The Role of Interleukin-17 on Renal Allograft Rejection and the Activation of Src/MAPK Cascade

• Main Authors: Hsian-Guey Hsieh, 謝現貴
• Other Authors: Ching-Yuang Lin
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/30022778557078117667

博士 === 國立陽明大學 === 微生物暨免疫學研究所 === 89 === Abstract The acute rejection is the major cause of graft damage in allograft renal transplantation. Looking for the parameters for prediction of acute rejection as early as possible is our intention. Previous studies had shown that expression of cytokine is associated with the severity of renal allograft rejection. In this study, first, using reverse transcriptase- polymerase chain reaction ( RT-PCR ) to investigate the serial change of cytokine mRNA expression at each time point during renal allograft rejection of kidney transplantation between Brown Norway (RTn) rat (donor) and Lewis (RTl) rat (recipient). We try to search a predictive parameter for borderline subclinical renal allograft rejection. It was found that Th1 cytokines including IFN-γ, IL-2, IL-12, IL-15 and IL-18 mRNA were expressed, Th2 cytokines such as IL-6, IL-10 and IL-13 mRNA, but not the IL-4 and IL-5 mRNA were detected. However, all these cytokine mRNA were not expressed in isograft as well as Sham operation group. However, IL-17 mRNA appeared on the allograft early on postoperative day 2, peaked on day 5 and then declined until it was almost undetectable at day 9 which was the day that most rats died. These changes of IL-17 mRNA expression corresponded to the changes of histopathology of allograft rejection according to the Banff classification. Therefore, IL-17 may serve as a clinical predictive parameter for subclinical renal allograft rejection. Renal epithelial cells (RECs) are the important targets in renal allograft rejection. The purpose of second study was to explore the signaling pathways by which human interleukin-17 (hIL-17) contributed to renal allograft rejection by inducing IL-6 and IL-8 expression in human renal epithelial cells (hRECs). Using RT-PCR, immunoprecipitation and western blot analysis, we reported that the early signaling events trigered by the hIL-17 involved tyrosyl phosphorylation and increased the levels of IL-6 and IL-8 in a dose-dependent manner. Tyrosyl phosphorylation was induced by IL-17 in 1 min and peaked in 5 min. Further, IL-17 induced the phosphorylation of src kinase and mitogen-activated protein (MAP) kinase. Using a specific src kinase inhibitor, pp2, to treat the hRECs before hIL-17 stimulation, we found that pp2 not only inhibited the phosphorylation of src kinase but also inhibited IL-6, IL-8 and MCP-1 mRNA expression, in a dose-dependent manner. These findings provide the first evidence that the mechanism of IL-17 signaling involves src/MAPK cascades activation.