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Jones HG, Ritschel T, Pascual G, Brakenhoff JPJ, Keogh E, Furmanova-Hollenstein P, Lanckacker E, Wadia JS, Gilman MSA, Williamson RA, Roymans D, van ‘t Wout AB, Langedijk JP, McLellan JS. Structural basis for recognition of the central conserved region of RSV G by neutralizing human antibodies. PLoS Pathog 2018; 14:e1006935. [PMID: 29509814 PMCID: PMC5856423 DOI: 10.1371/journal.ppat.1006935] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Revised: 03/16/2018] [Accepted: 02/12/2018] [Indexed: 11/19/2022] Open
Abstract
Respiratory syncytial virus (RSV) is a major cause of severe lower respiratory tract infections in infants and the elderly, and yet there remains no effective treatment or vaccine. The surface of the virion is decorated with the fusion glycoprotein (RSV F) and the attachment glycoprotein (RSV G), which binds to CX3CR1 on human airway epithelial cells to mediate viral attachment and subsequent infection. RSV G is a major target of the humoral immune response, and antibodies that target the central conserved region of G have been shown to neutralize both subtypes of RSV and to protect against severe RSV disease in animal models. However, the molecular underpinnings for antibody recognition of this region have remained unknown. Therefore, we isolated two human antibodies directed against the central conserved region of RSV G and demonstrated that they neutralize RSV infection of human bronchial epithelial cell cultures in the absence of complement. Moreover, the antibodies protected cotton rats from severe RSV disease. Both antibodies bound with high affinity to a secreted form of RSV G as well as to a peptide corresponding to the unglycosylated central conserved region. High-resolution crystal structures of each antibody in complex with the G peptide revealed two distinct conformational epitopes that require proper folding of the cystine noose located in the C-terminal part of the central conserved region. Comparison of these structures with the structure of fractalkine (CX3CL1) alone or in complex with a viral homolog of CX3CR1 (US28) suggests that RSV G would bind to CX3CR1 in a mode that is distinct from that of fractalkine. Collectively, these results build on recent studies demonstrating the importance of RSV G in antibody-mediated protection from severe RSV disease, and the structural information presented here should guide the development of new vaccines and antibody-based therapies for RSV.
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Affiliation(s)
- Harrison G. Jones
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Tina Ritschel
- Janssen Vaccines & Prevention, Leiden, The Netherlands
| | - Gabriel Pascual
- Janssen Prevention Center, Janssen Pharmaceutical Companies of Johnson and Johnson, San Diego, California, United States of America
| | - Just P. J. Brakenhoff
- Janssen Prevention Center, Janssen Vaccines & Prevention B.V., Leiden, The Netherlands
| | - Elissa Keogh
- Janssen Prevention Center, Janssen Pharmaceutical Companies of Johnson and Johnson, San Diego, California, United States of America
| | | | - Ellen Lanckacker
- Janssen Infectious Diseases, Janssen Pharmaceutica NV, Beerse, Belgium
| | | | - Morgan S. A. Gilman
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - R. Anthony Williamson
- Janssen Prevention Center, Janssen Pharmaceutical Companies of Johnson and Johnson, London, United Kingdom
| | - Dirk Roymans
- Janssen Infectious Diseases, Janssen Pharmaceutica NV, Beerse, Belgium
| | | | | | - Jason S. McLellan
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
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152
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Respiratory Syncytial Virus: Targeting the G Protein Provides a New Approach for an Old Problem. J Virol 2018; 92:JVI.01302-17. [PMID: 29118126 DOI: 10.1128/jvi.01302-17] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Respiratory syncytial virus (RSV) is a major cause of lower respiratory tract infection (LRTI) annually affecting >2 million children in the United States <5 years old. In the elderly (>65 years old), RSV results in ∼175,000 hospitalizations annually in the United States with a worldwide incidence of ∼34 million. There is no approved RSV vaccine, and treatments are limited. Recently, a phase 3 trial in the elderly using a recombinant RSV F protein vaccine failed to meet its efficacy objectives, namely, prevention of moderate-to-severe RSV-associated LRTI and reduced incidence of acute respiratory disease. Moreover, a recent phase 3 trial evaluating suptavumab (REGN2222), an antibody to RSV F protein, did not meet its primary endpoint of preventing medically attended RSV infections in preterm infants. Despite these setbacks, numerous efforts targeting the RSV F protein with vaccines, antibodies, and small molecules continue based on the commercial success of a monoclonal antibody (MAb) against the RSV F protein (palivizumab). As the understanding of RSV biology has improved, the other major coat protein, the RSV G protein, has reemerged as an alternative target reflecting progress in understanding its roles in infecting bronchial epithelial cells and in altering the host immune response. In mouse models, a high-affinity, strain-independent human MAb to the RSV G protein has shown potent direct antiviral activity combined with the alleviation of virus-induced immune system effects that contribute to disease pathology. This MAb, being prepared for clinical trials, provides a qualitatively new approach to managing RSV for populations not eligible for prophylaxis with palivizumab.
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153
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Capella C, Chaiwatpongsakorn S, Gorrell E, Risch ZA, Ye F, Mertz SE, Johnson SM, Moore-Clingenpeel M, Ramilo O, Mejias A, Peeples ME. Prefusion F, Postfusion F, G Antibodies, and Disease Severity in Infants and Young Children With Acute Respiratory Syncytial Virus Infection. J Infect Dis 2017; 216:1398-1406. [PMID: 29029312 PMCID: PMC5853469 DOI: 10.1093/infdis/jix489] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 09/14/2017] [Indexed: 12/12/2022] Open
Abstract
Background Respiratory syncytial virus (RSV) is the most frequent cause of lower respiratory tract infection in infants. Maternally derived RSV-specific antibodies play a role in protection against RSV infection in early life, but data regarding the concentration and specificity of those antibodies are incomplete. Methods We prospectively enrolled a cohort of previously healthy infants and young children hospitalized (n = 45) or evaluated as outpatients (n = 20) for RSV infection, and healthy noninfected age-matched controls (n = 18). Serum samples were obtained at enrollment to quantify the concentrations and neutralizing activity of serum immunoglobulin G antibodies to the RSV prefusion (pre-F), postfusion (post-F), and G glycoproteins. We also assessed the associations between antibody concentrations and clinical disease severity. Results Concentrations of pre-F antibodies were ≥3-fold higher than post-F antibodies and >30-fold higher than G antibodies in serum from infants with acute RSV infection. Antibody concentrations and neutralizing activity inversely correlated with age. The pre-F antibodies displayed the greatest neutralizing activity (55%-100%), followed by G (0%-45%), and post-F (0%-29%) antibodies. Higher concentrations of pre-F and G antibodies, but not post-F antibodies, were associated with lower clinical disease severity scores. Conclusions Maternal antibodies directed to pre-F, followed by antibodies directed to G, can modulate RSV disease severity in young infants.
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Affiliation(s)
- Cristina Capella
- Center for Vaccines and Immunity, Nationwide Children’s Hospital, Columbus
| | | | - Erin Gorrell
- Center for Vaccines and Immunity, Nationwide Children’s Hospital, Columbus
| | - Zachary A Risch
- Center for Vaccines and Immunity, Nationwide Children’s Hospital, Columbus
| | - Fang Ye
- Center for Vaccines and Immunity, Nationwide Children’s Hospital, Columbus
| | - Sara E Mertz
- Center for Vaccines and Immunity, Nationwide Children’s Hospital, Columbus
| | - Sara M Johnson
- Center for Vaccines and Immunity, Nationwide Children’s Hospital, Columbus
| | | | - Octavio Ramilo
- Center for Vaccines and Immunity, Nationwide Children’s Hospital, Columbus
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus
| | - Asuncion Mejias
- Center for Vaccines and Immunity, Nationwide Children’s Hospital, Columbus
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus
| | - Mark E Peeples
- Center for Vaccines and Immunity, Nationwide Children’s Hospital, Columbus
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus
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154
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Magro-Lopez E, Guijarro T, Martinez I, Martin-Vicente M, Liste I, Zambrano A. A Two-Dimensional Human Minilung System (Model) for Respiratory Syncytial Virus Infections. Viruses 2017; 9:v9120379. [PMID: 29232863 PMCID: PMC5744153 DOI: 10.3390/v9120379] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 12/04/2017] [Accepted: 12/08/2017] [Indexed: 12/26/2022] Open
Abstract
Human respiratory syncytial virus (HRSV) is a major cause of serious pediatric respiratory diseases that lacks effective vaccine or specific therapeutics. Although our understanding about HRSV biology has dramatically increased during the last decades, the need for adequate models of HRSV infection is compelling. We have generated a two-dimensional minilung from human embryonic stem cells (hESCs). The differentiation protocol yielded at least six types of lung and airway cells, although it is biased toward the generation of distal cells. We show evidence of HRSV replication in lung cells, and the induction of innate and proinflammatory responses, thus supporting its use as a model for the study of HRSV-host interactions.
