Cytokine and chemokine map of peripheral specific immune cell subsets in Parkinson's disease

Abstract

Background: Peripheral immune cells play a vital role in the development of Parkinson's disease (PD). However, their cytokine and chemokine secretion functions remain unclear. Objective: To explore the cytokine and chemokine secretion functions of specific immune cell subtypes in drug-naïve patients with PD at different ages of onset. Methods: We included ten early-onset and ten late-onset patients with PD and age-matched healthy controls (HCs). We used mass cytometry to select specific immune cell subsets and evaluate intracellular cytokine and chemokine expression. Statistical tests included t-tests, analysis of variance, bivariate correlation analysis, and linear regression analysis. Results: Compared with HCs, patients with PD exhibited significantly decreased intracellular pro-inflammatory cytokines and chemokines in selected clusters (e.g., tumor necrosis factor [TNF]-α, interleukin [IL]-8, IL-1β, and CC-chemokine ligand17). Specific cytokines and cell clusters were associated with clinical symptoms. TNF-α played an important role in cognitive impairment. Intracellular TNF-α levels in the naïve CD8+ T-cell cluster C16 (CD57-naïve CD8+T) and natural killer (NK) cell cluster C32 (CD57-CD28-NK) were negatively correlated with Montreal Cognitive Assessment scores. The C16 cluster affected cognitive function and motor symptoms. Increased TNF-α and decreased interferon-γ expression in C16 correlated with increased Unified Parkinson’s Disease Rating Scale III scores in patients with PD. Conclusions: We developed a more detailed cytokine and chemokine map of peripheral specific CD8+ T-cell and NK cell subsets, which revealed disrupted secretory function in patients with PD and provided unique clues for further mechanistic exploration.