The monoclonal antibody M.Ab.F11 recognizes junctional adhesion molecule-A (JAM-A) also known as the human platelet F11-Receptor (F11R) or JAM-1. JAM-A is a surface glycoprotein duplex (32 and 35 kDa) belongingto the immunoglobulin superfamily found on the surface of human platelets and at intercellular junctions of endothelial cells and epithelial cells. JAM-A belongs together with JAM-C (JAM-2) and JAM-B (VE-JAM or JAM-3) to a family of adhesion proteins with a V-C2 immunoglobulin domain organization. JAM-A plays an important role in tight junctions where it is involved in cell-to-cell adhesion through homophilic interactions. It co-distributes with other tight junction components such as ZO-1, 7H6 antigen, cingulin and occludin. Moreover, JAM-A plays a role in platelet aggregation, secretion, adhesion, spreading.
In the platelet, JAM-A is a membrane protein involved in 2 distinct processes initiated on the platelet surface. Namely,, antibody-induced platelet aggregation and secretion both dependent on FcgammaRII and GPIIb/IIIa integrin, a process that may be involved in pathophysiological processes associated with certain thrombocytopenias and secondly, antibody mediated platelet adhesion independent from FcgammaRII or- fibrinogen receptor that appears to play a role in physiological processes associated with platelet adhesion and aggregation. A physiological role for the JAM-A protein was demonstrated by its phosphorylation after the stimulation of platelets by thrombin and collagen. A pathophysiological role for the JAM-A was revealed by demonstrating the presence of JAM-A antibodies in patients with thrombocytopenia. Adhesion of platelets through JAM-A resulted in events characteristic of the action of cell adhesion molecules. Recent data suggests a role for JAM-A in the adhesion of platelets to cytokine-inflamed endothelial cells and thus in thrombosis and atherosclerosis induced in non-denuded blood vessels by inflammatory processes.
Flow cytometry, Functional studies, Immuno assays, Immuno fluorescence, Immuno precipitation, Paraffin sections, Western blot
FC: Antibody M.Ab. F11 stains the extracellular domain of JAM-A protein name. Cells were incubated with 5 µg/ml of mAb in 0.1%BSA/PBS. As negative control an isotype-matched antibody was used (Ref.4)
W: A non-reduced and reduced sample treatment and SDS-Page was used. The band sizes- are 32 and 35kDa (Ref. 1).
FS: Antibody M.Ab. F11 functions as anagonist resulting in platelet aggregation at concentrations of approximately 5 µg/ml (Ref.1).
For immunohistochemistry, flow cytometry and Western blotting, dilutions to be used depend on detection system applied. It is recommended that users test the reagent and determine their own optimal dilutions. The typical starting working dilution is 1:50. For functional studies, dilutions have to be optimized in user's experimental setting.