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Schindewolf C, Menachery VD. Coronavirus 2'-O-methyltransferase: A promising therapeutic target. Virus Res 2023; 336:199211. [PMID: 37634741 PMCID: PMC10485632 DOI: 10.1016/j.virusres.2023.199211] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 08/22/2023] [Accepted: 08/24/2023] [Indexed: 08/29/2023]
Abstract
Coronaviruses (CoVs) have been the source of multiple epidemics and a global pandemic since the start of century, and there is an urgent need to understand CoV biology and develop better therapeutics. Here, we review the role of NSP16 in CoV replication, specifically its importance to 2'-O-methylation and CoV RNA capping. We describe the attenuation phenotypes of NSP16-mutant CoVs, the roles of MDA5 and IFITs in sensing and antagonizing viral RNA lacking 2'O methylation, and the dependence on 2'-O-methylation in other virus families. We also detail the growing body of research into targeting 2'-O-methylation for therapeutics or as a platform for live attenuated vaccines. Beyond its role in RNA capping, NSP16 may have yet uncharacterized importance to CoV replication, highlighting the need for continued studies into NSP16 functions. Understanding the full contribution of NSP16 to the replicative fitness of CoVs will better inform the development of treatments against future CoV outbreaks.
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Affiliation(s)
- Craig Schindewolf
- Center for Immunity and Immunotherapies, Seattle Children's Research Institute, Seattle, WA, USA; Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, USA; Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, USA
| | - Vineet D Menachery
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, USA; Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, USA; World Reference Center for Emerging Viruses and Arboviruses, University of Texas Medical Branch, Galveston, TX, USA.
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2
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Wahaab A, Mustafa BE, Hameed M, Stevenson NJ, Anwar MN, Liu K, Wei J, Qiu Y, Ma Z. Potential Role of Flavivirus NS2B-NS3 Proteases in Viral Pathogenesis and Anti-flavivirus Drug Discovery Employing Animal Cells and Models: A Review. Viruses 2021; 14:44. [PMID: 35062249 PMCID: PMC8781031 DOI: 10.3390/v14010044] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 12/22/2021] [Accepted: 12/23/2021] [Indexed: 02/07/2023] Open
Abstract
Flaviviruses are known to cause a variety of diseases in humans in different parts of the world. There are very limited numbers of antivirals to combat flavivirus infection, and therefore new drug targets must be explored. The flavivirus NS2B-NS3 proteases are responsible for the cleavage of the flavivirus polyprotein, which is necessary for productive viral infection and for causing clinical infections; therefore, they are a promising drug target for devising novel drugs against different flaviviruses. This review highlights the structural details of the NS2B-NS3 proteases of different flaviviruses, and also describes potential antiviral drugs that can interfere with the viral protease activity, as determined by various studies. Moreover, optimized in vitro reaction conditions for studying the NS2B-NS3 proteases of different flaviviruses may vary and have been incorporated in this review. The increasing availability of the in silico and crystallographic/structural details of flavivirus NS2B-NS3 proteases in free and drug-bound states can pave the path for the development of promising antiflavivirus drugs to be used in clinics. However, there is a paucity of information available on using animal cells and models for studying flavivirus NS2B-NS3 proteases, as well as on the testing of the antiviral drug efficacy against NS2B-NS3 proteases. Therefore, on the basis of recent studies, an effort has also been made to propose potential cellular and animal models for the study of flavivirus NS2B-NS3 proteases for the purposes of exploring flavivirus pathogenesis and for testing the efficacy of possible drugs targets, in vitro and in vivo.
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Affiliation(s)
- Abdul Wahaab
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai 200241, China; (A.W.); (M.H.); (M.N.A.); (K.L.); (J.W.)
| | - Bahar E Mustafa
- Sub Campus Toba Tek Singh, University of Agriculture, Faisalabad 36050, Pakistan;
| | - Muddassar Hameed
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai 200241, China; (A.W.); (M.H.); (M.N.A.); (K.L.); (J.W.)
- Department of Biomedical Sciences and Pathobiology, College of Veterinary Medicine, Virginia Polytechnic Institute, State University, Fralin Life Sciences Building, 360 W Campus Blacksburg, Blacksburg, VA 24061, USA
| | - Nigel J. Stevenson
- Royal College of Surgeons in Ireland, Medical University of Bahrain, Busaiteen, Adliya 15503, Bahrain;
- Viral Immunology Group, School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, D02 R590 Dublin, Ireland
| | - Muhammad Naveed Anwar
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai 200241, China; (A.W.); (M.H.); (M.N.A.); (K.L.); (J.W.)
| | - Ke Liu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai 200241, China; (A.W.); (M.H.); (M.N.A.); (K.L.); (J.W.)
| | - Jianchao Wei
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai 200241, China; (A.W.); (M.H.); (M.N.A.); (K.L.); (J.W.)
| | - Yafeng Qiu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai 200241, China; (A.W.); (M.H.); (M.N.A.); (K.L.); (J.W.)
| | - Zhiyong Ma
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai 200241, China; (A.W.); (M.H.); (M.N.A.); (K.L.); (J.W.)
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3
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Mutations in the Methyltransferase Motifs of L Protein Attenuate Newcastle Disease Virus by Regulating Viral Translation and Cell-to-Cell Spread. Microbiol Spectr 2021; 9:e0131221. [PMID: 34585949 PMCID: PMC8557825 DOI: 10.1128/spectrum.01312-21] [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] [Indexed: 01/16/2023] Open
Abstract
The large (L) polymerase proteins of most nonsegmented, negative-stranded (NNS) RNA viruses have conserved methyltransferase motifs, (G)-G-G-D and K-D-K-E, which are important for the stabilization and translation of mRNA. However, the function of the (G)-G-G-D and K-D-K-E motifs in the NNS RNA virus Newcastle disease virus (NDV) remains unclear. We observed G-G-D and K-D-K-E motifs in all NDV genotypes. By using the infection cloning system of NDV rSG10 strain, recombinant NDVs with a single amino acid mutated to alanine in one motif (G-G-D or K-D-K-E) were rescued. The intracerebral pathogenicity index and mean death time assay results revealed that the G-G-D motif and K-D-K-E motif attenuate the virulence of NDV to various degrees. The replication, transcription, and translation levels of the K-D-K-E motif-mutant strains were significantly higher than those of wild-type virus owing to their altered regulation of the affinity between nucleocapsid protein and eukaryotic translation initiation factor 4E. When the infection dose was changed from a multiplicity of infection (MOI) of 10 to an MOI of 0.01, the cell-to-cell spread abilities of G-G-D- and K-D-K-E-mutant strains were reduced, according to plaque assay and dynamic indirect immunofluorescence assay results. Finally, we found that NDV strains with G-G-D or K-D-K-E motif mutations had less pathogenicity in 3-week-old specific-pathogen-free chickens than wild-type NDV. Therefore, these methyltransferase motifs can affect virulence by regulating the translation and cell-to-cell spread abilities of NDV. This work provides a feasible approach for generating vaccine candidates for viruses with methyltransferase motifs. IMPORTANCE Newcastle disease virus (NDV) is an important pathogen that is widespread globally. Research on its pathogenic mechanism is an important means of improving prevention and control efforts. Our study found that a deficiency in its methyltransferase motifs (G-G-D and K-D-K-E motifs) can attenuate NDV and revealed the molecular mechanism by which these motifs affect pathogenicity, which provides a new direction for the development of NDV vaccines. In addition to the (G)-G-G-D and K-D-K-E motifs of many nonsegmented, negative-stranded RNA viruses, similar motifs have been found in dengue virus, Zika virus, Japanese encephalitis virus (JEV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This suggests that such motifs may be present in more viruses. Our finding also provides a molecular basis for the discovery and functional study of (G)-G-G-D and K-D-K-E motifs of other viruses.
