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Calaor-Morin J, Arguelles VL, Foronda JL, Tan A, Lagamayo E, Dapat C, Lupisan S. Genotyping of respiratory syncytial virus among influenza-like illness and severe acute respiratory infection cases of children in the Philippines from 2006 to 2016. Influenza Other Respir Viruses 2022; 16:942-951. [PMID: 35582932 PMCID: PMC9343341 DOI: 10.1111/irv.12986] [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: 12/05/2021] [Revised: 03/14/2022] [Accepted: 03/15/2022] [Indexed: 11/29/2022] Open
Abstract
Objective Respiratory syncytial virus (RSV) is a leading cause of severe lower respiratory infection, and therefore, a major threat to global health. This study determined the epidemiological and molecular characteristics of RSV among cases of influenza‐like illness (ILI) and severe acute respiratory infection (SARI) among children in the Philippines. Method The study included archived nasopharyngeal swab and oropharyngeal swab samples collected from patients under the age of five who are presented with ILI or SARI for the period of 2006–2016. Swabs were examined for RSV subgroup by multiplex real‐time qRT‐PCR. Partial genome sequencing and phylogenetic analyses of the second hypervariable region (HVR) of the G gene were used to determine the genotype of RSV isolates. Results A total of 1036 representative samples from all sites were selected and tested. Of these samples, 122 were RSV‐positive at 11.8% prevalence rate, and 58.2% (71/122) were classified as RSV‐A. Six genotypes were identified, which include NA1 (27/122, 22.1%), ON1 (5/122, 4.1%), GA2 (1/122, 0.8%), and GA5 (1/122, 0.8%) for RSV‐A; and BA2 (13/122, 10.7%) and BA9 (1/122, 0.8%) for RSV‐B. Most RSV‐related cases were significantly associated with clinical characteristics such as runny nose (88.1% RSV vs. 11.9% non‐RSV: p value = 0.021), pneumonia (80.6% RSV vs. 19.4% non‐RSV; p value = 0.015), and bronchitis (71.7% RSV vs. 28.3% non‐RSV; p value < 0.001). Increased RSV‐related cases were observed among children below 24 months old. Conclusion The RSV trend and genetic variability in the Philippines resembles a similar pattern of transmission globally.
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Affiliation(s)
- Jonjee Calaor-Morin
- Department of Virology, Research Institute for Tropical Medicine, Muntinlupa, Philippines.,Graduate School, University of Santo Tomas, Manila, Philippines
| | - Vina Lea Arguelles
- Department of Virology, Research Institute for Tropical Medicine, Muntinlupa, Philippines
| | - Janiza Lianne Foronda
- Department of Virology, Research Institute for Tropical Medicine, Muntinlupa, Philippines
| | - Alvin Tan
- Department of Epidemiology and Biostatistics, Research Institute for Tropical Medicine, Philippines
| | - Evelina Lagamayo
- Department of Medicine, University of Santo Tomas, Manila, Philippines
| | - Clyde Dapat
- RITM-Tohoku Collaborating Research Center on Emerging and Re-emerging Infectious Diseases, Muntinlupa, Philippines
| | - Socorro Lupisan
- Department of Virology, Research Institute for Tropical Medicine, Muntinlupa, Philippines
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Efstathiou C, Abidi SH, Harker J, Stevenson NJ. Revisiting respiratory syncytial virus's interaction with host immunity, towards novel therapeutics. Cell Mol Life Sci 2020; 77:5045-5058. [PMID: 32556372 PMCID: PMC7298439 DOI: 10.1007/s00018-020-03557-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 05/18/2020] [Accepted: 05/20/2020] [Indexed: 12/24/2022]
Abstract
Every year there are > 33 million cases of Respiratory Syncytial Virus (RSV)-related respiratory infection in children under the age of five, making RSV the leading cause of lower respiratory tract infection (LRTI) in infants. RSV is a global infection, but 99% of related mortality is in low/middle-income countries. Unbelievably, 62 years after its identification, there remains no effective treatment nor vaccine for this deadly virus, leaving infants, elderly and immunocompromised patients at high risk. The success of all pathogens depends on their ability to evade and modulate the host immune response. RSV has a complex and intricate relationship with our immune systems, but a clearer understanding of these interactions is essential in the development of effective medicines. Therefore, in a bid to update and focus our research community's understanding of RSV's interaction with immune defences, this review aims to discuss how our current knowledgebase could be used to combat this global viral threat.
