AffinityImmuno Products

Introduction

TREM2 is a single-pass membrane receptor found on microglia, macrophages, osteoclasts, and dendritic cells that must pair with the adaptor protein TYROBP/DAP12 to relay signals into the cell. Through this partnership it recognizes a range of ligands, including amyloid-beta aggregates, anionic phospholipids, and lipoprotein particles carrying apolipoproteins such as APOE, and drives the engulfment of these materials along with apoptotic neurons, damaged myelin, and unwanted synaptic connections. Biallelic loss-of-function mutations in the TREM2 gene cause a rare recessive syndrome combining early bone cysts and fractures with a progressive presenile dementia and white-matter degeneration, while other coding variants are established risk factors for late-onset Alzheimer’s disease. Given this dual role in skeletal and microglial biology, TREM2 is studied both as a marker of neurodegeneration and as a potential target for modulating microglial activity.

TREM2 is both an established Alzheimer’s risk gene and an actively pursued drug target for boosting protective microglial activity — though it’s worth framing honestly, since the TREM2 agonist antibody AL002 did not show a treatment benefit in its recent Phase 2 INVOKE-2 trial, making soluble TREM2 more valuable right now as a research biomarker of microglial activation than as a validated drug-response marker.

Principle of the Assay

This kit uses a sandwich enzyme immunoassay format in which the microtiter plate wells are pre-coated with a capture antibody specific to Human TREM2. Standards or samples are added to the appropriate wells together with a biotin-conjugated detection antibody that also recognizes Human TREM2. Avidin conjugated to horseradish peroxidase (HRP) is then added to each well and allowed to incubate. Upon addition of TMB substrate solution, a colorimetric signal develops exclusively in wells containing Human TREM2, the biotin-conjugated detection antibody, and avidin-HRP. The enzymatic reaction is stopped by the addition of sulphuric acid solution, and absorbance is measured spectrophotometrically at 450 nm ± 10 nm. Human TREM2 concentrations in the samples are determined by referencing the measured optical densities against a standard curve.