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A Novel Nanobody Targeting Middle East Respiratory Syndrome Coronavirus (MERS-CoV) Receptor-Binding Domain Has Potent Cross-Neutralizing Activity and Protective Efficacy against MERS-CoV. J Virol 2018; 92:JVI.00837-18. [PMID: 29950421 PMCID: PMC6146697 DOI: 10.1128/jvi.00837-18] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 06/25/2018] [Indexed: 12/22/2022] Open
Abstract
Therapeutic development is critical for preventing and treating continual MERS-CoV infections in humans and camels. Because of their small size, nanobodies (Nbs) have advantages as antiviral therapeutics (e.g., high expression yield and robustness for storage and transportation) and also potential limitations (e.g., low antigen-binding affinity and fast renal clearance). Here, we have developed novel Nbs that specifically target the receptor-binding domain (RBD) of MERS-CoV spike protein. They bind to a conserved site on MERS-CoV RBD with high affinity, blocking RBD's binding to MERS-CoV receptor. Through engineering a C-terminal human Fc tag, the in vivo half-life of the Nbs is significantly extended. Moreover, the Nbs can potently cross-neutralize the infections of diverse MERS-CoV strains isolated from humans and camels. The Fc-tagged Nb also completely protects humanized mice from lethal MERS-CoV challenge. Taken together, our study has discovered novel Nbs that hold promise as potent, cost-effective, and broad-spectrum anti-MERS-CoV therapeutic agents. The newly emerged Middle East respiratory syndrome coronavirus (MERS-CoV) continues to infect humans and camels, calling for efficient, cost-effective, and broad-spectrum strategies to control its spread. Nanobodies (Nbs) are single-domain antibodies derived from camelids and sharks and are potentially cost-effective antivirals with small size and great expression yield. In this study, we developed a novel neutralizing Nb (NbMS10) and its human-Fc-fused version (NbMS10-Fc), both of which target the MERS-CoV spike protein receptor-binding domain (RBD). We further tested their receptor-binding affinity, recognizing epitopes, cross-neutralizing activity, half-life, and efficacy against MERS-CoV infection. Both Nbs can be expressed in yeasts with high yield, bind to MERS-CoV RBD with high affinity, and block the binding of MERS-CoV RBD to the MERS-CoV receptor. The binding site of the Nbs on the RBD was mapped to be around residue Asp539, which is part of a conserved conformational epitope at the receptor-binding interface. NbMS10 and NbMS10-Fc maintained strong cross-neutralizing activity against divergent MERS-CoV strains isolated from humans and camels. Particularly, NbMS10-Fc had significantly extended half-life in vivo; a single-dose treatment of NbMS10-Fc exhibited high prophylactic and therapeutic efficacy by completely protecting humanized mice from lethal MERS-CoV challenge. Overall, this study proves the feasibility of producing cost-effective, potent, and broad-spectrum Nbs against MERS-CoV and has produced Nbs with great potentials as anti-MERS-CoV therapeutics. IMPORTANCE Therapeutic development is critical for preventing and treating continual MERS-CoV infections in humans and camels. Because of their small size, nanobodies (Nbs) have advantages as antiviral therapeutics (e.g., high expression yield and robustness for storage and transportation) and also potential limitations (e.g., low antigen-binding affinity and fast renal clearance). Here, we have developed novel Nbs that specifically target the receptor-binding domain (RBD) of MERS-CoV spike protein. They bind to a conserved site on MERS-CoV RBD with high affinity, blocking RBD's binding to MERS-CoV receptor. Through engineering a C-terminal human Fc tag, the in vivo half-life of the Nbs is significantly extended. Moreover, the Nbs can potently cross-neutralize the infections of diverse MERS-CoV strains isolated from humans and camels. The Fc-tagged Nb also completely protects humanized mice from lethal MERS-CoV challenge. Taken together, our study has discovered novel Nbs that hold promise as potent, cost-effective, and broad-spectrum anti-MERS-CoV therapeutic agents.
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202
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Fan C, Wu X, Liu Q, Li Q, Liu S, Lu J, Yang Y, Cao Y, Huang W, Liang C, Ying T, Jiang S, Wang Y. A Human DPP4-Knockin Mouse's Susceptibility to Infection by Authentic and Pseudotyped MERS-CoV. Viruses 2018; 10:v10090448. [PMID: 30142928 PMCID: PMC6164841 DOI: 10.3390/v10090448] [Citation(s) in RCA: 38] [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: 06/24/2018] [Revised: 08/13/2018] [Accepted: 08/17/2018] [Indexed: 01/01/2023] Open
Abstract
Infection by the Middle East respiratory syndrome coronavirus (MERS-CoV) causes respiratory illness and has a high mortality rate (~35%). The requirement for the virus to be manipulated in a biosafety level three (BSL-3) facility has impeded development of urgently-needed antiviral agents. Here, we established anovel mouse model by inserting human dipeptidyl peptidase 4 (hDPP4) into the Rosa26 locus using CRISPR/Cas9, resulting in global expression of the transgene in a genetically stable mouse line. The mice were highly susceptible to infection by MERS-CoV clinical strain hCoV-EMC, which induced severe diffuse pulmonary disease in the animals, and could also be infected by an optimized pseudotyped MERS-CoV. Administration of the neutralizing monoclonal antibodies, H111-1 and m336, as well as a fusion inhibitor peptide, HR2P-M2, protected mice from challenge with authentic and pseudotyped MERS-CoV. These results confirmed that the hDPP4-knockin mouse is a novel model for studies of MERS-CoV pathogenesis and anti-MERS-CoV antiviral agents in BSL-3 and BSL-2facilities, respectively.
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Affiliation(s)
- Changfa Fan
- Division of Animal Model Research, Institute for Laboratory Animal Resources, National Institutes for Food and Drug Control, Beijing 100050, China.
| | - Xi Wu
- Division of Animal Model Research, Institute for Laboratory Animal Resources, National Institutes for Food and Drug Control, Beijing 100050, China.
| | - Qiang Liu
- Division of HIV/AIDS and Sex-Transmitted Virus Vaccines, National Institutes for Food and Drug Control, Beijing 100050, China.
| | - Qianqian Li
- Division of HIV/AIDS and Sex-Transmitted Virus Vaccines, National Institutes for Food and Drug Control, Beijing 100050, China.
| | - Susu Liu
- Division of Animal Model Research, Institute for Laboratory Animal Resources, National Institutes for Food and Drug Control, Beijing 100050, China.
| | - Jianjun Lu
- National Center for Safety Evaluation of Drugs, Institute for Food and Drug Safety Evaluation, National Institutes for Food and Drug Control, A8 Hongda Middle Street, Beijing Economic-Technological Development Area, Beijing 100176, China.
| | - Yanwei Yang
- National Center for Safety Evaluation of Drugs, Institute for Food and Drug Safety Evaluation, National Institutes for Food and Drug Control, A8 Hongda Middle Street, Beijing Economic-Technological Development Area, Beijing 100176, China.
| | - Yuan Cao
- Division of Animal Model Research, Institute for Laboratory Animal Resources, National Institutes for Food and Drug Control, Beijing 100050, China.
| | - Weijin Huang
- Division of HIV/AIDS and Sex-Transmitted Virus Vaccines, National Institutes for Food and Drug Control, Beijing 100050, China.
| | - Chunnan Liang
- Division of Animal Model Research, Institute for Laboratory Animal Resources, National Institutes for Food and Drug Control, Beijing 100050, China.
| | - Tianlei Ying
- Key Laboratory of Medical Molecular Virology of the Ministries of Education and Health, Shanghai Medical College, Fudan University, Shanghai 200032, China.
| | - Shibo Jiang
- Key Laboratory of Medical Molecular Virology of the Ministries of Education and Health, Shanghai Medical College, Fudan University, Shanghai 200032, China.
| | - Youchun Wang
- Division of HIV/AIDS and Sex-Transmitted Virus Vaccines, National Institutes for Food and Drug Control, Beijing 100050, China.
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Abstract
INTRODUCTION Six years have passed since Middle East respiratory syndrome (MERS) coronavirus (MERS-CoV), a newly emerging infectious virus, was first reported in 2012. Although MERS-CoV has had a consistently high mortality rate in humans, no vaccines have been approved to prevent MERS-CoV infection in humans. MERS-CoV spike (S) protein is a key target for development of MERS vaccines. AREAS COVERED In this review, we illustrate the structure and function of S protein as a vaccine target, describe available animal models for evaluating MERS vaccines, and summarize recent progress on MERS-CoV S-based vaccines, focusing on their ability to elicit antibody and/or cellular immune responses, neutralizing antibodies, and protection against MERS-CoV infection in different models. Prospects for future MERS-CoV S-based vaccines are discussed. EXPERT COMMENTARY The majority of MERS vaccines under development are based on MERS-CoV S protein, including full-length S, S1, and receptor-binding domain (RBD). While it is essential to evaluate the safety of full-length S and S1-based MERS vaccines, further improvement of the efficacy of RBD-based vaccines using novel strategies would be necessary. Overall, this review provides informative guidance for designing and developing safe and effective MERS vaccines based on viral S protein.
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Affiliation(s)
- Yusen Zhou
- a State Key Laboratory of Pathogen and Biosecurity , Beijing Institute of Microbiology and Epidemiology , Beijing , China
| | - Shibo Jiang
- b Lindsley F. Kimball Research Institute, New York Blood Center , New York , NY , USA.,c Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Shanghai Medical College and Institute of Medical Microbiology , Fudan University , Shanghai , China
| | - Lanying Du
- b Lindsley F. Kimball Research Institute, New York Blood Center , New York , NY , USA
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204
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Production of a Monoclonal Antibody Targeting the M Protein of MERS-CoV for Detection of MERS-CoV Using a Synthetic Peptide Epitope Formulated with a CpG-DNA-Liposome Complex. Int J Pept Res Ther 2018; 25:819-826. [PMID: 32214929 PMCID: PMC7087630 DOI: 10.1007/s10989-018-9731-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/27/2018] [Indexed: 01/08/2023]
Abstract
The Middle East respiratory syndrome-related coronavirus (MERS-CoV) contains four major structural proteins, the spike glycoprotein, nucleocapsid phosphoprotein, membrane (M) glycoprotein and small envelope glycoprotein. The M protein of MERS-CoV has a role in the morphogenesis or assembly of the virus and inhibits type I interferon expression in infected cells. Here, we produced a monoclonal antibody specific against the M protein of MERS-CoV by injecting BALB/c mice with a complex containing the epitope peptide and CpG–DNA encapsulated with a phosphatidyl-β-oleoyl-γ-palmitoyl ethanolamine (DOPE):cholesterol hemisuccinate (CHEMS). The monoclonal antibody was reactive to the epitope peptide of the M protein of MERS-CoV which was confirmed by western blotting and immunoprecipitations. Indirect immunofluorescence assay and confocal image analysis showed that the monoclonal antibody binds specifically to the M protein of MERS-CoV in the virus-infected cells. Further studies using this monoclonal antibody may provide important information on the function of the M protein and its future application in diagnostics.
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205
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Combining New Non-Nucleoside Reverse Transcriptase Inhibitors (RTIs) with AZT Results in Strong Synergism against Multi-RTI-Resistant HIV-1 Strains. Molecules 2018; 23:molecules23071599. [PMID: 30004408 PMCID: PMC6099689 DOI: 10.3390/molecules23071599] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 06/21/2018] [Accepted: 06/28/2018] [Indexed: 12/31/2022] Open
Abstract
Reverse transcriptase inhibitors (RTIs), including nucleoside RTIs (NRTIs) and non-nucleoside RTIs (NNRTIs), are critical antiretroviral drugs for the treatment of human immunodeficiency virus (HIV) infection. Emergence of multi-RTI resistance calls for the development of more potent therapeutics or regimens against RTI-resistant strains. Here, we demonstrated that combining azidothymidine (AZT) with a new NNRTIs under development, diarylpyridine (DAPA)-2e, diarylanilin (DAAN)-14h, or DAAN-15h, resulted in strong synergism against infection by divergent HIV-1 strains, including those resistant to NRTIs and NNRTIs, suggesting the potential for developing these novel NNRTIs as salvage therapy for HIV/acquired immune deficiency syndrome (AIDS) patients.
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206
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Wang Y, Sun J, Zhu A, Zhao J, Zhao J. Current understanding of middle east respiratory syndrome coronavirus infection in human and animal models. J Thorac Dis 2018; 10:S2260-S2271. [PMID: 30116605 DOI: 10.21037/jtd.2018.03.80] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Middle East respiratory syndrome (MERS) is a highly lethal respiratory disease caused by a novel betacoronavirus (MERS coronavirus, MERS-CoV). Since its first emergence in 2012, multiple transmission events of MERS-CoV (dromedary to human and human to human) have been reported, indicating that MERS-CoV has the potential to cause widespread outbreak. However, the epidemiology of MERS as well as immune responses against the virus in animal models and patients are still not well understood, hindering the vaccine and therapeutic developments. In this review, we summarize recent genetic and epidemic findings of MERS-CoV and the progress in animal model development, immune response studies in both animals and humans. At last, we discussed the breakthrough on vaccine and therapeutic development which are important against potential future MERS outbreak.
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Affiliation(s)
- Yanqun Wang
- State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Health, the First Affiliated Hospital, Guangzhou 510120, China
| | - Jing Sun
- State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Health, the First Affiliated Hospital, Guangzhou 510120, China
| | - Airu Zhu
- State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Health, the First Affiliated Hospital, Guangzhou 510120, China
| | - Jingxian Zhao
- State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Health, the First Affiliated Hospital, Guangzhou 510120, China
| | - Jincun Zhao
- State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Health, the First Affiliated Hospital, Guangzhou 510120, China.,Institute of Infectious disease, Guangzhou Eighth People's Hospital of Guangzhou Medical University, Guangzhou 510120, China
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207
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Kandeel M, Al-Taher A, Li H, Schwingenschlogl U, Al-Nazawi M. Molecular dynamics of Middle East Respiratory Syndrome Coronavirus (MERS CoV) fusion heptad repeat trimers. Comput Biol Chem 2018; 75:205-212. [PMID: 29803965 PMCID: PMC7106505 DOI: 10.1016/j.compbiolchem.2018.05.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 05/13/2018] [Accepted: 05/16/2018] [Indexed: 12/23/2022]
Abstract
Virus-membrane fusion proteins have vital role in MERS CoV replication. Both trimers and monomers were found in both of virus and cell membranes. Changes in MERS CoV heptad repeat domains monomers and trimers were resolved by MD simulation. Monomer was unstable, having high RMSDs with major drifts above 8 Å. Trimer is more dynamically stable with very low RMSD.
