G10 is a direct activator of human STING

The cGAS/STING pathway initiates an innate immune response when DNA is detected in the cytosol. DNA bound cGAS synthesizes cyclic dinucleotides which bind and activate the adaptor STING, leading to downstream secretion of Type I interferons and other pro-inflammatory NF kappa B pathway cytokines. In the mouse, the STING driven innate immune response is central to immune based clearance of various tumors and this has triggered a significant effort focused on the discovery of human STING agonists for the treatment of cancer. This report uses an in vitro kinase assay to show that G10, a previously identified STING pathway activator is actually a weak but direct STING agonist and identifies other more potent leads.