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Arduini A, Laprise F, Liang C. SARS-CoV-2 ORF8: A Rapidly Evolving Immune and Viral Modulator in COVID-19. Viruses 2023; 15:871. [PMID: 37112851 PMCID: PMC10141009 DOI: 10.3390/v15040871] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 03/26/2023] [Accepted: 03/27/2023] [Indexed: 03/31/2023] Open
Abstract
The COVID-19 pandemic has resulted in upwards of 6.8 million deaths over the past three years, and the frequent emergence of variants continues to strain global health. Although vaccines have greatly helped mitigate disease severity, SARS-CoV-2 is likely to remain endemic, making it critical to understand its viral mechanisms contributing to pathogenesis and discover new antiviral therapeutics. To efficiently infect, this virus uses a diverse set of strategies to evade host immunity, accounting for its high pathogenicity and rapid spread throughout the COVID-19 pandemic. Behind some of these critical host evasion strategies is the accessory protein Open Reading Frame 8 (ORF8), which has gained recognition in SARS-CoV-2 pathogenesis due to its hypervariability, secretory property, and unique structure. This review discusses the current knowledge on SARS-CoV-2 ORF8 and proposes actualized functional models describing its pivotal roles in both viral replication and immune evasion. A better understanding of ORF8's interactions with host and viral factors is expected to reveal essential pathogenic strategies utilized by SARS-CoV-2 and inspire the development of novel therapeutics to improve COVID-19 disease outcomes.
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Affiliation(s)
- Ariana Arduini
- Lady Davis Institute, Jewish General Hospital, Montreal, QC H3T 1E2, Canada; (A.A.); (F.L.)
- Department of Medicine, McGill University, Montreal, QC H3G 2M1, Canada
| | - Frederique Laprise
- Lady Davis Institute, Jewish General Hospital, Montreal, QC H3T 1E2, Canada; (A.A.); (F.L.)
- Department of Microbiology and Immunology, McGill University, Montreal, QC H3A 2B4, Canada
| | - Chen Liang
- Lady Davis Institute, Jewish General Hospital, Montreal, QC H3T 1E2, Canada; (A.A.); (F.L.)
- Department of Medicine, McGill University, Montreal, QC H3G 2M1, Canada
- Department of Microbiology and Immunology, McGill University, Montreal, QC H3A 2B4, Canada
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Podury S, Kwon S, Javed U, Farooqi MS, Li Y, Liu M, Grunig G, Nolan A. Severe Acute Respiratory Syndrome and Particulate Matter Exposure: A Systematic Review. Life (Basel) 2023; 13:538. [PMID: 36836898 PMCID: PMC9962044 DOI: 10.3390/life13020538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 01/30/2023] [Accepted: 02/03/2023] [Indexed: 02/17/2023] Open
Abstract
BACKGROUND Particulate matter (PM) exposure is responsible for seven million deaths annually and has been implicated in the pathogenesis of respiratory infections such as severe acute respiratory syndrome (SARS). Understanding modifiable risk factors of high mortality, resource burdensome C19 and exposure risks such as PM is key to mitigating their devastating effects. This systematic review focuses on the literature available, identifying the spatial and temporal variation in the role of quantified PM exposure in SARS disease outcome and planning our future experimental studies. METHODS The systematic review utilized keywords adhered to the PRISMA guidelines. We included original human research studies in English. RESULTS Initial search yielded N = 906, application of eligibility criteria yielded N = 46. Upon analysis of risk of bias N = 41 demonstrated high risk. Studies found a positive association between elevated PM2.5, PM10 and SARS-related outcomes. A geographic and temporal variation in both PM and C19's role was observed. CONCLUSION C19 is a high mortality and resource intensive disease which devastated the globe. PM exposure is also a global health crisis. Our systematic review focuses on the intersection of this impactful disease-exposure dyad and understanding the role of PM is important in the development of interventions to prevent future spread of viral infections.
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Affiliation(s)
- Sanjiti Podury
- Department of Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, New York University Grossman School of Medicine (NYUGSoM), New York, NY 10016, USA; (S.P.); (S.K.); (U.J.); (M.S.F.)
| | - Sophia Kwon
- Department of Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, New York University Grossman School of Medicine (NYUGSoM), New York, NY 10016, USA; (S.P.); (S.K.); (U.J.); (M.S.F.)
| | - Urooj Javed
- Department of Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, New York University Grossman School of Medicine (NYUGSoM), New York, NY 10016, USA; (S.P.); (S.K.); (U.J.); (M.S.F.)
| | - Muhammad S. Farooqi
- Department of Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, New York University Grossman School of Medicine (NYUGSoM), New York, NY 10016, USA; (S.P.); (S.K.); (U.J.); (M.S.F.)
| | - Yiwei Li
- Department of Population Health, Division of Biostatistics, New York University Grossman School of Medicine (NYUGSoM), New York, NY 10016, USA; (Y.L.); (M.L.)
| | - Mengling Liu
- Department of Population Health, Division of Biostatistics, New York University Grossman School of Medicine (NYUGSoM), New York, NY 10016, USA; (Y.L.); (M.L.)
- Department of Medicine, Division of Environmental Medicine, New York University Grossman School of Medicine (NYUGSoM), New York, NY 10016, USA;
| | - Gabriele Grunig
- Department of Medicine, Division of Environmental Medicine, New York University Grossman School of Medicine (NYUGSoM), New York, NY 10016, USA;
| | - Anna Nolan
- Department of Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, New York University Grossman School of Medicine (NYUGSoM), New York, NY 10016, USA; (S.P.); (S.K.); (U.J.); (M.S.F.)
- Department of Medicine, Division of Environmental Medicine, New York University Grossman School of Medicine (NYUGSoM), New York, NY 10016, USA;
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Quéromès G, Destras G, Bal A, Regue H, Burfin G, Brun S, Fanget R, Morfin F, Valette M, Trouillet-Assant S, Lina B, Frobert E, Josset L. Characterization of SARS-CoV-2 ORF6 deletion variants detected in a nosocomial cluster during routine genomic surveillance, Lyon, France. Emerg Microbes Infect 2021; 10:167-177. [PMID: 33399033 PMCID: PMC7850418 DOI: 10.1080/22221751.2021.1872351] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 12/10/2020] [Accepted: 12/30/2020] [Indexed: 12/21/2022]
Abstract
During routine molecular surveillance of SARS-CoV-2 performed at the National Reference Center of Respiratory Viruses (Lyon, France) (n = 229 sequences collected February-April 2020), two frameshifting deletions were detected in the open reading frame 6, at the same position (27267). While a 26-nucleotide deletion variant (D26) was only found in one nasopharyngeal sample in March 2020, the 34-nucleotide deletion (D34) was found within a single geriatric hospital unit in 5/9 patients and one health care worker in April 2020. Phylogeny analysis strongly suggested a nosocomial transmission of D34, with potential fecal transmission, as also identified in a stool sample. No difference in disease severity was observed between patients hospitalized in the geriatric unit infected with WT or D34. In vitro D26 and D34 characterization revealed comparable replication kinetics with the wild-type (WT), but differential host immune responses. While interferon-stimulated genes were similarly upregulated after infection with WT and ORF6 variants, the latter specifically induced overexpression of 9 genes coding for inflammatory cytokines in the NF-kB pathway, including CCL2/MCP1, PTX3, and TNFα, for which high plasma levels have been associated with severe COVID-19. Our findings emphasize the need to monitor the occurrence of ORF6 deletions and assess their impact on the host immune response.
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Affiliation(s)
- Grégory Quéromès
- CIRI, Centre International de Recherche en Infectiologie, Team VirPatH, Lyon, Fracne
| | - Grégory Destras
- CIRI, Centre International de Recherche en Infectiologie, Team VirPatH, Lyon, Fracne
- Laboratoire de Virologie, Institut des Agents Infectieux (IAI), Hospices Civils de Lyon, Lyon, France
| | - Antonin Bal
- CIRI, Centre International de Recherche en Infectiologie, Team VirPatH, Lyon, Fracne
- Laboratoire de Virologie, Institut des Agents Infectieux (IAI), Hospices Civils de Lyon, Lyon, France
| | - Hadrien Regue
- Laboratoire de Virologie, Institut des Agents Infectieux (IAI), Hospices Civils de Lyon, Lyon, France
| | - Gwendolyne Burfin
- Laboratoire de Virologie, Institut des Agents Infectieux (IAI), Hospices Civils de Lyon, Lyon, France
- Centre National de Référence des virus des infections respiratoires, Lyon, Fracne
| | - Solenne Brun
- Laboratoire de Virologie, Institut des Agents Infectieux (IAI), Hospices Civils de Lyon, Lyon, France
- Centre National de Référence des virus des infections respiratoires, Lyon, Fracne
| | - Rémi Fanget
- Laboratoire de Virologie, Institut des Agents Infectieux (IAI), Hospices Civils de Lyon, Lyon, France
- Centre National de Référence des virus des infections respiratoires, Lyon, Fracne
| | - Florence Morfin
- CIRI, Centre International de Recherche en Infectiologie, Team VirPatH, Lyon, Fracne
- Laboratoire de Virologie, Institut des Agents Infectieux (IAI), Hospices Civils de Lyon, Lyon, France
| | - Martine Valette
- CIRI, Centre International de Recherche en Infectiologie, Team VirPatH, Lyon, Fracne
- Laboratoire de Virologie, Institut des Agents Infectieux (IAI), Hospices Civils de Lyon, Lyon, France
- Centre National de Référence des virus des infections respiratoires, Lyon, Fracne
| | | | - Bruno Lina
- CIRI, Centre International de Recherche en Infectiologie, Team VirPatH, Lyon, Fracne
- Laboratoire de Virologie, Institut des Agents Infectieux (IAI), Hospices Civils de Lyon, Lyon, France
- Centre National de Référence des virus des infections respiratoires, Lyon, Fracne
| | - Emilie Frobert
- CIRI, Centre International de Recherche en Infectiologie, Team VirPatH, Lyon, Fracne
- Laboratoire de Virologie, Institut des Agents Infectieux (IAI), Hospices Civils de Lyon, Lyon, France
| | - Laurence Josset
- CIRI, Centre International de Recherche en Infectiologie, Team VirPatH, Lyon, Fracne
- Laboratoire de Virologie, Institut des Agents Infectieux (IAI), Hospices Civils de Lyon, Lyon, France
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Interspecies Jumping of Bat Coronaviruses. Viruses 2021; 13:v13112188. [PMID: 34834994 PMCID: PMC8620431 DOI: 10.3390/v13112188] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 10/27/2021] [Accepted: 10/28/2021] [Indexed: 12/15/2022] Open
Abstract
In the last two decades, several coronavirus (CoV) interspecies jumping events have occurred between bats and other animals/humans, leading to major epidemics/pandemics and high fatalities. The SARS epidemic in 2002/2003 had a ~10% fatality. The discovery of SARS-related CoVs in horseshoe bats and civets and genomic studies have confirmed bat-to-civet-to-human transmission. The MERS epidemic that emerged in 2012 had a ~35% mortality, with dromedaries as the reservoir. Although CoVs with the same genome organization (e.g., Tylonycteris BatCoV HKU4 and Pipistrellus BatCoV HKU5) were also detected in bats, there is still a phylogenetic gap between these bat CoVs and MERS-CoV. In 2016, 10 years after the discovery of Rhinolophus BatCoV HKU2 in Chinese horseshoe bats, fatal swine disease outbreaks caused by this virus were reported in southern China. In late 2019, an outbreak of pneumonia emerged in Wuhan, China, and rapidly spread globally, leading to >4,000,000 fatalities so far. Although the genome of SARS-CoV-2 is highly similar to that of SARS-CoV, patient zero and the original source of the pandemic are still unknown. To protect humans from future public health threats, measures should be taken to monitor and reduce the chance of interspecies jumping events, either occurring naturally or through recombineering experiments.