Structural studies related to Middle East Respiratory Syndrome Coronavirus (MERS CoV) infection process are so limited. In this study, molecular dynamics (MD) simulations were carried out to unravel changes in the MERS CoV heptad repeat domains (HRs) and factors affecting fusion state HR stability. Results indicated that HR trimer is more rapidly stabilized, having stable system energy and lower root mean square deviations (RMSDs). While trimers were the predominant active form of CoVs HRs, monomers were also discovered in both of viral and cellular membranes. In order to find the differences between S2 monomer and trimer molecular dynamics, S2 monomer was modelled and subjected to MD simulation. In contrast to S2 trimer, S2 monomer was unstable, having high RMSDs with major drifts above 8 Å. Fluctuation of HR residue positions revealed major changes in the C-terminal of HR2 and the linker coil between HR1 and HR2 in both monomer and trimer. Hydrophobic residues at the a and d positions of HR helices stabilize the whole system, with minimal changes in RMSD. The global distance test and contact area difference scores support instability of MERS CoV S2 monomer. Analysis of HR1-HR2 inter-residue contacts and interaction energy revealed three energy scales along HR helices. Two strong interaction energies were identified at the start of the HR2 helix and at the C-terminal of HR2. The identified critical residues by MD simulation and residues at the a and d positions of HR helix were strong stabilizers of HR recognition.
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Affiliation(s)
- Mahmoud Kandeel
- Department of Physiology, Biochemistry and Pharmacology, Faculty of Veterinary Medicine, King Faisal University, Alhofuf, Alahsa, Saudi Arabia; Department of Pharmacology, Faculty of Veterinary Medicine, Kafrelshikh University, Kafrelshikh, Egypt.
| | - Abdulla Al-Taher
- Department of Physiology, Biochemistry and Pharmacology, Faculty of Veterinary Medicine, King Faisal University, Alhofuf, Alahsa, Saudi Arabia
| | - Huifang Li
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Udo Schwingenschlogl
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Mohamed Al-Nazawi
- Department of Physiology, Biochemistry and Pharmacology, Faculty of Veterinary Medicine, King Faisal University, Alhofuf, Alahsa, Saudi Arabia
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208
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Kim YS, Son A, Kim J, Kwon SB, Kim MH, Kim P, Kim J, Byun YH, Sung J, Lee J, Yu JE, Park C, Kim YS, Cho NH, Chang J, Seong BL. Chaperna-Mediated Assembly of Ferritin-Based Middle East Respiratory Syndrome-Coronavirus Nanoparticles. Front Immunol 2018; 9:1093. [PMID: 29868035 PMCID: PMC5966535 DOI: 10.3389/fimmu.2018.01093] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Accepted: 05/01/2018] [Indexed: 12/14/2022] Open
Abstract
The folding of monomeric antigens and their subsequent assembly into higher ordered structures are crucial for robust and effective production of nanoparticle (NP) vaccines in a timely and reproducible manner. Despite significant advances in in silico design and structure-based assembly, most engineered NPs are refractory to soluble expression and fail to assemble as designed, presenting major challenges in the manufacturing process. The failure is due to a lack of understanding of the kinetic pathways and enabling technical platforms to ensure successful folding of the monomer antigens into regular assemblages. Capitalizing on a novel function of RNA as a molecular chaperone (chaperna: chaperone + RNA), we provide a robust protein-folding vehicle that may be implemented to NP assembly in bacterial hosts. The receptor-binding domain (RBD) of Middle East respiratory syndrome-coronavirus (MERS-CoV) was fused with the RNA-interaction domain (RID) and bacterioferritin, and expressed in Escherichia coli in a soluble form. Site-specific proteolytic removal of the RID prompted the assemblage of monomers into NPs, which was confirmed by electron microscopy and dynamic light scattering. The mutations that affected the RNA binding to RBD significantly increased the soluble aggregation into amorphous structures, reducing the overall yield of NPs of a defined size. This underscored the RNA-antigen interactions during NP assembly. The sera after mouse immunization effectively interfered with the binding of MERS-CoV RBD to the cellular receptor hDPP4. The results suggest that RNA-binding controls the overall kinetic network of the antigen folding pathway in favor of enhanced assemblage of NPs into highly regular and immunologically relevant conformations. The concentration of the ion Fe2+, salt, and fusion linker also contributed to the assembly in vitro, and the stability of the NPs. The kinetic "pace-keeping" role of chaperna in the super molecular assembly of antigen monomers holds promise for the development and delivery of NPs and virus-like particles as recombinant vaccines and for serological detection of viral infections.
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Affiliation(s)
- Young-Seok Kim
- Department of Biotechnology, College of Life Sciences and Biotechnology, Yonsei University, Seoul, South Korea.,Vaccine Translational Research Center, Yonsei University, Seoul, South Korea
| | - Ahyun Son
- Department of Biotechnology, College of Life Sciences and Biotechnology, Yonsei University, Seoul, South Korea
| | - Jihoon Kim
- Department of Biotechnology, College of Life Sciences and Biotechnology, Yonsei University, Seoul, South Korea.,Vaccine Translational Research Center, Yonsei University, Seoul, South Korea
| | - Soon Bin Kwon
- Department of Biotechnology, College of Life Sciences and Biotechnology, Yonsei University, Seoul, South Korea.,Vaccine Translational Research Center, Yonsei University, Seoul, South Korea
| | - Myung Hee Kim
- Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul, South Korea
| | - Paul Kim
- Department of Biotechnology, College of Life Sciences and Biotechnology, Yonsei University, Seoul, South Korea.,Vaccine Translational Research Center, Yonsei University, Seoul, South Korea
| | - Jieun Kim
- Life Science and Biotechnology, Underwood International College, Yonsei University, Seoul, South Korea
| | - Young Ho Byun
- Department of Biotechnology, College of Life Sciences and Biotechnology, Yonsei University, Seoul, South Korea
| | - Jemin Sung
- Department of Biotechnology, College of Life Sciences and Biotechnology, Yonsei University, Seoul, South Korea.,Vaccine Translational Research Center, Yonsei University, Seoul, South Korea
| | - Jinhee Lee
- Department of Biotechnology, College of Life Sciences and Biotechnology, Yonsei University, Seoul, South Korea.,Vaccine Translational Research Center, Yonsei University, Seoul, South Korea
| | - Ji Eun Yu
- Department of Biotechnology, College of Life Sciences and Biotechnology, Yonsei University, Seoul, South Korea.,Vaccine Translational Research Center, Yonsei University, Seoul, South Korea
| | - Chan Park
- Department of Biotechnology, College of Life Sciences and Biotechnology, Yonsei University, Seoul, South Korea.,Vaccine Translational Research Center, Yonsei University, Seoul, South Korea
| | - Yeon-Sook Kim
- Division of Infectious Diseases, Department of Internal Medicine, Chungnam National University School of Medicine, Daejeon, South Korea
| | - Nam-Hyuk Cho
- Department of Microbiology and Immunology, Seoul National University College of Medicine, Seoul, South Korea.,Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, South Korea
| | - Jun Chang
- Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul, South Korea
| | - Baik L Seong
- Department of Biotechnology, College of Life Sciences and Biotechnology, Yonsei University, Seoul, South Korea.,Vaccine Translational Research Center, Yonsei University, Seoul, South Korea
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209
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Rumlová M, Ruml T. In vitro methods for testing antiviral drugs. Biotechnol Adv 2018; 36:557-576. [PMID: 29292156 PMCID: PMC7127693 DOI: 10.1016/j.biotechadv.2017.12.016] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 12/22/2017] [Accepted: 12/27/2017] [Indexed: 12/24/2022]
Abstract
Despite successful vaccination programs and effective treatments for some viral infections, humans are still losing the battle with viruses. Persisting human pandemics, emerging and re-emerging viruses, and evolution of drug-resistant strains impose continuous search for new antiviral drugs. A combination of detailed information about the molecular organization of viruses and progress in molecular biology and computer technologies has enabled rational antivirals design. Initial step in establishing efficacy of new antivirals is based on simple methods assessing inhibition of the intended target. We provide here an overview of biochemical and cell-based assays evaluating the activity of inhibitors of clinically important viruses.
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Affiliation(s)
- Michaela Rumlová
- Department of Biotechnology, University of Chemistry and Technology, Prague 166 28, Czech Republic.
| | - Tomáš Ruml
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague 166 28, Czech Republic.
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210
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Shang J, Zheng Y, Yang Y, Liu C, Geng Q, Luo C, Zhang W, Li F. Cryo-EM structure of infectious bronchitis coronavirus spike protein reveals structural and functional evolution of coronavirus spike proteins. PLoS Pathog 2018; 14:e1007009. [PMID: 29684066 PMCID: PMC5933801 DOI: 10.1371/journal.ppat.1007009] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 05/03/2018] [Accepted: 04/03/2018] [Indexed: 01/08/2023] Open
Abstract
As cell-invading molecular machinery, coronavirus spike proteins pose an evolutionary conundrum due to their high divergence. In this study, we determined the cryo-EM structure of avian infectious bronchitis coronavirus (IBV) spike protein from the γ-genus. The trimeric IBV spike ectodomain contains three receptor-binding S1 heads and a trimeric membrane-fusion S2 stalk. While IBV S2 is structurally similar to those from the other genera, IBV S1 possesses structural features that are unique to different other genera, thereby bridging these diverse spikes into an evolutionary spectrum. Specifically, among different genera, the two domains of S1, the N-terminal domain (S1-NTD) and C-terminal domain (S1-CTD), diverge from simpler tertiary structures and quaternary packing to more complex ones, leading to different functions of the spikes in receptor usage and membrane fusion. Based on the above structural and functional comparisons, we propose that the evolutionary spectrum of coronavirus spikes follows the order of α-, δ-, γ-, and β-genus. This study has provided insight into the evolutionary relationships among coronavirus spikes and deepened our understanding of their structural and functional diversity.
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Affiliation(s)
- Jian Shang
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN, United States of America
| | - Yuan Zheng
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN, United States of America
| | - Yang Yang
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN, United States of America
| | - Chang Liu
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN, United States of America
| | - Qibin Geng
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN, United States of America
| | - Chuming Luo
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN, United States of America
| | - Wei Zhang
- Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN, United States of America
- Characterization Facility, College of Science and Engineering, University of Minnesota, Minneapolis, MN, United States of America
| | - Fang Li
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN, United States of America
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211
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Al-Qahtani AA, Lyroni K, Aznaourova M, Tseliou M, Al-Anazi MR, Al-Ahdal MN, Alkahtani S, Sourvinos G, Tsatsanis C. Middle east respiratory syndrome corona virus spike glycoprotein suppresses macrophage responses via DPP4-mediated induction of IRAK-M and PPARγ. Oncotarget 2018; 8:9053-9066. [PMID: 28118607 PMCID: PMC5354714 DOI: 10.18632/oncotarget.14754] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 01/10/2017] [Indexed: 12/23/2022] Open
Abstract
Middle East Respiratory Syndrome Corona Virus (MERS-CoV) is transmitted via the respiratory tract and causes severe Acute Respiratory Distress Syndrome by infecting lung epithelial cells and macrophages. Macrophages can readily recognize the virus and eliminate it. MERS-CoV infects cells via its Spike (S) glycoprotein that binds on Dipeptidyl-Peptidase 4 (DPP4) receptor present on macrophages. Whether this Spike/DPP4 association affects macrophage responses remains unknown. Herein we demonstrated that infection of macrophages with lentiviral particles pseudotyped with MERS-CoV S glycoprotein results in suppression of macrophage responses since it reduced the capacity of macrophages to produce TNFα and IL-6 in naive and LPS-activated THP-1 macrophages and augmented LPS-induced production of the immunosuppressive cytokine IL-10. MERS-CoV S glycoprotein induced the expression of the negative regulator of TLR signaling IRAK-M as well as of the transcriptional repressor PPARγ. Inhibition of DPP4 by its inhibitor sitagliptin or siRNA abrogated the effects of MERS-CoV S glycoprotein on IRAK-M, PPARγ and IL-10, confirming that its immunosuppressive effects were mediated by DPP4 receptor. The effect was observed both in THP-1 macrophages and human primary peripheral blood monocytes. These findings support a DPP4-mediated suppressive action of MERS-CoV in macrophages and suggest a potential target for effective elimination of its pathogenicity.
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Affiliation(s)
- Ahmed A Al-Qahtani
- Department of Infection and Immunity, Research Center, King Faisal Specialist Hospital and Research Center, Saudi Arabia.,Department of Microbiology and Immunology, School of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Konstantina Lyroni
- Laboratory of Clinical Chemistry, Medical School, University of Crete, Heraklion, Greece
| | - Marina Aznaourova
- Laboratory of Clinical Chemistry, Medical School, University of Crete, Heraklion, Greece
| | - Melpomeni Tseliou
- Laboratory of Virology, Medical School, University of Crete, Heraklion, Greece
| | - Mashael R Al-Anazi
- Department of Infection and Immunity, Research Center, King Faisal Specialist Hospital and Research Center, Saudi Arabia
| | - Mohammed N Al-Ahdal
- Department of Infection and Immunity, Research Center, King Faisal Specialist Hospital and Research Center, Saudi Arabia.,Department of Microbiology and Immunology, School of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Saad Alkahtani
- Zoology Department, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - George Sourvinos
- Laboratory of Virology, Medical School, University of Crete, Heraklion, Greece
| | - Christos Tsatsanis
- Laboratory of Clinical Chemistry, Medical School, University of Crete, Heraklion, Greece
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212
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Wang C, Xia S, Zhang P, Zhang T, Wang W, Tian Y, Meng G, Jiang S, Liu K. Discovery of Hydrocarbon-Stapled Short α-Helical Peptides as Promising Middle East Respiratory Syndrome Coronavirus (MERS-CoV) Fusion Inhibitors. J Med Chem 2018; 61:2018-2026. [PMID: 29442512 PMCID: PMC7075646 DOI: 10.1021/acs.jmedchem.7b01732] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The hexameric α-helical coiled-coil formed between the C-terminal and N-terminal heptad repeat (CHR and NHR) regions of class I viral fusion proteins plays an important role in mediating the fusion of the viral and cellular membranes and provides a clear starting point for molecular mimicry that drives viral fusion inhibitor design. Unfortunately, such peptide mimicry of the short α-helical region in the CHR of Middle East respiratory syndrome coronavirus (MERS-CoV) spike protein has been thwarted by the loss of the peptide's native α-helical conformation when taken out of the parent protein structure. Here, we describe that appropriate all-hydrocarbon stapling of the short helical portion-based peptide to reinforce its bioactive secondary structure remarkably improves antiviral potency. The resultant stapled peptide P21S10 could effectively inhibit infection by MERS-CoV pseudovirus and its spike protein-mediated cell-cell fusion; additionally, P21S10 exhibits improved pharmacokinetic properties than HR2P-M2, suggesting strong potential for development as an anti-MERS-CoV therapeutic.
