IL-17A blockade prevents early post-transplant airway lesions in fully allogeneic grafts.

Fully allogeneic C57BL/6 tracheas were heterotopically grafted into control or anti-IL17 treated BALB/C recipients and harvested after 5 days. A, pathologic score. B, histologic analysis of allografts harvested from control and anti-IL17 treated recipients, respectively. Masson’s trichrome staining of a whole section (magnification x200). The black arrow shows the basal membrane thickening and the black arrowhead identifies epithelial flattening. The empty arrow shows the normal basal membrane and the empty arrowhead identifies the pseudostratified respiratory epithelium. C, absolute neutrophil count after specific Ly-6G immunostaining. D, IL-6 mRNA. E, HSP 70 mRNA. F, CK14⁺ basal cell count after specific immunostaining. The bars represent the mean ± SEM of 10 organs in each group. Data are pooled from two independent experiments. *, p < 0,05; **, p < 0,005 and ***, p < 0,001.