Related Experiment Video
Updated: Jun 13, 2026
Methods for the Discovery of Novel Compounds Modulating a Gamma-Aminobutyric Acid Receptor Type A Neurotransmission
Published on: August 16, 2018
Identification of a novel aβ-overlapping binding site on the TREM2 Ectodomain engaged by the small-molecule agonist
Sungwoo Cho1, Moustafa T Gabr1
1Department of Radiology, Molecular Imaging Innovations Institute (MI3), Weill Cornell Medicine, New York, NY 10065, USA.
Abstract:
Triggering receptor expressed on myeloid cells 2 (TREM2) is a microglial immune receptor genetically and functionally linked to Alzheimer's disease (AD). VG-3927, the first small-molecule TREM2 agonist to enter clinical development, has been proposed to act as a transmembrane molecular glue and positive allosteric modulator (PAM), but whether it also engages the TREM2 ectodomain has not been systematically explored. Here, we used DiffDock-L, a deep learning-based blind docking algorithm, to map potential VG-3927 binding sites across the TREM2 structure and identified a binding site within the ectodomain hydrophobic groove, a ligand-recognition surface previously implicated in Aβ and apoE binding. Microscale thermophoresis (MST) confirmed VG-3927 interaction with TREM2 under optimized polyethylene glycol 400 (PEG-400) buffer conditions and showed that Aβ1-42 binds directly to TREM2. In the presence of Aβ, the VG-3927 MST signal was reduced, supporting interference at an overlapping ectodomain binding surface. Consistently, Aβ induced a rightward shift in the VG-3927 dose-response curve in a Jurkat TREM2-DAP12 Nuclear Factor of Activated T Cells (NFAT) reporter assay and attenuated VG-3927-induced phospho-spleen tyrosine kinase (p-SYK) signaling. Together, these findings support the presence of a previously unrecognized ectodomain interaction mode for VG-3927 and suggest that amyloid-associated ligand occupancy may modulate TREM2 agonist activity in the AD microenvironment.
Insights
VG-3927, an Alzheimer's disease drug, may bind to the TREM2 receptor's ectodomain. This binding site overlaps with amyloid-beta, potentially altering the drug's effectiveness in the AD microenvironment.
Area of Science:
- Neuroscience
- Immunology
- Pharmacology
Background:
- Triggering receptor expressed on myeloid cells 2 (TREM2) is a key microglial immune receptor implicated in Alzheimer's disease (AD).
- VG-3927 is a novel small-molecule agonist for TREM2, currently in clinical development for AD.
- The precise mechanism of VG-3927, particularly its interaction with the TREM2 ectodomain, remains incompletely understood.
Purpose of the Study:
- To investigate potential binding sites of VG-3927 on the TREM2 receptor, focusing on the ectodomain.
- To determine if VG-3927 interacts with TREM2 in a manner influenced by amyloid-beta (Aβ), a hallmark of AD.
- To elucidate the functional consequences of VG-3927's interaction with TREM2, especially in the context of Aβ binding.
Main Methods:
- Utilized DiffDock-L, a deep learning-based blind docking algorithm, to predict VG-3927 binding sites on TREM2.
- Employed Microscale Thermophoresis (MST) to confirm direct binding of VG-3927 and Aβ1-42 to TREM2.
- Conducted a Jurkat TREM2-DAP12 Nuclear Factor of Activated T Cells (NFAT) reporter assay to assess functional effects and signaling modulation.
Main Results:
- Identified a novel binding site for VG-3927 within the TREM2 ectodomain hydrophobic groove, a region known to bind ligands like Aβ.
- Confirmed direct binding of VG-3927 to TREM2 and Aβ1-42 to TREM2 using MST.
- Observed that Aβ binding interferes with VG-3927 binding to TREM2 and attenuates VG-3927-mediated signaling (p-SYK), shifting the dose-response curve in reporter assays.
Conclusions:
- VG-3927 engages the TREM2 ectodomain via a previously unrecognized binding mode.
- Amyloid-beta binding to TREM2 can modulate the activity of the TREM2 agonist VG-3927.
- These findings have implications for understanding TREM2-targeted therapies in the context of the Alzheimer's disease microenvironment.