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Lu M, Zhang Y, Dravid P, Li A, Zeng C, KC M, Trivedi S, Sharma H, Chaiwatpongsakorn S, Zani A, Kenney A, Cai C, Ye C, Liang X, Qiu J, Martinez-Sobrido L, Yount JS, Boyaka PN, Liu SL, Peeples ME, Kapoor A, Li J. A Methyltransferase-Defective Vesicular Stomatitis Virus-Based SARS-CoV-2 Vaccine Candidate Provides Complete Protection against SARS-CoV-2 Infection in Hamsters. J Virol 2021; 95:e0059221. [PMID: 34379509 PMCID: PMC8475528 DOI: 10.1128/jvi.00592-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 08/02/2021] [Indexed: 01/11/2023] Open
Abstract
The current pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to dramatic economic and health burdens. Although the worldwide SARS-CoV-2 vaccination campaign has begun, exploration of other vaccine candidates is needed due to uncertainties with the current approved vaccines, such as durability of protection, cross-protection against variant strains, and costs of long-term production and storage. In this study, we developed a methyltransferase-defective recombinant vesicular stomatitis virus (mtdVSV)-based SARS-CoV-2 vaccine candidate. We generated mtdVSVs expressing SARS-CoV-2 full-length spike (S) protein, S1, or its receptor-binding domain (RBD). All of these recombinant viruses grew to high titers in mammalian cells despite high attenuation in cell culture. The SARS-CoV-2 S protein and its truncations were highly expressed by the mtdVSV vector. These mtdVSV-based vaccine candidates were completely attenuated in both immunocompetent and immunocompromised mice. Among these constructs, mtdVSV-S induced high levels of SARS-CoV-2-specific neutralizing antibodies (NAbs) and Th1-biased T-cell immune responses in mice. In Syrian golden hamsters, the serum levels of SARS-CoV-2-specific NAbs triggered by mtdVSV-S were higher than the levels of NAbs in convalescent plasma from recovered COVID-19 patients. In addition, hamsters immunized with mtdVSV-S were completely protected against SARS-CoV-2 replication in lung and nasal turbinate tissues, cytokine storm, and lung pathology. Collectively, our data demonstrate that mtdVSV expressing SARS-CoV-2 S protein is a safe and highly efficacious vaccine candidate against SARS-CoV-2 infection. IMPORTANCE Viral mRNA cap methyltransferase (MTase) is essential for mRNA stability, protein translation, and innate immune evasion. Thus, viral mRNA cap MTase activity is an excellent target for development of live attenuated or live vectored vaccine candidates. Here, we developed a panel of MTase-defective recombinant vesicular stomatitis virus (mtdVSV)-based SARS-CoV-2 vaccine candidates expressing full-length S, S1, or several versions of the RBD. These mtdVSV-based vaccine candidates grew to high titers in cell culture and were completely attenuated in both immunocompetent and immunocompromised mice. Among these vaccine candidates, mtdVSV-S induces high levels of SARS-CoV-2-specific neutralizing antibodies (Nabs) and Th1-biased immune responses in mice. Syrian golden hamsters immunized with mtdVSV-S triggered SARS-CoV-2-specific NAbs at higher levels than those in convalescent plasma from recovered COVID-19 patients. Furthermore, hamsters immunized with mtdVSV-S were completely protected against SARS-CoV-2 challenge. Thus, mtdVSV is a safe and highly effective vector to deliver SARS-CoV-2 vaccine.
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Affiliation(s)
- Mijia Lu
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, USA
| | - Yuexiu Zhang
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, USA
| | - Piyush Dravid
- Center for Vaccines and Immunity, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, Ohio, USA
| | - Anzhong Li
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, USA
| | - Cong Zeng
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, USA
| | - Mahesh KC
- Center for Vaccines and Immunity, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, Ohio, USA
| | - Sheetal Trivedi
- Center for Vaccines and Immunity, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, Ohio, USA
| | - Himanshu Sharma
- Center for Vaccines and Immunity, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, Ohio, USA
| | - Supranee Chaiwatpongsakorn
- Center for Vaccines and Immunity, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, Ohio, USA
| | - Ashley Zani
- Department of Microbial Infection and Immunity, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Adam Kenney
- Department of Microbial Infection and Immunity, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Chuanxi Cai
- Department of Surgery, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Chengjin Ye
- Texas Biomedical Research Institute, San Antonio, Texas, USA
| | - Xueya Liang
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, USA
| | - Jianming Qiu
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | | | - Jacob S. Yount
- Department of Microbial Infection and Immunity, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Prosper N. Boyaka
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, USA
- Infectious Disease Institute, The Ohio State University, Columbus, Ohio, USA
| | - Shan-Lu Liu
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, USA
- Department of Microbial Infection and Immunity, College of Medicine, The Ohio State University, Columbus, Ohio, USA
- Center for Retrovirus Research, The Ohio State University, Columbus, Ohio, USA
- Infectious Disease Institute, The Ohio State University, Columbus, Ohio, USA
| | - Mark E. Peeples
- Center for Vaccines and Immunity, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, Ohio, USA
- Department of Pediatrics, College of Medicine, The Ohio State University, Columbus, Ohio, USA
- Infectious Disease Institute, The Ohio State University, Columbus, Ohio, USA
| | - Amit Kapoor
- Center for Vaccines and Immunity, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, Ohio, USA
- Department of Pediatrics, College of Medicine, The Ohio State University, Columbus, Ohio, USA
- Infectious Disease Institute, The Ohio State University, Columbus, Ohio, USA
| | - Jianrong Li
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, USA
- Infectious Disease Institute, The Ohio State University, Columbus, Ohio, USA
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Sutto-Ortiz P, Tcherniuk S, Ysebaert N, Abeywickrema P, Noël M, Decombe A, Debart F, Vasseur JJ, Canard B, Roymans D, Rigaux P, Eléouët JF, Decroly E. The methyltransferase domain of the Respiratory Syncytial Virus L protein catalyzes cap N7 and 2'-O-methylation. PLoS Pathog 2021; 17:e1009562. [PMID: 33956914 PMCID: PMC8130918 DOI: 10.1371/journal.ppat.1009562] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 05/18/2021] [Accepted: 04/15/2021] [Indexed: 12/15/2022] Open
Abstract
Respiratory syncytial virus (RSV) is a negative sense single-stranded RNA virus and one of the main causes of severe lower respiratory tract infections in infants and young children. RSV RNA replication/transcription and capping are ensured by the viral Large (L) protein. The L protein contains a polymerase domain associated with a polyribonucleotidyl transferase domain in its N-terminus, and a methyltransferase (MTase) domain followed by the C-terminal domain (CTD) enriched in basic amino acids at its C-terminus. The MTase-CTD of Mononegavirales forms a clamp to accommodate RNA that is subsequently methylated on the cap structure and depending on the virus, on internal positions. These enzymatic activities are essential for efficient viral mRNA translation into proteins, and to prevent the recognition of uncapped viral RNA by innate immunity sensors. In this work, we demonstrated that the MTase-CTD of RSV, as well as the full-length L protein in complex with phosphoprotein (P), catalyzes the N7- and 2’-O-methylation of the cap structure of a short RNA sequence that corresponds to the 5’ end of viral mRNA. Using different experimental systems, we showed that the RSV MTase-CTD methylates the cap structure with a preference for N7-methylation as first reaction. However, we did not observe cap-independent internal methylation, as recently evidenced for the Ebola virus MTase. We also found that at μM concentrations, sinefungin, a S-adenosylmethionine analogue, inhibits the MTase activity of the RSV L protein and of the MTase-CTD domain. Altogether, these results suggest that the RSV MTase domain specifically recognizes viral RNA decorated by a cap structure and catalyzes its methylation, which is required for translation and innate immune system subversion. Respiratory syncytial virus (RSV) is responsible of infant bronchiolitis and severe lower respiratory tract infections in infants and young children, and the leading cause of hospitalization in children under one year of age. However, we still lack a vaccine and therapeutics against this important pathogen. The main enzymatic activities involved in RSV propagation are embedded in the Large (L) protein that contains the polymerase domain and also all the activities required for RNA cap structure synthesis and methylation. These post-transcriptional RNA modifications play a key role in virus replication because cap N7-methylation is required for viral RNA translation into proteins, and 2’-O-methylation hides viral RNA from innate immunity detection. Viral methyltransferase (MTase) activities are now considered potential antiviral targets because their inhibition might limit the virus production and strengthen early virus detection by innate immunity sensors. In this work, we compared the enzymatic activities of the MTase expressed as a single domain or in the context of the full-length L protein. We demonstrated that the MTase protein catalyzes the specific methylation of the cap structure at both N7- and 2’-O-positions, and we obtained the proof of concept that a S-adenosylmethionine analogue can inhibit the MTase activity of the L protein.