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Affiliation(s)
- Esmeralda Magro-Lopez
- Functional Unit for Research into Chronic Diseases (UFIEC), Institute of Health Carlos III, 28220 Madrid, Spain.
| | - Trinidad Guijarro
- Functional Unit for Research into Chronic Diseases (UFIEC), Institute of Health Carlos III, 28220 Madrid, Spain.
| | - Isidoro Martinez
- Spanish National Center for Microbiology (CNM), Institute of Health Carlos III, 28220 Madrid, Spain.
| | - Maria Martin-Vicente
- Spanish National Center for Microbiology (CNM), Institute of Health Carlos III, 28220 Madrid, Spain.
| | - Isabel Liste
- Functional Unit for Research into Chronic Diseases (UFIEC), Institute of Health Carlos III, 28220 Madrid, Spain.
| | - Alberto Zambrano
- Functional Unit for Research into Chronic Diseases (UFIEC), Institute of Health Carlos III, 28220 Madrid, Spain.
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155
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Abstract
The viral attachment protein of RSV has many surprising features, especially its mimicry of fractalkine (CX3CL1). Zhivaki et al. (2017) now show that, in addition to using this homology to attach to ciliated cells, it activates human neonatal regulatory B cells, thereby inhibiting immunological responses.
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Affiliation(s)
- Peter J M Openshaw
- Respiratory Sciences, National Heart and Lung Institute, Imperial College London, St Mary's Campus, Norfolk Place, London W2 1PG, UK.
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156
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Jartti T, Gern JE. Role of viral infections in the development and exacerbation of asthma in children. J Allergy Clin Immunol 2017; 140:895-906. [PMID: 28987219 PMCID: PMC7172811 DOI: 10.1016/j.jaci.2017.08.003] [Citation(s) in RCA: 277] [Impact Index Per Article: 39.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 08/03/2017] [Accepted: 08/22/2017] [Indexed: 12/31/2022]
Abstract
Viral infections are closely linked to wheezing illnesses in children of all ages. Respiratory syncytial virus (RSV) is the main causative agent of bronchiolitis, whereas rhinovirus (RV) is most commonly detected in wheezing children thereafter. Severe respiratory illness induced by either of these viruses is associated with subsequent development of asthma, and the risk is greatest for young children who wheeze with RV infections. Whether viral illnesses actually cause asthma is the subject of intense debate. RSV-induced wheezing illnesses during infancy influence respiratory health for years. There is definitive evidence that RSV-induced bronchiolitis can damage the airways to promote airway obstruction and recurrent wheezing. RV likely causes less structural damage and yet is a significant contributor to wheezing illnesses in young children and in the context of asthma. For both viruses, interactions between viral virulence factors, personal risk factors (eg, genetics), and environmental exposures (eg, airway microbiome) promote more severe wheezing illnesses and the risk for progression to asthma. In addition, allergy and asthma are major risk factors for more frequent and severe RV-related illnesses. Treatments that inhibit inflammation have efficacy for RV-induced wheezing, whereas the anti-RSV mAb palivizumab decreases the risk of severe RSV-induced illness and subsequent recurrent wheeze. Developing a greater understanding of personal and environmental factors that promote more severe viral illnesses might lead to new strategies for the prevention of viral wheezing illnesses and perhaps reduce the subsequent risk for asthma.
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Affiliation(s)
- Tuomas Jartti
- Department of Paediatrics, Turku University Hospital and University of Turku, Turku, Finland.
| | - James E Gern
- Departments of Pediatrics and Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wis
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157
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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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158
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Respiratory Syncytial Virus: Infection, Detection, and New Options for Prevention and Treatment. Clin Microbiol Rev 2017; 30:277-319. [PMID: 27903593 DOI: 10.1128/cmr.00010-16] [Citation(s) in RCA: 342] [Impact Index Per Article: 48.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Respiratory syncytial virus (RSV) infection is a significant cause of hospitalization of children in North America and one of the leading causes of death of infants less than 1 year of age worldwide, second only to malaria. Despite its global impact on human health, there are relatively few therapeutic options available to prevent or treat RSV infection. Paradoxically, there is a very large volume of information that is constantly being refined on RSV replication, the mechanisms of RSV-induced pathology, and community transmission. Compounding the burden of acute RSV infections is the exacerbation of preexisting chronic airway diseases and the chronic sequelae of RSV infection. A mechanistic link is even starting to emerge between asthma and those who suffer severe RSV infection early in childhood. In this article, we discuss developments in the understanding of RSV replication, pathogenesis, diagnostics, and therapeutics. We attempt to reconcile the large body of information on RSV and why after many clinical trials there is still no efficacious RSV vaccine and few therapeutics.
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159
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Das S, Raundhal M, Chen J, Oriss TB, Huff R, Williams JV, Ray A, Ray P. Respiratory syncytial virus infection of newborn CX3CR1-deficient mice induces a pathogenic pulmonary innate immune response. JCI Insight 2017; 2:94605. [PMID: 28878128 DOI: 10.1172/jci.insight.94605] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 07/25/2017] [Indexed: 12/19/2022] Open
Abstract
Respiratory syncytial virus (RSV) infects almost all infants by 2 years of age, and severe bronchiolitis resulting from RSV infection is the primary cause of hospitalization in the first year of life. Among infants hospitalized due to RSV-induced bronchiolitis, those with a specific mutation in the chemokine receptor CX3CR1, which severely compromises binding of its ligand CX3CL1, were at a higher risk for more severe viral bronchiolitis than those without the mutation. Here, we show that RSV infection of newborn mice deficient in CX3CR1 leads to significantly greater neutrophilic inflammation in the lungs, accompanied by an increase in mucus production compared with that induced in WT mice. Analysis of innate and adaptive immune responses revealed an early increase in the number of IL-17+ γδ T cells in CX3CR1-deficient mice that outnumbered IFN-γ+ γδ T cells as well as IFN-γ+ NK cells, IFN-γ being host protective in the context of RSV infection. This bias toward IL-17+ γδ T cells persisted at a later time. The lungs of CX3CR1-deficient mice expressed higher levels of IL-1β mRNA and protein, and blockade of IL-1β signaling using IL-1 receptor antagonist significantly reduced the number of IL-17+ γδ T cells in the lungs of infected mice. Blockade of IL-17RC abolished RSV-induced lung pathology in infected CX3CR1-deficient mice. We propose that, in infants harboring mutant CX3CR1, targeting the IL-17R may minimize disease severity and hospitalization in early life.
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Affiliation(s)
- Sudipta Das
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Mahesh Raundhal
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Jie Chen
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Timothy B Oriss
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Rachael Huff
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - John V Williams
- Division of Infectious Diseases, Department of Pediatrics, Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Anuradha Ray
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Prabir Ray
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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160
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Canedo-Marroquín G, Acevedo-Acevedo O, Rey-Jurado E, Saavedra JM, Lay MK, Bueno SM, Riedel CA, Kalergis AM. Modulation of Host Immunity by Human Respiratory Syncytial Virus Virulence Factors: A Synergic Inhibition of Both Innate and Adaptive Immunity. Front Cell Infect Microbiol 2017; 7:367. [PMID: 28861397 PMCID: PMC5561764 DOI: 10.3389/fcimb.2017.00367] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 07/31/2017] [Indexed: 01/27/2023] Open
Abstract
The Human Respiratory Syncytial Virus (hRSV) is a major cause of acute lower respiratory tract infections (ARTIs) and high rates of hospitalizations in children and in the elderly worldwide. Symptoms of hRSV infection include bronchiolitis and pneumonia. The lung pathology observed during hRSV infection is due in part to an exacerbated host immune response, characterized by immune cell infiltration to the lungs. HRSV is an enveloped virus, a member of the Pneumoviridae family, with a non-segmented genome and negative polarity-single RNA that contains 10 genes encoding for 11 proteins. These include the Fusion protein (F), the Glycoprotein (G), and the Small Hydrophobic (SH) protein, which are located on the virus surface. In addition, the Nucleoprotein (N), Phosphoprotein (P) large polymerase protein (L) part of the RNA-dependent RNA polymerase complex, the M2-1 protein as a transcription elongation factor, the M2-2 protein as a regulator of viral transcription and (M) protein all of which locate inside the virion. Apart from the structural proteins, the hRSV genome encodes for the non-structural 1 and 2 proteins (NS1 and NS2). HRSV has developed different strategies to evade the host immunity by means of the function of some of these proteins that work as virulence factors to improve the infection in the lung tissue. Also, hRSV NS-1 and NS-2 proteins have been shown to inhibit the activation of the type I interferon response. Furthermore, the hRSV nucleoprotein has been shown to inhibit the immunological synapsis between the dendritic cells and T cells during infection, resulting in an inefficient T cell activation. Here, we discuss the hRSV virulence factors and the host immunological features raised during infection with this virus.
