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Xue L, Chang T, Li Z, Wang C, Zhao H, Li M, Tang P, Wen X, Yu M, Wu J, Bao X, Wang X, Gong P, He J, Chen X, Xiong X. Cryo-EM structures of Thogoto virus polymerase reveal unique RNA transcription and replication mechanisms among orthomyxoviruses. Nat Commun 2024; 15:4620. [PMID: 38816392 PMCID: PMC11139864 DOI: 10.1038/s41467-024-48848-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 05/13/2024] [Indexed: 06/01/2024] Open
Abstract
Influenza viruses and thogotoviruses account for most recognized orthomyxoviruses. Thogotoviruses, exemplified by Thogoto virus (THOV), are capable of infecting humans using ticks as vectors. THOV transcribes mRNA without the extraneous 5' end sequences derived from cap-snatching in influenza virus mRNA. Here, we report cryo-EM structures to characterize THOV polymerase RNA synthesis initiation and elongation. The structures demonstrate that THOV RNA transcription and replication are able to start with short dinucleotide primers and that the polymerase cap-snatching machinery is likely non-functional. Triggered by RNA synthesis, asymmetric THOV polymerase dimers can form without the involvement of host factors. We confirm that, distinctive from influenza viruses, THOV-polymerase RNA synthesis is weakly dependent of the host factors ANP32A/B/E in human cells. This study demonstrates varied mechanisms in RNA synthesis and host factor utilization among orthomyxoviruses, providing insights into the mechanisms behind thogotoviruses' broad-infectivity range.
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Affiliation(s)
- Lu Xue
- State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangdong Provincial Key Laboratory of Biocomputing, GIBH-CUHK Joint Research Laboratory on Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Tiancai Chang
- State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangdong Provincial Key Laboratory of Biocomputing, GIBH-CUHK Joint Research Laboratory on Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Zimu Li
- State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangdong Provincial Key Laboratory of Biocomputing, GIBH-CUHK Joint Research Laboratory on Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
- Guangzhou National Laboratory, Guangzhou, Guangdong, China
| | - Chenchen Wang
- College of Medicine, Southern University of Science and Technology, Shenzhen, China
| | - Heyu Zhao
- State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangdong Provincial Key Laboratory of Biocomputing, GIBH-CUHK Joint Research Laboratory on Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Mei Li
- Guangzhou National Laboratory, Guangzhou, Guangdong, China
| | - Peng Tang
- State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangdong Provincial Key Laboratory of Biocomputing, GIBH-CUHK Joint Research Laboratory on Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Xin Wen
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, Hubei, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Mengmeng Yu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Jiqin Wu
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, Hubei, China
| | - Xichen Bao
- State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangdong Provincial Key Laboratory of Biocomputing, GIBH-CUHK Joint Research Laboratory on Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Xiaojun Wang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Peng Gong
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, Hubei, China
| | - Jun He
- State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangdong Provincial Key Laboratory of Biocomputing, GIBH-CUHK Joint Research Laboratory on Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Xinwen Chen
- Guangzhou National Laboratory, Guangzhou, Guangdong, China.
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, Hubei, China.
| | - Xiaoli Xiong
- State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangdong Provincial Key Laboratory of Biocomputing, GIBH-CUHK Joint Research Laboratory on Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.
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Dupuis AP, Lange RE, Ciota AT. Emerging tickborne viruses vectored by Amblyomma americanum (Ixodida: Ixodidae): Heartland and Bourbon viruses. JOURNAL OF MEDICAL ENTOMOLOGY 2023; 60:1183-1196. [PMID: 37862097 DOI: 10.1093/jme/tjad060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 05/01/2023] [Accepted: 05/19/2023] [Indexed: 10/21/2023]
Abstract
Heartland (HRTV) and Bourbon (BRBV) viruses are newly identified tick-borne viruses, isolated from serious clinical cases in 2009 and 2014, respectively. Both viruses originated in the lower Midwest United States near the border of Missouri and Kansas, cause similar disease manifestations, and are presumably vectored by the same tick species, Amblyomma americanum Linnaeus (Ixodida: Ixodidae). In this article, we provide a current review of HRTV and BRBV, including the virology, epidemiology, and ecology of the viruses with an emphasis on the tick vector. We touch on current challenges of vector control and surveillance, and we discuss future directions in the study of these emergent pathogens.
