A Conformation-Dependent Neutralizing Monoclonal Antibody Specifically Targeting Receptor-Binding Domain in Middle East Respiratory Syndrome Coronavirus Spike Protein

ABSTRACT Prophylactic and therapeutic strategies are urgently needed to combat infections caused by the newly emerged Middle East respiratory syndrome coronavirus (MERS-CoV). Here, we have developed a neutralizing monoclonal antibody (MAb), designated Mersmab1, which potently blocks MERS-CoV entry into human cells. Biochemical assays reveal that Mersmab1 specifically binds to the receptor-binding domain (RBD) of the MERS-CoV spike protein and thereby competitively blocks the binding of the RBD to its cellular receptor, dipeptidyl peptidase 4 (DPP4). Furthermore, alanine scanning of the RBD has identified several residues at the DPP4-binding surface that serve as neutralizing epitopes for Mersmab1. These results suggest that if humanized, Mersmab1 could potentially function as a therapeutic antibody for treating and preventing MERS-CoV infections. Additionally, Mersmab1 may facilitate studies of the conformation and antigenicity of MERS-CoV RBD and thus will guide rational design of MERS-CoV subunit vaccines. IMPORTANCE MERS-CoV is spreading in the human population and causing severe respiratory diseases with over 40% fatality. No vaccine is currently available to prevent MERS-CoV infections. Here, we have produced a neutralizing monoclonal antibody with the capacity to effectively block MERS-CoV entry into permissive human cells. If humanized, this antibody may be used as a prophylactic and therapeutic agent against MERS-CoV infections. Specifically, when given to a person (e.g., a patient's family member or a health care worker) either before or after exposure to MERS-CoV, the humanized antibody may prevent or inhibit MERS-CoV infection, thereby stopping the spread of MERS-CoV in humans. This antibody can also serve as a useful tool to guide the design of effective MERS-CoV vaccines.

[1]  Yang Feng,et al.  Structure of Severe Acute Respiratory Syndrome Coronavirus Receptor-binding Domain Complexed with Neutralizing Antibody* , 2006, Journal of Biological Chemistry.

[2]  J. Peiris,et al.  Epidemiology and cause of severe acute respiratory syndrome (SARS) in Guangdong, People's Republic of China, in February, 2003 , 2003, The Lancet.

[3]  H. Nishida,et al.  Prevention of respiratory syncytial virus infections in high‐risk infantsby monoclonal antibody (palivizumab) , 2002, Pediatrics international : official journal of the Japan Pediatric Society.

[4]  Division on Earth.  Guide for the Care and Use of Laboratory Animals , 1996 .

[5]  Linqi Zhang,et al.  Structure of MERS-CoV spike receptor-binding domain complexed with human receptor DPP4 , 2013, Cell Research.

[6]  R. Brunham,et al.  Severe acute respiratory syndrome (SARS): a year in review. , 2005, Annual review of medicine.

[7]  George F. Gao,et al.  Structure of the Fusion Core and Inhibition of Fusion by a Heptad Repeat Peptide Derived from the S Protein of Middle East Respiratory Syndrome Coronavirus , 2013, Journal of Virology.

[8]  Shibo Jiang,et al.  A Critical HA1 Neutralizing Domain of H5N1 Influenza in an Optimal Conformation Induces Strong Cross-Protection , 2013, PloS one.

[9]  G. Gao,et al.  Crystal Structure of Severe Acute Respiratory Syndrome Coronavirus Spike Protein Fusion Core* , 2004, Journal of Biological Chemistry.

[10]  William C. Hwang,et al.  Structural Basis of Neutralization by a Human Anti-severe Acute Respiratory Syndrome Spike Protein Antibody, 80R* , 2006, Journal of Biological Chemistry.

[11]  Surender Khurana,et al.  Broadly neutralizing human antibody that recognizes the receptor-binding pocket of influenza virus hemagglutinin , 2011, Proceedings of the National Academy of Sciences.

[12]  J. Chan,et al.  The emerging novel Middle East respiratory syndrome coronavirus: The “knowns” and “unknowns” , 2013, Journal of the Formosan Medical Association.

[13]  J. Skehel,et al.  A Neutralizing Antibody Selected from Plasma Cells That Binds to Group 1 and Group 2 Influenza A Hemagglutinins , 2011, Science.

[14]  Udo Albus,et al.  Book Review: Guide for the Care and use of Laboratory Animals , 1998 .

[15]  John L. Sullivan,et al.  Angiotensin-converting enzyme 2 is a functional receptor for the SARS coronavirus , 2003, Nature.

[16]  P. Talbot,et al.  Identification of a Receptor-Binding Domain of the Spike Glycoprotein of Human Coronavirus HCoV-229E , 2003, Journal of Virology.

[17]  R. Baric,et al.  Crystal Structure of the Receptor-Binding Domain from Newly Emerged Middle East Respiratory Syndrome Coronavirus , 2013, Journal of Virology.

[18]  Lloyd H. Michael,et al.  The Guide for the Care and Use of Laboratory Animals. , 2016, ILAR journal.

[19]  Shibo Jiang,et al.  Receptor-Binding Domain of Severe Acute Respiratory Syndrome Coronavirus Spike Protein Contains Multiple Conformation-Dependent Epitopes that Induce Highly Potent Neutralizing Antibodies , 2005, The Journal of Immunology.

