Fig. 3

BKPyV-specific CD4⁺ (upper panel) and CD8⁺ (lower panel) T cells with IFN-γ production in KT recipient; patient number 8. Peripheral blood mononuclear cells were tested by intracellular cytokine staining for production of IFN-γ after stimulation with LT and VP1 antigens at diagnosis (a) and after adjustment of immunosuppression (b). These IFN-γ-producing cells were determined on the basis of their forward and side scatter plots