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Affiliation(s)
| | - Sergey Tcherniuk
- Unité de Virologie et Immunologie Moléculaires, INRAE, Université Paris Saclay, Jouy en Josas, France
| | - Nina Ysebaert
- Janssen Infectious Diseases and Vaccines, Beerse, Belgium
| | | | - Mathieu Noël
- IBMM, Université de Montpellier, ENSCM, CNRS, UMR 5247, Montpellier, France
| | - Alice Decombe
- Aix Marseille Université, CNRS, AFMB UMR 7257, Marseille, France
| | - Françoise Debart
- IBMM, Université de Montpellier, ENSCM, CNRS, UMR 5247, Montpellier, France
| | | | - Bruno Canard
- Aix Marseille Université, CNRS, AFMB UMR 7257, Marseille, France
| | - Dirk Roymans
- Janssen Infectious Diseases and Vaccines, Beerse, Belgium
| | - Peter Rigaux
- Janssen Infectious Diseases and Vaccines, Beerse, Belgium
| | - Jean-François Eléouët
- Unité de Virologie et Immunologie Moléculaires, INRAE, Université Paris Saclay, Jouy en Josas, France
| | - Etienne Decroly
- Aix Marseille Université, CNRS, AFMB UMR 7257, Marseille, France
- * E-mail:
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Zhu M, Wang Y, Qu C, Liu R, Zhang C, Wang J, Zhou D, Gu W, Chen P, Wu B, Zhao Z. Recombinant Chinese Hu191 measles virus exhibits a significant antitumor activity against nephroblastoma mediated by immunogenic form of apoptosis. Am J Transl Res 2021; 13:2077-2093. [PMID: 34017376 PMCID: PMC8129391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 02/02/2021] [Indexed: 06/12/2023]
Abstract
In previous studies oncolytic measles viruses (MVs) have shown significant antitumor activity against various tumors. In our research recombinant MV-Hu191 (rMV-Hu191), established via reverse genetics technology and expressing enhanced green fluorescent protein (EGFP), was evaluated for its therapeutic effects and related mechanisms against nephroblastoma cell lines. We built three different constructs based on rMV-Hu191 to express EGFP effectively. Our experiments showed that rMV-Hu191 expressing EGFP could efficiently infect and replicate in nephroblastoma cell lines. Caspase-induced apoptosis exerted a significant impact on MV-induced cell death, which was accompanied by emission of cellular ATP and high-mobility group protein 1 (HMGB1) and by translocation of calreticulin (CRT). Intratumoral injection of rMV-Hu191-EGFP resulted in significant regression of tumors in a G401 xenograft model. Our results indicate that the MV-Hu191 strain, which is widely used in China, is an appropriate vector for expression of foreign genes and could serve as a potentially good candidate for nephroblastoma therapy mediated by induction of apoptosis-associated immunogenic cell death (ICD).
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Affiliation(s)
- Mengying Zhu
- Zhejiang University School of MedicineHangzhou, Zhejiang, China
| | - Yilong Wang
- Children’s Hospital, Zhejiang University School of MedicineHangzhou 310052, Zhejiang, China
- Department of Neurology, Children’s Hospital, Zhejiang University School of MedicineHangzhou 310052, Zhejiang, China
- Children’s Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child HealthHangzhou 310052, Zhejiang, China
| | - Chufan Qu
- Zhejiang University School of MedicineHangzhou, Zhejiang, China
| | - Rongxian Liu
- Zhejiang University School of MedicineHangzhou, Zhejiang, China
| | - Chudi Zhang
- Zhejiang University School of MedicineHangzhou, Zhejiang, China
| | - Jinhu Wang
- Children’s Hospital, Zhejiang University School of MedicineHangzhou 310052, Zhejiang, China
- Children’s Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child HealthHangzhou 310052, Zhejiang, China
| | - Dongming Zhou
- Children’s Hospital, Zhejiang University School of MedicineHangzhou 310052, Zhejiang, China
- Department of Neurology, Children’s Hospital, Zhejiang University School of MedicineHangzhou 310052, Zhejiang, China
| | - Weizhong Gu
- Children’s Hospital, Zhejiang University School of MedicineHangzhou 310052, Zhejiang, China
- Department of Neurology, Children’s Hospital, Zhejiang University School of MedicineHangzhou 310052, Zhejiang, China
| | - Peichun Chen
- Maternal and Child Health Hospital of Guangming DistrictShenzhen 518000, Guangdong, China
| | - Benqing Wu
- Maternal and Child Health Hospital of Guangming DistrictShenzhen 518000, Guangdong, China
| | - Zhengyan Zhao
- Zhejiang University School of MedicineHangzhou, Zhejiang, China
- Children’s Hospital, Zhejiang University School of MedicineHangzhou 310052, Zhejiang, China
- Children’s Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child HealthHangzhou 310052, Zhejiang, China
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Jenkins T, Wang R, Harder O, Xue M, Chen P, Corry J, Walker C, Teng M, Mejias A, Ramilo O, Niewiesk S, Li J, Peeples ME. A Novel Live Attenuated Respiratory Syncytial Virus Vaccine Candidate with Mutations in the L Protein SAM Binding Site and the G Protein Cleavage Site Is Protective in Cotton Rats and a Rhesus Macaque. J Virol 2021; 95:e01568-20. [PMID: 33177201 PMCID: PMC7925107 DOI: 10.1128/jvi.01568-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 11/06/2020] [Indexed: 11/20/2022] Open
Abstract
Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory tract infections in children of <5 years of age worldwide, infecting the majority of infants in their first year of life. Despite the widespread impact of this virus, no vaccine is currently available. For more than 50 years, live attenuated vaccines (LAVs) have been shown to protect against other childhood viral infections, offering the advantage of presenting all viral proteins to the immune system for stimulation of both B and T cell responses and memory. The RSV LAV candidate described here, rgRSV-L(G1857A)-G(L208A), contains two modifications: an attenuating mutation in the S-adenosylmethionine (SAM) binding site of the viral mRNA cap methyltransferase (MTase) within the large (L) polymerase protein and a mutation in the attachment (G) glycoprotein that inhibits its cleavage during production in Vero cells, resulting in virus with a "noncleaved G" (ncG). RSV virions containing the ncG have an increased ability to infect primary well-differentiated human bronchial epithelial (HBE) cultures which model the in vivo site of immunization, the ciliated airway epithelium. This RSV LAV candidate is produced efficiently in Vero cells, is highly attenuated in HBE cultures, efficiently induces neutralizing antibodies that are long lasting, and provides protection against an RSV challenge in the cotton rat, without causing enhanced disease. Similar results were obtained in a rhesus macaque.IMPORTANCE Globally, respiratory syncytial virus (RSV) is a major cause of death in children under 1 year of age, yet no vaccine is available. We have generated a novel RSV live attenuated vaccine candidate containing mutations in the L and G proteins. The L polymerase mutation does not inhibit virus yield in Vero cells, the cell type required for vaccine production, but greatly reduces virus spread in human bronchial epithelial (HBE) cultures, a logical in vitro predictor of in vivo attenuation. The G attachment protein mutation reduces its cleavage in Vero cells, thereby increasing vaccine virus yield, making vaccine production more economical. In cotton rats, this RSV vaccine candidate is highly attenuated at a dose of 105 PFU and completely protective following immunization with 500 PFU, 200-fold less than the dose usually used in such studies. It also induced long-lasting antibodies in cotton rats and protected a rhesus macaque from RSV challenge. This mutant virus is an excellent RSV live attenuated vaccine candidate.
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Affiliation(s)
- Tiffany Jenkins
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, USA
- Center for Vaccines and Immunity, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Rongzhang Wang
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Olivia Harder
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Miaoge Xue
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Phylip Chen
- Center for Vaccines and Immunity, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Jacqueline Corry
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Christopher Walker
- Center for Vaccines and Immunity, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Michael Teng
- Department of Internal Medicine, University of South Florida Morsani College of Medicine, Tampa, Florida, USA
| | - Asuncion Mejias
- Center for Vaccines and Immunity, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Octavio Ramilo
- Center for Vaccines and Immunity, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Stefan Niewiesk
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Jianrong Li
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Mark E Peeples
- Center for Vaccines and Immunity, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio, USA
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Development of Improved Mumps Vaccine Candidates by Mutating Viral mRNA Cap Methyltransferase Sites in the Large Polymerase Protein. Virol Sin 2020; 36:521-536. [PMID: 33284397 PMCID: PMC7719854 DOI: 10.1007/s12250-020-00326-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Accepted: 10/20/2020] [Indexed: 10/26/2022] Open
Abstract
Although a live attenuated vaccine is available for controlling mumps virus (MuV), mumps still outbreaks frequently worldwide. The attenuated MuV vaccine strain S79 is widely used in mumps vaccination in China, but still with many shortcomings, among which the most prominent are the side effects and decreased immunity. Therefore, there is a need to further improve the safety and efficacy of the current MuV vaccine. In the present study, we further attenuated MuV S79 vaccine strain by inhibiting viral mRNA methyltransferase (MTase). We generated a panel of eight recombinant MuVs (rMuVs) carrying mutations in the MTase catalytic site or S-adenosylmethionine (SAM) binding site in the large (L) polymerase protein. These rMuVs are genetically stable and seven rMuVs are more attenuated in replication in cell culture and five rMuVs are more attenuated in replication in lungs of cotton rats compared with the parental vaccine strain S79. Importantly, cotton rats vaccinated with these seven rMuV mutants produced high levels of serum neutralizing antibodies and were completely protected against challenge with a wild-type MuV strain (genotype F). Therefore, our results demonstrate that alteration in the MTase catalytic site or SAM binding site in MuV L protein improves the safety or the immunogenicity of the MuV vaccine and thus mRNA cap MTase may be an effective target for the development of new vaccine candidates for MuV.
