effect of influenza virus infection in a murine model of asthma

respiratory virus infection is a major cause of asthma exacerbation. however, the underlying mechanisms of  this exacerbation  are unknown. therefore,  to  determine  the mechanisms, we examined the effect of influenza infection in a murine model of asthma.mice were divided into four groups: the phosphate-buffered saline (pbs), house dust mite (hdm), influenza, and hdm/influenza groups. the influenza group and the hdm/influenza group were infected with influenza a virus. we measured airway resistance (penh value), examined the lung tissue for pathology, and analyzed the cells and cytokines in bronchoalveolar lavage fluid (balf) by elisa.at 50 mg/ml methacholine, the hdm/influenza group showed a significantly higher penh value than the pbs, hdm, and influenza groups. the number of neutrophils in balf was higher in the hdm/influenza group than in the hdm group. a significantly greater number of lymphocytes and macrophages were detected in the hdm/influenza group than in the hdm group. ifn-γ and il-1β levels were higher in the hdm/influenza group than in the hdm group. il-5 levels did not vary between the hdm and hdm/influenza groups, il-10 was significantly lower in the hdm/influenza than in the hdm group. chemokine (c-x-c motif) ligand 1 (cxcl1) and regulated upon activation, normal t cell expressed and secreted (rantes) were higher in the hdm/influenza group than in the hdm group.in a murine model of asthma, influenza-induced airway inflammation appeared to becaused by simultaneous activation of neutrophilic and eosinophilic inflammation.