De Paepe Boel, De Keyzer Kristel, Martin Jean-Jacques, De Bleecker Jan L
Department of Neurology, Ghent University Hospital, De Pintelaan 185, 9000, Ghent, Belgium.
Acta Neuropathol. 2005 Jun;109(6):576-82. doi: 10.1007/s00401-005-0989-5. Epub 2005 Jun 4.
The idiopathic inflammatory myopathies (IIM) are a heterogeneous group of neuromuscular disorders subdivided into polymyositis (PM), sporadic inclusion body myositis (sIBM) and dermatomyositis (DM). Chemokines play an essential role in sustained inflammation associated with IIM. We studied the distribution of the alpha-chemokine receptors CXCR1, 2, 3 and their ligands interferon-gamma (IFN-gamma)-inducible T cell alpha chemoattractant (I-TAC), IFN-gamma-inducible protein of 10 kDa (IP-10), monokine induced by IFN-gamma (MIG) and growth-related oncogene (GRO) in IIM using immunohistochemistry, immunofluorescence and Western blotting. Abundant expression of IP-10 was observed on macrophages and T cells surrounding and invading non-necrotic muscle fibers in PM and sIBM and in T cells in perimysial infiltrates of DM. IP-10 was also localized to blood vessel endothelial cells in all inflammatory and normal muscle tissues. The distribution of other alpha-chemokines was variable: Only low levels of MIG and I-TAC were detected; GRO was localized to the endomysial infiltrates of some PM and sIBM samples, but not in DM. Muscle tissues were invariably CXCR1 negative, while a subset of inflammatory cells in all IIM were CXCR2 positive. Strong CXCR3 expression was observed on the majority of T cells in each IIM. We describe the differential repertoire of alpha-chemokines in IIM, and offer additional proof of the predominance of Th1-driven reactions in the immunopathogenesis of all three diagnostic subgroups. We suggest the Th1-mediated immunity in general, and the CXCR3/IP-10 interaction in particular, as potential targets for novel therapeutic intervention in IIM.
特发性炎性肌病(IIM)是一组异质性神经肌肉疾病,可细分为多发性肌炎(PM)、散发性包涵体肌炎(sIBM)和皮肌炎(DM)。趋化因子在与IIM相关的持续炎症中起重要作用。我们使用免疫组织化学、免疫荧光和蛋白质印迹法研究了α趋化因子受体CXCR1、2、3及其配体干扰素-γ(IFN-γ)诱导的T细胞α趋化因子(I-TAC)、10 kDa的IFN-γ诱导蛋白(IP-10)、IFN-γ诱导的单核因子(MIG)和生长相关癌基因(GRO)在IIM中的分布。在PM和sIBM中,围绕并侵入非坏死肌纤维的巨噬细胞和T细胞以及DM肌束膜浸润中的T细胞上观察到IP-10的大量表达。在所有炎症性和正常肌肉组织中,IP-10也定位于血管内皮细胞。其他α趋化因子的分布各不相同:仅检测到低水平的MIG和I-TAC;GRO定位于一些PM和sIBM样本的肌内膜浸润中,但在DM中未检测到。肌肉组织始终为CXCR1阴性,而所有IIM中的一部分炎症细胞为CXCR2阳性。在每个IIM中的大多数T细胞上观察到强烈的CXCR3表达。我们描述了IIM中α趋化因子的差异谱,并为所有三个诊断亚组免疫发病机制中Th1驱动反应的优势提供了额外证据。我们认为一般的Th1介导的免疫,特别是CXCR3/IP-10相互作用,是IIM新型治疗干预的潜在靶点。