HBD-2 Binds SARS-CoV-2 RBD and Blocks Viral Entry: Strategy to Combat COVID-19

Abstract

New approaches to complement vaccination are needed to combat the spread of SARS-CoV-2 and stop COVID-19 related deaths and medical complications. Human beta defensin 2 (hBD-2) is a naturally occurring epithelial cell derived host defense peptide that has antiviral properties. Our comprehensive in-silico studies demonstrate that hBD-2 binds the site on the CoV-2-RBD that docks with the ACE2 receptor. Biophysical and biochemical assays confirm that hBD-2 indeed binds to the CoV-2-receptor binding domain (RBD) (KD ~ 300 nM), preventing it from binding to ACE2 expressing cells. Importantly, hBD-2 shows specificity by blocking CoV-2/spike pseudoviral infection, but not VSV-G mediated infection, of ACE2 expressing human cells with an IC50 of 2.4± 0.1 μM. These promising findings offer opportunities to develop hBD-2 and/or its derivatives and mimetics to safely and effectively use as novel agents to prevent SARS-CoV-2 infection.Funding Statement: LZ: Energy Center of TTU helped support JP; pilot funds from Drs. Weinberg and Buck for undergraduate student Ann Brewer. PR: We thank Dr. Jesse Bloom, Fred Hutchinson Cancer Center for kindly proving the plasmids to generate Spike pseudovirus and ACE2 expressing HEK 293T cells. PR funded by NIH/NIAID R01AI116730, R21AI144264, NIH/NCI grant R21 CA246194 and pilot funding from NORD Family Foundation. MB: Thanks to Dr. Parvesh Shrestha for help with MST experiments. MB funded by NIH/NEI R01EY029169 and by a pilot grant from the Department of Physiology and Biophysics of CWRU. AW: Studies herein supported by NIH/NCI R21CA253108, NIH/NIDCR R21DE028416 and pilot funds from the Department of Biological Sciences of the School of Dental Medicine, CWRU.Declaration of Interests: LZ, SKG, PR, MB and AW are co-inventors in using AMPs, and their derivatives, as anti-coronavirus agents, and have submitted an invention disclosure to Case Western Reserve University. S.C.B. J.M-G, J.P. and A.B. declare no competing interests.