Multiple sclerosis (MS) is the most common inflammatory disease of the central nervous system. It has been suspected for some time that bacteria in the natural intestinal flora may be responsible for triggering the disease in individuals genetically predisposed to it. Together with researchers from the Ludwig Maximilian University of Munich, the Max Planck Institute of Immunobiology and Epigenetics in Freiburg and the Universities of California (San Francisco) and Münster, Hartmut Wekerle and Gurumoorthy Krishnamoorthy from the Max Planck Institutes of Neurobiology and of Biochemistry in Martinsried have, for the first time, shown that intestinal flora from patients with MS can trigger an MS-like illness in an animal model.
n autoimmune diseases such as multiple sclerosis, errant immune cells attack the body's own cells in the brain and spinal cord. Attacks triggered by autoimmune T-cells damage the nerve cells and result in the destruction of the sheath that surrounds these cells. The cells die off, with the result that nerve impulses are no longer transmitted correctly.
Every person has T-cells with the potential to attack their own cells; however, these cells usually remain permanently dormant. In some people, however, the pathogenic potential of these cells is activated, resulting in MS. Scientists believe that activation is caused by a combination of genetic and environmental factors. "More than 200 genes that increase susceptibility to MS have now been identified," explains Hartmut Wekerle, Hertie Professor and Emeritus Director at the Max Planck Institute of Neurobiology, “but for MS to develop, there must be a trigger. To date, most research on triggers has looked at infectious diseases.” A few years ago, the neuroimmunologist, together with his colleagues Kerstin Berer and Gurumoorthy Krishnamoorthy who now leads a Research Group at the MPI of Biochemistry, determined that this trigger is likely to be found in the natural intestinal flora. Together with other colleagues, the researchers showed that intestinal microorganisms were able to activate T-cells in genetically modified autoimmune mice, causing the mice to develop brain lesions similar to those found in MS.