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

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.

scholarly journals Genetic Stability of Parainfluenza Virus 5-Vectored Human Respiratory Syncytial Virus Vaccine Candidates after In Vitro and In Vivo Passage

2017 ◽  
Vol 91 (19) ◽  
Author(s):  
Shannon I. Phan ◽  
Carolyn M. Adam ◽  
Zhenhai Chen ◽  
Michael Citron ◽  
Xiaoping Liang ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Genetic Stability ◽  
Human Respiratory Syncytial Virus ◽  
Parainfluenza Virus ◽  
Vaccine Candidates ◽  
Consensus Sequences ◽  
Parainfluenza Virus 5 ◽  
Syncytial Virus

ABSTRACT Human respiratory syncytial virus (RSV) is the leading etiologic agent of lower respiratory tract infections in children, but no licensed vaccine exists. Previously, we developed two parainfluenza virus 5 (PIV5)-based RSV vaccine candidates that protect mice against RSV challenge. PIV5 was engineered to express either the RSV fusion protein (F) or the RSV major attachment glycoprotein (G) between the hemagglutinin-neuraminidase (HN) and RNA-dependent RNA polymerase (L) genes of the PIV5 genome [PIV5-RSV-F (HN-L) and PIV5-RSV-G (HN-L), respectively]. To investigate the stability of the vaccine candidates in vitro, they were passaged in Vero cells at high and low multiplicities of infection (MOIs) for 11 generations and the genome sequences, growth kinetics, and protein expression of the resulting viruses were compared with those of the parent viruses. Sporadic mutations were detected in the consensus sequences of the viruses after high-MOI passages, and mutation rates increased under low-MOI-passage conditions. None of the mutations abolished antigen expression. Increased numbers of mutations correlated with increased growth rates in vitro, indicating that the viruses evolved through the course of serial passages. We also examined the in vivo stability of the vaccine candidates after a single passage in African green monkeys. No mutations were detected in the consensus sequences of viruses collected from the bronchoalveolar lavage (BAL) fluid of the animals. In vivo, mutations in RSV G and PIV5 L were found in individual isolates of PIV5-RSV-G (HN-L), but plaque isolates of PIV5-RSV-F (HN-L) had no mutations. To improve upon the PIV5-RSV-F (HN-L) candidate, additional vaccine candidates were generated in which the gene for RSV F was inserted into earlier positions in the PIV5 genome. These insertions did not negatively impact the sequence stability of the vaccine candidates. The results suggest that the RSV F and G gene insertions are stable in the PIV5 genome. However, the function of the foreign gene insertion may need to be considered when designing PIV5-based vaccines. IMPORTANCE The genetic stability of live viral vaccines is important for safety and efficacy. PIV5 is a promising live viral vector and has been used to develop vaccines. In this work, we examined the genetic stability of a PIV5-based RSV vaccine in vitro and in vivo. We found that insertions of foreign genes, such as the RSV F and G genes, were stably maintained in the PIV5 genome and there was no mutation that abolished the expression of RSV F or G. Interestingly, the function of the inserted gene may have an impact on PIV5 genome stability.

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

Viruses ◽  
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.

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

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.

scholarly journals Mitoxantrone Shows In Vitro, but Not In Vivo Antiviral Activity against Human Respiratory Syncytial Virus

Biomedicines ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1176
Author(s):  
Patricia G. de la Sota ◽  
Elena Lorente ◽  
Laura Notario ◽  
Carmen Mir ◽  
Oscar Zaragoza ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Respiratory Infections ◽  
The Elderly ◽  
Human Respiratory Syncytial Virus ◽  
Mice Model ◽  
Drug Candidates ◽  
Antiviral Activities ◽  
Syncytial Virus

Human respiratory syncytial virus (HRSV) is the most common cause of severe respiratory infections in infants and young children, often leading to hospitalization. In addition, this virus poses a serious health risk in immunocompromised individuals and the elderly. HRSV is also a major nosocomial hazard in healthcare service units for patients of all ages. Therefore, the development of antiviral treatments against HRSV is a global health priority. In this study, mitoxantrone, a synthetic anthraquinone with previously reported in vitro antiprotozoal and antiviral activities, inhibits HRSV replication in vitro, but not in vivo in a mice model. These results have implications for preclinical studies of some drug candidates.

scholarly journals Role of G2-S16 Polyanionic Carbosilane Dendrimer in the Prevention of Respiratory Syncytial Virus Infection In Vitro and In Vivo in Mice

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2141
Author(s):  
Ignacio Rodriguez-Izquierdo ◽  
Rafael Ceña-Diez ◽  
Maria Jesús Serramia ◽  
Rosa Rodriguez-Fernández ◽  
Isidoro Martínez ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Cell Surface ◽  
Host Cells ◽  
Carbosilane Dendrimer ◽  
Rsv Infection ◽  
Host Cell Surface ◽  
Syncytial Virus

The respiratory syncytial virus (RSV) causes respiratory infection and bronchiolitis, requiring hospitalization mainly in infants. The interaction between RSV, envelope glycoproteins G and F, and cell surface heparan sulfate proteoglycans (HSPG) is required for binding and entry into the host cells. A G2-S16 polyanionic carbosilane dendrimer was identified as a possible RSV inhibitor. We speculated that the G2-S16 dendrimer adheres to the host cell-surface HSPG, acts through binding to HS receptors, and prevents further RSV infection. The G2-S16 dendrimer was non-toxic when applied intranasally to Balb/c mice, and interestingly enough, this G2-S16 dendrimer inhibits 85% RSV. Therefore, our G2-S16 dendrimer could be a candidate for developing a new possible therapy against RSV infection.

