Neuromuscular Immunopathology Research Laboratory, Department of Neurology, Baylor College of Medicine, Houston, Texas 77030-3411, USA.
J Cell Physiol. 2012 Dec;227(12):3857-75. doi: 10.1002/jcp.24100.
The mechanisms of hematogenous leukocyte trafficking at the human blood-nerve barrier (BNB) are largely unknown. Intercellular adhesion molecule-1 (ICAM-1) has been implicated in the pathogenesis of Guillain-Barré syndrome (GBS). We developed a cytokine-activated human in vitro BNB model using primary endoneurial endothelial cells. Endothelial treatment with 10 U/ml tissue necrosis factor-α and 20 U/ml interferon-γ resulted in de novo expression of pro-inflammatory chemokines CCL2, CXCL9, CXCL11, and CCL20, with increased expression of CXCL2-3, CXCL8, and CXCL10 relative to basal levels. Cytokine treatment induced/enhanced ICAM-1, E- and P-selectin, vascular cell adhesion molecule-1 and the alternatively spliced pro-adhesive fibronectin variant, fibronectin connecting segment-1 expression in a time-dependent manner, without alterations in junctional adhesion molecule-A expression. Lymphocytes and monocytes from untreated GBS patients express ICAM-1 counterligands, α(M)- and α(L)-integrin, with differential regulation of α(M) -integrin expression compared to healthy controls. Under flow conditions that mimic capillary hemodynamics in vivo, there was a >3-fold increase in total GBS patient and healthy control mononuclear leukocyte adhesion/migration at the BNB following cytokine treatment relative to the untreated state. Function neutralizing monoclonal antibodies against human α(M)-integrin (CD11b) and ICAM-1 reduced untreated GBS patient mononuclear leukocyte trafficking at the BNB by 59% and 64.2%, respectively. Monoclonal antibodies against α(L)-integrin (CD11a) and human intravenous immunoglobulin reduced total leukocyte adhesion/migration by 22.8% and 17.6%, respectively. This study demonstrates differential regulation of α(M)-integrin on circulating mononuclear cells in GBS, as well as an important role for α(M)-integrin-ICAM-1 interactions in pathogenic GBS patient leukocyte trafficking at the human BNB in vitro.
血液白细胞在人血神经屏障（BNB）中的迁移机制在很大程度上尚不清楚。细胞间黏附分子-1（ICAM-1）已被牵涉到格林-巴利综合征（GBS）的发病机制中。我们使用原代神经内膜内皮细胞开发了一种细胞因子激活的人体外 BNB 模型。内皮细胞用 10U/ml 肿瘤坏死因子-α和 20U/ml 干扰素-γ处理后，导致促炎趋化因子 CCL2、CXCL9、CXCL11 和 CCL20 的从头表达，与基础水平相比，CXCL2-3、CXCL8 和 CXCL10 的表达增加。细胞因子处理以时间依赖性方式诱导/增强 ICAM-1、E-和 P-选择素、血管细胞黏附分子-1 和替代性剪接的促黏附纤维连接蛋白变体纤维连接蛋白连接段-1 的表达，而不会改变连接黏附分子-A 的表达。未经治疗的 GBS 患者的淋巴细胞和单核细胞表达 ICAM-1 反配体 α(M)-和 α(L)-整合素，与健康对照组相比，α(M)-整合素的表达存在差异调节。在模拟体内毛细血管血液动力学的流动条件下，与未经处理的状态相比，细胞因子处理后，来自未经治疗的 GBS 患者和健康对照单核白细胞在 BNB 处的总黏附/迁移增加了 3 倍以上。针对人 α(M)-整合素（CD11b）和 ICAM-1 的功能中和单克隆抗体分别减少了未经治疗的 GBS 患者单核白细胞在 BNB 处的迁移 59%和 64.2%。针对 α(L)-整合素（CD11a）和人静脉免疫球蛋白的单克隆抗体分别减少了总白细胞黏附/迁移 22.8%和 17.6%。这项研究表明，GBS 中循环单核细胞上的 α(M)-整合素的调节存在差异，以及 α(M)-整合素-ICAM-1 相互作用在体外致病性 GBS 患者白细胞在人 BNB 中的迁移中的重要作用。
