaccines still have a long journey ahead, and we must ensure that vaccines currently entering the market do not lose efficacy due to the emergence of mutations in RSV's circulating strains. This review will provide an overview of the current status of vaccine designs and what to focus on in the future. Further research into antigen design is essential, including the exploration of the potential of alternative RSV proteins to address these challenges and pave the way for the development of novel and effective vaccines, especially in the pediatric population.
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Affiliation(s)
- Sofie Schaerlaekens
- Laboratory for Microbiology, Parasitology and Hygiene, University of Antwerp (UA), Universiteitsplein 1 S.7, 2610 Antwerp, Belgium; (S.S.); (L.J.); (K.S.); (P.C.)
| | - Lotte Jacobs
- Laboratory for Microbiology, Parasitology and Hygiene, University of Antwerp (UA), Universiteitsplein 1 S.7, 2610 Antwerp, Belgium; (S.S.); (L.J.); (K.S.); (P.C.)
| | - Kim Stobbelaar
- Laboratory for Microbiology, Parasitology and Hygiene, University of Antwerp (UA), Universiteitsplein 1 S.7, 2610 Antwerp, Belgium; (S.S.); (L.J.); (K.S.); (P.C.)
- Pediatrics Department, Antwerp University Hospital (UZA), Wilrijkstraat 10, 2650 Edegem, Belgium
| | - Paul Cos
- Laboratory for Microbiology, Parasitology and Hygiene, University of Antwerp (UA), Universiteitsplein 1 S.7, 2610 Antwerp, Belgium; (S.S.); (L.J.); (K.S.); (P.C.)
- Infla-Med Centre of Excellence, University of Antwerp (UA), Universiteitsplein 1 S.7, 2610 Antwerp, Belgium
| | - Peter Delputte
- Laboratory for Microbiology, Parasitology and Hygiene, University of Antwerp (UA), Universiteitsplein 1 S.7, 2610 Antwerp, Belgium; (S.S.); (L.J.); (K.S.); (P.C.)
- Infla-Med Centre of Excellence, University of Antwerp (UA), Universiteitsplein 1 S.7, 2610 Antwerp, Belgium
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2
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Liu DJ, Liu CC, Zhong XQ, Wu X, Zhang HH, Lu SW, Shen ZL, Song WW, Zhao SL, Peng YS, Zheng HP, Wan MY, Chen YQ, Deng L. Boost immunizations with NA-derived peptide conjugates achieve induction of NA inhibition antibodies and heterologous influenza protections. Cell Rep 2023; 42:112766. [PMID: 37421618 DOI: 10.1016/j.celrep.2023.112766] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 05/12/2023] [Accepted: 06/22/2023] [Indexed: 07/10/2023] Open
Abstract
Neuraminidase is suggested as an important component for developing a universal influenza vaccine. Targeted induction of neuraminidase-specific broadly protective antibodies by vaccinations is challenging. To overcome this, we rationally select the highly conserved peptides from the consensus amino acid sequence of the globular head domains of neuraminidase. Inspired by the B cell receptor evolution process, a reliable sequential immunization regimen is designed to result in immuno-focusing by steering bulk immune responses to a selected region where broadly protective B lymphocyte epitopes reside. After priming neuraminidase protein-specific antibody responses in C57BL/6 or BALB/c inbred mice strains by immunization or pre-infection, boost immunizations with certain neuraminidase-derived peptide-keyhole limpet hemocyanin conjugates significantly strengthened serum neuraminidase inhibition activities and cross-protections. Overall, this study provides proof of concept for a peptide-based sequential immunization strategy for achieving targeted induction of cross-protective antibody response, which provides references for designing universal vaccines against other highly variable pathogens.
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Affiliation(s)
- De-Jian Liu
- Hunan Provincial Key Laboratory of Medical Virology, College of Biology, Hunan University, Changsha 410082, China
| | - Cui-Cui Liu
- Hunan Provincial Key Laboratory of Medical Virology, College of Biology, Hunan University, Changsha 410082, China
| | - Xiu-Qin Zhong
- Hunan Provincial Key Laboratory of Medical Virology, College of Biology, Hunan University, Changsha 410082, China
| | - Xuan Wu
- Hunan Provincial Key Laboratory of Medical Virology, College of Biology, Hunan University, Changsha 410082, China
| | - Hui-Hui Zhang
- Bioinformatics Center, College of Biology, Hunan University, Changsha 410082, China
| | - Shang-Wen Lu
- Bioinformatics Center, College of Biology, Hunan University, Changsha 410082, China
| | - Zhuo-Ling Shen
- Hunan Provincial Key Laboratory of Medical Virology, College of Biology, Hunan University, Changsha 410082, China
| | - Wen-Wen Song
- Hunan Provincial Key Laboratory of Medical Virology, College of Biology, Hunan University, Changsha 410082, China
| | - Shi-Long Zhao
- Hunan Provincial Key Laboratory of Medical Virology, College of Biology, Hunan University, Changsha 410082, China
| | - You-Song Peng
- Hunan Provincial Key Laboratory of Medical Virology, College of Biology, Hunan University, Changsha 410082, China; Bioinformatics Center, College of Biology, Hunan University, Changsha 410082, China
| | - He-Ping Zheng
- Hunan Provincial Key Laboratory of Medical Virology, College of Biology, Hunan University, Changsha 410082, China; Bioinformatics Center, College of Biology, Hunan University, Changsha 410082, China
| | - Mu-Yang Wan
- Hunan Provincial Key Laboratory of Medical Virology, College of Biology, Hunan University, Changsha 410082, China
| | - Yao-Qing Chen
- School of Public Health (Shenzhen), Sun Yat-Sen University, Shenzhen, Guangdong Province 518107, China
| | - Lei Deng
- Hunan Provincial Key Laboratory of Medical Virology, College of Biology, Hunan University, Changsha 410082, China; Bioinformatics Center, College of Biology, Hunan University, Changsha 410082, China; Beijing Weimiao Biotechnology Co., Ltd., Haidian District, Beijing 100000, China.
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3
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Hervé PL, Dhelft V, Zuniga A, Ghasparian A, Rassek O, Yim KC, Donne N, Lambert PH, Benhamou PH, Sampson HA, Mondoulet L. Epicutaneous immunization using synthetic virus-like particles efficiently boosts protective immunity to respiratory syncytial virus. Vaccine 2021; 39:4555-4563. [PMID: 34154864 DOI: 10.1016/j.vaccine.2021.03.081] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 03/22/2021] [Accepted: 03/24/2021] [Indexed: 02/02/2023]
Abstract
Despite the substantial health and economic burden caused by RSV-associated illness, no vaccine is available. The sole licensed treatment (palivizumab), composed of a monoclonal neutralizing antibody, blocks the fusion of the virus to the host cell but does not prevent infection. The development of a safe and efficacious RSV vaccine is therefore a priority, but also a considerable challenge, and new innovative strategies are warranted. Most of the adult population encounter regular RSV infections and can elicit a robust neutralizing antibody response, but unfortunately it wanes over time and reinfections during subsequent seasons are common. One approach to protect the mother and young infant from RSV infection is to administer a vaccine capable of boosting preexisting RSV immunity during pregnancy, which would provide protection to the fetus through passive transfer of maternal antibodies, thus preventing primary RSV infection in newborns during their first months of life. Here, we describe the preclinical evaluation of an epicutaneous RSV vaccine booster that combines epicutaneous patches as a delivery platform and a Synthetic Virus-Like Particles (SVLP)-based vaccine displaying multiple RSV F-protein site II (FsII, palivizumab epitope) mimetic as antigen (V-306). We demonstrated in mice that epicutaneous immunization with V-306 efficiently boosts preexisting immunity induced by the homologous V-306 administered subcutaneously. This boosting was characterized by a significant increase in F- and FsII-specific antibodies capable of competing with palivizumab for its target antigen and neutralize RSV. More importantly, epicutaneous booster immunization with V-306 significantly decreased lung viral replication in experimental mice after intranasal RSV challenge, without inducing enhanced RSV disease. In conclusion, an epicutaneous booster vaccine based on V-306 is safe and efficacious in enhancing RSV preexisting immunity in mice. This needle-free vaccine candidate would be potentially suited as a booster vaccine for vulnerable populations such as young infants via pregnant women, and the elderly.
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Affiliation(s)
- Pierre-Louis Hervé
- DBV Technologies, 177-181 Avenue Pierre Brossolette, 92120 Montrouge, France.
