Researchers have found a new therapeutic target for Parkinson disease, a neurodegenerative disorder that impairs movement, balance, speech, and other functions.
The disease is characterized by the loss of nerves in the brain that produce a substance known as dopamine.
Although the loss of dopamine-containing nerves is accompanied by accumulation of immune cells known as T cells, these accumulating T cells were not thought to have a role in the development of disease.
However, Stephane Hunot, Etienne C. Hirsch, and colleagues, at INSERM UMR 679, France, have now shown that CD4+ T cells make a significant contribution to the development of disease in a mouse model of Parkinson disease.
For the study, a substantial number of CD4+ T cells and CD8+ T cells were observed to have accumulated in postmortem brain tissue from individuals with Parkinson disease and mice with a Parkinson-like disease.
The researchers found that mice lacking all T cells developed substantially less severe disease in the mouse model of Parkinson disease.
Further analysis indicated that protection was specifically associated with a lack of CD4+ T cells expressing the protein FasL.
The researchers suggest that targeting the immune system might provide a new therapeutic approach to treating Parkinson disease.