Platelet CD40L mediates thrombotic and inflammatory processes in atherosclerosis
Dirk Lievens1, Alma Zernecke, Tom Seijkens
1Department of Pathology, Maastricht Center for Atherosclerosis Research, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands.
Blood
|August 14, 2010
Summary
Platelet CD40 ligand (CD40L) drives atherosclerosis by promoting inflammation and leukocyte activation. CD40L on platelets reduces regulatory T cells, accelerating disease progression.
Area of Science:
- Immunology
- Cardiovascular Biology
- Hematology
Background:
- CD40 ligand (CD40L) is a costimulatory molecule found on T cells and platelets.
- Platelet CD40L's role in atherosclerosis, particularly its inflammatory contributions, requires further investigation.
Purpose of the Study:
- To investigate the thrombotic and inflammatory roles of platelet CD40L in atherosclerosis.
- To determine if platelet CD40L influences leukocyte adhesion, platelet-leukocyte aggregates, and regulatory T cell populations in atherosclerosis models.
Main Methods:
- Utilized CD40L-deficient (Cd40l(-/-)) and wild-type (Cd40l(+/+)) platelets in Apoe(-/-) mouse models of atherosclerosis.
- Administered activated platelets via repeated injections and assessed platelet aggregation, thrombus stability, leukocyte adhesion, plasma CCL2 levels, and regulatory T cell counts.
Main Results:
- Cd40l(-/-) platelets showed impaired aggregation and thrombus stability but significantly reduced inflammatory responses.
- Injection of Cd40l(-/-) platelets decreased leukocyte adhesion, plasma CCL2, and proinflammatory platelet-leukocyte aggregates.
- Platelet CD40L was essential for atherosclerosis development and mediated a reduction in regulatory T cells, which was linked to atheroprotection.
Conclusions:
- Platelet CD40L is a critical factor in atherosclerosis, impacting both platelet function and inflammatory processes.
- Platelet CD40L promotes atherosclerosis by activating leukocytes and increasing interactions between platelets, leukocytes, and endothelium.
- The reduction of regulatory T cells by platelet CD40L contributes significantly to accelerated atherosclerosis.
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