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Reduced subgenomic RNA expression is a molecular indicator of asymptomatic SARS-CoV-2 infection. COMMUNICATIONS MEDICINE 2021; 1:33. [PMID: 35602196 PMCID: PMC9053197 DOI: 10.1038/s43856-021-00034-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 09/02/2021] [Indexed: 01/12/2023] Open
Abstract
Background It is estimated that up to 80% of infections caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are asymptomatic and asymptomatic patients can still effectively transmit the virus and cause disease. While much of the effort has been placed on decoding single nucleotide variation in SARS-CoV-2 genomes, considerably less is known about their transcript variation and any correlation with clinical severity in human hosts, as defined here by the presence or absence of symptoms. Methods To assess viral genomic signatures of disease severity, we conducted a systematic characterization of SARS-CoV-2 transcripts and genetic variants in 81 clinical specimens collected from symptomatic and asymptomatic individuals using multi-scale transcriptomic analyses including amplicon-seq, short-read metatranscriptome and long-read Iso-seq. Results Here we show a highly coordinated and consistent pattern of sgRNA expression from individuals with robust SARS-CoV-2 symptomatic infection and their expression is significantly repressed in the asymptomatic infections. We also observe widespread inter- and intra-patient variants in viral RNAs, known as quasispecies frequently found in many RNA viruses. We identify unique sets of deletions preferentially found primarily in symptomatic individuals, with many likely to confer changes in SARS-CoV-2 virulence and host responses. Moreover, these frequently occurring structural variants in SARS-CoV-2 genomes serve as a mechanism to further induce SARS-CoV-2 proteome complexity. Conclusions Our results indicate that differential sgRNA expression and structural mutational burden are highly correlated with the clinical severity of SARS-CoV-2 infection. Longitudinally monitoring sgRNA expression and structural diversity could further guide treatment responses, testing strategies, and vaccine development. Wong and Ngan et al. characterize the expression and structural variation of SARS-CoV-2 subgenomic RNAs (sgRNAs) in diagnostic specimens from symptomatic and asymptomatic COVID-19 patients. In a series of genomic and transcriptomic analyses, the authors observe reduced sgRNA expression and a distinct set of structural deletions in asymptomatic infections compared with symptomatic infections. Infection with SARS-CoV-2 can lead to symptoms of different severity, with some individuals remaining entirely asymptomatic but still responsible for much of the viral transmission. Here, we sought to identify markers of the severity of symptoms of SARS-CoV-2 infection, as defined by the presence or absence of symptoms. We used a combination of methods to study SARS-CoV-2 genes and their readouts, known as transcripts, in clinical samples from people with symptomatic and asymptomatic infections. We demonstrate that transcripts responsible for making viral proteins are seen at lower levels in asymptomatic infections. We also identify structural changes in the viral genes and transcripts that potentially influence the host’s response to the virus. Our study defines potential markers of symptom severity that may ultimately guide risk mitigation and testing strategies.
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Cloning of a Passage-Free SARS-CoV-2 Genome and Mutagenesis Using Red Recombination. Int J Mol Sci 2021; 22:ijms221910188. [PMID: 34638527 PMCID: PMC8507965 DOI: 10.3390/ijms221910188] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 09/17/2021] [Accepted: 09/17/2021] [Indexed: 11/16/2022] Open
Abstract
The ongoing pandemic coronavirus (CoV) disease 2019 (COVID-19) by severe acute respiratory syndrome CoV-2 (SARS-CoV-2) has already caused substantial morbidity, mortality, and economic devastation. Reverse genetic approaches to generate recombinant viruses are a powerful tool to characterize and understand newly emerging viruses. To contribute to the global efforts for countermeasures to control the spread of SARS-CoV-2, we developed a passage-free SARS-CoV-2 clone based on a bacterial artificial chromosome (BAC). Moreover, using a Lambda-based Red recombination, we successfully generated different reporter and marker viruses, which replicated similar to a clinical isolate in a cell culture. Moreover, we designed a full-length reporter virus encoding an additional artificial open reading frame with wild-type-like replication features. The virus-encoded reporters were successfully applied to ease antiviral testing in cell culture models. Furthermore, we designed a new marker virus encoding 3xFLAG-tagged nucleocapsid that allows the detection of incoming viral particles and, in combination with bio-orthogonal labeling for the visualization of viral RNA synthesis via click chemistry, the spatiotemporal tracking of viral replication on the single-cell level. In summary, by applying BAC-based Red recombination, we developed a powerful, reliable, and convenient platform that will facilitate studies answering numerous questions concerning the biology of SARS-CoV-2.
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Cotten M, Robertson DL, Phan MVT. Unique protein features of SARS-CoV-2 relative to other Sarbecoviruses. Virus Evol 2021; 7:veab067. [PMID: 34527286 PMCID: PMC8385934 DOI: 10.1093/ve/veab067] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Revised: 06/30/2021] [Accepted: 08/06/2021] [Indexed: 01/08/2023] Open
Abstract
Defining the unique properties of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) protein sequences has potential to explain the range of Coronavirus Disease 2019 severity. To achieve this we compared proteins encoded by all Sarbecoviruses using profile Hidden Markov Model similarities to identify protein features unique to SARS-CoV-2. Consistent with previous reports, a small set of bat- and pangolin-derived Sarbecoviruses show the greatest similarity to SARS-CoV-2 but are unlikely to be the direct source of SARS-CoV-2. Three proteins (nsp3, spike, and orf9) showed regions differing between the bat Sarbecoviruses and SARS-CoV-2 and indicate virus protein features that might have evolved to support human infection and/or transmission. Spike analysis identified all regions of the protein that have tolerated change and revealed that the current SARS-CoV-2 variants of concern have sampled only a fraction (∼31 per cent) of the possible spike domain changes which have occurred historically in Sarbecovirus evolution. This result emphasises the evolvability of these coronaviruses and the potential for further change in virus replication and transmission properties over the coming years.
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Affiliation(s)
- Matthew Cotten
- MRC/UVRI & LSHTM Uganda Research Unit, Plot 51-59 Nakiwogo Road, P.O Box 49, Entebbe, Uganda
- MRC-University of Glasgow Centre for Virus Research, Sir Michael Stoker Building, Garscube Campus, 464 Bearsden Road, Glasgow G61 1QH, UK
| | - David L Robertson
- MRC-University of Glasgow Centre for Virus Research, Sir Michael Stoker Building, Garscube Campus, 464 Bearsden Road, Glasgow G61 1QH, UK
| | - My V T Phan
- MRC/UVRI & LSHTM Uganda Research Unit, Plot 51-59 Nakiwogo Road, P.O Box 49, Entebbe, Uganda
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Gorkhali R, Koirala P, Rijal S, Mainali A, Baral A, Bhattarai HK. Structure and Function of Major SARS-CoV-2 and SARS-CoV Proteins. Bioinform Biol Insights 2021; 15:11779322211025876. [PMID: 34220199 PMCID: PMC8221690 DOI: 10.1177/11779322211025876] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 05/25/2021] [Indexed: 01/20/2023] Open
Abstract
SARS-CoV-2 virus, the causative agent of COVID-19 pandemic, has a genomic organization consisting of 16 nonstructural proteins (nsps), 4 structural proteins, and 9 accessory proteins. Relative of SARS-CoV-2, SARS-CoV, has genomic organization, which is very similar. In this article, the function and structure of the proteins of SARS-CoV-2 and SARS-CoV are described in great detail. The nsps are expressed as a single or two polyproteins, which are then cleaved into individual proteins using two proteases of the virus, a chymotrypsin-like protease and a papain-like protease. The released proteins serve as centers of virus replication and transcription. Some of these nsps modulate the host’s translation and immune systems, while others help the virus evade the host immune system. Some of the nsps help form replication-transcription complex at double-membrane vesicles. Others, including one RNA-dependent RNA polymerase and one exonuclease, help in the polymerization of newly synthesized RNA of the virus and help minimize the mutation rate by proofreading. After synthesis of the viral RNA, it gets capped. The capping consists of adding GMP and a methylation mark, called cap 0 and additionally adding a methyl group to the terminal ribose called cap1. Capping is accomplished with the help of a helicase, which also helps remove a phosphate, two methyltransferases, and a scaffolding factor. Among the structural proteins, S protein forms the receptor of the virus, which latches on the angiotensin-converting enzyme 2 receptor of the host and N protein binds and protects the genomic RNA of the virus. The accessory proteins found in these viruses are small proteins with immune modulatory roles. Besides functions of these proteins, solved X-ray and cryogenic electron microscopy structures related to the function of the proteins along with comparisons to other coronavirus homologs have been described in the article. Finally, the rate of mutation of SARS-CoV-2 residues of the proteome during the 2020 pandemic has been described. Some proteins are mutated more often than other proteins, but the significance of these mutation rates is not fully understood.
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Affiliation(s)
- Ritesh Gorkhali
- Department of Biotechnology, Kathmandu University, Dhulikhel, Nepal
| | | | - Sadikshya Rijal
- Department of Biotechnology, Kathmandu University, Dhulikhel, Nepal
| | - Ashmita Mainali
- Department of Biotechnology, Kathmandu University, Dhulikhel, Nepal
| | - Adesh Baral
- Department of Biotechnology, Kathmandu University, Dhulikhel, Nepal
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Nagaraja S, Jain D, Kesavardhana S. Inflammasome regulation in driving COVID-19 severity in humans and immune tolerance in bats. J Leukoc Biol 2021; 111:497-508. [PMID: 34057760 PMCID: PMC8242921 DOI: 10.1002/jlb.4covhr0221-093rr] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Coronaviruses (CoVs) are RNA viruses that cause human respiratory infections. Zoonotic transmission of the SARS‐CoV‐2 virus caused the recent COVID‐19 pandemic, which led to over 2 million deaths worldwide. Elevated inflammatory responses and cytotoxicity in the lungs are associated with COVID‐19 severity in SARS‐CoV‐2‐infected individuals. Bats, which host pathogenic CoVs, operate dampened inflammatory responses and show tolerance to these viruses with mild clinical symptoms. Delineating the mechanisms governing these host‐specific inflammatory responses is essential to understand host–virus interactions determining the outcome of pathogenic CoV infections. Here, we describe the essential role of inflammasome activation in determining COVID‐19 severity in humans and innate immune tolerance in bats that host several pathogenic CoVs. We further discuss mechanisms leading to inflammasome activation in human SARS‐CoV‐2 infection and how bats are molecularly adapted to suppress these inflammasome responses. We also report an analysis of functionally important residues of inflammasome components that provide new clues of bat strategies to suppress inflammasome signaling and innate immune responses. As spillover of bat viruses may cause the emergence of new human disease outbreaks, the inflammasome regulation in bats and humans likely provides specific strategies to combat the pathogenic CoV infections.
