A new study sheds light on a mechanism within the body that helps limit the spread of salmonella, which explains the difference in the severity of infection between patients and opens the way for the development of treatments aimed at boosting immunity.
Salmonella bacteria are among the most common causes of food poisoning, usually transmitted through the consumption of raw or undercooked meat, poultry, and unpasteurized dairy products. It can also be transmitted from some pets. In most cases, the infection causes gastrointestinal symptoms such as vomiting and diarrhea, but it can sometimes develop into serious, systemic infections, such as typhoid fever.
This variation in the severity of the infection prompted researcher Kwook Kim from the University of Illinois at Chicago (UIC) and his team to investigate why some infections remain confined to the intestines, while others develop into life-threatening conditions.
The results of the study, published in the Journal of Experimental Medicine, showed that immune cells located in an organ known as the mesentery play a key role in limiting the spread of bacteria or, in some cases, allowing the infection to worsen.
The mesentery is a spiral-shaped organ about 1.8 meters long, located in the back of the abdominal cavity. It connects the intestines to other organs such as the liver, spleen, and pancreas, and contains a network of blood vessels, lymphatic vessels, and nerves.
Kim, a professor of pharmacology and regenerative medicine at the medical school, said that the precise function of the mesentery is still not fully understood, despite its anatomical connection to the small and large intestines. Researchers believe it provides structural support to internal organs and is involved in regulating the immune system.
The study focused on two types of immune cells within the mesentery: phagocytic cells, which are responsible for eliminating germs and damaged cells, and monocytes, which travel through the bloodstream to sites of infection when needed.
During experiments conducted on mice, researchers discovered that cooperation between these two types of cells helps prevent the spread of salmonella outside the intestines.
The results also showed that when phagocytic cells were removed from the mesentery during injury, large numbers of monocytes rushed into the organ, indicating that phagocytic cells regulate their entry, maintaining a balance of the immune response, because an increase in the number of immune cells could lead to damage to healthy tissues.
Kim believes that understanding the relationship between phagocytic cells and monocytes in the mesentery may open the door to developing new treatments that target the regulation of the immune system, helping to treat gastrointestinal infections and reduce the complications of salmonella infection.
