scholarly journals Synergistic Antiviral Activity of S-033188/S-033447, a Novel Inhibitor of Influenza Virus Cap-Dependent Endonuclease, in Combination with Neuraminidase Inhibitors In Vitro

2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S371-S371 ◽  
Author(s):  
Mitsutaka Kitano ◽  
Atsuko Yamamoto ◽  
Takeshi Noshi ◽  
Makoto Kawai ◽  
Ryu Yoshida ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Cultured Cells ◽  
H1n1 Virus ◽  
Mdck Cells ◽  
Active Form ◽  
Neuraminidase Inhibitors ◽  
Dependent Endonuclease ◽  
Influenza A H1n1

Abstract Background S-033447, an active form of orally available prodrug S-033188, is a novel small molecule inhibitor of cap-dependent endonuclease that is essential for influenza virus transcription and replication. In this study, we evaluated the inhibitory effect of S-033188 in combination with neuraminidase inhibitors on the replication of influenza A/H1N1 virus in cultured cells. Methods The inhibitory effects of S-033447 in combination with NA inhibitors on the cytopathic effect of A/PR/8/34 strain in Madin–Darby canine kidney cells cultured for 2 days were tested and EC50 were determined. The combination index (CI), which were obtained when S-033188 and NA inhibitor were added at the closest ratio of each EC50 value, were used for the evaluation of these combinational effects (Table 1). CI values were calculated by the Chou and Talalay method, in which combinational effect were determined according to the criteria as follows: synergistic if CI ≤ 0.8, additive if 0.8 < CI < 1.2, and antagonistic if CI ≥ 1.2. CI = (DA/A + B)/DA + (DB/A + B)/DB + (DA/A + B × DB/A + B)/(DA × DB) DA: the EC50 of S-033447 DB: the EC50 of NA inhibitor DA/A + B: the concentration of S-033447 giving 50% inhibition in combination with NA inhibitor at the closest ratio of each EC50 value DB/A + B: the concentration of NA inhibitor giving 50% inhibition in combination with S-033447 at the closest ratio of each EC50 value Results All CI values were lower than 0.8, under the condition that both S-033447 and NA inhibitor (oseltamivir acid, zanamivir hydrate, laninamivir, or peramivir trihydrate) were added at the closest ratio of each EC50 value (Table 1). Conclusion S-033447 in combination with oseltamivir acid, zanamivir hydrate, laninamivir, or peramivir trihydrate synergistically inhibited the replication of influenza A/H1N1 virus in MDCK cells. Disclosures All authors: No reported disclosures.

scholarly journals Overexpression of the α-2,6-Sialyltransferase in MDCK Cells Increases Influenza Virus Sensitivity to Neuraminidase Inhibitors

2003 ◽  
Vol 77 (15) ◽  
pp. 8418-8425 ◽  
Author(s):  
Mikhail Matrosovich ◽  
Tatyana Matrosovich ◽  
Jackie Carr ◽  
Noel A. Roberts ◽  
Hans-Dieter Klenk
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Cultured Cells ◽  
Mdck Cells ◽  
Sialic Acids ◽  
Neuraminidase Inhibitors ◽  
Human Influenza ◽  
Oseltamivir Carboxylate ◽  
Human Influenza Virus ◽  
Human Virus

ABSTRACT No reliable cell culture assay is currently available for monitoring human influenza virus sensitivity to neuraminidase inhibitors (NAI). This can be explained by the observation that because of a low concentration of sialyl-α2,6-galactose (Sia[α2,6]Gal)-containing virus receptors in conventional cell lines, replication of human virus isolates shows little dependency on viral neuraminidase. To test whether overexpression of Sia(α2,6)Gal moieties in cultured cells could make them suitable for testing human influenza virus sensitivity to NAI, we stably transfected MDCK cells with cDNA of human 2,6-sialyltransferase (SIAT1). Transfected cells expressed twofold-higher amounts of 6-linked sialic acids and twofold-lower amounts of 3-linked sialic acids than parent MDCK cells as judged by staining with Sambucus nigra agglutinin and Maackia amurensis agglutinin, respectively. After transfection, binding of a clinical human influenza virus isolate was increased, whereas binding of its egg-adapted variant which preferentially bound 3-linked receptors was decreased. The sensitivity of human influenza A and B viruses to the neuraminidase inhibitor oseltamivir carboxylate was substantially improved in the SIAT1-transfected cell line and was consistent with their sensitivity in neuraminidase enzyme assay and with the hemagglutinin (HA) receptor-binding phenotype. MDCK cells stably transfected with SIAT1 may therefore be a suitable system for testing influenza virus sensitivity to NAI.

