As every parent knows, babies are especially vulnerable to bacterial infections. A study suggests that the body deliberately controls this vulnerability, allowing healthy microbes to colonize the baby’s intestines, mouth, skin and lungs.
Understanding how this system works could lead to treatments for infections in newborns. This is what researcher Sing Sing Way tried to do.
This pediatrician specializing in infectious diseases at Cincinnati Children’s Hospital in Ohio in the United States compared the immune cells of young mice aged 6 days and adult mice. The mice had a higher concentration of red blood cells which expressed a protein called CD71. The researchers found that these cells could suppress the immune response by making an enzyme called arginase.
Antibodies capable of destroying CD71 were given to young mice to observe what would happen to the immune level. In the presence of the bacteria Listeria monocytogenes which can cause severe infections in babies, the mouse’s immune system defended itself properly. Problem, without these CD71 cells, the intestines of mice would become infected on contact with any normal intestinal bacteria.
The microbial ecosystem interacts with the immune system
The researchers also found that these CD71 cells were found in higher concentrations in the umbilical cord of mice than in cells of adult mice.
These results tend to show that the baby’s microbial ecosystem is in complete interaction with his immune system, which means that one cannot change without modifying the other.
Based on these findings, the researchers believe that by stimulating CD71, we could, for example, suppress the immune response of newborns to allow good bacteria to colonize his body. Conversely, we could stimulate the baby’s immune system by removing CD71 to allow for example vaccinate babiestoo weak to be.