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Affiliation(s)
- Sahana Nagaraja
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, India
| | - Disha Jain
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, India
| | - Sannula Kesavardhana
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, India
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Huang K, Zhang Y, Hui X, Zhao Y, Gong W, Wang T, Zhang S, Yang Y, Deng F, Zhang Q, Chen X, Yang Y, Sun X, Chen H, Tao YJ, Zou Z, Jin M. Q493K and Q498H substitutions in Spike promote adaptation of SARS-CoV-2 in mice. EBioMedicine 2021; 67:103381. [PMID: 33993052 PMCID: PMC8118724 DOI: 10.1016/j.ebiom.2021.103381] [Citation(s) in RCA: 78] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 04/16/2021] [Accepted: 04/19/2021] [Indexed: 01/24/2023] Open
Abstract
Background An ideal animal model to study SARS-coronavirus 2 (SARS-CoV-2) pathogenesis and evaluate therapies and vaccines should reproduce SARS-CoV-2 infection and recapitulate lung disease like those seen in humans. The angiotensin-converting enzyme 2 (ACE2) is a functional receptor for SARS-CoV-2, but mice are resistant to the infection because their ACE2 is incompatible with the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein . Methods SARS-CoV-2 was passaged in BALB/c mice to obtain mouse-adapted virus strain. Complete genome deep sequencing of different generations of viruses was performed to characterize the dynamics of the adaptive mutations in SARS-CoV-2. Indirect immunofluorescence analysis and Biolayer interferometry experiments determined the binding affinity of mouse-adapted SARS-CoV-2 WBP-1 RBD to mouse ACE2 and human ACE2. Finally, we tested whether TLR7/8 agonist Resiquimod (R848) could also inhibit the replication of WBP-1 in the mouse model. Findings The mouse-adapted strain WBP-1 showed increased infectivity in BALB/c mice and led to severe interstitial pneumonia. We characterized the dynamics of the adaptive mutations in SARS-CoV-2 and demonstrated that Q493K and Q498H in RBD significantly increased its binding affinity towards mouse ACE2. Additionally, the study tentatively found that the TLR7/8 agonist Resiquimod was able to protect mice against WBP-1 challenge. Therefore, this mouse-adapted strain is a useful tool to investigate COVID-19 and develop new therapies. Interpretation We found for the first time that the Q493K and Q498H mutations in the RBD of WBP-1 enhanced its interactive affinities with mACE2. The mouse-adapted SARS-CoV-2 provides a valuable tool for the evaluation of novel antiviral and vaccine strategies. This study also tentatively verified the antiviral activity of TLR7/8 agonist Resiquimod against SARS-CoV-2 in vitro and in vivo. Funding This research was funded by the National Key Research and Development Program of China (2020YFC0845600) and Emergency Science and Technology Project of Hubei Province (2020FCA046) and Robert A. Welch Foundation (C-1565).
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Affiliation(s)
- Kun Huang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China; Key Laboratory of development of veterinary diagnostic products, Ministry of Agriculture, Wuhan, 430070, PR China
| | - Yufei Zhang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China; Key Laboratory of development of veterinary diagnostic products, Ministry of Agriculture, Wuhan, 430070, PR China
| | - Xianfeng Hui
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China; Key Laboratory of development of veterinary diagnostic products, Ministry of Agriculture, Wuhan, 430070, PR China
| | - Ya Zhao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China; Key Laboratory of development of veterinary diagnostic products, Ministry of Agriculture, Wuhan, 430070, PR China
| | - Wenxiao Gong
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China; Key Laboratory of development of veterinary diagnostic products, Ministry of Agriculture, Wuhan, 430070, PR China
| | - Ting Wang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China; Key Laboratory of development of veterinary diagnostic products, Ministry of Agriculture, Wuhan, 430070, PR China
| | - Shaoran Zhang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Yong Yang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China; Key Laboratory of development of veterinary diagnostic products, Ministry of Agriculture, Wuhan, 430070, PR China
| | - Fei Deng
- State Key Laboratory of Virology and National Virus Resource Center, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, PR China
| | - Qiang Zhang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China; Key Laboratory of development of veterinary diagnostic products, Ministry of Agriculture, Wuhan, 430070, PR China
| | - Xi Chen
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China
| | - Ying Yang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China; Key Laboratory of development of veterinary diagnostic products, Ministry of Agriculture, Wuhan, 430070, PR China
| | - Xiaomei Sun
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China; Key Laboratory of development of veterinary diagnostic products, Ministry of Agriculture, Wuhan, 430070, PR China
| | - Huanchun Chen
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China
| | - Yizhi J Tao
- Department of BioSciences, Rice University, Houston, TX 77005, USA
| | - Zhong Zou
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China; Key Laboratory of development of veterinary diagnostic products, Ministry of Agriculture, Wuhan, 430070, PR China.
| | - Meilin Jin
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China; Key Laboratory of development of veterinary diagnostic products, Ministry of Agriculture, Wuhan, 430070, PR China.
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11
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Lau BT, Pavlichin D, Hooker AC, Almeda A, Shin G, Chen J, Sahoo MK, Huang CH, Pinsky BA, Lee HJ, Ji HP. Profiling SARS-CoV-2 mutation fingerprints that range from the viral pangenome to individual infection quasispecies. Genome Med 2021; 13:62. [PMID: 33875001 PMCID: PMC8054698 DOI: 10.1186/s13073-021-00882-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 03/31/2021] [Indexed: 12/14/2022] Open
Abstract
Background The genome of SARS-CoV-2 is susceptible to mutations during viral replication due to the errors generated by RNA-dependent RNA polymerases. These mutations enable the SARS-CoV-2 to evolve into new strains. Viral quasispecies emerge from de novo mutations that occur in individual patients. In combination, these sets of viral mutations provide distinct genetic fingerprints that reveal the patterns of transmission and have utility in contact tracing. Methods Leveraging thousands of sequenced SARS-CoV-2 genomes, we performed a viral pangenome analysis to identify conserved genomic sequences. We used a rapid and highly efficient computational approach that relies on k-mers, short tracts of sequence, instead of conventional sequence alignment. Using this method, we annotated viral mutation signatures that were associated with specific strains. Based on these highly conserved viral sequences, we developed a rapid and highly scalable targeted sequencing assay to identify mutations, detect quasispecies variants, and identify mutation signatures from patients. These results were compared to the pangenome genetic fingerprints. Results We built a k-mer index for thousands of SARS-CoV-2 genomes and identified conserved genomics regions and landscape of mutations across thousands of virus genomes. We delineated mutation profiles spanning common genetic fingerprints (the combination of mutations in a viral assembly) and a combination of mutations that appear in only a small number of patients. We developed a targeted sequencing assay by selecting primers from the conserved viral genome regions to flank frequent mutations. Using a cohort of 100 SARS-CoV-2 clinical samples, we identified genetic fingerprints consisting of strain-specific mutations seen across populations and de novo quasispecies mutations localized to individual infections. We compared the mutation profiles of viral samples undergoing analysis with the features of the pangenome. Conclusions We conducted an analysis for viral mutation profiles that provide the basis of genetic fingerprints. Our study linked pangenome analysis with targeted deep sequenced SARS-CoV-2 clinical samples. We identified quasispecies mutations occurring within individual patients and determined their general prevalence when compared to over 70,000 other strains. Analysis of these genetic fingerprints may provide a way of conducting molecular contact tracing.
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Affiliation(s)
- Billy T Lau
- Division of Oncology, Department of Medicine, Stanford University School of Medicine, 269 Campus Drive, CCSR 1120, Stanford, CA, 94305-5151, USA.,Stanford Genome Technology Center West, Stanford University, Palo Alto, CA, 94304, USA
| | - Dmitri Pavlichin
- Division of Oncology, Department of Medicine, Stanford University School of Medicine, 269 Campus Drive, CCSR 1120, Stanford, CA, 94305-5151, USA
| | - Anna C Hooker
- Division of Oncology, Department of Medicine, Stanford University School of Medicine, 269 Campus Drive, CCSR 1120, Stanford, CA, 94305-5151, USA
| | - Alison Almeda
- Division of Oncology, Department of Medicine, Stanford University School of Medicine, 269 Campus Drive, CCSR 1120, Stanford, CA, 94305-5151, USA
| | - Giwon Shin
- Division of Oncology, Department of Medicine, Stanford University School of Medicine, 269 Campus Drive, CCSR 1120, Stanford, CA, 94305-5151, USA
| | - Jiamin Chen
- Division of Oncology, Department of Medicine, Stanford University School of Medicine, 269 Campus Drive, CCSR 1120, Stanford, CA, 94305-5151, USA
| | - Malaya K Sahoo
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Chun Hong Huang
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Benjamin A Pinsky
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, 94305, USA.,Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Ho Joon Lee
- Division of Oncology, Department of Medicine, Stanford University School of Medicine, 269 Campus Drive, CCSR 1120, Stanford, CA, 94305-5151, USA.
| | - Hanlee P Ji
- Division of Oncology, Department of Medicine, Stanford University School of Medicine, 269 Campus Drive, CCSR 1120, Stanford, CA, 94305-5151, USA. .,Stanford Genome Technology Center West, Stanford University, Palo Alto, CA, 94304, USA.
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12
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Lost in deletion: The enigmatic ORF8 protein of SARS-CoV-2. Biochem Biophys Res Commun 2021; 538:116-124. [PMID: 33685621 PMCID: PMC7577707 DOI: 10.1016/j.bbrc.2020.10.045] [Citation(s) in RCA: 85] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 10/18/2020] [Indexed: 12/15/2022]
Abstract
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genome contains nine open reading frames (ORFs) that encode for accessory proteins which, although dispensable for viral replication, are important for the modulation of the host infected cell metabolism and innate immunity evasion. Among those, the ORF8 gene encodes for the homonymous multifunctional, highly immunogenic, immunoglobulin-like protein that was recently found to inhibit presentation of viral antigens by class I major histocompatibility complex, suppress the type I interferon antiviral response and interact with host factors involved in pulmonary inflammation and fibrogenesis. Moreover, the ORF8 is a hypervariable gene rapidly evolving among SARS-related coronaviruses, with a tendency to recombine and undergo deletions that are deemed to facilitate the virus adaptation to the human host. Intriguingly, SARS-CoV-2 variants isolated in the beginning of the coronavirus disease 2019 (Covid-19) pandemic that were deleted of the ORF8 gene have been associated to milder symptoms and better disease outcome. This minireview summarizes the current knowledge on the SARS-CoV-2 ORF8 protein in perspective to its potential as antiviral target and with special emphasis on the biochemical, biophysical and structural aspects of its molecular biology.
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13
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Lau BT, Pavlichin D, Hooker AC, Almeda A, Shin G, Chen J, Sahoo MK, Huang C, Pinsky BA, Lee H, Ji HP. Profiling SARS-CoV-2 mutation fingerprints that range from the viral pangenome to individual infection quasispecies. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2020:2020.11.02.20224816. [PMID: 33173909 PMCID: PMC7654905 DOI: 10.1101/2020.11.02.20224816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Background The genome of SARS-CoV-2 is susceptible to mutations during viral replication due to the errors generated by RNA-dependent RNA polymerases. These mutations enable the SARS-CoV-2 to evolve into new strains. Viral quasispecies emerge from de novo mutations that occur in individual patients. In combination, these sets of viral mutations provide distinct genetic fingerprints that reveal the patterns of transmission and have utility in contract tracing. Methods Leveraging thousands of sequenced SARS-CoV-2 genomes, we performed a viral pangenome analysis to identify conserved genomic sequences. We used a rapid and highly efficient computational approach that relies on k-mers, short tracts of sequence, instead of conventional sequence alignment. Using this method, we annotated viral mutation signatures that were associated with specific strains. Based on these highly conserved viral sequences, we developed a rapid and highly scalable targeted sequencing assay to identify mutations, detect quasispecies and identify mutation signatures from patients. These results were compared to the pangenome genetic fingerprints. Results We built a k-mer index for thousands of SARS-CoV-2 genomes and identified conserved genomics regions and landscape of mutations across thousands of virus genomes. We delineated mutation profiles spanning common genetic fingerprints (the combination of mutations in a viral assembly) and rare ones that occur in only small fraction of patients. We developed a targeted sequencing assay by selecting primers from the conserved viral genome regions to flank frequent mutations. Using a cohort of SARS-CoV-2 clinical samples, we identified genetic fingerprints consisting of strain-specific mutations seen across populations and de novo quasispecies mutations localized to individual infections. We compared the mutation profiles of viral samples undergoing analysis with the features of the pangenome. Conclusions We conducted an analysis for viral mutation profiles that provide the basis of genetic fingerprints. Our study linked pangenome analysis with targeted deep sequenced SARS-CoV-2 clinical samples. We identified quasispecies mutations occurring within individual patients, mutations demarcating dominant species and the prevalence of mutation signatures, of which a significant number were relatively unique. Analysis of these genetic fingerprints may provide a way of conducting molecular contact tracing.
