Roles for the adaptive immune system in Parkinson's and Alzheimer's diseases.

Neurodegenerative diseases, such as Parkinson's and Alzheimer's, affect millions of people and pose major personal and socioeconomic burdens. The causes of neurodegeneration are mostly unknown, although current efforts have described an autoimmune aspect to these diseases. Here we discuss recent findings that shed light on the involvement of the adaptive immune system in Parkinson's and Alzheimer's diseases, and provide a model and outlook for further investigation of T cell responses in neurodegenerative disease. We focus on the identification of T cell epitopes from proteins involved in disease pathogenesis and describe the identification of α-synuclein-specific epitopes in Parkinson's disease which provided a crucial link between disease susceptibility and T cell recognition.