1
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Taniguchi K, Noshi T, Omoto S, Sato A, Shishido T, Matsuno K, Okamatsu M, Krauss S, Webby RJ, Sakoda Y, Kida H. The impact of PA/I38 substitutions and PA polymorphisms on the susceptibility of zoonotic influenza A viruses to baloxavir. Arch Virol 2024; 169:29. [PMID: 38216710 PMCID: PMC10786730 DOI: 10.1007/s00705-023-05958-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 11/28/2023] [Indexed: 01/14/2024]
Abstract
Genetic reassortment of avian, swine, and human influenza A viruses (IAVs) poses potential pandemic risks. Surveillance is important for influenza pandemic preparedness, but the susceptibility of zoonotic IAVs to the cap-dependent endonuclease inhibitor baloxavir acid (BXA) has not been thoroughly researched. Although an amino acid substitution at position 38 in the polymerase acidic protein (PA/I38) in seasonal IAVs reduces BXA susceptibility, PA polymorphisms at position 38 are rarely seen in zoonotic IAVs. Here, we examined the impact of PA/I38 substitutions on the BXA susceptibility of recombinant A(H5N1) viruses. PA mutants that harbored I38T, F, and M were 48.2-, 24.0-, and 15.5-fold less susceptible, respectively, to BXA than wild-type A(H5N1) but were susceptible to the neuraminidase inhibitor oseltamivir acid and the RNA polymerase inhibitor favipiravir. PA mutants exhibited significantly impaired replicative fitness in Madin-Darby canine kidney cells at 24 h postinfection. In addition, in order to investigate new genetic markers for BXA susceptibility, we screened geographically and temporally distinct IAVs isolated worldwide from birds and pigs. The results showed that BXA exhibited antiviral activity against avian and swine viruses with similar levels to seasonal isolates. All viruses tested in the study lacked the PA/I38 substitution and were susceptible to BXA. Isolates harboring amino acid polymorphisms at positions 20, 24, and 37, which have been implicated in the binding of BXA to the PA endonuclease domain, were also susceptible to BXA. These results suggest that monitoring of the PA/I38 substitution in animal-derived influenza viruses is important for preparedness against zoonotic influenza virus outbreaks.
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Affiliation(s)
- Keiichi Taniguchi
- Shionogi Pharmaceutical Research Center, Shionogi & Co., Ltd., Toyonaka, Osaka, Japan
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Takeshi Noshi
- Shionogi Pharmaceutical Research Center, Shionogi & Co., Ltd., Toyonaka, Osaka, Japan
| | - Shinya Omoto
- Shionogi Pharmaceutical Research Center, Shionogi & Co., Ltd., Toyonaka, Osaka, Japan
| | - Akihiko Sato
- Shionogi Pharmaceutical Research Center, Shionogi & Co., Ltd., Toyonaka, Osaka, Japan
- International Institute for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, Japan
- Institute for Vaccine Research and Development, HU-IVReD, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Takao Shishido
- Shionogi Pharmaceutical Research Center, Shionogi & Co., Ltd., Toyonaka, Osaka, Japan.
| | - Keita Matsuno
- International Institute for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, Japan
- Institute for Vaccine Research and Development, HU-IVReD, Hokkaido University, Sapporo, Hokkaido, Japan
- International Collaboration Unit, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, Japan
- One Health Research Center, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Masatoshi Okamatsu
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Scott Krauss
- St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Richard J Webby
- St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Yoshihiro Sakoda
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
- Institute for Vaccine Research and Development, HU-IVReD, Hokkaido University, Sapporo, Hokkaido, Japan
- International Collaboration Unit, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, Japan
- One Health Research Center, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Hiroshi Kida
- International Institute for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, Japan
- Institute for Vaccine Research and Development, HU-IVReD, Hokkaido University, Sapporo, Hokkaido, Japan
- International Collaboration Unit, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, Japan
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2
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Yuyukina SK, Zharkov DO. Mechanisms of Coronavirus Genome Stability As Potential Targets for Antiviral Drugs. HERALD OF THE RUSSIAN ACADEMY OF SCIENCES 2022; 92:470-478. [PMID: 36091852 PMCID: PMC9447942 DOI: 10.1134/s1019331622040256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 02/25/2022] [Accepted: 03/14/2022] [Indexed: 06/15/2023]
Abstract
The COVID-19 pandemic has made it necessary to create antivirals active against the SARS-CoV-2 coronavirus. One of the widely used strategies to fight off viral infections is the use of modified nucleoside analogues that inhibit viral replication by incorporating DNA or RNA into the growing chain, thus stopping its synthesis. The difficulty of using this method of treatment in the case of SARS-CoV-2 is that coronaviruses have an effective mechanism for maintaining genome stability. Its central element is the nsp14 protein, which is characterized by exonuclease activity, due to which incorrectly included and noncanonical nucleotides are removed from the 3' end of the growing RNA chain. Inhibitors of nsp14 exonuclease and nucleoside analogues resistant to its action are viewed as potential targets for anticoronavirus therapy.