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Affiliation(s)
- Billy T. Lau
- Division of Oncology, Department of Medicine, Stanford University School of Medicine, Stanford, CA, 94305, United States
- Stanford Genome Technology Center West, Stanford University, Palo Alto, CA, 94304, United States
| | - Dmitri Pavlichin
- Division of Oncology, Department of Medicine, Stanford University School of Medicine, Stanford, CA, 94305, United States
| | - Anna C. Hooker
- Division of Oncology, Department of Medicine, Stanford University School of Medicine, Stanford, CA, 94305, United States
| | - Alison Almeda
- Division of Oncology, Department of Medicine, Stanford University School of Medicine, Stanford, CA, 94305, United States
| | - Giwon Shin
- Division of Oncology, Department of Medicine, Stanford University School of Medicine, Stanford, CA, 94305, United States
| | - Jiamin Chen
- Division of Oncology, Department of Medicine, Stanford University School of Medicine, Stanford, CA, 94305, United States
| | - Malaya K. Sahoo
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, 94305, United States
| | - ChunHong Huang
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, 94305, United States
| | - Benjamin A. Pinsky
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, 94305, United States
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, CA, 94305, United States
| | - HoJoon Lee
- Division of Oncology, Department of Medicine, Stanford University School of Medicine, Stanford, CA, 94305, United States
| | - Hanlee P. Ji
- Division of Oncology, Department of Medicine, Stanford University School of Medicine, Stanford, CA, 94305, United States
- Stanford Genome Technology Center West, Stanford University, Palo Alto, CA, 94304, United States
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14
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Mohammad S, Bouchama A, Mohammad Alharbi B, Rashid M, Saleem Khatlani T, Gaber NS, Malik SS. SARS-CoV-2 ORF8 and SARS-CoV ORF8ab: Genomic Divergence and Functional Convergence. Pathogens 2020; 9:E677. [PMID: 32825438 PMCID: PMC7558349 DOI: 10.3390/pathogens9090677] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 08/17/2020] [Accepted: 08/19/2020] [Indexed: 01/18/2023] Open
Abstract
The COVID-19 pandemic, in the first seven months, has led to more than 15 million confirmed infected cases and 600,000 deaths. SARS-CoV-2, the causative agent for COVID-19, has proved to be a great challenge for its ability to spread in asymptomatic stages and the diverse disease spectrum it has generated. This has created a challenge of unimaginable magnitude, not only affecting human health and life but also potentially generating a long-lasting socioeconomic impact. Both medical sciences and biomedical research have also been challenged, consequently leading to a large number of clinical trials and vaccine initiatives. While known proteins of pathobiological importance are targets for these therapeutic approaches, it is imperative to explore other factors of viral significance. Accessory proteins are one such trait that have diverse roles in coronavirus pathobiology. Here, we analyze certain genomic characteristics of SARS-CoV-2 accessory protein ORF8 and predict its protein features. We have further reviewed current available literature regarding its function and comparatively evaluated these and other features of ORF8 and ORF8ab, its homolog from SARS-CoV. Because coronaviruses have been infecting humans repeatedly and might continue to do so, we therefore expect this study to aid in the development of holistic understanding of these proteins. Despite low nucleotide and protein identity and differentiating genome level characteristics, there appears to be significant structural integrity and functional proximity between these proteins pointing towards their high significance. There is further need for comprehensive genomics and structural-functional studies to lead towards definitive conclusions regarding their criticality and that can eventually define their relevance to therapeutics development.
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Affiliation(s)
- Sameer Mohammad
- Experimental Medicine Department, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, MNGHA, Riyadh 11426, Saudi Arabia; (S.M.); (A.B.); (B.M.A.); (N.S.G.)
| | - Abderrezak Bouchama
- Experimental Medicine Department, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, MNGHA, Riyadh 11426, Saudi Arabia; (S.M.); (A.B.); (B.M.A.); (N.S.G.)
| | - Bothina Mohammad Alharbi
- Experimental Medicine Department, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, MNGHA, Riyadh 11426, Saudi Arabia; (S.M.); (A.B.); (B.M.A.); (N.S.G.)
| | - Mamoon Rashid
- Bioinformatics and Biostatistics Department, King Abdullah International Medical Research Center, King~Saud bin Abdulaziz University for Health Sciences, MNGHA, Riyadh 11426, Saudi Arabia;
| | - Tanveer Saleem Khatlani
- Stem Cells Unit, Department of Cellular Therapy, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, MNGHA, Riyadh 11426, Saudi Arabia;
| | - Nusaibah S. Gaber
- Experimental Medicine Department, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, MNGHA, Riyadh 11426, Saudi Arabia; (S.M.); (A.B.); (B.M.A.); (N.S.G.)
| | - Shuja Shafi Malik
- Experimental Medicine Department, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, MNGHA, Riyadh 11426, Saudi Arabia; (S.M.); (A.B.); (B.M.A.); (N.S.G.)
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15
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Yu J. From Mutation Signature to Molecular Mechanism in the RNA World: A Case of SARS-CoV-2. GENOMICS PROTEOMICS & BIOINFORMATICS 2020; 18:627-639. [PMID: 32739507 PMCID: PMC7391168 DOI: 10.1016/j.gpb.2020.07.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 07/10/2020] [Accepted: 07/23/2020] [Indexed: 02/07/2023]
Affiliation(s)
- Jun Yu
- China National Center for Bioinformation, Beijing 100101, China; CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100190, China.
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16
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Su YCF, Anderson DE, Young BE, Linster M, Zhu F, Jayakumar J, Zhuang Y, Kalimuddin S, Low JGH, Tan CW, Chia WN, Mak TM, Octavia S, Chavatte JM, Lee RTC, Pada S, Tan SY, Sun L, Yan GZ, Maurer-Stroh S, Mendenhall IH, Leo YS, Lye DC, Wang LF, Smith GJD. Discovery and Genomic Characterization of a 382-Nucleotide Deletion in ORF7b and ORF8 during the Early Evolution of SARS-CoV-2. mBio 2020; 11:e01610-20. [PMID: 32694143 PMCID: PMC7374062 DOI: 10.1128/mbio.01610-20] [Citation(s) in RCA: 196] [Impact Index Per Article: 49.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 06/23/2020] [Indexed: 12/27/2022] Open
Abstract
To date, limited genetic changes in the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genome have been described. Here, we report a 382-nucleotide (nt) deletion in SARS-CoV-2 that truncates open reading frame 7b (ORF7b) and ORF8, removing the ORF8 transcription regulatory sequence (TRS) and eliminating ORF8 transcription. The earliest 382-nt deletion variant was detected in Singapore on 29 January 2020, with the deletion viruses circulating in the country and accounting for 23.6% (45/191) of SARS-CoV-2 samples screened in this study. SARS-CoV-2 with the same deletion has since been detected in Taiwan, and other ORF7b/8 deletions of various lengths, ranging from 62 nt to 345 nt, have been observed in other geographic locations, including Australia, Bangladesh, and Spain. Mutations or deletions in ORF8 of SARS-CoV have been associated with reduced replicative fitness and virus attenuation. In contrast, the SARS-CoV-2 382-nt deletion viruses showed significantly higher replicative fitness in vitro than the wild type, while no difference was observed in patient viral load, indicating that the deletion variant viruses retained their replicative fitness. A robust antibody response to ORF8 has been observed in SARS-CoV-2 infection, suggesting that the emergence of ORF8 deletions may be due to immune-driven selection and that further deletion variants may emerge during the sustained transmission of SARS-CoV-2 in humans.IMPORTANCE During the SARS epidemic in 2003/2004, a number of deletions were observed in ORF8 of SARS-CoV, and eventually deletion variants became predominant, leading to the hypothesis that ORF8 was an evolutionary hot spot for adaptation of SARS-CoV to humans. However, due to the successful control of the SARS epidemic, the importance of these deletions for the epidemiological fitness of SARS-CoV in humans could not be established. The emergence of multiple SARS-CoV-2 strains with ORF8 deletions, combined with evidence of a robust immune response to ORF8, suggests that the lack of ORF8 may assist with host immune evasion. In addition to providing a key insight into the evolutionary behavior of SARS-CoV-2 as the virus adapts to its new human hosts, the emergence of ORF8 deletion variants may also impact vaccination strategies.
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Affiliation(s)
- Yvonne C F Su
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
| | - Danielle E Anderson
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
| | - Barnaby E Young
- National Centre for Infectious Diseases, Singapore
- Tan Tock Seng Hospital, Singapore
- Lee Kong Chian School of Medicine, Singapore
| | - Martin Linster
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
| | - Feng Zhu
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
| | - Jayanthi Jayakumar
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
| | - Yan Zhuang
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
| | - Shirin Kalimuddin
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
- Singapore General Hospital, Singapore
| | - Jenny G H Low
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
- Singapore General Hospital, Singapore
| | - Chee Wah Tan
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
| | - Wan Ni Chia
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
| | - Tze Minn Mak
- National Centre for Infectious Diseases, Singapore
| | | | | | - Raphael T C Lee
- Bioinformatics Institute, Agency for Science, Technology and Research (A*STAR), Singapore
| | | | | | | | | | - Sebastian Maurer-Stroh
- Bioinformatics Institute, Agency for Science, Technology and Research (A*STAR), Singapore
- Department of Biological Sciences, National University of Singapore, Singapore
| | - Ian H Mendenhall
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
- SingHealth Duke-NUS Global Health Institute, Singapore
| | - Yee-Sin Leo
- National Centre for Infectious Diseases, Singapore
- Tan Tock Seng Hospital, Singapore
- Lee Kong Chian School of Medicine, Singapore
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - David Chien Lye
- National Centre for Infectious Diseases, Singapore
- Tan Tock Seng Hospital, Singapore
- Lee Kong Chian School of Medicine, Singapore
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Lin-Fa Wang
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
- SingHealth Duke-NUS Global Health Institute, Singapore
- Duke Global Health Institute, Duke University, North Carolina, USA
| | - Gavin J D Smith
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
- SingHealth Duke-NUS Global Health Institute, Singapore
- Duke Global Health Institute, Duke University, North Carolina, USA
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17
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Su YCF, Anderson DE, Young BE, Linster M, Zhu F, Jayakumar J, Zhuang Y, Kalimuddin S, Low JGH, Tan CW, Chia WN, Mak TM, Octavia S, Chavatte JM, Lee RTC, Pada S, Tan SY, Sun L, Yan GZ, Maurer-Stroh S, Mendenhall IH, Leo YS, Lye DC, Wang LF, Smith GJD. Discovery and Genomic Characterization of a 382-Nucleotide Deletion in ORF7b and ORF8 during the Early Evolution of SARS-CoV-2. mBio 2020; 11:mBio.01610-20. [PMID: 32694143 DOI: 10.1101/2020.03.11.987222] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2023] Open
Abstract
To date, limited genetic changes in the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genome have been described. Here, we report a 382-nucleotide (nt) deletion in SARS-CoV-2 that truncates open reading frame 7b (ORF7b) and ORF8, removing the ORF8 transcription regulatory sequence (TRS) and eliminating ORF8 transcription. The earliest 382-nt deletion variant was detected in Singapore on 29 January 2020, with the deletion viruses circulating in the country and accounting for 23.6% (45/191) of SARS-CoV-2 samples screened in this study. SARS-CoV-2 with the same deletion has since been detected in Taiwan, and other ORF7b/8 deletions of various lengths, ranging from 62 nt to 345 nt, have been observed in other geographic locations, including Australia, Bangladesh, and Spain. Mutations or deletions in ORF8 of SARS-CoV have been associated with reduced replicative fitness and virus attenuation. In contrast, the SARS-CoV-2 382-nt deletion viruses showed significantly higher replicative fitness in vitro than the wild type, while no difference was observed in patient viral load, indicating that the deletion variant viruses retained their replicative fitness. A robust antibody response to ORF8 has been observed in SARS-CoV-2 infection, suggesting that the emergence of ORF8 deletions may be due to immune-driven selection and that further deletion variants may emerge during the sustained transmission of SARS-CoV-2 in humans.IMPORTANCE During the SARS epidemic in 2003/2004, a number of deletions were observed in ORF8 of SARS-CoV, and eventually deletion variants became predominant, leading to the hypothesis that ORF8 was an evolutionary hot spot for adaptation of SARS-CoV to humans. However, due to the successful control of the SARS epidemic, the importance of these deletions for the epidemiological fitness of SARS-CoV in humans could not be established. The emergence of multiple SARS-CoV-2 strains with ORF8 deletions, combined with evidence of a robust immune response to ORF8, suggests that the lack of ORF8 may assist with host immune evasion. In addition to providing a key insight into the evolutionary behavior of SARS-CoV-2 as the virus adapts to its new human hosts, the emergence of ORF8 deletion variants may also impact vaccination strategies.
