Comprehensive RNAi-based screening of human and mouse TLR pathways identifies species-specific preferences in signaling protein use.
Comprehensive RNAi-based screening of human and mouse TLR pathways identifies species-specific preferences in signaling protein use.
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基于 RNAi 的人类和小鼠 TLR 通路综合筛选可确定信号蛋白使用中的物种特异性偏好。
DOI：
10.1126/scisignal.aab2191
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发表时间：
2016-01-05
影响因子：
7.3
通讯作者：
Fraser ID
中科院分区：
文献类型：
--
作者：
Sun J;Li N;Oh KS;Dutta B;Vayttaden SJ;Lin B;Ebert TS;De Nardo D;Davis J;Bagirzadeh R;Lounsbury NW;Pasare C;Latz E;Hornung V;Fraser ID
Toll样受体（TLR）是介导先天免疫细胞对微生物刺激的应答的主要类型的模式识别受体。为了系统地确定基因产物在经典TLR信号通路中的作用，我们在人和小鼠巨噬细胞中进行了基于RNA干扰（RNAi）的筛选。我们观察到一种模式的保守信号模块的依赖性跨物种，但发现显着的物种特异性要求在单个基因产物的水平。其中，我们确定了人类和小鼠TLR途径之间白细胞介素1受体相关激酶（IRAK）蛋白使用的意外差异。小鼠巨噬细胞中的TLR信号传导主要依赖于IRAK4和IRAK2，IRAK1的作用很小或没有作用，而人巨噬细胞中的TLR信号传导和促炎细胞因子产生高度依赖于IRAK1，并且受IRAK4或IRAK2扰动的影响较小。人和小鼠细胞对IRAK 4损失的不同敏感性反映在IRAK 4直系同源物不能拯救来自其他物种的IRAK 4缺陷型巨噬细胞中的信号传导，以及在巨噬细胞中TLR应答中对IRAK 4激酶活性的小鼠特异性需求。我们的研究还确定了IRAK 1在人类TLR信号传导中的关键作用，这可能可以解释IRAK 1与几种自身免疫性疾病的相关性。此外，我们还展示了如何使用系统筛选来识别跨物种先天免疫反应的重要特征以及用于调节人类TLR依赖性输出的更佳治疗靶点。
Toll-like receptors (TLRs) are a major class of pattern recognition receptors, which mediate the response of innate immune cells to microbial stimuli. To systematically determine the roles of gene products in canonical TLR signaling pathways, we conducted an RNA interference (RNAi)-based screen in human and mouse macrophages. We observed a pattern of conserved signaling module dependencies across species, but found notable species-specific requirements at the level of individual gene products. Among these, we identified unexpected differences in interleukin 1 receptor-associated kinase (IRAK) protein use between the human and mouse TLR pathways. Whereas TLR signaling in mouse macrophages depended primarily on IRAK4 and IRAK2, with little or no role for IRAK1, TLR signaling and proinflammatory cytokine production in human macrophages were highly dependent on IRAK1 and were less affected by perturbations of IRAK4 or IRAK2. The differential sensitivity of human and mouse cells to the loss of IRAK4 was reflected in the inability of the IRAK4 orthologs to rescue signaling in IRAK4-deficient macrophages from the other species, and in a mouse-specific requirement for the kinase activity of IRAK4 in TLR responses in macrophages. Our study also identified a critical role for IRAK1 in TLR signaling in humans, which could potentially explain the association of IRAK1 with several autoimmune diseases. Furthermore, we demonstrated how systematic screening can be used to identify important characteristics of innate immune responses across species and more optimal therapeutic targets for regulating human TLR-dependent outputs.