Woltman Andrea M, DE Haij Simone, Boonstra Joke G, Gobin Sam J P, Daha Mohamed R, Kooten Cees VAN
Department of Nephrology, Leiden University Medical Center, Leiden, The Netherlands.
Department of Immunohematology and Blood Bank, Leiden University Medical Center, Leiden, The Netherlands.
J Am Soc Nephrol. 2000 Nov;11(11):2044-2055. doi: 10.1681/ASN.V11112044.
Renal allograft rejection is characterized by an influx of inflammatory cells. Interaction between infiltrating T cells and resident parenchymal cells might play an important role in the ongoing inflammatory response. The present study demonstrates that CD40L, a product of activated T cells, is locally expressed in kidneys undergoing rejection. Furthermore, during rejection, CD40 expression not only is present on most graft infiltrating cells but also is increased on resident tubular epithelial cells (TEC). To obtain more detailed insight in the consequences of T cell/TEC interaction, we analyzed the production of chemokines, including interleukin-8 (IL-8), monocyte chemoattractant protein-1 (MCP-1) and regulated upon activation, normal T cell expressed and secreted (RANTES), and the production of IL-6 by cultured human primary TEC in response to activation with CD40L in vitro. In addition, we studied the interaction with IL-17, a T-cell-specific cytokine previously demonstrated to be present during renal allograft rejection. The results, obtained by enzyme-linked immunosorbent assay, indicate that simultaneous activation of TEC with IL-17 and CD40L synergistically enhances production of IL-6 (2.1-fold higher than sum of single stimulations) and the chemokines IL-8 (15-fold) and RANTES (5.8-fold) as demonstrated by statistical analysis (P: < 0.05), whereas effects on MCP-1 (1.4-fold) are additive. Part of the synergy can be explained by increased CD40 expression on TEC upon IL-17 stimulation. The synergy is not unique for TEC, because similar responses were found with human synoviocytes and a foreskin fibroblast cell line (FS4). Stimulation of TEC with CD40L results in activation of NF-kappaB and induction of cytokine production by IL-17 and CD40L is prevented by addition of the NF-kappaB inhibitor pyrrolidine dithiocarbamate. These data suggest an important role for T cells in renal allograft rejection by acting on parenchymal cells via both soluble mediators and direct cellular contact.
肾移植排斥反应的特征是炎症细胞的浸润。浸润的T细胞与驻留实质细胞之间的相互作用可能在持续的炎症反应中起重要作用。本研究表明，活化T细胞的产物CD40L在发生排斥反应的肾脏中局部表达。此外，在排斥反应期间，CD40不仅存在于大多数移植浸润细胞上，而且在驻留肾小管上皮细胞（TEC）上也增加。为了更详细地了解T细胞/TEC相互作用的后果，我们分析了趋化因子的产生，包括白细胞介素-8（IL-8）、单核细胞趋化蛋白-1（MCP-1）和活化后正常T细胞表达和分泌的调节因子（RANTES），以及体外培养的人原代TEC在CD40L激活后IL-6的产生。此外，我们研究了与IL-17的相互作用，IL-17是一种先前已证实在肾移植排斥反应中存在的T细胞特异性细胞因子。通过酶联免疫吸附测定获得的结果表明，IL-17和CD40L同时激活TEC可协同增强IL-6的产生（比单次刺激的总和高2.1倍）以及趋化因子IL-8（15倍）和RANTES（5.8倍），统计学分析表明（P：<0.05），而对MCP-1的影响（1.4倍）是相加的。部分协同作用可以通过IL-17刺激后TEC上CD40表达的增加来解释。这种协同作用并非TEC所特有，因为在人滑膜细胞和包皮成纤维细胞系（FS4）中也发现了类似的反应。用CD40L刺激TEC会导致NF-κB活化，添加NF-κB抑制剂吡咯烷二硫代氨基甲酸盐可阻止IL-17和CD40L诱导细胞因子的产生。这些数据表明T细胞通过可溶性介质和直接细胞接触作用于实质细胞，在肾移植排斥反应中起重要作用。
