Image_1_Fc engineered ACE2-Fc is a potent multifunctional agent targeting SARS-CoV2.tif (365.3 kB)

Image_1_Fc engineered ACE2-Fc is a potent multifunctional agent targeting SARS-CoV2.tif

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posted on 2023-01-10, 15:21 authored by Bruce D. Wines, Liriye Kurtovic, Halina M. Trist, Sandra Esparon, Ester Lopez, Klasina Chappin, Li-Jin Chan, Francesca L. Mordant, Wen Shi Lee, Nicholas A. Gherardin, Sheila K. Patel, Gemma E. Hartley, Phillip Pymm, James P. Cooney, James G. Beeson, Dale I. Godfrey, Louise M. Burrell, Menno C. van Zelm, Adam K. Wheatley, Amy W. Chung, Wai-Hong Tham, Kanta Subbarao, Stephen J. Kent, P. Mark Hogarth

Joining a function-enhanced Fc-portion of human IgG to the SARS-CoV-2 entry receptor ACE2 produces an antiviral decoy with strain transcending virus neutralizing activity. SARS-CoV-2 neutralization and Fc-effector functions of ACE2-Fc decoy proteins, formatted with or without the ACE2 collectrin domain, were optimized by Fc-modification. The different Fc-modifications resulted in distinct effects on neutralization and effector functions. H429Y, a point mutation outside the binding sites for FcγRs or complement caused non-covalent oligomerization of the ACE2-Fc decoy proteins, abrogated FcγR interaction and enhanced SARS-CoV-2 neutralization. Another Fc mutation, H429F did not improve virus neutralization but resulted in increased C5b-C9 fixation and transformed ACE2-Fc to a potent mediator of complement-dependent cytotoxicity (CDC) against SARS-CoV-2 spike (S) expressing cells. Furthermore, modification of the Fc-glycan enhanced cell activation via FcγRIIIa. These different immune profiles demonstrate the capacity of Fc-based agents to be engineered to optimize different mechanisms of protection for SARS-CoV-2 and potentially other viral pathogens.