Abstract Number: PB1645
Meeting: ISTH 2020 Congress
Theme: Platelets and Megakaryocytes » Platelet Function and Interactions
Background: Recently, a direct interaction of platelets and red blood cells (RBCs) via FasL-FasR interaction was found to be important for the externalization of phosphatidylserine (PS) at the RBC membrane that attributes a direct role for RBCs to thrombin generation and thrombus formation and stabilization upon hemostasis and thrombosis.
Aims: –
Methods: Analysis of the recruitment of RBCs to activated platelets under flow conditions using blood samples from healthy volunteers.
Results: The inhibition of integrin aIIbb3 with Abciximab resulted in reduced platelet adhesion on recombinant FasR (CD95) and decreased PS exposure on the RBC membrane indicating an interaction between FasR on RBCs and integrin aIIbb3 at the platelet surface. This observation was further supported by increased externalization of CD61 at the platelet membrane in the presence of RBCs. Increased externalization of CD61 was blocked by specific anti-CD36 and anti-FasR antibodies as well as by FasR knock-out RBCs. The interaction of RBCs and platelets via aIIbb3 and FasR was not important for the recruitment of RBCs to activated platelets. In contrast, first results of dynamic adhesion and thrombus formation using a blocking CD36 antibody imply a contribution of CD36 of RBCs to be involved in the active recruitment of RBCs into the growing thrombus. Furthermore, flow chamber experiments with collagen-adherent platelets provide first evidence for a role of FasR and PS exposure of RBCs and the release of thrombospondin from platelets to be involved in the active recruitment of RBCs to activated platelets.
Conclusions: Taken together, the recruitment of RBCs to collagen-adherent platelets is an active process that is controlled by several surface proteins on the platelet and the RBC membrane including CD36 and FasR on RBCs and the release of thrombospondin from platelets. This initial mechanism might play a role in hemostasis and thrombosis.
To cite this abstract in AMA style:
Krott K, Elvers M. The Active Recruitment of Red Blood Cells to Activated Platelets via CD36 and FasR Is Crucial for Arterial Thrombus Formation [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/the-active-recruitment-of-red-blood-cells-to-activated-platelets-via-cd36-and-fasr-is-crucial-for-arterial-thrombus-formation/. Accessed September 29, 2023.« Back to ISTH 2020 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/the-active-recruitment-of-red-blood-cells-to-activated-platelets-via-cd36-and-fasr-is-crucial-for-arterial-thrombus-formation/