中文摘要：

目前，關于全身性感染引發膿毒癥中過度炎癥反應和免疫功能障礙的機制尚不清楚。細胞外組蛋白會加劇膿毒癥病理進程，但其來源和作用機制仍不明確。本研究揭示，中性粒細胞來源的髓過氧化物酶通過抑制組蛋白釋放，在調控脾巨噬細胞捕獲的真菌和細菌過程中發揮膿毒癥緩解作用。在系統性念珠菌感染中，吞噬受體SIGNR1介導的微生物捕獲通過促進邊緣區浸潤和T細胞死亡依賴性組蛋白釋放，中和了髓過氧化物酶活性。組蛋白和菌絲可誘導鄰近CD169+巨噬細胞產生細胞因子（包括G-CSF），這些因子通過縮短成熟Ly6G高表達中性粒細胞的存活時間，選擇性耗竭該類細胞，轉而促進具有氧化爆發缺陷的未成熟Ly6G低表達中性粒細胞存活。在膿毒癥患者血漿中，這些介質可縮短成熟中性粒細胞壽命，并與中性粒細胞死亡標志物相關。因此，高G-CSF水平和中性粒細胞壽命縮短活性與膿毒癥患者死亡率密切相關。綜上，病原體通過利用吞噬受體，借助下游效應因子對中性粒細胞壽命的有害影響，削弱了先天性和適應性免疫功能。

英文摘要：

The mechanisms linking systemic infection to hyperinflammation and immune dysfunction in sepsis are poorly understood. Extracellular histones promote sepsis pathology, but their source and mechanism of action remain unclear. Here, we show that by controlling fungi and bacteria captured by splenic macrophages, neutrophil-derived myeloperoxidase attenuates sepsis by suppressing histone release. In systemic candidiasis, microbial capture via the phagocytic receptor SIGNR1 neutralizes myeloperoxidase by facilitating marginal zone infiltration and T cell death-dependent histone release. Histones and hyphae induce cytokines in adjacent CD169 macrophages including G-CSF that selectively depletes mature Ly6Ghigh neutrophils by shortening their lifespan in favour of immature Ly6Glow neutrophils with a defective oxidative burst. In sepsis patient plasma, these mediators shorten mature neutrophil lifespan and correlate with neutrophil mortality markers. Consequently, high G-CSF levels and neutrophil lifespan shortening activity are associated with sepsis patient mortality. Hence, by exploiting phagocytic receptors, pathogens degrade innate and adaptive immunity through the detrimental impact of downstream effectors on neutrophil lifespan.

論文信息：

論文題目：

Microbe capture by splenic macrophages triggers sepsis via T cell-death-dependent neutrophil lifespan shortening

期刊名稱：Nature Communications

時間期卷：13, Article number: 4658 (2022)

在線時間：2022年8月9日

DOI：doi.org/10.1038/s41467-022-32320-1

產品信息：

貨號：CP-005-005

規格：5ml+5ml

品牌：Liposoma

產地：荷蘭

名稱：Clodronate Liposomes and Control Liposomes

辦事處：Target Technology（靶點科技）

氯膦酸鹽脂質體清除脾臟巨噬細胞在膿毒血癥模型中心粒細胞功能研究，荷蘭Liposoma巨噬細胞清除劑Clodronate Liposomes見刊于Nature Communications：

氯膦酸二鈉脂質體清除巨噬細胞助力脾臟膿毒癥模型免疫研究

Liposoma巨噬細胞清除劑Clodronate Liposomes氯膦酸二鈉脂質體的材料和方法：

Induction of peripheral Ly6Glow neutrophils in na?ve mice

Mice were injected intravenously with 1?mg of Clo-L or PBS-L (Liposoma) and the subsequent day intraperitoneally with 2.5?μg rG-CSF (BioLegend) or vehicle (PBS). Analysis of neutrophil populations was performed 2?days after rG-CSF injection, according to the methods described in flow cytometric analysis.

Neutrophil and macrophage depletion in vivo

Neutrophil depletion was achieved with intraperitoneal injection of 150?μg anti-Ly6G Ab (BioXCell) or IgG isotype control (BioXCell) at day ?1 and day 0 (day of infection). Macrophage depletion was performed with intravenous administration of 1?mg Clodronate liposomes (Clo-L) or 1?mg PBS liposomes (PBS-L) as control (Liposoma) at 1?day prior to infection.