Reduced pulmonary injury caused by crossing NY1DD to Rag1^−/− mice is reversed by the adoptive transfer of NKT cells. (A) Representative flow cytometry plots of CD3⁺ lymphocytes in blood and lungs of C57BL/6 and NY1DD × Rag1^−/− animals. (B-C) Representative images of H&E-stained cells in C57BL/6 and NY1DD × Rag1^−/− animals. Scale bar represents 200 μm. (D) Histopathologic scores (0-8, see Methods) by analysis of H&E-stained mouse lungs. (E-F) NY1DD × Rag1^−/− animals have decreased vascular permeability and increased arterial oxygen saturation compared with NY1DD mice. The adoptive transfer of 10⁶ NKT cells significantly increased vascular permeability and decreased arterial oxygen saturation to near NY1DD baseline levels. (G) NY1DD × Rag1^−/− mice have significantly improved breathing (increased tidal volume and decreased frequency of breathing) compared with NY1DD mice. The adoptive transfer of 10⁶ NKT cells decreased tidal volume and increased frequency of breathing to near NY1DD baseline levels. Data were analyzed by one-way ANOVA with Neuman-Keuls posttesting. Histologic grading was analyzed with a nonparametric Kruskal-Wallis test with Dunn posttesting (*P < .05). SO₂ indicates arterial oxygen saturation; FOB, frequency of breathing; and TV, tidal volume.