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 <i>Mycobacterium tuberculosis</i>, 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.