ABSTRACT
We show that SARS-CoV-2 spike protein interacts with cell surface heparan sulfate and angiotensin converting enzyme 2 (ACE2) through its Receptor Binding Domain. Docking studies suggest a putative heparin/heparan sulfate-binding site adjacent to the domain that binds to ACE2. In vitro, binding of ACE2 and heparin to spike protein ectodomains occurs independently and a ternary complex can be generated using heparin as a template. Contrary to studies with purified components, spike protein binding to heparan sulfate and ACE2 on cells occurs codependently. Unfractionated heparin, non-anticoagulant heparin, treatment with heparin lyases, and purified lung heparan sulfate potently block spike protein binding and infection by spike protein-pseudotyped virus and SARS-CoV-2 virus. These findings support a model for SARS-CoV-2 infection in which viral attachment and infection involves formation of a complex between heparan sulfate and ACE2. Manipulation of heparan sulfate or inhibition of viral adhesion by exogenous heparin may represent new therapeutic opportunities.Funding: This work was supported by RAPID grant 2031989 from the National Science Foundation and Project 3 of NIH P01 HL131474 to J.D.E.; The Alfred Benzon Foundation to T.M.C; NIH R01 AI146779 and a Massachusetts Consortium on Pathogenesis Readiness MassCPR grant to A.G.S.; DOD grant W81XWH-20-1-0270 and Fluomics/NOSI U19 AI135972 to S.K.C; a Career Award for Medical Scientists from the Burroughs Wellcome Fund to A.F.C.; Bill and Melinda Gates Foundation grant OPP1170236 to A.B.W.; COVID19 seed funding from the Huck Institutes of the Life Sciences and Penn State start-up funds to J.J.; and T32 training grants GM007753 for B.M.H. and T.C and AI007245 for J.F.; J.P. received funding from the Innovation Fund Denmark and VAR2 Pharmaceuticals.Conflict of Interest: J.D.E. is a co-founder of TEGA Therapeutics. J.D.E. and The Regents of the University of California have licensed a University invention to and have an equity interest in TEGA Therapeutics. The terms of this arrangement have been reviewed and approved by the University of California, San Diego in accordance with its conflict of interest policies. C.A.G and B.E.T are employees of TEGA Therapeutics.Ethical Approval: The collection of human tissue in this study abided by the Helsinki Principles. This work included postmortem human tissue, collected at the University Hospital, at the University of Copenhagen in Denmark. The patient provided informed consent for the tissue to be used for research purposes. All samples were completely deidentified before transfer to the researchers and this did not need specific IRB approval.
Subject(s)
COVID-19 , Ataxia TelangiectasiaABSTRACT
We show that SARS-CoV-2 spike protein interacts with cell surface heparan sulfate and angiotensin converting enzyme 2 (ACE2) through its Receptor Binding Domain. Docking studies suggest a putative heparin/heparan sulfate-binding site adjacent to the domain that binds to ACE2. In vitro, binding of ACE2 and heparin to spike protein ectodomains occurs independently and a ternary complex can be generated using heparin as a template. Contrary to studies with purified components, spike protein binding to heparan sulfate and ACE2 on cells occurs codependently. Unfractionated heparin, non-anticoagulant heparin, treatment with heparin lyases, and purified lung heparan sulfate potently block spike protein binding and infection by spike protein-pseudotyped virus and SARS-CoV-2 virus. These findings support a model for SARS-CoV-2 infection in which viral attachment and infection involves formation of a complex between heparan sulfate and ACE2. Manipulation of heparan sulfate or inhibition of viral adhesion by exogenous heparin may represent new therapeutic opportunities.