Inflammatory cells infiltration into the lungs of the repeatedly antigen challenged mice. Lung tissue sections from mice at days 24 ((a) and (b)), 39 ((c) and (d)), and 54 ((e) and (f)) were studied by HE stain (×40). Inflammatory cells infiltration in the peripheral bronchial and subepithelium was observed from day 24 (b) and most seriously at day 54 (f) when mice were repeatedly challenged with OVA. The inflammation scores in peripheral bronchial and subepithelium were graded as mentioned in Section 2. The inflammation scores were significantly increased at day 39 and 54 in challenged mice when compared with sensitized mice (g). Each column represents the mean with SEM from 3 independent experiments. versus sensitized by Bonferroni/Dunn.