The effect of OVA challenge on airway inflammation and AHR at the later stage of respiratory syncytial virus infection in mice

doi:10.13431/j.cnki.immunol.j.20170050

Abstract：The present study was performed to investigate the effect of recurrent allergen challenge on airway inflammation and airway hyperresponsiveness (AHR) after respiratory syncytial virus (RSV) infection.Six to eight weeks old female Balb/c mice were randomly divided into mock group,RSV group,OVA group,and R+O group.The counts of total cells and different types of leukocytes in bronchoalveolar lavage fluid (BALF) were measured for determination of airway inflammation,as well as the infiltration of inflammatory cells in lung tissues by hematoxylin-eosin staining.AHR was measured by whole-body plethysmography.ELISA was used to detect the levels of interleukin-4 (IL-4),interleukin-5 (IL-5),C-X-C motif chemokine ligand 10 (CXCL10),C-C motif chemokine ligand 5 (CCLS),C-C motif chemokine ligand 20 (CCL20) in BALF.Compared with mock group,the number of total inflammatory cells,macrophages,neutrophils,eosinophils and CXCL10 in BALF were increased in RSV group,OVA group and R + O group,while R + O group has a more remarkable increase among the three treatment groups(P＜0.05).Similar results were observed in AHR and histopathological score of lung tissue.IL-4 and IL-5 were dramatically increased in each treatment group(P＜0.05),but there was no statistical significance among these groups.Besides,CCL5 and CCL20 showed no differences among the four groups.In conclusion,the increased CXCL10 may accelerate the infiltration of macrophages,neutrophils and eosinophils,contributing to the aggravation of airway inflammation and AHR after OVA challenge at the later stage of RSV infection.