Figure 3.

The interaction between SARS-CoV-2 and free Spike protein with ACE2 receptors on the membrane of an endothelial cell. The interaction favours the virus entering the cell (e.g., platelets, leucocytes, macrophages, endothelia) as well as the cell activation by the free Spike. ACE2 can convert angiotensin II (made from 8 amino acids) into an inactive form (1–7), and can inactivate bradykinin, a major mediator of acute inflammation. The Spike-ACE2 interaction can lead to platelet aggregation, inflammation and thrombosis, as described in the text. Abbreviations and symbols: E: Endothelial cell; V: Virus; S: Spike; A: ACE2; sA: soluble ACE2; ATII: angiotensin II; At 1–7: angiotensin 1–7; B: Bradykinin. Solid line arrows: action, operation, effect; dashed line arrows: moving, conversion.