Fig. 1

The role of phosphatidylserine in immunity and blood coagulation. In the blood coagulation system, (1) PtdSer exposed on activated platelets can bind to the Tenase complex and Prothrombinase complex to promote the generation of thrombin. To form a clot at the injured site to achieve a hemostatic effect, thrombin activates downstream signaling pathways [28,29,30,31,32]. (2) PtdSer exposed on activated platelets can bridge with TAM receptors through the GAS6 ligand to promote platelet aggregation to maintain thrombosis and platelet stability [33]. (3) The thrombin generated through (1) can also bind to thrombomodulin to catalyze the production of Activated Protein C from Protein C. Subsequently, they inactivate Tenase complex and Prothrombinase complex, inhibiting blood coagulation. During this process, PROS1 support the anticoagulant activity of Activated Protein C [28,29,30,31,32]; In the immune system, (4) PtdSer exposed on the surface of apoptotic cells can be recognized and bound by PtdSer receptors, such as TIM, TAM, on the surface of phagocytes, leading to phagocytosis of apoptotic cells [19, 34, 35]. (5) The PtdSer exposed on the surface of some viruses, such as the Ebola Virus, Dengue Virus, can binds to PtdSer receptors on immune cells (i.e., TIM, TAM, etc.), allowing the virus to invade hosts [9,10,11,12,13,14,15]. (6) PtdSer exposed on tumor or cancer cells can also bind to PtdSer receptors (e.g., TIM, TAM) expressed on immune cells to trigger immunosuppressive pathways and ultimately promote immune escape [19,20,21,22]