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Affiliation(s)
- S. K. Yuyukina
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
- Novosibirsk State University, Novosibirsk, Russia
| | - D. O. Zharkov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
- Novosibirsk State University, Novosibirsk, Russia
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3
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Young A. T cells in SARS-CoV-2 infection and vaccination. Ther Adv Vaccines Immunother 2022; 10:25151355221115011. [PMID: 36051003 PMCID: PMC9425900 DOI: 10.1177/25151355221115011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 07/04/2022] [Indexed: 12/24/2022] Open
Abstract
While antibodies garner the lion’s share of attention in SARS-CoV-2 immunity, cellular immunity (T cells) may be equally, if not more important, in controlling infection. Both CD8+ and CD4+ T cells are elicited earlier and are associated with milder disease, than antibodies, and T-cell activation appears to be necessary for control of infection. Variants of concern (VOCs) such as Omicron have escaped the neutralizing antibody responses after two mRNA vaccine doses, but T-cell immunity is largely intact. The breadth and patient-specific nature of the latter offers a formidable line of defense that can limit the severity of illness, and are likely to be responsible for most of the protection from natural infection or vaccination against VOCs which have evaded the antibody response. Comprehensive searches for T-cell epitopes, T-cell activation from infection and vaccination of specific patient groups, and elicitation of cellular immunity by various alternative vaccine modalities are here reviewed. Development of vaccines that specifically target T cells is called for, to meet the needs of patient groups for whom cellular immunity is weaker, such as the elderly and the immunosuppressed. While VOCs have not yet fully escaped T-cell immunity elicited by natural infection and vaccines, some early reports of partial escape suggest that future VOCs may achieve the dreaded result, dislodging a substantial proportion of cellular immunity, enough to cause a grave public health burden. A proactive, rather than reactive, solution which identifies and targets immutable sequences in SARS-CoV-2, not just those which are conserved, may be the only recourse humankind has to disarm these future VOCs before they disarm us.
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Affiliation(s)
- Arthur Young
- InvVax, 2265 E. Foohill Blvd., Pasadena, CA 91107, USA
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4
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Xu X, Zhang L, Chu JTS, Wang Y, Chin AWH, Chong TH, Dai Z, Poon LLM, Cheung PPH, Huang X. A novel mechanism of enhanced transcription activity and fidelity for influenza A viral RNA-dependent RNA polymerase. Nucleic Acids Res 2021; 49:8796-8810. [PMID: 34379778 PMCID: PMC8421151 DOI: 10.1093/nar/gkab660] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/13/2021] [Accepted: 07/26/2021] [Indexed: 11/13/2022] Open
Abstract
During RNA elongation, the influenza A viral (IAV) RNA-dependent RNA polymerase (RdRp) residues in the active site interact with the triphosphate moiety of nucleoside triphosphate (NTP) for catalysis. The molecular mechanisms by which they control the rate and fidelity of NTP incorporation remain elusive. Here, we demonstrated through enzymology, virology and computational approaches that the R239 and K235 in the PB1 subunit of RdRp are critical to controlling the activity and fidelity of transcription. Contrary to common beliefs that high-fidelity RdRp variants exert a slower incorporation rate, we discovered a first-of-its-kind, single lysine-to-arginine mutation on K235 exhibited enhanced fidelity and activity compared with wild-type. In particular, we employed a single-turnover NTP incorporation assay for the first time on IAV RdRp to show that K235R mutant RdRp possessed a 1.9-fold increase in the transcription activity of the cognate NTP and a 4.6-fold increase in fidelity compared to wild-type. Our all-atom molecular dynamics simulations further elucidated that the higher activity is attributed to the shorter distance between K235R and the triphosphate moiety of NTP compared with wild-type. These results provide novel insights into NTP incorporation and fidelity control mechanisms, which lay the foundation for the rational design of IAV vaccine and antiviral targets.