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Affiliation(s)
- Chao Wang
- State Key Laboratory of Toxicology and Medical Countermeasures , Beijing Institute of Pharmacology and Toxicology , 27 Tai-Ping Road , Beijing 100850 , China
| | - Shuai Xia
- Key Laboratory of Medical Molecular Virology of MOE/MOH, School of Basic Medical Sciences and Shanghai Public Health Clinical Center , Fudan University , 130 Dong An Road , Shanghai 200032 , China
| | - Peiyu Zhang
- Key Laboratory of Structure-Based Drug Design and Discovery of the Ministry of Education , Shenyang Pharmaceutical University , Shenyang 110016 , China
| | - Tianhong Zhang
- State Key Laboratory of Toxicology and Medical Countermeasures , Beijing Institute of Pharmacology and Toxicology , 27 Tai-Ping Road , Beijing 100850 , China
| | - Weicong Wang
- Pharmaceutical Preparation Section, Plastic Surgery Hospital , Chinese Academy of Medical Sciences and Peking Union Medical College , Beijing 100144 , China
| | - Yangli Tian
- State Key Laboratory of Toxicology and Medical Countermeasures , Beijing Institute of Pharmacology and Toxicology , 27 Tai-Ping Road , Beijing 100850 , China
| | - Guangpeng Meng
- Key Laboratory of Structure-Based Drug Design and Discovery of the Ministry of Education , Shenyang Pharmaceutical University , Shenyang 110016 , China
| | - Shibo Jiang
- Key Laboratory of Medical Molecular Virology of MOE/MOH, School of Basic Medical Sciences and Shanghai Public Health Clinical Center , Fudan University , 130 Dong An Road , Shanghai 200032 , China.,Lindsley F. Kimball Research Institute , New York Blood Center , New York , New York 10065 , United States
| | - Keliang Liu
- State Key Laboratory of Toxicology and Medical Countermeasures , Beijing Institute of Pharmacology and Toxicology , 27 Tai-Ping Road , Beijing 100850 , China.,Key Laboratory of Structure-Based Drug Design and Discovery of the Ministry of Education , Shenyang Pharmaceutical University , Shenyang 110016 , China
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213
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Böttcher-Friebertshäuser E, Garten W, Klenk HD. Priming Time: How Cellular Proteases Arm Coronavirus Spike Proteins. ACTIVATION OF VIRUSES BY HOST PROTEASES 2018. [PMCID: PMC7122371 DOI: 10.1007/978-3-319-75474-1_4] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Coronaviruses are enveloped RNA viruses that infect mammals and birds. Infection of humans with globally circulating human coronaviruses is associated with the common cold. In contrast, transmission of animal coronaviruses to humans can result in severe disease: The severe acute respiratory syndrome (SARS) and the Middle East respiratory syndrome (MERS) are responsible for hundreds of deaths in Asia and the Middle East, respectively, and are both caused by members of the genus Betacoronavirus, SARS-CoV, and MERS-CoV that were zoonotically transmitted from an animal host to humans. At present, neither vaccines nor specific treatment is available to combat coronavirus infection in humans, and novel antiviral strategies are urgently sought. The viral spike protein (S) mediates the first essential step in coronavirus infection, viral entry into target cells. For this, the S protein critically depends on priming by host cell proteases, and the responsible enzymes are potential targets for antiviral intervention. Recent studies revealed that the endosomal cysteine protease cathepsin L and the serine proteases furin and TMPRSS2 prime the S proteins of SARS-CoV and MERS-CoV and provided evidence that successive S protein cleavage at two sites is required for S protein priming. Moreover, mechanisms that control protease choice were unraveled, and insights were obtained into which enzyme promotes viral spread in the host. Here, we will provide basic information on S protein function and proteolytic priming, and we will then discuss recent progress in our understanding of the priming of the S proteins of SARS-CoV and MERS-CoV.
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Affiliation(s)
| | - Wolfgang Garten
- Institut für Virologie, Philipps Universität, Marburg, Germany
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214
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Xia S, Xu W, Wang Q, Wang C, Hua C, Li W, Lu L, Jiang S. Peptide-Based Membrane Fusion Inhibitors Targeting HCoV-229E Spike Protein HR1 and HR2 Domains. Int J Mol Sci 2018; 19:ijms19020487. [PMID: 29415501 PMCID: PMC5855709 DOI: 10.3390/ijms19020487] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 01/24/2018] [Accepted: 01/31/2018] [Indexed: 12/11/2022] Open
Abstract
Human coronavirus 229E (HCoV-229E) infection in infants, elderly people, and immunocompromised patients can cause severe disease, thus calling for the development of effective and safe therapeutics to treat it. Here we reported the design, synthesis and characterization of two peptide-based membrane fusion inhibitors targeting HCoV-229E spike protein heptad repeat 1 (HR1) and heptad repeat 2 (HR2) domains, 229E-HR1P and 229E-HR2P, respectively. We found that 229E-HR1P and 229E-HR2P could interact to form a stable six-helix bundle and inhibit HCoV-229E spike protein-mediated cell-cell fusion with IC50 of 5.7 and 0.3 µM, respectively. 229E-HR2P effectively inhibited pseudotyped and live HCoV-229E infection with IC50 of 0.5 and 1.7 µM, respectively. In a mouse model, 229E-HR2P administered intranasally could widely distribute in the upper and lower respiratory tracts and maintain its fusion-inhibitory activity. Therefore, 229E-HR2P is a promising candidate for further development as an antiviral agent for the treatment and prevention of HCoV-229E infection.
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Affiliation(s)
- Shuai Xia
- Key Laboratory of Medical Molecular Virology of MOE/MOH, School of Basic Medical Sciences & Shanghai Public Health Clinical Center, Fudan University, 130 Dong An Rd., Xuhui District, Shanghai 200032, China.
| | - Wei Xu
- Key Laboratory of Medical Molecular Virology of MOE/MOH, School of Basic Medical Sciences & Shanghai Public Health Clinical Center, Fudan University, 130 Dong An Rd., Xuhui District, Shanghai 200032, China.
| | - Qian Wang
- Key Laboratory of Medical Molecular Virology of MOE/MOH, School of Basic Medical Sciences & Shanghai Public Health Clinical Center, Fudan University, 130 Dong An Rd., Xuhui District, Shanghai 200032, China.
| | - Cong Wang
- Key Laboratory of Medical Molecular Virology of MOE/MOH, School of Basic Medical Sciences & Shanghai Public Health Clinical Center, Fudan University, 130 Dong An Rd., Xuhui District, Shanghai 200032, China.
| | - Chen Hua
- Key Laboratory of Medical Molecular Virology of MOE/MOH, School of Basic Medical Sciences & Shanghai Public Health Clinical Center, Fudan University, 130 Dong An Rd., Xuhui District, Shanghai 200032, China.
| | - Weihua Li
- Key Laboratory of Reproduction Regulation of National Population and Family Planning Commission, The Shanghai Institute of Planned Parenthood Research, Institute of Reproduction and Development, Fudan University, Shanghai 200032, China.
| | - Lu Lu
- Key Laboratory of Medical Molecular Virology of MOE/MOH, School of Basic Medical Sciences & Shanghai Public Health Clinical Center, Fudan University, 130 Dong An Rd., Xuhui District, Shanghai 200032, China.
| | - Shibo Jiang
- Key Laboratory of Medical Molecular Virology of MOE/MOH, School of Basic Medical Sciences & Shanghai Public Health Clinical Center, Fudan University, 130 Dong An Rd., Xuhui District, Shanghai 200032, China.
- Key Laboratory of Reproduction Regulation of National Population and Family Planning Commission, The Shanghai Institute of Planned Parenthood Research, Institute of Reproduction and Development, Fudan University, Shanghai 200032, China.
- Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY 10065, USA.
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215
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Mahajan M, Chatterjee D, Bhuvaneswari K, Pillay S, Bhattacharjya S. NMR structure and localization of a large fragment of the SARS-CoV fusion protein: Implications in viral cell fusion. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2018; 1860:407-415. [PMID: 28988778 PMCID: PMC7094225 DOI: 10.1016/j.bbamem.2017.10.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 09/16/2017] [Accepted: 10/03/2017] [Indexed: 01/20/2023]
Abstract
The lethal Coronaviruses (CoVs), Severe Acute Respiratory Syndrome-associated Coronavirus (SARS-CoV) and most recently Middle East Respiratory Syndrome Coronavirus, (MERS-CoV) are serious human health hazard. A successful viral infection requires fusion between virus and host cells carried out by the surface spike glycoprotein or S protein of CoV. Current models propose that the S2 subunit of S protein assembled into a hexameric helical bundle exposing hydrophobic fusogenic peptides or fusion peptides (FPs) for membrane insertion. The N-terminus of S2 subunit of SARS-CoV reported to be active in cell fusion whereby FPs have been identified. Atomic-resolution structure of FPs derived either in model membranes or in membrane mimic environment would glean insights toward viral cell fusion mechanism. Here, we have solved 3D structure, dynamics and micelle localization of a 64-residue long fusion peptide or LFP in DPC detergent micelles by NMR methods. Micelle bound structure of LFP is elucidated by the presence of discretely folded helical and intervening loops. The C-terminus region, residues F42-Y62, displays a long hydrophobic helix, whereas the N-terminus is defined by a short amphipathic helix, residues R4-Q12. The intervening residues of LFP assume stretches of loops and helical turns. The N-terminal helix is sustained by close aromatic and aliphatic sidechain packing interactions at the non-polar face. 15N{1H}NOE studies indicated dynamical motion, at ps-ns timescale, of the helices of LFP in DPC micelles. PRE NMR showed that insertion of several regions of LFP into DPC micelle core. Together, the current study provides insights toward fusion mechanism of SARS-CoV.
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Affiliation(s)
- Mukesh Mahajan
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Deepak Chatterjee
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Kannaian Bhuvaneswari
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Shubhadra Pillay
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Surajit Bhattacharjya
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore.
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216
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Excler JL, Delvecchio CJ, Wiley RE, Williams M, Yoon IK, Modjarrad K, Boujelal M, Moorthy VS, Hersi AS, Kim JH. Toward Developing a Preventive MERS-CoV Vaccine-Report from a Workshop Organized by the Saudi Arabia Ministry of Health and the International Vaccine Institute, Riyadh, Saudi Arabia, November 14-15, 2015. Emerg Infect Dis 2018; 22. [PMID: 27439020 PMCID: PMC4982192 DOI: 10.3201/eid2208.160229] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Middle East respiratory syndrome (MERS) remains a serious international public health threat. With the goal of accelerating the development of countermeasures against MERS coronavirus (MERS-CoV), funding agencies, nongovernmental organizations, and researchers across the world assembled in Riyadh, Saudi Arabia, on November 14-15, 2015, to discuss vaccine development challenges. The meeting was spearheaded by the Saudi Ministry of Health and co-organized by the International Vaccine Institute, South Korea. Accelerating the development of a preventive vaccine requires a better understanding of MERS epidemiology, transmission, and pathogenesis in humans and animals. A combination of rodent and nonhuman primate models should be considered in evaluating and developing preventive and therapeutic vaccine candidates. Dromedary camels should be considered for the development of veterinary vaccines. Several vaccine technology platforms targeting the MERS-CoV spike protein were discussed. Mechanisms to maximize investment, provide robust data, and affect public health are urgently needed.
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217
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McKimm-Breschkin JL, Jiang S, Hui DS, Beigel JH, Govorkova EA, Lee N. Prevention and treatment of respiratory viral infections: Presentations on antivirals, traditional therapies and host-directed interventions at the 5th ISIRV Antiviral Group conference. Antiviral Res 2018; 149:118-142. [PMID: 29162476 PMCID: PMC7133686 DOI: 10.1016/j.antiviral.2017.11.013] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 11/14/2017] [Indexed: 12/17/2022]
Abstract
The International Society for Influenza and other Respiratory Virus Diseases held its 5th Antiviral Group (isirv-AVG) Conference in Shanghai, China, in conjunction with the Shanghai Public Health Center and Fudan University from 14-16 June 2017. The three-day programme encompassed presentations on some of the clinical features, management, immune responses and virology of respiratory infections, including influenza A(H1N1)pdm09 and A(H7N9) viruses, MERS-CoV, SARS-CoV, adenovirus Type 80, enterovirus D68, metapneumovirus and respiratory syncytial virus (RSV). Updates were presented on several therapeutics currently in clinical trials, including influenza polymerase inhibitors pimodivir/JNJ6362387, S033188, favipiravir, monoclonal antibodies MHAA45449A and VIS410, and host directed strategies for influenza including nitazoxanide, and polymerase ALS-008112 and fusion inhibitors AK0529, GS-5806 for RSV. Updates were also given on the use of the currently licensed neuraminidase inhibitors. Given the location in China, there were also presentations on the use of Traditional Chinese Medicines. Following on from the previous conference, there were ongoing discussions on appropriate endpoints for severe influenza in clinical trials from regulators and clinicians, an issue which remains unresolved. The aim of this conference summary is to provide information for not only conference participants, but a detailed referenced review of the current status of clinical trials, and pre-clinical development of therapeutics and vaccines for influenza and other respiratory diseases for a broader audience.
