Single-cell transcriptomics reveals the interaction between peripheral CD4 CTLs and mesencephalic endothelial cells mediated by IFNG in Parkinson's disease.

Parkinson's disease (PD) is characterized by dopaminergic neurons degeneration in the substantia nigra pars compacta. Increasing evidence indicates that peripheral CD4 T cells, a vital pathological component of PD, have been implicated in systemic inflammation activation, blood-brain barrier (BBB) dysfunction, central nervous system infiltration, and consequent neurons degeneration. However, there is no consensus on CD4 T cell types' exact phenotypic characteristics in systemic inflammation and the mechanism of CD4 T cells traffic into the BBB in patients with PD.