Department of Microbiology and Immunology, Loyola University Chicago, Stritch School of Medicine, Building 105, Room 3818, 2160 S. First Avenue, Maywood, IL 60153, USA.
J Virol. 2011 Jan;85(1):146-55. doi: 10.1128/JVI.01265-10. Epub 2010 Oct 27.
Adenovirus type 5 (Ad5) infection of macrophages results in rapid secretion of interleukin-1β (IL-1β) and is dependent on the inflammasome components NLRP3 and ASC and the catalytic activity of caspase-1. Using lentivirus-expressed short hairpin RNA (shRNA) and competitive inhibitors, we show that Ad-induced IL-1β release is dependent upon Toll-like receptor 9 (TLR9) sensing of the Ad5 double-stranded DNA (dsDNA) genome in human cell lines and primary monocyte-derived macrophages but not in mouse macrophages. Additionally, a temperature-sensitive mutant of Ad5 unable to penetrate endosomal membranes, ts1, is unable to induce IL-1β release in TLR2-primed THP-1 cells, suggesting that penetration of endosomal membranes is required for IL-1β release. Disruption of lysosomal membranes and the release of cathepsin B into the cytoplasm are required for Ad-induced NLRP3 activation. Ad5 cell entry also induces reactive oxygen species (ROS) production, and inhibitors of ROS prevent Ad-induced IL-1β release. Ad5 activation of NLRP3 also induces necrotic cell death, resulting in the release of the proinflammatory molecule HMGB1. This work further defines the mechanisms of virally induced inflammasome activation.
腺病毒 5 型（Ad5）感染巨噬细胞会导致白细胞介素-1β（IL-1β）的快速分泌，这依赖于炎症小体成分 NLRP3 和 ASC 以及半胱天冬酶-1 的催化活性。使用慢病毒表达的短发夹 RNA（shRNA）和竞争性抑制剂，我们表明 Ad 诱导的 IL-1β 释放依赖于人细胞系和原代单核细胞衍生的巨噬细胞中 TLR9 对 Ad5 双链 DNA（dsDNA）基因组的识别，但在小鼠巨噬细胞中不依赖。此外，不能穿透内体膜的 Ad5 温度敏感突变体 ts1 不能在 TLR2 引发的 THP-1 细胞中诱导 IL-1β 释放，表明内体膜的穿透是 IL-1β 释放所必需的。溶酶体膜的破坏和组织蛋白酶 B 释放到细胞质中是 Ad 诱导 NLRP3 激活所必需的。Ad5 细胞进入还会诱导活性氧（ROS）的产生，而 ROS 的抑制剂可防止 Ad 诱导的 IL-1β 释放。Ad5 激活 NLRP3 还会诱导坏死性细胞死亡，导致促炎分子 HMGB1 的释放。这项工作进一步定义了病毒诱导的炎症小体激活的机制。
