Fig. 3
From: The Trojan horse - neuroinflammatory impact of T cells in neurodegenerative diseases
Potential mechanisms, by which T cells contribute to PD pathogenesis. Different mechanisms were recently described, by which T cells could contribute to PD pathogenesis, including direct and indirect interaction of T cells with neurons. Direct interactions could be mediated by Fas-FasL signaling [56] or by interaction of LFA1 with ICAM [68]. Besides, T cells could indirectly contribute to PD pathogenesis by influencing the microglial phenotype, shifting an anti-inflammatory (M2 Microglia) phenotype to a pro-inflammatory (M1 Microglia) or vice versa [57]. Moreover, α-synuclein aggregates might be presented to and activate T lymphocytes [36], thereby triggering an autoimmune inflammation, which in turn would exacerbate PD pathology possibly by imbalance of effector Th subsets, such as Treg vs. Th17 cells [69, 70]