动物造模,甲型H1N1流感病毒 z-bio 2021-10-20 641

　　Objective To compare the ability of influenza A H1N1 influenza virus PR8 strain to infect old and young C57BL/6 mice to induce lung tissue CD8+ T cell specific immune response.

　　Method Use 490 PFU of PR8 virus to infect young (3-month-old) and old (24-month-old) C57BL/6 mice intranasally, and record their weight changes and deaths every day for 14 consecutive days. Isolate mouse lung tissue cells on the 8th day after infection, and use fluorescence-activated cell sorting (FACS) to detect the number and function of virus antigen-specific CD8+ T cells: MHC-I epitope peptide tetramer method (tetramer staining) stains influenza-specific CD8+ T cells, intracellular cytokine staining (intracellular cytokine staining, ICS) detects CD8+ T cells stimulated by influenza virus-specific peptides to secrete cytokine levels, including TNF-α, IFN- γ, IL-2 and the level of Granzyme B (Granzyme B) related to CD8+ T cell killing function.

　　Results After the same amount of PR8 influenza virus infects mice, the body weight of the old mice loses more, and the mortality rate is significantly higher than that of the young mice (P<0.01). On the other hand, the proportion of virus-specific CD8+ T cells induced by mice in the old group was significantly lower than that in the young group; at the same time, the activation of CD8+ T cells in the old group secreted cytokines TNF-α, IFN-γ and IL-2 The level was significantly lower than that of the young group; in addition, the level of granzyme B expression on CD8+T cells in the elderly group was also significantly lower than that of the young group.

　　Conclusion After PR8 influenza virus infects old and young C57BL/6 mice, the number and function of specific CD8+ T cells induced by the lung tissue of old mice are reduced. The results showed that compared with young mice, the lung tissue CD8+ T cell specific immune response function of old mice was impaired.