Figure 5.

Macroscopic (A), microscopic (B) lesion of lung and macroscopic lung lesion scores (C), microscopic lung lesion scores (D) in infected mice by recombinant Mycobacterium smegmatis. C57BL/6 mice (n = 3 per group) were treated intraperitoneally with 2 × 10⁶ rMS (Rv0888NS/MS, D438A/MS, and H481N/MS). Control mice were treated with PBS and pMV262/MS. Co-injection of histone inhibitor [polysialic acid (PLA)], caspase-3 inhibitor (Z-DEVD-FMK), and myeloperoxidase (MPO) inhibitor with Rv0888NS/MS was carried out in the mice. After 48 h, the left lung was removed, the macroscopic lesions were photographically recorded and analyzed with HE staining. Images are representative of one of three independent experiments with three mice per group. (A) PBS and pMV262/MS: no pathological changes; Rv0888NS/MS: severe hemorrhage; H481N/MS: mild hemorrhage; D438A: severe hemorrhage; PLA: widespread petechial hemorrhage; Z-DEVD-FMK: small range of petechial hemorrhage; and MPO inhibitor: slight hemorrhage (blue arrow). (B) PBS and pMV262/MS: no pathological changes; Rv0888NS/MS: multiple inflammatory cells infiltration (blue arrow) and bronchiole cavity hemorrhage (black arrow); H481N/MS: small amount of inflammatory cell infiltration of around the local small vessel (blue arrow); D438A: hemorrhage of the partial alveolar wall and around the small vein (black arrow); PLA: widespread inflammatory cells infiltration around the bronchiole and small vessel (blue arrow); Z-DEVD-FMK: small amount of inflammatory cells infiltration around the bronchiole (blue arrow); and MPO inhibitor: no pathological changes. Scale bars = 100 µm. (C,D) One-way ANOVA followed by Bonferroni’s multiple comparison post hoc test, *P < 0.05, **P < 0.01, ***P < 0.001, ns, non-significant.