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9
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Abstract
Chemical modifications of viral RNA are an integral part of the viral life cycle and are present in most classes of viruses. To date, more than 170 RNA modifications have been discovered in all types of cellular RNA. Only a few, however, have been found in viral RNA, and the function of most of these has yet to be elucidated. Those few we have discovered and whose functions we understand have a varied effect on each virus. They facilitate RNA export from the nucleus, aid in viral protein synthesis, recruit host enzymes, and even interact with the host immune machinery. The most common methods for their study are mass spectrometry and antibody assays linked to next-generation sequencing. However, given that the actual amount of modified RNA can be very small, it is important to pair meticulous scientific methodology with the appropriate detection methods and to interpret the results with a grain of salt. Once discovered, RNA modifications enhance our understanding of viruses and present a potential target in combating them. This review provides a summary of the currently known chemical modifications of viral RNA, the effects they have on viral machinery, and the methods used to detect them.
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Affiliation(s)
- Jiří František Potužník
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czech Republic
| | - Hana Cahová
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czech Republic
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10
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Porcine Epidemic Diarrhea Virus Deficient in RNA Cap Guanine-N-7 Methylation Is Attenuated and Induces Higher Type I and III Interferon Responses. J Virol 2020; 94:JVI.00447-20. [PMID: 32461321 DOI: 10.1128/jvi.00447-20] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 05/16/2020] [Indexed: 12/23/2022] Open
Abstract
The 5' cap methylation of viral RNA plays important roles in RNA stability, efficient translation, and immune evasion. Thus, RNA cap methylation is an attractive target for antiviral discovery and development of new live attenuated vaccines. For coronaviruses, RNA cap structure is first methylated at the guanine-N-7 (G-N-7) position by nonstructural protein 14 (nsp14), which facilitates and precedes the subsequent ribose 2'-O methylation by the nsp16-nsp10 complex. Using porcine epidemic diarrhea virus (PEDV), an Alphacoronavirus, as a model, we showed that G-N-7 methyltransferase (G-N-7 MTase) of PEDV nsp14 methylated RNA substrates in a sequence-unspecific manner. PEDV nsp14 can efficiently methylate RNA substrates with various lengths in both neutral and alkaline pH environments and can methylate cap analogs (GpppA and GpppG) and single-nucleotide GTP but not ATP, CTP, or UTP. Mutations to the S-adenosyl-l-methionine (SAM) binding motif in the nsp14 abolished the G-N-7 MTase activity and were lethal to PEDV. However, recombinant rPEDV-D350A with a single mutation (D350A) in nsp14, which retained 29.0% of G-N-7 MTase activity, was viable. Recombinant rPEDV-D350A formed a significantly smaller plaque and had significant defects in viral protein synthesis and viral replication in Vero CCL-81 cells and intestinal porcine epithelial cells (IPEC-DQ). Notably, rPEDV-D350A induced significantly higher expression of both type I and III interferons in IPEC-DQ cells than the parental rPEDV. Collectively, our results demonstrate that G-N-7 MTase activity of PEDV modulates viral replication, gene expression, and innate immune responses.IMPORTANCE Coronaviruses (CoVs) include a wide range of important human and animal pathogens. Examples of human CoVs include severe acute respiratory syndrome coronavirus (SARS-CoV-1), Middle East respiratory syndrome coronavirus (MERS-CoV), and the most recently emerged SARS-CoV-2. Examples of pig CoVs include porcine epidemic diarrhea virus (PEDV), porcine deltacoronavirus (PDCoV), and swine enteric alphacoronavirus (SeACoV). There are no vaccines or antiviral drugs for most of these viruses. All known CoVs encode a bifunctional nsp14 protein which possesses ExoN and guanine-N-7 methyltransferase (G-N-7 MTase) activities, responsible for replication fidelity and RNA cap G-N-7 methylation, respectively. Here, we biochemically characterized G-N-7 MTase of PEDV nsp14 and found that G-N-7 MTase-deficient PEDV was defective in replication and induced greater responses of type I and III interferons. These findings highlight that CoV G-N-7 MTase may be a novel target for rational design of live attenuated vaccines and antiviral drugs.
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11
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Prospects of and Barriers to the Development of Epitope-Based Vaccines against Human Metapneumovirus. Pathogens 2020; 9:pathogens9060481. [PMID: 32570728 PMCID: PMC7350342 DOI: 10.3390/pathogens9060481] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 06/10/2020] [Accepted: 06/16/2020] [Indexed: 12/21/2022] Open
Abstract
Human metapneumovirus (HMPV) is a major cause of respiratory illnesses in children, the elderly and immunocompromised patients. Although this pathogen was only discovered in 2001, an enormous amount of research has been conducted in order to develop safe and effective vaccines to prevent people from contracting the disease. In this review, we summarize current knowledge about the most promising experimental B- and T-cell epitopes of human metapneumovirus for the rational design of HMPV vaccines using vector delivery systems, paying special attention to the conservation of these epitopes among different lineages/genotypes of HMPV. The prospects of the successful development of an epitope-based HMPV vaccine are discussed in the context of recent findings regarding HMPV’s ability to modulate host immunity. In particular, we discuss the lack of data on experimental human CD4 T-cell epitopes for HMPV despite the role of CD4 lymphocytes in both the induction of higher neutralizing antibody titers and the establishment of CD8 memory T-cell responses. We conclude that current research should be focused on searching for human CD4 T-cell epitopes of HMPV that can help us to design a safe and cross-protective epitope-based HMPV vaccine.
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12
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Lu M, Zhang Z, Xue M, Zhao BS, Harder O, Li A, Liang X, Gao TZ, Xu Y, Zhou J, Feng Z, Niewiesk S, Peeples ME, He C, Li J. N 6-methyladenosine modification enables viral RNA to escape recognition by RNA sensor RIG-I. Nat Microbiol 2020; 5:584-598. [PMID: 32015498 PMCID: PMC7137398 DOI: 10.1038/s41564-019-0653-9] [Citation(s) in RCA: 158] [Impact Index Per Article: 39.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 12/03/2019] [Indexed: 12/18/2022]
Abstract
Internal N6-methyladenosine (m6A) modification is one of the most common and abundant modifications of RNA. However, the biological roles of viral RNA m6A remain elusive. Here, using human metapneumovirus (HMPV) as a model, we demonstrate that m6A serves as a molecular marker for innate immune discrimination of self from non-self RNAs. We show that HMPV RNAs are m6A methylated and that viral m6A methylation promotes HMPV replication and gene expression. Inactivating m6A addition sites with synonymous mutations or demethylase resulted in m6A-deficient recombinant HMPVs and virion RNAs that induced increased expression of type I interferon, which was dependent on the cytoplasmic RNA sensor RIG-I, and not on melanoma differentiation-associated protein 5 (MDA5). Mechanistically, m6A-deficient virion RNA induces higher expression of RIG-I, binds more efficiently to RIG-I and facilitates the conformational change of RIG-I, leading to enhanced interferon expression. Furthermore, m6A-deficient recombinant HMPVs triggered increased interferon in vivo and were attenuated in cotton rats but retained high immunogenicity. Collectively, our results highlight that (1) viruses acquire m6A in their RNA as a means of mimicking cellular RNA to avoid detection by innate immunity and (2) viral RNA m6A can serve as a target to attenuate HMPV for vaccine purposes.
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Affiliation(s)
- Mijia Lu
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
| | - Zijie Zhang
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
| | - Miaoge Xue
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
| | - Boxuan Simen Zhao
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
| | - Olivia Harder
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
| | - Anzhong Li
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
| | - Xueya Liang
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
| | - Thomas Z Gao
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
| | - Yunsheng Xu
- The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Jiyong Zhou
- College of Animal Sciences, Zhejiang University, Hangzhou, China
| | - Zongdi Feng
- Center for Vaccines and Immunity, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Stefan Niewiesk
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
| | - Mark E Peeples
- Center for Vaccines and Immunity, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Chuan He
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, USA
- Howard Hughes Medical Institute, The University of Chicago, Chicago, IL, USA
| | - Jianrong Li
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA.
