Monocyte activation by necrotic cells is promoted by mitochondrial proteins and formyl peptide receptors.
Monocyte activation by necrotic cells is promoted by mitochondrial proteins and formyl peptide receptors.
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DOI：
10.1097/ccm.0b013e3181a001ae
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发表时间：
2009-06
影响因子：
8.8
通讯作者：
Wewers MD
中科院分区：
文献类型：
--
作者：
Crouser ED;Shao G;Julian MW;Macre JE;Shadel GS;Tridandapani S;Huang Q;Wewers MD
坏死细胞通过不明确的机制唤起强大的先天免疫反应。细胞的线粒体部分保留了其细菌祖先的成分，包括具有潜在免疫原性的n -甲酰基肽。因此，我们假设细胞的线粒体部分，特别是n -甲酰基肽，对坏死细胞激活单核细胞有重要贡献。人外周血单核细胞与坏死细胞组分和线粒体蛋白孵育，以研究其免疫细胞激活的潜力。大学医学中心研究实验室。健康的成年人充当献血者。用坏死HepG2细胞或n -甲酰基肽缺失的坏死HepG2细胞[Rho(0)细胞]的细胞质、细胞核和线粒体部分处理后，测量人血液单核细胞活化情况。高亲和力甲酰基肽受体（FPR）的特定作用，然后使用特定的药理学抑制剂和rna沉默来测试。线粒体n -甲酰基肽激活单核细胞的能力通过与线粒体NADH亚基6的n端一致的合成肽得到证实。结果表明，线粒体细胞组分最有效地激活单核细胞，IL-8在低蛋白浓度下选择性释放。来自Rho(0)细胞的线粒体诱导少量单核细胞IL-8释放，特异性药理抑制剂和rna沉默证实，FPR显著促进单核细胞对坏死细胞和线粒体蛋白的IL-8反应。n -甲酰基肽不能诱导单核细胞释放IL-8；然而，线粒体n -甲酰基肽和线粒体转录因子A （TFAM）的结合显著增加了单核细胞中IL-8的释放。同样，HMGB1， TFAM的核同源物，除非与线粒体n -甲酰基肽结合，否则不会诱导单核细胞释放IL-8。在其他线粒体抗原（如TFAM）存在的情况下，线粒体n -甲酰基肽和FPR之间的相互作用对坏死细胞活化单核细胞有重要作用。
Necrotic cells evoke potent innate immune responses through unclear mechanisms. The mitochondrial fraction of the cell retains constituents of its bacterial ancestors, including N-formyl peptides, which are potentially immunogenic. Thus, we hypothesized that the mitochondrial fraction of the cell, particularly N-formyl peptides, contributes significantly to the activation of monocytes by necrotic cells. Human peripheral blood monocytes were incubated with necrotic cell fractions and mitochondrial proteins in order to investigate their potential for immune cell activation. University medical center research laboratory. Healthy human adults served as blood donors. Human blood monocyte activation was measured after treatment with cytosolic, nuclear and mitochondrial fractions of necrotic HepG2 cells or necrotic HepG2 cells depleted of N-formyl peptides [Rho(0) cells]. The specific role of the high affinity formyl peptide receptor (FPR) was then tested using specific pharmacological inhibitors and RNA-silencing. The capacity of mitochondrial N-formyl peptides to activate monocytes was confirmed using a synthetic peptide conforming to the N-terminus of mitochondrial NADH subunit 6. The results demonstrated that mitochondrial cell fractions most potently activated monocytes, and IL-8 was selectively released at low protein concentrations. Mitochondria from Rho(0) cells induced minimal monocyte IL-8 release, and specific pharmacological inhibitors and RNA-silencing confirmed that FPR contributes significantly to monocyte IL-8 responses to both necrotic cells and mitochondrial proteins. N-formyl peptides alone did not induce monocyte IL-8 release; whereas, the combination of mitochondrial N-formyl peptides and mitochondrial transcription factor A (TFAM) dramatically increased IL-8 release from monocytes. Likewise, HMGB1, the nuclear homologue of TFAM, did not induce monocyte IL-8 release unless combined with mitochondrial N-formyl peptides. Interactions between mitochondrial N-formyl peptides and FPR in the presence of other mitochondrial antigens (e.g., TFAM) contributes significantly to the activation of monocytes by necrotic cells.