HEK-Blue™ TLR7 cells are designed for studying the stimulation of TLR7 by monitoring the activation of NF-κB and AP-1.
TLR7 recognizes small synthetic molecules, such as loxoribine and R848, an imidazoquinoline compound .
TLR7 signaling involves the MyD88-dependent signaling cascade and induces the production of IFN-α, TNF-α and IL-12. Sequence-specific single stranded RNA (ssRNA) was identified as the natural ligand of TLR7 [2, 3].
ssRNA sequences derived from HIV-1 or the influenza virus were shown to induce the production of proinflammatory cytokines in plasmacytoid dendritic cells.
Furthermore, it has been demonstrated that TLR7 is involved in sequence-specific sensing of ssRNA in human macrophages . TLR7 signaling is abrogated by chloroquine indicating that it is dependent on endosomal acidification.
1. Hemmi H. et al., 2002. Small anti-viral compounds activate immune cells via the TLR7 MyD88-dependent signaling pathway. Nat Immunol, 3:196-200.
2. Heil F. et al., 2004. Species-specific recognition of single-stranded RNA via toll-like receptor 7 and 8. Science. 303:1526-9.
3. Diebold SS. et al., 2004. Innate antiviral responses by means of TLR7-mediated recognition of single-stranded RNA. Science. 303:1529-31.
4. Gantier MP. et al., 2008. TLR7 is involved in sequence-specific sensing of single-stranded RNAs in human macrophages. J immunol. 180; 2117-24.