Figure 6: PD-L2⁺ T. crassiceps macrophages suppress the pathogenic T cell response in spleen.

(a) Splenocytes from mice injected with either PBS or PD-L2⁺ macrophages (Tc-Mϕs) were treated with media containing vehicle control or with increasing concentrations of MOG_35–55 peptide (25 and 50 μg/ml) and proliferation was measured by 3H-thymidine incorporation. (b) Splenocytes from EAE mice injected with either PBS as a control or Taenia crassiceps-sorted macrophages were plated with media alone or on anti-mouse CD3 coated plates and proliferation was measured by ³H-thymidine incorporation. Stimulation index is the cpm for MOG or anti-CD3 concentrations divided by cpm for media alone. (c–f) Splenocytes were analyzed by flow cytometry and CD4⁺/CD44⁺ cells were gated on to identify activated CD4⁺ helper T cells (c). The CD4⁺/CD44⁺ population was examined to identify the percentage of IFN-γ⁺/T-bet⁺ cells (d), T-bet⁺ cells (E), IL-17⁺ cells (f) and CD25⁺/FoxP3⁺ cells (g). Significance was calculated using ANOVA (a) or t-test (b–f). The p value was indicated as follows: *p < 0.05, **p < 0.01, ***p < 0.001.