Salmonella enterica serovar TyphimuriumWIKIMEDIA, CDCSome immune responses are known to backfire. Autoimmunity is a well-documented case of this phenomenon. Now, researchers show that the pathogenic bacterium Salmonella enterica serovar Typhimurium can exploit a standard immune response to promote its own growth.
In a study published today (February 6) in Immunity, a team led by Manuela Raffatellu from the University of California, Irvine, reports having exposed mice with and without an immune signal molecule interleukin 22 (IL-22) to Salmonella infection. The researchers found that mice lacking IL-22 could combat the infection. But normal mice with IL-22 did not fare as well. It turns out that IL-22 enabled the invading Salmonella to establish itself by outmanoeuvring the competition: the commensal bacterium E. coli.
“[This study] takes several counterintuitive observations in the field and connects them to a coherent picture—a daring ‘Battle of the Bugs,’” said microbiologist Sebastian Winter, from the UT Southwestern Medical Center in Dallas, Texas, who was not involved in the work.
Immune cells produce IL-22 ...
