M04 acts as a stimulator of interferon genes (STING) agonist, effectively inducing IFN reporter gene expression in HEK293T cells equipped with wild-type human STING. Its activity is specific, not affecting HEK293T cells with the R71H-G230A-R293Q (HAQ) human STING variant or mouse RAW 264.7 cells, showcasing allelic- and species-dependent effects at a concentration of 75 µM. This compound also stimulates the production of TNF-alpha, IL-10, IL-1beta, and IL-12p70 in human peripheral blood mononuclear cells (PBMCs). At 50 µM, M04 enhances human monocyte-derived dendritic cells expression of HLA-DR (MHC class II receptor) and co-stimulatory molecules CD40, CD80, and CD86, improving T cell cross-priming in an ex vivo assay.
