scholarly journals Synthesis, inhibitory activity and oral dosing formulation of AV5124, the structural analogue of influenza virus endonuclease inhibitor baloxavir

2020 ◽  
Author(s):  
Andrei A Ivashchenko ◽  
Oleg D Mitkin ◽  
Jeremy C Jones ◽  
Alexander V Nikitin ◽  
Angela G Koryakova ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Protective Efficacy ◽  
Pharmacophore Model ◽  
Supramolecular Interactions ◽  
Drug Candidate ◽  
Protein Data Bank Code ◽  
Clinical Implementation

Abstract Background The development and clinical implementation of the cap-dependent endonuclease (CEN) inhibitor baloxavir marboxil was a breakthrough in influenza therapy, but it was associated with the emergence of drug-resistant variants. Objectives To design and synthesize structural analogues of CEN inhibitors and evaluate their safety, pharmacokinetics and antiviral potency in vitro and in vivo. Methods The drug candidate AV5124 and its active metabolite AV5116 were synthesized based on pharmacophore modelling. Stability in plasma and microsomes, plasma protein binding, cytotoxicity and antiviral activities were assessed in vitro. Pharmacokinetics after IV or oral administration were analysed in CD-1 mice. Acute toxicity and protective efficacy against lethal A(H1N1)pdm09 influenza virus challenge were examined in BALB/c mice. Results Pharmacophore model-assisted, 3D molecular docking predicted key supramolecular interactions of the metal-binding group and bulky hydrophobic group of AV5116 with the CEN binding site (Protein Data Bank code: 6FS6) that are essential for high antiviral activity. AV5116 inhibited influenza virus polymerase complexes in cell-free assays and replication of oseltamivir-susceptible and -resistant influenza A and B viruses at nanomolar concentrations. Notably, AV5116 was equipotent or more potent than baloxavir acid (BXA) against WT (I38-WT) viruses and viruses with reduced BXA susceptibility carrying an I38T polymerase acidic (PA) substitution. AV5116 exhibited low cytotoxicity in Madin–Darby canine kidney cells and lacked mitochondrial toxicity, resulting in favourable selective indices. Treatment with 20 or 50 mg/kg AV5124 prevented death in 60% and 100% of animals, respectively. Conclusions Overall, AV5124 and A5116 are promising inhibitors of the influenza virus CEN and warrant further development as potent anti-influenza agents.

scholarly journals Immune effects against influenza A virus and a novel DNA vaccine with co-expression of haemagglutinin- and neuraminidase-encoding genes

2009 ◽  
Vol 58 (7) ◽  
pp. 845-854 ◽  
Author(s):  
Weidong Zhang ◽  
Wanyi Li ◽  
Yan Li ◽  
Hong Li ◽  
Baoning Wang ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Dna Vaccine ◽  
Influenza A ◽  
Protective Efficacy ◽  
Survival Rates ◽  
Serum Antibody ◽  
Lethal Challenge ◽  
Vector Systems

The high variability of influenza virus causes difficulties in the control and prevention of influenza, thus seeking a promising approach for dealing with these problems is a hot topic. Haemagglutinin (HA) and neuraminidase (NA) are major surface antigens of the influenza virus, and provide effective protection against lethal challenges with this virus. We constructed a DNA vaccine (pHA-IRES2-NA) that co-expressed both HA and NA, and compared its protective efficacy and immunogenic ability with that of singly expressed HA or NA, or a mixture of the two singly expressed proteins. Our findings showed that both HA and NA proteins expressed by pHA-IRES2-NA could be detected in vivo and in vitro. The protection of DNA vaccines was evaluated by serum antibody titres, residual lung virus titres and survival rates of the mice. In the murine model, immunization of pHA-IRES2-NA generated significant anti-HA and anti-NA antibody, increased the percentage of CD8+ cells and gamma interferon-producing CD8+ cells and the ratio of Th1/Th2 (T helper) cells, which was comparable to the effects of immunization with HA or NA DNA alone or with a mixture of HA and NA DNA. All the mice inoculated by pHA-IRES2-NA resisted the lethal challenge by homologous influenza virus and survived with low lung virus titre. In addition, previous studies reported that co-expression allowed higher-frequency transduction compared to co-transduction of separated vector systems encoding different genes. The novel HA and NA co-expression DNA vaccine is a successful alternative to using a mixture of purified HA and NA proteins or HA and NA DNA.

