Assay Method Information

Assay Name:  Inhibition of the Activation Assay
Description:  As human TLR7 expressing cell line, HEK293 cell line was bought from IMGENEX Corporation (TLR7/NF-ηB/SEAPorter HEK293 cell), which is human embryonic kidney cell line and stably expresses full-length human TLR7 gene and secreted alkaline phosphatase (SEAP) reporter gene under the transcriptional control of an NE-ηB response element. The TLR7/NF-ηB/SEAPorter HEK293 cell was cultivated with DMEM containing 10% fetal bovine serum (FBS) and 10 μg/mL blasticidin S at 37° C. in the presence of 5% CO2. The TLR7/NF-ηB/SEAPorter HEK293 cell was seeded into 96-well microtiter plate at 5×104 cell/90 μL/well, and the place was cultivated at 37° C. in a CO2 incubator overnight. Each test compound that was diluted with the medium was added to the wells (10 μL/well), wherein each final concentration was adjusted to 0.001, 0.003, 0.01, 0.03, 0.1, 0.3, 1, 3, and 10 μmol/L, or 0.01, 0.03, 0.1, 0.3, 1, 3, 10, 30, and 100 μmol/L. After 0.5 hour, R-848 that is TLR7/8 ligand was added to each well (10 μL/well), wherein each final concentration was adjusted to 200 nmol/L. The total volume was adjusted to 110 μL/well, the test samples were incubated in CO2 incubator for 20±1 hours, and then the SEAP activity was measured as activation of TLR7. The SEAP activity was evaluated as follows: p-nitro-phenyl phosphate (pNPP) (Invitrogen) was added to the incubated sample (50 μL/well); after 15 minutes, 4 mol/L sodium hydroxide solution (nacalai tesque) was added thereto (50 μL/well) to quench the reaction; and the absorbance of each sample was measured at 405 nm with microplate reader Elx808 (BioTek). The 50% inhibitory concentration (IC50 value) of each sample compound was calculated based on 100% of the SEAP activity wherein the test sample comprises no sample compound.
Affinity data for this assay
 

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