| | - Véronique Dhelft
- DBV Technologies, 177-181 Avenue Pierre Brossolette, 92120 Montrouge, France
| | - Armando Zuniga
- Virometix AG, Wagisstrasse 14, CH-8952 Schlieren, Switzerland
| | - Arin Ghasparian
- Virometix AG, Wagisstrasse 14, CH-8952 Schlieren, Switzerland
| | - Oliver Rassek
- Virometix AG, Wagisstrasse 14, CH-8952 Schlieren, Switzerland
| | - Kevin C Yim
- Sigmovir Biosystems, Inc., 9610 Medical Center Drive, Suite #100, Rockville, MD 20850, USA
| | - Nathalie Donne
- DBV Technologies, 177-181 Avenue Pierre Brossolette, 92120 Montrouge, France
| | - Paul-Henri Lambert
- WHO Collaborative Center for Vaccine Immunology, Department of Pathology-Immunology, University of Geneva, Geneva, Switzerland
| | | | - Hugh A Sampson
- DBV Technologies, 12 East 49th Street Tower 49, Suite 4001, New York, NY 10017, USA
| | - Lucie Mondoulet
- DBV Technologies, 177-181 Avenue Pierre Brossolette, 92120 Montrouge, France
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4
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Borochova K, Niespodziana K, Focke-Tejkl M, Hofer G, Keller W, Valenta R. Dissociation of the respiratory syncytial virus F protein-specific human IgG, IgA and IgM response. Sci Rep 2021; 11:3551. [PMID: 33574352 PMCID: PMC7878790 DOI: 10.1038/s41598-021-82893-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 11/20/2020] [Indexed: 01/30/2023] Open
Abstract
Human respiratory syncytial virus (RSV) is one of the most important causes of severe respiratory tract infections in early childhood. The only prophylactic protection is the neutralizing antibody, palivizumab, which targets a conformational epitope of the RSV fusion (F) protein. The F protein is generated as a F0 precursor containing two furin cleavage sites allowing excision of the P27 fragment and then gives rise to a fusion-competent version consisting of the N-terminal F2 subunit and the a C-terminal F1 subunits linked by two disulphide bonds. To investigate natural human F-specific antibody responses, F2 conferring the species-specificity of RSV, was expressed in Escherichia coli. Furthermore, the F0 protein, comprising both subunits F2 and F1, was expressed as palivizumab-reactive glycoprotein in baculovirus-infected insect cells. Six overlapping F2-derived peptides lacking secondary structure were synthesized. The analysis of IgG, IgA and IgM responses of adult subjects to native versions and denatured forms of F2 and F0 and to unfolded F2-derived peptides revealed that mainly non-conformational F epitopes, some of which represented cryptic epitopes which are not exposed on the proteins were recognized. Furthermore, we found a dissociation of IgG, IgA and IgM antibody responses to F epitopes with F2 being a major target for the F-specific IgM response. The scattered and dissociated immune response to F may explain why the natural RSV-specific antibody response is only partially protective underlining the need for vaccines focusing human antibody responses towards neutralizing RSV epitopes.
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Affiliation(s)
- Kristina Borochova
- grid.22937.3d0000 0000 9259 8492Department of Pathophysiology and Allergy Research, Division of Immunopathology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Katarzyna Niespodziana
- grid.22937.3d0000 0000 9259 8492Department of Pathophysiology and Allergy Research, Division of Immunopathology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Margarete Focke-Tejkl
- grid.22937.3d0000 0000 9259 8492Department of Pathophysiology and Allergy Research, Division of Immunopathology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Gerhard Hofer
- grid.5110.50000000121539003Institute of Molecular Biosciences, BioTechMed Graz, University of Graz, Graz, Austria
| | - Walter Keller
- grid.5110.50000000121539003Institute of Molecular Biosciences, BioTechMed Graz, University of Graz, Graz, Austria
| | - Rudolf Valenta
- grid.22937.3d0000 0000 9259 8492Department of Pathophysiology and Allergy Research, Division of Immunopathology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria ,grid.465277.5NRC Institute of Immunology FMBA of Russia, Moscow, Russia ,grid.448878.f0000 0001 2288 8774Laboratory for Immunopathology, Department of Clinical Immunology and Allergy, Sechenov First Moscow State Medical University, Moscow, Russia ,grid.459693.4Karl Landsteiner University of Health Sciences, Krems, Austria
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5
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Abstract
Enabled by new approaches for rapid identification and selection of human monoclonal antibodies, atomic-level structural information for viral surface proteins, and capacity for precision engineering of protein immunogens and self-assembling nanoparticles, a new era of antigen design and display options has evolved. While HIV-1 vaccine development has been a driving force behind these technologies and concepts, clinical proof-of-concept for structure-based vaccine design may first be achieved for respiratory syncytial virus (RSV), where conformation-dependent access to neutralization-sensitive epitopes on the fusion glycoprotein determines the capacity to induce potent neutralizing activity. Success with RSV has motivated structure-based stabilization of other class I viral fusion proteins for use as immunogens and demonstrated the importance of structural information for developing vaccines against other viral pathogens, particularly difficult targets that have resisted prior vaccine development efforts. Solving viral surface protein structures also supports rapid vaccine antigen design and application of platform manufacturing approaches for emerging pathogens.
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Affiliation(s)
- Barney S Graham
- Vaccine Research Center, National Institute of Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20850, USA;
| | - Morgan S A Gilman
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712, USA;
| | - Jason S McLellan
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712, USA;
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6
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Gilman MSA, Furmanova-Hollenstein P, Pascual G, B van 't Wout A, Langedijk JPM, McLellan JS. Transient opening of trimeric prefusion RSV F proteins. Nat Commun 2019; 10:2105. [PMID: 31068578 PMCID: PMC6506550 DOI: 10.1038/s41467-019-09807-5] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 04/02/2019] [Indexed: 01/19/2023] Open
Abstract
The respiratory syncytial virus (RSV) F glycoprotein is a class I fusion protein that mediates viral entry and is a major target of neutralizing antibodies. Structures of prefusion forms of RSV F, as well as other class I fusion proteins, have revealed compact trimeric arrangements, yet whether these trimeric forms can transiently open remains unknown. Here, we perform structural and biochemical studies on a recently isolated antibody, CR9501, and demonstrate that it enhances the opening of prefusion-stabilized RSV F trimers. The 3.3 Å crystal structure of monomeric RSV F bound to CR9501, combined with analysis of over 25 previously determined RSV F structures, reveals a breathing motion of the prefusion conformation. We also demonstrate that full-length RSV F trimers transiently open and dissociate on the cell surface. Collectively, these findings have implications for the function of class I fusion proteins, as well as antibody prophylaxis and vaccine development for RSV.
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MESH Headings
- Animals
- Antibodies, Neutralizing/chemistry
- Antibodies, Neutralizing/immunology
- Antibodies, Neutralizing/metabolism
- Antibodies, Viral/chemistry
- Antibodies, Viral/immunology
- Antibodies, Viral/metabolism
- B-Lymphocytes/virology
- Chlorocebus aethiops
- Computer Simulation
- Crystallography, X-Ray
- Drug Development
- HEK293 Cells
- HeLa Cells
- Humans
- Models, Molecular
- Protein Multimerization/physiology
- Respiratory Syncytial Virus Infections/immunology
- Respiratory Syncytial Virus Infections/prevention & control
- Respiratory Syncytial Virus Infections/virology
- Respiratory Syncytial Virus Vaccines/immunology
- Respiratory Syncytial Virus, Human/isolation & purification
- Respiratory Syncytial Virus, Human/physiology
- Vero Cells
- Viral Fusion Proteins/chemistry
- Viral Fusion Proteins/immunology
- Viral Fusion Proteins/metabolism
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Affiliation(s)
- Morgan S A Gilman
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, 03755, USA
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA
| | | | - Gabriel Pascual
- Janssen Immunosciences, World Without Disease Accelerator, San Diego, CA, 92121, USA
| | - Angélique B van 't Wout
- Janssen Prevention Center, Janssen Vaccines & Prevention B.V, Leiden, CN, 2333, The Netherlands
- AlphaBiomics, London, SW4 0PA, United Kingdom
| | | | - Jason S McLellan
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA.
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7
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Song J, Wang H, Ng TI, Cui A, Zhu S, Huang Y, Sun L, Yang Z, Yu D, Yu P, Zhang H, Zhang Y, Xu W. Sequence Analysis of the Fusion Protein Gene of Human Respiratory Syncytial Virus Circulating in China from 2003 to 2014. Sci Rep 2018; 8:17618. [PMID: 30514963 PMCID: PMC6279739 DOI: 10.1038/s41598-018-35894-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 11/09/2018] [Indexed: 11/09/2022] Open
Abstract
The human respiratory syncytial virus (HRSV) fusion (F) protein is important for HRSV infection, but few studies have examined the genetic diversity of the F gene from Chinese samples. In this study, a total of 330 HRSV F sequences collected from different regions of China between 2003 and 2014 were analyzed to understand their genetic characteristics. In addition, these sequences were compared with 1150 HRSV F sequences in Genbank from 18 other countries. In phylogenetic analysis, Chinese HRSV F sequences sorted into a number of clusters containing sequences from China as well as other countries. F sequences from different genotypes (as determined based on the G gene sequences) within a HRSV subgroup could be found in the same clusters in phylogenetic trees generated based on F gene sequences. Amino acid analysis showed that HRSV F sequences from China and other countries were highly conserved. Of interest, F protein sequences from all Chinese samples were completely conserved at the palivizumab binding site, thus predicting the susceptibility of these strains to this neutralizing antibody. In conclusion, HRSV F sequences from China between 2003 and 2014, similar to those from other countries, were highly conserved.
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Affiliation(s)
- Jinhua Song
- WHO WPRO Regional Reference Measles/Rubella Laboratory and Key Laboratory of Medical Virology, National Health Commission of the People's Republic of China, National Institute for Viral Disease Control and Prevention, China Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Huiling Wang
- WHO WPRO Regional Reference Measles/Rubella Laboratory and Key Laboratory of Medical Virology, National Health Commission of the People's Republic of China, National Institute for Viral Disease Control and Prevention, China Center for Disease Control and Prevention, Beijing, People's Republic of China
| | | | - Aili Cui
- WHO WPRO Regional Reference Measles/Rubella Laboratory and Key Laboratory of Medical Virology, National Health Commission of the People's Republic of China, National Institute for Viral Disease Control and Prevention, China Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Shuangli Zhu
- WHO WPRO Regional Reference Measles/Rubella Laboratory and Key Laboratory of Medical Virology, National Health Commission of the People's Republic of China, National Institute for Viral Disease Control and Prevention, China Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Yanzhi Huang
- Jilin Children's Medical Center, Children's Hospital of Changchun, Changchun, People's Republic of China
| | - Liwei Sun
- Jilin Children's Medical Center, Children's Hospital of Changchun, Changchun, People's Republic of China
| | - Zifeng Yang
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, People's Republic of China
| | - Deshan Yu
- Gansu Provincial Centers for Disease Control and Prevention, Lanzhou, People's Republic of China
| | - Pengbo Yu
- Shaanxi Provincial Centers for Disease Control and Prevention, Xian, People's Republic of China
| | - Hong Zhang
- Hunan Provincial Centers for Disease Control and Prevention, Changsha, People's Republic of China
| | - Yan Zhang
- WHO WPRO Regional Reference Measles/Rubella Laboratory and Key Laboratory of Medical Virology, National Health Commission of the People's Republic of China, National Institute for Viral Disease Control and Prevention, China Center for Disease Control and Prevention, Beijing, People's Republic of China.
| | - Wenbo Xu
- WHO WPRO Regional Reference Measles/Rubella Laboratory and Key Laboratory of Medical Virology, National Health Commission of the People's Republic of China, National Institute for Viral Disease Control and Prevention, China Center for Disease Control and Prevention, Beijing, People's Republic of China.