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13
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McMichael TM, Zhang Y, Kenney AD, Zhang L, Zani A, Lu M, Chemudupati M, Li J, Yount JS. IFITM3 Restricts Human Metapneumovirus Infection. J Infect Dis 2019; 218:1582-1591. [PMID: 29917090 DOI: 10.1093/infdis/jiy361] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 06/12/2018] [Indexed: 11/12/2022] Open
Abstract
Human metapneumovirus (hMPV) utilizes a bifurcated cellular entry strategy, fusing either with the plasma membrane or, after endocytosis, with the endosome membrane. Whether cellular factors restrict or enhance either entry pathway is largely unknown. We found that the interferon-induced transmembrane protein 3 (IFITM3) inhibits hMPV infection to an extent similar to endocytosis-inhibiting drugs, and an IFITM3 variant that accumulates at the plasma membrane in addition to its endosome localization provided increased virus restriction. Mechanistically, IFITM3 blocks hMPV F protein-mediated membrane fusion, and inhibition of infection was reversed by the membrane destabilizing drug amphotericin B. Conversely, we found that infection by some hMPV strains is enhanced by the endosomal protein toll-like receptor 7 (TLR7), and that IFITM3 retains the ability to restrict hMPV infection even in cells expressing TLR7. Overall, our results identify IFITM3 as an endosomal restriction factor that limits hMPV infection of cells.
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Affiliation(s)
- Temet M McMichael
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio.,Infectious Diseases Institute, The Ohio State University, Columbus, Ohio
| | - Yu Zhang
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio
| | - Adam D Kenney
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio.,Infectious Diseases Institute, The Ohio State University, Columbus, Ohio
| | - Lizhi Zhang
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio.,Infectious Diseases Institute, The Ohio State University, Columbus, Ohio
| | - Ashley Zani
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio.,Infectious Diseases Institute, The Ohio State University, Columbus, Ohio
| | - Mijia Lu
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio.,Infectious Diseases Institute, The Ohio State University, Columbus, Ohio
| | - Mahesh Chemudupati
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio.,Infectious Diseases Institute, The Ohio State University, Columbus, Ohio
| | - Jianrong Li
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio.,Infectious Diseases Institute, The Ohio State University, Columbus, Ohio
| | - Jacob S Yount
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio.,Infectious Diseases Institute, The Ohio State University, Columbus, Ohio
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14
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Hou Y, Ke H, Kim J, Yoo D, Su Y, Boley P, Chepngeno J, Vlasova AN, Saif LJ, Wang Q. Engineering a Live Attenuated Porcine Epidemic Diarrhea Virus Vaccine Candidate via Inactivation of the Viral 2'- O-Methyltransferase and the Endocytosis Signal of the Spike Protein. J Virol 2019; 93:e00406-19. [PMID: 31118255 PMCID: PMC6639265 DOI: 10.1128/jvi.00406-19] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 05/13/2019] [Indexed: 01/18/2023] Open
Abstract
Porcine epidemic diarrhea virus (PEDV) causes high mortality in neonatal piglets; however, effective and safe vaccines are still not available. We hypothesized that inactivation of the 2'-O-methyltransferase (2'-O-MTase) activity of nsp16 and the endocytosis signal of the spike protein attenuates PEDV yet retains its immunogenicity in pigs. We generated a recombinant PEDV, KDKE4A, with quadruple alanine substitutions in the catalytic tetrad of the 2'-O-MTase using a virulent infectious cDNA clone, icPC22A, as the backbone. Next, we constructed another mutant, KDKE4A-SYA, by abolishing the endocytosis signal of the spike protein of KDKE4A Compared with icPC22A, the KDKE4A and KDKE4A-SYA mutants replicated less efficiently in vitro but induced stronger type I and type III interferon responses. The pathogenesis and immunogenicities of the mutants were evaluated in gnotobiotic piglets. The virulence of KDKE4A-SYA and KDKE4A was significantly reduced compared with that of icPC22A. Mortality rates were 100%, 17%, and 0% in the icPC22A-, KDKE4A-, and KDKE4A-SYA-inoculated groups, respectively. At 21 days postinoculation (dpi), all surviving pigs were challenged orally with a high dose of icPC22A. The KDKE4A-SYA- and KDKE4A-inoculated pigs were protected from the challenge, because no KDKE4A-SYA- and one KDKE4A-inoculated pig developed diarrhea whereas all the pigs in the mock-inoculated group had severe diarrhea, and 33% of them died. Furthermore, we serially passaged the KDKE4A-SYA mutant in pigs three times and did not find any reversion of the introduced mutations. The data suggest that KDKE4A-SYA may be a PEDV vaccine candidate.IMPORTANCE PEDV is the most economically important porcine enteric viral pathogen and has caused immense economic losses in the pork industries in many countries. Effective and safe vaccines are desperately required but still not available. 2'-O-MTase (nsp16) is highly conserved among coronaviruses (CoVs), and the inactivation of nsp16 in live attenuated vaccines has been attempted for several betacoronaviruses. We show that inactivation of both 2'-O-MTase and the endocytosis signal of the spike protein is an approach to designing a promising live attenuated vaccine for PEDV. The in vivo passaging data also validated the stability of the KDKE4A-SYA mutant. KDKE4A-SYA warrants further evaluation in sows and their piglets and may be used as a platform for further optimization. Our findings further confirmed that nsp16 can be a universal target for CoV vaccine development and will aid in the development of vaccines against other emerging CoVs.
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Affiliation(s)
- Yixuan Hou
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, College of Food, Agriculture and Environmental Sciences, The Ohio State University, Wooster, Ohio, USA
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Wooster, Ohio, USA
| | - Hanzhong Ke
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Jineui Kim
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Dongwan Yoo
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Yunfang Su
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, College of Food, Agriculture and Environmental Sciences, The Ohio State University, Wooster, Ohio, USA
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Wooster, Ohio, USA
| | - Patricia Boley
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, College of Food, Agriculture and Environmental Sciences, The Ohio State University, Wooster, Ohio, USA
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Wooster, Ohio, USA
| | - Juliet Chepngeno
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, College of Food, Agriculture and Environmental Sciences, The Ohio State University, Wooster, Ohio, USA
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Wooster, Ohio, USA
| | - Anastasia N Vlasova
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, College of Food, Agriculture and Environmental Sciences, The Ohio State University, Wooster, Ohio, USA
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Wooster, Ohio, USA
| | - Linda J Saif
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, College of Food, Agriculture and Environmental Sciences, The Ohio State University, Wooster, Ohio, USA
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Wooster, Ohio, USA
| | - Qiuhong Wang
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, College of Food, Agriculture and Environmental Sciences, The Ohio State University, Wooster, Ohio, USA
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Wooster, Ohio, USA
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15
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Cross ST, Michalski D, Miller MR, Wilusz J. RNA regulatory processes in RNA virus biology. WILEY INTERDISCIPLINARY REVIEWS-RNA 2019; 10:e1536. [PMID: 31034160 PMCID: PMC6697219 DOI: 10.1002/wrna.1536] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 04/02/2019] [Indexed: 12/13/2022]
Abstract
Numerous post‐transcriptional RNA processes play a major role in regulating the quantity, quality and diversity of gene expression in the cell. These include RNA processing events such as capping, splicing, polyadenylation and modification, but also aspects such as RNA localization, decay, translation, and non‐coding RNA‐associated regulation. The interface between the transcripts of RNA viruses and the various RNA regulatory processes in the cell, therefore, has high potential to significantly impact virus gene expression, regulation, cytopathology and pathogenesis. Furthermore, understanding RNA biology from the perspective of an RNA virus can shed considerable light on the broad impact of these post‐transcriptional processes in cell biology. Thus the goal of this article is to provide an overview of the richness of cellular RNA biology and how RNA viruses use, usurp and/or avoid the associated machinery to impact the outcome of infection. This article is categorized under:RNA in Disease and Development > RNA in Disease
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Affiliation(s)
- Shaun T Cross
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado
| | - Daniel Michalski
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado
| | - Megan R Miller
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado
| | - Jeffrey Wilusz
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado
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16
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Establishment of an efficient reverse genetic system of Mumps virus S79 from cloned DNA. World J Pediatr 2019; 15:499-505. [PMID: 31456156 PMCID: PMC6785654 DOI: 10.1007/s12519-019-00286-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 07/01/2019] [Indexed: 01/01/2023]
Abstract
BACKGROUND Mumps is a common type of respiratory infectious disease caused by mumps virus (MuV), and can be effectively prevented by vaccination. In this study, a reverse genetic system of MuV that can facilitate the rational design of safer, more efficient mumps vaccine candidates is established. METHODS MuV-S79 cDNA clone was assembled into a full-length plasmid by means of the GeneArt™ High-Order Genetic Assembly System, and was rescued via reverse genetic technology. RT-PCR, sequencing, and immunofluorescence assays were used for rMuV-S79 authentication. Viral replication kinetics and in vivo experimental models were used to evaluate the replication, safety, and immunogenicity of rMuV-S79. RESULTS A full-length cDNA clone of MuV-S79 in the assembly process was generated by a novel plasmid assemble strategy, and a robust reverse genetic system of MuV-S79 was successfully established. The established rMuV-S79 strain could reach a high virus titer in vitro. The average viral titer of rMuV-S79 in the lung tissues was 2.68 ± 0.14 log10PFU/g lung tissue, and rMuV-S79 group did not induce inflammation in the lung tissues in cotton rats. Neutralizing antibody titers induced by rMuV-S79 were high, long-lasting and could provide complete protection against MuV wild strain challenge. CONCLUSION We have established a robust reverse genetic system of MuV-S79 which can facilitate the optimization of mumps vaccines. rMuV-S79 rescued could reach a high virus titer and the safety was proven in vivo. It could also provide complete protection against MuV wild strain challenge.