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Affiliation(s)
- Yvonne C F Su
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
| | - Danielle E Anderson
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
| | - Barnaby E Young
- National Centre for Infectious Diseases, Singapore
- Tan Tock Seng Hospital, Singapore
- Lee Kong Chian School of Medicine, Singapore
| | - Martin Linster
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
| | - Feng Zhu
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
| | - Jayanthi Jayakumar
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
| | - Yan Zhuang
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
| | - Shirin Kalimuddin
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
- Singapore General Hospital, Singapore
| | - Jenny G H Low
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
- Singapore General Hospital, Singapore
| | - Chee Wah Tan
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
| | - Wan Ni Chia
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
| | - Tze Minn Mak
- National Centre for Infectious Diseases, Singapore
| | | | | | - Raphael T C Lee
- Bioinformatics Institute, Agency for Science, Technology and Research (A*STAR), Singapore
| | | | | | | | | | - Sebastian Maurer-Stroh
- Bioinformatics Institute, Agency for Science, Technology and Research (A*STAR), Singapore
- Department of Biological Sciences, National University of Singapore, Singapore
| | - Ian H Mendenhall
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
- SingHealth Duke-NUS Global Health Institute, Singapore
| | - Yee-Sin Leo
- National Centre for Infectious Diseases, Singapore
- Tan Tock Seng Hospital, Singapore
- Lee Kong Chian School of Medicine, Singapore
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - David Chien Lye
- National Centre for Infectious Diseases, Singapore
- Tan Tock Seng Hospital, Singapore
- Lee Kong Chian School of Medicine, Singapore
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Lin-Fa Wang
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
- SingHealth Duke-NUS Global Health Institute, Singapore
- Duke Global Health Institute, Duke University, North Carolina, USA
| | - Gavin J D Smith
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
- SingHealth Duke-NUS Global Health Institute, Singapore
- Duke Global Health Institute, Duke University, North Carolina, USA
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18
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Kaushal N, Gupta Y, Goyal M, Khaiboullina SF, Baranwal M, Verma SC. Mutational Frequencies of SARS-CoV-2 Genome during the Beginning Months of the Outbreak in USA. Pathogens 2020; 9:E565. [PMID: 32668692 PMCID: PMC7400123 DOI: 10.3390/pathogens9070565] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 07/07/2020] [Accepted: 07/11/2020] [Indexed: 11/29/2022] Open
Abstract
SARS-CoV-2 has spread very quickly from its first reported case on 19 January 2020 in the United Stated of America, leading WHO to declare pandemic by 11 March 2020. RNA viruses accumulate mutations following replication and passage in human population, which prompted us to determine the rate and the regions (hotspots) of the viral genome with high rates of mutation. We analyzed the rate of mutation accumulation over a period of 11 weeks (submitted between 19th January to 15 April 2020) in USA SARS-CoV-2 genome. Our analysis identified that majority of the viral genes accumulated mutations, although with varying rates and these included NSP2, NSP3, RdRp, helicase, Spike, ORF3a, ORF8, and Nucleocapsid protein. Sixteen mutations accumulated in Spike protein in which four mutations are located in the receptor binding domain. Intriguingly, we identified a fair number of viral proteins (NSP7, NSP9, NSP10, NSP11, Envelop, ORF6, and ORF7b proteins), which did not accumulate any mutation. Limited changes in these proteins may suggest that they have conserved functions, which are essential for virus propagation. This provides a basis for a better understanding of the genetic variation in SARS-CoV-2 circulating in the US, which could help in identifying potential therapeutic targets for controlling COVID-19.
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Affiliation(s)
- Neha Kaushal
- Department of Biotechnology, Thapar Institute of Engineering and Technology, Patiala 147004, India; (N.K.); (Y.G.); (M.G.)
| | - Yogita Gupta
- Department of Biotechnology, Thapar Institute of Engineering and Technology, Patiala 147004, India; (N.K.); (Y.G.); (M.G.)
| | - Mehendi Goyal
- Department of Biotechnology, Thapar Institute of Engineering and Technology, Patiala 147004, India; (N.K.); (Y.G.); (M.G.)
- Talwar and Talwar Consultants, Mohali 160055, India
| | - Svetlana F. Khaiboullina
- Department of Microbiology and Immunology, University of Nevada, Reno, NV 89557, USA;
- Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, 420008 Tatarstan, Russia
| | - Manoj Baranwal
- Department of Biotechnology, Thapar Institute of Engineering and Technology, Patiala 147004, India; (N.K.); (Y.G.); (M.G.)
| | - Subhash C. Verma
- Department of Microbiology and Immunology, University of Nevada, Reno, NV 89557, USA;
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19
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Muth D, Corman VM, Roth H, Binger T, Dijkman R, Gottula LT, Gloza-Rausch F, Balboni A, Battilani M, Rihtarič D, Toplak I, Ameneiros RS, Pfeifer A, Thiel V, Drexler JF, Müller MA, Drosten C. Attenuation of replication by a 29 nucleotide deletion in SARS-coronavirus acquired during the early stages of human-to-human transmission. Sci Rep 2018; 8:15177. [PMID: 30310104 PMCID: PMC6181990 DOI: 10.1038/s41598-018-33487-8] [Citation(s) in RCA: 145] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 09/27/2018] [Indexed: 12/03/2022] Open
Abstract
A 29 nucleotide deletion in open reading frame 8 (ORF8) is the most obvious genetic change in severe acute respiratory syndrome coronavirus (SARS-CoV) during its emergence in humans. In spite of intense study, it remains unclear whether the deletion actually reflects adaptation to humans. Here we engineered full, partially deleted (-29 nt), and fully deleted ORF8 into a SARS-CoV infectious cDNA clone, strain Frankfurt-1. Replication of the resulting viruses was compared in primate cell cultures as well as Rhinolophus bat cells made permissive for SARS-CoV replication by lentiviral transduction of the human angiotensin-converting enzyme 2 receptor. Cells from cotton rat, goat, and sheep provided control scenarios that represent host systems in which SARS-CoV is neither endemic nor epidemic. Independent of the cell system, the truncation of ORF8 (29 nt deletion) decreased replication up to 23-fold. The effect was independent of the type I interferon response. The 29 nt deletion in SARS-CoV is a deleterious mutation acquired along the initial human-to-human transmission chain. The resulting loss of fitness may be due to a founder effect, which has rarely been documented in processes of viral emergence. These results have important implications for the retrospective assessment of the threat posed by SARS.
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Affiliation(s)
- Doreen Muth
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Virology, Charitéplatz 1, 10117, Berlin, Germany
- German Center for Infection Research (DZIF), Berlin, Germany
- Institute of Virology, University of Bonn Medical Centre, Sigmund-Freud-Str. 25, 53127, Bonn, Germany
| | - Victor Max Corman
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Virology, Charitéplatz 1, 10117, Berlin, Germany
- German Center for Infection Research (DZIF), Berlin, Germany
- Institute of Virology, University of Bonn Medical Centre, Sigmund-Freud-Str. 25, 53127, Bonn, Germany
| | - Hanna Roth
- Institute of Virology, University of Bonn Medical Centre, Sigmund-Freud-Str. 25, 53127, Bonn, Germany
| | - Tabea Binger
- Institute of Virology, University of Bonn Medical Centre, Sigmund-Freud-Str. 25, 53127, Bonn, Germany
| | - Ronald Dijkman
- Federal Department of Home Affairs, Institute of Virology and Immunology IVI, Bern and Mittelhäusern, Sensemattstrasse 293, 3147, Mittelhäusern, Switzerland
- Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Länggassstrasse 122, 3012, Bern, Switzerland
| | - Lina Theresa Gottula
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Virology, Charitéplatz 1, 10117, Berlin, Germany
- German Center for Infection Research (DZIF), Berlin, Germany
- Institute of Virology, University of Bonn Medical Centre, Sigmund-Freud-Str. 25, 53127, Bonn, Germany
| | - Florian Gloza-Rausch
- Noctalis, Centre for Bat Protection and Information, Oberbergstraße 27, 23795, Bad Segeberg, Germany
| | - Andrea Balboni
- Dipartimento di Scienze Mediche Veterinarie, Facoltà di Medicina Veterinaria, Alma Mater Studiorum-Università di Bologna, Via Tolara di Sopra 50, 40064, Ozzano Emilia, (BO), Italy
| | - Mara Battilani
- Dipartimento di Scienze Mediche Veterinarie, Facoltà di Medicina Veterinaria, Alma Mater Studiorum-Università di Bologna, Via Tolara di Sopra 50, 40064, Ozzano Emilia, (BO), Italy
| | - Danijela Rihtarič
- Virology Unit, Institute of Microbiology and Parasitology, Veterinary Faculty, University of Ljubljana, Gerbičeva 60, 1000, Ljubljana, Slovenia
| | - Ivan Toplak
- Virology Unit, Institute of Microbiology and Parasitology, Veterinary Faculty, University of Ljubljana, Gerbičeva 60, 1000, Ljubljana, Slovenia
| | - Ramón Seage Ameneiros
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Albert-Einstein Allee 11, 89069, Ulm, Germany
- Group Morcegos de Galicia, Drosera Society, Pdo. Magdalena, G-2, 2° esq, 15320, As Pontes, Spain
| | - Alexander Pfeifer
- Institute for Pharmacology and Toxicology, University of Bonn, Sigmund-Freud-Str. 25, 53127, Bonn, Germany
| | - Volker Thiel
- Federal Department of Home Affairs, Institute of Virology and Immunology IVI, Bern and Mittelhäusern, Sensemattstrasse 293, 3147, Mittelhäusern, Switzerland
- Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Länggassstrasse 122, 3012, Bern, Switzerland
| | - Jan Felix Drexler
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Virology, Charitéplatz 1, 10117, Berlin, Germany
- German Center for Infection Research (DZIF), Berlin, Germany
- Institute of Virology, University of Bonn Medical Centre, Sigmund-Freud-Str. 25, 53127, Bonn, Germany
| | - Marcel Alexander Müller
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Virology, Charitéplatz 1, 10117, Berlin, Germany
- German Center for Infection Research (DZIF), Berlin, Germany
- Institute of Virology, University of Bonn Medical Centre, Sigmund-Freud-Str. 25, 53127, Bonn, Germany
| | - Christian Drosten
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Virology, Charitéplatz 1, 10117, Berlin, Germany.
