Think about the hobbies you have. It may be running or weight lifting, playing music or drawing. Now, think about your work. Does it involve writing or typing? Do you have to drive to get there every day?

Many of our jobs and hobbies require fine motor skills and coordinated movement, and most of the time, we don’t even think about it. We are able to type on our computers, go for a morning run and do the chores around the house without having to concentrate too much on our coordination. Unfortunately, this is not the reality for people living with Parkinson’s disease. To them, the simplest tasks may be impossible to complete.

Parkinson’s disease is a debilitating neurodegenerative disease that causes progressive problems with movement due in part to the aggregation of a protein called a-synuclein in the brain. It is often defined by tremors even at rest, rigidity, bradykinesia or slow movement, and postural instability. As the disease progresses, the more severe the symptoms become, eventually resulting in the patient being unable to do much of any tasks requiring movement on their own. By 2030, it’s predicted that 1.2 million people in the U.S. will have this disease. That’s 1.2 million people who will have a debilitating disease that cannot be cured.

Aubrey Schonhoff is working to change that. A fourth-year student in the labs of Drs. David Standaert and Ashley Harms, her work focuses on the immune system: a key and fundamental system in our bodies, and its role in the development of Parkinson’s disease. Interestingly, the immune system has long been overlooked as playing a key role in Parkinson’s disease, partially because the blood-brain barrier – the protective barrier between the brain and rest of the circulating blood in the system – was thought to be nearly impenetrable by immune cells. However, Schonhoff’s work and others are proving that it’s not that simple after all.

The brain does have its own immune system in the form of microglia – specialized cells that act as macrophages in the brain, surveying the tissue and clearing debris and cellular waste. In a person with Parkinson’s disease, these microglia begin to express the protein major histocompatibility complex II (MHC-II), which is used for antigen presentation – essentially to induce immune processes in response to a foreign antigen. Additionally, histology of brains of Parkinson’s patients reveal an infiltration of T-cells; an immune cell that isn’t typically seen in large amounts in the brain. These two observations led Schonhoff to ask if this inflammatory response was contributing to neurodegeneration and if it is, can we harness it to stop the progression of Parkinson’s disease?

Using a mouse model to mimic disease, Schonhoff has begun targeting the recently characterized border-associated macrophages (BAMs) that lie in the space between the blood-brain barrier and the systemic vasculature. She has used a drug packaged into a liposome to specifically eliminate the BAMs, which results in a significant drop in infiltrating T-cells and MHC-II in the brain, suggesting that these BAMs may be the missing link between the brain and the peripheral immune system in a disease model. Her work may be paving the way for immunotherapies to be developed to stop the progression of Parkinson’s disease.

“The immune system originates outside of the brain, which makes it easy to access,” she said of the goals of her project. “Therefore if we can find out what the interactions between the brain and the immune system are, then we could hopefully find ways to manipulate the immune system to affect disease.”

Historically, developing drugs to target neurodegenerative diseases has been incredibly difficult because of the blood-brain barrier. By looking at the immune system and it’s communication with the brain, not only does Schonhoff’s work offer novel insights into the progression of Parkinson’s disease, but also presents a potentially new and accessible druggable target that can be used in the development of neurodegenerative drugs.

In the meantime, Schonhoff said to take care of your brain by eating right and getting regular exercise (yes, even during the holidays). So, put down the bowl of chips and get up and move! Your brain is counting on you.