Detection of γc-dependent cytokine signaling by immunocytochemical analysis of STAT5 phosphorylation in EBV-transformed B and ED-γc-7R cell lines. (A) Single xy plane confocal images of EBV-γc^wt, EBV-γc^low, EBV-γc^null, and ED-γc-7R cell lines labeled with anti-pSTAT5 antibody in the absence (column 1) or presence of IL-2 (5 nM), IL-7 (100 nM), or IL-15 (10 nM or 100 nM) (columns 2, 3, and 4, respectively). Scale bar represents 10 μm. (B) Immunofluorescence images of EBV-γc^wt, EBV-γc^low, and ED-γc-7R cell lines cells showing nuclear localization of pSTAT5 after IL-15 stimulation (100 nM). Cells labeled with DAPI (column 1), pSTAT5 (column 2), and merged images (column 3). Scale bar represents 20 μm.