Targeting Scavenger Receptor Type B-1 (SR-B1) and Cholesterol Inhibits Entry of SARS-CoV-2 Pseudovirus in Cell Culture

Henrich, Stephen E.; McMahon, Kaylin M.; Palacio, Nicole; Bhalla, Pankaj; Penaloza-MacMaster, Pablo; Thaxton, C. Shad

The novel human coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged in Wuhan, China in late 2019 and has now caused a global pandemic. The disease caused by SARS-CoV-2 is known as COVID-19. To date, few treatments for COVID-19 have proven effective, and the current standard of care is primarily supportive. As a result, novel therapeutic strategies are in high demand. Viral entry into target cells is frequently sensitive to cell membrane lipid composition and membrane organization. Evidence suggests that cell entry of SARS-CoV-2 is most efficient when the target cell plasma membrane is replete with cholesterol; and recent data implicate cholesterol flux through the high-affinity receptor for cholesterol-rich high-density lipoprotein (HDL), called scavenger receptor type B-1 (SR-B1), as critical for SARS-CoV-2 entry. Here, we demonstrate that a cholesterol-poor synthetic biologic high-density lipoprotein (HDL NP) targets SR-B1 and inhibits cell entry of a SARS-CoV-2 spike protein pseudovirus. Human cells expressing SR-B1 are susceptible to SARS-CoV-2 infection, and viral entry can be inhibited by 50-80% using HDL NPs in an SR-B1-dependent manner. These results indicate that HDL NP targeting of SR-B1 is a powerful potential therapy to combat COVID-19 and other viral diseases.