マウスを用いた抗CD20抗体療法におけるFcレセプターの役割の解明

金沢大学附属病院H19年度は、CD20抗体療法によるB細胞除去において、抑制性受容体であるFcγRIIBが果たす役割について検討した。1)FcγRIIBのB細胞除去における役割FcγRIIB欠損マウスにおいて、IgG1、IgG2a/c、IgG2bクラスの抗CD20抗体は、野生型マウスと比べ末梢血、骨髄におけるB細胞除去能は変わらなかった。しかし、IgG1クラスの抗CD20抗体を高用量投与すると、脾臓でのB細胞除去能は亢進していた。さらに、いずれのクラスの抗体も末梢リンパ節におけるB細胞除去能は亢進していた。従って、FcγRIIBは抗CD20抗体によるB細胞除去において抑制的に働いていることが示唆された。2)マクロファージ上のFcγRIIBとB細胞上のFcγRIIBの機能の相違次に、マクロファージとB細胞に発現しているFcγRIIBのどちらがB細胞除去に抑制的に働いているか検討した。野生型マウスとFcγRIIB欠損マウスの脾臓からB細胞を単離し、CFSEで標識してレシピエントマウスに移入し、IgG2a/cクラスの抗CD20抗体を投与したところ、FcγRIIB欠損マウス由来B細胞は、野生型マウス由来B細胞より除去されにくかった。従って、FcγRIIB欠損マウスでB細胞除去能が亢進していたのは、マクロファージ上のFcγRIIBが欠損することにより抗体依存性組織障害機構が亢進したことによるものと考えられた。これらの結果は、抗CD20抗体療法の奏功率を改善させる際に、B細胞上のFcγRIIBではなくマクロファージ上のFcγRIIB発現を低下させた方がよい可能性を示しており、臨床に応用する上でも重要な知見と考えられる。研究課題/領域番号:18790778, 研究期間(年度):2006 – 2007出典：「マウスを用いた抗CD20抗体療法におけるFcレセプターの役割の解明」研究成果報告書　課題番号18790778（KAKEN：科学研究費助成事業データベース（国立情報学研究所））（https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-18790778/)を加工して作

ICAM-1とL-Selectinはブレオマイシン誘発肺臓炎を制御する

取得学位 : 博士（医学）, 学位授与番号 : 医博甲第1561号, 学位授与年月日 : 平成15年3月25日, 学位授与大学 : 金沢大

Eisenhart Lift of 22--Dimensional Mechanics

The Eisenhart lift is a variant of geometrization of classical mechanics with $d$ degrees of freedom in which the equations of motion are embedded into the geodesic equations of a Brinkmann-type metric defined on $(d+2)$-dimensional spacetime of Lorentzian signature. In this work, the Eisenhart lift of $2$-dimensional mechanics on curved background is studied. The corresponding $4$-dimensional metric is governed by two scalar functions which are just the conformal factor and the potential of the original dynamical system. We derive a conformal symmetry and a corresponding quadratic integral, associated with the Eisenhart lift. The energy--momentum tensor is constructed which, along with the metric, provides a solution to the Einstein equations. Uplifts of $2$-dimensional superintegrable models are discussed with a particular emphasis on the issue of hidden symmetries. It is shown that for the $2$-dimensional Darboux--Koenigs metrics, only type I can result in Eisenhart lifts which satisfy the weak energy condition. However, some physically viable metrics with hidden symmetries are presented.Comment: 20 page

Decreased levels of regulatory B cells in patients with systemic sclerosis: Association with autoantibody production and disease activity

Objective. B cell abnormalities characterized by autoantibody production and polyclonal B cell activation play an important role in the pathogenesis of SSc. IL-10 producing regulatory B (Breg) cells also play an important role in the negative immune response. We identified a human Breg cell subset that was predominantly found within the CD24hiCD27+ B cell subpopulation. However, the role of Breg cells in SSc remains unknown. The aim of this study was to investigate the clinical association of Breg cells in SSc patients. Methods. Blood IL-10 producing Breg cell levels were determined by FACS in 35 SSc patients and 30 healthy subjects. In a follow-up study, we analysed six individual dcSSc patients before and after treatment. Results. The frequency of blood Breg cells was significantly lower in SSc patients than in healthy controls (P<0.0001). Similarly, the frequency of CD24hiCD27+ B cells was significantly lower in SSc patients than in healthy controls (P<0.0001). SSc patients with decreased Breg cell levels often had interstitial lung disease (P<0.05). Furthermore, Breg cell levels correlated negatively with the titre of anti-topo I antibody (Ab) and anticentromere Ab in SSc patients. For a follow-up study, Breg cell levels in dcSSc patients after treatment were found to be significantly increased compared with those before treatment (P<0.05), accompanied by decreased disease activity. Thus, Breg cell levels were inversely correlated with disease activity of SSc. Conclusion. These results suggest that decreased Breg cell levels may contribute to the development of SSc. © The Author 2015.Embargo Period 12 month

