Figure 3.

Neither programmed death ligand 1 (PD‐L1) nor PD‐L2 is critical for regulatory T (Treg) cell induction by CD11b⁻ CD103⁺ PD‐L1^High dendritic cells (DCs). DO11.10 CD4⁺ T cells (5 × 10⁵ cells/ml) were co‐cultured with the indicated CD11c⁺ cell subsets (5 × 10⁴ cells/ml) in the presence of ovalbumin peptide (OVAp; 10 nm) with anti‐PD‐L1 (a, b), anti‐PD‐L2 (c, d), or both anti‐PD‐L1 and anti‐PD‐L2 antibodies (e, f), and their isotype control antibodies (9 μg/ml). After 3·5 days, the cells in each well were collected and were analysed by flow cytometry. Two independent experiments were performed. (a, c, e) CD4 and Foxp3 expression on CD4⁺ CD11c⁻ cells are shown. Data are from a representative well of each sample. (b, d, f) Proportion of Foxp3⁺ cells in CD4⁺ CD11c⁻ cells [gates shown in (a), (c) and (e)] were analysed. The plot shows representative data from one experiment (n = 3). Symbols and horizontal bars indicate data from one well and mean of results from three wells, respectively. Statistical analysis was performed by two‐way analysis of variance and subsequent Tukey's honest significant difference test. Values not sharing a common letter are significantly different (P < 0·05). *P < 0·05, ***P < 0·001, n.s. (not significant): P ≥ 0·1.