scholarly journals In VitroSusceptibility of Canine Influenza A (H3N8) Virus to Nitazoxanide and Tizoxanide

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Laura V. Ashton ◽  
Robert L. Callan ◽  
Sangeeta Rao ◽  
Gabriele A. Landolt
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
The United States ◽  
Canine Influenza Virus ◽  
Valuable Adjunct ◽  
Canine Influenza ◽  
The Impact ◽  
H3n8 Virus

Infection of dogs with canine influenza virus (CIV) is considered widespread throughout the United States following the first isolation of CIV in 2004. While vaccination against influenza A infection is a common and important practice for disease control, antiviral therapy can serve as a valuable adjunct in controlling the impact of the disease. In this study, we examined the antiviral activity of nitazoxanide (NTZ) and tizoxanide (TIZ) against three CIV isolatesin vitro. NTZ and TIZ inhibited virus replication of all CIVs with 50% and 90% inhibitory concentrations ranging from 0.17 to 0.21 μMand from 0.60 to 0.76 μM, respectively. These results suggest that NTZ and TIZ are effective against CIV and may be useful for treatment of canine influenza in dogs but further investigation of thein vivoefficacy against CIV as well as the drug's potential for toxicity in dogs is needed.

scholarly journals Role of Initiating Nucleoside Triphosphate Concentrations in the Regulation of Influenza Virus Replication and Transcription

2008 ◽  
Vol 82 (14) ◽  
pp. 6902-6910 ◽  
Author(s):  
Frank T. Vreede ◽  
Hugh Gifford ◽  
George G. Brownlee
Keyword(s):  
Influenza Virus ◽  
Virus Replication ◽  
Influenza A ◽  
De Novo ◽  
Nucleoside Triphosphate ◽  
Ribonucleoprotein Complexes ◽  
Influenza Virus Replication ◽  
High Concentrations

ABSTRACT The mechanisms regulating the synthesis of mRNA, cRNA, and viral genomic RNA (vRNA) by the influenza A virus RNA-dependent RNA polymerase are not fully understood. Previous studies in our laboratory have shown that virion-derived viral ribonucleoprotein complexes synthesize both mRNA and cRNA in vitro and early in the infection cycle in vivo. Our continued studies showed that de novo synthesis of cRNA in vitro is more sensitive to the concentrations of ATP, CTP, and GTP than capped-primer-dependent synthesis of mRNA. Using rescued recombinant influenza A/WSN/33 viruses, we now demonstrate that the 3′-terminal sequence of the vRNA promoter dictates the requirement for a high nucleoside triphosphate (NTP) concentration during de novo-initiated replication to cRNA, whereas this is not the case for the extension of capped primers during transcription to mRNA. In contrast to some other viral polymerases, for which only the initiating NTP is required at high concentrations, influenza virus polymerase requires high concentrations of the first three NTPs. In addition, we show that base pair mutations in the vRNA promoter can lead to nontemplated dead-end mutations during replication to cRNA in vivo. Based on our observations, we propose a new model for the de novo initiation of influenza virus replication.

scholarly journals Δ12-Prostaglandin J2 Is a Potent Inhibitor of Influenza A Virus Replication

2000 ◽  
Vol 44 (1) ◽  
pp. 200-204 ◽  
Author(s):  
Francesca Pica ◽  
Anna Teresa Palamara ◽  
Antonio Rossi ◽  
Alessandra De Marco ◽  
Carla Amici ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Heat Shock ◽  
Influenza A Virus ◽  
Influenza A ◽  
Potent Inhibitor ◽  
Influenza Virus Infection ◽  
H1n1 Infection ◽  
Shock Proteins

ABSTRACT 9-Deoxy-Δ9,Δ12-13,14-dihydro-prostaglandin D2 (Δ12-PGJ2), a natural cyclopentenone metabolite of prostaglandin D2, is shown to possess therapeutic efficacy against influenza A virus A/PR8/34 (H1N1) infection in vitro and in vivo. The results indicate that the antiviral activity is associated with induction of cytoprotective heat shock proteins and suggest novel strategies for treatment of influenza virus infection.

