Airway eosinophils in the B6-E2IL5tg mouse model are constitutively degranulating. (A) Immunoreactive mEPX was detected in BAL fluid from virus-naïve B6-E2IL5tg and PVM-infected B6-E2IL5tg mice only; n = 4 to 8 mice per group; ***P < .0001 vs all other conditions (2-way ANOVA); there is no statistically significant difference between the mEPX levels detected from virus naïve and virus-infected B6-E2IL5tg mice. (B) Ribonuclease (RNase) activity was detected in BAL fluid from virus-naïve and B6-E2IL5tg and PVM-infected B6-E2IL5tg mice only; n = 4 to 8 mice per group; ***P < .0001 vs all other conditions; there is no statistically significant difference between the RNase activities detected from virus naïve and virus-infected B6-E2IL5tg mice. (Inset) Western blot of BAL fluid from PVM-infected mice probed with rabbit polyclonal antisera against mEars. In both (A) and (B), dotted lines indicate lower limits of detection of each assay.