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Affiliation(s)
- Xinzhou Xu
- The Hong Kong University of Science and Technology-Shenzhen Research Institute, Hi-Tech Park, Nanshan, Shenzhen 518057, China.,Bioengineering Graduate Program, Department of Biological and Chemical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Lu Zhang
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Julie Tung Sem Chu
- School of Public Health, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Yuqing Wang
- The Hong Kong University of Science and Technology-Shenzhen Research Institute, Hi-Tech Park, Nanshan, Shenzhen 518057, China.,Bioengineering Graduate Program, Department of Biological and Chemical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Alex Wing Hong Chin
- School of Public Health, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China.,Centre for Immunity and Infection, Hong Kong Science Park, Hong Kong, China
| | - Tin Hang Chong
- The Hong Kong University of Science and Technology-Shenzhen Research Institute, Hi-Tech Park, Nanshan, Shenzhen 518057, China.,Department of Chemistry, State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
| | - Zixi Dai
- Department of Chemistry, State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
| | - Leo Lit Man Poon
- School of Public Health, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China.,HKU-Pasteur Research Pole, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China.,Centre for Immunity and Infection, Hong Kong Science Park, Hong Kong, China
| | - Peter Pak-Hang Cheung
- The Hong Kong University of Science and Technology-Shenzhen Research Institute, Hi-Tech Park, Nanshan, Shenzhen 518057, China.,Department of Chemistry, State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China.,Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong, China.,Li Ka Shing Institute of Health Sciences, Li Ka Shing Medical Sciences Building, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Xuhui Huang
- The Hong Kong University of Science and Technology-Shenzhen Research Institute, Hi-Tech Park, Nanshan, Shenzhen 518057, China.,Department of Chemistry, State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
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5
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Gopal V, Nilsson-Payant BE, French H, Siegers JY, Yung WS, Hardwick M, te Velthuis AJW. Zinc-Embedded Polyamide Fabrics Inactivate SARS-CoV-2 and Influenza A Virus. ACS APPLIED MATERIALS & INTERFACES 2021; 13:30317-30325. [PMID: 34180223 PMCID: PMC8262172 DOI: 10.1021/acsami.1c04412] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 06/17/2021] [Indexed: 05/18/2023]
Abstract
Influenza A viruses (IAV) and SARS-CoV-2 can spread via liquid droplets and aerosols. Face masks and other personal protective equipment (PPE) can act as barriers that prevent the spread of these viruses. However, IAV and SARS-CoV-2 are stable for hours on various materials, which makes frequent and correct disposal of these PPE important. Metal ions embedded into PPE may inactivate respiratory viruses, but confounding factors such as adsorption of viruses make measuring and optimizing the inactivation characteristics difficult. Here, we used polyamide 6.6 (PA66) fibers containing embedded zinc ions and systematically investigated if these fibers can adsorb and inactivate SARS-CoV-2 and IAV H1N1 when woven into a fabric. We found that our PA66-based fabric decreased the IAV H1N1 and SARS-CoV-2 titer by approximately 100-fold. Moreover, we found that the zinc content and the virus inactivating property of the fabric remained stable over 50 standardized washes. Overall, these results provide insights into the development of reusable PPE that offer protection against RNA virus spread.
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Affiliation(s)
- Vikram Gopal
- Ascend
Performance Materials, 1010 Travis Street, Suite 900, Houston, Texas 77002, United States
| | - Benjamin E. Nilsson-Payant
- Department
of Microbiology, Icahn School of Medicine
at Mount Sinai, New York, New York 10029, United States
| | - Hollie French
- Division
of Virology, Department of Pathology, Addenbrooke’s Hospital, University of Cambridge, Hills Road, Cambridge CB2 2QQ, U.K.
| | - Jurre Y. Siegers
- Department
of Viroscience, Erasmus University Medical
Centre, Rotterdam 3015 GD, the Netherlands
| | - Wai-shing Yung
- Ascend
Performance Materials, 1010 Travis Street, Suite 900, Houston, Texas 77002, United States
| | - Matthew Hardwick
- ResInnova
Laboratories, 8807 Colesville
Rd, 3rd Floor, Silver Spring, Maryland 20910, United
States
| | - Aartjan J. W. te Velthuis
- Division
of Virology, Department of Pathology, Addenbrooke’s Hospital, University of Cambridge, Hills Road, Cambridge CB2 2QQ, U.K.