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Affiliation(s)
- Alan P Dupuis
- Wadsworth Center, New York State Department of Health, Griffin Laboratory, 5668 State Farm Road, Slingerlands, NY 12159, USA
| | - Rachel E Lange
- Wadsworth Center, New York State Department of Health, Griffin Laboratory, 5668 State Farm Road, Slingerlands, NY 12159, USA
- Department of Biomedical Sciences, School of Public Health, State University of New York University at Albany, Rensselaer, NY 12144, USA
| | - Alexander T Ciota
- Wadsworth Center, New York State Department of Health, Griffin Laboratory, 5668 State Farm Road, Slingerlands, NY 12159, USA
- Department of Biomedical Sciences, School of Public Health, State University of New York University at Albany, Rensselaer, NY 12144, USA
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Tang Z, Hegde S, Hao S, Selvaraju M, Qiu J, Wang J. Chemical-guided SHAPE sequencing (cgSHAPE-seq) informs the binding site of RNA-degrading chimeras targeting SARS-CoV-2 5' untranslated region. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.03.535453. [PMID: 37066172 PMCID: PMC10103992 DOI: 10.1101/2023.04.03.535453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
One of the hallmarks of RNA viruses is highly structured untranslated regions (UTRs) in their genomes. These conserved RNA structures are often essential for viral replication, transcription, or translation. In this report, we discovered and optimized a new type of coumarin derivatives, such as C30 and C34, which bind to a four-way RNA helix called SL5 in the 5' UTR of the SARS-CoV-2 RNA genome. To locate the binding site, we developed a novel sequencing-based method namely cgSHAPE-seq, in which the acylating chemical probe was directed to crosslink with the 2'-OH groups of ribose at the ligand binding site. This crosslinked RNA could then create read-through mutations during reverse transcription (i.e., primer extension) at single-nucleotide resolution to uncover the acylation locations. cgSHAPE-seq unambiguously determined that a bulged G in SL5 was the primary binding site of C30 in the SARS-CoV-2 5' UTR, which was validated through mutagenesis and in vitro binding experiments. C30 was further used as a warhead in RNA-degrading chimeras to reduce viral RNA expression levels. We demonstrated that replacing the acylating moiety in the cgSHAPE probe with ribonuclease L recruiter (RLR) moieties yielded RNA degraders active in the in vitro RNase L degradation assay and SARS-CoV-2 5' UTR expressing cells. We further explored another RLR conjugation site on the E ring of C30/C34 and discovered improved RNA degradation activities in vitro and in cells. The optimized RNA-degrading chimera C64 inhibited live virus replication in lung epithelial carcinoma cells.
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Affiliation(s)
- Zhichao Tang
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS, USA
| | - Shalakha Hegde
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS, USA
| | - Siyuan Hao
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, KS, USA
| | | | - Jianming Qiu
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Jingxin Wang
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS, USA
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Wang Z, Yang L. The Therapeutic Potential of Natural Dietary Flavonoids against SARS-CoV-2 Infection. Nutrients 2023; 15:3443. [PMID: 37571380 PMCID: PMC10421531 DOI: 10.3390/nu15153443] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 07/28/2023] [Accepted: 08/02/2023] [Indexed: 08/13/2023] Open
Abstract
The exploration of non-toxic and cost-effective dietary components, such as epigallocatechin 3-gallate and myricetin, for health improvement and disease treatment has recently attracted substantial research attention. The recent COVID-19 pandemic has provided a unique opportunity for the investigation and identification of dietary components capable of treating viral infections, as well as gathering the evidence needed to address the major challenges presented by public health emergencies. Dietary components hold great potential as a starting point for further drug development for the treatment and prevention of SARS-CoV-2 infection owing to their good safety, broad-spectrum antiviral activities, and multi-organ protective capacity. Here, we review current knowledge of the characteristics-chemical composition, bioactive properties, and putative mechanisms of action-of natural bioactive dietary flavonoids with the potential for targeting SARS-CoV-2 and its variants. Notably, we present promising strategies (combination therapy, lead optimization, and drug delivery) to overcome the inherent deficiencies of natural dietary flavonoids, such as limited bioavailability and poor stability.