In vitro Inhibitory Effects of Combinations of anti-Influenza Agents

1995 ◽  
Vol 6 (2) ◽  
pp. 109-113 ◽  
Author(s):  
L. K. Madren ◽  
C. Shipman ◽  
F. G. Hayden
Keyword(s):  
Viral Replication ◽  
Influenza A ◽  
H1n1 Virus ◽  
Mdck Cells ◽  
Clinical Isolates ◽  
H1n1 Subtype ◽  
Additive Effects ◽  
Inhibitory Effects ◽  
Influenza A H1n1

To assess the possible interactions among candidate anti-influenza agents, dual combinations of rimantadine, ribavirin, 2′-deoxy-2′-fluoroguanosine (2-FDG) and 4-guanidino-Neu5Ac2en (GG167) were tested against clinical isolates of influenza A H3N2 and H1N1 subtype viruses in MDCK cells by ELISA. Each of the dual combinations showed additive effects, except for the combination of 2-FDG and ribavirin which was synergistic against the influenza A (H1N1) virus. However, this combination also showed enhanced cytotoxicity. In this assay system, influenza agents with differing mechanisms of antiviral interaction interacted in an additive fashion with respect to inhibition of viral replication.

scholarly journals A Novel Natural Influenza A H1N1 Virus Neuraminidase Inhibitory Peptide Derived from Cod Skin Hydrolysates and Its Antiviral Mechanism

Marine Drugs ◽  
2018 ◽  
Vol 16 (10) ◽  
pp. 377 ◽  
Author(s):  
Jianpeng Li ◽  
Yiping Chen ◽  
Ning Yuan ◽  
Mingyong Zeng ◽  
Yuanhui Zhao ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
H1n1 Virus ◽  
Mdck Cells ◽  
Host Cells ◽  
Dependent Manner ◽  
Hydrogen Binding ◽  
Inhibitory Peptide ◽  
Influenza A H1n1 ◽  
Antiviral Mechanism

In this paper, a novel natural influenza A H1N1 virus neuraminidase (NA) inhibitory peptide derived from cod skin hydrolysates was purified and its antiviral mechanism was explored. From the hydrolysates, novel efficient NA-inhibitory peptides were purified by a sequential approach utilizing an ultrafiltration membrane (5000 Da), sephadex G-15 gel column and reverse-phase high-performance liquid chromatography (RP-HPLC). The amino acid sequence of the pure peptide was determined by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS) was PGEKGPSGEAGTAGPPGTPGPQGL, with a molecular weight of 2163 Da. The analysis of the Lineweacer–Burk model indicated that the peptide was a competitive NA inhibitor with Ki of 0.29 mM and could directly bind free enzymes. In addition, docking studies suggested that hydrogen binding might be the driving force for the binding affinity of PGEKGPSGEAGTAGPPGTPGPQGL to NA. The cytopathic effect reduction assay showed that the peptide PGEKGPSGEAGTAGPPGTPGPQGL protected Madin–Darby canine kidney (MDCK) cells from viral infection and reduced the viral production in a dose-dependent manner. The EC50 value was 471 ± 12 μg/mL against H1N1. Time-course analysis showed that PGEKGPSGEAGTAGPPGTPGPQGL inhibited influenza virus in the early stage of the infectious cycle. The virus titers assay indicated that the NA-inhibitory peptide PGEKGPSGEAGTAGPPGTPGPQGL could directly affect the virus toxicity and adsorption by host cells, further proving that the peptide had an anti-viral effect with multiple target sites. The activity of NA-inhibitory peptide was almost inactivated during the simulated in vitro gastrointestinal digestion, suggesting that oral administration is not recommended. The peptide PGEKGPSGEAGTAGPPGTPGPQGL acts as a neuraminidase blocker to inhibit influenza A virus in MDCK cells. Thus, the peptide PGEKGPSGEAGTAGPPGTPGPQGL has potential utility in the treatment of the influenza virus infection.

