Intestinal inflammation: immune cells protect nerve cells after infection
New findings on the functions of the gut-brain axis
P. Rosenstiel, IKMB Uni Kiel
The human gastrointestinal tract is permeated by nerve cells, which form a separate enteric nervous system. This controls digestion largely independently, for example by regulating the gastrointestinal motility. Previous studies have shown that the immune system in the gut also plays an important role. For example, specific immune cells regulate the activity of the nerve cells in healthy individuals. These interactions between nerve and immune cells are disrupted by diseases such as chronic inflammatory bowel disease or irritable bowel syndrome.
“The research shows that immune cells are also important for the survival of nerve cells in the case of infections," said Professor Philip Rosenstiel, member of the Steering Committee of the Cluster of Excellence "Precision Medicine in Chronic Inflammation" (PMI). Accordingly, specific immune cells recognize the infection and limit the damage to nerve cells. The specific cells are so-called macrophages in the gastrointestinal muscular layer. These are scavenger cells which detect and destroy pathogens. In the event of an infection, these macrophages initiate a protection program, in which they produce certain substances that ultimately protect the nerve cells. In turn, this protection program is apparently dependent on the microorganisms living in the intestine, the so-called microbiome. If these are absent, or if their balance is disturbed, the nerve cells are also no longer protected.
"The so-called gut-brain axis, through which the intestinal microbiome, the intestinal cells and the central nervous system cooperate, is an important topic for the future at the Cluster of Excellence PMI. Because the gut-brain axis could lead to new approaches for treating chronic inflammation, and also neurological diseases," said Professor Rosenstiel. "The mechanism, which has now been discovered in cooperation with Daniel Mucida and his team from New York, through which the immune system in the gut protects nerve cells in the event of an infection, is an important building block in the exploration of the gut-brain axis. We want to expand on this at the Cluster of Excellence, and increase our research efforts in this area in future," added Rosenstiel.