Complement-TLR4 interaction promotes the development of pathogenic Th17 cells from antigen-experienced autoreactive CD4+ T cells. WT mice were immunized with MOG38-50 in CFA. After 10 days, cells from draining lymph nodes were isolated and restimulated with MOG38-50 peptide for 4 days in the presence of 5% serum from WT mice treated with LPS or LPS + C5a or in the presence of recombinant cytokines or vehicle control (medium). (A) Cells were analyzed by FACS for IFN-γ and IL-17 production after intracellular staining. (B) Cells were analyzed by FACS for IL-10 and IL-17 production after intracellular staining. (C) Twenty million CD4+ T cells propagated by in vitro restimulation in the presence of LPS- or LPS/C5a-treated mouse serum were adoptively transferred into naive mice (n = 6 for each group). Clinical EAE scores were determined daily. Data are representatives of 2 independent experiments.