The Innate Mononuclear Phagocyte Network Depletes B Lymphocytes through Fc Receptor–dependent Mechanisms during Anti-CD20 Antibody Immunotherapy

Anti-CD20 antibody immunotherapy effectively treats non-Hodgkin's lymphoma and autoimmune disease. However, the cellular and molecular pathways for B cell depletion remain undefined because human mechanistic studies are limited. Proposed mechanisms include antibody-, effector cell–, and complement-dependent cytotoxicity, the disruption of CD20 signaling pathways, and the induction of apoptosis. To identify the mechanisms for B cell depletion in vivo, a new mouse model for anti-CD20 immunotherapy was developed using a panel of twelve mouse anti–mouse CD20 monoclonal antibodies representing all four immunoglobulin G isotypes. Anti-CD20 antibodies rapidly depleted the vast majority of circulating and tissue B cells in an isotype-restricted manner that was completely dependent on effector cell Fc receptor expression. B cell depletion used both FcγRI- and FcγRIII-dependent pathways, whereas B cells were not eliminated in FcR common γ chain–deficient mice. Monocytes were the dominant effector cells for B cell depletion, with no demonstrable role for T or natural killer cells. Although most anti-CD20 antibodies activated complement in vitro, B cell depletion was completely effective in mice with genetic deficiencies in C3, C4, or C1q complement components. That the innate monocyte network depletes B cells through FcγR-dependent pathways during anti-CD20 immunotherapy has important clinical implications for anti-CD20 and other antibody-based therapies

Antisynthetase syndrome: Pulmonary computed tomography findings of adult patients with antibodies to aminoacyl-tRNA synthetases

AbstractObjectivesTo describe the pulmonary CT findings in patients with anti-ARS-antibody-positive interstitial lung disease (anti-ARS-ILD)MethodsThe CT findings of 64 patients with anti-ARS-ILD were retrospectively reviewed. The images were retrospectively reviewed independently by 2 chest radiologists, and the final decision on the CT findings was made by a third chest radiologist.ResultsThere were 16 male and 48 female patients, aged 54.2±13.4 years. Sixteen patients had anti Jo-1, 24 had anti-EJ, 9 had anti-PL-7, 7 had anti-PL-12, 5 had anti-KS, and 3 had anti-OJ antibodies. Overall, 63 patients (98.4%) had CT findings predominantly in the lower lobe; 61 patients (95.3%) showed peripheral opacities, and 47 patients (73.4%) showed peribronchovascular opacities. Ground-glass attenuation, consolidation, and reticulation showed similar distribution patterns. Regarding detailed CT findings, 89.1% of patients had lower volume loss, 76.6% had interlobular septal thickening, and 67.2% had thickening of bronchovascular bundles. The final radiologic diagnoses were as follows: inconsistent with usual interstitial pneumonia (UIP) in 63 patients (98.4%), which included nonspecific interstitial pneumonia (NSIP) in 35 patients (55.6%), organizing pneumonia (OP) in 4 patients (6.3%), and OP with fibrosis in 22 patients (34.9%).ConclusionsThe characteristic CT findings of patients with anti-ARS-ILD were areas of ground-glass attenuation and reticulation, predominantly distributed as lower and peribronchovascular lesions, which is compatible with NSIP. One-third of patients showed OP with fibrosis

CD19-dependent B lymphocyte signaling thresholds influence skin fibrosis and autoimmunity in the tight-skin mouse

金沢大学大学院医学系研究科血管分子科学The tight-skin (TSK/+) mouse, a genetic model for human systemic sclerosis (SSc), develops cutaneous fibrosis and autoantibodies against SSc-specific target autoantigens. Although molecular mechanisms explaining the development of fibrosis and autoimmunity in SSc patients or TSK/+ mice remain unknown, we recently demonstrated that SSc patients overexpress CD19, an important regulatory molecule expressed by B lymphocytes. B cells from CD19-deficient mice are hyporesponsive to transmembrane signals, while B cells overexpressing CD19 are hyperresponsive and generate autoantibodies. In this study, TSK/+ B cells also exhibited a hyperresponsive phenotype with decreased surface IgM expression, enhanced serum Ig production, and spontaneous autoantibody production. Moreover, CD19 tyrosine phosphorylation was constitutively augmented in TSK/+ B cells. CD19-mediated [Ca2+]i responses, Vav phosphorylation, and Lyn kinase activity were similarly enhanced. Studies of TSK/+ mice deficient in CD19 expression demonstrated that CD19 deficiency significantly decreased skin fibrosis in TSK/+ mice. Additionally, CD19 loss in TSK/+ mice upregulated surface IgM expression and completely abrogated hyper-γ-globulinemia and autoantibody production. CD19 deficiency also inhibited IL-6 production by TSK/+ B cells. Thus, chronic B cell activation resulting from augmented CD19 signaling in TSK/+ mice leads to skin sclerosis possibly through IL-6 overproduction as well as autoimmunity

Clinical association of serum interleukin 17 levels in systemic sclerosis: Is systemic sclerosis a Th17 disease?

金沢大学医薬保健研究域医学