Quantitative target engagement of RIPK1 in human whole blood via the cellular thermal shift assay for potential pre-clinical and clinical applications
In a recent collaboration between AbbVie Chemical Biology and Pelagoo Bioscience, CETSA® was applied to quantify direct target engagement of several inhibitors in unprocessed human whole blood. The study investigated RIPK1 as a proof-of-concept target, showcasing the high sensitivity and robustness of the CETSA-based assays.
Abstract
The cellular thermal shift assay (CETSA) is a target engagement method widely used for preclinical characterization of small molecule compounds. CETSA has been used for semi quantitative readouts in whole blood with PBMC isolation, and quantitative, plate-based readouts using cell lines. However, there has been no quantitative evaluation of CETSA in unprocessed human whole blood, which is preferred for clinical applications.
Here we report two separate detection technologies– AlphaLISA™ and MSD® – that require less than 100 mL of whole blood per sample without PBMC isolation. We chose RIPK1 as a proof-of-concept target and, by measuring engagement of seven different inhibitors, demonstrate high assay sensitivity and robustness. These quantitative CETSA platforms enable possible applications in preclinical pharmacokinetic-pharmacodynamic studies, and direct target engagement with small molecules in clinical trials.