Researchers at La Jolla Institute for Immunology (LJI) are investigating how the immune system may contribute to Parkinson’s disease, and they hope to help develop better diagnostics and more effective therapies.
LJI Professor Alessandro Sette, Dr. Biol. Sci. and Research Assistant Professor Cecilia Lindestam Arlehamn, Ph.D., have uncovered evidence that Parkinson’s disease is indeed partly an autoimmune disease.
In 2017, the researchers showed that clumps of a protein called alpha-synuclein can act as beacons for certain T cells, causing them to mistakenly attack brain cells and potentially contribute to the progression of Parkinson’s. This was the first direct evidence that autoimmunity could play a role in Parkinson’s disease.
In a 2020 study, the LJI team shed light on the timeline of T cell reactivity and disease progression. The researchers looked at blood samples from a large group of Parkinson’s disease patients and compared their T cells to a healthy, age-matched control group. They found that the T cells that react to alpha-synuclein are most abundant when patients are first diagnosed with the disease. These T cells tend to disappear as the disease progresses, and few patients still have them ten years after diagnosis. This research shows that signs of autoimmunity can appear in Parkinson’s disease patients years before their official diagnosis.
In 2022, Sette and Lindestam Arlehamn published research showing that people with Parkinson’s disease have memory T cells with a very specific gene signature, and genes associated with targeting alpha-synuclein may very well be causing ongoing inflammation in cases of Parkinson’s.
These breakthroughs could make it possible to someday detect Parkinson’s disease before the onset of debilitating motor symptoms—and potentially intervene with therapies to slow the disease progression.