When pathogens enter our body, cells of the immune system (so-called B and T cells) recognize the intruders and start to attack them. In order to prevent an over-the-top immune reaction, a different type of cells interferes in a regulatory way (so-called regulatory T cells). As a consequence, the different types of immune cells are accurately balanced, which guarantees a correct functionality of the immune system. However, there are always some cells that mix up foreign molecules and structures of the own body. If the body and the regulatory immune cells fail to completely sort out those self-reactive cells, an autoimmune disease arises, in which the immune system attacks parts of the own body.

To develop efficient treatments of both autoimmune diseases and acute infections, it is essential to understand the exact mechanisms of the immune response and its regulation. Therefore, the research group “Immune Regulation” investigates the basics of immune responses and autoimmunity at different mucosa as well as the influence of infections on the immune balance. The scientists use a mouse model to analyze these complex issues in the case of acute and chronic inflammatory diseases of the lung, the gut and the pancreas. Additionally, the researchers investigate the influence of immune responses induced by viral and bacterial infections on the progression of autoimmune diseases in the mouse model. For that, infections are provoked by the flu virus (Influenza A) or the bacterium Listeria monozytogenes, which is present in contaminated food.

An acute infection for example with the Influenza virus weakens the body and, by that, increases the chance of a secondary severe infection by a different pathogen. A previous flu leads to a higher mortality in case of a second infection. Researchers investigate the exact molecular and cellular mechanisms of such a super infection on the basis of the mouse model by a combined infection with both the Influenza A virus and the bacterium Streptococcus pneumonia that causes pneumonia, meningitis and sepsis (blood poisoning).