In summary, our data demonstrate an important role of Ag presentation in age-related susceptibility to CNS autoimmune disease. They suggest a scenario in which the phenotype of APC matures during development; while younger individuals may be widely protected from CNS autoimmune disease through an elevated frequency of myeloid-derived suppressor cells and plasmacytoid DCs preferentially promoting development of Treg cells, upregulation of MHC II, co-stimulatory molecules and proinflammatory cytokines may enable APCs
to generate CNS autoimmune disease-initiating this website T cells at a later maturation stage. Hereby, our data provide one immunological mechanism, which may explain the increased susceptibility to CNS autoimmune disease after childhood and concomitantly highlight modulation of APC function as an attractive therapeutic goal in Th1/Th17-mediated autoimmunity. C57BL/6 female mice were purchased from Charles River (Sulzfeld, Germany) and bred in our facilities. Vα2.3/Vβ8.2 (MBP Ac1–11) Tg B10.PL mice were also bred in
our facilities. MOG TCR Tg (2D2) mice were kindly provided by Thomas Korn (Technische Universität München, Munich, Germany). The animal protocol was approved by the ethics committee at the Technische Universität München, Munich, Germany (protocol approval number 55.2–1–54–2531–67–09). AZD1152-HQPA concentration Female C57BL/6 mice were injected subcutaneously with 100 μg MOG p35–55 (Auspep, Parkville, Australia) in complete Freund’s adjuvant (CFA, Sigma-Aldrich, Taufkirchen, Germany). Immediately after immunization and 48 h thereafter, mice received an i.v. injection of 200 ng pertussis toxin (PTx, Sigma-Aldrich). Mice immunized for the analysis of MHC II mRNA at various ages received this immunization regimen 7 days prior to analysis. Individual animals were observed daily and clinical scores were assessed as follows: 0 = no clinical disease, 1 = loss of tail tone only, 2 = mild monoparesis Calpain or paraparesis, 3 = severe paraparesis, 4 = paraplegia and/or quadraparesis, and 5 = moribund or death. Maturation, differentiation, and activation of leukocyte subsets was evaluated
by surface staining for CD11b, CD11c, B220, CD3, CD4, CD8, CD115, Gr-1, PDCA, Siglec-H, AF6.1, CD40, CD80, and CD86 (all BD Pharmingen, Heidelberg, Germany). Frequency of Treg cells was evaluated by staining for CD4//FoxP3 (all BD Pharmingen). Samples were acquired on a Beckman Coulter Cyan ADP FACS. For APC-independent T-cell activation in vitro, MACS-separated (negative selection for CD3) T cells from 2- or 8-week-old C57BL/6 mice were activated by plate-bound anti-CD3 and anti-CD28 at the indicated concentrations. For T-cell polarization, medium was supplemented as follows: 5 ng/mL IL-12 for Th1; 10 ng/mL IL-4 and 5 μg/mL anti-IFN-γ for Th2; 25 ng/mL IL-6, 0.5 ng/mL TGF-β, 10 ng/mL IL-1β, and 10 ng/mL TNF for Th17 differentiation.