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8
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Clinical Potential of Prefusion RSV F-specific Antibodies. Trends Microbiol 2017; 26:209-219. [PMID: 29054341 DOI: 10.1016/j.tim.2017.09.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 08/30/2017] [Accepted: 09/25/2017] [Indexed: 11/23/2022]
Abstract
Human respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in the very young. The RSV fusion protein (F) is essential for virus entry because it mediates viral and host membrane fusion. During this fusion process F is converted from a metastable prefusion conformation into an energetically favored postfusion state. Antibodies that target F can prevent viral entry and reduce disease caused by RSV. During recent years, many prefusion F-specific antibodies have been described. These antibodies typically have stronger RSV-neutralizing activity compared to those that also bind F in the postfusion conformation. Here, we describe how F-specific antibodies protect against RSV and why specifically targeting prefusion F could have great clinical potential.
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9
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Jaberolansar N, Chappell KJ, Watterson D, Bermingham IM, Toth I, Young PR, Skwarczynski M. Induction of high titred, non-neutralising antibodies by self-adjuvanting peptide epitopes derived from the respiratory syncytial virus fusion protein. Sci Rep 2017; 7:11130. [PMID: 28894111 PMCID: PMC5593926 DOI: 10.1038/s41598-017-10415-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 08/08/2017] [Indexed: 11/09/2022] Open
Abstract
Respiratory syncytial virus (RSV) causes severe lower respiratory tract illness in infants and young children. The significant morbidity and mortality rates associated with RSV infection make an effective RSV vaccine development a priority. Two neutralising antibody binding sites, Ø and II, located on the pre-fusion RSV F glycoprotein are prime candidates for epitope-focused vaccine design. We report on a vaccine strategy that utilises a lipid core peptide (LCP) delivery system with self-adjuvanting properties in conjunction with either the antigenic site Ø or II (B cell epitopes) along with PADRE as a T helper cell epitope. These LCP constructs adopted the desired helical conformation in solution and were recognised by their cognate antibodies D25 and Motavizumab, specific for site Ø and II on RSV F protein, respectively. The LCP constructs were capable of eliciting higher levels of antigen specific antibodies than those induced by antigens administered with complete Freund's adjuvant, demonstrating the potent adjuvanting properties of LCP delivery. However, the antibodies induced failed to recognise native F protein or neutralise virus infectivity. These results provide a note of caution in assuming that peptide vaccines, successfully designed to structurally mimic minimal linear B cell epitopes, will necessarily elicit the desired immune response.
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Affiliation(s)
- Noushin Jaberolansar
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Keith J Chappell
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia.
- Australian Infectious Diseases Research Centre, The University of Queensland, St Lucia, Queensland, Australia.
| | - Daniel Watterson
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia.
- Australian Infectious Diseases Research Centre, The University of Queensland, St Lucia, Queensland, Australia.
| | - Imogen M Bermingham
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Istvan Toth
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, St Lucia, Queensland, Australia
- School of Pharmacy, The University of Queensland, Woolloongabba, Queensland, Australia
| | - Paul R Young
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, St Lucia, Queensland, Australia
| | - Mariusz Skwarczynski
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia.
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10
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Hervé PL, Deloizy C, Descamps D, Rameix-Welti MA, Fix J, McLellan JS, Eléouët JF, Riffault S. RSV N-nanorings fused to palivizumab-targeted neutralizing epitope as a nanoparticle RSV vaccine. NANOMEDICINE : NANOTECHNOLOGY, BIOLOGY, AND MEDICINE 2017; 13:411-420. [PMID: 27553073 PMCID: PMC5698904 DOI: 10.1016/j.nano.2016.08.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 07/21/2016] [Accepted: 08/03/2016] [Indexed: 01/01/2023]
Abstract
Respiratory syncytial virus (RSV) is the leading cause of acute respiratory infections in children, yet no vaccine is available. The sole licensed preventive treatment against RSV is composed of a monoclonal neutralizing antibody (palivizumab), which targets a conformational epitope located on the fusion protein (F). Palivizumab reduces the burden of bronchiolitis but does not prevent infection. Thus, the development of RSV vaccines remains a priority. We previously evaluated nanorings formed by RSV nucleoprotein (N) as an RSV vaccine, as well as an immunostimulatory carrier for heterologous antigens. Here, we linked the palivizumab-targeted epitope (called FsII) to N, to generate N-FsII-nanorings. Intranasal N-FsII immunization elicited anti-F antibodies in mice that were non-neutralizing in vitro. Nevertheless, RSV-challenged animals were better protected against virus replication than mice immunized with N-nanorings, especially in the upper airways. In conclusion, an N-FsII-focused vaccine is an attractive candidate combining N-specific cellular immunity and F-specific antibodies for protection.
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Affiliation(s)
| | | | | | - Marie-Anne Rameix-Welti
- INSERM U1173, UFR Simone Veil, UVSQ, Saint-Quentin en Yvelines, France; AP-HP, Ambroise Paré Hospital, Microbiology Laboratory, Boulogne-Billancourt, France
| | - Jenna Fix
- VIM, INRA, Université Paris-Saclay, Jouy-en-Josas, France
| | - Jason S McLellan
- Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
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11
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Melero JA. Influence of antigen conformation and mode of presentation on the antibody and protective responses against human respiratory syncytial virus: relevance for vaccine development. Expert Rev Vaccines 2016; 15:1319-25. [DOI: 10.1080/14760584.2016.1175941] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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12
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GS-5806 Inhibits a Broad Range of Respiratory Syncytial Virus Clinical Isolates by Blocking the Virus-Cell Fusion Process. Antimicrob Agents Chemother 2015; 60:1264-73. [PMID: 26666922 DOI: 10.1128/aac.01497-15] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 11/05/2015] [Indexed: 12/22/2022] Open
Abstract
Respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infections in infants and young children. In addition, RSV causes significant morbidity and mortality in hospitalized elderly and immunocompromised patients. Currently, only palivizumab, a monoclonal antibody against the RSV fusion (F) protein, and inhaled ribavirin are approved for the prophylactic and therapeutic treatment of RSV, respectively. Therefore, there is a clinical need for safe and effective therapeutic agents for RSV infections. GS-5806, discovered via chemical optimization of a hit from a high-throughput antiviral-screening campaign, selectively inhibits a diverse set of 75 RSV subtype A and B clinical isolates (mean 50% effective concentration [EC50] = 0.43 nM). The compound maintained potency in primary human airway epithelial cells and exhibited low cytotoxicity in human cell lines and primary cell cultures (selectivity > 23,000-fold). Time-of-addition and temperature shift studies demonstrated that GS-5806 does not block RSV attachment to cells but interferes with virus entry. Follow-up experiments showed potent inhibition of RSV F-mediated cell-to-cell fusion. RSV A and B variants resistant to GS-5806, due to mutations in F protein (RSV A, L138F or F140L/N517I, and RSV B, F488L or F488S), were isolated and showed cross-resistance to other RSV fusion inhibitors, such as VP-14637, but remained fully sensitive to palivizumab and ribavirin. In summary, GS-5806 is a potent and selective RSV fusion inhibitor with antiviral activity against a diverse set of RSV clinical isolates. The compound is currently under clinical investigation for the treatment of RSV infection in pediatric, immunocompromised, and elderly patients.
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13
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Luo X, Liu T, Wang Y, Jia H, Zhang Y, Caballero D, Du J, Wang RE, Wang D, Schultz PG, Wang F. An Epitope-Specific Respiratory Syncytial Virus Vaccine Based on an Antibody Scaffold. Angew Chem Int Ed Engl 2015; 54:14531-4. [PMID: 26434555 PMCID: PMC4715490 DOI: 10.1002/anie.201507928] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Indexed: 11/08/2022]
Abstract
Respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infections in children. We have generated an epitope-specific RSV vaccine by grafting a neutralizing epitope (F-epitope) in its native conformation into an immunoglobulin scaffold. The resulting antibody fusion exhibited strong binding affinity to Motavizumab, an RSV neutralizing antibody, and effectively induced potent neutralizing antibodies in mice. This work illustrates the potential of the immunoglobulin molecule as a scaffold to present conformationally constrained B-cell epitopes.
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Affiliation(s)
- Xiaozhou Luo
- Department of Chemistry, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037 (USA)
| | - Tao Liu
- California Institute for Biomedical Research (Calibr), 11119 N. Torrey Pines Road, La Jolla, CA 92037 (USA)
| | - Ying Wang
- California Institute for Biomedical Research (Calibr), 11119 N. Torrey Pines Road, La Jolla, CA 92037 (USA)
| | - Haiqun Jia
- California Institute for Biomedical Research (Calibr), 11119 N. Torrey Pines Road, La Jolla, CA 92037 (USA)
| | - Yuhan Zhang
- California Institute for Biomedical Research (Calibr), 11119 N. Torrey Pines Road, La Jolla, CA 92037 (USA)
| | - Dawna Caballero
- California Institute for Biomedical Research (Calibr), 11119 N. Torrey Pines Road, La Jolla, CA 92037 (USA)
| | - Juanjuan Du
- California Institute for Biomedical Research (Calibr), 11119 N. Torrey Pines Road, La Jolla, CA 92037 (USA)
| | - Rongsheng E Wang
- California Institute for Biomedical Research (Calibr), 11119 N. Torrey Pines Road, La Jolla, CA 92037 (USA)
| | - Danling Wang
- California Institute for Biomedical Research (Calibr), 11119 N. Torrey Pines Road, La Jolla, CA 92037 (USA)
| | - Peter G Schultz
- Department of Chemistry, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037 (USA).
| | - Feng Wang
- California Institute for Biomedical Research (Calibr), 11119 N. Torrey Pines Road, La Jolla, CA 92037 (USA).