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17
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Kumar P, Srivastava M. Prophylactic and therapeutic approaches for human metapneumovirus. Virusdisease 2018; 29:434-444. [PMID: 30539045 PMCID: PMC6261883 DOI: 10.1007/s13337-018-0498-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 10/01/2018] [Indexed: 12/24/2022] Open
Abstract
Human metapneumovirus (HMPV) is an important pneumovirus which causes acute respiratory disease in human beings. The viral infection leads to mild to severe respiratory symptoms depending on the age and immune status of the infected individual. Several groups across the world are working on the development of immunogens and therapy to manage HMPV infection with promising results under laboratory conditions but till date any virus specific vaccine or therapy has not been approved for clinical use. This minireview gives an overview of the prophylactic and therapeutic approaches to manage HMPV infections.
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Affiliation(s)
- Prashant Kumar
- Amity Institute of Virology and Immunology, Amity University Uttar Pradesh, Sector-125, Noida, U.P. 201301 India
| | - Mansi Srivastava
- Amity Institute of Virology and Immunology, Amity University Uttar Pradesh, Sector-125, Noida, U.P. 201301 India
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18
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Wang Y, Liu R, Lu M, Yang Y, Zhou D, Hao X, Zhou D, Wang B, Li J, Huang YW, Zhao Z. Enhancement of safety and immunogenicity of the Chinese Hu191 measles virus vaccine by alteration of the S-adenosylmethionine (SAM) binding site in the large polymerase protein. Virology 2018. [PMID: 29525671 PMCID: PMC6413878 DOI: 10.1016/j.virol.2018.02.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The live-attenuated measles virus (MV) vaccine based on the Hu191 strain has played a significant role in controlling measles in China. However, it has considerable adverse effects that may cause public health burden. We hypothesize that the safety and efficacy of MV vaccine can be improved by altering the S-adenosylmethionine (SAM) binding site in the conserved region VI of the large polymerase protein. To test this hypothesis, we established an efficient reverse genetics system for the rMV-Hu191 strain and generated two recombinant MV-Hu191 carrying mutations in the SAM binding site. These two mutants grew to high titer in Vero cells, were genetically stable, and were significantly more attenuated in vitro and in vivo compared to the parental rMV-Hu191 vaccine strain. Importantly, both MV-Hu191 mutants triggered a higher neutralizing antibody than rMV-Hu191 vaccine and provided complete protection against MV challenge. These results demonstrate its potential for an improved MV vaccine candidate. An efficient reverse genetics system for Chinese MV-Hu191 strain was developed. rMV-Hu191 mutants in SAM binding site are attenuated in vitro and in vivo. rMV-Hu191 mutants in SAM binding site enhance the safety and immunogenicity of MV vaccine.
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Affiliation(s)
- Yilong Wang
- Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Rongxian Liu
- Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Mijia Lu
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
| | - Yingzhi Yang
- Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Duo Zhou
- Children's Hospital, Zhejiang University School of Medicine, Hangzhou 310052, Zhejiang, China
| | - Xiaoqiang Hao
- Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Dongming Zhou
- Children's Hospital, Zhejiang University School of Medicine, Hangzhou 310052, Zhejiang, China
| | - Bin Wang
- Institute of Preventive Veterinary Medicine and Key Laboratory of Animal Virology of Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Jianrong Li
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA.
| | - Yao-Wei Huang
- Institute of Preventive Veterinary Medicine and Key Laboratory of Animal Virology of Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.
| | - Zhengyan Zhao
- Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Children's Hospital, Zhejiang University School of Medicine, Hangzhou 310052, Zhejiang, China.
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19
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Ji Y, Liu T, Du Y, Cui X, Yu Q, Wang Z, Zhang J, Li Y, Zhu Q. A novel genotype VII Newcastle disease virus vaccine candidate generated by mutation in the L and F genes confers improved protection in chickens. Vet Microbiol 2018. [PMID: 29519533 DOI: 10.1016/j.vetmic.2018.01.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Administration of vaccines combined with the good management and strict biosecurity is an effective way for Newcastle disease (ND) control. However, vaccine failure is continuously reported in some countries mainly because the antigenic difference between the used vaccine and field strains even they are of one serotype. Therefore, development of antigen-matched ND vaccines is needed to improve the vaccine efficacy in birds. In this study, we introduced four site mutations, K1756A, D1881A, K1917A and E1954Q, respectively, into the large protein gene of the virulent genotype VII Newcastle disease virus (NDV) G7 strain using reverse genetics technology. Four rescued NDVs were sharply attenuated for the pathogenicity in chickens. One of these mutants, E1954Q, was further manipulated by replacing the F cleavage site sequence of typical velogenic strains with that of the LaSota vaccine, resulting in a new mutant, G7M. Biological characterization showed that G7M was safe and genetically stable after serial passages in embryos and chickens. Vaccination of chickens with G7M induced a progressive elevation of the homologous antibodies and markedly higher CD8+ T cell percentage, T cell proliferation and IFN-γ than LaSota. G7M conferred full protection against genotype VII NDV challenge, and more importantly, it effectively reduced the challenge virus replication and shedding in chickens. Together, our data suggest that G7M is a promising genotype VII vaccine candidate, and the novel attenuation approach designed in this study could be used to develop new antigen-matched NDV vaccines.
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Affiliation(s)
- Yanhong Ji
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, PR China
| | - Tao Liu
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, PR China; College of Animal Sciences and Technologies, Anhui Agricultural University, Hefei, 230036, PR China
| | - Yingying Du
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, PR China
| | - Xiaole Cui
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, PR China
| | - Qingzhong Yu
- United States Department of Agriculture, Agriculture Research Service, US National Poultry Research Center, Southeast Poultry Research Laboratory, Athens, GA 30605, USA
| | - Zhengxiang Wang
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, PR China
| | - Jinjin Zhang
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, PR China
| | - Yu Li
- College of Animal Sciences and Technologies, Anhui Agricultural University, Hefei, 230036, PR China.
| | - Qiyun Zhu
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, PR China.
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20
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Abstract
Human metapneumovirus (HMPV) is a leading cause of acute respiratory infection, particularly in children, immunocompromised patients, and the elderly. HMPV, which is closely related to avian metapneumovirus subtype C, has circulated for at least 65 years, and nearly every child will be infected with HMPV by the age of 5. However, immunity is incomplete, and re-infections occur throughout adult life. Symptoms are similar to those of other respiratory viral infections, ranging from mild (cough, rhinorrhea, and fever) to more severe (bronchiolitis and pneumonia). The preferred method for diagnosis is reverse transcription-polymerase chain reaction as HMPV is difficult to culture. Although there have been many advances made in the past 16 years since its discovery, there are still no US Food and Drug Administration-approved antivirals or vaccines available to treat HMPV. Both small animal and non-human primate models have been established for the study of HMPV. This review will focus on the epidemiology, transmission, and clinical manifestations in humans as well as the animal models of HMPV pathogenesis and host immune response.
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Affiliation(s)
- Nazly Shafagati
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - John Williams
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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21
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Aouadi W, Eydoux C, Coutard B, Martin B, Debart F, Vasseur JJ, Contreras JM, Morice C, Quérat G, Jung ML, Canard B, Guillemot JC, Decroly E. Toward the identification of viral cap-methyltransferase inhibitors by fluorescence screening assay. Antiviral Res 2017; 144:330-339. [PMID: 28676301 PMCID: PMC7113892 DOI: 10.1016/j.antiviral.2017.06.021] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 06/28/2017] [Accepted: 06/29/2017] [Indexed: 11/26/2022]
Abstract
Two highly pathogenic human coronaviruses associated with severe respiratory syndromes emerged since the beginning of the century. The severe acute respiratory syndrome SARS-coronavirus (CoV) spread first in southern China in 2003 with about 8000 infected cases in few months. Then in 2012, the Middle East respiratory syndrome (MERS-CoV) emerged from the Arabian Peninsula giving a still on-going epidemic associated to a high fatality rate. CoVs are thus considered a major health threat. This is especially true as no vaccine nor specific therapeutic are available against either SARS- or MERS-CoV. Therefore, new drugs need to be identified in order to develop antiviral treatments limiting CoV replication. In this study, we focus on the nsp14 protein, which plays a key role in virus replication as it methylates the RNA cap structure at the N7 position of the guanine. We developed a high-throughput N7-MTase assay based on Homogenous Time Resolved Fluorescence (HTRF®) and screened chemical libraries (2000 compounds) on the SARS-CoV nsp14. 20 compounds inhibiting the SARS-CoV nsp14 were further evaluated by IC50 determination and their specificity was assessed toward flavivirus- and human cap N7-MTases. Our results reveal three classes of compounds: 1) molecules inhibiting several MTases as well as the dengue virus polymerase activity unspecifically, 2) pan MTases inhibitors targeting both viral and cellular MTases, and 3) inhibitors targeting one viral MTase more specifically showing however activity against the human cap N7-MTase. These compounds provide a first basis towards the development of more specific inhibitors of viral methyltransferases.
