Discovery of Potent, Dual-Inhibitors of Diacylglycerol Kinases Alpha and Zeta Guided by Phenotypic Optimization.

We describe a phenotypic screening and optimization strategy to discover compounds that block intracellular checkpoint signaling in T-cells. We identified dual DGKα and ζ inhibitors notwithstanding the modest similarity between α and ζ relative to other DGK isoforms. Optimized compounds produced cytokine release and T-cell proliferation consistent with DGK inhibition and potentiated an immune response in human and mouse T-cells. Additionally, lead inhibitor demonstrated dose-dependent immune stimulation in the mouse OT-1 model, setting the stage for a drug discovery program.