Single-stranded oligonucleotides can inhibit cytokine production induced by human toll-like receptor 3
Single-stranded oligonucleotides can inhibit cytokine production induced by human toll-like receptor 3
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DOI：
10.1128/mcb.00308-08
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发表时间：
2008-07-01
影响因子：
5.3
通讯作者：
Kao, C. Cheng
中科院分区：
文献类型：
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作者：
Ranjith-Kumar, C. T.;Duffy, K. E.;Kao, C. Cheng
Toll样受体3（TLR 3）可以响应于双链RNA（dsRNA）配体或dsRNA模拟物poly（I-C）而发出一系列细胞因子和趋化因子的产生的信号。使用人胚肾293 T细胞系表达人TLR 3，我们确定多聚（I-C）诱导的信号可以被单链DNA（ssDNAs）显著抑制，而不是ssRNA或dsDNA。下调TLR 3信号传导的ssDNA分子不影响TLR 4，并且不需要在TLR 9配体中发现的低甲基化CpG基序。调节的程度可以通过ssDNA的长度、碱基序列和修饰状态来改变。发现抑制性ssDNA与TLR 3在转染细胞和天然表达TLR 3的细胞系中共定位。抑制性ssDNA可以在体外与双链RNA有效竞争结合纯化的TLR 3胞外域，而非抑制性核酸则不能。ssDNA还降低由人支气管上皮细胞系BEAS-2B和由人外周血单核细胞响应天然TLR 3的多聚（I-C）刺激而产生的几种细胞因子的水平。这些活性表明ssDNA可用于通过TLR 3调节炎症反应。
Toll-like receptor 3 (TLR3) can signal the production of a suite of cytokines and chemokines in response to double-stranded RNA (dsRNA) ligands or the dsRNA mimic poly(I-C). Using a human embryonic kidney 293T cell line to express human TLR3, we determined that poly(I-C)-induced signal could be significantly inhibited by single-stranded DNAs (ssDNAs), but not ssRNA or dsDNA. The ssDNA molecules that down-modulated TLR3 signaling did not affect TLR4 and do not require the hypomethylated CpG motif found in TLR9 ligands. The degree of modulation can be altered by the length, base sequence, and modification state of the ssDNAs. An inhibitory ssDNA was found to colocalize with TLR3 in transfected cells and in a cell line that naturally expresses TLR3. The inhibitory ssDNAs can compete efficiently with dsRNA for binding purified TLR3 ectodomains in vitro, while noninhibitory nucleic acids do not. The ssDNAs also decrease the levels of several cytokines produced by the human bronchial epithelial cell line BEAS-2B and by human peripheral blood mononuclear cells in response to poly(I-C) stimulation of native TLR3. These activities indicate that ssDNAs could be used to regulate the inflammatory response through TLR3.