Platelets

Platelets - also known as thrombocytes - are small, disc-shaped cells in the blood crucial for haemostasis (blood clotting), wound healing, and immune responses. Beyond their main role in clot formation, platelets play other roles in the immune system, contributing to inflammation, immunity, and tissue repair. Platelets are first activated through a series of events triggered by stimuli such as tissue injury or exposure to substances like collagen or von Willebrand factor (vWF) from damaged endothelium. This activation process leads to platelet shape change, secretion of granule contents, and the expression of activation markers on the platelet surface. Activated platelets express specific cell surface markers that indicate their activation status. P-selectin (CD62P) is rapidly exposed on the surface of activated platelets and mediates platelet-leukocyte interactions, contributing to immune responses and inflammation. Another activation marker is CD40 ligand (CD40L), involved in platelet-endothelial cell interactions and T cell activation. Soluble forms of these markers measured in blood also serve as indicators of platelet activation and potential immune involvement. Platelets interact with various immune cells, including neutrophils, monocytes, and lymphocytes. This interaction occurs through adhesion molecules and receptors on platelet surfaces. Platelet-monocyte complexes, for example, contribute to the recruitment of monocytes to sites of inflammation. These interactions can modulate immune responses, regulate leukocyte trafficking, and influence immune cell functions. Platelets release growth factors, such as platelet-derived growth factor (PDGF) and transforming growth factor-beta (TGF-β), which play critical roles in tissue repair and wound healing. These factors also influence immune responses and can modulate immune cell behaviour and inflammation. Some immune disorders are associated with abnormal platelet function. For example, immune thrombocytopenic purpura (ITP) involves the immune-mediated destruction of platelets, leading to reduced platelet counts and increased bleeding risk. In heparin-induced thrombocytopenia (HIT), an immune response to heparin causes platelet activation and clotting, leading to thrombosis. Several important markers are commonly used to study platelets and their functions. Some key markers frequently employed in platelet research include: 1) CD41 (Glycoprotein IIb/IIIa, Integrin αIIbβ3), part of the integrin complex αIIbβ3, which plays a crucial role in platelet aggregation and is involved in the binding of fibrinogen during clot formation; 2) CD61 (Glycoprotein IIIa, Integrin β3), another subunit of the αIIbβ3 integrin complex, which, together with CD41, forms the fibrinogen receptor, essential for platelet aggregation and clot formation; 3) CD62P (P-selectin, SELP), a cell surface molecule that becomes exposed on activated platelets and mediates platelet-leukocyte interactions in inflammation, immune responses, and thrombus formation; 4) CD63, a marker associated with platelet alpha granules, which store various bioactive molecules; 5) CD40 Ligand (CD40L, CD154), a transmembrane protein expressed on activated platelets involved in platelet-endothelial interactions, with roles in immune responses, including T cell activation; 6) CD42b (Glycoprotein Ib, GPIb), a surface receptor on platelets that binds to von Willebrand factor (vWF) and is crucial for platelet adhesion to damaged endothelium and initial clot formation; 7) CD9, a tetraspanin protein found on platelet surfaces associated with various platelet functions, including adhesion, aggregation, and granule secretion. We offer a large product range of research reagents for investigating platelets, including CD31 antibodies, CD63 antibodies, CD9 antibodies, eNOS ELISA Kits, and Thrombopoietin ELISA Kits. Explore our full platelets product range below and discover more, for less.