- German Center for Infection Research (DZIF), Berlin, Germany.
- Institute of Virology, University of Bonn Medical Centre, Sigmund-Freud-Str. 25, 53127, Bonn, Germany.
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Role of Severe Acute Respiratory Syndrome Coronavirus Viroporins E, 3a, and 8a in Replication and Pathogenesis. mBio 2018; 9:mBio.02325-17. [PMID: 29789363 PMCID: PMC5964350 DOI: 10.1128/mbio.02325-17] [Citation(s) in RCA: 209] [Impact Index Per Article: 34.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Viroporins are viral proteins with ion channel (IC) activity that play an important role in several processes, including virus replication and pathogenesis. While many coronaviruses (CoVs) encode two viroporins, severe acute respiratory syndrome CoV (SARS-CoV) encodes three: proteins 3a, E, and 8a. Additionally, proteins 3a and E have a PDZ-binding motif (PBM), which can potentially bind over 400 cellular proteins which contain a PDZ domain, making them potentially important for the control of cell function. In the present work, a comparative study of the functional motifs included within the SARS-CoV viroporins was performed, mostly focusing on the roles of the IC and PBM of E and 3a proteins. Our results showed that the full-length E and 3a proteins were required for maximal SARS-CoV replication and virulence, whereas viroporin 8a had only a minor impact on these activities. A virus missing both the E and 3a proteins was not viable, whereas the presence of either protein with a functional PBM restored virus viability. E protein IC activity and the presence of its PBM were necessary for virulence in mice. In contrast, the presence or absence of the homologous motifs in protein 3a did not influence virus pathogenicity. Therefore, dominance of the IC and PBM of protein E over those of protein 3a was demonstrated in the induction of pathogenesis in mice.IMPORTANCE Collectively, these results demonstrate key roles for the ion channel and PBM domains in optimal virus replication and pathogenesis and suggest that the viral viroporins and PBMs are suitable targets for antiviral therapy and for mutation in attenuated SARS-CoV vaccines.
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21
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Lu X, Rowe LA, Frace M, Stevens J, Abedi GR, Elnile O, Banassir T, Al-Masri M, Watson JT, Assiri A, Erdman DD. Spike gene deletion quasispecies in serum of patient with acute MERS-CoV infection. J Med Virol 2016; 89:542-545. [PMID: 27486688 PMCID: PMC7166981 DOI: 10.1002/jmv.24652] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/10/2016] [Indexed: 01/01/2023]
Abstract
The spike glycoprotein of the Middle East respiratory coronavirus (MERS-CoV) facilitates receptor binding and cell entry. During investigation of a multi-facility outbreak of MERS-CoV in Taif, Saudi Arabia, we identified a mixed population of wild-type and variant sequences with a large 530 nucleotide deletion in the spike gene from the serum of one patient. The out of frame deletion predicted loss of most of the S2 subunit of the spike protein leaving the S1 subunit with an intact receptor binding domain. This finding documents human infection with a novel genetic variant of MERS-CoV present as a quasispecies. J. Med. Virol. 89:542-545, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Xiaoyan Lu
- Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Lori A Rowe
- Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Michael Frace
- Centers for Disease Control and Prevention, Atlanta, Georgia
| | - James Stevens
- Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Glen R Abedi
- Centers for Disease Control and Prevention, Atlanta, Georgia
| | | | | | | | - John T Watson
- Centers for Disease Control and Prevention, Atlanta, Georgia
| | | | - Dean D Erdman
- Centers for Disease Control and Prevention, Atlanta, Georgia
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22
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Jimenez-Guardeño JM, Regla-Nava JA, Nieto-Torres JL, DeDiego ML, Castaño-Rodriguez C, Fernandez-Delgado R, Perlman S, Enjuanes L. Identification of the Mechanisms Causing Reversion to Virulence in an Attenuated SARS-CoV for the Design of a Genetically Stable Vaccine. PLoS Pathog 2015; 11:e1005215. [PMID: 26513244 PMCID: PMC4626112 DOI: 10.1371/journal.ppat.1005215] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 09/18/2015] [Indexed: 12/15/2022] Open
Abstract
A SARS-CoV lacking the full-length E gene (SARS-CoV-∆E) was attenuated and an effective vaccine. Here, we show that this mutant virus regained fitness after serial passages in cell culture or in vivo, resulting in the partial duplication of the membrane gene or in the insertion of a new sequence in gene 8a, respectively. The chimeric proteins generated in cell culture increased virus fitness in vitro but remained attenuated in mice. In contrast, during SARS-CoV-∆E passage in mice, the virus incorporated a mutated variant of 8a protein, resulting in reversion to a virulent phenotype. When the full-length E protein was deleted or its PDZ-binding motif (PBM) was mutated, the revertant viruses either incorporated a novel chimeric protein with a PBM or restored the sequence of the PBM on the E protein, respectively. Similarly, after passage in mice, SARS-CoV-∆E protein 8a mutated, to now encode a PBM, and also regained virulence. These data indicated that the virus requires a PBM on a transmembrane protein to compensate for removal of this motif from the E protein. To increase the genetic stability of the vaccine candidate, we introduced small attenuating deletions in E gene that did not affect the endogenous PBM, preventing the incorporation of novel chimeric proteins in the virus genome. In addition, to increase vaccine biosafety, we introduced additional attenuating mutations into the nsp1 protein. Deletions in the carboxy-terminal region of nsp1 protein led to higher host interferon responses and virus attenuation. Recombinant viruses including attenuating mutations in E and nsp1 genes maintained their attenuation after passage in vitro and in vivo. Further, these viruses fully protected mice against challenge with the lethal parental virus, and are therefore safe and stable vaccine candidates for protection against SARS-CoV. Zoonotic coronaviruses, including SARS-CoV, Middle East respiratory syndrome (MERS-CoV), porcine epidemic diarrhea virus (PEDV) and swine delta coronavirus (SDCoV) have recently emerged causing high morbidity and mortality in human or piglets. No fully protective therapy is still available for these CoVs. Therefore, the development of efficient vaccines is a high priority. Live attenuated vaccines are considered most effective compared to other types of vaccines, as they induce a long-lived, balanced immune response. However, safety is the main concern of this type of vaccines because attenuated viruses can eventually revert to a virulent phenotype. Therefore, an essential feature of any live attenuated vaccine candidate is its stability. In addition, introduction of several safety guards is advisable to increase vaccine safety. In this manuscript, we analyzed the mechanisms by which an attenuated SARS-CoV reverted to a virulent phenotype and describe the introduction of attenuating deletions that maintained virus stability. The virus, engineered with two safety guards, provided full protection against challenge with a lethal SARS-CoV. Understanding the molecular mechanisms leading to pathogenicity and the in vivo evaluation of vaccine genetic stability contributed to a rational design of a promising SARS-CoV vaccine.
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Affiliation(s)
- Jose M. Jimenez-Guardeño
- Department of Molecular and Cell Biology, Centro Nacional de Biotecnología (CNB-CSIC), Campus Universidad Autónoma de Madrid, Madrid, Spain
| | - Jose A. Regla-Nava
- Department of Molecular and Cell Biology, Centro Nacional de Biotecnología (CNB-CSIC), Campus Universidad Autónoma de Madrid, Madrid, Spain
| | - Jose L. Nieto-Torres
- Department of Molecular and Cell Biology, Centro Nacional de Biotecnología (CNB-CSIC), Campus Universidad Autónoma de Madrid, Madrid, Spain
| | - Marta L. DeDiego
- Department of Molecular and Cell Biology, Centro Nacional de Biotecnología (CNB-CSIC), Campus Universidad Autónoma de Madrid, Madrid, Spain
| | - Carlos Castaño-Rodriguez
- Department of Molecular and Cell Biology, Centro Nacional de Biotecnología (CNB-CSIC), Campus Universidad Autónoma de Madrid, Madrid, Spain
| | - Raul Fernandez-Delgado
- Department of Molecular and Cell Biology, Centro Nacional de Biotecnología (CNB-CSIC), Campus Universidad Autónoma de Madrid, Madrid, Spain
| | - Stanley Perlman
- Department of Microbiology, University of Iowa, Iowa City, Iowa, United States of America
| | - Luis Enjuanes
- Department of Molecular and Cell Biology, Centro Nacional de Biotecnología (CNB-CSIC), Campus Universidad Autónoma de Madrid, Madrid, Spain
- * E-mail:
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23
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DeDiego ML, Nieto-Torres JL, Jimenez-Guardeño JM, Regla-Nava JA, Castaño-Rodriguez C, Fernandez-Delgado R, Usera F, Enjuanes L. Coronavirus virulence genes with main focus on SARS-CoV envelope gene. Virus Res 2014; 194:124-37. [PMID: 25093995 PMCID: PMC4261026 DOI: 10.1016/j.virusres.2014.07.024] [Citation(s) in RCA: 119] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Revised: 07/21/2014] [Accepted: 07/24/2014] [Indexed: 12/20/2022]
Abstract
Coronavirus (CoV) infection is usually detected by cellular sensors, which trigger the activation of the innate immune system. Nevertheless, CoVs have evolved viral proteins that target different signaling pathways to counteract innate immune responses. Some CoV proteins act as antagonists of interferon (IFN) by inhibiting IFN production or signaling, aspects that are briefly addressed in this review. After CoV infection, potent cytokines relevant in controlling virus infections and priming adaptive immune responses are also generated. However, an uncontrolled induction of these proinflammatory cytokines can lead to pathogenesis and disease severity as described for SARS-CoV and MERS-CoV. The cellular pathways mediated by interferon regulatory factor (IRF)-3 and -7, activating transcription factor (ATF)-2/jun, activator protein (AP)-1, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and nuclear factor of activated T cells (NF-AT), are the main drivers of the inflammatory response triggered after viral infections, with NF-κB pathway the most frequently activated. Key CoV proteins involved in the regulation of these pathways and the proinflammatory immune response are revisited in this manuscript. It has been shown that the envelope (E) protein plays a variable role in CoV morphogenesis, depending on the CoV genus, being absolutely essential in some cases (genus α CoVs such as TGEV, and genus β CoVs such as MERS-CoV), but not in others (genus β CoVs such as MHV or SARS-CoV). A comprehensive accumulation of data has shown that the relatively small E protein elicits a strong influence on the interaction of SARS-CoV with the host. In fact, after infection with viruses in which this protein has been deleted, increased cellular stress and unfolded protein responses, apoptosis, and augmented host immune responses were observed. In contrast, the presence of E protein activated a pathogenic inflammatory response that may cause death in animal models and in humans. The modification or deletion of different motifs within E protein, including the transmembrane domain that harbors an ion channel activity, small sequences within the middle region of the carboxy-terminus of E protein, and its most carboxy-terminal end, which contains a PDZ domain-binding motif (PBM), is sufficient to attenuate the virus. Interestingly, a comprehensive collection of SARS-CoVs in which these motifs have been modified elicited full and long-term protection even in old mice, making those deletion mutants promising vaccine candidates. These data indicate that despite its small size, E protein drastically influences the replication of CoVs and their pathogenicity. Although E protein is not essential for CoV genome replication or subgenomic mRNA synthesis, it affects virus morphogenesis, budding, assembly, intracellular trafficking, and virulence. In fact, E protein is responsible in a significant proportion of the inflammasome activation and the associated inflammation elicited by SARS-CoV in the lung parenchyma. This exacerbated inflammation causes edema accumulation leading to acute respiratory distress syndrome (ARDS) and, frequently, to the death of infected animal models or human patients.