scholarly journals Oral Efficacy of a Respiratory Syncytial Virus Inhibitor in Rodent Models of Infection

2004 ◽  
Vol 48 (7) ◽  
pp. 2448-2454 ◽  
Author(s):  
Christopher Cianci ◽  
Eugene V. Genovesi ◽  
Lucinda Lamb ◽  
Ivette Medina ◽  
Zheng Yang ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Oral Dose ◽  
Single Amino Acid ◽  
Dose Titration ◽  
In Vivo Efficacy ◽  
Cotton Rat ◽  
Rsv Infection ◽  
Syncytial Virus

ABSTRACT BMS-433771 is a potent inhibitor of respiratory syncytial virus (RSV) replication in vitro. Mechanism of action studies have demonstrated that BMS-433771 halts virus entry through inhibition of F protein-mediated membrane fusion. BMS-433771 also exhibited in vivo efficacy following oral administration in a mouse model of RSV infection (C. Cianci, K. Y. Yu, K. Combrink, N. Sin, B. Pearce, A. Wang, R. Civiello, S. Voss, G. Luo, K. Kadow, E. Genovesi, B. Venables, H. Gulgeze, A. Trehan, J. James, L. Lamb, I. Medina, J. Roach, Z. Yang, L. Zadjura, R. Colonno, J. Clark, N. Meanwell, and M. Krystal, Antimicrob. Agents Chemother. 48:413-422, 2004). In this report, the in vivo efficacy of BMS-433771 against RSV was further examined in the BALB/c mouse and cotton rat host models of infection. By using the Long strain of RSV, prophylactic efficacy via oral dosing was observed in both animal models. A single oral dose, administered 1 h prior to intranasal RSV inoculation, was as effective against infection as a 4-day b.i.d. dosing regimen in which the first oral dose was given 1 h prior to virus inoculation. Results of dose titration experiments suggested that RSV infection was more sensitive to inhibition by BMS-433771 treatment in the BALB/c mouse host than in the cotton rat. This was reflected by the pharmacokinetic and pharmacodynamic analysis of the efficacy data, where the area under the concentration-time curve required to achieve 50% of the maximum response was ∼7.5-fold less for mice than for cotton rats. Inhibition of RSV by BMS-433771 in the mouse is the result of F1-mediated inhibition, as shown by the fact that a virus selected for resistance to BMS-433771 in vitro and containing a single amino acid change in the F1 region was also refractory to treatment in the mouse host. BMS-433771 efficacy against RSV infection was also demonstrated for mice that were chemically immunosuppressed by cyclophosphamide treatment, indicating that compound inhibition of the virus did not require an active host immune response.

scholarly journals A Peptide Mimic of a Protective Epitope of Respiratory Syncytial Virus Selected from a Combinatorial Library Induces Virus-Neutralizing Antibodies and Reduces Viral Load In Vivo

1998 ◽  
Vol 72 (3) ◽  
pp. 2040-2046 ◽  
Author(s):  
Daniel Chargelegue ◽  
Obeid E. Obeid ◽  
Shiou-Chih Hsu ◽  
Michael D. Shaw ◽  
Andrew N. Denbury ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Neutralizing Antibodies ◽  
Solid Phase ◽  
Effective Vaccine ◽  
Peptide Mimic ◽  
Rsv Infection ◽  
Multiple Antigen Peptides ◽  
Syncytial Virus

ABSTRACT Respiratory syncytial virus (RSV) is the most important cause of bronchiolitis and pneumonia in infants and young children worldwide. As yet, there is no effective vaccine against RSV infection, and previous attempts to develop a formalin-inactivated vaccine resulted in exacerbated disease in recipients subsequently exposed to the virus. In the work described here, a combinatorial solid-phase peptide library was screened with a protective monoclonal antibody (MAb 19) to identify peptide mimics (mimotopes) of a conserved and conformationally-determined epitope of RSV fusion (F) protein. Two sequences identified (S1 [HWYISKPQ] and S2 [HWYDAEVL]) reacted specifically with MAb 19 when they were presented as solid-phase peptides. Furthermore, after amino acid substitution analyses, three sequences derived from S1 (S1S [HWSISKPQ], S1K [KWYISKPQ], and S1P [HPYISKPQ]), presented as multiple antigen peptides (MAPs), also showed strong reactivity with MAb 19. The affinity constants of the binding of MAb 19, determined by surface plasmon resonance analyses, were 1.19 × 109 and 4.93 × 109 M−1 for S1 and S1S, respectively. Immunization of BALB/c mice with these mimotopes, presented as MAPs, resulted in the induction of anti-peptide antibodies that inhibited the binding of MAb 19 to RSV and neutralized viral infection in vitro, with titers equivalent to those in sera from RSV-infected animals. Following RSV challenge of S1S mimotope-immunized mice, a 98.7% reduction in the titer of virus in the lungs was observed. Furthermore, there was a greatly reduced cell infiltration in the lungs of immunized mice compared to that in controls. These results indicate the potential of peptide mimotopes to protect against RSV infection without exacerbating pulmonary pathology.

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