scholarly journals Detailed Molecular Interactions of Favipiravir with SARS-CoV-2, SARS-CoV, MERS-CoV, and Influenza Virus Polymerases In Silico

2020 ◽  
Vol 8 (10) ◽  
pp. 1610 ◽  
Author(s):  
Mitsuru Sada ◽  
Takeshi Saraya ◽  
Haruyuki Ishii ◽  
Kaori Okayama ◽  
Yuriko Hayashi ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Molecular Interactions ◽  
In Silico ◽  
Influenza A ◽  
Active Sites ◽  
Active Form ◽  
Antiviral Drug ◽  
Virus Rna ◽  
Influenza A H1n1 ◽  
In Silico Studies

Favipiravir was initially developed as an antiviral drug against influenza and is currently used in clinical trials against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection (COVID-19). This agent is presumably involved in RNA chain termination during influenza virus replication, although the molecular interactions underlying its potential impact on the coronaviruses including SARS-CoV-2, SARS-CoV, and Middle East respiratory syndrome coronavirus (MERS-CoV) remain unclear. We performed in silico studies to elucidate detailed molecular interactions between favipiravir and the SARS-CoV-2, SARS-CoV, MERS-CoV, and influenza virus RNA-dependent RNA polymerases (RdRp). As a result, no interactions between favipiravir ribofuranosyl-5′-triphosphate (F-RTP), the active form of favipiravir, and the active sites of RdRps (PB1 proteins) from influenza A (H1N1)pdm09 virus were found, yet the agent bound to the tunnel of the replication genome of PB1 protein leading to the inhibition of replicated RNA passage. In contrast, F-RTP bound to the active sites of coronavirus RdRp in the presence of the agent and RdRp. Further, the agent bound to the replicated RNA terminus in the presence of agent, magnesium ions, nucleotide triphosphate, and RdRp proteins. These results suggest that favipiravir exhibits distinct mechanisms of action against influenza virus and various coronaviruses.

HA1-2-fljB Vaccine Induces Immune Responses against Pandemic Swine-Origin H1N1 Influenza Virus in Mice

2016 ◽  
Vol 26 (6) ◽  
pp. 422-432 ◽  
Author(s):  
Xilong Kang ◽  
Yun Yang ◽  
Yang Jiao ◽  
Hongqin Song ◽  
Li Song ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
H1n1 Virus ◽  
Influenza Virus Infection ◽  
Candidate Vaccine ◽  
Major Barrier ◽  
Excellent Starting Point ◽  
Starting Point ◽  
Influenza A H1n1 ◽  
N Terminus

In 2009, a novel pandemic swine-origin influenza A (H1N1) virus caused a public emergency of international concern. Vaccination is the primary strategy for the control of influenza epidemics. However, the poor immunopotency of many vaccine antigens is a major barrier to the development of effective vaccines against influenza. Flagellin, a Toll-like receptor 5 (TLR5) ligand, has been used as an adjuvant to enhance the immunopotency of vaccines in preclinical studies. Here, we developed a recombinant candidate vaccine, HA1-2-fljB, in which the globular head of the hemagglutinin (HA) antigen (residues 62-284) from H1N1 virus was fused genetically to the N-terminus of <i>Salmonella typhimurium</i> &#xFB02;jB. The recombinant HA1-2-fljB protein was expressed efficiently in<i> Escherichia coli</i>, and the immunogenicity and protective efficacy of recombinant HA1-2-fljB were evaluated in a mouse model. Immunization with HA1-2-fljB elicited robust IgG antibodies and neutralizing antibodies and completely protected the mice against infection by swine-origin influenza A/swine/Jangsu/38/2010 (H1N1). These results suggest that HA antigen placed at the N-terminus of flagellin is also an excellent starting point for creating a fusion HA1-2-fljB protein as a candidate vaccine, and the recombinant HA1-2-fljB protein will contribute to the development of a more effective vaccine against swine-origin influenza virus infection.