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Affiliation(s)
- Gisela Canedo-Marroquín
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de ChileSantiago, Chile
| | - Orlando Acevedo-Acevedo
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de ChileSantiago, Chile
| | - Emma Rey-Jurado
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de ChileSantiago, Chile
| | - Juan M Saavedra
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de ChileSantiago, Chile
| | - Margarita K Lay
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de ChileSantiago, Chile.,Departamento de Biotecnología, Facultad de Ciencias del Mar y Recursos Biológicos, Universidad de AntofagastaAntofagasta, Chile
| | - Susan M Bueno
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de ChileSantiago, Chile
| | - Claudia A Riedel
- Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas y Medicina, Universidad Andres Bello, Millennium Institute on Immunology and ImmunotherapySantiago, Chile
| | - Alexis M Kalergis
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de ChileSantiago, Chile.,Departamento de Endocrinología, Facultad de Medicina, Pontificia Universidad Católica de ChileSantiago, Chile
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161
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Whelan JN, Reddy KD, Uversky VN, Teng MN. Functional correlations of respiratory syncytial virus proteins to intrinsic disorder. MOLECULAR BIOSYSTEMS 2017; 12:1507-26. [PMID: 27062995 DOI: 10.1039/c6mb00122j] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Protein intrinsic disorder is an important characteristic demonstrated by the absence of higher order structure, and is commonly detected in multifunctional proteins encoded by RNA viruses. Intrinsically disordered regions (IDRs) of proteins exhibit high flexibility and solvent accessibility, which permit several distinct protein functions, including but not limited to binding of multiple partners and accessibility for post-translational modifications. IDR-containing viral proteins can therefore execute various functional roles to enable productive viral replication. Respiratory syncytial virus (RSV) is a globally circulating, non-segmented, negative sense (NNS) RNA virus that causes severe lower respiratory infections. In this study, we performed a comprehensive evaluation of predicted intrinsic disorder of the RSV proteome to better understand the functional role of RSV protein IDRs. We included 27 RSV strains to sample major RSV subtypes and genotypes, as well as geographic and temporal isolate differences. Several types of disorder predictions were applied to the RSV proteome, including per-residue (PONDR®-FIT and PONDR® VL-XT), binary (CH, CDF, CH-CDF), and disorder-based interactions (ANCHOR and MoRFpred). We classified RSV IDRs by size, frequency and function. Finally, we determined the functional implications of RSV IDRs by mapping predicted IDRs to known functional domains of each protein. Identification of RSV IDRs within functional domains improves our understanding of RSV pathogenesis in addition to providing potential therapeutic targets. Furthermore, this approach can be applied to other NNS viruses that encode essential multifunctional proteins for the elucidation of viral protein regions that can be manipulated for attenuation of viral replication.
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Affiliation(s)
- Jillian N Whelan
- Division of Allergy and Immunology, Department of Internal Medicine, and the Joy McCann Culverhouse Airway Diseases Research Center, University of South Florida Morsani College of Medicine, Tampa, FL, USA.
| | - Krishna D Reddy
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA
| | - Vladimir N Uversky
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA and Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA and Institute for Biological Instrumentation, Russian Academy of Sciences, 142292 Pushchino, Moscow Region, Russia
| | - Michael N Teng
- Division of Allergy and Immunology, Department of Internal Medicine, and the Joy McCann Culverhouse Airway Diseases Research Center, University of South Florida Morsani College of Medicine, Tampa, FL, USA.
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162
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The Central Conserved Region (CCR) of Respiratory Syncytial Virus (RSV) G Protein Modulates Host miRNA Expression and Alters the Cellular Response to Infection. Vaccines (Basel) 2017; 5:vaccines5030016. [PMID: 28671606 PMCID: PMC5620547 DOI: 10.3390/vaccines5030016] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 06/23/2017] [Accepted: 06/28/2017] [Indexed: 12/27/2022] Open
Abstract
Respiratory Syncytial Virus (RSV) infects respiratory epithelial cells and deregulates host gene expression by many mechanisms including expression of RSV G protein (RSV G). RSV G protein encodes a central conserved region (CCR) containing a CX3C motif that functions as a fractalkine mimic. Disruption of the CX3C motif (a.a. 182-186) located in the CCR of the G protein has been shown to affect G protein function in vitro and the severity of RSV disease pathogenesis in vivo. We show that infection of polarized Calu3 respiratory cells with recombinant RSV having point mutations in Cys173 and 176 (C173/176S) (rA2-GC12), or Cys186 (C186S) (rA2-GC4) is associated with a decline in the integrity of polarized Calu-3 cultures and decreased virus production. This is accompanied with downregulation of miRNAs let-7f and miR-24 and upregulation of interferon lambda (IFNλ), a primary antiviral cytokine for RSV in rA2-GC12/rA2-GC4 infected cells. These results suggest that residues in the cysteine noose region of RSV G protein can modulate IFN λ expression accompanied by downregulation of miRNAs, and are important for RSV G protein function and targeting.
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163
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Jorquera PA, Tripp RA. Respiratory syncytial virus: prospects for new and emerging therapeutics. Expert Rev Respir Med 2017; 11:609-615. [PMID: 28574729 DOI: 10.1080/17476348.2017.1338567] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
INTRODUCTION Respiratory syncytial virus (RSV) is the major cause of lower respiratory tract infections (LRTI) in infants, the elderly, and the immunocompromised. Although the development of a RSV vaccine has been a priority for >50 years, there is still no vaccine available. Treatment of RSV LRTI has remained mostly supportive, i.e. hydration and oxygenation. Palivizumab and ribavirin are the only options currently available for prevention and treatment of RSV infection, but evidence suggests that they are not fully effective. This creates a significant unmet medical need for new therapeutics for prevention and treatment of RSV worldwide. Areas covered: This article reviews the antiviral drugs and monoclonal antibodies (mAb) for RSV that are in different stages of clinical development. Expert commentary: Over the last 10 years, new antiviral drugs and mAb have shown clinical promise against RSV, and may become available in the coming years. Although the RSV fusion protein has been the most popular target for inhibitors and mAbs, new approaches targeting other viral proteins have shown promising results. To overcome the emergence of RSV escape mutants, combination antiviral therapy may be explored in the future.
