Neutralizing epitope of the Fusion Protein of Respiratory Syncytial Virus Embedded in the HA Molecule of LAIV Virus is not Sufficient to Prevent RS Virus Pulmonary Replication but Ameliorates Lung Pathology following RSV Infection in Mice

Aims: To develop experimental bivalent vaccines against influenza and RSV using a cold-adapted LAIV backbone. Background: Respiratory syncytial virus (RSV) is a causative agent of bronchiolitis and pneumonia in young children, elderly and immunocompromised adults. No vaccine against RSV has been licensed to date for various reasons. One of the promising platforms for designing RSV vaccine is the use of live attenuated influenza vaccine (LAIV) viruses to deliver RSV epitopes to the respiratory mucosa. Objective: To generate recombinant LAIV viruses encoding a neutralizing epitope of the RSV fusion protein and assess their protective potential against both influenza and RSV infections in a mouse model. Methods: Reverse genetics methods were used to rescue recombinant LAIV+HA/RSV viruses expressing chimeric hemagglutinins encoding the RSV-F epitope at its N-terminus using two different flexible linkers. BALB/c mice were intranasally immunized with two doses of the recombinant viruses and then challenged with the influenza virus or RSV. The LAIV viral vector and formalin-inactivated RSV (FI-RSV) were included as control vaccines. Protection was assessed by the reduction of virus pulmonary titers. In addition, RSV-induced lung pathology was evaluated by histopathology studies. Results: Two rescued chimeric LAIV+HA/RSV viruses were identical to the LAIV vector in terms of replication capacity in vitro and in vivo. The RSV-F neutralizing epitope was successfully expressed only if inserted into the HA molecule via G-linker, but not A-linker. Both chimeric viruses induced high influenza-specific antibody levels and fully protected mice against a lethal influenza challenge virus. However, they induced weak anti-RSV antibody responses which did not prevent RS virus replication upon challenge, and only LAIV-HA+G-RSV variant protected mice against RSV-induced lung pathology. Conclusion: Although the designed LAIV-RSV chimeric viruses were unable to neutralize the RS virus pulmonary replication, the LAIV-HA+G-RSV reduced RSV-induced lung pathology and can be considered a promising bivalent vaccine against influenza and RSV infections and warrants its further development.

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Evaluation of the Safety and Immune Efficacy of Recombinant Human Respiratory Syncytial Virus Strain Long Live Attenuated Vaccine Candidates

Virologica Sinica ◽

10.1007/s12250-021-00345-3 ◽

2021 ◽

Author(s):

Li-Nan Wang ◽

Xiang-Lei Peng ◽

Min Xu ◽

Yuan-Bo Zheng ◽

Yue-Ying Jiao ◽

...

Keyword(s):

Respiratory Syncytial Virus ◽

Gene Deletion ◽

Human Respiratory Syncytial Virus ◽

Temperature Sensitive ◽

T7 Promoter ◽

Vaccine Candidates ◽

Rsv Infection ◽

Syncytial Virus

AbstractHuman respiratory syncytial virus (RSV) infection is the leading cause of lower respiratory tract illness (LRTI), and no vaccine against LRTI has proven to be safe and effective in infants. Our study assessed attenuated recombinant RSVs as vaccine candidates to prevent RSV infection in mice. The constructed recombinant plasmids harbored (5′ to 3′) a T7 promoter, hammerhead ribozyme, RSV Long strain antigenomic cDNA with cold-passaged (cp) mutations or cp combined with temperature-sensitive attenuated mutations from the A2 strain (A2cpts) or further combined with SH gene deletion (A2cptsΔSH), HDV ribozyme (δ), and a T7 terminator. These vectors were subsequently co-transfected with four helper plasmids encoding N, P, L, and M2-1 viral proteins into BHK/T7-9 cells, and the recovered viruses were then passaged in Vero cells. The rescued recombinant RSVs (rRSVs) were named rRSV-Long/A2cp, rRSV-Long/A2cpts, and rRSV-Long/A2cptsΔSH, respectively, and stably passaged in vitro, without reversion to wild type (wt) at sites containing introduced mutations or deletion. Although rRSV-Long/A2cpts and rRSV-Long/A2cptsΔSH displayed temperature-sensitive (ts) phenotype in vitro and in vivo, all rRSVs were significantly attenuated in vivo. Furthermore, BALB/c mice immunized with rRSVs produced Th1-biased immune response, resisted wtRSV infection, and were free from enhanced respiratory disease. We showed that the combination of ΔSH with attenuation (att) mutations of cpts contributed to improving att phenotype, efficacy, and gene stability of rRSV. By successfully introducing att mutations and SH gene deletion into the RSV Long parent and producing three rRSV strains, we have laid an important foundation for the development of RSV live attenuated vaccines.