scholarly journals Contemporary Seasonal Influenza A (H1N1) Virus Infection Primes for a More Robust Response To Split Inactivated Pandemic Influenza A (H1N1) Virus Vaccination in Ferrets

2010 ◽  
Vol 17 (12) ◽  
pp. 1998-2006 ◽  
Author(s):  
Ali H. Ellebedy ◽  
Thomas P. Fabrizio ◽  
Ghazi Kayali ◽  
Thomas H. Oguin ◽  
Scott A. Brown ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Pandemic Influenza ◽  
Influenza A ◽  
Seasonal Influenza ◽  
H1n1 Virus ◽  
H1n1 Influenza ◽  
Influenza Viruses ◽  
Inactivated Vaccine ◽  
H1n1 Influenza Virus ◽  
Influenza A H1n1

ABSTRACT Human influenza pandemics occur when influenza viruses to which the population has little or no immunity emerge and acquire the ability to achieve human-to-human transmission. In April 2009, cases of a novel H1N1 influenza virus in children in the southwestern United States were reported. It was retrospectively shown that these cases represented the spread of this virus from an ongoing outbreak in Mexico. The emergence of the pandemic led to a number of national vaccination programs. Surprisingly, early human clinical trial data have shown that a single dose of nonadjuvanted pandemic influenza A (H1N1) 2009 monovalent inactivated vaccine (pMIV) has led to a seroprotective response in a majority of individuals, despite earlier studies showing a lack of cross-reactivity between seasonal and pandemic H1N1 viruses. Here we show that previous exposure to a contemporary seasonal H1N1 influenza virus and to a lesser degree a seasonal influenza virus trivalent inactivated vaccine is able to prime for a higher antibody response after a subsequent dose of pMIV in ferrets. The more protective response was partially dependent on the presence of CD8+ cells. Two doses of pMIV were also able to induce a detectable antibody response that provided protection from subsequent challenge. These data show that previous infection with seasonal H1N1 influenza viruses likely explains the requirement for only a single dose of pMIV in adults and that vaccination campaigns with the current pandemic influenza vaccines should reduce viral burden and disease severity in humans.

Comprehensive assessment of 2009 pandemic influenza A (H1N1) virus drug susceptibility in vitro

2010 ◽  
Vol 15 (8) ◽  
pp. 1151-1159 ◽  
Author(s):  
Larisa V Gubareva ◽  
A Angelica Trujillo ◽  
Margaret Okomo-Adhiambo ◽  
Vasiliy P Mishin ◽  
Varough M Deyde ◽  
...  
Keyword(s):  
Pandemic Influenza ◽  
Influenza A ◽  
H1n1 Virus ◽  
Drug Susceptibility ◽  
Comprehensive Assessment ◽  
Influenza A H1n1

scholarly journals Heterosubtypic Protection Conferred by the Human Monoclonal Antibody PN-SIA28 against Influenza A Virus Lethal Infections in Mice

2015 ◽  
Vol 59 (5) ◽  
pp. 2647-2653 ◽  
Author(s):  
Miguel Retamal ◽  
Yacine Abed ◽  
Chantal Rhéaume ◽  
Francesca Cappelletti ◽  
Nicola Clementi ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Body Weight ◽  
Influenza Virus ◽  
Influenza A ◽  
Human Monoclonal Antibody ◽  
Influenza A Viruses ◽  
Virus Challenge ◽  
Influenza A H1n1

