Researchers track down antibodies responsible for MS
Autoimmune diseases establish themselves when antibodies designed to protect the human body against foreign invaders turn against their own cells and tissues. In multiple sclerosis (MS), antibodies begin to attack nerve cells which leads to a degeneration of the myelin fibres, the sheath that surrounds neurons. Very little is known about where these antibodies come from, but now scientists have identified a way to allocate antibodies to their source cells, thereby allowing a better tracking of these rogue molecules. The immune system in a healthy person defends the body robustly against invaders, such as bacteria and viruses. The system produces millions of antibodies that defend us against these pathogens, but in an autoimmune disease these antibodies no longer recognise their own cells, seeing them instead as foreign bodies which must be attacked. In multiple sclerosis, the antibodies cause inflammation in the central nervous system as cells attack myelin, a fatty substance that surrounds nerve fibres. Consequent degeneration and scarring of the myelin leads to an impaired functioning of neurological impulses from the brain. Those suffering from multiple sclerosis ('sclerosis' means 'hardening' in Greek), experience a number of symptoms including numbness and tingling in the fingers, blurred vision and loss of memory. Finding out where the aggressive antibodies that attack the myelin sheath originate is an important step in understanding multiple sclerosis. If, like other antibodies, the MS-related molecules originate in the blood or lymphatic organs such as the spleen, bone marrow or lymph nodes, then they would have to move through the blood to reach the liquid surrounding the nerve cells. At the Max-Planck Institutes of Neurobiology and Biochemistry and the University Hospital of Grobhadern in Munich, Germany, scientists have developed a method of tracking these antibodies back to their original cells. To do this, B cells were isolated from nerve cell liquid and the genetic code of the DNA region responsible for the production of antibodies was analysed. This allowed the calculation of the size and weight of the antibody fragments that were produced by each analysed B cell. Antibodies found in the nerve cell liquid were also analysed and both sets of data were compared. The results were conclusive: the antibodies found in nerve cell liquid are produced by the present B cells. A high level of genetic variability in certain areas of DNA showed that B cells in the liquid had already made contact with target structures in the nervous system. 'The next step is now the assembly of the fragments into complete antibodies, which should allow us to identify their target structures in the nervous system. An additional highlight of this new procedure is the fact that it's not restricted to multiple sclerosis analyses,' says Klaus Dornmair, the supervisor of the study. The ultimate goal of the research is to identify target structures which could lead to the removal of the most destructive antibodies leading to a lessening of the symptoms of multiple sclerosis.
Countries
Germany