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14
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Structural and Computational Biology in the Design of Immunogenic Vaccine Antigens. J Immunol Res 2015; 2015:156241. [PMID: 26526043 PMCID: PMC4615220 DOI: 10.1155/2015/156241] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 08/02/2015] [Indexed: 01/08/2023] Open
Abstract
Vaccination is historically one of the most important medical interventions for the prevention of infectious disease. Previously, vaccines were typically made of rather crude mixtures of inactivated or attenuated causative agents. However, over the last 10–20 years, several important technological and computational advances have enabled major progress in the discovery and design of potently immunogenic recombinant protein vaccine antigens. Here we discuss three key breakthrough approaches that have potentiated structural and computational vaccine design. Firstly, genomic sciences gave birth to the field of reverse vaccinology, which has enabled the rapid computational identification of potential vaccine antigens. Secondly, major advances in structural biology, experimental epitope mapping, and computational epitope prediction have yielded molecular insights into the immunogenic determinants defining protective antigens, enabling their rational optimization. Thirdly, and most recently, computational approaches have been used to convert this wealth of structural and immunological information into the design of improved vaccine antigens. This review aims to illustrate the growing power of combining sequencing, structural and computational approaches, and we discuss how this may drive the design of novel immunogens suitable for future vaccines urgently needed to increase the global prevention of infectious disease.
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15
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Luo X, Liu T, Wang Y, Jia H, Zhang Y, Caballero D, Du J, Wang RE, Wang D, Schultz PG, Wang F. An Epitope-Specific Respiratory Syncytial Virus Vaccine Based on an Antibody Scaffold. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201507928] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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16
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Loomis RJ, Johnson PR. Emerging Vaccine Technologies. Vaccines (Basel) 2015; 3:429-47. [PMID: 26343196 PMCID: PMC4494353 DOI: 10.3390/vaccines3020429] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Revised: 05/05/2015] [Accepted: 05/18/2015] [Indexed: 12/13/2022] Open
Abstract
Vaccination has proven to be an invaluable means of preventing infectious diseases by reducing both incidence of disease and mortality. However, vaccines have not been effectively developed for many diseases including HIV-1, hepatitis C virus (HCV), tuberculosis and malaria, among others. The emergence of new technologies with a growing understanding of host-pathogen interactions and immunity may lead to efficacious vaccines against pathogens, previously thought impossible.
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Affiliation(s)
- Rebecca J Loomis
- The Children's Hospital of Philadelphia Research Institute, Philadelphia, PA 19104, USA.
| | - Philip R Johnson
- The Children's Hospital of Philadelphia Research Institute, Philadelphia, PA 19104, USA.
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17
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Schickli JH, Whitacre DC, Tang RS, Kaur J, Lawlor H, Peters CJ, Jones JE, Peterson DL, McCarthy MP, Van Nest G, Milich DR. Palivizumab epitope-displaying virus-like particles protect rodents from RSV challenge. J Clin Invest 2015; 125:1637-47. [PMID: 25751145 PMCID: PMC4409022 DOI: 10.1172/jci78450] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 01/22/2015] [Indexed: 12/12/2022] Open
Abstract
Respiratory syncytial virus (RSV) is the most common cause of serious viral bronchiolitis in infants, young children, and the elderly. Currently, there is not an FDA-approved vaccine available for RSV, though the mAb palivizumab is licensed to reduce the incidence of RSV disease in premature or at-risk infants. The palivizumab epitope is a well-characterized, approximately 24-aa helix-loop-helix structure on the RSV fusion (F) protein (F254-277). Here, we genetically inserted this epitope and multiple site variants of this epitope within a versatile woodchuck hepadnavirus core-based virus-like particle (WHcAg-VLP) to generate hybrid VLPs that each bears 240 copies of the RSV epitope in a highly immunogenic arrayed format. A challenge of such an epitope-focused approach is that to be effective, the conformational F254-277 epitope must elicit antibodies that recognize the intact virus. A number of hybrid VLPs containing RSV F254-277 were recognized by palivizumab in vitro and elicited high-titer and protective neutralizing antibody in rodents. Together, the results from this proof-of-principle study suggest that the WHcAg-VLP technology may be an applicable approach to eliciting a response to other structural epitopes.
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Affiliation(s)
| | | | | | | | | | | | | | - Darrell L. Peterson
- Virginia Commonwealth University, Department of Biochemistry,
Richmond, Virginia, USA
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18
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McLellan JS. Neutralizing epitopes on the respiratory syncytial virus fusion glycoprotein. Curr Opin Virol 2015; 11:70-5. [PMID: 25819327 PMCID: PMC4456247 DOI: 10.1016/j.coviro.2015.03.002] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 02/12/2015] [Accepted: 03/04/2015] [Indexed: 10/23/2022]
Abstract
Respiratory syncytial virus (RSV) is a leading cause of pneumonia and bronchiolitis, but despite decades of research a safe and effective vaccine has remained elusive. The viral fusion glycoprotein (RSV F) plays an obligatory role in the entry process and is the major target of neutralizing antibodies, making it an attractive target for vaccine development. This review will summarize the recently determined structures of RSV F in the prefusion and postfusion conformations and describe the location and properties of neutralizing epitopes on RSV F, including the newly identified prefusion-specific epitopes. The influence of these findings on vaccine development will also be discussed, with a focus on the rational design and optimization of vaccine antigens.
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Affiliation(s)
- Jason S McLellan
- Department of Biochemistry, Geisel School of Medicine at Dartmouth, 7200 Vail, Hanover, NH, 03755 USA.
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19
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Dormitzer PR, Grandi G, Rappuoli R. Structural vaccinology starts to deliver. Nat Rev Microbiol 2013; 10:807-13. [PMID: 23154260 DOI: 10.1038/nrmicro2893] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Following the impact of the genomics revolution on vaccine research and the development of reverse vaccinology, it was predicted that another new approach, structure-based antigen design, would become a driving force for vaccine innovation. Now, 5 years on, there are several examples of how structure-based design, or structural vaccinology, can deliver new vaccine antigens that were not possible before. Here, we discuss some of these examples and the contribution of structural vaccinology to our understanding of the protective epitopes of important bacterial and viral pathogens.
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Affiliation(s)
- Philip R Dormitzer
- Novartis Vaccines and Diagnostics Inc., 350 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
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20
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Selection and characterization of human respiratory syncytial virus escape mutants resistant to a polyclonal antiserum raised against the F protein. Arch Virol 2012; 157:1071-80. [PMID: 22411099 DOI: 10.1007/s00705-012-1274-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Accepted: 02/02/2012] [Indexed: 10/28/2022]
Abstract
A human respiratory syncytial virus (HRSV) neutralization escape mutant was obtained after 56 serial passages in the presence of a polyclonal antiserum raised against the F protein. Nucleotide sequence analysis of this escape mutant virus revealed two amino acid substitutions: Asn268Ile and Val533Met. When this virus was allowed to grow in the absence of the anti-F polyclonal serum, only the mutation Asn268Ile was stably maintained. Both the double and single escape mutant viruses lost reactivity with mAbs belonging to antigenic site II of the fusion protein of RSV. Mutation Asn268Ile has already been reported in RS viruses that are resistant to mAbs 47F and 11 and palivizumab (PZ). We have thus identified a novel mutation (Val533Met) in the transmembrane domain of the F protein that was selected under immune pressure.
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21
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McLellan JS, Correia BE, Chen M, Yang Y, Graham BS, Schief WR, Kwong PD. Design and characterization of epitope-scaffold immunogens that present the motavizumab epitope from respiratory syncytial virus. J Mol Biol 2011; 409:853-66. [PMID: 21549714 PMCID: PMC3107930 DOI: 10.1016/j.jmb.2011.04.044] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Revised: 04/15/2011] [Accepted: 04/15/2011] [Indexed: 10/18/2022]
Abstract
Respiratory syncytial virus (RSV) is a major cause of respiratory tract infections in infants, but an effective vaccine has not yet been developed. An ideal vaccine would elicit protective antibodies while avoiding virus-specific T-cell responses, which have been implicated in vaccine-enhanced disease with previous RSV vaccines. We propose that heterologous proteins designed to present RSV-neutralizing antibody epitopes and to elicit cognate antibodies have the potential to fulfill these vaccine requirements, as they can be fashioned to be free of viral T-cell epitopes. Here we present the design and characterization of three epitope-scaffolds that present the epitope of motavizumab, a potent neutralizing antibody that binds to a helix-loop-helix motif in the RSV fusion glycoprotein. Two of the epitope-scaffolds could be purified, and one epitope-scaffold based on a Staphylococcus aureus protein A domain bound motavizumab with kinetic and thermodynamic properties consistent with the free epitope-scaffold being stabilized in a conformation that closely resembled the motavizumab-bound state. This epitope-scaffold was well folded as assessed by circular dichroism and isothermal titration calorimetry, and its crystal structure (determined in complex with motavizumab to 1.9 Å resolution) was similar to the computationally designed model, with all hydrogen-bond interactions critical for binding to motavizumab preserved. Immunization of mice with this epitope-scaffold failed to elicit neutralizing antibodies but did elicit sera with F binding activity. The elicitation of F binding antibodies suggests that some of the design criteria for eliciting protective antibodies without virus-specific T-cell responses are being met, but additional optimization of these novel immunogens is required.