ABSTRACTPN-SIA28 is a human monoclonal antibody (Hu-MAb) targeting highly conserved epitopes within the stem portion of the influenza virus hemagglutinin (HA) (N. Clementi, et al, PLoS One 6:e28001, 2011,http://dx.doi.org/10.1371/journal.pone.0028001). Previousin vitrostudies demonstrated PN-SIA28 neutralizing activities against phylogenetically divergent influenza A subtypes. In this study, the protective activity of PN-SIA28 was evaluated in mice inoculated with lethal influenza A/WSN/33 (H1N1), A/Quebec/144147/09 (H1N1)pdm09, and A/Victoria/3/75 (H3N2) viruses. At 24 h postinoculation (p.i.), animals received PN-SIA28 intraperitoneally (1 or 10 mg/kg of body weight) or 10 mg/kg of unrelated Hu-MAb (mock). Body weight loss and mortality rate (MR) were recorded for 14 days postinfection (p.i.). Lung viral titers (LVT) were determined at day 5 p.i. In A/WSN/33 (H1N1)-infected groups, all untreated and mock-receiving mice died, whereas MRs of 87.5% and 25% were observed in mice that received PN-SIA28 1 and 10 mg/kg, respectively. In influenza A(H1N1) pdm09-infected groups, an MR of 75% was recorded for untreated and mock-treated groups, whereas the PN-SIA28 1-mg/kg and 10-mg/kg groups had rates of 62.5% and 0%, respectively. In A/Victoria/3/75 (H3N2)-infected animals, untreated and mock-treated animals had MRs of 37.5% and 25%, respectively, and no mortalities were recorded after PN-SIA28 treatments. Accordingly, PN-SIA28 treatments significantly reduced weight losses and resulted in a ≥1-log reduction in LVT compared to the control in all infection groups. This study confirms that antibodies targeting highly conserved epitopes in the influenza HA stem region, like PN-SIA28, not only neutralize influenza A viruses of clinically relevant subtypesin vitrobut also, more importantly, protect from a lethal influenza virus challengein vivo.

scholarly journals Triple-Combination Antiviral Drug for Pandemic H1N1 Influenza Virus Infection in Critically Ill Patients on Mechanical Ventilation

2011 ◽  
Vol 55 (12) ◽  
pp. 5703-5709 ◽  
Author(s):  
Won-Young Kim ◽  
Gee Young Suh ◽  
Jin Won Huh ◽  
Sung-Han Kim ◽  
Min-ju Kim ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Critically Ill ◽  
Influenza A ◽  
Antiviral Drug ◽  
Influenza Virus Infection ◽  
Antiviral Drugs ◽  
Triple Combination ◽  
Influenza A H1n1

ABSTRACTA recentin vitrostudy showed that the three compounds of antiviral drugs with different mechanisms of action (amantadine, ribavirin, and oseltamivir) could result in synergistic antiviral activity against influenza virus. However, no clinical studies have evaluated the efficacy and safety of combination antiviral therapy in patients with severe influenza illness. A total of 245 adult patients who were critically ill with confirmed pandemic influenza A/H1N1 2009 (pH1N1) virus infection and were admitted to one of the intensive care units of 28 hospitals in Korea were reviewed. Patients who required ventilator support and received either triple-combination antiviral drug (TCAD) therapy or oseltamivir monotherapy were analyzed. A total of 127 patients were included in our analysis. Among them, 24 patients received TCAD therapy, and 103 patients received oseltamivir monotherapy. The 14-day mortality was 17% in the TCAD group and 35% in the oseltamivir group (P= 0.08), and the 90-day mortality was 46% in the TCAD group and 59% in the oseltamivir group (P= 0.23). None of the toxicities attributable to antiviral drugs occurred in either group of our study, including hemolytic anemia and hepatic toxicities related to the use of ribavirin. Logistic regression analysis indicated that the odds ratio for the association of TCAD with 90-day mortality was 0.58 (95% confidence interval, 0.24 to 1.42;P= 0.24). Although this study was retrospective and did not provide virologic outcomes, our results suggest that the treatment outcome of the triple combination of amantadine, ribavirin, and oseltamivir was comparable to that of oseltamivir monotherapy.

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