The aggregation of a protein called alpha-synuclein is thought to play a role in the death of dopaminergic neurons in Parkinson’s disease.

In a new study, T-cells from patients with Parkinson’s mounted an immune response against a protein alpha-synuclein whereas immune cells from people without Parkinson’s did not. It is thought that the immune system tries to get rid of the toxic alpha-synuclein aggregates in neurons but ends up killing those neurons instead.

The researchers also think that T-cells may first identify alpha-synuclein in the nervous system of gut then enter the brain where they begin attacking dopaminergic neurons. These findings raise the possibility for an immunotherapy-based treatment.