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Affiliation(s)
- Patricia A Jorquera
- a Department of Infectious Disease, College of Veterinary Medicine , University of Georgia , Athens , GA , USA
| | - Ralph A Tripp
- a Department of Infectious Disease, College of Veterinary Medicine , University of Georgia , Athens , GA , USA
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Boyoglu-Barnum S, Todd SO, Meng J, Barnum TR, Chirkova T, Haynes LM, Jadhao SJ, Tripp RA, Oomens AG, Moore ML, Anderson LJ. Mutating the CX3C Motif in the G Protein Should Make a Live Respiratory Syncytial Virus Vaccine Safer and More Effective. J Virol 2017; 91:e02059-16. [PMID: 28275196 PMCID: PMC5411601 DOI: 10.1128/jvi.02059-16] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 02/20/2017] [Indexed: 12/24/2022] Open
Abstract
Respiratory syncytial virus (RSV) belongs to the family Paramyxoviridae and is the single most important cause of serious lower respiratory tract infections in young children, yet no highly effective treatment or vaccine is available. Through a CX3C chemokine motif (182CWAIC186) in the G protein, RSV binds to the corresponding chemokine receptor, CX3CR1. Since RSV binding to CX3CR1 contributes to disease pathogenesis, we investigated whether a mutation in the CX3C motif by insertion of an alanine, A186, within the CX3C motif, mutating it to CX4C (182CWAIAC187), which is known to block binding to CX3CR1, might decrease disease. We studied the effect of the CX4C mutation in two strains of RSV (A2 and r19F) in a mouse challenge model. We included RSV r19F because it induces mucus production and airway resistance, two manifestations of RSV infection in humans, in mice. Compared to wild-type (wt) virus, mice infected with CX4C had a 0.7 to 1.2 log10-fold lower virus titer in the lung at 5 days postinfection (p.i.) and had markedly reduced weight loss, pulmonary inflammatory cell infiltration, mucus production, and airway resistance after challenge. This decrease in disease was not dependent on decrease in virus replication but did correspond to a decrease in pulmonary Th2 and inflammatory cytokines. Mice infected with CX4C viruses also had higher antibody titers and a Th1-biased T cell memory response at 75 days p.i. These results suggest that the CX4C mutation in the G protein could improve the safety and efficacy of a live attenuated RSV vaccine.IMPORTANCE RSV binds to the corresponding chemokine receptor, CX3CR1, through a CX3C chemokine motif (182CWAIC186) in the G protein. RSV binding to CX3CR1 contributes to disease pathogenesis; therefore, we investigated whether a mutation in the CX3C motif by insertion of an alanine, A186, within the CX3C motif, mutating it to CX4C (182CWAIAC187), known to block binding to CX3CR1, might decrease disease. The effect of this mutation and treatment with the F(ab')2 form of the anti-RSV G 131-2G monoclonal antibody (MAb) show that mutating the CX3C motif to CX4C blocks much of the disease and immune modulation associated with the G protein and should improve the safety and efficacy of a live attenuated RSV vaccine.
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MESH Headings
- Animals
- Antibodies, Viral/blood
- Antibodies, Viral/immunology
- Chemokines, CX3C/genetics
- Chemokines, CX3C/immunology
- Chemokines, CX3C/metabolism
- Female
- GTP-Binding Proteins/chemistry
- GTP-Binding Proteins/genetics
- GTP-Binding Proteins/immunology
- Humans
- Immunologic Memory
- Lung/virology
- Mice
- Mice, Inbred BALB C
- Mutation
- Protein Interaction Domains and Motifs
- Respiratory Syncytial Virus Infections/immunology
- Respiratory Syncytial Virus Vaccines/adverse effects
- Respiratory Syncytial Virus Vaccines/chemistry
- Respiratory Syncytial Virus Vaccines/genetics
- Respiratory Syncytial Virus Vaccines/immunology
- Respiratory Syncytial Virus, Human/genetics
- Respiratory Syncytial Virus, Human/immunology
- Respiratory Syncytial Virus, Human/physiology
- Th1 Cells
- Th2 Cells
- Vaccines, Attenuated/chemistry
- Vaccines, Attenuated/genetics
- Vaccines, Attenuated/immunology
- Virus Replication
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Affiliation(s)
- S Boyoglu-Barnum
- Emory University Department of Pediatrics and Children's Healthcare of Atlanta, Atlanta, Georgia, USA
| | - S O Todd
- Emory University Department of Pediatrics and Children's Healthcare of Atlanta, Atlanta, Georgia, USA
| | - J Meng
- Emory University Department of Pediatrics and Children's Healthcare of Atlanta, Atlanta, Georgia, USA
| | - T R Barnum
- University of Georgia, Odum School of Ecology, Athens, Georgia, USA
| | - T Chirkova
- Emory University Department of Pediatrics and Children's Healthcare of Atlanta, Atlanta, Georgia, USA
| | - L M Haynes
- Division of Viral Diseases, National Center for Immunization and Respiratory Diseases, CDC, Atlanta, Georgia, USA
| | - S J Jadhao
- Emory University Department of Pediatrics and Children's Healthcare of Atlanta, Atlanta, Georgia, USA
| | - R A Tripp
- University of Georgia, Department of Infectious Diseases, Animal Health Research Center, Athens, Georgia, USA
| | - A G Oomens
- Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, Oklahoma, USA
| | - M L Moore
- Emory University Department of Pediatrics and Children's Healthcare of Atlanta, Atlanta, Georgia, USA
| | - L J Anderson
- Emory University Department of Pediatrics and Children's Healthcare of Atlanta, Atlanta, Georgia, USA
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165
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A Single-Dose Recombinant Parainfluenza Virus 5-Vectored Vaccine Expressing Respiratory Syncytial Virus (RSV) F or G Protein Protected Cotton Rats and African Green Monkeys from RSV Challenge. J Virol 2017; 91:JVI.00066-17. [PMID: 28298602 DOI: 10.1128/jvi.00066-17] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 03/08/2017] [Indexed: 12/21/2022] Open
Abstract
Human respiratory syncytial virus (RSV) is a common cause of severe respiratory disease among infants, immunocompromised individuals, and the elderly. No licensed vaccine is currently available. In this study, we evaluated two parainfluenza virus 5 (PIV5)-vectored vaccines expressing RSV F (PIV5/F) or G (PIV5/G) protein in the cotton rat and African green monkey models for their replication, immunogenicity, and efficacy of protection against RSV challenge. Following a single intranasal inoculation, both animal species shed the vaccine viruses for a limited time but without noticeable clinical symptoms. In cotton rats, the vaccines elicited RSV F- or G-specific serum antibodies and conferred complete lung protection against RSV challenge at doses as low as 103 PFU. Neither vaccine produced the enhanced lung pathology observed in animals immunized with formalin-inactivated RSV. In African green monkeys, vaccine-induced serum and mucosal antibody responses were readily detected, as well. PIV5/F provided nearly complete protection against RSV infection in the upper and lower respiratory tract at a dose of 106 PFU of vaccine. At the same dose levels, PIV5/G was less efficacious. Both PIV5/F and PIV5/G were also able to boost neutralization titers in RSV-preexposed African green monkeys. Overall, our data indicated that PIV5/F is a promising RSV vaccine candidate.IMPORTANCE A safe and efficacious respiratory syncytial virus (RSV) vaccine remains elusive. We tested the recombinant parainfluenza virus 5 (PIV5) vectors expressing RSV glycoproteins for their immunogenicity and protective efficacy in cotton rats and African green monkeys, which are among the best available animal models to study RSV infection. In both species, a single dose of intranasal immunization with PIV5-vectored vaccines was able to produce systemic and local immunity and to protect animals from RSV challenge. The vaccines could also boost RSV neutralization antibody titers in African green monkeys that had been infected previously. Our data suggest that PIV5-vectored vaccines could potentially protect both the pediatric and elderly populations and support continued development of the vector platform.
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166
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Broadly Reactive Anti-Respiratory Syncytial Virus G Antibodies from Exposed Individuals Effectively Inhibit Infection of Primary Airway Epithelial Cells. J Virol 2017; 91:JVI.02357-16. [PMID: 28275185 DOI: 10.1128/jvi.02357-16] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 02/27/2017] [Indexed: 11/20/2022] Open
Abstract
Respiratory syncytial virus (RSV) causes severe respiratory disease in young children. Antibodies specific for the RSV prefusion F protein have guided RSV vaccine research, and in human serum, these antibodies contribute to >90% of the neutralization response; however, detailed insight into the composition of the human B cell repertoire against RSV is still largely unknown. In order to study the B cell repertoire of three healthy donors for specificity against RSV, CD27+ memory B cells were isolated and immortalized using BCL6 and Bcl-xL. Of the circulating memory B cells, 0.35% recognized RSV-A2-infected cells, of which 59% were IgA-expressing cells and 41% were IgG-expressing cells. When we generated monoclonal B cells selected for high binding to RSV-infected cells, 44.5% of IgG-expressing B cells and 56% of IgA-expressing B cells reacted to the F protein, while, unexpectedly, 41.5% of IgG-expressing B cells and 44% of IgA expressing B cells reacted to the G protein. Analysis of the G-specific antibodies revealed that 4 different domains on the G protein were recognized. These epitopes predicted cross-reactivity between RSV strain A (RSV-A) and RSV-B and matched the potency of antibodies to neutralize RSV in HEp-2 cells and in primary epithelial cell cultures. G-specific antibodies were also able to induce antibody-dependent cellular cytotoxicity and antibody-dependent cellular phagocytosis of RSV-A2-infected cells. However, these processes did not seem to depend on a specific epitope. In conclusion, healthy adults harbor a diverse repertoire of RSV glycoprotein-specific antibodies with a broad range of effector functions that likely play an important role in antiviral immunity.IMPORTANCE Human RSV remains the most common cause of severe lower respiratory tract disease in premature babies, young infants, the elderly, and immunocompromised patients and plays an important role in asthma exacerbations. In developing countries, RSV lower respiratory tract disease has a high mortality. Without an effective vaccine, only passive immunization with palivizumab is approved for prophylactic treatment. However, highly potent RSV-specific monoclonal antibodies could potentially serve as a therapeutic treatment and contribute to disease control and mortality reduction. In addition, these antibodies could guide further vaccine development. In this study, we isolated and characterized several novel antibodies directed at the RSV G protein. This information can add to our understanding and treatment of RSV disease.
