miR-155 shRNA lentiviral vector delivery attenuates airway inflammation after OVA challenge. (A) Differential cell counts for Mac, Eos, Lymph and Neu were calculated from cytospin preparations of bronchoalveolar lavage fluid collected 24 h after the last OVA challenge. (B) Histopathological sections of lungs collected 24 h after the last OVA challenge, and stained with hematoxylin and eosin (magnification, ×200). n=5 mice/group. *P<0.01 vs. the saline group; #P<0.05, ##P<0.01 and ###P<0.001 vs. Mock group. Mac, macrophages; Eos, eosinophils; Lymph, lymphocytes; Neu, neutrophils; OVA, ovalbumin; miR-155, microRNA-155; shRNA, short hairpin RNA.