IFNG and infection: Therefore, we examined if blocking IFN-γ hinders bacterial clearance in the KO mice following infection with S. aureus. In this context, we administered anti-mouse IFN-γ antibody (100 μg/mouse i.p.)to one group of the KO mice and a similar volume of isotype antibody to another group of mice 12 hours before infection with S. aureus. Blocking of IFN-γ in the KO mice increased the bacterial burden in the lungs and BALF suggesting that IFN-γ mediates bacterial clearance in the KO mice (Fig 5A and 5B).