Autoimmune neurologic diseases
Background:Accumulating evidence now suggests that the immune system plays important roles in the pathogenesis of Parkinson’s disease (PD). In preliminary work, abnormal T cell responses have been described in the circulation of patients with PD. The aim of the current study was to comprehensively immunophenotype different immune cell subsets in the patients with PD and controls.
Method:Peripheral blood were collected from patients with PD (n=34) as well as age and sex matched controls (n=17). Multi-color flow cytometry using validated panels of up to 16 parameters capturing a broad range of immune-related molecules was performed blindly on either whole blood leukocytes or peripheral blood mononuclear cells (PBMC) to deeply characterized distinct immune-cell subsets and their ex-vivo responses.
Result:The percentage of CD4+T cells was decreased (p=0.008), while CD8+T-cell frequencies increased (p=0.0015) in the PD patients, resulting in a decrease of CD4/CD8 ratios (p=0.002). Of note, PD patients seemed to harbor more CD28-CD27-CD57+KLRG1+immunosenescent T cells in their peripheral blood (p=0.05). In keeping with T cell compartment changes, PD patients also harbored increased frequencies of age-associated CD11c+ B-cells (p=0.009), while frequencies of newly generated transitional B cells with immune-regulatory capacity were decreased in the PD group (p=0.0072).
Conclusion:Taken together, our data indicate that the aging of particular T cell and B cell compartments seems to be accelerated in PD, which may offer an explanation for the pro-inflammatory immune-response profile implicated in these patients. Further functional and mechanistic cellular-immune study is warranted in PD.