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Affiliation(s)
- Wahiba Aouadi
- Aix Marseille Université, CNRS, AFMB UMR 7257, Marseille, France
| | - Cécilia Eydoux
- Aix Marseille Université, CNRS, AFMB UMR 7257, Marseille, France
| | - Bruno Coutard
- Aix Marseille Université, CNRS, AFMB UMR 7257, Marseille, France
| | - Baptiste Martin
- Aix Marseille Université, CNRS, AFMB UMR 7257, Marseille, France
| | - Françoise Debart
- IBMM, CNRS, Université Montpellier, ENSCM, Campus Triolet, Place E. Bataillon, 34095, Montpellier Cedex 05, France
| | - Jean Jacques Vasseur
- IBMM, CNRS, Université Montpellier, ENSCM, Campus Triolet, Place E. Bataillon, 34095, Montpellier Cedex 05, France
| | | | | | - Gilles Quérat
- UMR "Emergence des Pathologies Virales" (EPV: Aix-Marseille Université - IRD 190 - Inserm 1207 - EHESP), Marseille, France
| | | | - Bruno Canard
- Aix Marseille Université, CNRS, AFMB UMR 7257, Marseille, France
| | | | - Etienne Decroly
- Aix Marseille Université, CNRS, AFMB UMR 7257, Marseille, France.
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22
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Abstract
Globally, as a leading agent of acute respiratory tract infections in children <5 years of age and the elderly, the human metapneumovirus (HMPV) has gained considerable attention. As inferred from studies comparing vaccinated and experimentally infected mice, the acquired immune response elicited by this pathogen fails to efficiently clear the virus from the airways, which leads to an exaggerated inflammatory response and lung damage. Furthermore, after disease resolution, there is a poor development of T and B cell immunological memory, which is believed to promote reinfections and viral spread in the community. In this article, we discuss the molecular mechanisms that shape the interactions of HMPV with host tissues that lead to pulmonary pathology and to the development of adaptive immunity that fails to protect against natural infections by this virus.
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23
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A Reverse Genetics Approach for the Design of Methyltransferase-Defective Live Attenuated Avian Metapneumovirus Vaccines. Methods Mol Biol 2016. [PMID: 27076293 DOI: 10.1007/978-1-4939-3389-1_7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
Avian metapneumovirus (aMPV), also known as avian pneumovirus or turkey rhinotracheitis virus, is the causative agent of turkey rhinotracheitis and is associated with swollen head syndrome in chickens. aMPV belongs to the family Paramyxoviridae which includes many important human pathogens such as human respiratory syncytial virus (RSV), human metapneumovirus (hMPV), and human parainfluenza virus type 3 (PIV3). The family also includes highly lethal emerging pathogens such as Nipah virus and Hendra virus, as well as agriculturally important viruses such as Newcastle disease virus (NDV). For many of these viruses, there is no effective vaccine. Here, we describe a reverse genetics approach to develop live attenuated aMPV vaccines by inhibiting the viral mRNA cap methyltransferase. The viral mRNA cap methyltransferase is an excellent target for the attenuation of paramyxoviruses because it plays essential roles in mRNA stability, efficient viral protein translation and innate immunity. We have described in detail the materials and methods used to generate recombinant aMPVs that lack viral mRNA cap methyltransferase activity. We have also provided methods to evaluate the genetic stability, pathogenesis, and immunogenicity of live aMPV vaccine candidates in turkeys.
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24
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Young DF, Andrejeva J, Li X, Inesta-Vaquera F, Dong C, Cowling VH, Goodbourn S, Randall RE. Human IFIT1 Inhibits mRNA Translation of Rubulaviruses but Not Other Members of the Paramyxoviridae Family. J Virol 2016; 90:9446-56. [PMID: 27512068 PMCID: PMC5044818 DOI: 10.1128/jvi.01056-16] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 08/03/2016] [Indexed: 12/24/2022] Open
Abstract
UNLABELLED We have previously shown that IFIT1 is primarily responsible for the antiviral action of interferon (IFN) alpha/beta against parainfluenza virus type 5 (PIV5), selectively inhibiting the translation of PIV5 mRNAs. Here we report that while PIV2, PIV5, and mumps virus (MuV) are sensitive to IFIT1, nonrubulavirus members of the paramyxoviridae such as PIV3, Sendai virus (SeV), and canine distemper virus (CDV) are resistant. The IFIT1 sensitivity of PIV5 was not rescued by coinfection with an IFIT1-resistant virus (PIV3), demonstrating that PIV3 does not specifically inhibit the antiviral activity of IFIT1 and that the inhibition of PIV5 mRNAs is regulated by cis-acting elements. We developed an in vitro translation system using purified human IFIT1 to further investigate the mechanism of action of IFIT1. While the translations of PIV2, PIV5, and MuV mRNAs were directly inhibited by IFIT1, the translations of PIV3, SeV, and CDV mRNAs were not. Using purified human mRNA-capping enzymes, we show biochemically that efficient inhibition by IFIT1 is dependent upon a 5' guanosine nucleoside cap (which need not be N7 methylated) and that this sensitivity is partly abrogated by 2'O methylation of the cap 1 ribose. Intriguingly, PIV5 M mRNA, in contrast to NP mRNA, remained sensitive to inhibition by IFIT1 following in vitro 2'O methylation, suggesting that other structural features of mRNAs may influence their sensitivity to IFIT1. Thus, surprisingly, the viral polymerases (which have 2'-O-methyltransferase activity) of rubulaviruses do not protect these viruses from inhibition by IFIT1. Possible biological consequences of this are discussed. IMPORTANCE Paramyxoviruses cause a wide variety of diseases, and yet most of their genes encode structural proteins and proteins involved in their replication cycle. Thus, the amount of genetic information that determines the type of disease that paramyxoviruses cause is relatively small. One factor that will influence disease outcomes is how they interact with innate host cell defenses, including the interferon (IFN) system. Here we show that different paramyxoviruses interact in distinct ways with cells in a preexisting IFN-induced antiviral state. Strikingly, all the rubulaviruses tested were sensitive to the antiviral action of ISG56/IFIT1, while all the other paramyxoviruses tested were resistant. We developed novel in vitro biochemical assays to investigate the mechanism of action of IFIT1, demonstrating that the mRNAs of rubulaviruses can be directly inhibited by IFIT1 and that this is at least partially because their mRNAs are not correctly methylated.
