C-178 is a covalent inhibitor of stimulator of interferon genes (STING).1 It binds to Cys91 on STING to block its palmitoylation and prevents recruitment and phosphorylation of TBK1 in HEK293T cells. C-178 (0.01-1.25 ?M) selectively reduces STING-, but not RIG-I- or TBK1-, mediated IFN-β reporter activity in HEK293 cells. It also prevents increases in Ifnb1 expression in bone marrow-derived macrophages (BMDMs) induced by cyclic di-GMP , double-stranded DNA, and LPS when used at a concentration of 0.5 ?M.
1.Haag, S.M., Gulen, M.F., Reymond, L., et al.Targeting STING with covalent small-molecule inhibitorsNature559(7713)269-273(2018)