Final answer:
TH17 cells are a subtype of helper T cells that are involved in defending the body against chronic mucocutaneous infections.
Step-by-step explanation:
TH17 cells are a subtype of helper T cells that play a role in the immune system's defense against chronic mucocutaneous infections. These cells produce specific cytokines that help protect the body from such infections. Patients who lack sufficient TH17 cells in the mucosa may be more susceptible to bacteremia and gastrointestinal infections.