Fig. 6.

Effect of PKS21221 and bortezomib (BTZ) on T-cell proliferation. T cells were isolated from human PBMC and stimulated with anti-CD3 (1 µg per ml) and anti-CD28 (1 µg per ml) for 4 days. The gating strategy for flow cytometry is shown in Supplementary Fig. 14. a The percentage of proliferating cell % of CD4 (left) and CD8 (right) T cells in the presence of different concentrations of BTZ or PKS21221 is shown (mean ± SEM of triplicates). b The percentage of Ki67⁺ cell % of CD4 (left) and CD8 (right) T cells in the presence of different concentrations of BTZ or PKS21221 is shown (mean ± SEM of triplicates). Both agents inhibited the proliferation of T cells in a dose-dependent manner. c and d: T cells were stimulated with anti-CD3 and anti-CD28 for 4 days, followed by incubation with PKS21221 (1 µM) or BTZ (10 nM) for 24 h. Apoptosis c and viability d were assessed in proliferating and non-proliferating population of T cells. PKS21221 and BTZ induced apoptosis more significantly in proliferating cells, both in CD4 + and CD8 + T cells. Data are representative results with cells from three different healthy donors, each tested in two different independent experiments. *p < 0.05, **p < 0.01, ***p < 0.001, by t-test compared with non-treated group