Fig. 8: N protein induces lung injury in mice by activating NLRP3 inflammasome.

a–c C57BL/6 genetic background mice were tail vein-injected with 300 μl containing 5 × 10¹¹ vg of AAV-Lung-EGFP (n = 10) or AAV-Lung-N (n = 16) for 2 weeks and then treated with MCC950 (50 mg/kg) by intraperitoneal injection for AAV-Lung-EGFP (n = 5) or AAV-Lung-N (n = 8) mice. Serum was collected at 3 weeks for each group from the orbit. IL-1β (a), IL-6 (b), or IL-18 (c) in the sera was measured by ELISA. Points represent the value of each serum samples. d–f At 3 weeks, mice were killed and the lungs were collected. Histoimmunofluorescence analysis of IL-1β (d, red) or IL-6 (e, red) in the lung after AAV-CT or AAV-N infection. Scale bar is 200 μm (10×) or 50 μm (40×). Histopathology analysis of lung after AAV-CT or AAV-N infection (f). Red arrows indicated the infiltrated inflammatory cells. Scale bar is 200 μm (10×) or 50 μm (40×). g After 4 weeks, pretreated AAV-Lung-N mice (n = 7) with DMSO, pretreated AAV-Lung-N (n = 7) mice with MCC950, or pretreated AAV-Lung-EGFP (n = 5) with MCC950. After 30 min, mock group (n = 7), AAV-Lung-EGFP group (n = 5), AAV-Lung-N (n = 7) group, and another AAV-Lung-N (n = 7) group were treated with LPS (30 mg/kg) by intraperitoneal injection. Another mock group (n = 3) was intraperitoneally injected with PBS. The mice survival rates were evaluated every 2 h post treatment. Mock means inject the same dose of PBS as other groups (a–h). Data are representative of two independent experiments and one representative is shown. Error bars indicate SD of each serum samples, *P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001, two-tailed Student’s t-test (a–c). One-way ANOVA analysis (g). Source data are provided as a Source Data file.