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Affiliation(s)
- C Efstathiou
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - S H Abidi
- Department of Biological and Biomedical Sciences, Aga Khan University, Karachi, Pakistan
| | - J Harker
- Inflammation, Repair and Development Section, National Heart and Lung Institute, Imperial College London, South Kensington, London, UK
| | - N J Stevenson
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland.
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Aggarwal M, Plemper RK. Structural Insight into Paramyxovirus and Pneumovirus Entry Inhibition. Viruses 2020; 12:E342. [PMID: 32245118 PMCID: PMC7150754 DOI: 10.3390/v12030342] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Revised: 03/17/2020] [Accepted: 03/18/2020] [Indexed: 01/04/2023] Open
Abstract
Paramyxoviruses and pneumoviruses infect cells through fusion (F) protein-mediated merger of the viral envelope with target membranes. Members of these families include a range of major human and animal pathogens, such as respiratory syncytial virus (RSV), measles virus (MeV), human parainfluenza viruses (HPIVs), and highly pathogenic Nipah virus (NiV). High-resolution F protein structures in both the metastable pre- and the postfusion conformation have been solved for several members of the families and a number of F-targeting entry inhibitors have progressed to advanced development or clinical testing. However, small-molecule RSV entry inhibitors have overall disappointed in clinical trials and viral resistance developed rapidly in experimental settings and patients, raising the question of whether the available structural information may provide a path to counteract viral escape through proactive inhibitor engineering. This article will summarize current mechanistic insight into F-mediated membrane fusion and examine the contribution of structural information to the development of small-molecule F inhibitors. Implications are outlined for future drug target selection and rational drug engineering strategies.
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Affiliation(s)
| | - Richard K Plemper
- Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA;
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Discovery of methylsulfonyl indazoles as potent and orally active respiratory syncytial Virus(RSV) fusion inhibitors. Eur J Med Chem 2017; 138:1147-1157. [DOI: 10.1016/j.ejmech.2017.07.032] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2017] [Revised: 07/17/2017] [Accepted: 07/18/2017] [Indexed: 11/22/2022]
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Weisshaar M, Cox R, Morehouse Z, Kyasa SK, Yan D, Oberacker P, Mao S, Golden JE, Lowen AC, Natchus MG, Plemper RK. Identification and Characterization of Influenza Virus Entry Inhibitors through Dual Myxovirus High-Throughput Screening. J Virol 2016; 90:7368-7387. [PMID: 27252534 PMCID: PMC4984618 DOI: 10.1128/jvi.00898-16] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2016] [Accepted: 05/26/2016] [Indexed: 12/31/2022] Open
Abstract
UNLABELLED Influenza A virus (IAV) infections cause major morbidity and mortality, generating an urgent need for novel antiviral therapeutics. We recently established a dual myxovirus high-throughput screening protocol that combines a fully replication-competent IAV-WSN strain and a respiratory syncytial virus reporter strain for the simultaneous identification of IAV-specific, paramyxovirus-specific, and broad-spectrum inhibitors. In the present study, this protocol was applied to a screening campaign to assess a diverse chemical library with over 142,000 entries. Focusing on IAV-specific hits, we obtained a hit rate of 0.03% after cytotoxicity testing and counterscreening. Three chemically distinct hit classes with nanomolar potency and favorable cytotoxicity profiles were selected. Time-of-addition, minigenome, and viral entry studies demonstrated that these classes block hemagglutinin (HA)-mediated membrane fusion. Antiviral activity extends to an isolate from the 2009 pandemic and, in one case, another group 1 subtype. Target identification through biolayer interferometry confirmed binding of all hit compounds to HA. Resistance profiling revealed two distinct escape mechanisms: primary resistance, associated with reduced compound binding, and secondary resistance, associated with unaltered binding. Secondary resistance was mediated, unusually, through two different pairs of cooperative mutations, each combining a mutation eliminating the membrane-proximal stalk N-glycan with a membrane-distal change in HA1 or HA2. Chemical synthesis of an analog library combined with in silico docking extracted a docking pose for the hit classes. Chemical interrogation spotlights IAV HA as a major druggable target for small-molecule inhibition. Our study identifies novel chemical scaffolds with high developmental potential, outlines diverse routes of IAV escape from entry inhibition, and establishes a path toward structure-aided lead development. IMPORTANCE This study is one of the first to apply a fully replication-competent third-generation IAV reporter strain to a large-scale high-throughput screen (HTS) drug discovery campaign, allowing multicycle infection and screening in physiologically relevant human respiratory cells. A large number of potential druggable targets was thus chemically interrogated, but mechanistic characterization, positive target identification, and resistance profiling demonstrated that three chemically promising and structurally distinct hit classes selected for further analysis all block HA-mediated membrane fusion. Viral escape from inhibition could be achieved through primary and secondary resistance mechanisms. In silico docking predicted compound binding to a microdomain located at the membrane-distal site of the prefusion HA stalk that was also previously suggested as a target site for chemically unrelated HA inhibitors. This study identifies an unexpected chemodominance of the HA stalk microdomain for small-molecule inhibitors in IAV inhibitor screening campaigns and highlights a novel mechanism of cooperative resistance to IAV entry blockers.
