Fig. 3

Histological assessment of allografts. Sections were stained with HE. a Left transplanted lungs of AAT treated mice had a normal appearance with shape edge (no edema), healthy normal color and good compliance. Microscopically, the lung had only slight inflammation around vessels (rejection score A1-2) without distraction of lung parenchyma. b The controls had a reddish and edematous graft lung with bad compliance. The microscopic view showed strong inflammation, not only around vessels, but also in the parenchyma with distraction. c According to the classification of the international society of heart and lung transplantation, the differences of the acute rejection degree showed a significance between control group and AAT treated mice (control vs. AAT group: median 3 vs. 1, p = 0.0063, respectively). The p-value was calculated using two-tailed Mann–Whitney rank sum test. A p value of ≤ 0.05 was considered as statistically significant