Current opinions and perspectives on the role of immune system in the pathogenesis of Parkinson's disease.

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by the degeneration of dopamine neurons in the substantia nigra pars compacta. To date, although a bulk of evidences suggest that the etiology of PD is multifactorial, none of the mechanisms yet proposed have been considered conclusive. Activated glia seem to play a critical role in the degeneration of nigral dopaminergic neurons in PD, by secreting a complex array of cytokines, chemokines, proteolytic enzymes, reactive oxygen/nitrogen species and complement proteins that may have deleterious effects on the dopaminergic system. Recently, it has been reported that microglia activation and immunity are key factors contributing to disease progression. Here, we review studies on the role of inflammation mediated by the innate and adaptive immune systems involved in the pathogenesis of PD and highlight some of the important areas for future investigation.