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Affiliation(s)
| | - Shibo Jiang
- College of Basic Medical Sciences, Fudan University, Shanghai, China; Lindsley F. Kimball Research Institute, New York Blood Center, NY, USA
| | - David S Hui
- Department of Medicine and Therapeutics, Chinese University of Hong Kong, Hong Kong Special Administrative Region
| | - John H Beigel
- Leidos Biomedical Research, Inc., Support to National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIH), Bethesda, MD, USA
| | - Elena A Govorkova
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, USA
| | - Nelson Lee
- Faculty of Medicine and Dentistry, University of Alberta, Canada
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218
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Identification of a peptide derived from the heptad repeat 2 region of the porcine epidemic diarrhea virus (PEDV) spike glycoprotein that is capable of suppressing PEDV entry and inducing neutralizing antibodies. Antiviral Res 2017; 150:1-8. [PMID: 29203391 PMCID: PMC7113693 DOI: 10.1016/j.antiviral.2017.11.021] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 11/29/2017] [Accepted: 11/30/2017] [Indexed: 12/22/2022]
Abstract
Heptad repeat (HR) regions are highly conserved motifs located in the glycoproteins of enveloped viruses that form a six-helix bundle structure and is important in the process of virus fusion. Peptides derived from the HR regions of some viruses have also been shown to inhibit viral entry. Porcine epidemic diarrhea virus (PEDV) was predicted to have HR regions (HR1 and HR2) in the spike glycoprotein S2 subunit. Based on this analysis, six peptides derived from HR1 and HR2 were selected, expressed in Escherichia coli, purified, and characterized. Three peptides (HR2M, HR2L and HR2P) were identified as potential competitive inhibitors in PEDV in vitro infection assays, with the HR2P peptide representing the most potent inhibitor. Further study indicated that immunization of HR2P in mice elicited antibodies capable of neutralizing PEDV infection in vitro. These results demonstrate that the HR2P peptide and anti-HR2P antibody can serve as a tool for dissecting the fusion mechanism of PEDV, guiding the search for potent inhibitors with therapeutic value against PEDV infection. Six peptides derived from heptad repeat (HR) 1 and 2 regions of PEDV S glycoprotein were expressed and characterized. Three peptides (HR2M, HR2L and HR2P) exhibited antiviral activity in vitro. Immunization of the HR2P peptide in mice elicited antibodies capable of neutralizing PEDV infection in vitro. HR2P peptide can serve as a potential antiviral drug against PEDV infection.
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219
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Dyall J, Gross R, Kindrachuk J, Johnson RF, Olinger GG, Hensley LE, Frieman MB, Jahrling PB. Middle East Respiratory Syndrome and Severe Acute Respiratory Syndrome: Current Therapeutic Options and Potential Targets for Novel Therapies. Drugs 2017; 77:1935-1966. [PMID: 29143192 PMCID: PMC5733787 DOI: 10.1007/s40265-017-0830-1] [Citation(s) in RCA: 125] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
No specific antivirals are currently available for two emerging infectious diseases, Middle East respiratory syndrome (MERS) and severe acute respiratory syndrome (SARS). A literature search was performed covering pathogenesis, clinical features and therapeutics, clinically developed drugs for repurposing and novel drug targets. This review presents current knowledge on the epidemiology, pathogenesis and clinical features of the SARS and MERS coronaviruses. The rationale for and outcomes with treatments used for SARS and MERS is discussed. The main focus of the review is on drug development and the potential that drugs approved for other indications provide for repurposing. The drugs we discuss belong to a wide range of different drug classes, such as cancer therapeutics, antipsychotics, and antimalarials. In addition to their activity against MERS and SARS coronaviruses, many of these approved drugs have broad-spectrum potential and have already been in clinical use for treating other viral infections. A wealth of knowledge is available for these drugs. However, the information in this review is not meant to guide clinical decisions, and any therapeutic described here should only be used in context of a clinical trial. Potential targets for novel antivirals and antibodies are discussed as well as lessons learned from treatment development for other RNA viruses. The article concludes with a discussion of the gaps in our knowledge and areas for future research on emerging coronaviruses.
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Affiliation(s)
- Julie Dyall
- Integrated Research Facility, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD, USA.
| | - Robin Gross
- Integrated Research Facility, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD, USA
| | - Jason Kindrachuk
- Department of Medical Microbiology, University of Manitoba, Winnipeg, MN, Canada
| | - Reed F Johnson
- Emerging Viral Pathogens Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD, USA
| | | | - Lisa E Hensley
- Integrated Research Facility, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD, USA
| | - Matthew B Frieman
- Department of Microbiology and Immunology, University of Maryland, School of Medicine, Baltimore, MD, USA
| | - Peter B Jahrling
- Integrated Research Facility, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD, USA
- Emerging Viral Pathogens Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD, USA
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220
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Development of small-molecule viral inhibitors targeting various stages of the life cycle of emerging and re-emerging viruses. Front Med 2017; 11:449-461. [PMID: 29170916 PMCID: PMC7089273 DOI: 10.1007/s11684-017-0589-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 09/22/2017] [Indexed: 01/22/2023]
Abstract
In recent years, unexpected outbreaks of infectious diseases caused by emerging and re-emerging viruses have become more frequent, which is possibly due to environmental changes. These outbreaks result in the loss of life and economic hardship. Vaccines and therapeutics should be developed for the prevention and treatment of infectious diseases. In this review, we summarize and discuss the latest progress in the development of small-molecule viral inhibitors against highly pathogenic coronaviruses, including severe acute respiratory syndrome coronavirus and Middle East respiratory syndrome coronavirus, Ebola virus, and Zika virus. These viruses can interfere with the specific steps of viral life cycle by blocking the binding between virus and host cells, disrupting viral endocytosis, disturbing membrane fusion, and interrupting viral RNA replication and translation, thereby demonstrating potent therapeutic effect against various emerging and re-emerging viruses. We also discuss some general strategies for developing small-molecule viral inhibitors.
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221
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Sun Y, Zhang H, Shi J, Zhang Z, Gong R. Identification of a Novel Inhibitor against Middle East Respiratory Syndrome Coronavirus. Viruses 2017; 9:v9090255. [PMID: 28906430 PMCID: PMC5618021 DOI: 10.3390/v9090255] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 09/05/2017] [Accepted: 09/06/2017] [Indexed: 12/28/2022] Open
Abstract
The Middle East respiratory syndrome coronavirus (MERS-CoV) was first isolated in 2012, and circulated worldwide with high mortality. The continual outbreaks of MERS-CoV highlight the importance of developing antiviral therapeutics. Here, we rationally designed a novel fusion inhibitor named MERS-five-helix bundle (MERS-5HB) derived from the six-helix bundle (MERS-6HB) which was formed by the process of membrane fusion. MERS-5HB consists of three copies of heptad repeat 1 (HR1) and two copies of heptad repeat 2 (HR2) while MERS-6HB includes three copies each of HR1 and HR2. As it lacks one HR2, MERS-5HB was expected to interact with viral HR2 to interrupt the fusion step. What we found was that MERS-5HB could bind to HR2P, a peptide derived from HR2, with a strong affinity value (KD) of up to 0.24 nM. Subsequent assays indicated that MERS-5HB could inhibit pseudotyped MERS-CoV entry effectively with 50% inhibitory concentration (IC50) of about 1 μM. In addition, MERS-5HB significantly inhibited spike (S) glycoprotein-mediated syncytial formation in a dose-dependent manner. Further biophysical characterization showed that MERS-5HB was a thermo-stable α-helical secondary structure. The inhibitory potency of MERS-5HB may provide an attractive basis for identification of a novel inhibitor against MERS-CoV, as a potential antiviral agent.
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Affiliation(s)
- Yaping Sun
- Center for Emerging Infectious Diseases, CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, No. 44 Xiao Hong Shan, Wuhan 430071, China.
- University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Huaidong Zhang
- Center for Emerging Infectious Diseases, CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, No. 44 Xiao Hong Shan, Wuhan 430071, China.
| | - Jian Shi
- Center for Emerging Infectious Diseases, CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, No. 44 Xiao Hong Shan, Wuhan 430071, China.
| | - Zhe Zhang
- Center for Emerging Infectious Diseases, CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, No. 44 Xiao Hong Shan, Wuhan 430071, China.
| | - Rui Gong
- Center for Emerging Infectious Diseases, CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, No. 44 Xiao Hong Shan, Wuhan 430071, China.
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222
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Mustafa S, Balkhy H, Gabere MN. Current treatment options and the role of peptides as potential therapeutic components for Middle East Respiratory Syndrome (MERS): A review. J Infect Public Health 2017; 11:9-17. [PMID: 28864360 PMCID: PMC7102797 DOI: 10.1016/j.jiph.2017.08.009] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 08/07/2017] [Accepted: 08/11/2017] [Indexed: 02/07/2023] Open
Abstract
Middle East Respiratory Syndrome Coronavirus (MERS-CoV) is a highly pathogenic respiratory virus with mechanisms that may be driven by innate immune responses. Despite the effort of scientific studies related to this virus, Middle East Respiratory Syndrome (MERS) is still a public health concern. MERS-CoV infection has a high mortality rate, and to date, no therapeutic or vaccine has been discovered, that is effective in treating or preventing the disease. In this review, we summarize our understanding of the molecular and biological events of compounds acting as MERS-CoV inhibitors, the outcomes of existing therapeutic options and the various drugs undergoing clinical trials. Currently, several therapeutic options have been employed, such as convalescent plasma (CP), intravenous immunoglobulin (IVIG), monoclonal antibodies and repurposing of existing clinically approved drugs. However, these therapeutic options have drawbacks, thus the need for an alternative approach. The requirement for effective therapeutic treatment has brought the necessity for additional MERS treatments. We suggest that antimicrobial peptides (AMPs) may be used as alternative therapeutic agents against MERS-CoV infection. In addition, we propose the feasibility of developing effective agents by repurposing the existing and clinically approved anti-coronavirus and anti-viral peptide drugs.
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Affiliation(s)
- Sabeena Mustafa
- Department of Biostatistics and Bioinformatics, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, P.O. Box 22490, Mail Code 1515, Riyadh 11426, Saudi Arabia
| | - Hanan Balkhy
- Infection Prevention and Control Department at the Ministry of National Guard, Department of Infectious Diseases, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, P.O. Box 22490, Mail Code 1515, Riyadh 11426, Saudi Arabia
| | - Musa N Gabere
- Department of Biostatistics and Bioinformatics, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, P.O. Box 22490, Mail Code 1515, Riyadh 11426, Saudi Arabia.
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223
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Rabaan AA, Alahmed SH, Bazzi AM, Alhani HM. A review of candidate therapies for Middle East respiratory syndrome from a molecular perspective. J Med Microbiol 2017; 66:1261-1274. [PMID: 28855003 PMCID: PMC7079582 DOI: 10.1099/jmm.0.000565] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
There have been 2040 laboratory-confirmed cases of Middle East respiratory syndrome coronavirus (MERS-CoV) in 27 countries, with a mortality rate of 34.9 %. There is no specific therapy. The current therapies have mainly been adapted from severe acute respiratory syndrome (SARS-CoV) treatments, including broad-spectrum antibiotics, corticosteroids, interferons, ribavirin, lopinavir–ritonavir or mycophenolate mofetil, and have not been subject to well-organized clinical trials. The development of specific therapies and vaccines is therefore urgently required. We examine existing and potential therapies and vaccines from a molecular perspective. These include viral S protein targeting; inhibitors of host proteases, including TMPRSS2, cathepsin L and furin protease, and of viral M(pro) and the PL(pro) proteases; convalescent plasma; and vaccine candidates. The Medline database was searched using combinations and variations of terms, including ‘Middle East respiratory syndrome coronavirus’, ‘MERS-CoV’, ‘SARS’, ‘therapy’, ‘molecular’, ‘vaccine’, ‘prophylactic’, ‘S protein’, ‘DPP4’, ‘heptad repeat’, ‘protease’, ‘inhibitor’, ‘anti-viral’, ‘broad-spectrum’, ‘interferon’, ‘convalescent plasma’, ‘lopinavir ritonavir’, ‘antibodies’, ‘antiviral peptides’ and ‘live attenuated viruses’. There are many options for the development of MERS-CoV-specific therapies. Currently, MERS-CoV is not considered to have pandemic potential. However, the high mortality rate and potential for mutations that could increase transmissibility give urgency to the search for direct, effective therapies. Well-designed and controlled clinical trials are needed, both for existing therapies and for prospective direct therapies.
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Affiliation(s)
- Ali A Rabaan
- Molecular Diagnostic Laboratory, Johns Hopkins Aramco Healthcare, Dhahran 31311, Saudi Arabia
| | - Shamsah H Alahmed
- Specialty Paediatric Medicine, Qatif Central Hospital, Qatif 32654, Saudi Arabia
| | - Ali M Bazzi
- Microbiology Laboratory, Johns Hopkins Aramco Healthcare, Dhahran 31311, Saudi Arabia
| | - Hatem M Alhani
- Maternity and Children Hospital, and Directorate of Infection Control at Eastern Province, Ministry of Health, Dammam, Saudi Arabia
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224
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Park JE, Gallagher T. Lipidation increases antiviral activities of coronavirus fusion-inhibiting peptides. Virology 2017; 511:9-18. [PMID: 28802158 PMCID: PMC7112077 DOI: 10.1016/j.virol.2017.07.033] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 07/25/2017] [Accepted: 07/27/2017] [Indexed: 11/30/2022]
Abstract
Coronaviruses (CoVs) can cause life-threatening respiratory diseases. Their infectious entry requires viral spike (S) proteins, which attach to cell receptors, undergo proteolytic cleavage, and then refold in a process that catalyzes virus-cell membrane fusion. Fusion-inhibiting peptides bind to S proteins, interfere with refolding, and prevent infection. Here we conjugated fusion-inhibiting peptides to various lipids, expecting this to secure peptides onto cell membranes and thereby increase antiviral potencies. Cholesterol or palmitate adducts increased antiviral potencies up to 1000-fold. Antiviral effects were evident after S proteolytic cleavage, implying that lipid conjugates affixed the peptides at sites of protease-triggered fusion activation. Unlike lipid-free peptides, the lipopeptides suppressed CoV S protein-directed virus entry taking place within endosomes. Cell imaging revealed intracellular peptide aggregates, consistent with their endocytosis into compartments where CoV entry takes place. These findings suggest that lipidations localize antiviral peptides to protease-rich sites of CoV fusion, thereby protecting cells from diverse CoVs. Lipidation increases antiviral activities of CoV fusion-inhibiting peptides. Fusion-inhibiting peptides target proteolytically-triggered CoV spike proteins. Lipidated peptides suppress CoVs that are occluded within endosomes before cytosolic entry.
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Affiliation(s)
- Jung-Eun Park
- Department of Microbiology and Immunology, Loyola University Chicago, Maywood, IL 60153, USA
| | - Tom Gallagher
- Department of Microbiology and Immunology, Loyola University Chicago, Maywood, IL 60153, USA.
