HEK-Blue™ TLR7 cells are designed to monitor the TLR7 (Toll-Like Receptor 7)-dependent NF-κB and AP-1 responses.
These cells express the human or murine TLR7 gene. In addition, they feature an NF-κB/AP-1-inducible SEAP reporter gene. SEAP (secreted embryonic alkaline phosphatase) levels produced upon TLR7 stimulation can be readily determined by performing the assay in HEK-Blue™ Detection, a cell culture medium that allows for real-time detection of SEAP. Alternatively, SEAP activity may be monitored using QUANTI-Blue™ solution, a SEAP detection reagent.
TLR7 is a pattern recognition receptor (PRR) mainly located in the endosome. Together with TLR8, it and recognizes single-stranded (ss)RNA structures and 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 [2, 3].
TLR7 agonists are currently been tested as vaccine adjuvants and immunomodulatory therapeutics .
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.
5. Georg P. & Sander L.E., 2019. Innate sensors that regulate vaccine responses. Curr. Op. Immunol. 59:31.