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167
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Openshaw PJ, Chiu C, Culley FJ, Johansson C. Protective and Harmful Immunity to RSV Infection. Annu Rev Immunol 2017; 35:501-532. [DOI: 10.1146/annurev-immunol-051116-052206] [Citation(s) in RCA: 136] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Peter J.M. Openshaw
- Respiratory Infections, National Heart and Lung Institute, Imperial College London, London W2 1PG, United Kingdom
| | - Chris Chiu
- Respiratory Infections, National Heart and Lung Institute, Imperial College London, London W2 1PG, United Kingdom
| | - Fiona J. Culley
- Respiratory Infections, National Heart and Lung Institute, Imperial College London, London W2 1PG, United Kingdom
| | - Cecilia Johansson
- Respiratory Infections, National Heart and Lung Institute, Imperial College London, London W2 1PG, United Kingdom
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168
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Shook BC, Lin K. Recent Advances in Developing Antiviral Therapies for Respiratory Syncytial Virus. Top Curr Chem (Cham) 2017; 375:40. [DOI: 10.1007/s41061-017-0129-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 03/01/2017] [Indexed: 01/23/2023]
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169
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Drug candidates and model systems in respiratory syncytial virus antiviral drug discovery. Biochem Pharmacol 2017; 127:1-12. [DOI: 10.1016/j.bcp.2016.09.014] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 09/16/2016] [Indexed: 12/11/2022]
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170
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Monoclonal Antibody against G Glycoprotein Increases Respiratory Syncytial Virus Clearance In Vivo and Prevents Vaccine-Enhanced Diseases. PLoS One 2017; 12:e0169139. [PMID: 28076422 PMCID: PMC5226777 DOI: 10.1371/journal.pone.0169139] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 12/12/2016] [Indexed: 01/13/2023] Open
Abstract
Respiratory syncytial virus (RSV) is a common cause of lower respiratory tract illness in infants, young children, and the elderly. The G glycoprotein plays a role in host cell attachment and also modulates the host immune response, thereby inducing disease pathogenesis. We generated two monoclonal antibodies (mAbs; 5H6 and 3A5) against G protein core fragment (Gcf), which consisted of amino acid residues 131 to 230 from RSV A2 G protein. Epitope mapping study revealed that 5H6 specifically binds to the G/164-176 peptide that includes conserved sequences shared by both RSV A and B subtypes, and 3A5 binds to the G/190-204 peptide. Studies with mutant Gcf proteins in which cysteine residues were substituted with alanine revealed that 5H6 requires four cysteines for binding and 3A5 binds to Gcf variants with alanine substitutions better than wild-type. To determine if these mAbs reduce pulmonary viral infection, BALB/c mice were administered mAb and subsequently challenged with RSV. On day 4 post-infection, lung viral titers were reduced by up to 93% with the 5H6 injection and 90% with the 3A5 injection, indicating that prophylactic injection of these mAbs contributes to RSV clearance in vivo. Importantly, 5H6 injection reduced vaccine-enhanced diseases. Overall, our results suggest that this novel anti-G mAb could be used as a prophylactic regimen against RSV diseases.
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171
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Abstract
Respiratory syncytial virus (RSV) is the single most important cause of severe respiratory infection in very young infants. It has also been recently recognized as a significant cause of severe illness in elderly adults, those with underlying cardiopulmonary disease, and the immunocompromised. RSV is suspected of playing a major role in the development of asthma. Prophylaxis in high-risk infants using a monoclonal antibody is the only effective specific therapy available but recent breakthroughs in vaccine design and antiviral drugs offer the promise of effective prophylactic and therapeutic agents against RSV.
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Affiliation(s)
- Edward E Walsh
- Infectious Diseases Division, Department of Medicine, Rochester General Hospital, University of Rochester School of Medicine, 1425 Portland Avenue, Rochester, NY 14621, USA.
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172
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Abstract
Respiratory syncytial virus (RSV) is a common cause of upper respiratory tract infection in children and adults. However, infection with this virus sometimes leads to severe lower respiratory disease and is the major cause of infant hospitalisations in the developed world. Several risk factors such as baby prematurity and congenital heart disease are known to predispose towards severe disease but previously healthy, full-term infants can also develop bronchiolitis and viral pneumonia during RSV infection. The causes of severe disease are not fully understood but may include dysregulation of the immune response to the virus, resulting in excessive recruitment and activation of innate and adaptive immune cells that can cause damage. This review highlights recent discoveries on the balancing act of immune-mediated virus clearance versus immunopathology during RSV infection.
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Affiliation(s)
- Cecilia Johansson
- Respiratory Infections Section, St Mary's campus, National Heart and Lung Institute, Imperial College London, London, W2 1PG, UK
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173
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Mehedi M, McCarty T, Martin SE, Le Nouën C, Buehler E, Chen YC, Smelkinson M, Ganesan S, Fischer ER, Brock LG, Liang B, Munir S, Collins PL, Buchholz UJ. Actin-Related Protein 2 (ARP2) and Virus-Induced Filopodia Facilitate Human Respiratory Syncytial Virus Spread. PLoS Pathog 2016; 12:e1006062. [PMID: 27926942 PMCID: PMC5142808 DOI: 10.1371/journal.ppat.1006062] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 11/14/2016] [Indexed: 11/19/2022] Open
Abstract
Human respiratory syncytial virus (RSV) is an enveloped RNA virus that is the most important viral cause of acute pediatric lower respiratory tract illness worldwide, and lacks a vaccine or effective antiviral drug. The involvement of host factors in the RSV replicative cycle remains poorly characterized. A genome-wide siRNA screen in human lung epithelial A549 cells identified actin-related protein 2 (ARP2) as a host factor involved in RSV infection. ARP2 knockdown did not reduce RSV entry, and did not markedly reduce gene expression during the first 24 hr of infection, but decreased viral gene expression thereafter, an effect that appeared to be due to inhibition of viral spread to neighboring cells. Consistent with reduced spread, there was a 10-fold reduction in the release of infectious progeny virions in ARP2-depleted cells at 72 hr post-infection. In addition, we found that RSV infection induced filopodia formation and increased cell motility in A549 cells and that this phenotype was ARP2 dependent. Filopodia appeared to shuttle RSV to nearby uninfected cells, facilitating virus spread. Expression of the RSV F protein alone from a plasmid or heterologous viral vector in A549 cells induced filopodia, indicating a new role for the RSV F protein, driving filopodia induction and virus spread. Thus, this study identified roles for ARP2 and filopodia in RSV-induced cell motility, RSV production, and RSV cell-to-cell spread. RSV is the most common viral cause of severe acute pediatric lower respiratory tract illness, including pneumonia and bronchiolitis, in young children worldwide. In a genome-wide siRNA screen in human lung epithelial A549 cells infected with RSV expressing green fluorescent protein (RSV-GFP), we identified ARP2 as a cellular factor with a role in the RSV replicative cycle. ARP2 is part of the actin-related protein 2/3 (ARP2/3) complex, which contributes to cell shape and motility through its role in actin polymerization. ARP2 depletion reduced the production and spread of RSV in human lung epithelial cell cultures, with the most noticeable effects at late time points after RSV infection. RSV infection induced the formation of slender actin-rich cell protrusions, called filopodia and increased cell motility. Filopodia formation and cell motility were inhibited by ARP2 knockdown. The filopodia appeared to shuttle RSV to neighboring cells, facilitating virus spread. Thus, RSV uses two previously unrecognized ARP2 dependent features to facilitate viral spread, namely cell motility and filopodia formation.
