The potential role of scavenger receptor B type I (SR‐BI) in SARS‐CoV‐2 infection

Scavenger receptor type B I (SR‐BI), the major receptor for high‐density lipoprotein (HDL) mediates the delivery of cholesterol ester and cholesterol from HDL to the cell membrane. SR‐BI is implicated as a receptor for entry of severe acute respiratory syndrome coronavirus type 2 (SARS‐CoV‐2). SR‐BI is colocalized with the angiotensin‐converting enzyme 2 (ACE2) increasing the binding and affinity of SARS‐CoV‐2 to ACE2 with subsequent viral internalization. SR‐BI regulates lymphocyte proliferation and the release of pro‐inflammatory cytokines from activated macrophages and lymphocytes. SR‐BI is reduced during COVID‐19 due to consumption by SARS‐CoV‐2 infection. COVID‐19‐associated inflammatory changes and high angiotensin II (AngII) might be possible causes of repression of SR‐BI in SARS‐CoV‐2 infection. In conclusion, the downregulation of SR‐BI in COVID‐19 could be due to direct invasion by SARS‐CoV‐2 or through upregulation of pro‐inflammatory cytokines, inflammatory signaling pathways, and high circulating AngII. Reduction of SR‐BI in COVID‐19 look like ACE2 may provoke COVID‐19 severity through exaggeration of the immune response. Further studies are invoked to clarify the potential role of SR‐BI in the pathogenesis of COVID‐19 that could be protective rather than detrimental.