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225
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Yu Y, Deng YQ, Zou P, Wang Q, Dai Y, Yu F, Du L, Zhang NN, Tian M, Hao JN, Meng Y, Li Y, Zhou X, Fuk-Woo Chan J, Yuen KY, Qin CF, Jiang S, Lu L. A peptide-based viral inactivator inhibits Zika virus infection in pregnant mice and fetuses. Nat Commun 2017; 8:15672. [PMID: 28742068 PMCID: PMC5537589 DOI: 10.1038/ncomms15672] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 04/17/2017] [Indexed: 11/26/2022] Open
Abstract
Zika virus (ZIKV), a re-emerging flavivirus associated with neurological disorders, has spread rapidly to more than 70 countries and territories. However, no specific vaccines or antiviral drugs are currently available to prevent or treat ZIKV infection. Here we report that a synthetic peptide derived from the stem region of ZIKV envelope protein, designated Z2, potently inhibits infection of ZIKV and other flaviviruses in vitro. We show that Z2 interacts with ZIKV surface protein and disrupts the integrity of the viral membrane. Z2 can penetrate the placental barrier to enter fetal tissues and is safe for use in pregnant mice. Intraperitoneal administration of Z2 inhibits vertical transmission of ZIKV in pregnant C57BL/6 mice and protects type I or type I/II interferon receptor-deficient mice against lethal ZIKV challenge. Thus, Z2 has potential to be further developed as an antiviral treatment against ZIKV infection in high-risk populations, particularly pregnant women. Zika virus (ZIKV) has spread rapidly in recent years and there is a need for antiviral treatments. Here, the authors develop an antiviral peptide, based on the stem region of ZIKV envelope protein, and show that it is safe in pregnant mice and inhibits ZIKV infection in pregnant mice and fetuses.
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Affiliation(s)
- Yufeng Yu
- Key Laboratory of Medical Molecular Virology of MOE/MOH, School of Basic Medical Sciences and Shanghai Public Health Clinical Center, Fudan University, Shanghai 200032, China
| | - Yong-Qiang Deng
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100101, China
| | - Peng Zou
- Key Laboratory of Medical Molecular Virology of MOE/MOH, School of Basic Medical Sciences and Shanghai Public Health Clinical Center, Fudan University, Shanghai 200032, China
| | - Qian Wang
- Key Laboratory of Medical Molecular Virology of MOE/MOH, School of Basic Medical Sciences and Shanghai Public Health Clinical Center, Fudan University, Shanghai 200032, China
| | - Yanyan Dai
- Key Laboratory of Medical Molecular Virology of MOE/MOH, School of Basic Medical Sciences and Shanghai Public Health Clinical Center, Fudan University, Shanghai 200032, China
| | - Fei Yu
- Key Laboratory of Medical Molecular Virology of MOE/MOH, School of Basic Medical Sciences and Shanghai Public Health Clinical Center, Fudan University, Shanghai 200032, China
| | - Lanying Du
- Lindsley F. Kimball Research Institute, New York Blood Center, New York, New York 10065, USA
| | - Na-Na Zhang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100101, China
| | - Min Tian
- Beijing Hospital of Traditional Chinese Medicine affiliated to Capital Medical University, Beijing 100010, China
| | - Jia-Nan Hao
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100101, China
| | - Yu Meng
- Key Laboratory of Medical Molecular Virology of MOE/MOH, School of Basic Medical Sciences and Shanghai Public Health Clinical Center, Fudan University, Shanghai 200032, China
| | - Yuan Li
- Key Laboratory of Medical Molecular Virology of MOE/MOH, School of Basic Medical Sciences and Shanghai Public Health Clinical Center, Fudan University, Shanghai 200032, China
| | - Xiaohui Zhou
- Key Laboratory of Medical Molecular Virology of MOE/MOH, School of Basic Medical Sciences and Shanghai Public Health Clinical Center, Fudan University, Shanghai 200032, China
| | - Jasper Fuk-Woo Chan
- State Key Laboratory of Emerging Infectious Diseases, Department of Microbiology, The University of Hong Kong, Hong Kong 999077, China
| | - Kwok-Yung Yuen
- State Key Laboratory of Emerging Infectious Diseases, Department of Microbiology, The University of Hong Kong, Hong Kong 999077, China
| | - Cheng-Feng Qin
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100101, China
| | - Shibo Jiang
- Key Laboratory of Medical Molecular Virology of MOE/MOH, School of Basic Medical Sciences and Shanghai Public Health Clinical Center, Fudan University, Shanghai 200032, China.,Lindsley F. Kimball Research Institute, New York Blood Center, New York, New York 10065, USA
| | - Lu Lu
- Key Laboratory of Medical Molecular Virology of MOE/MOH, School of Basic Medical Sciences and Shanghai Public Health Clinical Center, Fudan University, Shanghai 200032, China
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226
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Abuhammad A, Al-Aqtash RA, Anson BJ, Mesecar AD, Taha MO. Computational modeling of the bat HKU4 coronavirus 3CL pro inhibitors as a tool for the development of antivirals against the emerging Middle East respiratory syndrome (MERS) coronavirus. J Mol Recognit 2017; 30. [PMID: 28608547 PMCID: PMC7166879 DOI: 10.1002/jmr.2644] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2017] [Revised: 05/01/2017] [Accepted: 05/09/2017] [Indexed: 12/22/2022]
Abstract
The Middle East respiratory syndrome coronavirus (MERS‐CoV) is an emerging virus that poses a major challenge to clinical management. The 3C‐like protease (3CLpro) is essential for viral replication and thus represents a potential target for antiviral drug development. Presently, very few data are available on MERS‐CoV 3CLpro inhibition by small molecules. We conducted extensive exploration of the pharmacophoric space of a recently identified set of peptidomimetic inhibitors of the bat HKU4‐CoV 3CLpro. HKU4‐CoV 3CLpro shares high sequence identity (81%) with the MERS‐CoV enzyme and thus represents a potential surrogate model for anti‐MERS drug discovery. We used 2 well‐established methods: Quantitative structure‐activity relationship (QSAR)‐guided modeling and docking‐based comparative intermolecular contacts analysis. The established pharmacophore models highlight structural features needed for ligand recognition and revealed important binding‐pocket regions involved in 3CLpro‐ligand interactions. The best models were used as 3D queries to screen the National Cancer Institute database for novel nonpeptidomimetic 3CLpro inhibitors. The identified hits were tested for HKU4‐CoV and MERS‐CoV 3CLpro inhibition. Two hits, which share the phenylsulfonamide fragment, showed moderate inhibitory activity against the MERS‐CoV 3CLpro and represent a potential starting point for the development of novel anti‐MERS agents. To the best of our knowledge, this is the first pharmacophore modeling study supported by in vitro validation on the MERS‐CoV 3CLpro. Highlights MERS‐CoV is an emerging virus that is closely related to the bat HKU4‐CoV. 3CLpro is a potential drug target for coronavirus infection. HKU4‐CoV 3CLpro is a useful surrogate model for the identification of MERS‐CoV 3CLpro enzyme inhibitors. dbCICA is a very robust modeling method for hit identification. The phenylsulfonamide scaffold represents a potential starting point for MERS coronavirus 3CLpro inhibitors development.
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Affiliation(s)
- Areej Abuhammad
- Department of Pharmaceutical Sciences, School of Pharmacy, The University of Jordan, Amman, Jordan
| | - Rua'a A Al-Aqtash
- Department of Pharmaceutical Sciences, School of Pharmacy, The University of Jordan, Amman, Jordan
| | - Brandon J Anson
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
| | - Andrew D Mesecar
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA.,Department of Chemistry, Purdue University, West Lafayette, IN, USA.,Centers for Cancer Research & Drug Discovery, Purdue University, West Lafayette, IN, USA
| | - Mutasem O Taha
- Department of Pharmaceutical Sciences, School of Pharmacy, The University of Jordan, Amman, Jordan
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227
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Widagdo W, Okba NM, Stalin Raj V, Haagmans BL. MERS-coronavirus: From discovery to intervention. One Health 2017; 3:11-16. [PMID: 28616497 PMCID: PMC5454172 DOI: 10.1016/j.onehlt.2016.12.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 12/15/2016] [Accepted: 12/21/2016] [Indexed: 01/16/2023] Open
Abstract
Middle East respiratory syndrome coronavirus (MERS-CoV) still causes outbreaks despite public awareness and implementation of health care measures, such as rapid viral diagnosis and patient quarantine. Here we describe the current epidemiological picture of MERS-CoV, focusing on humans and animals affected by this virus and propose specific intervention strategies that would be appropriate to control MERS-CoV. One-third of MERS-CoV patients develop severe lower respiratory tract infection and succumb to a fatal outcome; these patients would require effective therapeutic antiviral therapy. Because of the lack of such intervention strategies, supportive care is the best that can be offered at the moment. Limiting viral spread from symptomatic human cases to health care workers and family members, on the other hand, could be achieved through prophylactic administration of MERS-CoV neutralizing antibodies and vaccines. To ultimately prevent spread of the virus into the human population, however, vaccination of dromedary camels - currently the only confirmed animal host for MERS-CoV - may be the best option to achieve a sustained drop in human MERS cases in time. In the end, a One Health approach combining all these different efforts is needed to tackle this zoonotic outbreak.
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Affiliation(s)
| | | | | | - Bart L. Haagmans
- Department of Viroscience, Erasmus Medical Center, Rotterdam, The Netherlands
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228
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Rabaan AA, Bazzi AM, Al-Ahmed SH, Al-Tawfiq JA. Molecular aspects of MERS-CoV. Front Med 2017; 11:365-377. [PMID: 28500431 PMCID: PMC7089120 DOI: 10.1007/s11684-017-0521-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 01/23/2017] [Indexed: 01/19/2023]
Abstract
Middle East respiratory syndrome coronavirus (MERS-CoV) is a betacoronavirus which can cause acute respiratory distress in humans and is associated with a relatively high mortality rate. Since it was first identified in a patient who died in a Jeddah hospital in 2012, the World Health Organization has been notified of 1735 laboratory-confirmed cases from 27 countries, including 628 deaths. Most cases have occurred in Saudi Arabia. MERS-CoVancestors may be found in OldWorld bats of the Vespertilionidae family. After a proposed bat to camel switching event, transmission of MERS-CoV to humans is likely to have been the result of multiple zoonotic transfers from dromedary camels. Human-to-human transmission appears to require close contact with infected persons, with outbreaks mainly occurring in hospital environments. Outbreaks have been associated with inadequate infection prevention and control implementation, resulting in recommendations on basic and more advanced infection prevention and control measures by the World Health Organization, and issuing of government guidelines based on these recommendations in affected countries including Saudi Arabia. Evolutionary changes in the virus, particularly in the viral spike protein which mediates virus-host cell contact may potentially increase transmission of this virus. Efforts are on-going to identify specific evidence-based therapies or vaccines. The broad-spectrum antiviral nitazoxanide has been shown to have in vitro activity against MERS-CoV. Synthetic peptides and candidate vaccines based on regions of the spike protein have shown promise in rodent and non-human primate models. GLS-5300, a prophylactic DNA-plasmid vaccine encoding S protein, is the first MERS-CoV vaccine to be tested in humans, while monoclonal antibody, m336 has given promising results in animal models and has potential for use in outbreak situations.
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Affiliation(s)
- Ali A Rabaan
- Molecular Diagnostic Laboratory, Johns Hopkins Aramco Healthcare, Dhahran, 31311, Saudi Arabia.
| | - Ali M Bazzi
- Microbiology Laboratory, Johns Hopkins Aramco Healthcare, Dhahran, 31311, Saudi Arabia
| | - Shamsah H Al-Ahmed
- Specialty Paediatric Medicine, Qatif Central Hospital, Qatif, 32654, Saudi Arabia
| | - Jaffar A Al-Tawfiq
- Specialty Internal Medicine, Johns Hopkins Aramco Healthcare, Dhahran, 31311, Saudi Arabia.,University School of Medicine, Indianapolis, IN, 46202, USA
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229
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Cryo-EM structures of MERS-CoV and SARS-CoV spike glycoproteins reveal the dynamic receptor binding domains. Nat Commun 2017; 8:15092. [PMID: 28393837 PMCID: PMC5394239 DOI: 10.1038/ncomms15092] [Citation(s) in RCA: 541] [Impact Index Per Article: 77.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 02/24/2017] [Indexed: 02/05/2023] Open
Abstract
The envelope spike (S) proteins of MERS-CoV and SARS-CoV determine the virus host tropism and entry into host cells, and constitute a promising target for the development of prophylactics and therapeutics. Here, we present high-resolution structures of the trimeric MERS-CoV and SARS-CoV S proteins in its pre-fusion conformation by single particle cryo-electron microscopy. The overall structures resemble that from other coronaviruses including HKU1, MHV and NL63 reported recently, with the exception of the receptor binding domain (RBD). We captured two states of the RBD with receptor binding region either buried (lying state) or exposed (standing state), demonstrating an inherently flexible RBD readily recognized by the receptor. Further sequence conservation analysis of six human-infecting coronaviruses revealed that the fusion peptide, HR1 region and the central helix are potential targets for eliciting broadly neutralizing antibodies. Host tropism and cell entry of pathogenic coronaviruses are mediated by their envelope spike (S) proteins. Here the authors present structural analyses of trimeric MERS-CoV and SARS-CoV S proteins in pre-fusion conformation, and reveal two states of the receptor binding domain that suggest new avenues for the generation of neutralizing antibodies.
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230
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Menachery VD, Graham RL, Baric RS. Jumping species-a mechanism for coronavirus persistence and survival. Curr Opin Virol 2017; 23:1-7. [PMID: 28214731 PMCID: PMC5474123 DOI: 10.1016/j.coviro.2017.01.002] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 01/01/2017] [Accepted: 01/16/2017] [Indexed: 12/20/2022]
Abstract
Zoonotic transmission of novel viruses represents a significant threat to global public health and is fueled by globalization, the loss of natural habitats, and exposure to new hosts. For coronaviruses (CoVs), broad diversity exists within bat populations and uniquely positions them to seed future emergence events. In this review, we explore the host and viral dynamics that shape these CoV populations for survival, amplification, and possible emergence in novel hosts.
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Affiliation(s)
- Vineet D Menachery
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Rachel L Graham
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Ralph S Baric
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States.
