1. SARS-CoV-2 receptor binding domain fusion protein efficiently neutralizes virus infection
- Author
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Or Alfi, Sharon Melamed, Gil Roi, Orit Berhani, Hagit Achdout, Tihana Lenac Rovis, Eran Zahavi, Einat B. Vitner, Abigael Eva Chaouat, Dana G. Wolf, Boaz Politi, Ofer Mandelboim, Stipan Jonjić, Inbal Kol, Tomer Israely, and Ilija Brizić
- Subjects
RNA viruses ,Coronaviruses ,Physiology ,viruses ,Biochemistry ,Cell Fusion ,Spectrum Analysis Techniques ,Immune Physiology ,Chlorocebus aethiops ,Biology (General) ,Receptor ,Pathology and laboratory medicine ,Virus Testing ,chemistry.chemical_classification ,Staining ,SARS-CoV-2 ,receptor binding domain ,fusion protein ,Immune System Proteins ,biology ,Chemistry ,Cell Staining ,Medical microbiology ,Flow Cytometry ,Cell biology ,Spectrophotometry ,Viruses ,293T cells ,Cell lines ,Female ,Cytophotometry ,Angiotensin-Converting Enzyme 2 ,Antibody ,SARS CoV 2 ,Pathogens ,Biological cultures ,BIOMEDICINA I ZDRAVSTVO. Temeljne medicinske znanosti ,hormones, hormone substitutes, and hormone antagonists ,Research Article ,Protein Binding ,Cell Binding ,Cell Physiology ,SARS coronavirus ,QH301-705.5 ,Recombinant Fusion Proteins ,Immunology ,Mice, Transgenic ,Research and Analysis Methods ,Microbiology ,Virus ,Antibodies ,Protein Domains ,Viral entry ,In vivo ,Diagnostic Medicine ,Neutralization Tests ,Virology ,Genetics ,Animals ,Humans ,Molecular Biology ,Vero Cells ,Medicine and health sciences ,Binding Sites ,Biology and life sciences ,BIOMEDICINE AND HEALTHCARE. Basic Medical Sciences ,Organisms ,Viral pathogens ,Proteins ,COVID-19 ,Cell Biology ,RC581-607 ,Fusion protein ,In vitro ,Microbial pathogens ,Immunoglobulin Fc Fragments ,HEK293 Cells ,Specimen Preparation and Treatment ,Immunoglobulin G ,biology.protein ,Parasitology ,Binding Sites, Antibody ,Immunologic diseases. Allergy ,Glycoprotein - Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the COVID-19 pandemic. Currently, as dangerous mutations emerge, there is an increased demand for specific treatments for SARS-CoV-2 infected patients. The spike glycoprotein on the virus envelope binds to the angiotensin converting enzyme 2 (ACE2) on host cells through its receptor binding domain (RBD) to mediate virus entry. Thus, blocking this interaction may inhibit viral entry and consequently stop infection. Here, we generated fusion proteins composed of the extracellular portions of ACE2 and RBD fused to the Fc portion of human IgG1 (ACE2-Ig and RBD-Ig, respectively). We demonstrate that ACE2-Ig is enzymatically active and that it can be recognized by the SARS-CoV-2 RBD, independently of its enzymatic activity. We further show that RBD-Ig efficiently inhibits in-vivo SARS-CoV-2 infection better than ACE2-Ig. Mechanistically, we show that anti-spike antibody generation, ACE2 enzymatic activity, and ACE2 surface expression were not affected by RBD-Ig. Finally, we show that RBD-Ig is more efficient than ACE2-Ig at neutralizing high virus titers. We thus propose that RBD-Ig physically blocks virus infection by binding to ACE2 and that RBD-Ig should be used for the treatment of SARS-CoV-2-infected patients., Author summary SARS-CoV-2 has caused serious socio-economic and health problems around the globe. As dangerous mutations emerge there is an increased demand for specific treatments for SARS-CoV-2 infected patients. SARS-CoV-2 infection starts via binding of SARS-CoV-2 spike protein’s receptor binding domain (RBD) to its receptor, ACE2, on host cells. To intercept this binding, we generated Ig-fusion proteins; ACE2-Ig was generated to block the RBD and RBD-Ig generated to block ACE2. We showed that the fusion proteins bind to their respective target and demonstrated both in-vitro and in-vivo that it is more efficient to inhibit SARS-CoV-2 infection by blocking ACE2 receptor with RBD-Ig. We further showed that RBD-Ig does not interfere with ACE2 activity or with its surface expression. We propose that RBD-Ig physically blocks virus infection by binding to ACE2 and thus it may be used for the treatment of SARS-CoV-2-infected patients.
- Published
- 2021