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Affiliation(s)
- Jason S McLellan
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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22
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Gaunt ER, Jansen RR, Poovorawan Y, Templeton KE, Toms GL, Simmonds P. Molecular epidemiology and evolution of human respiratory syncytial virus and human metapneumovirus. PLoS One 2011; 6:e17427. [PMID: 21390255 PMCID: PMC3046979 DOI: 10.1371/journal.pone.0017427] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2010] [Accepted: 02/02/2011] [Indexed: 11/23/2022] Open
Abstract
Human respiratory syncytial virus (HRSV) and human metapneumovirus (HMPV) are ubiquitous respiratory pathogens of the Pneumovirinae subfamily of the Paramyxoviridae. Two major surface antigens are expressed by both viruses; the highly conserved fusion (F) protein, and the extremely diverse attachment (G) glycoprotein. Both viruses comprise two genetic groups, A and B. Circulation frequencies of the two genetic groups fluctuate for both viruses, giving rise to frequently observed switching of the predominantly circulating group. Nucleotide sequence data for the F and G gene regions of HRSV and HMPV variants from the UK, the Netherlands, Bangkok and data available from Genbank were used to identify clades of both viruses. Several contemporary circulating clades of HRSV and HMPV were identified by phylogenetic reconstructions. The molecular epidemiology and evolutionary dynamics of clades were modelled in parallel. Times of origin were determined and positively selected sites were identified. Sustained circulation of contemporary clades of both viruses for decades and their global dissemination demonstrated that switching of the predominant genetic group did not arise through the emergence of novel lineages each respiratory season, but through the fluctuating circulation frequencies of pre-existing lineages which undergo proliferative and eclipse phases. An abundance of sites were identified as positively selected within the G protein but not the F protein of both viruses. For HRSV, these were discordant with previously identified residues under selection, suggesting the virus can evade immune responses by generating diversity at multiple sites within linear epitopes. For both viruses, different sites were identified as positively selected between genetic groups.
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Affiliation(s)
- Eleanor R Gaunt
- Centre for Infectious Diseases, University of Edinburgh, Edinburgh, United Kingdom.
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23
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McLellan JS, Chen M, Chang JS, Yang Y, Kim A, Graham BS, Kwong PD. Structure of a major antigenic site on the respiratory syncytial virus fusion glycoprotein in complex with neutralizing antibody 101F. J Virol 2010; 84:12236-44. [PMID: 20881049 PMCID: PMC2976384 DOI: 10.1128/jvi.01579-10] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Accepted: 09/20/2010] [Indexed: 11/20/2022] Open
Abstract
Respiratory syncytial virus (RSV) is a major cause of pneumonia and bronchiolitis in infants and elderly people. Currently there is no effective vaccine against RSV, but passive prophylaxis with neutralizing antibodies reduces hospitalizations. To investigate the mechanism of antibody-mediated RSV neutralization, we undertook structure-function studies of monoclonal antibody 101F, which binds a linear epitope in the RSV fusion glycoprotein. Crystal structures of the 101F antigen-binding fragment in complex with peptides from the fusion glycoprotein defined both the extent of the linear epitope and the interactions of residues that are mutated in antibody escape variants. The structure allowed for modeling of 101F in complex with trimers of the fusion glycoprotein, and the resulting models suggested that 101F may contact additional surfaces located outside the linear epitope. This hypothesis was supported by surface plasmon resonance experiments that demonstrated 101F bound the peptide epitope ∼16,000-fold more weakly than the fusion glycoprotein. The modeling also showed no substantial clashes between 101F and the fusion glycoprotein in either the pre- or postfusion state, and cell-based assays indicated that 101F neutralization was not associated with blocking virus attachment. Collectively, these results provide a structural basis for RSV neutralization by antibodies that target a major antigenic site on the fusion glycoprotein.
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Affiliation(s)
- Jason S McLellan
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
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24
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Papenburg J, Boivin G. The distinguishing features of human metapneumovirus and respiratory syncytial virus. Rev Med Virol 2010; 20:245-60. [PMID: 20586081 DOI: 10.1002/rmv.651] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Acute respiratory tract infections (RTIs) are a leading cause of morbidity and mortality worldwide. Human Metapneumovirus (hMPV) is a member of the Metapneumovirus genus within the Pneumovirinae subfamily of the Paramyxoviridae family. Though hMPV was only discovered in 2001, a large body of work has already shown that it is the aetiologic agent of a substantial proportion of upper and lower RTIs across all age groups in both healthy and immunocompromised hosts throughout the world. RSV, also a pneumovirus, is the human pathogen most closely related to hMPV. RSV is the leading cause of pneumonia and bronchiolitis in infants and young children, but can also cause respiratory tract disease in all age groups. In this paper, we will review the salient features of the virology, epidemiology, pathogenesis, host immune responses, clinical manifestations and diagnostic modalities of hMPV, using RSV as a comparison. In addition, we will show how immunoprophylactic and therapeutic strategies studied and used in clinical practice for RSV-some with great success, and others tragic failure-have led to promising areas of research for the prevention and treatment of the significant burden of disease caused by hMPV.
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25
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Subbarayan P, Qin H, Pillai S, Lee JJ, Pfendt AP, Willing G, Miller ME, Dennis VA, Singh SR. Expression and characterization of a multivalent human respiratory syncytial virus protein. Mol Biol 2010. [DOI: 10.1134/s0026893310030106] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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26
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Anderson R, Huang Y, Langley JM. Prospects for defined epitope vaccines for respiratory syncytial virus. Future Microbiol 2010; 5:585-602. [DOI: 10.2217/fmb.10.22] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The history of vaccines for respiratory syncytial virus (RSV) illustrates the complex immunity and immunopathology to this ubiquitous virus, starting from the failed formalin-inactivated vaccine trials performed in the 1960s. An attractive alternative to traditional live or killed virus vaccines is a defined vaccine composed of discrete antigenic epitopes for which immunological activities have been characterized as comprehensively as possible. Here we present cumulative data on murine and human CD4, CD8 and neutralization epitopes identified in RSV proteins along with information regarding their associated immune responses and host-dependent variability. Identification and characterization of RSV epitopes is a rapidly expanding topic of research with potential contributions to the tailored design of improved safe and effective vaccines.
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Affiliation(s)
- Robert Anderson
- Department of Microbiology & Immunology, Pediatrics and Canadian Center for Vaccinology, Dalhousie University, Halifax, Nova Scotia, B3H 1X5, Canada
| | - Yan Huang
- Department of Microbiology & Immunology and Canadian Center for Vaccinology, Dalhousie University, Halifax, Nova Scotia, B3H 1X5, Canada
| | - Joanne M Langley
- Department of Pediatrics, Community Health & Epidemiology and Canadian Center for Vaccinology, Dalhousie University, Halifax, Nova Scotia, B3H 1X5, Canada
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27
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McLellan JS, Chen M, Kim A, Yang Y, Graham BS, Kwong PD. Structural basis of respiratory syncytial virus neutralization by motavizumab. Nat Struct Mol Biol 2010; 17:248-50. [PMID: 20098425 PMCID: PMC3050594 DOI: 10.1038/nsmb.1723] [Citation(s) in RCA: 132] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2009] [Accepted: 10/20/2009] [Indexed: 11/09/2022]
Abstract
Motavizumab is approximately tenfold more potent than its predecessor, palivizumab (Synagis), the FDA-approved monoclonal antibody used to prevent respiratory syncytial virus (RSV) infection. The structure of motavizumab in complex with a 24-residue peptide corresponding to its epitope on the RSV fusion (F) glycoprotein reveals the structural basis for this greater potency. Modeling suggests that motavizumab recognizes a different quaternary configuration of the F glycoprotein than that observed in a homologous structure.
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MESH Headings
- Antibodies, Monoclonal/chemistry
- Antibodies, Monoclonal/immunology
- Antibodies, Monoclonal, Humanized
- Antibodies, Neutralizing/chemistry
- Antibodies, Neutralizing/immunology
- Antibodies, Viral/chemistry
- Antibodies, Viral/immunology
- Antiviral Agents/chemistry
- Antiviral Agents/immunology
- Crystallography, X-Ray
- Epitopes/chemistry
- Epitopes/immunology
- Humans
- Models, Molecular
- Neutralization Tests
- Protein Structure, Quaternary
- Respiratory Syncytial Viruses/immunology
- Viral Fusion Proteins/chemistry
- Viral Fusion Proteins/immunology
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Affiliation(s)
- Jason S McLellan
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
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28
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Ulbrandt ND, Ji H, Patel NK, Barnes AS, Wilson S, Kiener PA, Suzich J, McCarthy MP. Identification of antibody neutralization epitopes on the fusion protein of human metapneumovirus. J Gen Virol 2008; 89:3113-3118. [PMID: 19008400 PMCID: PMC2885031 DOI: 10.1099/vir.0.2008/005199-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2008] [Accepted: 08/09/2008] [Indexed: 11/18/2022] Open
Abstract
Human metapneumovirus (hMPV) is genetically related to respiratory syncytial virus (RSV); both cause respiratory tract illnesses ranging from a mild cough to bronchiolitis and pneumonia. The F protein-directed monoclonal antibody (mAb) palivizumab has been shown to prevent severe lower respiratory tract RSV infection in animals and humans. We have previously reported on a panel of mAbs against the hMPV F protein that neutralize hMPV in vitro and, in two cases, in vivo. Here we describe the generation of hMPV mAb-resistant mutants (MARMs) to these neutralizing antibodies. Sequencing the F proteins of the hMPV MARMs identified several neutralizing epitopes. Interestingly, some of the epitopes mapped on the hMPV F protein coincide with homologous regions mapped previously on the RSV F protein, including the site against which the broadly protective mAb palivizumab is directed. This suggests that these homologous regions play important, conserved functions in both viruses.
