Fig. 5: GSDMD deficiency limits viral loads, epithelial cell death, and immunopathology.

Wildtype and Gsdmd^−/− mice were infected with 10⁴ PFU of HKx31 IAV. A Lung viral loads (pfu/lung) measured by a standard plaque assay. Data presented as the mean ± SD, with each data point representing an individual animal. n = 8 per group, pooled from two independent experiments. *p < 0.05, two-tailed unpaired Student’s t test. Relative concentrations of B LDH (OD; optical density) and C total protein in BAL fluids at day 3, quantified using colorimetric assays. Data presented as the relative mean ± SD, with each data point representing an individual animal. n = 11 or 12 per group, pooled from three independent experiments. *p < 0.05, two-tailed unpaired Student’s t test. D–G Lungs were formalin inflated and fixed on day 3 post-infection. D Histological analysis of H&E-stained lung tissue sections were performed and representative images at 10× magnification (scale bar = 100 μm) are shown. Lung sections were randomized and scored blind for E peribronchial inflammation (scale 0–5), F alveolitis (scale 0–5) and G epithelial damage (scale 0–4), as described in the Materials and methods. Data are presented as the mean ± SD, with each data point representing an individual animal. n = 8 per group, pooled from two independent experiments. *p < 0.05, **p < 0.01, ***p < 0.001, two-tailed unpaired Student’s t test. H, I TUNEL assay labeling of cell death in lung tissue sections. H Representative images at 10× magnification (scale bar = 100 μm). n = 8 per group, pooled from two independent experiments. I Quantification of TUNEL staining determined using ImageJ software. Data presented as the mean % positive pixel intensity per field of view (FOV) ± SD, with each data point representing an individual animal. **p < 0.01, two-tailed unpaired Student’s t test.