Widely recognized as the face of\u00a0food poisoning, salmonella bacteria lurk in raw meat and poultry, on pets and in unpasteurized dairy products. If untreated, extreme cases can lead to full-body infections, like Typhoid fever.\u00a0<\/p>\n
UIC researcher\u00a0Kiwook Kim\u00a0asked\u00a0why some salmonella infections\u00a0remain\u00a0in the intestine, causing uncomfortable but nonfatal symptoms like vomiting and diarrhea, while others evolve into life-threatening infections.\u00a0<\/p>\n
In a new study, he\u00a0and his team of researchers\u00a0found that immune cells in a\u00a0portion\u00a0of the abdominal cavity, called the mesentery, play a critical role in suppressing – or\u00a0exacerbating\u00a0– salmonella infection.\u00a0The\u00a0study\u00a0appears in the\u00a0Journal of Experimental Medicine.\u00a0<\/p>\n
The mesentery is a\u00a06-foot, spiral-shaped\u00a0organ\u00a0curled up at the back of our abdominal cavity.\u00a0It’s\u00a0physically linked to the liver, spleen,\u00a0pancreas\u00a0and\u00a0intestines.\u00a0<\/p>\n
Although the gut mesentery anatomically connects to small and large intestines, its exact function is mysterious. Researchers believe it structurally supports our internal organs, with which it shares blood vessels, lymph nodes and nerves.”\u00a0<\/p>\n
Kiwook Kim,\u00a0professor of pharmacology and regenerative medicine, College of Medicine,\u00a0UIC<\/p>\n
Many types of immune cells\u00a0reside\u00a0within the gut mesentery. Macrophages,\u00a0immune cells\u00a0that live in tissues and are\u00a0everywhere in the body, find and remove germs and damaged or sick cells. Monocytes, similar in function, circulate in the bloodstream and attend to infected areas when needed.\u00a0<\/p>\n
In a series of tests conducted with mice, the researchers found that the interactions between macrophages and monocytes in the mesentery helped stop salmonella infection from spreading throughout the body.<\/p>\n
Further, the researchers noticed that when the mesentery’s resident macrophages were removed during salmonella infection, monocytes from the bloodstream flooded the organ. This suggested to the researchers that macrophages help mediate the presence monocytes in the mesentery, kind of like bouncers in a nightclub: Too many immune cells can damage the tissue, so only a regulated amount can pass through the velvet rope.\u00a0<\/p>\n
“Understanding the relationship between macrophages and monocytes in this portion of the gut can help us manipulate immune cells and develop therapies to treat gastrointestinal infections,” Kim said.<\/p>\n
Jiseon Kim, a postdoctoral research associate in the College of Medicine, is the study’s first author. Kiwook Kim is an affiliate of the University of Illinois Cancer Center.<\/p>\n
Source:<\/p>\n
University of Illinois Chicago<\/a><\/p>\n Journal reference:<\/p>\n