Figure 3.

Adherent platelets recruit and inflame monocytes. Adherent and/or activated platelets mainly interact with monocytic PSGL-1 via P-selectin and with monocytic Mac-1 (α_Mβ₂) via α_IIbβ₃ (and fibrinogen bridging) or GPIbα. Thereby, platelets initiate monocyte secretion of chemokines, cytokines, and procoagulatory tissue factor, upregulate and activate adhesion receptors and proteases, and induce monocyte differentiation into macrophages. Thus, platelet-monocyte interaction provides an atherogenic milieu at the vascular wall that supports plaque formation.