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Affiliation(s)
- Marta L DeDiego
- Department of Molecular and Cell Biology, National Center of Biotechnology (CNB-CSIC), Campus Universidad Autonoma de Madrid, Madrid, Spain
| | - Jose L Nieto-Torres
- Department of Molecular and Cell Biology, National Center of Biotechnology (CNB-CSIC), Campus Universidad Autonoma de Madrid, Madrid, Spain
| | - Jose M Jimenez-Guardeño
- Department of Molecular and Cell Biology, National Center of Biotechnology (CNB-CSIC), Campus Universidad Autonoma de Madrid, Madrid, Spain
| | - Jose A Regla-Nava
- Department of Molecular and Cell Biology, National Center of Biotechnology (CNB-CSIC), Campus Universidad Autonoma de Madrid, Madrid, Spain
| | - Carlos Castaño-Rodriguez
- Department of Molecular and Cell Biology, National Center of Biotechnology (CNB-CSIC), Campus Universidad Autonoma de Madrid, Madrid, Spain
| | - Raul Fernandez-Delgado
- Department of Molecular and Cell Biology, National Center of Biotechnology (CNB-CSIC), Campus Universidad Autonoma de Madrid, Madrid, Spain
| | - Fernando Usera
- Department of Biosafety, National Center of Biotechnology (CNB-CSIC), Campus Universidad Autonoma de Madrid, Madrid, Spain
| | - Luis Enjuanes
- Department of Molecular and Cell Biology, National Center of Biotechnology (CNB-CSIC), Campus Universidad Autonoma de Madrid, Madrid, Spain.
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24
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Liu DX, Fung TS, Chong KKL, Shukla A, Hilgenfeld R. Accessory proteins of SARS-CoV and other coronaviruses. Antiviral Res 2014; 109:97-109. [PMID: 24995382 PMCID: PMC7113789 DOI: 10.1016/j.antiviral.2014.06.013] [Citation(s) in RCA: 292] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 06/17/2014] [Accepted: 06/23/2014] [Indexed: 01/21/2023]
Abstract
The huge RNA genome of SARS coronavirus comprises a number of open reading frames that code for a total of eight accessory proteins. Although none of these are essential for virus replication, some appear to have a role in virus pathogenesis. Notably, some SARS-CoV accessory proteins have been shown to modulate the interferon signaling pathways and the production of pro-inflammatory cytokines. The structural information on these proteins is also limited, with only two (p7a and p9b) having their structures determined by X-ray crystallography. This review makes an attempt to summarize the published knowledge on SARS-CoV accessory proteins, with an emphasis on their involvement in virus-host interaction. The accessory proteins of other coronaviruses are also briefly discussed. This paper forms part of a series of invited articles in Antiviral Research on "From SARS to MERS: 10 years of research on highly pathogenic human coronaviruses" (see Introduction by Hilgenfeld and Peiris (2013)).
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Affiliation(s)
- Ding Xiang Liu
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore.
| | - To Sing Fung
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Kelvin Kian-Long Chong
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Aditi Shukla
- Institute of Biochemistry, Center for Structural and Cell Biology in Medicine, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany; German Center for Infection Research (DZIF), University of Lübeck, Germany
| | - Rolf Hilgenfeld
- Institute of Biochemistry, Center for Structural and Cell Biology in Medicine, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany; German Center for Infection Research (DZIF), University of Lübeck, Germany
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25
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McBride R, Fielding BC. The role of severe acute respiratory syndrome (SARS)-coronavirus accessory proteins in virus pathogenesis. Viruses 2012. [PMID: 23202509 PMCID: PMC3509677 DOI: 10.3390/v4112902] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
A respiratory disease caused by a novel coronavirus, termed the severe acute respiratory syndrome coronavirus (SARS-CoV), was first reported in China in late 2002. The subsequent efficient human-to-human transmission of this virus eventually affected more than 30 countries worldwide, resulting in a mortality rate of ~10% of infected individuals. The spread of the virus was ultimately controlled by isolation of infected individuals and there has been no infections reported since April 2004. However, the natural reservoir of the virus was never identified and it is not known if this virus will re-emerge and, therefore, research on this virus continues. The SARS-CoV genome is about 30 kb in length and is predicted to contain 14 functional open reading frames (ORFs). The genome encodes for proteins that are homologous to known coronavirus proteins, such as the replicase proteins (ORFs 1a and 1b) and the four major structural proteins: nucleocapsid (N), spike (S), membrane (M) and envelope (E). SARS-CoV also encodes for eight unique proteins, called accessory proteins, with no known homologues. This review will summarize the current knowledge on SARS-CoV accessory proteins and will include: (i) expression and processing; (ii) the effects on cellular processes; and (iii) functional studies.
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Affiliation(s)
- Ruth McBride
- Anatomy Cluster, Department of Medical Biosciences, Faculty of Natural Sciences, University of the Western Cape, Private Bag X17, Modderdam Road, Bellville, Western Cape, 7535, South Africa;
| | - Burtram C. Fielding
- Molecular Biology and Virology Laboratory, Department of Medical Biosciences, Faculty of Natural Sciences, University of the Western Cape, Private Bag X17, Modderdam Road, Bellville, Western Cape, 7535, South Africa
- Author to whom correspondence should be addressed; ; Tel.: +27-21-959-3620; Fax: +27-21-959-3125
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26
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Molecular and Biochemical Characterization of the SARS-CoV Accessory Proteins ORF8a, ORF8b and ORF8ab. MOLECULAR BIOLOGY OF THE SARS-CORONAVIRUS 2010. [PMCID: PMC7176222 DOI: 10.1007/978-3-642-03683-5_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
A novel coronavirus was identified as the aetiological agent for the global outbreak of severe acute respiratory syndrome (SARS) at the beginning of the twenty-first century. The SARS coronavirus genome encodes for proteins that are common to all members of the coronavirus, i.e. replicase polyproteins (pp1a and pp1b) and structural proteins (spike, membrane, nucleocapsid and envelope), as well as eight accessory proteins. The accessory proteins have been designated as open reading frames (ORF) 3a, 3b, 6, 7a, 7b, 8a, 8b and 9b, and they do not show significant homology to viral proteins of other known coronaviruses. Epidemiological studies have revealed that the part of the viral genome that encodes for ORF8a and ORF8b showed major variations and the animal isolates contain an additional 29-nucleotide sequence which is absent in most of the human isolates. As a result, ORF8a and ORF8b in the human isolates become one ORF, termed ORF8ab. In this chapter, we will discuss the genetic variation in the ORF8 region, expression of ORF8a, ORF8b and ORF8ab during infection, cellular localization and posttranslational modification of ORF8a, ORF8b and ORF8ab, participation of ORF8a, ORF8b and ORF8ab in viral–viral interactions, their effects on other viral proteins and impact on viral replication and/or pathogenesis.
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27
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Pfefferle S, Krähling V, Ditt V, Grywna K, Mühlberger E, Drosten C. Reverse genetic characterization of the natural genomic deletion in SARS-Coronavirus strain Frankfurt-1 open reading frame 7b reveals an attenuating function of the 7b protein in-vitro and in-vivo. Virol J 2009; 6:131. [PMID: 19698190 PMCID: PMC2739521 DOI: 10.1186/1743-422x-6-131] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2009] [Accepted: 08/24/2009] [Indexed: 12/15/2022] Open
Abstract
During the outbreak of SARS in 2002/3, a prototype virus was isolated from a patient in Frankfurt/Germany (strain Frankfurt-1). As opposed to all other SARS-Coronavirus strains, Frankfurt-1 has a 45-nucleotide deletion in the transmembrane domain of its ORF 7b protein. When over-expressed in HEK 293 cells, the full-length protein but not the variant with the deletion caused interferon beta induction and cleavage of procaspase 3. To study the role of ORF 7b in the context of virus replication, we cloned a full genome cDNA copy of Frankfurt-1 in a bacterial artificial chromosome downstream of a T7 RNA polymerase promoter. Transfection of capped RNA transcribed from this construct yielded infectious virus that was indistinguishable from the original virus isolate. The presumed Frankfurt-1 ancestor with an intact ORF 7b was reconstructed. In CaCo-2 and HUH7 cells, but not in Vero cells, the variant carrying the ORF 7b deletion had a replicative advantage against the parental virus (4- and 6-fold increase of virus RNA in supernatant, respectively). This effect was neither associated with changes in the induction or secretion of type I interferon, nor with altered induction of apoptosis in cell culture. However, pretreatment of cells with interferon beta caused the deleted virus to replicate to higher titers than the parental strain (3.4-fold in Vero cells, 7.9-fold in CaCo-2 cells). In Syrian Golden Hamsters inoculated intranasally with 10e4 plaque forming units of either virus, mean titers of infectious virus and viral RNA in the lungs after 24 h were increased 23- and 94.8-fold, respectively, with the deleted virus. This difference could explain earlier observations of enhanced virulence of Frankfurt-1 in Hamsters as compared to other SARS-Coronavirus reference strains and identifies the SARS-CoV 7b protein as an attenuating factor with the SARS-Coronavirus genome. Because attenuation was focused on the early phase of infection in-vivo, ORF 7b might have contributed to the delayed accumulation of virus in patients that was suggested to have limited the spread of the SARS epidemic.
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Affiliation(s)
- Susanne Pfefferle
- Clinical Virology Group, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.
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The 29-nucleotide deletion present in human but not in animal severe acute respiratory syndrome coronaviruses disrupts the functional expression of open reading frame 8. J Virol 2007; 81:13876-88. [PMID: 17928347 DOI: 10.1128/jvi.01631-07] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
One of the most striking and dramatic genomic changes observed in the severe acute respiratory syndrome coronavirus (SARS-CoV) isolated from humans soon after its zoonotic transmission from palm civets was the acquisition of a characteristic 29-nucleotide deletion. This occurred in open reading frame 8 (ORF8), one of the accessory genes unique to the SARS-CoV. The function of ORF8 and the significance of the deletion are unknown. The intact ORF8 present in animal and some early human isolates encodes a 122-amino-acid polypeptide (8ab(+)), which we expressed in cells using the vaccinia virus T7 expression system. It was found to contain a cleavable signal sequence, which directs the precursor to the endoplasmic reticulum (ER) and mediates its translocation into the lumen. The cleaved protein became N-glycosylated, assembled into disulfide-linked homomultimeric complexes, and remained stably in the ER. The 29-nucleotide deletion splits ORF8 into two ORFs, 8a and 8b, encoding 39- and 84-residue polypeptides. The 8a polypeptide is likely to remain in the cytoplasm, as it is too small for its signal sequence to function and will therefore be directly released from the ribosome. However, we could not confirm this experimentally due to the lack of proper antibodies. ORF8b appeared not to be expressed in SARS-CoV-infected cells or when expressed from mRNA's mimicking mRNA8. This was due to the context of the internal AUG initiation codon, as we demonstrated after placing the ORF8b immediately behind the T7 promoter. A soluble, unmodified and monomeric 8b protein was now expressed in the cytoplasm, which was highly unstable and rapidly degraded. Clearly, the 29-nucleotide deletion disrupts the proper expression of the SARS-CoV ORF8, the implications of which are discussed.
