Ficolin通过激活补体加重poly(I:C)联合LPS诱导的急性肺脏损伤  

Ficolin aggravates acute lung injury induced by poly(I:C)combined with LPS stimulation by activating complement

作　　者：胡子琪 吴旭 姚朵朵 李燕秀 孙志夫 王玺 张须龙(指导)[1] HU Ziqi;WU Xu;YAO Duoduo;LI Yanxiu;SUN Zhifu;WANG Xi;ZHANG Xulong(Department of Immunology,School of Basic Medical Sciences,Capital Medical University,Beijing 100069,China)

机构地区：[1]首都医科大学基础医学院免疫学系,北京100069

出　　处：《中国免疫学杂志》2022年第14期1665-1670,共6页Chinese Journal of Immunology

基　　金：国家自然科学基金面上项目(82071747);北京市自然科学基金面上项目(7182013)。

摘　　要：目的:探究纤维胶凝素(ficolin)在poly(I:C)联合LPS刺激诱导的急性肺损伤中的作用及机制。方法:6~8周龄SPF级C57BL/6小鼠和ficolin基因敲除小鼠分别随机分组,连续2 d滴鼻50μg/d poly(I:C),然后50μg/d滴鼻LPS 1 d,构建poly(I:C)和LPS联合刺激诱导的急性肺损伤小鼠模型,单独刺激或滴鼻PBS为对照组;HE染色检测肺组织病理变化;流式细胞术检测每组小鼠肺组织中性粒细胞和巨噬细胞的比例变化;Western blot检测每组小鼠肺组织和RAW264.7细胞中C3的表达变化和活化情况。结果:成功建立了poly(I:C)联合LPS刺激诱导的急性肺损伤小鼠模型。联合刺激组小鼠肺脏病理损伤加重,肺泡融合和弥漫性损伤,大量炎症细胞浸润;其中中性粒细胞和间质巨噬细胞比例显著提高,肺泡巨噬细胞比例显著降低。联合刺激增加小鼠肺组织和RAW264.7细胞中补体C3的表达和酶解活化,而敲除ficolin可明显降低联合刺激诱导的C3活化,并减少间质巨噬细胞募集和肺泡巨噬细胞耗竭,改善急性肺损伤。结论:Ficolin可通过激活补体加重poly(I:C)联合LPS刺激介导的肺脏炎症和急性肺损伤,是重症肺炎潜在的治疗靶点。Objective:To investigate the effect and mechanisms of ficolin in acute lung injury induced by poly(I:C)combined with LPS stimulation.Methods:6~8 weeks of SPF grade C57BL/6 and ficolin knockout mice were randomly assigned and inoculated intranasally with 50 μg/d poly(I:C)for 2 days and subsequently with 50 μg/d LPS for 1 day to establish a mouse model of acute lung injury induced by co-stimulation of poly(I:C)and LPS,and poly(I:C)or LPS alone or PBS administration was used as control groups. HE staining was used to detect pathological changes of lung tissue. Flow cytometry was used to detect the proportions of neutrophils and macrophages in lung tissue. Western blot was used to detect the expression and activation of C3 in lung tissue and RAW264.7 cell line.Results:A mouse model of acute lung injury induced by combined treatment with poly(I:C)and LPS was successfully established. Combined stimulation aggravated lung pathological injury,increased pulmonary alveolar fusion and a large number of inflammatory cells infiltration. Besides,the proportions of neutrophils and interstitial macrophages were significantly increased,and the proportion of alveolar macrophages was significantly decreased. Combined stimulation enhanced the expression and enzymatic activation of complement C3 in mouse lung tissue and RAW264.7 cells,while knockout of ficolin reduced the C3 activation induced by combined stimulation,inhibited the recruitment of interstitial macrophages and the exhaustion of alveolar macrophages,and improved the acute lung injury.Conclusion:Ficolin can aggravate pulmonary inflammation and acute lung injury induced by poly(I:C)combined with LPS stimulation through activation of complement,which is a potential therapeutic target for severe pneumonia.

关 键 词：Poly(I:C) LPS 补体活化 C3 FICOLIN 

分 类 号：R392[医药卫生—免疫学]