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231
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Wang Y, Tai W, Yang J, Zhao G, Sun S, Tseng CTK, Jiang S, Zhou Y, Du L, Gao J. Receptor-binding domain of MERS-CoV with optimal immunogen dosage and immunization interval protects human transgenic mice from MERS-CoV infection. Hum Vaccin Immunother 2017; 13:1615-1624. [PMID: 28277821 DOI: 10.1080/21645515.2017.1296994] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Middle East respiratory syndrome (MERS) continues to raise worldwide concerns due to its pandemic potential. Increased MERS cases and no licensed MERS vaccines highlight the need to develop safe and effective vaccines against MERS. We have previously demonstrated that a receptor-binding domain (RBD) fragment containing residues 377-588 of MERS-coronavirus (MERS-CoV) spike protein is a critical neutralizing domain and an important vaccine target. Nevertheless, its optimal immunogen dosage and immunization interval, key factors for human-used vaccines that induce protective immunity, have never been investigated. In this study, we optimized these criteria using a recombinant MERS-CoV RBD protein fused with Fc (S377-588-Fc) and utilized the optimal immunization schedule to evaluate the protective efficacy of RBD against MERS-CoV infection in human dipeptidyl peptidase 4 transgenic (hDPP4-Tg) mice. Compared with one dose and 2 doses at 1-, 2-, and 3-week intervals, a regimen of 2 doses of this protein separated by an interval of 4 weeks induced the strongest antibody response and neutralizing antibodies against MERS-CoV infection, and maintained at a high level during the detection period. Notably, RBD protein at the optimal dosage and interval protected hDPP4-Tg mice against lethal MERS-CoV challenge, and the protection was positively correlated with serum neutralizing antibodies. Taken together, the optimal immunogen dosage and immunization interval identified in this study will provide useful guidelines for further development of MERS-CoV RBD-based vaccines for human use.
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Affiliation(s)
- Yufei Wang
- a School of Medical Laboratory Science , Wenzhou Medical University , Wenzhou , Zhejiang , China.,b Lindsley F. Kimball Research Institute , New York Blood Center , New York , NY , USA.,c State Key Laboratory of Pathogen and Biosecurity , Beijing Institute of Microbiology and Epidemiology , Beijing , China
| | - Wanbo Tai
- b Lindsley F. Kimball Research Institute , New York Blood Center , New York , NY , USA.,c State Key Laboratory of Pathogen and Biosecurity , Beijing Institute of Microbiology and Epidemiology , Beijing , China
| | - Jie Yang
- b Lindsley F. Kimball Research Institute , New York Blood Center , New York , NY , USA
| | - Guangyu Zhao
- c State Key Laboratory of Pathogen and Biosecurity , Beijing Institute of Microbiology and Epidemiology , Beijing , China
| | - Shihui Sun
- c State Key Laboratory of Pathogen and Biosecurity , Beijing Institute of Microbiology and Epidemiology , Beijing , China
| | - Chien-Te K Tseng
- d Department of Microbiology and Immunology and Center for Biodefense and Emerging Disease , University of Texas Medical Branch , Galveston , TX , USA
| | - Shibo Jiang
- b Lindsley F. Kimball Research Institute , New York Blood Center , New York , NY , USA.,e Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Basic Medical College and Institute of Medical Microbiology , Fudan University , Shanghai , China
| | - Yusen Zhou
- a School of Medical Laboratory Science , Wenzhou Medical University , Wenzhou , Zhejiang , China.,c State Key Laboratory of Pathogen and Biosecurity , Beijing Institute of Microbiology and Epidemiology , Beijing , China
| | - Lanying Du
- b Lindsley F. Kimball Research Institute , New York Blood Center , New York , NY , USA
| | - Jimin Gao
- a School of Medical Laboratory Science , Wenzhou Medical University , Wenzhou , Zhejiang , China
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232
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Chan JFW, Sridhar S, Yip CCY, Lau SKP, Woo PCY. The role of laboratory diagnostics in emerging viral infections: the example of the Middle East respiratory syndrome epidemic. J Microbiol 2017; 55:172-182. [PMID: 28243939 PMCID: PMC7090747 DOI: 10.1007/s12275-017-7026-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 02/09/2017] [Indexed: 02/07/2023]
Abstract
Rapidly emerging infectious disease outbreaks place a great strain on laboratories to develop and implement sensitive and specific diagnostic tests for patient management and infection control in a timely manner. Furthermore, laboratories also play a role in real-time zoonotic, environmental, and epidemiological investigations to identify the ultimate source of the epidemic, facilitating measures to eventually control the outbreak. Each assay modality has unique pros and cons; therefore, incorporation of a battery of tests using traditional culture-based, molecular and serological diagnostics into diagnostic algorithms is often required. As such, laboratories face challenges in assay development, test evaluation, and subsequent quality assurance. In this review, we describe the different testing modalities available for the ongoing Middle East respiratory syndrome (MERS) epidemic including cell culture, nucleic acid amplification, antigen detection, and antibody detection assays. Applications of such tests in both acute clinical and epidemiological investigation settings are highlighted. Using the MERS epidemic as an example, we illustrate the various challenges faced by laboratories in test development and implementation in the setting of a rapidly emerging infectious disease. Future directions in the diagnosis of MERS and other emerging infectious disease investigations are also highlighted.
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Affiliation(s)
- Jasper F W Chan
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong Special Administrative Region, Hong Kong, P. R. China
- Department of Microbiology, The University of Hong Kong, Hong Kong Special Administrative Region, Hong Kong, P. R. China
- Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong Special Administrative Region, Hong Kong, P. R. China
- Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong Special Administrative Region, Hong Kong, P. R. China
| | - Siddharth Sridhar
- Department of Microbiology, The University of Hong Kong, Hong Kong Special Administrative Region, Hong Kong, P. R. China
| | - Cyril C Y Yip
- Department of Microbiology, The University of Hong Kong, Hong Kong Special Administrative Region, Hong Kong, P. R. China
| | - Susanna K P Lau
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong Special Administrative Region, Hong Kong, P. R. China
- Department of Microbiology, The University of Hong Kong, Hong Kong Special Administrative Region, Hong Kong, P. R. China
- Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong Special Administrative Region, Hong Kong, P. R. China
- Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong Special Administrative Region, Hong Kong, P. R. China
| | - Patrick C Y Woo
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong Special Administrative Region, Hong Kong, P. R. China.
- Department of Microbiology, The University of Hong Kong, Hong Kong Special Administrative Region, Hong Kong, P. R. China.
- Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong Special Administrative Region, Hong Kong, P. R. China.
- Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong Special Administrative Region, Hong Kong, P. R. China.
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233
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Al-Tawfiq JA, Memish ZA. Update on therapeutic options for Middle East Respiratory Syndrome Coronavirus (MERS-CoV). Expert Rev Anti Infect Ther 2016; 15:269-275. [PMID: 27937060 PMCID: PMC7103731 DOI: 10.1080/14787210.2017.1271712] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
INTRODUCTION The Middle East Respiratory Syndrome Coronavirus (MERS-CoV) is an important emerging respiratory pathogen. MERS-CoV resulted in multiple hospital outbreaks within and outside the Arabian Peninsula. The disease has a high case fatality rate, with the need for a therapeutic option. Areas covered: In this review, we provide an overview of the progress in the development of therapeutic strategies for MERS. We searched PubMed, Embase, Cochrane, Scopus, and Google Scholar, using the following terms: 'MERS', 'MERS-CoV', 'Middle East respiratory syndrome' in combination with 'treatment' or 'therapy'. Expert commentary: There are multiple agents tried in vitro and in vivo. None of these agents were used in large clinical studies. Available clinical studies are limited to the use of the combination of interferon and other agents. These clinical studies are based solely on case reports and case series. There are no prospective or randomized trials. There is a need to have prospective and randomized clinical trials for the therapy of MERS-CoV. However, this strategy might be hampered by the sporadic cases outside the large hospital outbreaks.
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Affiliation(s)
- Jaffar A Al-Tawfiq
- a Specialty Internal Medicine , Johns Hopkins Aramco Healthcare , Dhahran , Kingdom of Saudi Arabia.,b Department of Medicine , Indiana University School of Medicine , Indianapolis , IN , USA
| | - Ziad A Memish
- c Department of Medicine , Ministry of Health , Riyadh , Kingdom of Saudi Arabia.,d Hubert Department of Global Health, Rollins School of Public Health , Emory University , Atlanta , GA , USA
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Abstract
The Middle East respiratory syndrome coronavirus (MERS-CoV) is a novel zoonotic pathogen. In 2012, the infectious outbreak caused by MERS-CoV in Saudi Arabia has spread to more than 1600 patients in 26 countries, resulting in over 600 deaths.Without a travel history, few clinical and radiological features can reliably differentiate MERS from SARS. But in real world, comparing with SARS, MERS presents more vaguely defined epidemiology, more severe symptoms, and higher case fatality rate. In this review, we summarize the recent findings in the field of MERS-CoV, especially its molecular virology, interspecies mechanisms, clinical features, antiviral therapies, and the further investigation into this disease. As a newly emerging virus, many questions are not fully answered, including the exact mode of transmission chain, geographical distribution, and animal origins. Furthermore, a new protocol needs to be launched to rapidly evaluate the effects of unproven antiviral drugs and vaccine to fasten the clinical application of new drugs.
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235
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Cryo-electron microscopy structures of the SARS-CoV spike glycoprotein reveal a prerequisite conformational state for receptor binding. Cell Res 2016; 27:119-129. [PMID: 28008928 PMCID: PMC5223232 DOI: 10.1038/cr.2016.152] [Citation(s) in RCA: 438] [Impact Index Per Article: 54.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 11/18/2016] [Accepted: 11/30/2016] [Indexed: 02/05/2023] Open
Abstract
The global outbreak of SARS in 2002-2003 was caused by the infection of a new human coronavirus SARS-CoV. The infection of SARS-CoV is mediated mainly through the viral surface glycoproteins, which consist of S1 and S2 subunits and form trimer spikes on the envelope of the virions. Here we report the ectodomain structures of the SARS-CoV surface spike trimer in different conformational states determined by single-particle cryo-electron microscopy. The conformation 1 determined at 4.3 Å resolution is three-fold symmetric and has all the three receptor-binding C-terminal domain 1 (CTD1s) of the S1 subunits in “down” positions. The binding of the “down” CTD1s to the SARS-CoV receptor ACE2 is not possible due to steric clashes, suggesting that the conformation 1 represents a receptor-binding inactive state. Conformations 2-4 determined at 7.3, 5.7 and 6.8 Å resolutions are all asymmetric, in which one RBD rotates away from the “down” position by different angles to an “up” position. The “up” CTD1 exposes the receptor-binding site for ACE2 engagement, suggesting that the conformations 2-4 represent a receptor-binding active state. This conformational change is also required for the binding of SARS-CoV neutralizing antibodies targeting the CTD1. This phenomenon could be extended to other betacoronaviruses utilizing CTD1 of the S1 subunit for receptor binding, which provides new insights into the intermediate states of coronavirus pre-fusion spike trimer during infection.
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236
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Du L, Yang Y, Zhou Y, Lu L, Li F, Jiang S. MERS-CoV spike protein: a key target for antivirals. Expert Opin Ther Targets 2016; 21:131-143. [PMID: 27936982 DOI: 10.1080/14728222.2017.1271415] [Citation(s) in RCA: 209] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
INTRODUCTION The continual Middle East respiratory syndrome (MERS) threat highlights the importance of developing effective antiviral therapeutics to prevent and treat MERS coronavirus (MERS-CoV) infection. A surface spike (S) protein guides MERS-CoV entry into host cells by binding to cellular receptor dipeptidyl peptidase-4 (DPP4), followed by fusion between virus and host cell membranes. MERS-CoV S protein represents a key target for developing therapeutics to block viral entry and inhibit membrane fusion. Areas covered: This review illustrates MERS-CoV S protein's structure and function, particularly S1 receptor-binding domain (RBD) and S2 heptad repeat 1 (HR1) as therapeutic targets, and summarizes current advancement on developing anti-MERS-CoV therapeutics, focusing on neutralizing monoclonal antibodies (mAbs) and antiviral peptides. Expert opinion: No anti-MERS-CoV therapeutic is approved for human use. Several S-targeting neutralizing mAbs and peptides have demonstrated efficacy against MERS-CoV infection, providing feasibility for development. Generally, human neutralizing mAbs targeting RBD are more potent than those targeting other regions of S protein. However, emergence of escape mutant viruses and mAb's limitations make it necessary for combining neutralizing mAbs recognizing different neutralizing epitopes and engineering them with improved efficacy and reduced cost. Optimization of the peptide sequences is expected to produce next-generation anti-MERS-CoV peptides with improved potency.
