Please activate JavaScript!
Please install Adobe Flash Player, click here for download

uni'wissen 02-2012 ENG

System “It wasn’t even our intention to investigate the influence of nutrients on the immune system in the intestines” SystemSystem nutrients on the immune system in the intes- tines,” says the scientist. He only wanted to find out how lymphoid tissue inducer (LTi) cells de- velop and which molecules they control. Without Follicles, Infections Are Lethal LTi cells are a subfamily of the innate lym- phoid cells (ILC). After birth, LTi cells develop into various lyphoid cell clusters. They initially form cryptopatches that are located primarily in the small intestines. These accumulations of cells lie at the foot of the crypts, the indentations between two intestinal villi. Then the LTi cells at- tract other immune cells – B cells, which pro- duce antibodies. This makes the cryptopatch into a follicle: The mouse is now protected against enteropathogens and enterohemorrhagic bacteria. “They always cause lethal infections in mice without follicles,” explains Diefenbach. Even in healthy humans and animals, entero- pathogens sometimes cause severe, occasion- ally even lethal, diarrhea. Hemorrhagic bacteria such as EHEC (enterohemorrhagic E. coli) can also lead to lethal kidney damage. In the case of severe infections, the germs force themselves through the intestinal epitheli- um. This unicellular layer separates the intesti- nal mucous membrane from the intestines themselves. Once under the intestinal epitheli- um, the germs cause inflammations. “We want to prevent this,” says Diefenbach. However, it is still unclear how LTi cells, which belong to the innate 25