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Affiliation(s)
| | - Hong Ji
- MedImmune, Inc. 1 MedImmune Way, Gaithersburg, MD 20878, USA
| | - Nita K Patel
- MedImmune, Inc. 1 MedImmune Way, Gaithersburg, MD 20878, USA
| | - Arnita S Barnes
- MedImmune, Inc. 1 MedImmune Way, Gaithersburg, MD 20878, USA
| | - Susan Wilson
- MedImmune, Inc. 1 MedImmune Way, Gaithersburg, MD 20878, USA
| | - Peter A Kiener
- MedImmune, Inc. 1 MedImmune Way, Gaithersburg, MD 20878, USA
| | - JoAnn Suzich
- MedImmune, Inc. 1 MedImmune Way, Gaithersburg, MD 20878, USA
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29
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Singh SR, Dennis VA, Carter CL, Pillai SR, Moore EG. Respiratory Syncytial Virus Recombinant F Protein (Residues 255–278) Induces a Helper T Cell Type 1 Immune Response in Mice. Viral Immunol 2007; 20:261-75. [PMID: 17603843 DOI: 10.1089/vim.2007.0008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We have developed and evaluated an immunodominant respiratory syncytial virus (RSV) F antigen in a mouse model. The antigenic region corresponding to amino acids 255-278 of the RSV F protein was cloned into a vector containing the ctxA(2)B gene of cholera toxin (CT). The recombinant protein was expressed in Escherichia coli and analyzed on sodium dodecyl sulfate-polyacrylamide gels. The purified protein was evaluated by immunoblot and ganglioside GM(1) enzyme-linked immunosorbent assay to confirm the expression of the RSV F protein and to correct association of the recombinant protein to form a holotoxin-like chimera, respectively. We hypothesized that genetic fusion of modified CT-based adjuvant with RSV F immunodominant epitopes (rRF-255) would induce protective humoral and cellular immune responses in mice. Intranasal immunization of mice with rRF-255 overall induced higher concentrations of anti-RSV F-specific antibodies in both serum and saliva as compared with mice immunized intranasally with RSV or phosphate-buffered saline (PBS). Antibody isotype analysis (IgA, IgG1, IgG2a, and IgG2b) was also performed. The predominant IgG2a antibody isotype response in combination with cytokine analysis of helper T cell type 1 (interferon-gamma, interleukin [IL]-2, IL-12 p70, and tumor necrosis factor-alpha) and helper T cell type 2 (IL-4 and IL-10) responses revealed that rRF-255 antigen induces a prominent helper T cell type 1 immune response in mice. The rRF-255 antigen also induced serum neutralizing antibodies in immunized mice. Analysis of RSV load in lungs showed that rRF-255 immunization provided significant protection compared with PBS control animals.
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Affiliation(s)
- Shree R Singh
- Department of Mathematics and Science, Alabama State University, Montgomery, Alabama 36101, USA.
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30
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Marsh R, Connor A, Gias E, Toms GL. Increased susceptibility of human respiratory syncytial virus to neutralization by anti-fusion protein antibodies on adaptation to replication in cell culture. J Med Virol 2007; 79:829-37. [PMID: 17457900 DOI: 10.1002/jmv.20892] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Subgroup A respiratory syncytial viruses present in respiratory secretions and low passage level cell culture isolates were found to be markedly less susceptible to neutralization with monoclonal antibodies (MAbs) to the F glycoprotein than the cell culture adapted A2 virus strain. Low passage virus isolates collected over a 20 year period and belonging to several sub-group A lineages were refractory to neutralization with antibodies recognizing two major neutralizing antigenic sites located sub-terminally at opposite ends of the F(1) glycoprotein sub-unit. On further passage in cell culture, virus isolates exhibited both increased infectivity titers and increased susceptibility to neutralization by antibodies to both antigenic sites. The consensus nucleotide sequence of the membrane associated proteins M and of the SH, G and F glycoprotein genes, and their intergenic regions were compared for neutralization resistant and susceptible stocks of one virus strain, R17532. No changes were observed in the known monoclonal antibody epitopes on the F glycoprotein. In line with this, the increase in susceptibility was not found to be associated with any increased binding of monoclonal antibody to isolated F glycoprotein in a BIAcore assay, thus excluding the possibility that passage in cell culture selected for viruses with mutations in the antibody binding sites. M and SH genes were conserved but a number of sites in the G and F glycoprotein genes were found to vary on adaptation to cell culture suggesting that change in susceptibility to neutralization was associated with a change in the prevalent quasispecies present in the virus population. The genetic basis of phenotypic change in susceptibility remains to be determined.
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Affiliation(s)
- R Marsh
- The School of Clinical Medical Sciences, The Medical School, The University of Newcastle upon Tyne, Newcastle upon Tyne, UK
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31
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Abstract
BACKGROUND Human respiratory syncytial virus (HRSV) is a leading cause of serious pediatric respiratory disease worldwide. Natural infection provides only partial protection as repeat infections occur throughout life. A brief review of the extent of antigenic and genetic variation observed in HRSV clinical isolates is presented. METHODS AND RESULTS Recent experimental research is reviewed, describing key factors that may explain the ability of HRSV to cause multiple infections in the same individual even in the presence of an existing immune response. It is well-appreciated that variability of the G protein, both between and within antigenic subgroups A and B, is partially responsible for repeat HRSV infections. A high level of nucleotide change resulting in amino acid change provides strong evidence for selective pressure for change in G sequences, thus new HRSV variants. Although little variation in gene-coding sequences is observed in the F protein (the second major protective antigen), new evidence of genetic variation has identified alteration of gene expression levels by selection of changes in the gene end termination signal that precedes the gene encoding the F protein. Due to obligatory sequential transcription, these changes affect downstream gene expression levels. These data suggest that modulation of F protein levels may provide a selective advantage in the presence of a preexisting immune response. CONCLUSIONS Experimental data in HRSV demonstrate that variation exists not only in gene-coding sequences but also in the signals that control gene expression. Thus alteration in the expression of key proteins provides a second type of antigenic "variation." A better understanding of these differences is critical to the development of an effective vaccine.
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Affiliation(s)
- Gail W Wertz
- Department of Microbiology, University of Alabama at Birmingham, USA.
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32
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Moudy RM, Harmon SB, Sullender WM, Wertz GW. Variations in transcription termination signals of human respiratory syncytial virus clinical isolates affect gene expression. Virology 2003; 313:250-60. [PMID: 12951037 DOI: 10.1016/s0042-6822(03)00299-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Human respiratory syncytial virus (HRSV) has a single-stranded, negative-sense RNA genome with 10 genes encoding 11 proteins. Sequences at the beginning of the HRSV genes are highly conserved; however, the gene end sequences vary around a semiconserved consensus sequence, and the nontranscribed intergenic regions vary in both length and sequence. The regions at the junctions between HRSV genes (the gene end sequence of an upstream gene, intergenic region, and the gene start sequence of a downstream gene) contain elements required for efficient termination of the upstream gene and transcription of the downstream gene. Previous studies have examined variation in the HRSV coding sequences, but none have systematically analyzed the noncoding transcriptional control regions for variability. We determined the gene start and gene end sequences of each of the 10 HRSV genes from 14 clinical isolates for variations from the sequence of the prototype A2 strain. No changes were found in any of the gene start sequences. Eight of the 10 gene end sequences, however, contained variations. Several of these, a U(4)-tract instead of a U(6)- or U(5)-tract at the M and SH gene ends, respectively, (U(4)A) and an A-to-G change at position four in the G gene end (A4G), were predicted to affect termination and were examined for their effects on transcription. The changes were found to inhibit transcriptional termination, resulting in increased polycistronic readthrough and correspondingly reduced initiation of the downstream monocistronic mRNA. Viruses with the A4G variant G gene end sequence produced less F protein than those with A2-like G gene end sequences. Examination of additional G gene end sequences available in GenBank revealed that the observed A4G variation was restricted to one phylogenetic lineage of HRSV. All viruses examined within this lineage possessed this variant G gene end sequence. The data presented show that the gene end sequences of naturally occurring HRSV clinical isolates vary from those of the prototypic A2 strain and that certain of these changes inhibit efficient transcriptional termination and downstream gene expression.
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Affiliation(s)
- Robin M Moudy
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
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33
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Begoña Ruiz-Argüello M, González-Reyes L, Calder LJ, Palomo C, Martín D, Saíz MJ, García-Barreno B, Skehel JJ, Melero JA. Effect of proteolytic processing at two distinct sites on shape and aggregation of an anchorless fusion protein of human respiratory syncytial virus and fate of the intervening segment. Virology 2002; 298:317-26. [PMID: 12127793 DOI: 10.1006/viro.2002.1497] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have examined the consequences of cleaving the fusion glycoprotein (F) of human respiratory syncytial virus (HRSV) at two distinct furin-recognition sites. Purified anchorless F is a mixture of unaggregated cone-shaped molecules and rosettes of lollipop-shaped spikes. The unaggregated molecules contain a proportion of uncleaved F0 and an intermediate, F(delta1-109), cleaved only at site I, residues 106-109. Inhibition of cleavage at site I, by two amino acid changes (R108N/R109N), reduces the proportion of aggregated molecules with a concomitant increase in the amount of unprocessed F0. Inhibition of cleavage at site II, residues 131-136, by deletion of four amino acids (delta131-134), abrogates aggregation of anchorless F and all molecules are seen as individual cone-shaped rods. In vitro cleavage of anchorless F, or mutant delta131-134, with trypsin at 4, 20, or 37 degrees C, under conditions in which cleavage at site II is complete in all molecules, leads to their aggregation in rosettes of lollipop-shaped spikes. Thus, cleavage at site II is required for the structural changes in anchorless F that lead to changes in shape and to aggregation. The segment between sites I and II, residues 110-136, is not associated with anchorless F in the supernatant of infected cell cultures, indicating that it is released from the processed protein when cleavage at sites I and II is completed.