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 A Novel Sulfonated Derivative of β-Cyclodextrin Effectively Inhibits Influenza A Virus Infection in vitro and in vivo

Acta Naturae ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 20-30 ◽  
Author(s):  
E. P. Goncharova ◽  
Y. A. Kostyro ◽  
A. V. Ivanov ◽  
M. A. Zenkova
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
High Efficiency ◽  
Influenza Infection ◽  
Lethal Infection ◽  
Novel Drugs ◽  
Infected Cells ◽  
Low Toxicity

The development of novel drugs against the influenza virus with high efficiency and low toxicity is an urgent and important task. Previous reports have demonstrated that compounds based on sulfo derivatives of oligo- and polysaccharides possess high antiviral activity. In this study, we have examined the ability of a novel sulfonated derivative of -cyclodextrin (KS-6469) to inhibit the influenza virus A/WSN/33 (H1N1) infection in vitro and in vivo. The antiviral potential of KS-6469 against the influenza virus was evaluated in Madin-Darby Canine Kidney epithelial cells treated with serially diluted KS-6469. We found out that KS-6469 completely inhibited viral reproduction after treatment of the infected cells with the compound for 48 h. Our data show that double intranasal treatment of mice with KS-6469 fully protected the animals from a lethal infection and significantly decreased the viral titers in the lungs of the infected animals. Thus, the novel sulfonated -cyclodextrin derivative KS-6469 is a promising candidate for the development of antiviral drugs for preventing and treating the influenza infection.

scholarly journals Ethanol Extract of Caesalpinia decapetala Inhibits Influenza Virus Infection In Vitro and In Vivo

Viruses ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 557 ◽  
Author(s):  
Li Zhang ◽  
Jungang Chen ◽  
Chang Ke ◽  
Haiwei Zhang ◽  
Shoujun Zhang ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Antiviral Agents ◽  
Influenza Virus Infection ◽  
Virus Titer ◽  
Ethanol Extract ◽  
Influenza Viruses ◽  
Virus Infections

Influenza virus infections can lead to viral pneumonia and acute respiratory distress syndrome in severe cases, causing significant morbidity and mortality and posing a great threat to human health. Because of the diversity of influenza virus strains and drug resistance to the current direct antiviral agents, there have been no effective drugs as yet to cure all patients infected by influenza viruses. Natural products from plants contain compounds with diverse structures that have the potential to interact with multiple host and virus factors. In this study, we identified the ethanol extract of Caesalpinia decapetala (Roth) Alston (EEC) as an inhibitor against the replication of a panel of influenza A and B viruses both on human pulmonary epithelial A549 and human monocytic U937 cells. The animal study revealed that EEC administration reduces the weight loss and improves the survival rate of mice infected with lethal influenza virus. Also, EEC treatment attenuated lung injury and reduced virus titer significantly. In conclusion, we showed that EEC has antiviral activity both in vitro and in vivo, suggesting that the plant C. decapetala has the potential to be further developed as a resource of new anti-influenza drugs.

scholarly journals Pudilan xiaoyan oral liquid (PDL) inhibit the replication of influenza A virus through regulating TLR3/MyD88 signaling pathway

2022 ◽  
Author(s):  
Zheng Zhihui ◽  
Yuqian Zhang ◽  
Gang Tian ◽  
Zehua Wang ◽  
Ronghua Wang ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza A Virus ◽  
Influenza A ◽  
Antiviral Effect ◽  
Inhibitory Effect ◽  
Tnf Α ◽  
Oral Liquid ◽  
Ifn Γ

Abstract Background Pudilan Xiaoyan Oral Liquid (PDL) as a famous Chinese patent medicine has been widely used for treating upper respiratory tract infection. However, the antiviral effect of PDL remain unclear. Here, the antiviral effect of in vitro and in vivo of PDL against influenza A virus were for the first time investigated. Methods The in vitro inhibitory effect of PDL on influenza A virus was investigated using MDCK cell model. The in vivo inhibitory effect on influenza virus pneumonia was evaluated with the ICR female mice (14-16 g) model infected by influenza A virus (A/FM/1/47, H1N1, mouse-adapted). Moreover, expression levels of inflammatory cytokines including TNF-α, IP10, IL-10, IL-1β, IL-6 and IFN-γ in lung tissue were measured by qRT-PCR. The potential mechanism of PDL against acute lung injury caused by influenza A virus was investigated by RT-PCR and Western blot. Results Our results indicated that in vitro PDL has a broad-spectrum inhibitory effect on different subtypes of influenza A viruses and in vivo PDL could dose-dependently prevent weight loss of mice, increase food intake and reduce mortality caused by influenza A H1N1 virus. Furthermore, PDL could markedly improve the acute lung injury caused by influenza A virus and significantly reduce the mRNA levels of inflammatory factors such as TNF-α, IP10, IL-10, IL-1β, IL-6, and IFN-γ. Mechanistic research indicated that the protective effect of PDL on viral pneumonia might be achieved by inhibiting TLR3/MyD88/IRAK4/TRAF3 signaling pathway. Conclusion PDL not only showed a good inhibitory effect on influenza A virus in vitro, but also exhibited a significant protective effect against lethal influenza virus infection in vivo. These findings provide evidence for the clinical treatment of influenza A virus infection with PDL.

