"Our findings raise the possibility that an immunotherapy approach could be used to increase the immune system's tolerance for alpha-synuclein ..."

NeuroscienceNews article: "Parkinson's is Partly an Autoimmune Disease"

Parkinson's is Partly an Autoimmune Disease - Neuroscience News
(hat tip to 999---666 at HU for this link)

Research paper: "T cells from patients with Parkinson's disease recognize alpha-synuclein peptides", Sulzer, D. et al. Nature (2017), doi:10.1038/nature22815

T cells from patients with Parkinson’s disease recognize α-synuclein peptides : Nature : Nature Research
(abstract only, rest is behind the paywall)

This research builds on earlier work reported in a 2014 paper, which contains some good background information.

Research paper: "MHC-I expression renders catecholaminergic neurons susceptible to T-cell-mediated degeneration", Cebrian, C. et al. Nature Communications 5, 3633 (2014), doi:10.1038/ncomms4633

MHC-I expression renders catecholaminergic neurons susceptible to T-cell-mediated degeneration | Nature Communications
(this is an open-access research paper)