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Affiliation(s)
- M Begoña Ruiz-Argüello
- Centro Nacional de Biología Fundamental, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
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34
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González-Reyes L, Ruiz-Argüello MB, García-Barreno B, Calder L, López JA, Albar JP, Skehel JJ, Wiley DC, Melero JA. Cleavage of the human respiratory syncytial virus fusion protein at two distinct sites is required for activation of membrane fusion. Proc Natl Acad Sci U S A 2001; 98:9859-64. [PMID: 11493675 PMCID: PMC55543 DOI: 10.1073/pnas.151098198] [Citation(s) in RCA: 178] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Preparations of purified full-length fusion (F) protein of human respiratory syncytial virus (HRSV) expressed in recombinant vaccinia-F infected cells, or of an anchorless mutant (F(TM(-))) lacking the C-terminal 50 amino acids secreted from vaccinia-F(TM(-))-infected cells contain a minor polypeptide that is an intermediate product of proteolytic processing of the F protein precursor F0. N-terminal sequencing of the intermediate demonstrated that it is generated by cleavage at a furin-motif, residues 106-109 of the F sequence. By contrast, the F1 N terminus derives from cleavage at residue 137 of F0 which is also C-terminal to a furin recognition site at residues 131-136. Site-directed mutagenesis indicates that processing of F0 protein involves independent cleavage at both sites. Both cleavages are required for the F protein to be active in membrane fusion as judged by syncytia formation, and they allow changes in F structure from cone- to lollipop-shaped spikes and the formation of rosettes by anchorless F.
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Affiliation(s)
- L González-Reyes
- Centro Nacional de Biología Fundamental, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
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35
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Calder LJ, González-Reyes L, García-Barreno B, Wharton SA, Skehel JJ, Wiley DC, Melero JA. Electron microscopy of the human respiratory syncytial virus fusion protein and complexes that it forms with monoclonal antibodies. Virology 2000; 271:122-31. [PMID: 10814577 DOI: 10.1006/viro.2000.0279] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Full-length fusion (F) glycoprotein of human respiratory syncytial virus (HRSV) and a truncated anchorless mutant lacking the C-terminal 50 amino acids were expressed from vaccinia recombinants and purified by immunoaffinity chromatography and sucrose gradient centrifugation. Electron microscopy of full-length F protein in the absence of detergents revealed micelles, (i.e., rosettes) containing two distinct types of protein rods, one cone-shaped and the other lollipop-shaped. Analysis of membrane anchorless F molecules indicated that they were similar to the cone-shaped rods and that rosettes, which they formed on storage, were made up of lollipop-shaped rods. The two forms of F protein may represent different structures that the molecule may adopt before and after activation for its role in membrane fusion. Studies of complexes of these structures with monoclonal antibodies of known specificity provide information on the three-dimensional organization of antigenic sites on the F protein and confirm the oligomeric structure, possibly trimeric, of both full-length F and membrane anchorless F.
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Affiliation(s)
- L J Calder
- National Institute for Medical Research, Mill Hill, London, NW7 1AA, United Kingdom
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36
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Sakurai H, Williamson RA, Crowe JE, Beeler JA, Poignard P, Bastidas RB, Chanock RM, Burton DR. Human antibody responses to mature and immature forms of viral envelope in respiratory syncytial virus infection: significance for subunit vaccines. J Virol 1999; 73:2956-62. [PMID: 10074145 PMCID: PMC104055 DOI: 10.1128/jvi.73.4.2956-2962.1999] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A number of antibodies generated during human respiratory syncytial virus (RSV) infection have been cloned by the phage library approach. Antibodies reactive with an immunodominant epitope on the F glycoprotein of this virus have a high affinity for affinity-purified F antigen. These antibodies, however, have a much lower affinity for mature F glycoprotein on the surface of infected cells and are nonneutralizing. In contrast, a potent neutralizing antibody has a high affinity for mature F protein but a much lower affinity for purified F protein or F protein in viral lysates. The data indicate that at least two F protein immunogens are produced during natural RSV infection: immature F, found in viral lysates, and mature F, found on infected cells or virions. Binding studies with polyclonal human immunoglobulin G suggest that the antibody responses to the two immunogens are of similar magnitudes. Competitive binding studies suggest that overlap between the responses is relatively limited. A mature envelope with an antigenic configuration different from that of the immature envelope has an evolutionary advantage in that the infecting virus is less subject to neutralization by the humoral response to the immature envelope that inevitably arises following lysis of infected cells. Subunit vaccines may be at a disadvantage because they most often resemble immature envelope molecules and ignore this aspect of viral evasion.
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Affiliation(s)
- H Sakurai
- Departments of Immunology, The Scripps Research Institute, La Jolla, California 92037, USA
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37
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López JA, Bustos R, Orvell C, Berois M, Arbiza J, García-Barreno B, Melero JA. Antigenic structure of human respiratory syncytial virus fusion glycoprotein. J Virol 1998; 72:6922-8. [PMID: 9658147 PMCID: PMC109907 DOI: 10.1128/jvi.72.8.6922-6928.1998] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
New series of escape mutants of human respiratory syncytial virus were prepared with monoclonal antibodies specific for the fusion (F) protein. Sequence changes selected in the escape mutants identified two new antigenic sites (V and VI) recognized by neutralizing antibodies and a group-specific site (I) in the F1 chain of the F molecule. The new epitopes, and previously identified antigenic sites, were incorporated into a refined prediction of secondary-structure motifs to generate a detailed antigenic map of the F glycoprotein.
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Affiliation(s)
- J A López
- Centro Nacional de Biología Fundamental, Instituto de Salud Carlos III, Majadahonda, 28220 Madrid, Spain
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38
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Werle B, Bourgeois C, Alexandre A, Massonneau V, Pothier P. Immune response to baculovirus expressed protein fragment amino acids 190-289 of respiratory syncytial virus (RSV) fusion protein. Vaccine 1998; 16:1127-30. [PMID: 9682369 DOI: 10.1016/s0264-410x(98)80109-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
At least two neutralizing epitopes have been identified in the amino acid (aa) sequence 190-289 of the RSV fusion protein. The authors expressed this region in insect cells (bF190-289) and compared the immune response to bF190-289 with that induced by baculovirus expressed full-length fusion protein (bF). As with bF, mice primed with bF190-289 produced exclusively antibodies of IgG1 isotype, generated neutralizing antibodies, reduced significantly the virus titer (about a half log10 reduction) after RSV challenge and induced a Helper T (Th) 2 cell response in mediastinal lymph node cells (MLNC) restimulated in vitro. Thus, the aa sequence 190-289 represents a major immunogenic region of the RSV fusion protein.
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Affiliation(s)
- B Werle
- Laboratoire de Microbiologie Médicale et Moléculaire, Facultés de Médecine et de Pharmacie, Dijon, France
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39
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Keles I, Woldehiwet Z, Murray RD. Vaccination with glutaraldehyde-fixed bovine respiratory syncytial virus (BRSV)-infected cells stimulates a better immune response in lambs than vaccination with heat-inactivated cell-free BRSV. Vaccine 1998; 16:1172-8. [PMID: 9682376 DOI: 10.1016/s0264-410x(98)80116-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The lamb model was used to investigate the possible protective effects of vaccination with inactivated viral antigens against experimental infection with bovine respiratory syncytial virus. Two groups of eight lambs were vaccinated with either glutaraldehyde-inactivated cell-associated virus or heat-inactivated cell-free virus and subsequently challenged with live virus, along with a group of naive lambs. The virus was shed for significantly longer periods, and the virus titres in nasal secretions were significantly higher in the group of naive lambs than in the two groups of vaccinated lambs. The period of virus-shedding in nasal secretions and virus titres was significantly lower (p < 0.01) in the group of lambs immunized with the cell-associated preparation. The same antigen stimulated better cellular immune responses as measured by virus-specific cytotoxicity or by virus-specific lymphocyte proliferation. However, priming with inactivated vaccines had no significant effect on lymphocyte responses to phytohaemagglutinin, which was found to be significantly reduced (p < 0.01) following challenge with live virus.
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Affiliation(s)
- I Keles
- University of Liverpool, Department of Veterinary Clinical Science and Animal Husbandry, Neston, S. Wirral, UK
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40
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Chargelegue D, Obeid OE, Hsu SC, Shaw MD, Denbury AN, Taylor G, Steward MW. A peptide mimic of a protective epitope of respiratory syncytial virus selected from a combinatorial library induces virus-neutralizing antibodies and reduces viral load in vivo. J Virol 1998; 72:2040-6. [PMID: 9499058 PMCID: PMC109497 DOI: 10.1128/jvi.72.3.2040-2046.1998] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/1997] [Accepted: 11/20/1997] [Indexed: 02/06/2023] Open
Abstract
Respiratory syncytial virus (RSV) is the most important cause of bronchiolitis and pneumonia in infants and young children worldwide. As yet, there is no effective vaccine against RSV infection, and previous attempts to develop a formalin-inactivated vaccine resulted in exacerbated disease in recipients subsequently exposed to the virus. In the work described here, a combinatorial solid-phase peptide library was screened with a protective monoclonal antibody (MAb 19) to identify peptide mimics (mimotopes) of a conserved and conformationally-determined epitope of RSV fusion (F) protein. Two sequences identified (S1 [HWYISKPQ] and S2 [HWYDAEVL]) reacted specifically with MAb 19 when they were presented as solid-phase peptides. Furthermore, after amino acid substitution analyses, three sequences derived from S1 (S1S [HWSISKPQ], S1K [KWYISKPQ], and S1P [HPYISKPQ]), presented as multiple antigen peptides (MAPs), also showed strong reactivity with MAb 19. The affinity constants of the binding of MAb 19, determined by surface plasmon resonance analyses, were 1.19 x 10(9) and 4.93 x 10(9) M(-1) for S1 and S1S, respectively. Immunization of BALB/c mice with these mimotopes, presented as MAPs, resulted in the induction of anti-peptide antibodies that inhibited the binding of MAb 19 to RSV and neutralized viral infection in vitro, with titers equivalent to those in sera from RSV-infected animals. Following RSV challenge of S1S mimotope-immunized mice, a 98.7% reduction in the titer of virus in the lungs was observed. Furthermore, there was a greatly reduced cell infiltration in the lungs of immunized mice compared to that in controls. These results indicate the potential of peptide mimotopes to protect against RSV infection without exacerbating pulmonary pathology.