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Inhibitory Effect of Sargassum fusiforme and Its Components on Replication of Respiratory Syncytial Virus In Vitro and In Vivo

Viruses ◽

10.3390/v13040548 ◽

2021 ◽

Vol 13 (4) ◽

pp. 548

Author(s):

Kiramage Chathuranga ◽

Asela Weerawardhana ◽

Niranjan Dodantenna ◽

Lakmal Ranathunga ◽

Won-Kyung Cho ◽

...

Keyword(s):

Respiratory Syncytial Virus ◽

Antiviral Agent ◽

Active Components ◽

Sargassum Fusiforme ◽

Antiviral Effects ◽

Improve Life Expectancy ◽

Rsv Infection ◽

Syncytial Virus

Sargassum fusiforme, a plant used as a medicine and food, is regarded as a marine vegetable and health supplement to improve life expectancy. Here, we demonstrate that S. fusiforme extract (SFE) has antiviral effects against respiratory syncytial virus (RSV) in vitro and in vivo mouse model. Treatment of HEp2 cells with a non-cytotoxic concentration of SFE significantly reduced RSV replication, RSV-induced cell death, RSV gene transcription, RSV protein synthesis, and syncytium formation. Moreover, oral inoculation of SFE significantly improved RSV clearance from the lungs of BALB/c mice. Interestingly, the phenolic compounds eicosane, docosane, and tetracosane were identified as active components of SFE. Treatment with a non-cytotoxic concentration of these three components elicited similar antiviral effects against RSV infection as SFE in vitro. Together, these results suggest that SFE and its potential components are a promising natural antiviral agent candidate against RSV infection.

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In Vitro and In Vivo Fitness of Respiratory Syncytial Virus Monoclonal Antibody Escape Mutants

Journal of Virology ◽

10.1128/jvi.01387-06 ◽

2006 ◽

Vol 80 (23) ◽

pp. 11651-11657 ◽

Cited By ~ 20

Author(s):

Xiaodong Zhao ◽

Enmei Liu ◽

Fu-Ping Chen ◽

Wayne M. Sullender

Keyword(s):

Cell Culture ◽

Monoclonal Antibody ◽

Respiratory Syncytial Virus ◽

Viral Population ◽

Nucleotide Substitutions ◽

Cotton Rats ◽

Syncytial Virus ◽

In Vivo Growth

ABSTRACT Respiratory syncytial virus (RSV) is the only infectious disease for which a monoclonal antibody (MAb) is used in humans. Palivizumab (PZ) is a humanized murine MAb to the F protein of RSV. PZ-resistant viruses appear after in vitro and in vivo growth of RSV in the presence of PZ. Fitness for replication could be a determinant of the likelihood of dissemination of resistant viruses. We assessed the fitness of two PZ-resistant viruses (F212 and MP4). F212 grew less well in cell culture than the parent A2 virus and was predicted to be less fit than A2. Equal amounts of F212 and A2 were mixed and passaged in cell culture. F212 disappeared from the viral population, indicating it was less fit than the A2 virus. The MP4 virus grew as well as A2 in culture and in cotton rats. A2/MP4 virus input ratios of 1:1, 10:1, 100:1, and 1,000:1 were compared in competitive replication. For all input ratios except 1,000:1, the MP4 virus became dominant, supplanting the A2 virus. The MP4 virus also dominated the A2 virus during growth in cotton rats. Thus, the mutant MP4 virus was more fit than A2 virus in both in vitro and in vivo competitive replication. Whether this fitness difference was due to the identified nucleotide substitutions in the F gene or to mutations elsewhere in the genome is unknown. Understanding the mechanisms by which mutant virus fitness increased or decreased could prove useful for consideration in attenuated vaccine design efforts.

