αβ T-cell receptors from multiple sclerosis brain lesions show MAIT cell–related features

Objectives: To characterize phenotypes of T cells that accumulated in multiple sclerosis (MS) lesions, to compare the lesional T-cell receptor (TCR) repertoire of T-cell subsets to peripheral blood, and to identify paired α and β chains from single CD8+ T cells from an index patient who we followed for 18 years. Methods: We combined immunohistochemistry, laser microdissection, and single-cell multiplex PCR to characterize T-cell subtypes and identify paired TCRα and TCRβ chains from individual brain-infiltrating T cells in frozen brain sections. The lesional and peripheral TCR repertoires were analyzed by pyrosequencing. Results: We found that a TCR Vβ1+ T-cell population that was strikingly expanded in active brain lesions at clinical onset comprises several subclones expressing distinct yet closely related Vα7.2+ α chains, including a canonical Vα7.2-Jα33 chain of mucosal-associated invariant T (MAIT) cells. Three other α chains bear striking similarities in their antigen-recognizing, hypervariable complementarity determining region 3. Longitudinal repertoire studies revealed that the TCR chains that were massively expanded in brain at onset persisted for several years in blood or CSF but subsequently disappeared except for the canonical Vα7.2+ MAIT cell and a few other TCR sequences that were still detectable in blood after 18 years. Conclusions: Our observation that a massively expanded TCR Vβ1-Jβ2.3 chain paired with distinct yet closely related canonical or atypical MAIT cell–related α chains strongly points to an antigen-driven process in early active MS brain lesions

ヒト ノ Th17 サイボウ ワ CCR2 ヨウセイ CCR5 インセイ デ アル

京都大学0048新制・論文博士博士(医学)乙第12271号論医博第1969号新制||医||971(附属図書館)UT51-2008-Q712(主査)教授 清水 章, 教授 湊 長博, 教授 生田 宏一学位規則第4条第2項該当Doctor of Medical ScienceKyoto UniversityDA

Application of immunotherapy for neurological manifestations in hypermobile Ehlers–Danlos syndrome

Ehlers–Danlos syndrome (EDS) is a heterogeneous heritable connective tissue disorder with various neurological manifestations, including chronic pain. The neurological manifestations in EDS are often regarded as being caused by the associated musculoskeletal disorders or polyneuropathy. Here, we present two patients with hypermobile EDS (hEDS), presenting with relapsing central nervous system (CNS) manifestations. Although the two patients showed relapsing signs of CNS manifestations like multiple sclerosis (MS) or neuromyelitis optica spectrum disorder (NMOSD), they were unique in that they had widespread opioid-dependent chronic pain, which is not consistent with the symptoms of MS/NMOSD. Unexpectedly, the serious pain of unknown origin was remarkably mitigated by plasmapheresis, and magnetic resonance imaging (MRI) examinations conducted for one of the patients were negative. Collectively, we speculate that hEDS may be more susceptible to ‘normal-appearing imaging, neuroimmunologically justified, autoimmune-mediated encephalomyelitis (NINJA).’ Analysis of the presented cases and an additional three patients with EDS with chronic pain indicates that treatable immune-mediated mechanisms deserve considerations for neurological symptoms observed in hEDS

Neuropilin‐1 (NRP1) expression distinguishes self‐reactive helper T cells in systemic autoimmune disease

Abstract Pathogenic T helper cells (Th cells) that respond to self‐antigen cannot be easily distinguished from beneficial Th cells. These cells can generate systemic autoimmune disease in response to widely expressed self‐antigens. In this study, we have identified neuropilin‐1 (NRP1) as a cell surface marker of self‐reactive Th cells. NRP1+ Th cells, absent in non‐regulatory T cell subsets in normal mice, appeared in models of systemic autoimmune disease and strongly correlated with disease symptoms. NRP1+ Th cells were greatly reduced in Nr4a2 cKO mice, which have reduced self‐reactive responses but showed normal responses against exogenous antigens. Transfer of NRP1+ Th cells was sufficient to initiate or accelerate systemic autoimmune disease, and targeting NRP1‐expressing Th cells therapeutically ameliorated SLE‐like autoimmune symptoms in BXSB‐Yaa mice. Peripheral NRP1+ Th cells were significantly increased in human SLE patients. Our data suggest that self‐reactive Th cells can be phenotypically distinguished within the Th cell pool. These findings offer a novel approach to identify self‐reactive Th cells and target them to treat systemic autoimmune disease

