Autophagy Mediates Interleukin-1β Secretion in Human Neutrophils.
Autophagy Mediates Interleukin-1β Secretion in Human Neutrophils.
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DOI：
10.3389/fimmu.2018.00269
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发表时间：
2018
影响因子：
7.3
通讯作者：
Trevani AS
中科院分区：
文献类型：
--
作者：
Iula L;Keitelman IA;Sabbione F;Fuentes F;Guzman M;Galletti JG;Gerber PP;Ostrowski M;Geffner JR;Jancic CC;Trevani AS
白细胞介素1受体(IL-1β，IL-1β)是一种主要的促炎细胞因子，是一种无引导性胞浆蛋白，其分泌不遵循经典的内质网-高尔基体途径，其分泌机制尚待建立。中性粒细胞是对抗细菌和真菌感染的关键因素。这些细胞从循环中迅速大量招募到受感染的组织中，不仅展示了令人印象深刻的有毒武器库，有效地杀死病原体，而且在感染条件下也是IL-1β的重要来源。在这里，我们分析了非传统的分泌自噬机制是否参与了这些细胞输出IL-1β的过程。我们的结果表明，用3-甲基腺嘌呤和Wortmannin抑制自噬能显著减少内毒素β诱导的IL-1 + 的分泌，用Bafilmycin A1和E64d阻断自噬通量也是如此。这些化合物对中性粒细胞活性没有明显影响，排除了对IL-1β分泌的影响是由于细胞死亡。此外，VPS34IN-1是一种特异性的自噬抑制剂，在其合成后加入VPS34IN-1仍能减少IL-1β的分泌。此外，siRNA介导的ATG5基因敲除显著降低了中性粒细胞分化的PLB985细胞中IL-1β的分泌。共聚焦显微镜观察发现，在脂多糖 + 作用下，IL-1β被掺入自噬小室。IL-1β-LC3B在培养上清液中IL-1β增加之前，囊泡内重叠达到高峰。另一方面，细胞饥饿刺激自噬增强了IL-1β和LC3B的共存，进而促进了中性粒细胞IL-1β的分泌。此外，特异性的ELISA分析表明，尽管IL-1β和前IL-1β都在中性粒细胞刺激下被释放到培养上清液中，但自噬只促进IL-1β的分泌。此外，丝氨酸蛋白酶抑制剂AEBSF可减少IL-1β的分泌。此外，IL-1β还与弹性蛋白酶共定位，提示含有IL-1β的囊泡与嗜天青颗粒内容物相交，丝氨酸蛋白酶也调节IL-1β的分泌。总之，我们的发现表明，一种非传统的自噬介导的分泌途径介导了人中性粒细胞中IL-1β的分泌。
Interleukin-1β (IL-1β), a major pro-inflammatory cytokine, is a leaderless cytosolic protein whose secretion does not follow the classical endoplasmic reticulum-to-Golgi pathway, and for which a canonical mechanism of secretion remains to be established. Neutrophils are essential players against bacterial and fungi infections. These cells are rapidly and massively recruited from the circulation into infected tissues and, beyond of displaying an impressive arsenal of toxic weapons effective to kill pathogens, are also an important source of IL-1β in infectious conditions. Here, we analyzed if an unconventional secretory autophagy mechanism is involved in the exportation of IL-1β by these cells. Our findings indicated that inhibition of autophagy with 3-methyladenine and Wortmannin markedly reduced IL-1β secretion induced by LPS + ATP, as did the disruption of the autophagic flux with Bafilomycin A1 and E64d. These compounds did not noticeable affect neutrophil viability ruling out that the effects on IL-1β secretion were due to cell death. Furthermore, VPS34IN-1, a specific autophagy inhibitor, was still able to reduce IL-1β secretion when added after it was synthesized. Moreover, siRNA-mediated knockdown of ATG5 markedly reduced IL-1β secretion in neutrophil-differentiated PLB985 cells. Upon LPS + ATP stimulation, IL-1β was incorporated to an autophagic compartment, as was revealed by its colocalization with LC3B by confocal microscopy. Overlapping of IL-1β-LC3B in a vesicular compartment peaked before IL-1β increased in culture supernatants. On the other hand, stimulation of autophagy by cell starvation augmented the colocalization of IL-1β and LC3B and then promoted neutrophil IL-1β secretion. In addition, specific ELISAs indicated that although both IL-1β and pro-IL-1β are released to culture supernatants upon neutrophil stimulation, autophagy only promotes IL-1β secretion. Furthermore, the serine proteases inhibitor AEBSF reduced IL-1β secretion. Moreover, IL-1β could be also found colocalizing with elastase, suggesting both some vesicles containing IL-1β intersect azurophil granules content and that serine proteases also regulate IL-1β secretion. Altogether, our findings indicate that an unconventional autophagy-mediated secretory pathway mediates IL-1β secretion in human neutrophils.
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影响因子：
8.7
作者：
Ramadass M;Catz SD
通讯作者：
Catz SD
影响因子：
5.5
作者：
Rorvig, Sara;Ostergaard, Ole;Borregaard, Niels
通讯作者：
Borregaard, Niels
影响因子：
5.4
作者：
Laura Gabelloni, Maria;Sabbione, Florencia;Trevani, Analia S.
通讯作者：
Trevani, Analia S.
DOI：
10.1152/ajplung.00228.2015
发表时间：
2015-10-15
影响因子：
4.9
作者：
Patankar, Yash R.;Mabaera, Rodwell;Berwin, Brent
通讯作者：
Berwin, Brent
影响因子：
4.8
作者：
Harris, James;Hartman, Michelle;Lavelle, Ed C.
通讯作者：
Lavelle, Ed C.