Researchers in Germany have gained new insight into how the immune system causes damage associated with multiple sclerosis (MS), an incurable neuroinflammatory disorder. Using imaging tools which enable investigation of processes in living organisms, they were able to show a direct interaction between immune cells and neurons which plays a significant role in neuronal injury. However, this direct interaction may respond to therapeutic intervention, a new study found.
Research has shown that MS is caused by damage to the protective myelin sheath, an insulating substance that surrounds nerve processes and is critical for transmission of nerve impulses.
Research has also indicated that direct damage to neurons is prominent in early disease stages.
“The contribution of direct neuronal damage to MS pathology has been debated since the first description of the disease,” Frauke Zipp, PhD, MD, professor for University Medical Center Johannes Gutenberg University at Mainz and senior author of the study, stated in a press release. “Although many different theories about possible underlying mechanisms have been proposed — such as neuron damage being a secondary effect of the disrupted myelin sheath — actual events leading to neural damage are not well understood.”
Immune cells called Th17 cells, which have been linked to autoimmune inflammation, induced elevated calcium levels in the neurons, which in the long run are toxic to the cells. Normally, calcium within the neuron plays a crucial role in exciting nerve cells as well as muscle cells.
“Our use of in vivo imaging during disease has led to the characterization of neuronal dysfunction as early and potentially reversible, and suggests that immune-mediated disturbances of the neurons themselves contribute to multiple sclerosis, in addition to interruptions in nerve cell transmission as a result of changes to the myelin sheath,” Zipp stated. “Furthermore, immune-mediated reversible calcium increases in neurons are a potential target for future therapeutics.”