Table 1.

Summary of the signaling pathways of TLR3, 7, 8, 9, and 13

Type	Subcellular localization	Natural and synthetic ligand	Adaptor	Transcription factor	Effector cytokines	References
TLR3	Endosomes	dsRNAs, siRNAs, poly(I:C)	TRIF	NF-κB, AP-1, IRF3	Inflammatory cytokines, type I interferons	[1,2,5–7]
TLR7	Endosomes	ssRNAs, ORNs, siRNAs, imidazoquinolines	MyD88, PACSIN1	NF-κB, AP-1, IRF3/7	Inflammatory cytokines, type I interferons	[1,2,5,7–11]
TLR8	Endosomes	ssRNAs, ORNs, siRNAs, poly(A)/T, DNA, imidazoquinolines	MyD88	NF-κB, AP-1, IRF3/7	Inflammatory cytokines, type I interferons	[1,2,5,7,9,12]
TLR9	Endosomes	CpG DNAs, CpG ODNs	MyD88, PACSIN1	NF-κB, AP-1, IRF3/7	Inflammatory cytokines, type I interferons	[1,2,5,7–11]
TLR13	Endosomes	23S rRNA	MyD88	NF-κB, AP-1, IRF3/7	Inflammatory cytokines, type I interferons	[13–15]