Fig. 1

T lymphocyte immunophenotyping in PD patients versus controls. A Following gating of the total lymphocyte and single cell populations, CD4⁺ and CD8⁺ T cells were identified as CD3⁺CD4⁺ and CD3⁺CD8⁺, respectively. CD4⁺ and CD8⁺ subsets were distiguished using a quadrant gate based on the expression of CCR7 and CD45RA. Additionally, senescent CD8⁺ subsets were identified based on their low expression of CD28 and high expression of CD57. B Quantification of CD8⁺ T cell subets in PD patients and controls. There was a significant decrease in the absolute number of CD8⁺ TEMRA cells in patients versus controls (two-tailed unpaired Welch's t-test, t(87.25) = 2.392, p = 0.019). All other CD8⁺ T cell subsets did not differ between the groups (two-tailed unpaired Welch's t-test, p > 0.05). CM: Central memory, EM: effector memory, TEMRA: terminally differentiated effector memory cells re-expressing CD45RA. *p < 0.05