Fig. 1: Trafficking of NA-sensing TLRs and downstream signals induced by nucleic acid recognition in endosomes.
From: Understanding nucleic acid sensing and its therapeutic applications
TLR9 is first trafficked to the plasma membrane and then internalized into the endosome via AP2, where TRIF is recruited to activate downstream transcription factors. TLR7 and TLR9 depend on AP4 for localization to the endosome to activate the TAK1 signaling pathway via the recruitment of MyD88. AP3 further mediates TLR localization to lysosome-related organelles (LROs), where type I IFN gene activation is mediated.