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Affiliation(s)
- Zhonglei Wang
- Key Laboratory of Green Natural Products and Pharmaceutical Intermediates in Colleges and Universities of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, China
- School of Pharmaceutical Sciences, Key Laboratory of Bioorganic Phosphorus, Chemistry & Chemical Biology (Ministry of Education), Tsinghua University, Beijing 100084, China
| | - Liyan Yang
- School of Physics and Physical Engineering, Qufu Normal University, Qufu 273165, China
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
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Bendl E, Fuchs J, Kochs G. Bourbon virus, a newly discovered zoonotic thogotovirus. J Gen Virol 2023; 104. [PMID: 37643129 DOI: 10.1099/jgv.0.001887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023] Open
Abstract
The recent discovery of Bourbon virus (BRBV) put a new focus on the genus of thogotoviruses as zoonotic, tick-transmitted pathogens within the orthomyxovirus family. Since 2014, BRBV has been linked to several human cases in the Midwest United States with severe acute febrile illness and a history of tick bites. The detection of the virus in the Lone Star tick, Amblyomma americanum, and a high sero-prevalence in wild animals suggest widespread circulation of BRBV. Phylogenetic analysis of the viral RNA genome classified BRBV into the subgroup of Dhori-like thogotoviruses. Strikingly, BRBV is apathogenic in mice, contrasting not only with the fatal disease in affected patients but also with the severe disease in mice caused by other members of the thogotovirus genus. To gain insights into this intriguing discrepancy, we will review the molecular biology and pathology of BRBV and its unique position within the thogotovirus genus. Lastly, we will discuss the zoonotic threat posed by this newly discovered pathogen.
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Affiliation(s)
- Elias Bendl
- Institute of Virology, Medical Center and Faculty of Medicine, University of Freiburg, Hermann-Herder-Strasse 11, 79104 Freiburg, Germany
| | - Jonas Fuchs
- Institute of Virology, Medical Center and Faculty of Medicine, University of Freiburg, Hermann-Herder-Strasse 11, 79104 Freiburg, Germany
| | - Georg Kochs
- Institute of Virology, Medical Center and Faculty of Medicine, University of Freiburg, Hermann-Herder-Strasse 11, 79104 Freiburg, Germany
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Lange RE, Dupuis AP, Ciota AT. Diversification of Bourbon Virus in New York State. Microorganisms 2023; 11:1590. [PMID: 37375092 DOI: 10.3390/microorganisms11061590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Revised: 06/08/2023] [Accepted: 06/12/2023] [Indexed: 06/29/2023] Open
Abstract
Bourbon virus (BRBV, family Orthomyxoviridae) is a tickborne virus recently detected in the United States (US). BRBV was first identified from a fatal human case in 2014 in Bourbon County, Kansas. Enhanced surveillance in Kansas and Missouri implicated Amblyomma americanum as the primary vector for BRBV. Historically, BRBV was only detected in the lower midwestern US, but since 2020 it has been reported in North Carolina, Virginia, New Jersey, and New York State (NYS). This study aimed to elucidate genetic and phenotypic characteristics of BRBV strains from NYS through whole genome sequencing and the assessment of replication kinetics in mammalian cultures and A. americanum nymphs. Sequence analysis revealed the existence of two divergent BRBV clades circulating in NYS. BRBV NY21-2143 is closely related to the midwestern BRBV strains but has unique substitutions in the glycoprotein. Two other NYS BRBV strains, BRBV NY21-1814 and BRBV NY21-2666, form a distinct clade unique from previously sequenced BRBV strains. Phenotypic diversification was also detected in NYS BRBV strains compared to each other and midwestern BRBV strains, with BRBV NY21-2143 displaying attenuation in rodent-derived cell culture and a fitness advantage in experimentally infected A. americanum. These data suggest genetic and phenotypic diversification of emergent BRBV strains circulating in NYS that could contribute to increased spread of BRBV in the northeastern US.
