摘要
目的利用功能性PD-L1(programmed cell death ligand-1,PD-L1)单抗阻断巨噬细胞介导的PD1/PD-L1通路,研究其对小鼠结核治疗后复发的免疫干预作用和机制。方法 10~6CFU H37Rv经尾静脉感染C57BL/6雌性小鼠获得结核的急性感染,两周之后分别给予异烟肼(10 mg/kg)和异烟肼联合PD-L1单抗(每只50μg)连续治疗四周,获得潜伏感染,在潜伏期用TNF-α抗体(每只50μg)诱导四周使其复发。通过对各时间点的肺、脾和肝组织病理及荷菌量的定量分析,探讨PD-L1单抗对小鼠活动性结核及结核复发的干预作用。利用体外实验,进一步阐明敲低PD-L1对结核菌感染的巨噬细胞凋亡的影响。结果小鼠感染后,前两周肺、脾和肝荷菌量较高(3~4 Lg CFU/mL)、肉芽肿病变较重,表现为活动性结核,异烟肼和异烟肼联合PD-L1单抗分别治疗四周之后,肺、脾和肝荷菌量均较模型对照组显著性地降低,肉芽肿样病变也显著减轻,但是两个治疗组之间没有显著性的差异。而在复发期,相比较于异烟肼治疗组,异烟肼联合PD-L1单抗治疗组能够显著降低复发期组织荷菌量,减轻病理病变。体外实验证实:用PD-L1抗体或siRNA敲低巨噬细胞上PD-L1,结果发现二者都能能促进结核感染的巨噬细胞凋亡。结论功能性的PD-L1抗体可以抑制结核复发,敲低巨噬细胞上PD-L1或阻断PD1/PD-L1通路能促进巨噬细胞凋亡,提示阻断PD-L1能够有效的协助异烟肼治疗结核病,并且显著地抑制结核的复发。
Objective To study the immune intervention effect and mechanism of blockage of macrophage-mediated PD1/PD-L1 pathways with functional PD-L1(programmed cell death ligand-1,PD-L1)monoclonal antibody upon tuberculosis(TB)relapse in mice.Methods Female C57BL/6 mice were infected by tail vein injection of 10 6 CFU M.tuberculosis H37Rv to obtain active TB infection.Two weeks postinfection,the mice in different groups were administered isoniazid(10 mg/kg)(group ISO)and isoniazid combined with PD-L1 monoclonal antibody(50μg/each)(group ISO+PD-L1)respectively,continued for four weeks to obtain latent infection.The subsequent relapse was monitored.Among the treatment groups,the TB relapse was induced by TNF-αantibody(50 ug/each)for four weeks from the beginning of latent stage.At each scheduled time point,bacterial loads and pathological changes in the lung,spleen and liver were quantitatively analyzed,thereby,the in vivo intervention effect of PD-L1 monoclonal antibody on tuberculosis recurrence in mice was revealed.The in vitro experiment was further explored whether knock-down the expression of PD-L1 on the infected macrophages could accerlate the macrophage apoptosis.Results The bacterial burden reached 3-4 Lg(CFU/mL),and granuloma lesions were extensive in the lung,spleen and liver in the all infected groups,which appeared as active TB stage at 2nd week postinfection.After treated,the bacterial burden of the lung,spleen and liver was decreased,and the pathological lesions alleviated in the group ISO and group ISO+PD-L1,compared with the model control group,showing significant differences,but there was no significant difference between the two treatment groups.However,compared with the group ISO,the group ISO+PD-L1 had a significantly lower bacterial load and milder pathological lesions during the relapse period.Futhermore,knock-down the expression of PD-L1 on macrophages with anti-PD-L1 or PD-L1-siRNA promoted apoptosis in macrophages.Conclusions Blockade of the PD1/PD-L1 pathway by PD-L1 functional antibody can
作者
孙萌萌
秦川
唐军
占玲俊
SUN Mengmeng;QIN Chuan;TANG Jun;ZHAN Lingjun(Institute of Laboratory Animal Science,Chinese Academy of Medical Sciences(CAMS);Key Laboratory of Human Disease Animal Models,State Administration of Traditional Chinese Medicine;Key Laboratory of Human Disease Comparative Medicine,Ministry of Health;Beijing Key Laboratory for Animal Model)
出处
《中国比较医学杂志》
CAS
北大核心
2018年第4期50-58,共9页
Chinese Journal of Comparative Medicine
基金
中央级公益性事业单位院基本业务费(2016ZX310183-2)
中国医学科学院医学与健康科技创新工程项目(2016-I2M-1-031)。
关键词
PD-L1抗体干预
小鼠结核模型
结核复发
巨噬细胞凋亡
blockade with PD-L1 functional antibody
mice model of tuberculosis
tuberculosis relapse
macrophage apoptosis
