Vogel Jon D, West Gail A, Danese Silvio, De La Motte Carol, Phillips Manijeh H, Strong Scott A, Willis Joseph, Fiocchi Claudio
Division of Gastroenterology, University Hospitals of Cleveland, Case Western University School of Medicine, Cleveland, OH 44106, USA.
Gastroenterology. 2004 Jan;126(1):63-80. doi: 10.1053/j.gastro.2003.10.046.
The CD40 pathway is a key mediator of inflammation and autoimmunity. We investigated cell adhesion molecule (CAM) up-regulation and chemokine production by CD40-positive human intestinal fibroblasts (HIF) and microvascular endothelial cells (HIMEC) induced by CD40 ligand (CD40L)-positive T cells and soluble CD40L and their effect on T-cell adhesion and transmigration.
Expression of CD40, CD40L, and CAM was assessed by immunohistochemistry, confocal microscopy and flow cytometric analysis, and chemokine production using enzyme-linked immunosorbent assay. Calcein-labeled T cells were used to assay HIF adhesion and Transwell HIMEC transmigration.
Ligation of CD40-positive HIF and HIMEC by CD40L-positive T cells or soluble CD40L induced up-regulation of CAM expression as well as interleukin-8 and RANTES production. The specificity of these responses was shown by inhibition with a CD40L blocking antibody and by CD40 signaling-dependent p38 mitogen-activated protein kinase phosphorylation. On CD40 ligation, HIF increased their T-cell binding capacity and generated chemoattractants able to induce T-cell migration through HIMEC monolayers.
Activation of the CD40/CD40L system in the gut mucosa may trigger a self-sustaining loop of immune-nonimmune cell interactions leading to an antigen-independent influx of T cells that contributes to chronic inflammation.
CD40通路是炎症和自身免疫的关键介质。我们研究了由CD40配体（CD40L）阳性T细胞和可溶性CD40L诱导的CD40阳性人肠道成纤维细胞（HIF）和微血管内皮细胞（HIMEC）中细胞黏附分子（CAM）上调及趋化因子产生情况，以及它们对T细胞黏附和迁移的影响。
通过免疫组织化学、共聚焦显微镜和流式细胞术分析评估CD40、CD40L和CAM的表达，并用酶联免疫吸附测定法检测趋化因子产生情况。用钙黄绿素标记的T细胞检测HIF黏附及Transwell小室中HIMEC的迁移情况。
CD40L阳性T细胞或可溶性CD40L与CD40阳性HIF和HIMEC结合可诱导CAM表达上调以及白细胞介素-8和调节激活正常T细胞表达和分泌的因子（RANTES）产生。用CD40L阻断抗体抑制以及CD40信号依赖的p38丝裂原活化蛋白激酶磷酸化证明了这些反应的特异性。CD40结合后，HIF增加其T细胞结合能力并产生能够诱导T细胞通过HIMEC单层迁移的趋化因子。
肠道黏膜中CD40/CD40L系统的激活可能触发免疫细胞与非免疫细胞相互作用的自我维持循环，导致T细胞非抗原依赖性流入，从而促进慢性炎症。
