IL17A and infection: In contrast, the lungs infected with the highly virulent M. bovis strain 04–303 showed an increase in the percentage of CD11B+ Ly6G+ neutrophils on Days 14 and 21, with the latter being associated with extensive pulmonary necrosis, and the number of IL-17A+ neutrophils was maintained during the whole course of infection, with a slight increase in the days related with pulmonary necrosis (Fig 3C).