A) Structure of compound 7, left, and HEK hTLR7 or hTLR8 cell response to compound 7, right. HEK hTLR7 or hTLR8 cells were subjected to treatment with increasing concentrations of compound 7 followed by determination of relative NF-κB activity versus control using a QuantiBlue colorimetric assay. Graphs represent three separate experiments ± SEM. EC50 in each cell line, outlined under structure, was determined by non-linear curve fitting. B) PBMCs from each indicated species were subjected to treatment with increasing concentrations of compounds 2, 4 or 7 for 24 h followed by assessment of IFNα and TNFα cytokine production from supernatants by ELISA. Human PBMC graphs represent average response from three separate donors ± SEM. Pig PBCM graphs represent average response from two replicates ± SD.