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Affiliation(s)
- Rachel E Lange
- Department of Biomedical Sciences, School of Public Health, University at Albany, State University of New York, 1 University Place, Rensselaer, NY 12144, USA
- Wadsworth Center, New York State Department of Health, Griffin Laboratory, 5668 State Farm Road, Slingerlands, NY 12159, USA
| | - Alan P Dupuis
- Wadsworth Center, New York State Department of Health, Griffin Laboratory, 5668 State Farm Road, Slingerlands, NY 12159, USA
| | - Alexander T Ciota
- Department of Biomedical Sciences, School of Public Health, University at Albany, State University of New York, 1 University Place, Rensselaer, NY 12144, USA
- Wadsworth Center, New York State Department of Health, Griffin Laboratory, 5668 State Farm Road, Slingerlands, NY 12159, USA
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Roe MK, Huffman ER, Batista YS, Papadeas GG, Kastelitz SR, Restivo AM, Stobart CC. Comprehensive Review of Emergence and Virology of Tickborne Bourbon Virus in the United States. Emerg Infect Dis 2023; 29:1-7. [PMID: 36573641 PMCID: PMC9796205 DOI: 10.3201/eid2901.212295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
This novel human pathogenic tickborne thogotovirus is found in the eastern and central regions of the country. The emergence of SARS-CoV-2 and the worldwide COVID-19 pandemic triggered considerable attention to the emergence and evolution of novel human pathogens. Bourbon virus (BRBV) was first discovered in 2014 in Bourbon County, Kansas, USA. Since its initial discovery, several cases of BRBV infection in humans have been identified in Kansas, Oklahoma, and Missouri. BRBV is classified within the Thogotovirus genus; these negative-strand RNA viruses appear to be transmitted by ticks, and much of their biology remains unknown. In this review, we describe the emergence, virology, geographic range and ecology, and human disease caused by BRBV and discuss potential treatments for active BRBV infections. This virus and other emerging viral pathogens remain key public health concerns and require continued surveillance and study to mitigate human exposure and disease.
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Yamaoka S, Weisend CM, Swenson VA, Ebihara H. Development of accelerated high-throughput antiviral screening systems for emerging orthomyxoviruses. Antiviral Res 2022; 200:105291. [PMID: 35296419 PMCID: PMC9259280 DOI: 10.1016/j.antiviral.2022.105291] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 03/10/2022] [Accepted: 03/12/2022] [Indexed: 11/19/2022]
Abstract
Bourbon virus (BRBV) is an emerging tick-borne orthomyxovirus that causes severe febrile illness in humans. There are no specific treatments for BRBV disease currently available. Here, we developed a highly accessible and robust, quantitative fluorescence-based BRBV minigenome (MG) system and applied it to high-throughput antiviral drug screening. We demonstrated that human dihydroorotate dehydrogenase (DHODH) inhibitors, hDHODH-IN-4 and brequinar, efficiently reduced BRBV RNA synthesis, and validated these findings using infectious BRBV in vitro. The DHODH inhibitors also exhibited high potency in inhibiting MG activities of other orthomyxoviruses with emerging zoonotic potential, including bat influenza A virus, swine influenza D virus, and Thogoto virus. Our newly developed MG system is a powerful platform for antiviral drug screening across the Orthomyxoviridae family, enabling rapid development and deployment of antivirals against future emerging orthomyxoviruses.