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Affiliation(s)
- D Chargelegue
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, United Kingdom
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41
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Perez M, García-Barreno B, Melero JA, Carrasco L, Guinea R. Membrane permeability changes induced in Escherichia coli by the SH protein of human respiratory syncytial virus. Virology 1997; 235:342-51. [PMID: 9281514 DOI: 10.1006/viro.1997.8696] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The small hydrophobic (SH) protein of human respiratory syncytial virus (HRSV) has been efficiently expressed in Escherichia coli. In analogy to small hydrophobic proteins encoded by other RNA viruses, membrane permeability changes to low-molecular-weight compounds were detected in bacteria expressing HRSV SH protein. These changes implied, at least, the entry of both the protein synthesis inhibitor hygromycin B and the beta-galactoside substrate o-nitrophenyl-beta-d-galactopyranoside and the exit of preloaded [3H]uridine from bacterial cells. Site-directed mutagenesis indicated that the C-terminal end of SH is needed for induction of membrane permeability changes. In addition, amino acid substitution at residue 32 (Ile to Lys) abolished that activity. This was correlated with a drastic increase in SH electrophoretic mobility and a decrease of the predicted values of alpha-helix for all residues of the SH transmembrane domain. Other sequence changes have either partial effect or no effect on the membrane permeability changes induced by the SH protein. However, none of the mutations abrogated the association of SH protein with bacterial membranes, indicating that incorporation of SH protein to membranes is not sufficient to induce the observed changes. Membrane permeability changes then might provide a useful test for the identification of key amino acid residues in this unique HRSV gene product.
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Affiliation(s)
- M Perez
- Centro Nacional de Biología Fundamental, Instituto de Salud "Carlos III,", Madrid, Majadahonda, 28220, Spain
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42
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Chargelegue D, Obeid OE, Shaw DM, Denbury AN, Hobby P, Hsu SC, Steward MW. Peptide mimics of a conformationally constrained protective epitopes of respiratory syncytial virus fusion protein. Immunol Lett 1997; 57:15-7. [PMID: 9232419 DOI: 10.1016/s0165-2478(97)00045-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
AIMS To identify peptides that mimic (mimotopesi conformational and protective epitopes of RSV fusion protein and to assess their efficacy as immunogens and potential vaccines. MATERIAL AND METHODS An 8-mer solid-phase (TG resin) library was screened with a neutralising and protective RSV fusion protein specific monoclonal antibodies (Mab-19). After selection of positive beads, reactive sequences were identified by microsequencing and 8-mer peptides were synthesised. Improvement of binding was analysed by amino acid replacement using the SPOTs method. RESULTS Mabs were not able to bind to the free and soluble peptides, nor did these peptides induce anti-RSV specific antibodies. However, several peptides re-synthesised on a TG resin (to produce de-protected 8-mer peptides linked to the resin) or as SPOTs reacted specifically. Therefore it was critical to be able to reproduce this conformation in order to use these mimotopes as immunogens and potential vaccines. Using C-terminal constrained versions of the mimotopes, strong binding of one of the Mabs to the peptides was demonstrated by surface-plasmon resonance. Immunisation of Balb/c mice with these peptide-mimics produced anti-sera that: (1) reacted specifically with RSV; (2) inhibited the binding of the Mab to the virus; (3) neutralised RSV in vitro with high titres (range: 80-640); and (4) reduce significantly the viral load in the lungs of mice challenged with RSV (P < 0.01). CONCLUSIONS This report demonstrates for the first time that: (1) a protective epitope of the conserved RSV fusion protein can be mimicked by synthetic peptides; and (2) immunisations with these mimotopes induced specific anti-RSV neutralising antibodies and reduced viral load in vivo. These results represent a novel concept for the development of a vaccine against RSV.
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Affiliation(s)
- D Chargelegue
- London School of Hygiene and Tropical Medicine, Molecular Immunology Unit, UK.
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43
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Mufson MA, Stanek RJ. Identification of a variant subgroup A strain of respiratory syncytial virus. J Clin Microbiol 1996; 34:2493-6. [PMID: 8880506 PMCID: PMC229301 DOI: 10.1128/jcm.34.10.2493-2496.1996] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
During epidemiologic surveillance of children with respiratory syncytial virus (RSV) disease in Huntington, W.Va., we identified seven strains of a new variant subgroup A RSV (subgroup A-Var) by their reactions in an enzyme immunoassay with two anti-F monoclonal antibodies (MAbs) specific for two epitopes, F1 and F4, generated against the subgroup B RSV. The prototype strain of subgroup A and all other subgroup A field strains from that epidemiologic year failed to react with these two subgroup B MAbs. Additional enzyme immunoassays with 18 subgroup B anti-F MAbs specific for 14 epitopes showed that subgroup A-Var strains also reacted with a MAb specific for the subgroup B F2 epitope. In a radioimmune precipitation assay, the molecular size of the subgroup A-Var F2 subunit of the fusion (F) protein clearly differed from those of both prototype strains of subgroup A and subgroup B RSV. The molecular size of the F2 subunit of subgroup A-Var (24 kDa) was intermediate between the size of the F2 subunit of subgroup A (25 kDa) and that of subgroup B (23 kDa). However, the molecular sizes of the F1 subunits of both subgroup A and subgroup A-Var were identical (54 kDa) and slightly larger than those of the F1 subunits of both subgroups B1 and B2 (53 kDa). These data suggest that subgroup A-Var may represent a distinct RSV A subgroup, analogous to subgroup B1 and B2 RSV, and it is the first-identified naturally occurring subgroup A RSV with an F protein different from that of the prototype A RSV.
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Affiliation(s)
- M A Mufson
- Department of Medicine, Marshall University School of Medicine, Huntington, West Virginia 25703, USA.
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44
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Toiron C, López JA, Rivas G, Andreu D, Melero JA, Bruix M. Conformational studies of a short linear peptide corresponding to a major conserved neutralizing epitope of human respiratory syncytial virus fusion glycoprotein. Biopolymers 1996; 39:537-48. [PMID: 8837519 DOI: 10.1002/(sici)1097-0282(199610)39:4<537::aid-bip6>3.0.co;2-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The conformational properties of a 21-residue peptide, corresponding to amino acids 255 to 275 (F255-275) of the human respiratory syncytial virus fusion (F) glycoprotein have been studied by CD and nmr spectroscopy. This peptide includes residues 262, 268, and 272 of the F polypeptide that are essential for integrity of most epitopes that mapped into a major antigenic site of the F molecule. CD data indicate that F255-275 adopts a random coil conformation in aqueous solution at low peptide concentrations. However, as the concentration of peptide is increased, a higher percentage of peptide molecules adopts an organized structure. This effect can be more easily observed when trifluoroethanol (30%) is added to peptide solutions, giving rise to CD spectra that resemble those of alpha-helix structures. These conformational changes were confirmed by nmr spectroscopy. The nuclear Overhauser effects observed in 30% trifluoroethanol/ water together with the conformational H alpha chemical shift data allowed us to propose a structural model of helix-loop-helix for the peptide in solution. In addition, these helical regions contain the amino acid residues essential for epitope integrity in the native F molecule. These results give new insights into the antigenic structure of the respiratory syncytical virus F glycoprotein.
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Affiliation(s)
- C Toiron
- Instituto de Estructura de la Materia CSIC, Madrid, Spain
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45
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Plows DJ, Pringle CR. Variation in the fusion glycoprotein gene of human respiratory syncytial virus subgroup A. Virus Genes 1995; 11:37-45. [PMID: 8808333 DOI: 10.1007/bf01701660] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Six different genotypes (designated lineages SHL1-6) of human respiratory syncytial (RS) virus have been defined by partial nucleotide sequence analysis of the variable SH and the hypervariable G membrane protein genes, and by restriction fragment analysis of the conserved N protein gene of viruses isolated in south Birmingham. Viruses of very similar genotype appear to be present worldwide at the present time. We have determined the nucleotide sequences of the fusion protein genes of five viruses isolated in south Birmingham in the same year, but belonging to different lineages, and have compared them with the sequences of four subgroup A viruses isolated at earlier times from diverse localities. The sequence diversity of the F genes of these five viruses, as measured by nucleotide (94.5-98.5%) and inferred amino acid (97.0-99.3%) identifies, is comparable with that of the nine subgroup A viruses considered as a whole. No sequence changes occur in any of the sites of known epitopes. Comparison of the nine subgroup A sequences with the published sequences of a subgroup B strain and three bovine RS viruses confirms that the F protein sequences are most divergent in the F2 region.
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MESH Headings
- Amino Acid Sequence
- Antigens, Viral/chemistry
- Antigens, Viral/genetics
- Base Sequence
- Cells, Cultured
- DNA Primers/genetics
- DNA, Viral/genetics
- Genes, Viral
- Genetic Variation
- Genotype
- Humans
- Molecular Sequence Data
- Polymerase Chain Reaction
- Protein Conformation
- Respiratory Syncytial Virus, Bovine/genetics
- Respiratory Syncytial Virus, Human/classification
- Respiratory Syncytial Virus, Human/genetics
- Respiratory Syncytial Virus, Human/isolation & purification
- Sequence Homology, Amino Acid
- Viral Fusion Proteins/chemistry
- Viral Fusion Proteins/genetics
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Affiliation(s)
- D J Plows
- Biological Sciences Department, University of Warwick, Coventry, UK
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