Figure 7.
Development of ILD in K14Cre;fl/fl mice is dependent on their autoreactive T cells, whereas skin and esophageal fibrosis is not. (A) Representative H&E and Masson-Trichrome staining of the lungs of recipient Rag1−/− mice to which 106 NK1.1−CD3+ T cells from fl/fl mice or K14Cre;fl/fl mice were transferred 2 (left) and 6 (right) mo before. Bars, 200 µm. (Right) Collagen contents of the total left lung from the recipient mice (2 mo after transfer) were measured by hydroxyproline assay. n = 4–7 mice per group. (B) Immunofluorescence with anti-CD3 antibody and DAPI was performed using the lungs of mice under the same conditions (2 mo after transfer). White, dashed lines indicate the bronchi. Bar, 200 µm. (C) Histological evaluation of inflammatory cell infiltration to various internal organs of recipient Rag1−/− mice 6 mo after transfer. (D) H&E and Masson-Trichrome staining of the back skin of 3-mo-old Rag1−/−;K14Cre;fl/fl and Rag1−/−;fl/fl mice. Double-headed arrows represent dermal thickness. Bars, 200 µm. (E, left) Dermal thickness was evaluated at the age of 3 mo in each group of mice. (Right) Hydroxyproline contents of the back skin were compared between these two groups of mice. (F, top) Masson-Trichrome staining of the lower esophagus of 3-mo-old Rag1−/−;K14Cre;fl/fl and Rag1−/−;fl/fl mice. Bars, 500 µm. (Bottom) Higher magnification images of the regions indicated by squares in the top panels. Bars, 200 µm. (G, left) Lamina propria thickness was evaluated at the age of 3 mo in each group of mice. (Right) Hydroxyproline contents of the lower esophagus were compared between these two groups of mice. n = 4 mice per group, unless otherwise indicated. Data in graphs are shown as mean ± SEM. *, P < 0.05 by two-tailed Mann-Whitney U test. For histological analyses, representative images of three independent experiments are shown. Results of other experiments are from representative experiments that have been repeated twice in different pairs of mice yielding similar results. AU, arbitrary units.