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Affiliation(s)
- D F Young
- School of Biology, Centre for Biomolecular Sciences, University of St. Andrews, St. Andrews, Fife, United Kingdom
| | - J Andrejeva
- School of Biology, Centre for Biomolecular Sciences, University of St. Andrews, St. Andrews, Fife, United Kingdom
| | - X Li
- Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - F Inesta-Vaquera
- School of Life Sciences, Centre for Gene Regulation and Expression, University of Dundee, Dundee, United Kingdom
| | - C Dong
- Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - V H Cowling
- School of Life Sciences, Centre for Gene Regulation and Expression, University of Dundee, Dundee, United Kingdom
| | - S Goodbourn
- Institute for Infection and Immunity, St. George's, University of London, London, United Kingdom
| | - R E Randall
- School of Biology, Centre for Biomolecular Sciences, University of St. Andrews, St. Andrews, Fife, United Kingdom
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25
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Phosphorylation of Human Metapneumovirus M2-1 Protein Upregulates Viral Replication and Pathogenesis. J Virol 2016; 90:7323-7338. [PMID: 27252537 DOI: 10.1128/jvi.00755-16] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 05/25/2016] [Indexed: 01/02/2023] Open
Abstract
UNLABELLED Human metapneumovirus (hMPV) is a major causative agent of upper- and lower-respiratory-tract infections in infants, the elderly, and immunocompromised individuals worldwide. Like all pneumoviruses, hMPV encodes the zinc binding protein M2-1, which plays important regulatory roles in RNA synthesis. The M2-1 protein is phosphorylated, but the specific role(s) of the phosphorylation in viral replication and pathogenesis remains unknown. In this study, we found that hMPV M2-1 is phosphorylated at amino acid residues S57 and S60. Subsequent mutagenesis found that phosphorylation is not essential for zinc binding activity and oligomerization, whereas inhibition of zinc binding activity abolished the phosphorylation and oligomerization of the M2-1 protein. Using a reverse genetics system, recombinant hMPVs (rhMPVs) lacking either one or both phosphorylation sites in the M2-1 protein were recovered. These recombinant viruses had a significant decrease in both genomic RNA replication and mRNA transcription. In addition, these recombinant viruses were highly attenuated in cell culture and cotton rats. Importantly, rhMPVs lacking phosphorylation in the M2-1 protein triggered high levels of neutralizing antibody and provided complete protection against challenge with wild-type hMPV. Collectively, these data demonstrated that phosphorylation of the M2-1 protein upregulates hMPV RNA synthesis, replication, and pathogenesis in vivo IMPORTANCE The pneumoviruses include many important human and animal pathogens, such as human respiratory syncytial virus (hRSV), hMPV, bovine RSV, and avian metapneumovirus (aMPV). Among these viruses, hRSV and hMPV are the leading causes of acute respiratory tract infection in infants and children. Currently, there is no antiviral or vaccine to combat these diseases. All known pneumoviruses encode a zinc binding protein, M2-1, which is a transcriptional antitermination factor. In this work, we found that phosphorylation of M2-1 is essential for virus replication and pathogenesis in vivo Recombinant hMPVs lacking phosphorylation in M2-1 exhibited limited replication in the upper and lower respiratory tract and triggered strong protective immunity in cotton rats. This work highlights the important role of M2-1 phosphorylation in viral replication and that inhibition of M2-1 phosphorylation may serve as a novel approach to develop live attenuated vaccines as well as antiviral drugs for pneumoviruses.
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26
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New Approaches for Immunization and Therapy against Human Metapneumovirus. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2015; 22:858-66. [PMID: 26063237 DOI: 10.1128/cvi.00230-15] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Human metapneumovirus (HMPV) is a paramyxovirus discovered in 2001 in the Netherlands. Studies have identified HMPV as an important causative agent of acute respiratory disease in infants, the elderly, and immunocompromised individuals. Clinical signs of infection range from mild upper respiratory illness to more serious lower respiratory illness, including bronchiolitis and pneumonia. There are currently no licensed therapeutics or vaccines against HMPV. However, several research groups have tested vaccine candidates and monoclonal antibodies in various animal models. Several of these approaches have shown promise in animal models. This minireview summarizes the current therapies used to treat HMPV infection as well as different approaches for immunization.
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27
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Zinc binding activity of human metapneumovirus M2-1 protein is indispensable for viral replication and pathogenesis in vivo. J Virol 2015; 89:6391-405. [PMID: 25855728 DOI: 10.1128/jvi.03488-14] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 03/30/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Human metapneumovirus (hMPV) is a member of the Pneumovirinae subfamily in the Paramyxoviridae family that causes respiratory tract infections in humans. Unlike members of the Paramyxovirinae subfamily, the polymerase complex of pneumoviruses requires an additional cofactor, the M2-1 protein, which functions as a transcriptional antitermination factor. The M2-1 protein was found to incorporate zinc ions, although the specific role(s) of the zinc binding activity in viral replication and pathogenesis remains unknown. In this study, we found that the third cysteine (C21) and the last histidine (H25) in the zinc binding motif (CCCH) of hMPV M2-1 were essential for zinc binding activity, whereas the first two cysteines (C7 and C15) play only minor or redundant roles in zinc binding. In addition, the zinc binding motif is essential for the oligomerization of M2-1. Subsequently, recombinant hMPVs (rhMPVs) carrying mutations in the zinc binding motif were recovered. Interestingly, rhMPV-C21S and -H25L mutants, which lacked zinc binding activity, had delayed replication in cell culture and were highly attenuated in cotton rats. In contrast, rhMPV-C7S and -C15S strains, which retained 60% of the zinc binding activity, replicated as efficiently as rhMPV in cotton rats. Importantly, rhMPVs that lacked zinc binding activity triggered high levels of neutralizing antibody and provided complete protection against challenge with rhMPV. Taken together, these results demonstrate that zinc binding activity is indispensable for viral replication and pathogenesis in vivo. These results also suggest that inhibition of zinc binding activity may serve as a novel approach to rationally attenuate hMPV and perhaps other pneumoviruses for vaccine purposes. IMPORTANCE The pneumoviruses include many important human and animal pathogens, such as human respiratory syncytial virus (hRSV), hMPV, bovine RSV, and avian metapneumovirus (aMPV). Among these viruses, hRSV and hMPV are the leading causes of acute respiratory tract infection in infants and children. Despite major efforts, there is no antiviral or vaccine to combat these diseases. All known pneumoviruses encode a zinc binding protein, M2-1, which is a transcriptional antitermination factor. In this work, we found that the zinc binding activity of M2-1 is essential for virus replication and pathogenesis in vivo. Recombinant hMPVs that lacked zinc binding activity were not only defective in replication in the upper and lower respiratory tract but also triggered a strong protective immunity in cotton rats. Thus, inhibition of M2-1 zinc binding activity can lead to the development of novel, live attenuated vaccines, as well as antiviral drugs for pneumoviruses.
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28
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Hyde JL, Diamond MS. Innate immune restriction and antagonism of viral RNA lacking 2׳-O methylation. Virology 2015; 479-480:66-74. [PMID: 25682435 PMCID: PMC4424151 DOI: 10.1016/j.virol.2015.01.019] [Citation(s) in RCA: 130] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 01/22/2015] [Indexed: 01/31/2023]
Abstract
N-7 and 2′-O methylation of host cell mRNA occurs in the nucleus and results in the generation of cap structures (cap 0, m7GpppN; cap 1, m7GpppNm) that control gene expression by modulating nuclear export, splicing, turnover, and protein synthesis. Remarkably, RNA cap modification also contributes to mammalian cell host defense as viral RNA lacking 2′-O methylation is sensed and inhibited by IFIT1, an interferon (IFN) stimulated gene (ISG). Accordingly, pathogenic viruses that replicate in the cytoplasm have evolved mechanisms to circumvent IFIT1 restriction and facilitate infection of mammalian cells. These include: (a) generating cap 1 structures on their RNA through cap-snatching or virally-encoded 2′-O methyltransferases, (b) using cap-independent means of translation, or (c) using RNA secondary structural motifs to antagonize IFIT1 binding. This review will discuss new insights as to how specific modifications at the 5′-end of viral RNA modulate host pathogen recognition responses to promote infection and disease.
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Affiliation(s)
- Jennifer L Hyde
- Departments of Medicine, Washington University School of Medicine, St Louis., MO 63110, USA
| | - Michael S Diamond
- Departments of Medicine, Washington University School of Medicine, St Louis., MO 63110, USA; Molecular Microbiology, Washington University School of Medicine, St Louis., MO 63110 USA; Pathology & Immunology, Washington University School of Medicine, St Louis., MO 63110, USA; The Center for Human Immunology and Immunotherapy Programs, Washington University School of Medicine, St Louis., MO 63110, USA.
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29
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Menachery VD, Debbink K, Baric RS. Coronavirus non-structural protein 16: evasion, attenuation, and possible treatments. Virus Res 2014; 194:191-9. [PMID: 25278144 PMCID: PMC4260984 DOI: 10.1016/j.virusres.2014.09.009] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Revised: 09/18/2014] [Accepted: 09/19/2014] [Indexed: 12/15/2022]
Abstract
Identifies components required for CoV 2′O-MTase activity including structural motifs and interaction partners. Demonstrates attenuation of NSP16 mutants in multiple CoV strains. Defines innate immune components including MDA5 and IFIT proteins that mediate the attenuation of 2′O-MTase CoV mutants. Provides approaches to exploit 2′O-MTase pathways for antiviral treatment of CoVs and other viruses.
The recent emergence of Middle East Respiratory Syndrome Coronavirus (MERS-CoV), nearly a decade after the Severe Acute Respiratory Syndrome (SARS) CoV, highlights the importance of understanding and developing therapeutic treatment for current and emergent CoVs. This manuscript explores the role of NSP16, a 2′O-methyl-transferase (2′O-MTase), in CoV infection and the host immune response. The review highlights conserved motifs, required interaction partners, as well as the attenuation of NSP16 mutants, and restoration of these mutants in specific immune knockouts. Importantly, the work also identifies a number of approaches to exploit this understanding for therapeutic treatment and the data clearly illustrate the importance of NSP16 2′O-MTase activity for CoV infection and pathogenesis.
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Affiliation(s)
- Vineet D Menachery
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC 27599, USA.
| | - Kari Debbink
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC 27599, USA; Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Ralph S Baric
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC 27599, USA; Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC 27599, USA
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