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Affiliation(s)
- Lanying Du
- a Laboratory of Viral Immunology , Lindsley F. Kimball Research Institute, New York Blood Center , New York , NY , USA
| | - Yang Yang
- b Department of Pharmacology , University of Minnesota Medical School , Minneapolis , MN , USA
| | - Yusen Zhou
- c State Key Laboratory of Pathogen and Biosecurity , Beijing Institute of Microbiology and Epidemiology , Beijing , China
| | - Lu Lu
- d Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Shanghai Medical College and Institute of Medical Microbiology , Fudan University , Shanghai , China
| | - Fang Li
- b Department of Pharmacology , University of Minnesota Medical School , Minneapolis , MN , USA
| | - Shibo Jiang
- a Laboratory of Viral Immunology , Lindsley F. Kimball Research Institute, New York Blood Center , New York , NY , USA.,d Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Shanghai Medical College and Institute of Medical Microbiology , Fudan University , Shanghai , China
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237
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Recombinant Receptor-Binding Domains of Multiple Middle East Respiratory Syndrome Coronaviruses (MERS-CoVs) Induce Cross-Neutralizing Antibodies against Divergent Human and Camel MERS-CoVs and Antibody Escape Mutants. J Virol 2016; 91:JVI.01651-16. [PMID: 27795425 DOI: 10.1128/jvi.01651-16] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 09/30/2016] [Indexed: 12/20/2022] Open
Abstract
Middle East respiratory syndrome coronavirus (MERS-CoV) binds to cellular receptor dipeptidyl peptidase 4 (DPP4) via the spike (S) protein receptor-binding domain (RBD). The RBD contains critical neutralizing epitopes and serves as an important vaccine target. Since RBD mutations occur in different MERS-CoV isolates and antibody escape mutants, cross-neutralization of divergent MERS-CoV strains by RBD-induced antibodies remains unknown. Here, we constructed four recombinant RBD (rRBD) proteins with single or multiple mutations detected in representative human MERS-CoV strains from the 2012, 2013, 2014, and 2015 outbreaks, respectively, and one rRBD protein with multiple changes derived from camel MERS-CoV strains. Like the RBD of prototype EMC2012 (EMC-RBD), all five RBDs maintained good antigenicity and functionality, the ability to bind RBD-specific neutralizing monoclonal antibodies (MAbs) and the DPP4 receptor, and high immunogenicity, able to elicit S-specific antibodies. They induced potent neutralizing antibodies cross-neutralizing 17 MERS pseudoviruses expressing S proteins of representative human and camel MERS-CoV strains identified during the 2012-2015 outbreaks, 5 MAb escape MERS-CoV mutants, and 2 live human MERS-CoV strains. We then constructed two RBDs mutated in multiple key residues in the receptor-binding motif (RBM) of RBD and demonstrated their strong cross-reactivity with anti-EMC-RBD antibodies. These RBD mutants with diminished DPP4 binding also led to virus attenuation, suggesting that immunoevasion after RBD immunization is accompanied by loss of viral fitness. Therefore, this study demonstrates that MERS-CoV RBD is an important vaccine target able to induce highly potent and broad-spectrum neutralizing antibodies against infection by divergent circulating human and camel MERS-CoV strains. IMPORTANCE MERS-CoV was first identified in June 2012 and has since spread in humans and camels. Mutations in its spike (S) protein receptor-binding domain (RBD), a key vaccine target, have been identified, raising concerns over the efficacy of RBD-based MERS vaccines against circulating human and camel MERS-CoV strains. Here, we constructed five vaccine candidates, designated 2012-RBD, 2013-RBD, 2014-RBD, 2015-RBD, and Camel-RBD, containing single or multiple mutations in the RBD of representative human and camel MERS-CoV strains during the 2012-2015 outbreaks. These RBD-based vaccine candidates maintained good functionality, antigenicity, and immunogenicity, and they induced strong cross-neutralizing antibodies against infection by divergent pseudotyped and live MERS-CoV strains, as well as antibody escape MERS-CoV mutants. This study provides impetus for further development of a safe, highly effective, and broad-spectrum RBD-based subunit vaccine to prevent MERS-CoV infection.
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238
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A recombinant receptor-binding domain of MERS-CoV in trimeric form protects human dipeptidyl peptidase 4 (hDPP4) transgenic mice from MERS-CoV infection. Virology 2016; 499:375-382. [PMID: 27750111 PMCID: PMC5167628 DOI: 10.1016/j.virol.2016.10.005] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 10/04/2016] [Accepted: 10/06/2016] [Indexed: 11/24/2022]
Abstract
Middle East respiratory syndrome (MERS) coronavirus (MERS-CoV) was first identified in 2012, and it continues to threaten human health worldwide. No MERS vaccines are licensed for human use, reinforcing the urgency to develop safe and efficacious vaccines to prevent MERS. MERS-CoV spike protein forms a trimer, and its receptor-binding domain (RBD) serves as a vaccine target. Nevertheless, the protective efficacy of RBD in its native trimeric form has never been evaluated. In this study, a trimeric protein, RBD-Fd, was generated by fusing RBD with foldon trimerization motif. It bound strongly to the receptor of MERS-CoV, dipeptidyl peptidase 4 (DPP4), and elicited robust RBD-specific neutralizing antibodies in mice, maintaining long-term neutralizing activity against MERS-CoV infection. RBD-Fd potently protected hDPP4 transgenic mice from lethal MERS-CoV challenge. These results suggest that MERS-CoV RBD in its trimeric form maintains native conformation and induces protective neutralizing antibodies, making it a candidate for further therapeutic development. A trimeric MERS-CoV protein (RBD-Fd) was constructed by fusing viral RBD with foldon trimerization motif. RBD-Fd bound strongly to dipeptidyl peptidase 4 (DPP4), the receptor of MERS-CoV, and RBD-specific neutralizing antibodies. RBD-Fd induced robust and long-term neutralizing antibodies, cross-neutralizing MERS pseudovirus of divergent strains. RBD-Fd potently protected hDPP4 transgenic mice from lethal MERS-CoV challenge.
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239
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Seong MW, Kim SY, Corman VM, Kim TS, Cho SI, Kim MJ, Lee SJ, Lee JS, Seo SH, Ahn JS, Yu BS, Park N, Oh MD, Park WB, Lee JY, Kim G, Joh JS, Jeong I, Kim EC, Drosten C, Park SS. Microevolution of Outbreak-Associated Middle East Respiratory Syndrome Coronavirus, South Korea, 2015. Emerg Infect Dis 2016; 22:327-30. [PMID: 26814649 PMCID: PMC4734539 DOI: 10.3201/eid2202.151700] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
During the 2015 Middle East respiratory syndrome coronavirus outbreak in South Korea, we sequenced full viral genomes of strains isolated from 4 patients early and late during infection. Patients represented at least 4 generations of transmission. We found no evidence of changes in the evolutionary rate and no reason to suspect adaptive changes in viral proteins.
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240
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Abstract
The coronavirus spike protein is a multifunctional molecular machine that mediates coronavirus entry into host cells. It first binds to a receptor on the host cell surface through its S1 subunit and then fuses viral and host membranes through its S2 subunit. Two domains in S1 from different coronaviruses recognize a variety of host receptors, leading to viral attachment. The spike protein exists in two structurally distinct conformations, prefusion and postfusion. The transition from prefusion to postfusion conformation of the spike protein must be triggered, leading to membrane fusion. This article reviews current knowledge about the structures and functions of coronavirus spike proteins, illustrating how the two S1 domains recognize different receptors and how the spike proteins are regulated to undergo conformational transitions. I further discuss the evolution of these two critical functions of coronavirus spike proteins, receptor recognition and membrane fusion, in the context of the corresponding functions from other viruses and host cells.
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Affiliation(s)
- Fang Li
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota 55455;
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241
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Zhu Y, Su S, Qin L, Wang Q, Shi L, Ma Z, Tang J, Jiang S, Lu L, Ye S, Zhang R. Rational improvement of gp41-targeting HIV-1 fusion inhibitors: an innovatively designed Ile-Asp-Leu tail with alternative conformations. Sci Rep 2016; 6:31983. [PMID: 27666394 PMCID: PMC5036048 DOI: 10.1038/srep31983] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 08/01/2016] [Indexed: 11/08/2022] Open
Abstract
Peptides derived from the C-terminal heptad repeat (CHR) of HIV gp41 have been developed as effective fusion inhibitors against HIV-1, but facing the challenges of enhancing potency and stability. Here, we report a rationally designed novel HIV-1 fusion inhibitor derived from CHR-derived peptide (Trp628~Gln653, named CP), but with an innovative Ile-Asp-Leu tail (IDL) that dramatically increased the inhibitory activity by up to 100 folds. We also determined the crystal structures of artificial fusion peptides N36- and N43-L6-CP-IDL. Although the overall structures of both fusion peptides share the canonical six-helix bundle (6-HB) configuration, their IDL tails adopt two different conformations: a one-turn helix with the N36, and a hook-like structure with the longer N43. Structural comparison showed that the hook-like IDL tail possesses a larger interaction interface with NHR than the helical one. Further molecular dynamics simulations of the two 6-HBs and isolated CP-IDL peptides suggested that hook-like form of IDL tail can be stabilized by its binding to NHR trimer. Therefore, CP-IDL has potential for further development as a new HIV fusion inhibitor, and this strategy could be widely used in developing artificial fusion inhibitors against HIV and other enveloped viruses.
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Affiliation(s)
- Yun Zhu
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Shan Su
- Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Basic Medical College and Shanghai Public Health Clinical Center, Fudan University, Shanghai, 200032, China
| | - Lili Qin
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Qian Wang
- Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Basic Medical College and Shanghai Public Health Clinical Center, Fudan University, Shanghai, 200032, China
| | - Lei Shi
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Zhenxuan Ma
- Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Basic Medical College and Shanghai Public Health Clinical Center, Fudan University, Shanghai, 200032, China
| | - Jianchao Tang
- National Center for Protein Science Shanghai, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 201210, China
| | - Shibo Jiang
- Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Basic Medical College and Shanghai Public Health Clinical Center, Fudan University, Shanghai, 200032, China
- Lindsley F. Kimball Research Institute, New York Blood Center, New York, New York 10065, USA
| | - Lu Lu
- Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Basic Medical College and Shanghai Public Health Clinical Center, Fudan University, Shanghai, 200032, China
| | - Sheng Ye
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Rongguang Zhang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- National Center for Protein Science Shanghai, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 201210, China
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242
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Abstract
Coronaviruses (CoVs) have a remarkable potential to change tropism. This is particularly illustrated over the last 15 years by the emergence of two zoonotic CoVs, the severe acute respiratory syndrome (SARS)- and Middle East respiratory syndrome (MERS)-CoV. Due to their inherent genetic variability, it is inevitable that new cross-species transmission events of these enveloped, positive-stranded RNA viruses will occur. Research into these medical and veterinary important pathogens—sparked by the SARS and MERS outbreaks—revealed important principles of inter- and intraspecies tropism changes. The primary determinant of CoV tropism is the viral spike (S) entry protein. Trimers of the S glycoproteins on the virion surface accommodate binding to a cell surface receptor and fusion of the viral and cellular membrane. Recently, high-resolution structures of two CoV S proteins have been elucidated by single-particle cryo-electron microscopy. Using this new structural insight, we review the changes in the S protein that relate to changes in virus tropism. Different concepts underlie these tropism changes at the cellular, tissue, and host species level, including the promiscuity or adaptability of S proteins to orthologous receptors, alterations in the proteolytic cleavage activation as well as changes in the S protein metastability. A thorough understanding of the key role of the S protein in CoV entry is critical to further our understanding of virus cross-species transmission and pathogenesis and for development of intervention strategies.
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243
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Mo Y, Fisher D. A review of treatment modalities for Middle East Respiratory Syndrome. J Antimicrob Chemother 2016; 71:3340-3350. [PMID: 27585965 PMCID: PMC7109760 DOI: 10.1093/jac/dkw338] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The Middle East Respiratory Syndrome coronavirus (MERS-CoV) has been a focus of international attention since its identification in 2012. Epidemiologically it is characterized by sporadic community cases, which are amplified by hospital-based outbreaks. Healthcare facilities in 27 countries from most continents have experienced imported cases, with the most significant outbreak involving 186 cases in Korea. The mortality internationally is 36% and guidance for clinical management has yet to be developed. Most facilities and healthcare providers outside of the Middle East receiving patients have no or little experience in the clinical management of MERS. When a case does occur there is likely little time for a critical appraisal of the literature and putative pharmacological options. We identified published literature on the management of both MERS-CoV and the Severe Acute Respiratory Syndrome coronavirus (SARS-CoV) through searches of PubMed and WHO and the US CDC websites up to 30 April 2016. A total of 101 publications were retrieved for critical appraisal. Most published literature on therapeutics for MERS are in vitro experiments, animal studies and case reports. Current treatment options for MERS can be categorized as: immunotherapy with virus-specific antibodies in convalescent plasma; polyclonal and monoclonal antibodies produced in vitro or in genetically modified animals; and antiviral agents. The use of any therapeutics in MERS-CoV remains investigational. The therapeutic agents with potential benefits and warranting further investigation include convalescent plasma, interferon-β/ribavirin combination therapy and lopinavir. Corticosteroids, ribavirin monotherapy and mycophenolic acid likely have toxicities that exceed potential benefits.
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Affiliation(s)
- Yin Mo
- Ministry of Health Holdings, Singapore.,Division of Infectious Diseases, University Medicine Cluster, National University Health System, Singapore
| | - Dale Fisher
- Division of Infectious Diseases, University Medicine Cluster, National University Health System, Singapore .,Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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244
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Agrawal AS, Ying T, Tao X, Garron T, Algaissi A, Wang Y, Wang L, Peng BH, Jiang S, Dimitrov DS, Tseng CTK. Passive Transfer of A Germline-like Neutralizing Human Monoclonal Antibody Protects Transgenic Mice Against Lethal Middle East Respiratory Syndrome Coronavirus Infection. Sci Rep 2016; 6:31629. [PMID: 27538452 PMCID: PMC4990914 DOI: 10.1038/srep31629] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 07/22/2016] [Indexed: 01/13/2023] Open
Abstract
Middle East Respiratory Syndrome coronavirus (MERS-CoV) has repeatedly caused outbreaks in the Arabian Peninsula. To date, no approved medical countermeasures (MCM) are available to combat MERS-CoV infections. Several neutralizing human monoclonal antibodies (mAbs), including m336, a germline-like human mAb, have been chosen as promising MCM for MERS-CoV. However, their clinical development has been hindered by the lack of a robust animal model that recapitulate the morbidity and mortality of human infections. We assessed the prophylactic and therapeutic efficacy of m336 by using well-characterized transgenic mice shown to be highly sensitive to MERS-CoV infection and disease. We found that mice treated with m336 prior to or post lethal MERS-CoV challenging were fully protected, compared to control mice which sufferered from profound weight loss and uniform death within days after infection. Taken together, these results support further development of m336 and other human monoclonal antibodies as potential therapeutics for MERS-CoV infection.
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Affiliation(s)
- Anurodh Shankar Agrawal
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Tianlei Ying
- Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Xinrong Tao
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Tania Garron
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Abdullah Algaissi
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA
- Department of Medical Laboratories Technology, College of Applied Medical Sciences, Jazan University, Jazan, Saudi Arabia
| | - Yanping Wang
- Protein Interactions Section, Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Lili Wang
- Protein Interactions Section, Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Bi-Hung Peng
- Neuroscience & Cell Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Shibo Jiang
- Department of Medical Laboratories Technology, College of Applied Medical Sciences, Jazan University, Jazan, Saudi Arabia
| | - Dimiter S. Dimitrov
- Protein Interactions Section, Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Chien-Te K. Tseng
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA
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245
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Wang Q, Wong G, Lu G, Yan J, Gao GF. MERS-CoV spike protein: Targets for vaccines and therapeutics. Antiviral Res 2016; 133:165-77. [PMID: 27468951 PMCID: PMC7113765 DOI: 10.1016/j.antiviral.2016.07.015] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 07/07/2016] [Accepted: 07/22/2016] [Indexed: 02/05/2023]
Abstract
The disease outbreak caused by Middle East respiratory syndrome coronavirus (MERS-CoV) is still ongoing in the Middle East. Over 1700 people have been infected since it was first reported in September 2012. Despite great efforts, licensed vaccines or therapeutics against MERS-CoV remain unavailable. The MERS-CoV spike (S) protein is an important viral antigen known to mediate host-receptor binding and virus entry, as well as induce robust humoral and cell-mediated responses in humans during infection. In this review, we highlight the importance of the S protein in the MERS-CoV life cycle, summarize recent advances in the development of vaccines and therapeutics based on the S protein, and discuss strategies that can be explored to develop new medical countermeasures against MERS-CoV. A licensed vaccine or therapeutic against MERS-CoV remains unavailable to date. The S protein plays a pivotal role for virus entry and thus is an ideal target for vaccine and antiviral development. DNA vaccines expressing the S protein merit further development for potential human application. nAbs and peptides targeting the S protein needs to be evaluated in NHPs before clinical trials.