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6
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Yin R, Luo Z, Zhuang P, Lin Z, Kwoh CK. VirPreNet: a weighted ensemble convolutional neural network for the virulence prediction of influenza A virus using all eight segments. Bioinformatics 2021; 37:737-743. [PMID: 33241321 DOI: 10.1093/bioinformatics/btaa901] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 09/29/2020] [Accepted: 10/06/2020] [Indexed: 01/16/2023] Open
Abstract
MOTIVATION Influenza viruses are persistently threatening public health, causing annual epidemics and sporadic pandemics. The evolution of influenza viruses remains to be the main obstacle in the effectiveness of antiviral treatments due to rapid mutations. Previous work has been investigated to reveal the determinants of virulence of the influenza A virus. To further facilitate flu surveillance, explicit detection of influenza virulence is crucial to protect public health from potential future pandemics. RESULTS In this article, we propose a weighted ensemble convolutional neural network (CNN) for the virulence prediction of influenza A viruses named VirPreNet that uses all eight segments. Firstly, mouse lethal dose 50 is exerted to label the virulence of infections into two classes, namely avirulent and virulent. A numerical representation of amino acids named ProtVec is applied to the eight-segments in a distributed manner to encode the biological sequences. After splittings and embeddings of influenza strains, the ensemble CNN is constructed as the base model on the influenza dataset of each segment, which serves as the VirPreNet's main part. Followed by a linear layer, the initial predictive outcomes are integrated and assigned with different weights for the final prediction. The experimental results on the collected influenza dataset indicate that VirPreNet achieves state-of-the-art performance combining ProtVec with our proposed architecture. It outperforms baseline methods on the independent testing data. Moreover, our proposed model reveals the importance of PB2 and HA segments on the virulence prediction. We believe that our model may provide new insights into the investigation of influenza virulence. AVAILABILITY AND IMPLEMENTATION Codes and data to generate the VirPreNet are publicly available at https://github.com/Rayin-saber/VirPreNet. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Rui Yin
- School of Computer Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Zihan Luo
- School of Electronic Information and Communication, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Pei Zhuang
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Zhuoyi Lin
- School of Computer Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Chee Keong Kwoh
- School of Computer Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
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7
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Weis S, te Velthuis AJW. Influenza Virus RNA Synthesis and the Innate Immune Response. Viruses 2021; 13:v13050780. [PMID: 33924859 PMCID: PMC8146608 DOI: 10.3390/v13050780] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 04/25/2021] [Accepted: 04/25/2021] [Indexed: 12/25/2022] Open
Abstract
Infection with influenza A and B viruses results in a mild to severe respiratory tract infection. It is widely accepted that many factors affect the severity of influenza disease, including viral replication, host adaptation, innate immune signalling, pre-existing immunity, and secondary infections. In this review, we will focus on the interplay between influenza virus RNA synthesis and the detection of influenza virus RNA by our innate immune system. Specifically, we will discuss the generation of various RNA species, host pathogen receptors, and host shut-off. In addition, we will also address outstanding questions that currently limit our knowledge of influenza virus replication and host adaption. Understanding the molecular mechanisms underlying these factors is essential for assessing the pandemic potential of future influenza virus outbreaks.
