Abstract:Objective The aim of this study was to establish an influenza A virus-induced inflammation model inmice to analyze the pathogenicity of influenza A virus. Methods Forty-four 5-week old SPF healthy female BALB/ c micewere used in this study. A/ swine/ Jiangsu/ C1/08 (H9N2) (H9C1), A/ swine/ Shandong/731/2009 (SD731) and A/Puerto Rico/8/34 ( H1N1) ( PR8) influenza viruses were administered by intranasal instillation to BALB/ c mice,inoculated in a dose of 50 μL 1 × 106 TCID50, respectively, 11 mice in each group. The changes of body weight, clinicalsigns and death of the mice were observed every 24 hours from 1 to 14 dpi (days post inoculation). Blood and lung sampleswere taken for virus titer and inflammation detection. Results Compared with the PBS control group, SD731 and PR8virus infected mice showed a strong inflammation, and the mortality rate of SD731 virus infected BALB/ c mice was 80%and that of the PR8 virus infection was 100%. H9C1 virus infection caused a mild inflammatory response compared toSD731 and PR8 virus infection, and no significant weight loss and no death from 1 to 14 dpi. Conclusions In this study,the successfully established mouse model of influenza A virus-infected inflammation provides a strategy for the study of thepathogenesis of influenza virus, and a useful working basis for research of the pathogenesis, drug development, and vaccine evaluation of this disease.