Yao Xiaoying, Dong Guanjun, Zhu Yuzhen, Yan Fenglian, Zhang Hui, Dai Jun, Li Xuehui, Xiong Huabao, Si Chuanping
School of Medicine and Life Sciences, University of Jinan- Shandong Academy of Medical Sciences, Jinan 250062; Institute of Immunology and Molecular Medicine, Jining Medical University, Jining 272067, China.
Institute of Immunology and Molecular Medicine, Jining Medical University, Jining 272067, China.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi. 2018 Nov;34(11):961-968.
Objective To study the effect of CD11b agonist leukadherin-1 (LA1) on the aggregation and immunosuppressive function of myeloid-derived suppressor cells (MDSCs) and its therapeutic effect on the condition of endotoxic shock mice. Methods The percentages of MDSCs , granulocytic myeloid-derived suppressor cells(G-MDSCs)and monocytic myeloid-derived suppressor cells(M-MDSCs)in spleen were detected by flow cytometry, after C57BL/6 female mice were injected of LA1 to activate through abdominal cavity for 12 hours and 48 hours. MDSCs were induced from the femur and tibia of C57BL/6 female mice in vitro. The expression levels of immunosuppressive related factors, such as interleukin 10 (IL-10), NADPH oxidase 1 (NOX1) and inducible nitric oxide synthase (iNOS) , were detected by real time quantitative PCR. C57BL/6 female mice were randomly divided into PBS group, LA1 group, PBS combined LPS group and LA1 combined LPS group. Flow cytometry was utilized to detect the ratio changes of MDSCs, G-MDSCs and M-MDSCs as well as the expression of CD86 and CD40 in macrophage, hematoxylin-eosin staining of lung and liver was utilized to detect the pathological injury, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling(TUNEL)was used to detect the apoptosis of pneumonocyte and hepatocyte and mortality analysis was reflected the severity of the disease. Based on the above indicators, we analyzed the effects of LA1 on the aggregation of MDSCs and the condition of mice in endotoxic shock. Results The ratio of MDSCs was increased by LA1 treatment for 12 and 48 hours. Further analysis of the proportions of G-MDSCs showed that LA1 treatment for 12 hours increased the proportions of G-MDSCs compared with the control group. In vitro, mRNA levels of IL-10, NOX1 and iNOS were increased after LA1 treatment in MDSCs. In vivo experiments, compared with the PBS combined LPS group, the proportions of MDSCs and G-MDSCs in LA1 combined LPS group were increased, the injuries of liver and lung were alleviated, the mortalities were reduced, and the activations of macrophage were decreased. Conclusion The activation of CD11b by LA1 alleviates endotoxin shock by promoting the aggregation of MDSCs and the expression of immunosuppressive related factors.
目的 研究CD11b激动剂白细胞黏附素-1(LA1)对髓源性抑制细胞(MDSCs)聚集及免疫抑制功能的影响及其对内毒素休克小鼠病情的治疗作用。方法 将C57BL/6雌性小鼠腹腔注射LA1激活12小时和48小时后,采用流式细胞术检测脾脏中MDSCs、粒细胞性髓源性抑制细胞(G-MDSCs)和单核细胞性髓源性抑制细胞(M-MDSCs)的百分比。体外从C57BL/6雌性小鼠的股骨和胫骨中诱导MDSCs。采用实时定量PCR检测白细胞介素10(IL-10)、NADPH氧化酶1(NOX1)和诱导型一氧化氮合酶(iNOS)等免疫抑制相关因子的表达水平。将C57BL/6雌性小鼠随机分为PBS组、LA1组、PBS联合LPS组和LA1联合LPS组。利用流式细胞术检测MDSCs、G-MDSCs和M-MDSCs的比例变化以及巨噬细胞中CD86和CD40的表达,采用苏木精-伊红染色检测肺和肝的病理损伤,采用末端脱氧核苷酸转移酶介导的dUTP-生物素缺口末端标记法(TUNEL)检测肺细胞和肝细胞的凋亡,死亡率分析反映疾病的严重程度。基于上述指标,分析LA1对MDSCs聚集及内毒素休克小鼠病情的影响。结果 LA1处理12小时和48小时后MDSCs比例增加。进一步分析G-MDSCs比例发现,LA1处理12小时后G-MDSCs比例较对照组增加。体外实验中,LA1处理MDSCs后IL-10、NOX1和iNOS的mRNA水平升高。体内实验中,与PBS联合LPS组相比,LA1联合LPS组MDSCs和G-MDSCs比例增加,肝和肺损伤减轻,死亡率降低,巨噬细胞活化减少。结论 LA1激活CD11b可通过促进MDSCs聚集及免疫抑制相关因子表达减轻内毒素休克。