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8
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Gopal V, Nilsson-Payant BE, French H, Siegers JY, Yung WS, Hardwick M, Te Velthuis AJW. Zinc-embedded fabrics inactivate SARS-CoV-2 and influenza A virus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2021. [PMID: 33173872 PMCID: PMC7654868 DOI: 10.1101/2020.11.02.365833] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Infections with respiratory viruses can spread via liquid droplets and aerosols, and cause diseases such as influenza and COVID-19. Face masks and other personal protective equipment (PPE) can act as barriers that prevent the spread of respiratory droplets containing these viruses. However, influenza A viruses and coronaviruses are stable for hours on various materials, which makes frequent and correct disposal of these PPE important. Metal ions embedded into PPE may inactivate respiratory viruses, but confounding factors such as absorption of viruses make measuring and optimizing the inactivation characteristics difficult. Here we used polyamide 6.6 (PA66) fibers that had zinc ions embedded during the polymerisation process and systematically investigated if these fibers can absorb and inactivate pandemic SARS-CoV-2 and influenza A virus H1N1. We find that these viruses are readily absorbed by PA66 fabrics and inactivated by zinc ions embedded into this fabric. The inactivation rate (pfu·gram−1·min−1) exceeds the number of active virus particles expelled by a cough and supports a wide range of viral loads. Moreover, we found that the zinc content and the virus inactivating property of the fabric remain stable over 50 standardized washes. Overall, these results provide new insight into the development of “pathogen-free” PPE and better protection against RNA virus spread.
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Affiliation(s)
- Vikram Gopal
- Ascend Performance Materials, 1010 Travis Street, Suite 900, Houston, TX 77002, USA
| | | | - Hollie French
- Division of Virology, Department of Pathology, Addenbrooke's Hospital, University of Cambridge, Hills Road, CB2 2QQ, United Kingdom
| | - Jurre Y Siegers
- Department of Viroscience, Erasmus University Medical Centre, Rotterdam, the Netherlands
| | - Wai-Shing Yung
- Ascend Performance Materials, 1010 Travis Street, Suite 900, Houston, TX 77002, USA
| | - Matthew Hardwick
- ResInnova Laboratories, 8807 Colesville Rd, 3rd Floor, Silver Spring, MD 20910, USA
| | - Aartjan J W Te Velthuis
- Division of Virology, Department of Pathology, Addenbrooke's Hospital, University of Cambridge, Hills Road, CB2 2QQ, United Kingdom
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9
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Uehara T, Hayden FG, Kawaguchi K, Omoto S, Hurt AC, De Jong MD, Hirotsu N, Sugaya N, Lee N, Baba K, Shishido T, Tsuchiya K, Portsmouth S, Kida H. Treatment-Emergent Influenza Variant Viruses With Reduced Baloxavir Susceptibility: Impact on Clinical and Virologic Outcomes in Uncomplicated Influenza. J Infect Dis 2019; 221:346-355. [DOI: 10.1093/infdis/jiz244] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Accepted: 05/09/2019] [Indexed: 02/07/2023] Open
Abstract
Abstract
Background
Single-dose baloxavir rapidly reduces influenza virus titers and symptoms in patients with uncomplicated influenza, but viruses with reduced in vitro susceptibility due to amino acid substitutions at position 38 of polymerase acidic protein (PA/I38X) sometimes emerge.
Methods
We evaluated the kinetics, risk factors, and effects on clinical and virologic outcomes of emergence of PA/I38X-substituted viruses.
Results
Viruses containing PA/I38X substitutions were identified 3–9 days after baloxavir treatment in 9.7% (36/370) of patients, of whom 85.3% had transient virus titer rises. Median time to sustained cessation of infectious virus detection was 192, 48, and 96 hours in the baloxavir recipients with PA/I38X-substituted viruses, without PA/I38X-substituted viruses, and placebo recipients, respectively. The corresponding median times to alleviation of symptoms were 63.1, 51.0, and 80.2 hours, respectively. After day 5, symptom increases occurred in 11.5%, 8.0%, and 13.0%, respectively, and in 8.9% of oseltamivir recipients. Variant virus emergence was associated with lower baseline neutralizing antibody titers.
Conclusions
The emergence of viruses with PA/I38X substitutions following baloxavir treatment was associated with transient rises in infectious virus titers, prolongation of virus detectability, initial delay in symptom alleviation, and uncommonly with symptom rebound. The potential transmissibility of PA/I38X-substituted viruses requires careful study.
Clinical Trial Registration
NCT02954354.