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Zhao GP. SARS molecular epidemiology: a Chinese fairy tale of controlling an emerging zoonotic disease in the genomics era. Philos Trans R Soc Lond B Biol Sci 2007; 362:1063-81. [PMID: 17327210 PMCID: PMC2435571 DOI: 10.1098/rstb.2007.2034] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Severe acute respiratory syndrome (SARS) was the first natural disaster that challenged the Chinese people at the beginning of the twenty-first century. It was caused by a novel animal coronavirus, never recognized or characterized before. This SARS coronavirus (SARS-CoV) exploited opportunities provided by 'wet markets' in southern China to adapt to the palm civet and human. Under the positive selection pressure of human host, certain mutated lineages of the virus became readily transmissible between humans and thus caused the epidemic of 2002-2003. This review will provide first-hand information, particularly from Guangdong, China, about the initial epidemiology, the identification of the aetiological agent of the disease, the molecular evolution study of the virus, the finding of SARS-like CoV in horseshoe bats and the mechanistic analysis for the cross-host tropism transition. The substantial scientific contributions made by the Chinese scientists towards understanding the virus and the disease will be emphasized. Along with the description of the scientific discoveries and analyses, the significant impact of these researches upon the public health measurement or regulations will be highlighted. It is aimed to appreciate the concerted and coordinated global response that controlled SARS within a short period of time as well as the research strategy and methodology developed along with this process, which can be applied in response to other public health challenges, particularly the future emerging/re-merging infectious diseases.
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Affiliation(s)
- Guo-ping Zhao
- Laboratory of Health and Disease Genomics, Chinese National Human Genome Center at Shanghai, Building 1, 250 Bi-Bo Road, Zhangjiang HiTech Park, Pudong, Shanghai 201203, People's Republic of China.
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Shi Z, Hu Z. A review of studies on animal reservoirs of the SARS coronavirus. Virus Res 2007; 133:74-87. [PMID: 17451830 PMCID: PMC7114516 DOI: 10.1016/j.virusres.2007.03.012] [Citation(s) in RCA: 205] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2006] [Revised: 03/04/2007] [Accepted: 03/15/2007] [Indexed: 12/02/2022]
Abstract
In this review, we summarize the researches on animal reservoirs of the SARS coronavirus (SARS-CoV). Masked palm civets were suspected as the origin of the SARS outbreak in 2003 and was confirmed as the direct origin of SARS cases with mild symptom in 2004. Sequence analysis of the SARS-CoV-like virus in masked palm civets indicated that they were highly homologous to human SARS-CoV with nt identity over 99.6%, indicating the virus has not been circulating in the population of masked palm civets for a very long time. Alignment of 10 complete viral genome sequences from masked palm civets with those of human SARS-CoVs revealed 26 conserved single-nucleotide variations (SNVs) in the viruses from masked palm civets. These conserved SNVs were gradually lost from the genomes of viruses isolated from the early phase to late phase human patients of the 2003 SARS epidemic. In 2005, horseshoe bats were identified as the natural reservoir of a group of coronaviruses that are distantly related to SARS-CoV. The genome sequences of bat SARS-like coronavirus had about 88–92% nt identity with that of the SARS-CoV. The prevalence of antibodies and viral RNA in different bat species and the characteristics of the bat SARS-like coronavirus were elucidated. Apart from masked palm civets and bats, 29 other animal species had been tested for the SARS-CoV, and the results are summarized in this paper.
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Affiliation(s)
- Zhengli Shi
- State Key Laboratory of Virology and Joint-Lab of Invertebrate Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
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Tang JW, Cheung JLK, Chu IMT, Sung JJY, Peiris M, Chan PKS. The large 386-nt deletion in SARS-associated coronavirus: evidence for quasispecies? J Infect Dis 2006; 194:808-13. [PMID: 16941348 PMCID: PMC7109873 DOI: 10.1086/507044] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2006] [Accepted: 05/10/2006] [Indexed: 01/15/2023] Open
Abstract
The severe acute respiratory syndrome–associated coronavirus (SARS-CoV) is reported to have deletions of various sizes. Recently, the large 386-nucleotide deletion (L386del) comprising nucleotide positions 27719-28104 and spanning open reading frames 9–11 has been reported in the genomes of some human isolates from Hong Kong. In this study, archived specimens from 71 patients with SARS who were admitted to the New Territory East Cluster Hospitals in Hong Kong were analyzed to determine whether the L386del variant of SARS-CoV was present. There was no clear relationship between the presence of the L386del variant and SARS clinical severity as defined either by the need for intensive-care therapy and/or ventilation or by death. One patient had evidence of both the L386del variant and the wild-type variant in the same clinical specimen, supporting the idea that SARS-CoV exists as a quasispecies in some patients, although the clinical significance of these quasispecies remains unclear
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Affiliation(s)
| | | | | | - Joseph J. Y. Sung
- Medicine and Therapeutics, Centre for Emerging Infectious Diseases, and
- School of Public Health, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, and
| | - Malik Peiris
- Department of Microbiology, The University of Hong Kong, Queen Mary Hospital, Pokfulam, Hong Kong SAR, China
| | - Paul K. S. Chan
- Microbiology and
- School of Public Health, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, and
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Keng CT, Choi YW, Welkers MRA, Chan DZL, Shen S, Gee Lim S, Hong W, Tan YJ. The human severe acute respiratory syndrome coronavirus (SARS-CoV) 8b protein is distinct from its counterpart in animal SARS-CoV and down-regulates the expression of the envelope protein in infected cells. Virology 2006; 354:132-42. [PMID: 16876844 PMCID: PMC7111915 DOI: 10.1016/j.virol.2006.06.026] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2006] [Revised: 06/15/2006] [Accepted: 06/17/2006] [Indexed: 12/14/2022]
Abstract
The severe acute respiratory syndrome coronavirus (SARS-CoV), isolated from humans infected during the peak of epidemic, encodes two accessory proteins termed as 8a and 8b. Interestingly, the SARS-CoV isolated from animals contains an extra 29-nucleotide in this region such that these proteins are fused to become a single protein, 8ab. Here, we compared the cellular properties of the 8a, 8b and 8ab proteins by examining their cellular localizations and their abilities to interact with other SARS-CoV proteins. These results may suggest that the conformations of 8a and 8b are different from 8ab although nearly all the amino acids in 8a and 8b are found in 8ab. In addition, the expression of the structural protein, envelope (E), was down-regulated by 8b but not 8a or 8ab. Consequently, E was not detectable in SARS-CoV-infected cells that were expressing high levels of 8b. These findings suggest that 8b may modulate viral replication and/or pathogenesis.
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Affiliation(s)
- Choong-Tat Keng
- Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos, Singapore, 138673
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Chim SSC, Chiu RWK, Lo YMD. Genomic sequencing of the severe acute respiratory syndrome-coronavirus. Methods Mol Biol 2006; 336:177-94. [PMID: 16916263 PMCID: PMC7121524 DOI: 10.1385/1-59745-074-x:177] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2023]
Abstract
The polymerase chain reaction (PCR), which can exponentially replicate a target DNA sequence, has formed the basis for the sensitive and direct examination of clinical samples for evidence of infection. During the epidemic of severe acute respiratory syndrome (SARS) in 2003, PCR not only offered a rapid way to diagnose SARS-coronavirus (SARS-CoV) infection, but also made the molecular analysis of its genomic sequence possible. Sequence variations were observed in the SAR-CoV obtained from different patients in this epidemic. These unique viral genetic signatures can be applied as a powerful molecular tool in tracing the route of transmission and in studying the genome evolution of SARS-CoV. To extract this wealth of information from the limited primary clinical specimens of SARS patients, we were presented with the challenge of efficiently amplifying fragments of the SARS-CoV genome for analysis. In this chapter, we will discuss how we managed to accomplish this task with our optimized protocols on reverse-transcription, nested PCR amplification, and DNA cycle sequencing. We will also discuss the sequence variations that typified some strains of SARS-CoV in the different phases during this epidemic. PCR amplification of the viral sequence and genomic sequencing of these critical sequence variations of re-emerging SARS-CoV strains would give us quick insights into the virus.
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Affiliation(s)
- Stephen S C Chim
- Department of Obstetrics and Gynaecology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, SAR
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Pavlović-Lazetić GM, Mitić NS, Tomović AM, Pavlović MD, Beljanski MV. SARS-CoV genome polymorphism: a bioinformatics study. GENOMICS PROTEOMICS & BIOINFORMATICS 2005; 3:18-35. [PMID: 16144519 PMCID: PMC5172477 DOI: 10.1016/s1672-0229(05)03004-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A dataset of 103 SARS-CoV isolates (101 human patients and 2 palm civets) was investigated on different aspects of genome polymorphism and isolate classification. The number and the distribution of single nucleotide variations (SNVs) and insertions and deletions, with respect to a “profile”, were determined and discussed ("profile" being a sequence containing the most represented letter per position). Distribution of substitution categories per codon positions, as well as synonymous and non-synonymous substitutions in coding regions of annotated isolates, was determined, along with amino acid (a.a.) property changes. Similar analysis was performed for the spike (S) protein in all the isolates (55 of them being predicted for the first time). The ratio Ka/Ks confirmed that the S gene was subjected to the Darwinian selection during virus transmission from animals to humans. Isolates from the dataset were classified according to genome polymorphism and genotypes. Genome polymorphism yields to two groups, one with a small number of SNVs and another with a large number of SNVs, with up to four subgroups with respect to insertions and deletions. We identified three basic nine-locus genotypes: TTTT/TTCGG, CGCC/TTCAT, and TGCC/TTCGT, with four subgenotypes. Both classifications proposed are in accordance with the new insights into possible epidemiological spread, both in space and time.
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Chung GTY, Chiu RWK, Cheung JLK, Jin Y, Chim SSC, Chan PKS, Lo YMD. A simple and rapid approach for screening of SARS-coronavirus genotypes: an evaluation study. BMC Infect Dis 2005; 5:87. [PMID: 16229749 PMCID: PMC1276795 DOI: 10.1186/1471-2334-5-87] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2005] [Accepted: 10/18/2005] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The Severe Acute Respiratory Syndrome (SARS) was a newly emerged infectious disease which caused a global epidemic in 2002-2003. Sequence analysis of SARS-coronavirus isolates revealed that specific genotypes predominated at different periods of the epidemic. This information can be used as a footprint for tracing the epidemiology of infections and monitor viral evolution. However, direct sequencing analysis of a large number of clinical samples is cumbersome and time consuming. We present here a simple and rapid assay for the screening of SARS-coronavirus genotypes based on the use of fluorogenic oligonucleotide probes for allelic discrimination. METHODS Thirty SARS patients were recruited. Allelic discrimination assays were developed based on the use of fluorogenic oligonucleotide probes (TaqMan). Genotyping of the SARS-coronavirus isolates obtained from these patients were carried out by the allelic discrimination assays and confirmed by direct sequencing. RESULTS Genotyping based on the allelic discrimination assays were fully concordant with direct sequencing. All of the 30 SARS-coronavirus genotypes studied were characteristic of genotypes previously documented to be associated with the latter part of the epidemic. Seven of the isolates contained a previously reported major deletion but in patients not epidemiologically related to the previously studied cohort. CONCLUSION We have developed a simple and accurate method for the characterization and screening of SARS-coronavirus genotypes. It is a promising tool for the study of epidemiological relationships between documented cases during an outbreak.
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Affiliation(s)
- Grace TY Chung
- Centre for Emerging Infectious Diseases, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong
- Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong
| | - Rossa WK Chiu
- Centre for Emerging Infectious Diseases, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong
- Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong
| | - Jo LK Cheung
- Department of Microbiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong
| | - Yongjie Jin
- Centre for Emerging Infectious Diseases, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong
- Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong
| | - Stephen SC Chim
- Centre for Emerging Infectious Diseases, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong
- Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong
| | - Paul KS Chan
- Centre for Emerging Infectious Diseases, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong
- Department of Microbiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong
| | - YM Dennis Lo
- Centre for Emerging Infectious Diseases, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong
- Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong
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