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Affiliation(s)
- Masfique Mehedi
- RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
| | - Thomas McCarty
- RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Scott E. Martin
- Division of Pre-Clinical Innovation, National Center for Advancing Translational Sciences, Rockville, Maryland, United States of America
| | - Cyril Le Nouën
- RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Eugen Buehler
- Division of Pre-Clinical Innovation, National Center for Advancing Translational Sciences, Rockville, Maryland, United States of America
| | - Yu-Chi Chen
- Division of Pre-Clinical Innovation, National Center for Advancing Translational Sciences, Rockville, Maryland, United States of America
| | - Margery Smelkinson
- Biological Imaging Section, Research Technologies Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Sundar Ganesan
- Biological Imaging Section, Research Technologies Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Elizabeth R. Fischer
- Microscopy Unit, Rocky Mountain Laboratories, Research Technologies Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Linda G. Brock
- RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Bo Liang
- RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Shirin Munir
- RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Peter L. Collins
- RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Ursula J. Buchholz
- RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
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174
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Majumdar T, Dhar J, Patel S, Kondratov R, Barik S. Circadian transcription factor BMAL1 regulates innate immunity against select RNA viruses. Innate Immun 2016; 23:147-154. [PMID: 27913791 DOI: 10.1177/1753425916681075] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
BMAL1 (brain and muscle ARNT-like protein 1, also known as MOP3 or ARNT3) belongs to the family of the basic helix-loop-helix (bHLH)-PAS domain-containing transcription factors, and is a key component of the molecular oscillator that generates circadian rhythms. Here, we report that BMAL1-deficient cells are significantly more susceptible to infection by two major respiratory viruses of the Paramyxoviridae family, namely RSV and PIV3. Embryonic fibroblasts from Bmal1-/- mice produced nearly 10-fold more progeny virus than their wild type controls. These results were supported by animal studies whereby pulmonary infection of RSV produced a more severe disease and morbidity in Bmal1-/-mice. These results show that BMAL1 can regulate cellular innate immunity against specific RNA viruses.
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Affiliation(s)
- Tanmay Majumdar
- Department of Biological, Geological and Environmental Sciences, and Center for Gene Regulation in Health and Disease, Cleveland State University, Cleveland, OH, USA
| | - Jayeeta Dhar
- Department of Biological, Geological and Environmental Sciences, and Center for Gene Regulation in Health and Disease, Cleveland State University, Cleveland, OH, USA
| | - Sonal Patel
- Department of Biological, Geological and Environmental Sciences, and Center for Gene Regulation in Health and Disease, Cleveland State University, Cleveland, OH, USA
| | - Roman Kondratov
- Department of Biological, Geological and Environmental Sciences, and Center for Gene Regulation in Health and Disease, Cleveland State University, Cleveland, OH, USA
| | - Sailen Barik
- Department of Biological, Geological and Environmental Sciences, and Center for Gene Regulation in Health and Disease, Cleveland State University, Cleveland, OH, USA
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175
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Mejias A, Garcia-Maurino C, Rodriguez-Fernandez R, Peeples ME, Ramilo O. Development and clinical applications of novel antibodies for prevention and treatment of respiratory syncytial virus infection. Vaccine 2016; 35:496-502. [PMID: 27692523 DOI: 10.1016/j.vaccine.2016.09.026] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 09/04/2016] [Accepted: 09/15/2016] [Indexed: 10/20/2022]
Abstract
Respiratory syncytial virus (RSV) remains a significant cause of morbidity and mortality in infants and young children, immunocompromised patients and the elderly. Despite the high disease burden, an effective and safe vaccine is lacking, although several candidates are currently in development. Current treatment for RSV infection remains largely supportive and RSV-specific options for prophylaxis are limited to palivizumab. In the past few years, novel therapeutic options including nanobodies, polyclonal and monoclonal antibodies have emerged and there are several products in preclinical and Phase-I, -II or -III clinical trials. The major target for antiviral drug development is the surface fusion (F) glycoprotein, which is crucial for the infectivity and pathogenesis of the virus. Solving the structures of the two conformations of the RSV F protein, the prefusion and postfusion forms, has revolutionized RSV research. It is now known that prefusion F is highly superior in inducing neutralizing antibodies. In this section we will review the stages of development and availability of different antibodies directed against RSV for the prevention and also for treatment of acute RSV infections. Some of these newer anti-RSV agents have shown enhanced potency, are being explored through alternative routes of administration, have improved pharmacokinetic profiles with an extended half-life, and may reduce design and manufacturing costs. Management strategies will require targeting not only high-risk populations (including adults or immunocompromised patients), but also previously healthy children who, in fact, represent the majority of children hospitalized with RSV infection. Following treated patients longitudinally is essential for determining the impact of these strategies on the acute disease as well as their possible long-term benefits on lung morbidity.
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Affiliation(s)
- Asuncion Mejias
- Center for Vaccines and Immunity, The Research Institute at Nationwide Children's Hospital, Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH, USA.
| | - Cristina Garcia-Maurino
- Center for Vaccines and Immunity, The Research Institute at Nationwide Children's Hospital, Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Rosa Rodriguez-Fernandez
- Center for Vaccines and Immunity, The Research Institute at Nationwide Children's Hospital, Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH, USA; Department of Pediatrics, Hospital Infantil Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain
| | - Mark E Peeples
- Center for Vaccines and Immunity, The Research Institute at Nationwide Children's Hospital, Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Octavio Ramilo
- Center for Vaccines and Immunity, The Research Institute at Nationwide Children's Hospital, Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH, USA.
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176
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Structural, antigenic and immunogenic features of respiratory syncytial virus glycoproteins relevant for vaccine development. Vaccine 2016; 35:461-468. [PMID: 27692522 DOI: 10.1016/j.vaccine.2016.09.045] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 09/22/2016] [Indexed: 11/22/2022]
Abstract
Extraordinary progress in the structure and immunobiology of the human respiratory syncytial virus glycoproteins has been accomplished during the last few years. Determination of the fusion (F) glycoprotein structure folded in either the prefusion or the postfusion conformation was an inspiring breakthrough not only to understand the structural changes associated with the membrane fusion process but additionally to appreciate the antigenic intricacies of the F protein. Furthermore, these developments have opened new avenues for structure-based designs of promising hRSV vaccine candidates. Finally, recent advances in our knowledge of the attachment (G) glycoprotein and its interaction with cell-surface receptors have revitalized interest in this molecule as a vaccine, as well as its role in hRSV immunobiology.
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177
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Hua Y, Jiao YY, Ma Y, Peng XL, Fu YH, Zheng YP, Hong T, He JS. DNA vaccine encoding central conserved region of G protein induces Th1 predominant immune response and protection from RSV infection in mice. Immunol Lett 2016; 179:95-101. [PMID: 27688078 DOI: 10.1016/j.imlet.2016.09.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 09/15/2016] [Accepted: 09/25/2016] [Indexed: 12/21/2022]
Abstract
Human respiratory syncytial virus (RSV) can cause serious infection in the lower respiratory tract, especially in infants, young children, the elderly and the immunocompromised population worldwide. Previous study demonstrated the polypeptide (amino acids 148-198) of RSV attachment (G) glycoprotein, corresponding to the central conserved region and encompassing CX3C chemokine motif, could induce antibodies and protection from RSV challenge in mice [1,2]. In this study, we evaluated the immune efficacy of the recombinant DNA vaccine of pVAX1/3G148-198 encoding RSV G protein polypeptide. RSV specific serum IgG antibodies with neutralizing activity were stimulated following prime-boost immunization of pVAX1/3G148-198 intramuscularly, and the ratio of IgG2a/IgG1 was 4.93, indicating a Th1 biased immune response. After challenged intranasally with RSV Long, the vaccinated mice showed both decreased lung RSV titers, pulmonary inflammation and body weight loss. The results suggest that pVAX1/3G148-198 DNA vaccine may be an effective RSV vaccine candidate, and deserves further exploration.
