TLR-Mediated Secretion of Endoplasmic Reticulum Aminopeptidase 1 from Macrophages
TLR-Mediated Secretion of Endoplasmic Reticulum Aminopeptidase 1 from Macrophages
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DOI：
10.4049/jimmunol.1300935
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发表时间：
2014-05-01
影响因子：
4.4
通讯作者：
Tsujimoto, Masafumi
中科院分区：
文献类型：
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作者：
Goto, Yoshikuni;Ogawa, Kenji;Tsujimoto, Masafumi
巨噬细胞在几种免疫、炎症和/或感染条件下在宿主防御中发挥重要作用。在我们以前的工作中，我们证明了内质网氨基肽酶1(ERAP1)是由巨噬细胞分泌的，它响应于内毒素和干扰素-γ，并增强了巨噬细胞的吞噬活性。本研究分析了内毒素/干扰素-γ诱导ERAP1分泌的机制。多粘菌素B抑制脂多糖/干扰素-γ诱导的小鼠巨噬细胞株RAW264.7分泌该酶。几种TLRs激动剂如Pam3CSK4、FSL-1和ODN1826可诱导该酶的分泌。相反，中和干扰素-β和肿瘤坏死因子-α受体1型抗体则抑制其分泌。利用来自肿瘤坏死因子-α和1型IFNR基因敲除小鼠的小鼠腹膜巨噬细胞，我们证实了这两种细胞因子参与ERAP1的分泌。此外，A23187和thapsigargin可诱导RAW264.7细胞和小鼠腹腔巨噬细胞分泌ERAP1，而BAPTA-AM和钙调素抑制剂W7可抑制ERAP1的分泌。这些结果表明，内毒素/干扰素-γ诱导ERAP1的分泌是由TLRs介导的，TLRs通过诱导中间细胞因子如干扰素-β和肿瘤坏死因子-α，进而导致细胞内钙离子水平升高和钙调蛋白激活。
Macrophages play an important role in host defense under several immunological, inflammatory, and/or infectious conditions. In our previous work, we demonstrated that endoplasmic reticulum aminopeptidase 1 (ERAP1) was secreted from macrophages in response to LPS and IFN-gamma, and it enhanced their phagocytic activity. In this study, we analyzed the mechanism of LPS/IFN-gamma-induced ERAP1 secretion. LPS/IFN-gamma-induced secretion of the enzyme from the murine macrophage cell line RAW264.7 was suppressed by polymyxin B. Several agonists of TLRs, such as Pam3CSK4, FSL-1, and ODN1826, induced its secretion. In contrast, neutralizing Abs to IFN-beta and TNF-alpha receptor type 1 suppressed its secretion. Using murine peritoneal macrophages derived from TNF-alpha and type 1 IFNR knockout mice, we confirmed the involvement of these two cytokines in ERAP1 secretion. In addition, secretion of ERAP1 from both RAW264.7 cells and murine peritoneal macrophages was induced by A23187 and thapsigargin and inhibited by BAPTA-AM and the calmodulin inhibitor W7. These results suggest that LPS/IFN-gamma-induced secretion of ERAP1 is mediated by TLRs via induction of intermediate cytokines such as IFN-beta and TNF-alpha, which in turn lead to enhanced cytosolic Ca2+ levels and calmodulin activation.