肖淑妍 1薛丰沅 2季殷敏 3吕雅晖 2董怡 1胡毅4
作者信息
- 1. 中国人民解放军医学院 临床医学系,北京 100853||中国人民解放军总医院第一医学中心 肿瘤内科,北京 100853
- 2. 中国人民解放军医学院 临床医学系,北京 100853
- 3. 中国人民解放军总医院第五医学中心肿瘤医学部,北京 100039
- 4. 中国人民解放军总医院第一医学中心 肿瘤内科,北京 100853||中国人民解放军总医院第五医学中心肿瘤医学部,北京 100039
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摘要
Abstract
Objective:To investigate the therapeutic effect and molecular mechanism of mesenchymal stromal cell-derived extracellular vesicles(MSC-EV)on immune checkpoint inhibitor-related pneumonitis(CIP)in a mouse model.Methods:Foxp3DTR mice were inoculated with MC38 mouse colon cancer cells and randomly divided into 3 groups(n=6 per group):① control group(MC38 inoculation only);② CIP model group(inoculated with MC38 cells,intraperitoneally injected with diphtheria toxin[DT]and anti-PD-1 antibody);③ MSC-EV intervention group(based on the CIP model,intranasally administered with MSC-EV[dose 109 particles/mouse,every 3 days,2 times in total]).A mouse CIP model induced by Treg depletion combined with anti-PD-1 antibody was established.In vivo,H-E staining was used to observe lung pathological injury,lung wet/dry ratio was measured to assess pulmonary edema,ELISA was used to detect IL-1β,IL-6,and TNF-α levels in bronchoalveolar lavage fluid(BALF),and flow cytometry was used to detect the proportion of Ly6G ⁺ granulocyte infiltration in BALF.Tumor volume was monitored to evaluate antitumor efficacy.In vitro,DiO fluorescent labeling was used to observe the uptake of extracellular vesicles(EVs)by bone marrow-derived macrophages,and WB assay was used to detect the expression levels of key NLRP3 inflammasome proteins(cleaved GSDMD and mature IL-1β).Potential mechanisms were explored using GEO database miRNA sequencing data(GSE69909),Dicer knockdown,and miR-21/miR-125 inhibitor intervention.Results:Intranasal administration of MSC-EV alleviated lung inflammatory injury in CIP model mice,reduced IL-1β,IL-6,and TNF-α levels and the proportion of Ly6G⁺ granulocyte infiltration in BALF(P<0.05),without compromising the antitumor efficacy of anti-PD-1 antibody therapy.In vitro DiO labeling tracing showed that MSC-EV could be taken up by macrophages.WB assay showed that MSC-EV decreased the levels of key activated proteins(cleaved GSDMD and mature IL-1β)of the NLRP3 inflammasome(P<0.05).In vitro,after Dicer knockdown,the MSC-EV showed a weakened downregulation effect on IL-1β in macrophages(P<0.05).miRNA sequencing(GEO database,GSE69909)showed high expression of miR-21 and miR-125 in MSC-EV,and inhibition of miR-21 or miR-125 reduced the inhibitory effect of the corresponding MSC-EV on IL-1β cleavage in macrophages(P<0.05).Conclusion:MSC-EV exert anti-inflammatory effects through their carried miRNAs such as miR-21 and miR-125,and the mechanism may be related to inhibition of NLRP3 inflammasome activation in macrophages,thereby effectively alleviating CIP without compromising the antitumor efficacy of immune checkpoint inhibitor.关键词
细胞外囊泡/间充质基质细胞/免疫检查点抑制剂相关肺炎/巨噬细胞/NLRP3炎症小体Key words
extracellular vesicle(EV)/mesenchymal stromal cell(MSC)/immune checkpoint inhibitor-related pneumonitis(CIP)/macrophage/NLRP3 inflammasome分类
医药卫生
