Figure 11. Protective effects of the recombinant L. plantarum on the appearance of the pathological damage in the lungs of virus-infected mice.

Lung samples from the groups of vaccinated mice were fixed with 4% paraformaldehyde on day 5 post-infection with mouse-adapted H9N2 AIVs (10 × LD₅₀) (a) and A/PR/8/34(H1N1) (0.5 × LD₅₀) (b). The sections were then stained with H&E (100×), and the figures show the results of a histopathological analysis from of at least three individual experiments. Open arrows show a vessel, and closed straight arrows show a bronchus. Scale bar, 200 μm. (c) The histopathological scores for lung sections from H9N2 or H1N1-infected mice. Lung sections were scored by an investigator blinded to the mouse identity for total lung inflammation (alveolitis and peribronchiolar inflammation) on a scale from 0 to 5. The results are presented as the means ± SEM of triplicate tests (n = 3 ~ 5 mice per group), and the significance of differences was analysed using a one-way ANOVA, assuming Gaussian distribution, followed by Dunnett’s post-test and are expressed relative to PBS, NC8-pSIP409 and NC8-pSIP409-NP-M1-Ctrlpep (*P  <  0.05, **P < 0.01, and ***P < 0.001).