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Affiliation(s)
- Ying Hua
- College of Life Sciences & Bioengineering, Beijing Jiaotong University, 3 Shangyuan Cun, Haidian District, Beijing, 100044, China
| | - Yue-Ying Jiao
- College of Life Sciences & Bioengineering, Beijing Jiaotong University, 3 Shangyuan Cun, Haidian District, Beijing, 100044, China
| | - Yao Ma
- College of Life Sciences & Bioengineering, Beijing Jiaotong University, 3 Shangyuan Cun, Haidian District, Beijing, 100044, China
| | - Xiang-Lei Peng
- College of Life Sciences & Bioengineering, Beijing Jiaotong University, 3 Shangyuan Cun, Haidian District, Beijing, 100044, China
| | - Yuan-Hui Fu
- College of Life Sciences & Bioengineering, Beijing Jiaotong University, 3 Shangyuan Cun, Haidian District, Beijing, 100044, China
| | - Yan-Peng Zheng
- College of Life Sciences & Bioengineering, Beijing Jiaotong University, 3 Shangyuan Cun, Haidian District, Beijing, 100044, China
| | - Tao Hong
- College of Life Sciences & Bioengineering, Beijing Jiaotong University, 3 Shangyuan Cun, Haidian District, Beijing, 100044, China
| | - Jin-Sheng He
- College of Life Sciences & Bioengineering, Beijing Jiaotong University, 3 Shangyuan Cun, Haidian District, Beijing, 100044, China.
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Optimal activation of Fc-mediated effector functions by influenza virus hemagglutinin antibodies requires two points of contact. Proc Natl Acad Sci U S A 2016; 113:E5944-E5951. [PMID: 27647907 DOI: 10.1073/pnas.1613225113] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Influenza virus strain-specific monoclonal antibodies (mAbs) provide protection independent of Fc gamma receptor (FcγR) engagement. In contrast, optimal in vivo protection achieved by broadly reactive mAbs requires Fc-FcγR engagement. Most strain-specific mAbs target the head domain of the viral hemagglutinin (HA), whereas broadly reactive mAbs typically recognize epitopes within the HA stalk. This observation has led to questions regarding the mechanism regulating the activation of Fc-dependent effector functions by broadly reactive antibodies. To dissect the molecular mechanism responsible for this dichotomy, we inserted the FLAG epitope into discrete locations on HAs. By characterizing the interactions of several FLAG-tagged HAs with a FLAG-specific antibody, we show that in addition to Fc-FcγR engagement mediated by the FLAG-specific antibody, a second intermolecular bridge between the receptor-binding region of the HA and sialic acid on effector cells is required for optimal activation. Inhibition of this second molecular bridge, through the use of an F(ab')2 or the mutation of the sialic acid-binding site, renders the Fc-FcγR interaction unable to optimally activate effector cells. Our findings indicate that broadly reactive mAbs require two molecular contacts to possibly stabilize the immunologic synapse and potently induce antibody-dependent cell-mediated antiviral responses: (i) the interaction between the Fc of a mAb bound to HA with the FcγR of the effector cell and (ii) the interaction between the HA and its sialic acid receptor on the effector cell. This concept might be broadly applicable for protective antibody responses to viral pathogens that have suitable receptors on effector cells.
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179
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Fearns R, Deval J. New antiviral approaches for respiratory syncytial virus and other mononegaviruses: Inhibiting the RNA polymerase. Antiviral Res 2016; 134:63-76. [PMID: 27575793 DOI: 10.1016/j.antiviral.2016.08.006] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 07/27/2016] [Accepted: 08/07/2016] [Indexed: 11/16/2022]
Abstract
Worldwide, respiratory syncytial virus (RSV) causes severe disease in infants, the elderly, and immunocompromised people. No vaccine or effective antiviral treatment is available. RSV is a member of the non-segmented, negative-strand (NNS) group of RNA viruses and relies on its RNA-dependent RNA polymerase to transcribe and replicate its genome. Because of its essential nature and unique properties, the RSV polymerase has proven to be a good target for antiviral drugs, with one compound, ALS-8176, having already achieved clinical proof-of-concept efficacy in a human challenge study. In this article, we first provide an overview of the role of the RSV polymerase in viral mRNA transcription and genome replication. We then review past and current approaches to inhibiting the RSV polymerase, including use of nucleoside analogs and non-nucleoside inhibitors. Finally, we consider polymerase inhibitors that hold promise for treating infections with other NNS RNA viruses, including measles and Ebola.
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Affiliation(s)
- Rachel Fearns
- Department of Microbiology, Boston University School of Medicine, Boston, MA, USA.
| | - Jerome Deval
- Alios BioPharma, Inc., Part of the Janssen Pharmaceutical Companies, South San Francisco, CA, USA.
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180
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Characterization of Epitope-Specific Anti-Respiratory Syncytial Virus (Anti-RSV) Antibody Responses after Natural Infection and after Vaccination with Formalin-Inactivated RSV. J Virol 2016; 90:5965-5977. [PMID: 27099320 DOI: 10.1128/jvi.00235-16] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 04/12/2016] [Indexed: 12/11/2022] Open
Abstract
UNLABELLED Antibodies against the fusion (F) protein of respiratory syncytial virus (RSV) play an important role in the protective immune response to this important respiratory virus. Little is known, however, about antibody levels against multiple F-specific epitopes induced by infection or after vaccination against RSV, while this is important to guide the evaluation of (novel) vaccines. In this study, we analyzed antibody levels against RSV proteins and F-specific epitopes in human sera and in sera of vaccinated and experimentally infected cotton rats and the correlation thereof with virus neutralization. Analysis of human sera revealed substantial diversity in antibody levels against F-, G (attachment)-, and F-specific epitopes between individuals. The highest correlation with virus neutralization was observed for antibodies recognizing prefusion-specific antigenic site Ø. Nevertheless, our results indicate that high levels of antibodies targeting other parts of the F protein can also mediate a potent antiviral antibody response. In agreement, sera of experimentally infected cotton rats contained high neutralizing activity despite lacking antigenic site Ø-specific antibodies. Strikingly, vaccination with formalin-inactivated RSV (FI-RSV) exclusively resulted in the induction of poorly neutralizing antibodies against postfusion-specific antigenic site I, although antigenic sites I, II, and IV were efficiently displayed in FI-RSV. The apparent immunodominance of antigenic site I in FI-RSV likely explains the low levels of neutralizing antibodies upon vaccination and challenge and may play a role in the vaccination-induced enhancement of disease observed with such preparations. IMPORTANCE RSV is an importance cause of hospitalization of infants. The development of a vaccine against RSV has been hampered by the disastrous results obtained with FI-RSV vaccine preparations in the 1960s that resulted in vaccination-induced enhancement of disease. To get a better understanding of the antibody repertoire induced after infection or after vaccination against RSV, we investigated antibody levels against fusion (F) protein, attachment (G) protein, and F-specific epitopes in human and animal sera. The results indicate the importance of prefusion-specific antigenic site Ø antibodies as well as of antibodies targeting other epitopes in virus neutralization. However, vaccination of cotton rats with FI-RSV specifically resulted in the induction of weakly neutralizing, antigenic site I-specific antibodies, which may play a role in the enhancement of disease observed after vaccination with such preparations.
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181
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Graham BS. Vaccines against respiratory syncytial virus: The time has finally come. Vaccine 2016; 34:3535-41. [PMID: 27182820 DOI: 10.1016/j.vaccine.2016.04.083] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Revised: 04/11/2016] [Accepted: 04/15/2016] [Indexed: 11/27/2022]
Abstract
Respiratory syncytial virus causes a significant public health burden, particularly in very young infants and the frail elderly. The legacy of enhanced RSV disease (ERD) from a whole formalin-inactivated RSV vaccine, and the complex biology of the virus and the neonate have delayed the development of effective vaccines. However, new insights into factors associated with ERD and breakthroughs in understanding the antigenic structure of the fusion (F) glycoprotein have increased optimism that vaccine development is possible. This has led to investment of time and resources by industry, regulatory authorities, governments, and nonprofit organizations to develop the infrastructure needed to make the advanced clinical development of RSV vaccine candidates a reality.
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Affiliation(s)
- Barney S Graham
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States.