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Affiliation(s)
- Marco Weisshaar
- Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, USA
| | - Robert Cox
- Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, USA
| | - Zachary Morehouse
- Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, USA
| | - Shiva K Kyasa
- Emory Institute for Drug Development, Emory University, Atlanta, GA, USA
| | - Dan Yan
- Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, USA
| | - Phil Oberacker
- Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, USA
| | - Shuli Mao
- Emory Institute for Drug Development, Emory University, Atlanta, GA, USA
| | - Jennifer E Golden
- Department of Pharmacology, University of Wisconsin, Madison, WI, USA
| | - Anice C Lowen
- Department of Microbiology & Immunology, Emory University School of Medicine, Atlanta, GA, USA
| | - Michael G Natchus
- Emory Institute for Drug Development, Emory University, Atlanta, GA, USA
| | - Richard K Plemper
- Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, USA
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Yan D, Weisshaar M, Lamb K, Chung HK, Lin MZ, Plemper RK. Replication-Competent Influenza Virus and Respiratory Syncytial Virus Luciferase Reporter Strains Engineered for Co-Infections Identify Antiviral Compounds in Combination Screens. Biochemistry 2015; 54:5589-604. [PMID: 26307636 PMCID: PMC4719150 DOI: 10.1021/acs.biochem.5b00623] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Myxoviruses such as influenza A virus (IAV) and respiratory syncytial virus (RSV) are major human pathogens, mandating the development of novel therapeutics. To establish a high-throughput screening protocol for the simultaneous identification of pathogen- and host-targeted hit candidates against either pathogen or both, we have attempted co-infection of cells with IAV and RSV. However, viral replication kinetics were incompatible, RSV signal window was low, and an IAV-driven minireplicon reporter assay used in initial screens narrowed the host cell range and restricted the assay to single-cycle infections. To overcome these limitations, we developed an RSV strain carrying firefly luciferase fused to an innovative universal small-molecule assisted shut-off domain, which boosted assay signal window, and a hyperactive fusion protein that synchronized IAV and RSV reporter expression kinetics and suppressed the identification of RSV entry inhibitors sensitive to a recently reported RSV pan-resistance mechanism. Combined with a replication-competent recombinant IAV strain harboring nanoluciferase, the assay performed well on a human respiratory cell line and supports multicycle infections. Miniaturized to 384-well format, the protocol was validated through screening of a set of the National Institutes of Health Clinical Collection (NCC) in quadruplicate. These test screens demonstrated favorable assay parameters and reproducibility. Application to a LOPAC library of bioactive compounds in a proof-of-concept campaign detected licensed antimyxovirus therapeutics, ribavirin and the neuraminidase inhibitor zanamivir, and identified two unexpected RSV-specific hit candidates, Fenretinide and the opioid receptor antagonist BNTX-7. Hits were evaluated in direct and orthogonal dose-response counterscreens using a standard recRSV reporter strain expressing Renilla luciferase.
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Affiliation(s)
- Dan Yan
- Institute for Biomedical Sciences, Georgia State University, Atlanta, GA
| | - Marco Weisshaar
- Institute for Biomedical Sciences, Georgia State University, Atlanta, GA
| | - Kristen Lamb
- Institute for Biomedical Sciences, Georgia State University, Atlanta, GA
| | | | - Michael Z Lin
- Department of Bioengineering, Stanford University, Stanford, CA
- Department of Pediatrics, Stanford University, Stanford, CA
| | - Richard K Plemper
- Institute for Biomedical Sciences, Georgia State University, Atlanta, GA
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