Agace W W, Hedges S R, Ceska M, Svanborg C
Department of Medical Microbiology, Lund University, Sweden.
J Clin Invest. 1993 Aug;92(2):780-5. doi: 10.1172/JCI116650.
Urinary tract infections activate a mucosal inflammatory response, which includes cytokine secretion and neutrophil influx. The mechanisms involved in the neutrophil influx have not been identified. Interleukin-8, a potent chemoattractant for neutrophils, is produced by urinary tract epithelial cell lines in vitro. This study analyzed the human IL-8 response to deliberate Escherichia coli infection of the urinary tract. Urine and serum samples were obtained before and after intravesical instillation of E. coli. Neutrophil numbers were determined on uncentrifuged urine, and IL-8 levels were measured by ELISA. A urinary IL-8 response was found in all patients after bacterial instillation, but no serum IL-8 was detected. There was a strong correlation between urinary IL-8 levels and urinary neutrophil numbers. The same E. coli strains used to colonize the patients stimulated IL-8 production in urinary tract epithelial cells. The level of IL-8 secreted by epithelial cell lines was influenced by the fimbrial properties of the E. coli. These results demonstrated that E. coli elicit a mucosal IL-8 response in humans, and suggested that IL-8 is involved in the onset of pyuria. Epithelial cells may be an important source of IL-8 during urinary tract infection.
尿路感染会激活黏膜炎症反应，其中包括细胞因子分泌和中性粒细胞流入。中性粒细胞流入所涉及的机制尚未明确。白细胞介素-8是一种对中性粒细胞有效的趋化因子，可在体外由尿路上皮细胞系产生。本研究分析了人体对故意性大肠杆菌尿路感染的白细胞介素-8反应。在膀胱内灌注大肠杆菌之前和之后采集尿液和血清样本。对未离心的尿液进行中性粒细胞计数，并通过酶联免疫吸附测定法测量白细胞介素-8水平。细菌灌注后在所有患者中均发现尿液白细胞介素-8反应，但未检测到血清白细胞介素-8。尿液白细胞介素-8水平与尿液中性粒细胞数量之间存在很强的相关性。用于使患者定植的相同大肠杆菌菌株刺激尿路上皮细胞产生白细胞介素-8。上皮细胞系分泌的白细胞介素-8水平受大肠杆菌菌毛特性的影响。这些结果表明，大肠杆菌在人体中引发黏膜白细胞介素-8反应，并提示白细胞介素-8参与脓尿的发生。上皮细胞可能是尿路感染期间白细胞介素-8的重要来源。
