Stereoselective Degradation of Diacylglycerol Kinases Potentiate T cell Activation and Tumor Cell Cytotoxicity

Abstract

Stereoselective recognition is a powerful means to differentiate selective versus non-specific activity of small molecules in complex biological systems. Here, we disclose stereochemically defined, sulfonyl-triazole inhibitors of the lipid enzyme diacylglycerol kinase-alpha (DGK), a key metabolic checkpoint for T cell effector function. Acute treatment with the covalent DGK inhibitor AHL-7160 recruited endogenous DGK to the plasma membrane in a stereoselective and isozyme-specific manner. The membrane translocation activity of AHL-7160 correlated with blockade of cellular phosphatidic acid production and potentiation of primary T cell-mediated killing of a glioblastoma cell line. Quantitative chemoproteomics revealed Y669 and K411 as sites of AHL-7160 modification on endogenous DGK in cells. Extended treatments resulted in proteasome-dependent and proteome-wide selective degradation of DGK in T cells. Collectively, these findings establish covalent DGK ligands as potent molecular glues with translational potential in immunotherapy.