mRNA Is an Endogenous Ligand for Toll-like Receptor 3

作者：Katalin Karikó, Houping Ni, John Capodici, Marc S. Lamphier, Drew Weissman · 发表于：Journal of Biological Chemistry · 年份：2004 · DOI：10.1074/jbc.m310175200 · 被引用次数：1063 · 研究领域：Immune Response and Inflammation、Immune Cell Function and Interaction、Immunotherapy and Immune Responses

Toll-like receptors (TLRs) are the basic signaling receptors of the innate immune system. They are activated by molecules associated with pathogens or injured host cells and tissue. TLR3 has been shown to respond to double stranded (ds) RNA, a replication intermediary for many viruses. Here we present evidence that heterologous RNA released from or associated with necrotic cells or generated by in vitro transcription also stimulates TLR3 and induces immune activation. To assess RNA-mediated TLR3 activation, human embryonic kidney 293 cells stably expressing TLR3 and containing a nuclear factor-kappaB-dependent luciferase reporter were generated. Exposing these cells to in vitro transcribed RNA resulted in a TLR3-dependent induction of luciferase activity and interleukin-8 secretion. Treatment with in vitro transcribed mRNA activated nuclear factor-kappaB via TLR3 through a process that was dose-dependent and involved tyrosine phosphorylation. Furthermore, in vitro transcribed natural or 2'-fluoro-substituted mRNA induced the expression of TLR3, interferon regulatory factor-1, tumor necrosis factor-alpha, and interleukin-1 receptor-associated kinase-M mRNA in human dendritic cells (DCs). DCs responded to mRNA treatment by expressing activation markers, and this maturation was inhibited by antagonistic TLR3-specific antibody. Endogenous RNA released from or associated with necrotic cells also stimulated DCs, leading to interferon-alpha secretion, which could be abolished by pre...