动物造模 z-bio 2022-01-17 211

　　Objective: After highly pathogenic avian influenza infects mice, over-expressed inflammatory factors, i.e. inflammatory factor storm, are detected in the lungs. A high level of inflammatory response is more common in elderly infected patients. Influence of anti-infective immune response.

　　Methods: Aged mice (18-24 months old) were challenged with influenza virus H9N2 to establish an infection model of old mice. The control group was H9N2-infected adult mice (6-8 weeks). H9N2 infection was quantitatively analyzed respectively. The expression of inflammatory factors in the lung in situ and peripheral blood of aged mice was investigated, and in the acute phase of infection, the collected mouse lung tissue was prepared into slices and digested into single cell suspensions. Among them, lung tissue slices were used for Immunohistochemistry was used to quantitatively analyze the distribution of immune cells in situ; T cells were sorted from the cell suspension and counted by staining.

　　RESULTS: Compared with adult mice, aged mice infected with H9N2 virus had a significant weight loss and a survival rate of only 50%. However, compared with adult mice, inflammatory factors were rarely detected in lung tissue after infection. Inflammatory factor storm appeared in the lungs, and the inflammatory factor IL-6 and chemokine MCP-1 were abnormally highly expressed, and peaked on the 2nd day after infection (over 4000 pg/mL), which was 100-1000 times that of adult control mice. After infection with H9N2 virus in aged mice, compared with adult controls, their lung macrophages had a lower response, pulmonary neutrophils had a weaker migratory ability, and were more retained in the lungs within 3 to 7 days after infection. On the 7th day after H9N2 infection in aged mice, the number of CD8+ T cells in the lung decreased significantly, while the number and proportion of CD4+ T cells remained normal.

　　Conclusion: The inflammatory factor storm appeared in the lung tissue of aged mice infected with H9N2 virus. Although the types of cells involved in the anti-infection immune response were not significantly different from those of adult mice, the migration ability of immune cells was reduced, and the acquired cellular immunity involved in the response was also strong. significantly reduced.