School of Medicine Publications

Document Type

Article

Publication Date

7-2026

Abstract

Altered immune function is increasingly recognized as a contributor to Alzheimer's disease (AD); however, it remains unclear whether peripheral immune alterations reflect constitutive inflammation or stimulus-dependent changes in immune responsiveness. Addressing this distinction is critical for understanding immune dysregulation in neurodegenerative diseases. In this study, we applied a challenge-based ex vivo immune profiling approach to characterize functional immune responsiveness in patients with AD and in cognitively healthy older adults. Peripheral blood mononuclear cells were exposed to defined innate, antigenic, and mitogenic stimuli, and cytokine and β-amyloid (Aβ) responses were quantified in culture supernatants. Diagnosis-by-stimulus interaction effects were assessed using generalized estimating equation models, adjusted for age and sex. In parallel, exploratory correlation-based immune-amyloid network analyses and hypothesis-driven immunogenetic stratification were performed to investigate biomarker coordination patterns and context-dependent genetic influence. Baseline cytokine concentrations showed limited between-group differences, whereas ex vivo immune challenge revealed selective stimulus-dependent alterations in cytokine production. In contrast, immune stimulation revealed selective amplification of stimulus-evoked responses in AD, particularly involving interferon gamma (IFN-γ), interleukin (IL)-4, and IL-10, whereas classical proinflammatory cytokines retained preserved inducibility. Exploratory genotype-stratified analyses suggested potential context-dependent differences in functional immune and Aβ responses to immune challenges. Together, these findings indicate that peripheral immune dysregulation in AD is characterized by stimulus-dependent differences in cytokine production that become apparent under immune challenge conditions, highlighting the value of ex vivo immune stimulation assays in translational immunology in neurodegenerative diseases.

Comments

Copyright © 2026, © The Author(s) 2026.  This article is available under the Creative Commons CC-BY-NC license and permits non-commercial use, distribution and reproduction in any medium, provided the original work is properly cited.

Creative Commons License

Creative Commons Attribution-NonCommercial 4.0 International License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License

Publication Title

The Journals of Gerontology: Series A

DOI

10.1093/gerona/glag166

Academic Level

faculty

Mentor/PI Department

Neuroscience

Included in

Neurosciences Commons

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