Figure 2. Absence of PD-L1 but not PD-L2 elicits a high pro-inflammatory environment in spleens.

Splenocytes were isolated from control and E2-implanted WT, PDL1^−/− and PD-L2^−/− mice, on Day 24 post-immunization and: A) cultured in the presence of 25 μg/ml mMOG_35-55 peptide for 48h. Culture supernatants were assayed for secreted levels of cytokines by Luminex Bead array. Data are representative of 2 independent experiments (mean ± SEM). B) Plated in a 96-well flat bottom microtiter plate and cultured with 10 μg/ml of mMOG_35-55 peptide for 72 h, the last 18 h in the presence of ³H-thymidine. Stimulation indices (S.I.) were determined by calculating the ratio of cpm from antigen-induced vs. unstimulated cultures. Equal number of cells from each mouse in a group were pooled and detection was done in pooled cells from n=3–4 mice/group from each of two separate experiments (mean ±SEM). Significant differences between the groups (*p ≤ 0.05) were determined by One-way ANOVA with one way analysis of variance and Newman-Keuls Multiple Comparison post test.