Gene-transferred platelets derived from ES cells for functional assay. A cDNA construct that produced a fusion protein of IL2 receptor and cytoplasmic domain of integrin β3 (Tac-β3) was transfected into ES cells, and platelets were produced. (A) Platelets from the transfected ES cells (day 15) were stimulated with AYPGFK, and the binding of Alexa Fluor 488-labeled fibrinogen was analyzed by flow cytometry (gray histogram, right panel). Results obtained with control platelets produced from ES cells transfected with pKJ2 are shown in the left panel. Open histograms represent the fibrinogen binding in the presence of EDTA. (B) Fibrinogen binding is expressed as mean fluorescence intensity. Data represent the mean ± SEM from platelets produced by 3 independently transfected ES clones.
