Research from our team indicates that immune cells may play central roles in the development of Parkinson’s disease (PD). In PD, certain types of nerve cells can activate specific types of immune cells (known as T cells, which are found in the blood and lymph nodes). These T cells may kill nerve cells in PD patients’ gastrointestinal tract and brain, and the loss of nerve cells contributes to the symptoms of PD. These immunological responses will be studied in animal models and human tissue including the brains of PD patients.
We propose that, in PD, these activated T cells mistake the body’s normal nerve cells as foreign invaders (autoimmunity) and this error is critical in the initiation of PD. The interactions of T cells with nerve cells underlies the loss of specific neurons in PD, including substantia nigra dopamine neurons.
We will determine the steps that occur in T cell activation in PD by examining T cells in blood from PD patients and healthy controls, and in the gut and brain of new mouse models of PD. To examine if these cell types are in human brain, we have developed new methods to detect signals in specific cells in autopsies of PD patients.
Impact on Diagnosis/Treatment of Parkinson’s Disease:
The T cells and the molecules they use to interact with nerve cells can be used to identify people with PD before they develop symptoms, to identify ways to predict the progression of PD, treatments optimal for specific patients, and to provide new therapies by blocking steps in immune responses.