白介素17及其受体在大鼠重症肺炎克雷伯菌肺炎中的表达

目的 探讨白介素17(interleukin-17,IL-17)及IL-17受体(interleukin-17 receptor,IL-17R)在大鼠重症肺炎克雷伯菌肺炎发病过程中的表达.方法 72只SD大鼠随机分为模型组和对照组,通过气管内注射肺炎克雷伯菌3.6×10~9cfu/只,建立大鼠重症肺炎模型,采用实时荧光定量PCR方法检测各时间点肺组织IL-17、IL-17R、IL-1β、肿瘤坏死因子α mRNA表达水平;动态观察支气管肺泡灌洗液白细胞总数和中性粒细胞分类计数,并取肺组织病理学观察.结果 IL-17及IL-17R mRNA的表达于造模后4 h开始升高,第3天达到高峰,分别为对照组的(282.32±21.22)倍、(18.01±0.67)倍(P<0.01),至第7天基本降至基础水平.IL-1β及肿瘤坏死因子α mRNA的表达高峰延迟于IL-17及IL-17R,于第5天达到高峰.IL-17 mRNA的表达量与支气管肺泡灌洗液中性粒细胞计数呈显著正相关(r=0.82,P<0.01).模型组肺组织明显充血、水肿及出血,于第3天出现显著炎症细胞浸润.结论 IL-17及其受体在重症肺炎中高表达,是参与重症肺炎克雷伯菌肺炎发生发展的重要细胞因子,其促炎作用与上调中性粒细胞聚集及刺激IL-1β、肿瘤坏死因子α等细胞因子表达有关.

Expression of interleukin-17 and its receptor in rats with severe pneumonia induced by Klebsiella pneumoniae

Objective To investigate the expression of interleukin-17 (IL-17) and IL-17 receptor (IL-17R) in rats with severe pneumonia induced by Klebsiella pneumoniae. Methods Seventy-two SD rats were randomly devided into model group and control group. The rat model of severe pneumonia was established by intratracheally injected with 3.6×10~9 cfu Klebsiella pneumoniae per rat. The mRNA expressions of IL-17, IL-17R, IL-1β and tumor necrosis factor-α (TNF-α) in lung tissue at the set time were assayed by fluorescent quantitative real-time PCR. The total white blood cells and neutrophils in the bronchoalvolar lavage fluid (BALF) were detected. The histopathology of lung tissue was observed. Results IL-17 and IL-17R mRNA levels began rising at the 4th hour after modeling and peaked at the 3rd day,and were (282.32±21.22) times, (18.01±0.67) times of those of control group(P <0.01) ,while dropped to basic level at the 7th day. IL-1β and TNF-α mRNA levels peaked at the 5th day after modeling, later than the expressions of IL-17 and IL-17R. IL-17 mRNA expression in the lung tissue was positively correlated with the count of neutrophils in BALF (r = 0.82, P<0.01). Hyperemia, edema and bleeding appeared in the lung tissue of model group,and inflammatory cells markedly infiltrated at the 3th day. Conclusions IL-17 and its receptor highly express in the severe pneumonia,which are important cytokines in the occurrence and development of the severe pneumonia induced by Klebsiella pneumoniae. The pro-inflammatory role of them is related to increasing neutrophil aggregation and stimulating expression of IL-1β,TNF-α and other cytokines.