Splenic T lymphocytes induce the formation of immunosuppressive neutrophils through IFN-γ in sepsis
Splenic T lymphocytes induce the formation of immunosuppressive neutrophils through IFN-γ in sepsis
复制标题
DOI：
10.1007/s00011-021-01524-4
复制
发表时间：
2021-11-28
影响因子：
6.7
通讯作者：
Sun, Bingwei
中科院分区：
文献类型：
--
作者：
Huang, Jiamin;Sun, Ran;Sun, Bingwei
背景：尽管脓毒症的治疗取得了许多进展，但患者的预后仍然很差。中性粒细胞(PMN)是抵御感染的第一道防线。本研究旨在揭示脓毒症时产生PD-L1(+)中性粒细胞的原因和机制。方法建立盲肠结扎穿孔小鼠模型。中性粒细胞分别在加入或不加入100 ng/mL干扰素的条件下处理4h、12h，进行基因测序。采用多重免疫荧光法检测PD-L1、PD-1、Ly6G和CD3。流式细胞仪检测PD-L1的表达及中性粒细胞的功能。用双抗体夹心法测定血清和细胞培养上清液。Western印迹法验证JAK2/STAT1通路。结果我们的研究表明，在脓毒症中，PMN是高表达PD-L1的主要免疫细胞，因此这些细胞在免疫抑制中起着关键作用。体内研究表明PD-L1(+)PMN与PD-1(+)T细胞之间存在特异性相互作用。体外研究进一步证实，干扰素通过JAK2/STAT1途径诱导PD-L1(+)PMN的产生。此外，JAK2的抑制剂Fedratinib可显著降低中性粒细胞中PD-L1的表达。结论在脓毒症中，脾T淋巴细胞分泌干扰素-γ可通过JAK2/STAT1途径诱导PD-L1+PMN的产生。
Background Despite many advances in treatment, the prognosis of patients with sepsis still remains poor. Polymorphonuclear leukocytes (PMNs) are the first line of defense against infection. This study aimed to reveal the reason and mechanism of the production of PD-L1(+) PMNs in sepsis.Methods Cecal ligation and perforation mouse model was established to simulate sepsis. And PMNs were treated for 4 h, 12 h with or without 100 ng/mL (IFN-gamma) for further gene sequencing. PD-L1, PD-1, Ly6G, and CD3 were detected by multiplexed immunofluorescence. In addition, expression of PD-L1 and function of PMNs were assessed by flow cytometry. Serum and cell culture supernatant were measured with ELISA assays. Western blot was used to verify the JAK2/STAT1 pathway.Results Our study demonstrates that PMNs are the main immune cells with high expression of PD-L1 during sepsis, and these cells, therefore, play a critical role in immunosuppression. In vivo studies demonstrated a specific interaction between PD-L1(+) PMNs and PD-1(+) T cells. In vitro studies further demonstrated that IFN-gamma induced the production of PD-L1(+) PMNs through the JAK2/STAT1 pathway. In addition, Fedratinib, an inhibitor of Jak2, was shown to significantly reduce the expression of PD-L1 in neutrophils.Conclusions These data demonstrate that secretion of IFN-gamma by splenic T lymphocytes induces the production of PD-L1 + PMNs through the JAK2/STAT1 pathway in sepsis.