Basic Science and Pathogenesis

Area of Science:

• Immunology
• Neuroscience
• Cell Biology

Background:

• The immune system, particularly chronic inflammation and dysfunction, is implicated in Alzheimer's disease (AD) pathogenesis.
• Helper T cell impairment may accelerate AD progression.
• Immunoglobulin-like Transcript 2 (ILT-2) is an inhibitory T cell receptor; its role in AD was investigated.

Purpose of the Study:

• To explore the relationship between ILT-2 expression on T cells and Alzheimer's disease severity.
• To investigate alterations in T cell subpopulations in AD patients.

Main Methods:

• Analysis of peripheral blood mononuclear cells (PBMCs) from 17 AD patients and 16 healthy controls using flow cytometry.
• High-dimensional data reduction and visualization via Uniform Manifold Approximation and Projection (UMAP).
• Comparison of T cell subpopulation distributions and ILT-2 expression across AD stages and controls.

Main Results:

• Significant differences in helper T cell (CD4+) subpopulation distributions were observed between AD patients and healthy controls.
• The proportion of ILT-2 negative helper T cells was reduced in both mild and moderate AD patients compared to controls.
• Moderate AD patients showed a more pronounced reduction in ILT-2 negative helper T cells.

Conclusions:

• A decreased proportion of ILT-2 negative helper T cells and an increased CD4+ILT-2+ population suggest enhanced cytotoxic function in AD.
• These T cell alterations indicate immune imbalance and could serve as biomarkers for AD progression.
• ILT-2 presents a potential therapeutic target for Alzheimer's disease interventions.