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MESH Headings
- Animals
- Antibodies, Neutralizing/immunology
- Antibodies, Viral/immunology
- Antiviral Agents/pharmacology
- Antiviral Agents/therapeutic use
- Coronavirus Infections/prevention & control
- Coronavirus Infections/therapy
- Drug Discovery
- Humans
- Middle East Respiratory Syndrome Coronavirus/immunology
- Middle East Respiratory Syndrome Coronavirus/physiology
- Receptors, Virus/chemistry
- Receptors, Virus/metabolism
- Spike Glycoprotein, Coronavirus/chemistry
- Spike Glycoprotein, Coronavirus/genetics
- Spike Glycoprotein, Coronavirus/immunology
- Spike Glycoprotein, Coronavirus/metabolism
- Structure-Activity Relationship
- Vaccines, DNA/immunology
- Vaccines, Subunit/immunology
- Vaccines, Virus-Like Particle/immunology
- Viral Vaccines/immunology
- Virus Internalization
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Affiliation(s)
- Qihui Wang
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Shenzhen Key Laboratory of Pathogen and Immunity, Shenzhen Third People's Hospital, Shenzhen 518112, China.
| | - Gary Wong
- Shenzhen Key Laboratory of Pathogen and Immunity, Shenzhen Third People's Hospital, Shenzhen 518112, China; CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; CAS Center for Influenza Research and Early-warning (CASCIRE), Chinese Academy of Sciences, Beijing 100101, China
| | - Guangwen Lu
- West China Hospital Emergency Department (WCHED), State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, and Collaborative Innovation Center of Biotherapy, Chengdu, Sichuan 610041, China
| | - Jinghua Yan
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Shenzhen Key Laboratory of Pathogen and Immunity, Shenzhen Third People's Hospital, Shenzhen 518112, China; CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - George F Gao
- Shenzhen Key Laboratory of Pathogen and Immunity, Shenzhen Third People's Hospital, Shenzhen 518112, China; CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; CAS Center for Influenza Research and Early-warning (CASCIRE), Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention (China CDC), Beijing 102206, China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou 310003, China; Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China.
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246
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Identification of the Fusion Peptide-Containing Region in Betacoronavirus Spike Glycoproteins. J Virol 2016; 90:5586-5600. [PMID: 27030273 DOI: 10.1128/jvi.00015-16] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 03/23/2016] [Indexed: 12/26/2022] Open
Abstract
UNLABELLED The fusion peptides (FP) play an essential role in fusion of viral envelope with cellular membranes. The location and properties of the FPs in the spike (S) glycoproteins of different coronaviruses (CoV) have not yet been determined. Through amino acid sequence analysis of S proteins of representative CoVs, we identified a common region as a possible FP (pFP) that shares the characteristics of FPs of class I viral fusion proteins, including high Ala/Gly content, intermediate hydrophobicity, and few charged residues. To test the hypothesis that this region contains the CoV FP, we systemically mutated every residue in the pFP of Middle East respiratory syndrome betacoronavirus (MERS-CoV) and found that 11 of the 22 residues in the pFP (from G953 to L964, except for A956) were essential for S protein-mediated cell-cell fusion and virus entry. The synthetic MERS-CoV pFP core peptide (955IAGVGWTAGL964) induced extensive fusion of liposome membranes, while mutant peptide failed to induce any lipid mixing. We also selectively mutated residues in pFPs of two other β-CoVs, severe acute respiratory syndrome coronavirus (SARS-CoV) and mouse hepatitis virus (MHV). Although the amino acid sequences of these two pFPs differed significantly from that of MERS-CoV and each other, most of the pFP mutants of SARS-CoV and MHV also failed to mediate membrane fusion, suggesting that these pFPs are also the functional FPs. Thus, the FPs of 3 different lineages of β-CoVs are conserved in location within the S glycoproteins and in their functions, although their amino acid sequences have diverged significantly during CoV evolution. IMPORTANCE Within the class I viral fusion proteins of many enveloped viruses, the FP is the critical mediator of fusion of the viral envelope with host cell membranes leading to virus infection. FPs from within a virus family, like influenza viruses or human immunodeficiency viruses (HIV), tend to share high amino acid sequence identity. In this study, we determined the location and amino acid sequences of the FPs of S glycoproteins of 3 β-CoVs, MERS-CoV, SARS-CoV, and MHV, and demonstrated that they were essential for mediating cell-cell fusion and virus entry. Interestingly, in marked contrast to the FPs of influenza and HIV, the primary amino acid sequences of the FPs of β-CoVs in 3 different lineages differed significantly. Thus, during evolution the FPs of β-CoVs have diverged significantly in their primary sequences while maintaining the same essential biological functions. Our findings identify a potential new target for development of drugs against CoVs.
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247
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Cheng S, Wang Y, Zhang Z, Lv X, Gao GF, Shao Y, Ma L, Li X. Enfuvirtide-PEG conjugate: A potent HIV fusion inhibitor with improved pharmacokinetic properties. Eur J Med Chem 2016; 121:232-237. [PMID: 27240277 PMCID: PMC7115413 DOI: 10.1016/j.ejmech.2016.05.027] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 05/10/2016] [Accepted: 05/11/2016] [Indexed: 12/31/2022]
Abstract
Enfuvirtide (ENF) is a clinically used peptide drug for the treatment of HIV infections, but its poor pharmacokinetic profile (T1/2 = 1.5 h in rats) and low aqueous solubility make the therapy expensive and inconvenience. In this study, we present a simple and practical strategy to address these problems by conjugating ENF with polyethylene glycol (PEG). Site-specific attachment of a 2 kDa PEG at the N-terminus of ENF resulted in an ENF-PEG (EP) conjugate with high solubility (≥3 mg/mL) and long half-life in rats (T1/2 = 16.1 h). This conjugate showed similar antiviral activity to ENF against various primary HIV-1 isolates (EC50 = 6-91 nM). Mechanistic studies suggested the sources of the antiviral potency. The conjugate bound to a functional domain of the HIV gp41 protein in a helical conformation with high affinity (Kd = 307 nM), thereby inhibiting the gp41-mediated fusion of viral and host-cell membranes. As PEG conjugation has advanced many bioactive proteins and peptides into clinical applications, the EP conjugate described here represents a potential new treatment for HIV infections that may address the unmet medical needs associated with the current ENF therapy.
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Affiliation(s)
- Shuihong Cheng
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Chaoyang District, Beijing 100101, China; National Engineering Research Center for Carbohydrate Synthesis, Jiangxi Normal University, Nanchang 330022, China
| | - Yan Wang
- State Key Laboratory of Infection Disease Prevention and Control, National Center for AIDS/STD Control and Prevention, Chinese Center of Disease Control and Prevention, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Changping District, Beijing 102206, China
| | - Zhenxing Zhang
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Chaoyang District, Beijing 100101, China; University of Chinese Academy of Sciences, Shijingshan District, Beijing 100049, China
| | - Xun Lv
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Chaoyang District, Beijing 100101, China
| | - George F Gao
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Chaoyang District, Beijing 100101, China; Center for Influenza Research and Early-warning, Chinese Academy of Sciences (CASCIRE), Chaoyang District, Beijing 100101, China
| | - Yiming Shao
- State Key Laboratory of Infection Disease Prevention and Control, National Center for AIDS/STD Control and Prevention, Chinese Center of Disease Control and Prevention, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Changping District, Beijing 102206, China
| | - Liying Ma
- State Key Laboratory of Infection Disease Prevention and Control, National Center for AIDS/STD Control and Prevention, Chinese Center of Disease Control and Prevention, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Changping District, Beijing 102206, China.
| | - Xuebing Li
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Chaoyang District, Beijing 100101, China; National Engineering Research Center for Carbohydrate Synthesis, Jiangxi Normal University, Nanchang 330022, China; Center for Influenza Research and Early-warning, Chinese Academy of Sciences (CASCIRE), Chaoyang District, Beijing 100101, China.
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248
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Applications of Replicating-Competent Reporter-Expressing Viruses in Diagnostic and Molecular Virology. Viruses 2016; 8:v8050127. [PMID: 27164126 PMCID: PMC4885082 DOI: 10.3390/v8050127] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 03/31/2016] [Accepted: 04/29/2016] [Indexed: 12/13/2022] Open
Abstract
Commonly used tests based on wild-type viruses, such as immunostaining, cannot meet the demands for rapid detection of viral replication, high-throughput screening for antivirals, as well as for tracking viral proteins or virus transport in real time. Notably, the development of replicating-competent reporter-expressing viruses (RCREVs) has provided an excellent option to detect directly viral replication without the use of secondary labeling, which represents a significant advance in virology. This article reviews the applications of RCREVs in diagnostic and molecular virology, including rapid neutralization tests, high-throughput screening systems, identification of viral receptors and virus-host interactions, dynamics of viral infections in vitro and in vivo, vaccination approaches and others. However, there remain various challenges associated with RCREVs, including pathogenicity alterations due to the insertion of a reporter gene, instability or loss of the reporter gene expression, or attenuation of reporter signals in vivo. Despite all these limitations, RCREVs have become powerful tools for both basic and applied virology with the development of new technologies for generating RCREVs, the inventions of novel reporters and the better understanding of regulation of viral replication.
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249
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Zumla A, Chan JFW, Azhar EI, Hui DSC, Yuen KY. Coronaviruses - drug discovery and therapeutic options. Nat Rev Drug Discov 2016. [PMID: 26868298 DOI: 10.1038/nrd201537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
In humans, infections with the human coronavirus (HCoV) strains HCoV-229E, HCoV-OC43, HCoV-NL63 and HCoV-HKU1 usually result in mild, self-limiting upper respiratory tract infections, such as the common cold. By contrast, the CoVs responsible for severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS), which were discovered in Hong Kong, China, in 2003, and in Saudi Arabia in 2012, respectively, have received global attention over the past 12 years owing to their ability to cause community and health-care-associated outbreaks of severe infections in human populations. These two viruses pose major challenges to clinical management because there are no specific antiviral drugs available. In this Review, we summarize the epidemiology, virology, clinical features and current treatment strategies of SARS and MERS, and discuss the discovery and development of new virus-based and host-based therapeutic options for CoV infections.
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Affiliation(s)
- Alimuddin Zumla
- Division of Infection and Immunity, University College London, and NIHR Biomedical Research Centre, UCL Hospitals NHS Foundation Trust, 307 Euston Road, London NW1 3AD, UK
| | - Jasper F W Chan
- State Key Laboratory of Emerging Infectious Diseases, Carol Yu Centre for Infection, Research Centre of Infection and Immunology, Department of Microbiology, University Pathology Building, Queen Mary Hospital, The University of Hong Kong, 102 Pokfulam Road, Pokfulam, Hong Kong Special Administrative Region of the People's Republic of China
| | - Esam I Azhar
- Special Infectious Agents Unit, King Fahd Medical Research Centre, and Medical Laboratory Technology Department, Faculty of Applied Medical Sciences, King Abdulaziz University, P.O. Box 128442, Jeddah - 21362, Kingdom of Saudi Arabia
| | - David S C Hui
- Division of Respiratory Medicine and Stanley Ho Centre for Emerging Infectious Diseases, The Chinese University of Hong Kong, Prince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, New Territories, Hong Kong Special Administrative Region of the People's Republic of China
| | - Kwok-Yung Yuen
- State Key Laboratory of Emerging Infectious Diseases, Carol Yu Centre for Infection, Research Centre of Infection and Immunology, Department of Microbiology, University Pathology Building, Queen Mary Hospital, The University of Hong Kong, 102 Pokfulam Road, Pokfulam, Hong Kong Special Administrative Region of the People's Republic of China
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250
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Middle East respiratory syndrome coronavirus M protein suppresses type I interferon expression through the inhibition of TBK1-dependent phosphorylation of IRF3. Emerg Microbes Infect 2016; 5:e39. [PMID: 27094905 PMCID: PMC4855074 DOI: 10.1038/emi.2016.33] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 01/05/2016] [Accepted: 01/06/2016] [Indexed: 12/12/2022]
Abstract
Middle East respiratory syndrome coronavirus (MERS-CoV) infection has claimed hundreds of lives and has become a global threat since its emergence in Saudi Arabia in 2012. The ability of MERS-CoV to evade the host innate antiviral response may contribute to its severe pathogenesis. Many MERS-CoV-encoded proteins were identified to have interferon (IFN)-antagonizing properties, which correlates well with the reduced IFN levels observed in infected patients and ex vivo models. In this study, we fully characterized the IFN-antagonizing property of the MERS-CoV M protein. Expression of MERS-CoV M protein suppressed type I IFN expression in response to Sendai virus infection or poly(I:C) induction. This suppressive effect was found to be specific for the activation of IFN regulatory factor 3 (IRF3) but not nuclear factor-κB. MERS-CoV M protein interacted with TRAF3 and disrupted TRAF3–TBK1 association leading to reduced IRF3 activation. M proteins from MERS-CoV and SARS-CoV have three highly similar conserved N-terminal transmembrane domains and a C-terminal region. Using chimeric and truncation mutants, the N-terminal transmembrane domains of the MERS-CoV M protein were found to be sufficient for its inhibitory effect on IFN expression, whereas the C-terminal domain was unable to induce this suppression. Collectively, our findings suggest a common and conserved mechanism through which highly pathogenic MERS-CoV and SARS-CoV harness their M proteins to suppress type I IFN expression at the level of TBK1-dependent phosphorylation and activation of IRF3 resulting in evasion of the host innate antiviral response.
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