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Affiliation(s)
- Satoko Yamaoka
- Mayo Clinic, Department of Infectious Diseases, Rochester, MN, 55905, USA
| | - Carla M Weisend
- Mayo Clinic, Department of Infectious Diseases, Rochester, MN, 55905, USA; Mayo Clinic, Department of Molecular Medicine, Rochester, MN, 55905, USA
| | - Vaille A Swenson
- Mayo Clinic Graduate School of Biomedical Sciences, Virology and Gene Therapy Graduate Program, Rochester, MN, 55905, USA
| | - Hideki Ebihara
- National Institute of Infectious Diseases, Department of Virology I, Tokyo, 162-8640, Japan.
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Hao S, Ning K, Küz ÇA, McFarlin S, Cheng F, Qiu J. Eight years' advances on Bourbon virus, a tick-born Thogotovirus of the Orthomyxovirus family. ZOONOSES (BURLINGTON, MASS.) 2022; 2:18. [PMID: 35727718 PMCID: PMC9206863 DOI: 10.15212/zoonoses-2022-0012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Bourbon virus (BRBV) was first isolated from a blood sample collected from a male patient living in Bourbon county, Kansas, during the spring of 2014. The patient later died due to complications associated with multiorgan failure. Currently, several BRBV infection-caused deaths have been reported in the United States, and misdiagnosed cases are often undercounted. BRBV is a member of the genus Thogotovirus of the Orthomyxoviridae family, and is transmitted through the Lone Star tick, Amblyomma Americanum, in North America. Currently, there are no specific antivirals or vaccinations available to treat or prevent BRBV infection. Several small molecular compounds have been identified to effectively inhibit BRBV infection of in vitro cell cultures at a single- or sub-micromolar level. Favipiravir, an RNA-dependent RNA polymerase inhibitor, prevented the death of Type I interferon receptor knockout mice infected with BRBV infection.
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Affiliation(s)
| | | | | | | | | | - Jianming Qiu
- Corresponding author: Jianming Qiu, Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Mail Stop 3029, 3901 Rainbow Blvd. Kansas City, KS 66160, Phone: (913) 588-4329, Fax: (913) 588-7295,
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The N-terminal 5-68 amino acids domain of the minor capsid protein VP1 of human parvovirus B19 enters human erythroid progenitors and inhibits B19 infection. J Virol 2021; 95:JVI.00466-21. [PMID: 33952637 PMCID: PMC8223926 DOI: 10.1128/jvi.00466-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Parvovirus B19 (B19V) infection causes diseases in humans ranging from the mild erythema infectiosum to severe hematological disorders. The unique region of the minor structural protein VP1 (VP1u) of 227 amino acids harbors strong neutralizing epitopes which elicit dominant immune responses in patients. Recent studies have shown that the VP1u selectively binds to and enters B19V permissive cells through an unknown cellular proteinaceous receptor. In the present study, we demonstrated that purified recombinant VP1u effectively inhibits B19V infection of ex vivo expanded primary human erythroid progenitors. Furthermore, we identified the amino acid sequence 5-68 of the VP1 (VP1u5-68aa) is sufficient to confer the inhibition of B19V infection at a level similar to that of the full-length VP1u. In silico structure prediction suggests that the VP1u5-68aa contains three α-helices. Importantly, we found that the inhibition capability of the minimal domain VP1u5-68aa is independent of its dimerization but is likely dependent on the structure of the three predicated α-helices. As VP1u5-68aa outcompetes the full-length VP1u in entering cells, we believe that VP1u5-68aa functions as a receptor-binding ligand during virus entry. Finally, we determined the effective inhibition potency of VP1u5-68aa in B19V infection of human erythroid progenitors, which has a half maximal effective concentration (EC50) of 67 nM, suggesting an anti-viral peptide candidate to combat B19V infection.IMPORTANCEHuman parvovirus B19 infection causes severe hematological disorders, including transient aplastic crisis, pure red cell aplasia, and hydrops fetalis. A productive B19 infection is highly restricted to human erythroid progenitors in human bone marrow and fetal liver. In the current study, we identified that the N-terminal 5-68 amino acids domain of the minor viral capsid protein VP1 enters ex vivo expanded human erythroid progenitors, which is nearly 5 times more efficient than the full-length VP1 unique region (1-227aa). Importantly, purified recombinant 5-68aa of the VP1 has a high efficiency in inhibition of parvovirus B19 infection of human erythroid progenitors, which has a half maximal effective concentration (EC50) of 67 nM and a low cytotoxicity. The N-terminal 5-68 amino acids holds the potential as an effective antiviral of parvovirus B19 caused hematological disorders, as well as a carrier to deliver proteins to human erythroid progenitors.
