Toll-like receptor 7, Toll-like receptor 8, Toll-like receptor 9 (TLR7, TLR8, TLR9)

Toll-like receptor 7, toll-like receptor 8, and toll-like receptor 9 are endosomal pattern recognition receptors in the innate immune system that detect nucleic acids from pathogens or damaged cells. TLR7 and TLR8 primarily recognize single-stranded RNA, while TLR9 recognizes unmethylated CpG DNA motifs. Upon ligand binding, they dimerize and signal through the MyD88 pathway, leading to activation of transcription factors such as NF-κB and IRF7/3, cytokine production, and initiation of adaptive immunity. These receptors are highly expressed in various immune cells (notably plasmacytoid dendritic cells and monocytes), and have become important targets for immunotherapy in infectious disease, cancer, and autoimmunity. Owing to their central role in inflammation and immunity, both agonists and antagonists targeting TLR7, TLR8, and TLR9 are under investigation for clinical use, but careful risk management is needed due to their potential to induce systemic inflammation or exacerbate autoimmunity.

Other names

TLR7TLR8TLR9"Toll-like receptor 7/8/9"

Agonists: Activation of TLR7/8/9 induces production of cytokines, chemokines, and type I interferons, enhancing innate and adaptive immunity and promoting tumor antigen-specific responses Can modulate MyD88/NF-κB and IRF3/7 signaling pathways to shift immune cell phenotype, migration, and activation Antagonists (investigational): Block pathogenic overactivation in autoimmunity