Despite harboring more bacteria in the lungs throughout the infection, similar proportions of macrophages are present in the lungs of IL-1β and IL-1R deficient mice until 28 days post-inoculation when a higher proportion of CD11b+F4/80+ macrophages were recovered from the lungs of IL-1β and IL-1R deficient mice (Figure 3D) positively correlated with CFUs (r2 = 0.445, 0.842 respectively). This evidence concerns the gene IL1B and infection.