To clarify conformational differences between these two isoforms, PrP-deficient mice were immunized with brain homogenates of normal and scrapie-infected
animals. All mice generated anti-PrP antibodies. Peptide array analysis of these serum samples revealed a distinctive epitope of PrPSc consisting of QGSPGGN (PrP41–47) at the N-terminus. This study demonstrated a conformational dissimilarity at the N-terminus between PrPSc and PrPC, a finding that may provide novel information about conformational features of PrPSc. “
“Although NKT cells have been implicated in diverse immunomodulatory responses, the effector mechanisms underlying the NKT cell-mediated regulation of pathogenic T helper cells are not well understood. Here, we show that invariant NKT cells inhibited the
differentiation mTOR inhibitor of CD4+ T cells into Th17 cells both in vitro and in vivo. The number of IL-17-producing CD4+ T cells was reduced following co-culture with purified NK1.1+TCR+ cells from WT, but not from CD1d−/− or Jα18−/−, mice. Co-cultured NKT cells from either cytokine-deficient (IL-4−/−, IL-10−/−, or IFN-γ−/−) or WT mice efficiently inhibited Th17 differentiation. The contact-dependent mechanisms of NKT cell-mediated regulation of Th17 differentiation were confirmed using transwell co-culture experiments. On the contrary, the suppression of Th1 differentiation was dependent MK-1775 on IL-4 derived from the NKT cells. The in vivo regulatory capacity of NKT cells on Th17 cells was confirmed using an experimental autoimmune uveitis model induced with human IRBP1–20 (IRBP, interphotoreceptor retinoid-binding protein) peptide. NKT cell-deficient mice (CD1d−/− or Jα18−/−) demonstrated an increased disease severity, which was reversed by the transfer of WT or cytokine-deficient (IL-4−/−, IL-10−/−, or IFN-γ−/−) NKT cells. Our
results indicate that invariant NKT cells inhibited autoimmune uveitis predominantly through Oxalosuccinic acid the cytokine-independent inhibition of Th17 differentiation. The long-served Th1/Th2 hypothesis has been updated by the identification of a third subset, IL-17-producing CD4+ Th (Th17 cells) 1. Although Th1 cells mainly provide protection against intracellular microorganisms and Th2 cells protect against helminthes, Th17 cells have been implicated in the host defense against extracellular bacteria and fungi 2. Uncontrolled Th17 responses have been recently reported in autoimmune diseases such as rheumatoid arthritis, multiple sclerosis, psoriasis, and inflammatory bowel diseases in human and mouse models 1–3, which were formerly considered Th1-mediated diseases. In mice, naïve CD4+ T cells differentiate into Th17 cells in the presence of IL-6 and TGF-β 4. TGF-β is a pleiotropic cytokine with potent regulatory capacities that modulates the activation and homeostasis of effector T cells and induces Foxp3+ Tregs 5.