Fig. 1: Does protein S link blood clotting and cytokine storms in COVID-19?
From: Blood clots and TAM receptor signalling in COVID-19 pathogenesis
Infection by SARS-CoV-2 is associated with fulminant blood clotting. This weakens vessel walls, resulting in their local rupture and haemorrhage into tissues. The growing clot consumes clotting factors, including the anticoagulant protein S (PROS1), which is also a ligand for the immunosuppressive receptor tyrosine kinase (TK) MER, expressed by macrophages and other immune sentinels. PROS1 depletion may silence MER signalling and activate sentinel cells to express and secrete inflammatory cytokines. RBC, red blood cell; TNF, tumour necrosis factor.
