HDACI-induced OX40L expression in HL blocks the generation of IL-10–producing Tr1 cells. CD4+ T cells were stimulated to differentiate into Tr1, as described in “Generation of IL-10–producing Tr1 cells,” in the presence of 6 × 104 Mino or L428 cells. (A) L428 cells were treated with DMSO or SNDX-275 (for 48 hours) in the presence of 1.5 μg/mL of anti-OX40L–neutralizing antibody or IgG1 control mAb. For the T-cell culture, cells were incubated with RPMI 1640 medium supplemented with 10% fetal calf serum, 2mM L-glutamine, penicillin G, and streptomycin. T cells were harvested after 8 days of culture before the intracellular level of IL-10 was measured by FACS analysis. Results from 2 representative experiments are shown in the left panel; a summary graph of 4 independent experiments is shown in the right panel. Each value is the mean (± SEM). *P < .05. (B) Results for Mino cells are shown for comparison. Results from 2 representative experiments are shown in the left panel; a summary graph of 4 independent experiments is shown in the right panel. Each value is the mean (± SEM).
