Thrombospondin-1 Restricts Interleukin-36γ-Mediated Neutrophilic Inflammation during Pseudomonas aeruginosa Pulmonary Infection.
Thrombospondin-1 Restricts Interleukin-36γ-Mediated Neutrophilic Inflammation during Pseudomonas aeruginosa Pulmonary Infection.
复制标题
DOI：
10.1128/mbio.03336-20
复制
发表时间：
2021-04-06
期刊：
影响因子：
6.4
通讯作者：
Lee JS
中科院分区：
文献类型：
--
作者：
Peñaloza HF;Olonisakin TF;Bain WG;Qu Y;van der Geest R;Zupetic J;Hulver M;Xiong Z;Newstead MW;Zou C;Alder JK;Ybe JA;Standiford TJ;Lee JS
铜绿假单胞菌肺部感染可导致过度的嗜酸性炎症和组织破坏，但调节嗜酸性反应的宿主因素尚不完全清楚。IL-36γ是一种促炎细胞因子，其在蛋白酶的N-末端加工后生物活性显著增加。白细胞介素-36 γ（IL-36γ）是IL-1细胞因子超家族的成员，在急性肺铜绿假单胞菌感染时可增强肺部炎症反应并损害宿主防御。为了具有完全活性，IL-36γ在其N-末端区域被蛋白酶如中性粒细胞弹性蛋白酶（NE）和组织蛋白酶S（CatS）切割。然而，目前尚不清楚限制细胞外蛋白水解是否抑制了铜绿假单胞菌感染期间由IL-36γ触发的炎症级联反应。血小板反应蛋白-1（TSP-1）是一种基质细胞蛋白，对NE和病原体分泌的假单胞菌弹性蛋白酶LasB具有抑制活性，这两种蛋白酶都与炎症放大有关。我们假设TSP-1通过抑制IL-36γ活化所需的蛋白水解环境来缓和肺铜绿假单胞菌感染期间的炎症反应。与野生型（WT）小鼠相比，TSP-1缺陷型（Thbs 1 −/−）小鼠在铜绿假单胞菌感染期间在肺部表现出高度炎症反应，细胞因子产生增加，细胞外蛋白水解环境不受限制，其特征在于更高的游离NE和LasB，但不是CatS活性。LasB在M19近端切割IL-36γ的切割位点与NE和CatS产生的切割位点不同，NE和CatS分别在Y16和S18近端切割IL-36γ。计算机模拟的N-末端截短实验预测M19和S18同种型几乎相同地结合IL-36 R复合物。在铜绿假单胞菌感染期间，IL-36γ中和作用改善了Thbs 1 −/−小鼠的炎症反应，并提高了肺免疫力。此外，给予裂解的IL-36γ诱导细胞因子产生和中性粒细胞募集和活化，这在Thbs 1 −/−小鼠肺中加重。总的来说，我们的数据表明TSP-1调节肺嗜酸性炎症，并通过抑制IL-36γ活化所需的细胞外蛋白水解环境来促进宿主防御。
Pseudomonas aeruginosa pulmonary infection can lead to exaggerated neutrophilic inflammation and tissue destruction, yet host factors that regulate the neutrophilic response is not fully known. IL-36γ is a proinflammatory cytokine that dramatically increases in bioactivity following N-terminal processing by proteases. Interleukin-36γ (IL-36γ), a member of the IL-1 cytokine superfamily, amplifies lung inflammation and impairs host defense during acute pulmonary Pseudomonas aeruginosa infection. To be fully active, IL-36γ is cleaved at its N-terminal region by proteases such as neutrophil elastase (NE) and cathepsin S (CatS). However, it remains unclear whether limiting extracellular proteolysis restrains the inflammatory cascade triggered by IL-36γ during P. aeruginosa infection. Thrombospondin-1 (TSP-1) is a matricellular protein with inhibitory activity against NE and the pathogen-secreted Pseudomonas elastase LasB—both proteases implicated in amplifying inflammation. We hypothesized that TSP-1 tempers the inflammatory response during lung P. aeruginosa infection by inhibiting the proteolytic environment required for IL-36γ activation. Compared to wild-type (WT) mice, TSP-1-deficient (Thbs1−/−) mice exhibited a hyperinflammatory response in the lungs during P. aeruginosa infection, with increased cytokine production and an unrestrained extracellular proteolytic environment characterized by higher free NE and LasB, but not CatS activity. LasB cleaved IL-36γ proximally to M19 at a cleavage site distinct from those generated by NE and CatS, which cleave IL-36γ proximally to Y16 and S18, respectively. N-terminal truncation experiments in silico predicted that the M19 and the S18 isoforms bind the IL-36R complex almost identically. IL-36γ neutralization ameliorated the hyperinflammatory response and improved lung immunity in Thbs1−/− mice during P. aeruginosa infection. Moreover, administration of cleaved IL-36γ induced cytokine production and neutrophil recruitment and activation that was accentuated in Thbs1−/− mice lungs. Collectively, our data show that TSP-1 regulates lung neutrophilic inflammation and facilitates host defense by restraining the extracellular proteolytic environment required for IL-36γ activation.