流感病毒感染小鼠肺巨噬细胞Dll1和MHC-Ⅰ表达研究

Notch-Dll1 and MHC-Ⅰexpression in pulmonary alveolar macrophages of mice infected with influenza virus

目的探讨小鼠肺巨噬细胞Dll1及MHC-Ⅰ与细胞毒性T淋巴细胞(CTL)为主的细胞免疫应答的关系,为制备有效的新型抗流感病毒疫苗提供理论依据。方法将小鼠随机分为3组,异型免疫组(用rL-H5株重组二联活疫苗免疫)、同型免疫组(用A/H1N1流感病毒免疫)和未免疫感染组(用PBS代替疫苗),不同疫苗免疫小鼠后均感染A/H1N1型流感病毒,比较3组小鼠肺巨噬细胞Notch-Dll1及MHC-Ⅰ表达情况,并研究干扰素(IFN)-γ、T细胞水平变化。结果异型免疫组感染4 d和7 d后,肺巨噬细胞Notch-Dll1[分别为(0.01460±0.00125)和(0.01750±0.00196)]及MHC-ⅠmRNA表达水平[分别为(0.03050±0.0029)和(0.0495±0.0024)]显著高于感染前[分别为(0.00045±0.00004)和(0.0120±0.0018)],未免疫感染组感染4 d和7 d后Notch-Dll1[分别为(0.01010±0.00107)和(0.01320±0.00143)]和MHC-ⅠmRNA表达水平[分别为(0.0219±0.0024)和(0.0248±0.0022)]均高于感染前[分别为(0.00032±0.00007)和(0.0090±0.0013)];异型免疫组感染4 d和7 d,后Notch-Dll1和MHC-ⅠmRNA表达水平均高于同型免疫组[感染4 d和7 d后,Notch-Dll1分别为(0.00089±0.00018)和(0.00143±0.00096),MHC-ⅠmRNA分别为(0.0038±0.0008)和(0.0008±0.0002)及未免疫感染组,差异均具有统计学意义(均P<0.05)。感染后第7天,异型免疫组IFN-γ、CD8+T细胞的百分比含量为(3.31±0.34)%,高于同型免疫组和未免疫感染组[分别为(0.38±0.06)%和(1.58±0.27)%];感染后第5天,异型免疫组流感病毒量为[(6.26×105)±(3.7×105)]copies/μL,低于未免疫感染组[(6.85×107)±(2×107)]copies/μL,而高于同型免疫组(400±250)copies/μL(均P<0.05)。结论小鼠肺巨噬细胞Dll1及MHC-Ⅰ的表达可能在以CTL为主流感病毒异型交叉保护免疫应答反应中起重要作用。

Objective To study the relationship between Notch ligand Delta-like 1 （Dll1 ）,MHC class I molecule （MHC-Ⅰ）in mice pulmonary alveolar macrophages （PAM）and cellular immunity response based on cytotoxic T-lympho-cytes（CTLs）,and provide theoretical basis for the preparation of vaccine against influenza virus.Methods Mice were ran-domly divided into 3 groups：heterosubtypic immune group（immunized with recombinant virus vaccine rL-H5 ）,homosub-typic immune group （immunized with A/H1N1 influenza virus vaccine）,and viral infection group（immunized with PBS）. Mice immunized with different vaccines were all infected with A/H1N1 influenza virus.mRNA expression of Notch-Dll1 and MHC-Ⅰamong 3 groups were compared,levels of IFN-γand T cells in 3 groups were studied.Results At day 4,7 of post-infection,in heterosubtypic immune group,mRNA expression of Notch-Dll1 （ [0.01460 ± 0.00125 ]）,[0.01750±0.00196]）and MHC-Ⅰ （[0.03050±0.0029],[0.0495±0.0024]）were both higher than those before infection （[0.00045±0.00004],[0.0120±0.0018]）,in viral infection group,mRNA expression of Notch-Dll1 （[0.01010±0.00107],[0.01320 ±0.00143]）and MHC-Ⅰ （[0.0219 ±0.0024],[0.0248 ±0.0022]）were both higher than those before infection（[0.00032±0.00007],[0.0090±0.0013]）;At day 4,7 of post-infection ,mR-NA expression of Notch-Dll1 and MHC-Ⅰ in heterosubtypic immune group were both higher than those in homo-subtypic immune group （Notch-Dll1 [0.00089 ±0.00018],[0.00143 ±0.00096];MHC-Ⅰ [0.0038 ±0.0008], [0.0008±0.0002 ]）and viral infection group,the difference was statistically significant（all P 〈0.05）.At day 7 of post-infection,the percentage of IFN-γand CD8＋T cells in heterosubtypic immune group was（3.31 ±0.34）% ,which was significantly higher than homosubtypic immune group （[0.38±0.06]%）and viral infection group （[1.58±0.27]%）;At day 5 of post-infection ,viral load of heterosubtypic immune group （[6.26×105 ±3.7×105 ]copies/μL）was lower than that of viral infection group （[6.85×107 ±2×107 ]copies/μL）,but higher than that of homosubtypic immune group（[400 ±250 ]copies/μL ）（all P 〈0.05）.Conclusion Notch-Dll1 and MHC-Ⅰ in mice PAM may play active roles by pro-moting CTL differentiation during heterosubtypic immune against influenza virus.