流感病毒感染小鼠肺巨噬细胞 Dll1和 MHC-Ⅰ表达研究

摘要

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-Ⅰ mRNA 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-Ⅰ mRNA 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-Ⅰ mRNA 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-Ⅰ mRNA 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.