For millions of people in the United States, nerve damage from neurodegenerative diseases, serious injuries, and certain eye conditions leads to disability and death. Physicians currently consider such damage permanent.
However, researchers at the Wexner Medical Center of Ohio State University have discovered a new form of human immune cell in the optic nerve and spinal cord that appears to prevent and reverse nerve damage.
This discovery could allow more advanced neurodegenerative immunotherapies to be developed by researchers.
These treatments may bring new hope to people with neurological disorders that are currently incurable, including Alzheimer’s disease , multiple sclerosis, stroke, and Parkinson’s disease. They may also aid in treating damage to the central nervous system ( CNS) from injury or infection.
According to Dr. Benjamin Segal, professor and chair of the Department of Neurology at The Ohio State College of Medicine and co-director of the Ohio State Wexner Medical Center’s Neurological Institute, “I treat patients who have lifelong neurological deficits and have to deal with crippling symptoms every day.”
“So the idea of being able to restore neurological function and take that burden away from my patients is really amazing . ”
The study appears in the journal Nature Immunology and is sponsored by the National Eye Institute (NEI), the National Institutes of Health ( NIH), the Wings of Life Foundation (C.Y.), and the Dr. Miriam and Sheldon G. Adelson Research Foundation.
The emerging field of immunotherapy
Immunotherapy treatments change the immune response by stimulating it or treating infection by using the body’s own immune cells. Scientists have started designing them over the past few decades to combat a wide variety of medical conditions.
Immunotherapy is now used by physicians to treat some forms of cancer. They help to identify and kill cancer cells in the immune system.
Other researchers are studying whether neurological disorders may be avoided or treated by immunotherapy.
Immunotherapies that improve the clearance rate of such proteins whose aggregation is related to neurological disorders such as Alzheimer’s disease , Parkinson ‘s disease, frontotemporal dementia and Lewy body dementia have been extensively tested by researchers.
T-cell mediated immunotherapy approaches that target proteins associated with these neurological disorders, such as amyloid-beta, tau, and alpha-synuclein proteins, have already been developed by scientists.
By stimulating alternate immune pathways in response to CNS injury, immunotherapy can also present opportunities to prevent and treat nerve damage.
A research in 2014 found that macrophages that are anti-inflammatory or immunoregulatory (M2) are essential for remyelination, which is a type of nerve repair.
In fluids and spinal cord tissues obtained from mice with optic and spinal nerve damage, the researchers examined immune cells.
The team identified a special kind of granulocyte inside these fluids and tissues. A type of white blood cells is called granulocytes. The most common kind of granulocytes are neutrophils.
Scavengers that help kill viruses or other unwanted particles in the body are neutrophils. The new form of granulocyte described by the researchers behaved like an immature neutrophil.
This newly identified granulocyte helped shield the mice from damage to neural cells and tissues. It has also facilitated the regeneration of nerve cells by secreting a mixture of beneficial growth compounds. A human cell line with similar neuroprotective properties was also identified by the team.
To save dying nerve cells, this sort of cell actually secretes growth factors. The surviving nerve cells can also be stimulated to develop new fibers after they are severed or destroyed in the [CNS], which is truly unparalleled, says Dr. Segal. “For a wide variety of disorders, this can eventually lead to therapeutic breakthroughs by restoring these nerve pathways.”
Researchers, though, have a long way to go before doctors can use immune cells to treat humans, like this recently discovered granulocyte.
The first big challenge for the team would be to find out how to harness this new immune cell ‘s strength and boost its natural healing effects by developing it in a laboratory setting. Next, they will have to show that their newly proposed therapy in humans is both successful and effective.
In the future, the team hopes that these novel cells will be introduced into people with chronic cognitive disabilities by doctors to delay or avoid degenerative deterioration.
Dr. Segal concludes that they have a lot of work left to do in a clinical setting to make their laboratory results meaningful, but says he is positive about the path ahead:
“There’s so much that we’re learning at the bench that has yet to be translated to the clinic, but I think there’s huge potential for the future.”