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182
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Currier MG, Lee S, Stobart CC, Hotard AL, Villenave R, Meng J, Pretto CD, Shields MD, Nguyen MT, Todd SO, Chi MH, Hammonds J, Krumm SA, Spearman P, Plemper RK, Sakamoto K, Peebles RS, Power UF, Moore ML. EGFR Interacts with the Fusion Protein of Respiratory Syncytial Virus Strain 2-20 and Mediates Infection and Mucin Expression. PLoS Pathog 2016; 12:e1005622. [PMID: 27152417 PMCID: PMC4859522 DOI: 10.1371/journal.ppat.1005622] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 04/19/2016] [Indexed: 11/19/2022] Open
Abstract
Respiratory syncytial virus (RSV) is the major cause of viral lower respiratory tract illness in children. In contrast to the RSV prototypic strain A2, clinical isolate RSV 2–20 induces airway mucin expression in mice, a clinically relevant phenotype dependent on the fusion (F) protein of the RSV strain. Epidermal growth factor receptor (EGFR) plays a role in airway mucin expression in other systems; therefore, we hypothesized that the RSV 2–20 F protein stimulates EGFR signaling. Infection of cells with chimeric strains RSV A2-2-20F and A2-2-20GF or over-expression of 2–20 F protein resulted in greater phosphorylation of EGFR than infection with RSV A2 or over-expression of A2 F, respectively. Chemical inhibition of EGFR signaling or knockdown of EGFR resulted in diminished infectivity of RSV A2-2-20F but not RSV A2. Over-expression of EGFR enhanced the fusion activity of 2–20 F protein in trans. EGFR co-immunoprecipitated most efficiently with RSV F proteins derived from “mucogenic” strains. RSV 2–20 F and EGFR co-localized in H292 cells, and A2-2-20GF-induced MUC5AC expression was ablated by EGFR inhibitors in these cells. Treatment of BALB/c mice with the EGFR inhibitor erlotinib significantly reduced the amount of RSV A2-2-20F-induced airway mucin expression. Our results demonstrate that RSV F interacts with EGFR in a strain-specific manner, EGFR is a co-factor for infection, and EGFR plays a role in RSV-induced mucin expression, suggesting EGFR is a potential target for RSV disease. Respiratory syncytial virus (RSV) is responsible for severe lower respiratory disease in infants and young children. Overabundant airway mucus contributes to airway obstruction in RSV bronchiolitis, and a better understanding of RSV pathogenesis may contribute to needed therapies and vaccines. We reported previously that RSV clinical isolate strain 2–20 induces more airway mucin expression in mice than prototypic RSV strains and that the 2–20 fusion (F) protein mediates mucin induction. Epidermal growth factor receptor (EGFR) has been shown to play a role in lung mucin expression. We identified a functional interaction between 2–20 F and EGFR, in that 2–20 F expression activated EGFR and, reciprocally, EGFR expression increased 2–20 F fusion activity. RSV F and EGFR co-localized in infected cells. EGFR co-immunoprecipitated with RSV F protein from various RSV strains, and the strength of this in vitro interaction correlated with strain-specific airway pathogenicity in mice. EGFR inhibition abrogated 2–20 F-mediated infection in vitro and mucin expression induction in vivo. These data identify EGFR as a novel strain-specific co-factor of RSV infection and suggest EGFR may be a target for ameliorating RSV disease.
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Affiliation(s)
- Michael G. Currier
- Department of Pediatrics, Emory University, Atlanta, Georgia, United States of America
- Children’s Healthcare of Atlanta, Atlanta, Georgia, United States of America
| | - Sujin Lee
- Department of Pediatrics, Emory University, Atlanta, Georgia, United States of America
- Children’s Healthcare of Atlanta, Atlanta, Georgia, United States of America
| | - Christopher C. Stobart
- Department of Pediatrics, Emory University, Atlanta, Georgia, United States of America
- Children’s Healthcare of Atlanta, Atlanta, Georgia, United States of America
| | - Anne L. Hotard
- Department of Pediatrics, Emory University, Atlanta, Georgia, United States of America
- Children’s Healthcare of Atlanta, Atlanta, Georgia, United States of America
| | - Remi Villenave
- Centre for Infection and Immunity, School of Medicine, Dentistry and Biomedical Science, Queens University Belfast, Belfast, Northern Ireland
| | - Jia Meng
- Department of Pediatrics, Emory University, Atlanta, Georgia, United States of America
- Children’s Healthcare of Atlanta, Atlanta, Georgia, United States of America
| | - Carla D. Pretto
- Department of Pediatrics, Emory University, Atlanta, Georgia, United States of America
- Children’s Healthcare of Atlanta, Atlanta, Georgia, United States of America
| | - Michael D. Shields
- Centre for Infection and Immunity, School of Medicine, Dentistry and Biomedical Science, Queens University Belfast, Belfast, Northern Ireland
- The Royal Belfast Hospital for Sick Children, Belfast, Northern Ireland
| | - Minh Trang Nguyen
- Department of Pediatrics, Emory University, Atlanta, Georgia, United States of America
- Children’s Healthcare of Atlanta, Atlanta, Georgia, United States of America
| | - Sean O. Todd
- Department of Pediatrics, Emory University, Atlanta, Georgia, United States of America
- Children’s Healthcare of Atlanta, Atlanta, Georgia, United States of America
| | - Michael H. Chi
- Division of Allergy, Pulmonary, and Critical Care Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Jason Hammonds
- Department of Pediatrics, Emory University, Atlanta, Georgia, United States of America
- Children’s Healthcare of Atlanta, Atlanta, Georgia, United States of America
| | - Stefanie A. Krumm
- Institute for Biomedical Sciences, Georgia State University, Atlanta, Georgia, United States of America
| | - Paul Spearman
- Department of Pediatrics, Emory University, Atlanta, Georgia, United States of America
- Children’s Healthcare of Atlanta, Atlanta, Georgia, United States of America
| | - Richard K. Plemper
- Institute for Biomedical Sciences, Georgia State University, Atlanta, Georgia, United States of America
| | - Kaori Sakamoto
- Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, Georgia, United States of America
| | - R. Stokes Peebles
- Division of Allergy, Pulmonary, and Critical Care Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Ultan F. Power
- Centre for Infection and Immunity, School of Medicine, Dentistry and Biomedical Science, Queens University Belfast, Belfast, Northern Ireland
| | - Martin L. Moore
- Department of Pediatrics, Emory University, Atlanta, Georgia, United States of America
- Children’s Healthcare of Atlanta, Atlanta, Georgia, United States of America
- * E-mail:
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183
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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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184
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Preventing Cleavage of the Respiratory Syncytial Virus Attachment Protein in Vero Cells Rescues the Infectivity of Progeny Virus for Primary Human Airway Cultures. J Virol 2015; 90:1311-20. [PMID: 26581976 DOI: 10.1128/jvi.02351-15] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Accepted: 11/05/2015] [Indexed: 01/20/2023] Open
Abstract
UNLABELLED All live attenuated respiratory syncytial virus (RSV) vaccines that have advanced to clinical trials have been produced in Vero cells. The attachment (G) glycoprotein in virions produced in these cells is smaller than that produced in other immortalized cells due to cleavage. These virions are 5-fold less infectious for primary well-differentiated human airway epithelial (HAE) cell cultures. Because HAE cells are isolated directly from human airways, Vero cell-grown vaccine virus would very likely be similarly inefficient at initiating infection of the nasal epithelium following vaccination, and therefore, a larger inoculum would be required for effective vaccination. We hypothesized that Vero cell-derived virus containing an intact G protein would be more infectious for HAE cell cultures. Using protease inhibitors with increasing specificity, we identified cathepsin L to be the protease responsible for cleavage. Our evidence suggests that cleavage occurs in the late endosome or lysosome during endocytic recycling. Cathepsin L activity was 100-fold greater in Vero cells than in HeLa cells. In addition, cathepsin L was able to cleave the G protein in Vero cell-grown virions but not in HeLa cell-grown virions, suggesting a difference in G-protein posttranslational modification in the two cell lines. We identified by mutagenesis amino acids important for cleavage, and these amino acids included a likely cathepsin L cleavage site. Virus containing a modified, noncleavable G protein produced in Vero cells was 5-fold more infectious for HAE cells in culture, confirming our hypothesis and indicating the value of including such a mutation in future live attenuated RSV vaccines. IMPORTANCE Worldwide, RSV is the second leading infectious cause of infant death, but no vaccine is available. Experimental live attenuated RSV vaccines are grown in Vero cells, but during production the virion attachment (G) glycoprotein is cleaved. Virions containing a cleaved G protein are less infectious for primary airway epithelial cells, the natural RSV target. In the study described here we identified the protease responsible, located the cleavage site, and demonstrated that cleavage likely occurs during endocytic recycling. Moreover, we showed that the infectivity of Vero cell-derived virus for primary airway epithelial cells is increased 5-fold if the virus contains a mutation in the G protein that prevents cleavage. The blocking of cleavage should improve RSV vaccine yield, consequently reducing production costs. Posttranslational cleavage of the fusion glycoprotein of many viruses plays an essential role in activation; however, cleavage of the RSV G protein is a novel example of a detrimental effect of cleavage on virus infectivity.
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