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Exacerbation of Influenza A Virus Disease Severity by Respiratory Syncytial Virus Co-Infection in a Mouse Model

Viruses ◽

10.3390/v13081630 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1630 ◽

Cited By ~ 1

Author(s):

Junu A. George ◽

Shaikha H. AlShamsi ◽

Maryam H. Alhammadi ◽

Ahmed R. Alsuwaidi

Keyword(s):

T Cells ◽

Respiratory Syncytial Virus ◽

Influenza A Virus ◽

Influenza A ◽

Immune Cell ◽

Virus Disease ◽

Viral Loads ◽

Syncytial Virus

Influenza A virus (IAV) and respiratory syncytial virus (RSV) are leading causes of childhood infections. RSV and influenza are competitive in vitro. In this study, the in vivo effects of RSV and IAV co-infection were investigated. Mice were intranasally inoculated with RSV, with IAV, or with both viruses (RSV+IAV and IAV+RSV) administered sequentially, 24 h apart. On days 3 and 7 post-infection, lung tissues were processed for viral loads and immune cell populations. Lung functions were also evaluated. Mortality was observed only in the IAV+RSV group (50% of mice did not survive beyond 7 days). On day 3, the viral loads in single-infected and co-infected mice were not significantly different. However, on day 7, the IAV titer was much higher in the IAV+RSV group, and the RSV viral load was reduced. CD4 T cells were reduced in all groups on day 7 except in single-infected mice. CD8 T cells were higher in all experimental groups except the RSV-alone group. Increased airway resistance and reduced thoracic compliance were demonstrated in both co-infected groups. This model indicates that, among all the infection types we studied, infection with IAV followed by RSV is associated with the highest IAV viral loads and the most morbidity and mortality.

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Assessing Uncertainty in A2 Respiratory Syncytial Virus Viral Dynamics

Computational and Mathematical Methods in Medicine ◽

10.1155/2015/567589 ◽

2015 ◽

Vol 2015 ◽

pp. 1-9 ◽

Cited By ~ 15

Author(s):

Gilberto González-Parra ◽

Hana M. Dobrovolny

Keyword(s):

Respiratory Syncytial Virus ◽

Human Subjects ◽

Respiratory Illness ◽

The United States ◽

Viral Kinetics ◽

Phase Duration ◽

Syncytial Virus ◽

Parameter Values

Respiratory syncytial virus (RSV) is the most common cause of bronchiolitis and pneumonia in children younger than 1 year of age in the United States. Moreover, RSV is being recognized more often as a significant cause of respiratory illness in older adults. Although RSV has been studied both clinically and in vitro, a quantitative understanding of the infection dynamics is still lacking. In this paper, we study the effect of uncertainty in the main parameters of a viral kinetics model of RSV. We first characterize the RSV replication cycle and extract parameter values by fitting the mathematical model to in vivo data from eight human subjects. We then use Monte Carlo numerical simulations to determine how uncertainty in the parameter values will affect model predictions. We find that uncertainty in the infection rate, eclipse phase duration, and infectious lifespan most affect the predicted dynamics of RSV. This study provides the first estimate of in vivo RSV infection parameters, helping to quantify RSV dynamics. Our assessment of the effect of uncertainty will help guide future experimental design to obtain more precise parameter values.

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Induction of high-mobility group Box-1 in vitro and in vivo by respiratory syncytial virus

Pediatric Research ◽

10.1038/pr.2018.6 ◽

2018 ◽

Vol 83 (5) ◽

pp. 1049-1056 ◽

Cited By ~ 11

Author(s):

Sara Manti ◽

Terri J Harford ◽

Carmelo Salpietro ◽

Fariba Rezaee ◽

Giovanni Piedimonte

Keyword(s):

Respiratory Syncytial Virus ◽

High Mobility ◽

High Mobility Group ◽

Syncytial Virus

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Targeting the Respiratory Syncytial Virus N0-P Complex with Constrained α-Helical Peptides in Cells and Mice

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00717-20 ◽

2020 ◽

Vol 64 (10) ◽

Author(s):

Marie Galloux ◽

Nadège Gsponer ◽

Vanessa Gaillard ◽

Brice Fenner ◽

Thibaut Larcher ◽

...

Keyword(s):

Respiratory Syncytial Virus ◽

Small Molecules ◽

Mechanisms Of Action ◽

Rsv Infection ◽

Macrocyclic Peptides ◽

Escape Mutants ◽

Severe Respiratory Infection ◽

Syncytial Virus

ABSTRACT Respiratory syncytial virus (RSV) is the main cause of severe respiratory infection in young children worldwide, and no therapies have been approved for the treatment of RSV infection. Data from recent clinical trials of fusion or L polymerase inhibitors for the treatment of RSV-infected patients revealed the emergence of escape mutants, highlighting the need for the discovery of inhibitors with novel mechanisms of action. Here we describe stapled peptides derived from the N terminus of the phosphoprotein (P) that act as replication inhibitors. We demonstrate that these peptides inhibit RSV replication in vitro and in vivo by preventing the formation of the N0-P complex. The present strategy provides a novel means of targeting RSV replication with constrained macrocyclic peptides or small molecules and is broadly applicable to other viruses of the Mononegavirales order.

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