Recent study results have added to a growing body of evidence which suggests that the immune system plays a major role in the development of Parkinson’s disease, a neurodegenerative disease characterized by the death of dopamine-producing (dopaminergic) brain cells.
Researchers found CD4+ and CD8+ cells, types of immune system T cells, in the brains of people who had died from Parkinson’s disease. They also found that the cells accumulated in the brains of mouse models of the neurodegenerative disease. Further studied revealed that the rate of dopaminergic cell death was significantly slower in mice bred to lack CD4+ cells, thus suggesting that CD4+ cells are toxic to dopaminergic cells.
The researchers say that their findings suggest that therapeutic strategies, such as drugs or vaccines, which can prevent CD4+ cells from accumulating in brain cells might slow the progress of the disease.
Brochard V, Combadière B, Prigent A, et al. Infiltration of CD4+ lymphocytes into the brain contributes to neurodegeneration in a mouse model of Parkinson disease. J Clin Invest. Publised online December 22nd, 2008. doi:10.1172/JCI36470.