Type 2 cytokines IL-4 and IL-5 reduce severe outcomes from Clostridiodes difficile infection.

Clostridiodes difficile infection (CDI) is the leading cause of hospital-acquired gastrointestinal infections in the U.S. While the immune response to C. difficile is not well understood, it has been shown that severe disease is accompanied by high levels of infiltrating immune cells and pro-inflammatory cytokine production. This study tests the roles of two type 2 cytokines, IL-4 and IL-5, in mediating protection in a murine model of disease. Administration of IL-5 protected from mortality due to CDI, and both IL-4 and IL-5 were protective against severe disease symptoms. Together, the results from this study increase our understanding of how type 2 immune signaling processes are protective from severe C. difficile infection.