Dendritic cells and anergic type I NKT cells play a crucial role in sulfatide-mediated immune regulation in experimental autoimmune encephalomyelitis

摘要

CD1d-restricted NKT cells can be divided into two groups: type I NKT cells utilize a semi-invariant TCR whereas type II express a relatively diverse set of TCRs. A major subset of type II NKT cells recognizes myelin-derived sulfatides and is selectively enriched in the central nervous system tissue during experimental autoimmune encephalomyelitis (EAE). We have shown that activation of sulfatide-reactive type II NKT cells by sulfatide prevents induction of EAE. Here we have addressed the mechanism of regulation as well as whether a single immunodominant form of synthetic sulfatide can treat ongoing chronic and relapsing EAE in SJL/J mice. We have shown that the activation of sulfatide-reactive type II NKT cells leads to a significant reduction in the frequency and effector function of PLP139-151/I-A^s–tetramer+ cells in lymphoid and CNS tissues. In addition, type I NKT cells and dendritic cells in the periphery as well as CNS-resident microglia are inactivated following sulfatide administration, and mice deficient in type I NKT cells are not protected from disease. Moreover tolerized DCs from sulfatide-treated animals can adoptively transfer protection into naive mice. Treatment of SJL/J mice with a synthetic cis-tetracosenoyl sulfatide, but not αGalCer, reverses ongoing chronic and relapsing EAE. Our data highlight a novel immune regulatory pathway involving NKT subset interactions leading to inactivation of type I NKT cells, DCs, and microglial cells in suppression of autoimmunity. Since CD1 molecules are non-polymorphic, the sulfatide-mediated immune regulatory pathway can be targeted for development of non-HLA-dependent therapeutic approaches to T cell-mediated autoimmune diseases.