Figure 3. Encephalitogenicity is dependent on IL-6 or IL-12 provided by APCs.

(A) Lymphocytes from naive Vα2.3/Vβ8.2 TCR Tg mice depleted of APCs were activated with anti-CD3/CD28 with IL-6, IL-12, or no cytokines for 48 hours. IL-23 was added for the last 18 hours of culture prior to transfer into B10.Pl mice (5 × 10⁶ cells/mouse). Anti-CD3/CD28 only (n = 6 mice), anti-CD3/28 with IL-23 during last 18 hours (n = 7), anti-CD3/28+IL-6 with IL-23 during last 18 hours (n = 8), and anti-CD3/28+IL-12 with IL-23 during last 18 hours (n = 8). ***P < 0.001 (Mann-Whitney U test). (B) Proliferation of these cells was determined by adding ³H-thymidine during the last 18 hours of parallel cultures. ***P < 0.001, 1-way ANOVA with Bonferroni’s multiple comparison test. (C) Splenocytes from naive Vα2.3/Vβ8.2 TCR Tg mice were activated with MBP Ac1-11 peptide for 3 days in the absence/presence of neutralizing Ab to IL-6 and/or IL-12. Cells were collected, and 10 × 10⁶ cells per mouse were adoptively transferred into naive B10.PL mice. The number of mice with clinical signs/total number of mice in each group in this representative experiment is shown as follows: Ag (9/10); Ag+anti-IL-6 (3/9); Ag+anti-IL-12 (4/8); and Ag+anti-IL-6/12 (4/9). ***P < 0.001 (Mann-Whitney U test). (D) Supernatants were analyzed by ELISA for IFN-γ, IL-17, IL-6, and GM-CSF. Data is representative of 3 experiments (mean ± SEM).