Figure 3.

Infection of mice with the Δami1 mutant results in an elevated cytokine/chemokine response at 3-WPI, reduced specific myeloid and lymphoid cell populations in the lung and reduced lung pathology. C57BL/6 mice were infected intranasally with 100 CFU/mouse of the Mtb Δami1 mutant, complemented Δami1::ami1 and WT, H37Rv. (a) Cytokine and chemokine levels from whole lung homogenates of Mtb-infected mice were measured by ELISA at 3-WPI. (b) H&E histology staining of Mtb-infected lungs at 3-WPI. Inflammation was quantified as a measure of alveolar space (Magnification 10x). Percentage of lung alveolar airspaces were quantified from 4 deep cuts of H&E lung sections per mice (30 μm apart). Each data point represents an individual cut. (C) Mice were sacrificed at 3- and 6-WPI to measure mycobacterial burden by CFU enumeration in the lungs. Infected mice were sacrificed at 3-WPI and lungs were collected to measure the frequency and cell numbers of (d) myeloid and (e) lymphoid cell populations. Alveolar macrophages (Alv MΦ) = CD64⁺SiglecF⁺CD11c⁺, recruited interstitial macrophages (Rec MΦ) = CD64⁺CD11c⁻SiglecF⁺, CD103 dendritic cells (DC) = MHCII⁺CD11c⁺CD103⁺CD11b⁻, CD11b DC = MHCII⁺CD11c⁺CD103⁻CD11b⁺, neutrophils (Nφ) = LY6G⁺CD11b⁺, monocytes (MoM) = CD64⁺ CD11b⁺CD11c⁺, eosinophils (Eos) = CD64⁻SiglecF⁺CD11b⁺, B cells = CD19⁺CD3⁻, CD8⁺ T cells = CD3⁺CD4⁻CD8⁺, CD4⁺ T cells = CD3⁺CD4⁺CD8⁻, naïve T cells = CD62L⁺CD44⁺, memory T cells = CD62L⁺CD44⁻ effector T cells = CD62L⁻CD44⁺ (*P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001, ****P ≤ 0.0001, one-way ANOVA, n = 5–6). Data in panels A to E are representative of two independent experiments