scholarly journals Direct Evidence that the Poly(A) Tail of Influenza A Virus mRNA Is Synthesized by Reiterative Copying of a U Track in the Virion RNA Template

1999 ◽  
Vol 73 (4) ◽  
pp. 3473-3476 ◽  
Author(s):  
Leo L. M. Poon ◽  
David C. Pritlove ◽  
Ervin Fodor ◽  
George G. Brownlee
Keyword(s):  
Influenza Virus ◽  
Experimental Evidence ◽  
Influenza A Virus ◽  
Influenza A ◽  
Direct Evidence ◽  
Evidence Based ◽  
Direct Experimental Evidence ◽  
Plausible Hypothesis

ABSTRACT The poly(A) tail of influenza virus mRNA is thought to be synthesized by reiterative copying of the U track near the 5′ end of the virion RNA template. This has been widely accepted as a plausible hypothesis, but until now there has been no direct experimental evidence for it. Here, we report such direct evidence based on the fact that (i) replacing the U track with an A track directs synthesis of products with poly(U) tails, both in vitro and in vivo, and (ii) interrupting the U track abolishes polyadenylation in vitro.

scholarly journals Identification of a Novel Viral Protein Expressed from the PB2 Segment of Influenza A Virus

2015 ◽  
Vol 90 (1) ◽  
pp. 444-456 ◽  
Author(s):  
Seiya Yamayoshi ◽  
Mariko Watanabe ◽  
Hideo Goto ◽  
Yoshihiro Kawaoka
Keyword(s):  
Influenza Virus ◽  
Influenza A Virus ◽  
Viral Protein ◽  
Influenza A ◽  
Viral Infections ◽  
Viral Proteins ◽  
Wild Type Virus ◽  
Infected Cells

ABSTRACTOver the past 2 decades, several novel influenza virus proteins have been identified that modulate viral infectionsin vitroand/orin vivo. The PB2 segment, which is one of the longest influenza A virus segments, is known to encode only one viral protein, PB2. In the present study, we used reverse transcription-PCR (RT-PCR) targeting viral mRNAs transcribed from the PB2 segment to look for novel viral proteins encoded by spliced mRNAs. We identified a new viral protein, PB2-S1, encoded by a novel spliced mRNA in which the region corresponding to nucleotides 1513 to 1894 of the PB2 mRNA is deleted. PB2-S1 was detected in virus-infected cells and in cells transfected with a protein expression plasmid encoding PB2. PB2-S1 localized to mitochondria, inhibited the RIG-I-dependent interferon signaling pathway, and interfered with viral polymerase activity (dependent on its PB1-binding capability). The nucleotide sequences around the splicing donor and acceptor sites for PB2-S1 were highly conserved among pre-2009 human H1N1 viruses but not among human H1N1pdm and H3N2 viruses. PB2-S1-deficient viruses, however, showed growth kinetics in MDCK cells and virulence in mice similar to those of wild-type virus. The biological significance of PB2-S1 to the replication and pathogenicity of seasonal H1N1 influenza A viruses warrants further investigation.IMPORTANCETranscriptome analysis of cells infected with influenza A virus has improved our understanding of the host response to viral infection, because such analysis yields considerable information about bothin vitroandin vivoviral infections. However, little attention has been paid to transcriptomes derived from the viral genome. Here we focused on the splicing of mRNA expressed from the PB2 segment and identified a spliced viral mRNA encoding a novel viral protein. This result suggests that other, as yet unidentified viral proteins encoded by spliced mRNAs could be expressed in virus-infected cells. A viral transcriptome including the viral spliceosome should be evaluated to gain new insights into influenza virus infection.

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