Intracellular dipeptidyl peptidase 9 (DPP9) interactions in primary human blood cells: how are they influenced by novel DPP9 inhibitors and PROTACs?

Inflammation is an immune response in which the cytosolic multiprotein complexes, inflammasomes, are crucial signaling platforms. Only recently, a master inflammasome regulator has been uncovered: the widely distributed intracellular serine protease dipeptidyl peptidase 9 (DPP9). More specifically, DPP9 is a binding partner and a negative regulator of two related Pathogen Recognition Receptors (PRRs), named 'NLRP1' and 'CARD8'. Precise insight into the mechanism is lacking as no selective DPP9 inhibitors have been reported to date. Interestingly, our preliminary data indicate that there are some differences in DPP9 (co)localization/complex formation with these PRRs among different human blood cell types. UAntwerp developed promising DPP9 inhibitors (Benramdane S, submitted) and PROTACs (heterobifunctional molecules that target a protein to degradation), creating a momentum to characterize and validate them for use in a cellular context. This PhD's overarching goal is to apply the two best DPP9 inhibitors to visualize [DPP9-CARD8] and [DPP9-NLRP1] interactions in situ in primary human blood cells and, at the molecular level, to determine the binding parameters of these interactions, both in the absence and presence of the best DPP9 inhibitors. To check whether effects are 'on-target', control experiments using PROTACs and a DPP9-/- cell line will be included. Understanding DPP9-inflammasome-related protein interactions is required to evaluate their potential as drug-targets.

Keywords:DIPEPTIDYL PEPTIDASE 9

Disciplines:Inflammation, Proteins, Molecular medicine