[20]  Christian Drosten,et al.  Dipeptidyl peptidase 4 is a functional receptor for the emerging human coronavirus-EMC , 2013, Nature.

[21]  Yi Shi,et al.  Molecular basis of binding between novel human coronavirus MERS-CoV and its receptor CD26 , 2013, Nature.

[22]  Fang Li.  Evidence for a Common Evolutionary Origin of Coronavirus Spike Protein Receptor-Binding Subunits , 2011, Journal of Virology.

[23]  Shibo Jiang,et al.  Receptor-binding domain of SARS-CoV spike protein induces highly potent neutralizing antibodies: implication for developing subunit vaccine , 2004, Biochemical and Biophysical Research Communications.

[24]  C. Morimoto,et al.  Bilateral Entry and Release of Middle East Respiratory Syndrome Coronavirus Induces Profound Apoptosis of Human Bronchial Epithelial Cells , 2013, Journal of Virology.

[25]  Shibo Jiang,et al.  Recombinant receptor-binding domain of SARS-CoV spike protein expressed in mammalian, insect and E. coli cells elicits potent neutralizing antibody and protective immunity , 2009, Virology.

[26]  R. Liddington,et al.  Identification and Structural Characterization of a Broadly Neutralizing Antibody Targeting a Novel Conserved Epitope on the Influenza Virus H5N1 Hemagglutinin , 2012, Journal of Virology.

[27]  Shibo Jiang,et al.  The spike protein of SARS-CoV — a target for vaccine and therapeutic development , 2009, Nature Reviews Microbiology.

[28]  S. Pyati,et al.  Palivizumab Use in Very Premature Infants in the Neonatal Intensive Care Unit , 2004, Pediatrics.

[29]  Boguslaw Stec,et al.  Structural and functional bases for broad-spectrum neutralization of avian and human influenza A viruses , 2009, Nature Structural &Molecular Biology.

[30]  Lu Lu,et al.  Structure-based discovery of Middle East respiratory syndrome coronavirus fusion inhibitor , 2014, Nature Communications.

[31]  Joe Lewis,et al.  Evaluation of Different Glutathione S-Transferase–Tagged Protein Captures for Screening E6/E6AP Interaction Inhibitors Using AlphaScreen® , 2007, Journal of biomolecular screening.

[32]  P. Pollack,et al.  Development and use of palivizumab (Synagis): a passive immunoprophylactic agent for RSV , 2002, Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy.

[33]  Fang Li.  Receptor recognition and cross-species infections of SARS coronavirus , 2013, Antiviral Research.

[34]  S. Harrison,et al.  Structure of SARS Coronavirus Spike Receptor-Binding Domain Complexed with Receptor , 2005, Science.

[35]  J. Berzofsky,et al.  Progress on new vaccine strategies against chronic viral infections. , 2004, The Journal of clinical investigation.

[36]  Shibo Jiang,et al.  A safe and convenient pseudovirus-based inhibition assay to detect neutralizing antibodies and screen for viral entry inhibitors against the novel human coronavirus MERS-CoV , 2013, Virology Journal.

[37]  G. Plosker,et al.  Palivizumab: a review of its use as prophylaxis for serious respiratory syncytial virus infection. , 2004, Paediatric drugs.

[38]  Clio,et al.  First cases of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) infections in France, investigations and implications for the prevention of human-to-human transmission, France, May 2013. , 2013, Euro surveillance : bulletin Europeen sur les maladies transmissibles = European communicable disease bulletin.

[39]  Shibo Jiang,et al.  A Truncated Receptor-Binding Domain of MERS-CoV Spike Protein Potently Inhibits MERS-CoV Infection and Induces Strong Neutralizing Antibody Responses: Implication for Developing Therapeutics and Vaccines , 2013, PloS one.

[40]  F. Plummer,et al.  Structural Insights into Immune Recognition of the Severe Acute Respiratory Syndrome Coronavirus S Protein Receptor Binding Domain , 2009, Journal of Molecular Biology.

[41]  John E. Shelton.  People's Republic of China , 1973 .

[42]  I. Wilson,et al.  A Unique and Conserved Neutralization Epitope in H5N1 Influenza Viruses Identified by an Antibody against the A/Goose/Guangdong/1/96 Hemagglutinin , 2013, Journal of Virology.

[43]  Xiaodong Cheng,et al.  Blocking of Exchange Proteins Directly Activated by cAMP Leads to Reduced Replication of Middle East Respiratory Syndrome Coronavirus , 2014, Journal of Virology.

[44]  A. Osterhaus,et al.  Isolation of a novel coronavirus from a man with pneumonia in Saudi Arabia. , 2012, The New England journal of medicine.

[45]  A. Debnath,et al.  Identification of a Receptor-Binding Domain in the S Protein of the Novel Human Coronavirus Middle East Respiratory Syndrome Coronavirus as an Essential Target for Vaccine Development , 2013, Journal of Virology.

[46]  S Cauchemez,et al.  Transmission scenarios for Middle East Respiratory Syndrome Coronavirus (MERS-CoV) and how to tell them apart. , 2013, Euro surveillance : bulletin Europeen sur les maladies transmissibles = European communicable disease bulletin.