Young (7–9 week) and older (12–14 month) C57BL/6 mice were i.n. inhalant treated with ODE or saline daily for 3 weeks whereupon mice were euthanized, lavage fluid removed, pulmonary vasculature perfused, and lung cells dissociated and analyzed by flow cytometry. A, Depiction of gating strategy, which is detailed in the Methods section. Distribution of lung Ly6G+ neutrophils (B); alveolar CD11chiCD11blo and exudative CD11chi CD11bhi macrophages (C); and CD3+CD4+and CD3+CD8+ T lymphocytes and CD3−B220+ B lymphocytes (D) are shown as mean percentage with standard deviation bars of CD45+ leukocytes. E, Ratio of CD4:CD8 cells demonstrating that CD4 lymphocytes predominant the T cell response in young mice and CD8 lymphocytes predominant in older mice. N=5 mice/group. Statistically significant (*p<0.05) vs. respective saline. #p<0.05 denotes statistical significance between young/older mice.