Fig. 1

T cell activation led to elevated histone acetylation. a PBMCs (N = 37) were stimulated with/without PMA + I for 4 h; per-cell histone H3 (K27) acetylation (acH3) was measured by flow cytometry. Representative histograms (left) and geometric mean fluorescent intensity (gMFI) values (right) of acH3 in CD8⁺ T cells were shown. b PBMCs were treated as in (a) and then magnetically purified for CD8⁺ T cells, acH3 in cell lysates was visualized by western blot, total histone H3 served as loading control. c PBMCs (N = 13) were stimulated with/without anti-CD3 /CD28 mAbs for 4 h, acH3 was measured as in (a), shown were representative histograms (left) and summary results of gMFI (right). d Cells were treated as described in (c), and then magnetically purified for CD8⁺ T cells, expression of CD3 and acH3 were analyzed by confocal microscopy. Scale bars represent 5 μM. e PBMCs from HLA-A2⁺ individuals (N = 12) were stimulated with the CMV pp65 _(495–503) peptide in the presence of brefeldin A for 4 h; measurement of acH3 in CMV-specific (IFN-γ⁺) and non-specific (IFN-γ⁻) T cells was the same as in (a). Dot-plots of acH3 versus IFN-γ (left) and summary of acH3 gMFI (right) were shown. Experiments in (b) and (d) were repeated 5 and 3 independent times, respectively. *, p < 0.05; **, p < 0.01; ***, p < 0.001