A team of researchers from the University of Freiburg in Germany have identified previously unknown types of immune cells which are present in the inflamed brain of an animal model of multiple sclerosis (MS). The discovery was made by means of a new, high-resolution method for analysing single cells. The method allowed the researchers to create a kind of immune cell atlas for the brain. They also showed how these cells promote the development of the autoimmune disease MS. This study was published in the journal Science.
Commenting on the discovery, project director Prof. Dr. Marco Prinz, University of Freiburg said: “Our findings constitute a breakthrough for the understanding of autoimmune diseases like MS. We hope that it will now be possible to develop new, more cell-specific therapeutic approaches that are less prone to side-effects for treating inflammatory diseases like MS.
"The main problem with the previous, inadequate therapy was that it inhibited the entire immune system. However, we succeeded in finding new subtypes of cells that are specific for local inflammation and destruction in MS. They might therefore be selectively inactivated,” he added.
The fact that phagocytes from the blood and the brain play a role in MS has already long been known, but has been unclear up to now precisely which subtypes are involved. After years of research work, the scientists have now identified these subtypes in an animal model of MS.
Using the latest high-resolution single-cell methods, the researchers succeeded in mapping the complex composition of cells located at the focus of inflammation, the so-called inflammation infiltrate. This enabled them to create a new immune cell atlas.
The single-cell analyses used by the researchers are new and can be used in medicine for studying individual cells from tissues. The researchers see them as having enormous potential. "These methods allow us to paint an entirely new cellular picture of very complex tissues like the brain," said Dr. Dominic Gruen, one of the pioneers of this technique and research group leader at the Max Planck Institute of Immunobiology and Epigenetics in Freiburg, which participated in the study.
The first author of the study, Marta Joana Costa Jordao, doctoral candidate at the Institute of Neuropathology of the Medical Center at the University of Freiburg, also managed to demonstrate that different phagocytes in the brain remain chronically activated in the course of the disease. It was previously assumed that they were quickly renewed by circulating blood cells. "This permanent activation of the immune cells could explain why the brain of an MS patient is chronically attacked over the course of years," said Costa Jordao.