School of Medical Sciences, Inflammatory Response and Infection Susceptibility Centre (iRiSC), Örebro University, Örebro, Sweden.
School of Medical Sciences, Inflammatory Response and Infection Susceptibility Centre (iRiSC), Örebro University, Örebro, Sweden.
Cytokine. 2019 Nov;123:154772. doi: 10.1016/j.cyto.2019.154772. Epub 2019 Jul 9.
The NLRP3 inflammasome, IL-1β release and pyroptosis (cell lysis) have recently been proposed to be essential for the progression of urinary tract infection (UTI) and elimination of intracellular bacterial niches. However, the effects of IL-1R antagonist (IL-1RA) on immune responses during UTI, except for its ability to disrupt IL-1β signalling, are not well understood. The aim of this study was to investigate the role of IL-1RA in UPEC colonization of bladder epithelial cells and the subsequent host inflammatory response. Human bladder epithelial cells (5637) and CRISPR/Cas9 generated NLRP3 and caspase-1 knockdown cells and IL-1RA knockout cells were stimulated with the UPEC isolate CFT073. The results showed that the UPEC virulence factor α-hemolysin is essential for IL-1RA release, and that the inflammasome-associated proteins caspase-1 and NLRP3 affect the release of IL-1RA. IL-1RA deficient cells showed a reduced adherence and invasion by CFT073 compared to wild-type cells, suggesting that IL-1RA may oppose mechanisms that protects against bacterial colonization. A targeted protein analysis of inflammation-related proteins showed that the basal expression of 23 proteins and the UPEC-induced expression of 10 proteins were significantly altered in IL-1RA deficient bladder epithelial cells compared to Cas9 control cells. This suggests that IL-1RA has a broad effect on the inflammatory response in bladder epithelial cells.
NLRP3 炎性小体、IL-1β 的释放和细胞焦亡（细胞裂解）最近被提出是尿路感染（UTI）进展和清除细胞内细菌生境所必需的。然而，除了破坏 IL-1β 信号传递的能力之外，IL-1 受体拮抗剂（IL-1RA）在 UTI 期间对免疫反应的影响还不是很清楚。本研究旨在探讨 IL-1RA 在 UPEC 膀胱上皮细胞定植和随后的宿主炎症反应中的作用。用 UPEC 分离株 CFT073 刺激人膀胱上皮细胞（5637）和 CRISPR/Cas9 产生的 NLRP3 和 caspase-1 敲低细胞和 IL-1RA 敲除细胞。结果表明，UPEC 毒力因子α-溶血素是 IL-1RA 释放所必需的，并且炎性小体相关蛋白 caspase-1 和 NLRP3 影响 IL-1RA 的释放。与野生型细胞相比，IL-1RA 缺陷细胞的 CFT073 粘附和侵袭减少，表明 IL-1RA 可能对抗保护细菌定植的机制。炎症相关蛋白的靶向蛋白分析表明，与 Cas9 对照细胞相比，IL-1RA 缺陷膀胱上皮细胞中 23 种蛋白的基础表达和 10 种蛋白的 UPEC 诱导表达均显著改变。这表明 IL-1RA 对膀胱上皮细胞的炎症反应有广泛的影响。
