Tuesday February 22, 2022 – Author:
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The causes of multiple sclerosis are still being researched. A twin study provides new insights. Certain abnormalities in the immune system activate the nerve-damaging T cells.
After the causes of multiple sclerosis is still being researched. Scientists from the University of Zurich and the LMU Klinikum Munich have examined the immune system of identical twin pairs in order to break down the influence of environmental influences and genetics on multiple sclerosis. In doing so, they made a discovery.
Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system. It is the most common cause of neurological impairment in young adults. In MS, your own immune system attacks your brain and spinal cord. This usually leads to progressive neurological dysfunctions such as visual disturbances, sensory disturbances, motor deficits and cognitive limitations.
61 pairs of twins studied, one twin suffering from MS
Studies in recent years have shown that genetic risk variants are inextricably linked to the development of MS. “Through our study, we were able to show that approximately half of the composition of our immune system is determined by genetics,” says Dr. Florian Ingelfinger, PhD student at the Institute for Experimental Immunology at the University of Zurich.
As part of the study, 61 identical – ie genetically identical – twin pairs were examined, of which one twin suffers from MS and the other twin is healthy. “Although the healthy twins also carry a maximum familial risk for developing MS, they did not show any clinical signs of MS,” says Dr. Lisa Ann Gerdes, neuroimmunologist at the Institute for Clinical Neuroimmunology at the LMU Klinikum and head of the MS Twin Study.
Specific immune profile leads to activation of T cells
The researchers’ central question: “How can the immune system of two genetically identical individuals lead to this clear inflammatory reaction and massive nerve damage in just one case, while the other twin is not damaged at all,” explains Prof. Becher from the University’s Institute for Experimental Immunology Zurich.
When comparing the immune profiles of the twin pairs, the researchers found the greatest differences in so-called cytokine receptors, i.e. the way in which immune cells communicate with each other. Increased sensitivity to certain cytokines leads to greater activation of T cells in the blood of patients with multiple sclerosis. These are particularly capable of migrating into the patient’s central nervous system and causing damage there.
New insights into the causes of multiple sclerosis
The identified cells showed characteristics of recently activated cells that were in the process of developing into fully functional T cells. “We may have discovered the cellular big bang of MS here – progenitor cells from which disease-causing T cells arise,” explains Prof. Becher in a press release. The study, which provides new insights into the causes of multiple sclerosis, was published in the journal Nature.