动物造模 z-bio 2022-10-20 515

　　Objective To establish a mouse model of chronic lymphocytic choriomeningitis virus LCMV-CL13 infection and analyze its possibility as a model for the study of high-frequency mutation of B cell receptor.

　　Methods C57BL/6N mice were inoculated via tail vein 2 × 106PFU dose of LCMV-CL13 virus. Samples were collected on the 10th, 20th, 30th, 40th, 50th, 60th and 70th days after infection. The viral load in tissues was detected by qPCR. The ratio of CD4+T, CD8+T, CD19+B cells in peripheral blood and B cells in spleen germinal center was analyzed by flow cytometry. The gene abundance and mutation rate in BCR V region were analyzed by sequencing in the immune group library.

　　Results 1 × 106copies/ μ L level virus replication; At the stage of infection, the percentage of CD4+T cells in the peripheral blood of mice gradually increased (13.15% ± 0.72%), the percentage of CD8+T cells first decreased (2.17% ± 0.40%) and then gradually recovered (6.65% ± 0.52%), the percentage of CD19+B cells and germinal center B cells increased to (40.32% ± 0.46%) and (10.03% ± 0.60%) respectively; Sequencing results showed that the use frequency of BCR heavy chain V gene decreased and the mutation rate increased significantly (P<0.05).

　　Conclusion LCMV-CL13 chronic infection mouse model was successfully established; This model can be used for the study of BCR mutation, which lays a foundation for the study of high-frequency mutation of B cells caused by chronic virus infection.