Live-Cell Imaging Analysis of the Intracellular Behavior of the C-Type Lectin Receptor Mincle and Its Ligand Using Newly Developed Fluorescence-Labeled Molecular Probes Based on Trehalose Diester

Mincle, a member of the C-type lectin receptor (CLR) family, detects various glycolipids and glycerolipids such as trehalose dimycolate (TDM) from Mycobacterium tuberculosis, leading to the activation of the innate immune system. In this study, we developed new fluorescence-labeled molecular probes, TDE-Fluor-Ligand and TDE-Reactive-Probe, based on the structure of trehalose diester to elucidate the intracellular behavior of Mincle and its ligands. TDE-Fluor-Ligand was prepared for the ligand analysis, and TDE-Reactive-Probe was specifically designed to label Mincle by turn-on fluorescent affinity labeling. Live-cell imaging analysis using these probes revealed that TDE-Fluor-Ligand internalizes into the cell in a Mincle-dependent manner. Furthermore, imaging analysis using TDE-Reactive-Probe successfully detected Mincle in cells in a Mincle expression-dependent manner.