Fig. 6.

Laquinimod immunomodulation in EAE is AhR-dependent. (A) MOG EAE mice were treated daily with laquinimod (25 mg/kg, n = 6 per group) or vehicle (water, n = 6 per group), and 15 d after immunization, spleen cells were removed and evaluated by FACS for expression of CD25 and Foxp3 by CD4⁺ cells. (Left) A representative dot plot from a vehicle-treated mouse, where CD4⁺CD25⁺ cells were gated, and the percentage of FoxP3⁺ cells was calculated from within that gate (Middle). The individual data from each animal demonstrates that laquinimod significantly increases the percentage of CD4⁺CD25⁺FoxP3⁺ regulatory T cells in WT and not AHR^−/− mice. Data are representative of two independent experiments. (B) The remaining spleen cells were restimulated with PPD or MOG in vitro, and after 48 h the culture supernatants were analyzed for IL-17, GM-CSF, and IFNγ release. Under some conditions, the cytokine levels were below the level of detection and are marked as “BQL.” Laquinimod treatment reduced MOG-specific GM-CSF (P < 0.04), IL-17, and IFNγ. Data are representative of two independent experiments.