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Hao S, Ning K, Kuz CA, Vorhies K, Yan Z, Qiu J. Long-Term Modeling of SARS-CoV-2 Infection of In Vitro Cultured Polarized Human Airway Epithelium. mBio 2020; 11:e02852-20. [PMID: 33158999 PMCID: PMC7649230 DOI: 10.1128/mbio.02852-20] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 10/16/2020] [Indexed: 12/28/2022] Open
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replicates throughout human airways. The polarized human airway epithelium (HAE) cultured at an airway-liquid interface (HAE-ALI) is an in vitro model mimicking the in vivo human mucociliary airway epithelium and supports the replication of SARS-CoV-2. Prior studies characterized only short-period SARS-CoV-2 infection in HAE. In this study, continuously monitoring the SARS-CoV-2 infection in HAE-ALI cultures for a long period of up to 51 days revealed that SARS-CoV-2 infection was long lasting with recurrent replication peaks appearing between an interval of approximately 7 to 10 days, which was consistent in all the tested HAE-ALI cultures derived from 4 lung bronchi of independent donors. We also identified that SARS-CoV-2 does not infect HAE from the basolateral side, and the dominant SARS-CoV-2 permissive epithelial cells are ciliated cells and goblet cells, whereas virus replication in basal cells and club cells was not detected. Notably, virus infection immediately damaged the HAE, which is demonstrated by dispersed zonula occludens-1 (ZO-1) expression without clear tight junctions and partial loss of cilia. Importantly, we identified that SARS-CoV-2 productive infection of HAE requires a high viral load of >2.5 × 105 virions per cm2 of epithelium. Thus, our studies highlight the importance of a high viral load and that epithelial renewal initiates and maintains a recurrent infection of HAE with SARS-CoV-2.IMPORTANCE The pandemic of coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has led to >35 million confirmed cases and >1 million fatalities worldwide. SARS-CoV-2 mainly replicates in human airway epithelia in COVID-19 patients. In this study, we used in vitro cultures of polarized human bronchial airway epithelium to model SARS-CoV-2 replication for a period of 21 to 51 days. We discovered that in vitro airway epithelial cultures endure a long-lasting SARS-CoV-2 propagation with recurrent peaks of progeny virus release at an interval of approximately 7 to 10 days. Our study also revealed that SARS-CoV-2 infection causes airway epithelia damage with disruption of tight junction function and loss of cilia. Importantly, SARS-CoV-2 exhibits a polarity of infection in airway epithelium only from the apical membrane; it infects ciliated and goblet cells but not basal and club cells. Furthermore, the productive infection of SARS-CoV-2 requires a high viral load of over 2.5 × 105 virions per cm2 of epithelium. Our study highlights that the proliferation of airway basal cells and regeneration of airway epithelium may contribute to the recurrent infections.
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Affiliation(s)
- Siyuan Hao
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Kang Ning
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Cagla Aksu Kuz
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Kai Vorhies
- Department of Anatomy and Cell Biology, University of Iowa, Iowa City, Iowa, USA
| | - Ziying Yan
- Department of Anatomy and Cell Biology, University of Iowa, Iowa City, Iowa, USA
| | - Jianming Qiu
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas, USA
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