These investigators report the development of recombinant soluble forms of the cell surface ACE-2 protein to act as a therapeutic decoy receptor. The decoys show no loss of potency with recent variants. The decoy receptors engage the viral receptor-binding domain (RBD) and are thought to outcompete cell-surface ACE2 for viral binding. The authors state the decoy is in theory, identical to the cell-surface receptor. Therefore, viral mutations which would weaken binding to the decoy would weaken binding to the cell surface receptor and reduce infectivity. The optimized ACE2 decoy triggers irreversible structural changes in the critical viral RBD S-protein. These studies show how ACE2 decoys function and support therapeutic development for emerging ACE-2-dependent coronaviruses.

https://www.science.org/doi/10.1126/sciadv.abq6527#.Y5Q-cRCuHjg.mailto