IL17A and infection: Although infection by intracellular bacteria is predominantly cleared by Th1 immuneresponses, recent studies have described an emerging role for IL-17 in protectionagainst intracellular pathogens such as Listeria monocytogenes71, Mycoplasma pneumonia72, Legionella pneumophila73, 74, Salmonella typhimurium75, Chlamydia muridarum76, Francisella tularensis77, and Mycobacterium tuberculosis78.