The original role of immunity is to recognize foreign substances such as pathogens, neutralize them, and eliminate them.However, sometimes we misidentify the components of our body as foreign substances and launch attacks.Diseases caused by these causes are called autoimmune diseases, and one of the diseases that damages the central nervous system is multiple sclerosis.Normally, the blood vessels that connect to the brain have barriers that prevent unnecessary passage, including immune cells.However, in multiple sclerosis, many immune cells pass through the barrier and inflame the brain.There was a need to elucidate the full picture of the disease and why immune cells cross the barrier to establish a cure.

　The group conducted experiments with mice that developed multiple sclerosis.As a result, we found that a substance called RANKL, which is a substance used by immune cells to communicate with each other, is the cause of inflammation. When we observed mice that could not make RANKL, immune cells did not pass through the blood-brain barrier and inflammation of the central nervous system was kept low.Furthermore, based on this result, when a drug that inhibits the production of RANKL was orally administered, it succeeded in suppressing the onset of the disease.

　In this way, we have clarified the mechanism by which inflammation occurs in the central nervous system in multiple sclerosis, and at the same time, we have obtained great clues as to the treatment method. Targeting RANKL, it is expected that disease control methods and treatment methods will be established in humans.