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Affiliation(s)
| | | | | | | | - Aeron C Hurt
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria, Australia
| | - Menno D De Jong
- Department of Medical Microbiology, Academic Medical Center, University of Amsterdam, the Netherlands
| | | | - Norio Sugaya
- Department of Pediatrics, Keiyu Hospital, Yokohama, Japan
| | - Nelson Lee
- Division of Infectious Diseases, Department of Medicine, University of Alberta, Edmonton, Canada
| | | | | | | | | | - Hiroshi Kida
- Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan
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10
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Dou D, Revol R, Östbye H, Wang H, Daniels R. Influenza A Virus Cell Entry, Replication, Virion Assembly and Movement. Front Immunol 2018; 9:1581. [PMID: 30079062 PMCID: PMC6062596 DOI: 10.3389/fimmu.2018.01581] [Citation(s) in RCA: 289] [Impact Index Per Article: 48.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 06/26/2018] [Indexed: 12/20/2022] Open
Abstract
Influenza viruses replicate within the nucleus of the host cell. This uncommon RNA virus trait provides influenza with the advantage of access to the nuclear machinery during replication. However, it also increases the complexity of the intracellular trafficking that is required for the viral components to establish a productive infection. The segmentation of the influenza genome makes these additional trafficking requirements especially challenging, as each viral RNA (vRNA) gene segment must navigate the network of cellular membrane barriers during the processes of entry and assembly. To accomplish this goal, influenza A viruses (IAVs) utilize a combination of viral and cellular mechanisms to coordinate the transport of their proteins and the eight vRNA gene segments in and out of the cell. The aim of this review is to present the current mechanistic understanding for how IAVs facilitate cell entry, replication, virion assembly, and intercellular movement, in an effort to highlight some of the unanswered questions regarding the coordination of the IAV infection process.
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Affiliation(s)
- Dan Dou
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Rebecca Revol
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Henrik Östbye
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Hao Wang
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Robert Daniels
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
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11
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Mapping the Resistance Potential of Influenza's H + Channel against an Antiviral Blocker. J Mol Biol 2016; 428:4209-4217. [PMID: 27524470 DOI: 10.1016/j.jmb.2016.08.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 08/02/2016] [Accepted: 08/06/2016] [Indexed: 01/20/2023]
Abstract
The development of drug resistance has long plagued our efforts to curtail viral infections in general and influenza in particular. The problem is particularly challenging since the exact mode of resistance may be difficult to predict, without waiting for untreatable strains to evolve. Herein, a different approach is taken. Using a novel genetic screen, we map the resistance options of influenza's M2 channel against its aminoadamantane antiviral inhibitors. In the process, we could identify clinically known resistant mutations in a completely unbiased manner. Additionally, novel mutations were obtained, which, while known to exist in circulating viruses, were not previously classified as drug resistant. Finally, we demonstrated the approach against an anti-influenza drug that has not seen clinical use, identifying several resistance mutations in the process. In conclusion, we present and employ a method to predict the resistance options of influenza's M2 channel to antiviral agents ahead of clinical use and without medical hazard.
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12
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van Hemert F, van der Kuyl AC, Berkhout B. Impact of the biased nucleotide composition of viral RNA genomes on RNA structure and codon usage. J Gen Virol 2016; 97:2608-2619. [PMID: 27519195 DOI: 10.1099/jgv.0.000579] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We are interested in the influence of nucleotide composition on the fundamental characteristics of the virus RNA genome. Most RNA viruses have genomes with a distinct nucleotide composition, e.g. ranging from minimally 12.9 % to maximally 40.3 % (C- and U-count, respectively, in coronavirus HKU). We present a global analysis of diverse virus types, including plus-strand, minus-strand and double-strand RNA viruses, for the impact of this nucleotide preference on the predicted structure of the RNA genome that is packaged in virion particles and on the codon usage in the viral open reading frames. Several virus-specific features will be described, but also some general conclusions were drawn. Without exception, the virus-specific nucleotide bias was enriched in the unpaired, single-stranded regions of the RNA genome, thus creating an even more striking virus-specific signature. We present a simple mechanism that is based on elementary aspects of RNA structure folding to explain this general trend. In general, the nucleotide bias was the major determinant of the virus-specific codon usages, thus limiting a role for codon selection and translational control. We will discuss molecular and evolutionary scenarios that may be responsible for the diverse nucleotide biases of RNA viruses.
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Affiliation(s)
- Formijn van Hemert
- Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Amsterdam 1105 AZ, The Netherlands
| | - Antoinette C van der Kuyl
- Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Amsterdam 1105 AZ, The Netherlands
| | - Ben Berkhout
- Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Amsterdam 1105 AZ, The Netherlands
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Affiliation(s)
- Daniel Marc
- a ISP, INRA, Université Tours , Nouzilly , France
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