Weill Medical College of Cornell University, Department of Microbiology and Immunology, Molecular Biology Graduate Program, New York, New York, USA.
J Virol. 2014 Jan;88(2):974-81. doi: 10.1128/JVI.02702-13. Epub 2013 Nov 6.
Adenovirus (Ad) infection triggers a cell-specific antiviral response following exposure of viral DNA to the intracellular compartment. A variety of DNA sensors (DAI, AIM2, DDx41, RNA polymerase [Pol] III, and IFI16 [p204]) have been identified in recent years; however, the DNA sensor involved in detection of adenovirus has not been established. Cyclic GMP-AMP synthase (cGAS), a DNA sensor that produces a cyclic guanine-adenine dinucleotide (cGAMP) inducer of STING, has been examined to determine its role in generating an antiadenoviral response. Short hairpin RNA (shRNA) lentiviral vectors targeting TBK1, STING, and cGAS were established in murine MS1 endothelial and RAW 264.7 macrophage cell lines. Knockdown of TBK1, STING, and cGAS results in a dramatic reduction in the activation of the primary antiviral response marker phosphorylated interferon (IFN) response factor 3 (IRF3) following exposure to adenovirus. Furthermore, activation of secondary type I IFN signaling targets ((ptyr)STAT1 and (ptyr)STAT2 [(ptyr)STAT1/2]) was also compromised. Consistent with compromised activation of primary and secondary response markers, transcriptional activation of IRF3-responsive genes (beta IFN [IFN-β], ISG15, ISG54) and secondary response transcripts were diminished in cells knocked down in cGAS, STING, or TBK1. These data establish cGAS as the dominant cytosolic DNA sensor responsible for detection of internalized adenovirus leading to induction of the type I interferon antiviral cascade.
腺病毒（Ad）感染在病毒 DNA 暴露于细胞内隔室后触发细胞特异性抗病毒反应。近年来已经鉴定出多种 DNA 传感器（DAI、AIM2、DDx41、RNA 聚合酶 [Pol] III 和 IFI16 [p204]）；然而，尚未确定参与腺病毒检测的 DNA 传感器。环鸟苷酸-腺苷酸合酶（cGAS）是一种 DNA 传感器，可产生 STING 的环鸟苷-腺苷酸二核苷酸（cGAMP）诱导物，已对其在产生抗腺病毒反应中的作用进行了研究。靶向 TBK1、STING 和 cGAS 的短发夹 RNA（shRNA）慢病毒载体在鼠 MS1 内皮细胞和 RAW 264.7 巨噬细胞系中建立。TBK1、STING 和 cGAS 的敲低导致在暴露于腺病毒后，初级抗病毒反应标记物磷酸化干扰素（IFN）反应因子 3（IRF3）的激活显著减少。此外，二级 I 型 IFN 信号靶标（（ptyr）STAT1 和（ptyr）STAT2 [（ptyr）STAT1/2]）的激活也受到损害。与初级和次级反应标记物的激活受损一致，在 cGAS、STING 或 TBK1 敲低的细胞中，IRF3 反应基因（β IFN [IFN-β]、ISG15、ISG54）和次级反应转录物的转录激活减少。这些数据确立了 cGAS 作为负责检测内化腺病毒的主要细胞质 DNA 传感器，导致 I 型干扰素抗病毒级联反应的诱导。
