Pre-existing immunity abrogates the formation of necrotic granulomas. (A–C) d98 after CD infection (n = 5 per group). (A) Representative histology images of lung sections. Scale bar: 1 mm. (B) PCA of pathology scores. (C) Mtb lung burden in primary, BCG, and CoMtb groups. (D–L) d35 after ULD infection (n= 10 primary, 5 CoMtb). (D) Representative confocal microscopy images demonstrating preserved alveolar integrity in non-necrotic primary and CoMtb lesions. Scale bar: 500 μm; zoom: 50 μm. (E) Representative confocal microscopy images depicting major cell populations within lesions. Scale bar: 500 μm; zoom: 50 μm. (F) Percent of mice with necrotic lesions, covers two independent experiments. (G) Heatmap showing cellular composition of clustered microenvironments. (H) Representative map showing 50 µm neighborhoods, color-coded microenvironment. Scale bar: 500 μm. (I) Percent area of lesion comprised by each microenvironment. Uninvolved regions (gray) not included. (J) Percent of lesion comprised by necrotic region (pink). (K) Ratio of lymphoid (blue and green) to myeloid (yellow, orange, and pink) predominant regions. (L) Relative density of PPD signal per 50 µm² neighborhood. Single-group comparisons by Mann–Whitney U test. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001, and ns, P ≥ 0.05. Error bars (F) reflect 95% confidence intervals. Points represent individual mice or lesions from individual mice. Data are representative of one (A–C) or two (D–L) independent experiments with at least four mice per group. See also Fig. S1. PCoA, principal coordinate analysis