Circulating exosomes suppress the induction of regulatory T cells via let-7i in multiple sclerosis

Multiple sclerosis (MS) is a T cell-mediated autoimmune disease of the central nervous system. Foxp3⁺ regulatory T (Treg) cells are reduced in frequency and dysfunctional in patients with MS, but the underlying mechanisms of this deficiency are unclear. Here, we show that induction of human IFN-γ⁻IL⁻17A⁻Foxp3⁺CD4⁺ T cells is inhibited in the presence of circulating exosomes from patients with MS. The exosomal miRNA profile of patients with MS differs from that of healthy controls, and let-7i, which is markedly increased in patients with MS, suppresses induction of Treg cells by targeting insulin like growth factor 1 receptor (IGF1R) and transforming growth factor beta receptor 1 (TGFBR1). Consistently, the expression of IGF1R and TGFBR1 on circulating naive CD4⁺ T cells is reduced in patients with MS. Thus, our study shows that exosomal let-7i regulates MS pathogenesis by blocking the IGF1R/TGFBR1 pathway

Interleukin 6 signaling promotes anti-aquaporin 4 autoantibody production from plasmablasts in neuromyelitis optica

Neuromyelitis optica (NMO) is an inflammatory disease affecting the optic nerve and spinal cord, in which autoantibodies against aquaporin 4 (AQP4) water channel protein probably play a pathogenic role. Here we show that a B-cell subpopulation, exhibiting the CD19intCD27highCD38highCD180− phenotype, is selectively increased in the peripheral blood of NMO patients and that anti-AQP4 antibodies (AQP4-Abs) are mainly produced by these cells in the blood of these patients. These B cells showed the morphological as well as the phenotypical characteristics of plasmablasts (PB) and were further expanded during NMO relapse. We also demonstrate that interleukin 6 (IL-6), shown to be increased in NMO, enhanced the survival of PB as well as their AQP4-Ab secretion, whereas the blockade of IL-6 receptor (IL-6R) signaling by anti–IL-6R antibody reduced the survival of PB in vitro. These results indicate that the IL-6–dependent B-cell subpopulation is involved in the pathogenesis of NMO, thereby providing a therapeutic strategy for targeting IL-6R signaling

OTU/species diversity and richness in gut microbiota of HC40 and MS20 subjects.

<p>(a) Number of operational taxonomic units (OTUs) generated by clustering of 3,000 16S reads of gut microbiota samples from 40 healthy control subjects (HC40) and 20 patients with multiple sclerosis (MS20). (b) Estimated OTU numbers obtained from Chao1 extrapolation of the observed OTU numbers shown in (a). (c) Shannon index calculated from the observed OTU numbers. The vertical axes indicate the numbers of OTUs (a, b) and the Shannon index (c). Each box plot represents median, interquartile range, minimum, and maximum values.</p

UniFrac Principal Coordinate (PCoA) and UniFrac distance analyses for HC40 and MS20 subjects.

<p>(a, c) Open and closed circles indicate individual subjects from HC40 and MS20, respectively. (a) The two components of the unweighted PCoA plot explained 6.96% and 4.30% of the variance. ANOSIM statistic, <i>R</i> = 0.239, <i>P</i> ≤ 0.0009. (b) Mean unweighted UniFrac distances for HC-HC, HC-MS, and MS-MS subjects. (c) The two components of the weighted PCoA plot explained 18.44% and 9.86% of the variance. ANOSIM statistic, <i>R</i> = 0.208, <i>P</i> ≤ 0.002. (d) Mean weighted UniFrac distances for HC-HC, HC-MS, and MS-MS subjects. (b, d) Error bars represent standard deviations of the UniFrac distances between samples. *<i>P</i> ≤ 0.05.</p