甲型H1N1流感病毒感染年轻和老年C57BL/6小鼠 诱导肺组织CD8^(+)T细胞特异性免疫应答的比较研究  

Study of the immune responses mediated by specific CD8^(+)T cells to influenza A virus H1N1 in the lungs of young and aged C57BL/6 mice

作　　者：刘洋[1] 王超[1] 任晓楠[1] 李顺[1] 秦波音[1] 杨华[1] 周晓辉[1] LIU Yang;WANG Chao;REN Xiaonan;LI Shun;QIN Boyin;YANG Hua;ZHOU Xiaohui(Shanghai Public Health Clinical Center,Fudan University,Shanghai 201508,China)

机构地区：[1]复旦大学附属公共卫生临床中心,上海201508

出　　处：《中国实验动物学报》2021年第4期461-466,共6页Acta Laboratorium Animalis Scientia Sinica

基　　金：国家自然科学基金(81471397,31601908);国家重点研发计划(2016YFD0500208);国家十三五传染病重大专项(2017ZX10304402-001-012,2017ZX10304402-001-006);上海市公共卫生临床中心院内项目(KY-GW-2019-19,KY-GW-2021-05,KY-GW-2021-38)。

摘　　要：目的比较甲型H1N1流感病毒PR8毒株感染老年和年轻C57BL/6小鼠诱导肺组织CD8^(+)T细胞特异性免疫应答的能力。方法使用490 PFU的PR8病毒分别滴鼻感染年轻(3月龄)和老年(24月龄)C57BL/6小鼠,连续14 d每日记录其体重变化及死亡情况。在感染后第8天分离小鼠肺组织细胞,使用流式细胞术(fluorescence-activated cell sorting,FACS)技术检测病毒抗原特异性CD8^(+)T细胞数量及功能:MHC-I表位肽四聚体法(tetramer staining)染色流感特异性CD8^(+)T细胞,细胞内细胞因子染色法(intracellular cytokine staining,ICS)检测CD8^(+)T细胞经流感病毒特异性肽刺激后分泌细胞因子水平包括TNF-α、IFN-γ、IL-2以及与CD8^(+)T细胞杀伤功能有关的颗粒酶B(Granzyme B)的水平。结果相同量的PR8流感病毒感染小鼠后,老年小鼠体重下降更多,死亡率显著高于年轻小鼠(P<0.01)。另一方面,老年组小鼠诱生的病毒特异性CD8^(+)T细胞比例显著低于年轻组;同时,老年组CD8^(+)T细胞活化后分泌细胞因子TNF-α、IFN-γ、IL-2的水平显著低于年轻组;此外,老年组CD8^(+)T细胞表达granzyme B的水平同样显著低于年轻组。结论PR8流感病毒感染老年和年轻C57BL/6小鼠后,老年小鼠肺组织诱导产生的特异性CD8^(+)T细胞的数量减少且功能降低。结果表明:与年轻小鼠相比,老年小鼠肺组织CD8^(+)T细胞特异性免疫应答功能受损。Objective To compare the immune response of specific CD8^(+)T cells induced by H1N1 Influenza A virus PR8 strain in the lungs of young and aged C57BL/6 mice.Methods Young(3 months)and aged(24 months)mice were intranasally infected with 490 plaque-forming units of PR8,then 8 days later,they were euthanized and their lungs collected.Fluorescence-activated cell sorting was used to compare the number and functions of viral antigen-specific CD8^(+)T cells between the young and aged mice.Surface staining for the influenza virus MHC-I tetramer was performed to count the antigen-specific CD8^(+)T cells;and intracellular cytokine staining was used to quantify the cytokines secreted by CD8^(+)T cells in response to influenza-specific peptides,including tumor necrosis factor(TNF-α),interferon-γ,interleukin-2,and granzyme B,which are involved in killing by CD8^(+)T cells.Results The proportion of virus-specific CD8^(+)T cells in the aged mice was significantly lower than in the young mice.Moreover,the expression of interferon-γ,TNF-α,and interleukin-2 in activated CD8^(+)T cells from the aged mice was significantly lower than in the young mice.In addition,the level of granzyme B expression on CD8^(+)T cells in the aged mice was significantly lower.Conclusions The number of specific CD8^(+)T cells induced by PR8 influenza virus was lower,and their function was impaired in the lungs of aged C57BL/6 mice compared with young mice.This implies that the response by specific CD8^(+)T cells in the lungs of mice is impaired by aging.

关 键 词：甲型流感病毒 病毒特异性CD8^(+)T细胞 免疫应答 

分 类 号：Q95-33[生物学—动物学]