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

Abstract:

ObjectiveTo 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lymphocytes(CTLs) ,and provide  theoretical basis for the preparation of vaccine against influenza virus. MethodsMice were randomly divided into 3 groups：heterosubtypic immune group(immunized with recombinant virus  vaccine  rLH5 ), homosubtypic 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Ⅰ among 3 groups were compared, levels of IFNγ and T cells in  3 groups were studied.  ResultsAt 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 , mRNA expression of NotchDll1 and MHCⅠ in heterosubtypic immune  group were both higher than those in homosubtypic 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γ and 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).  ConclusionNotchDll1 and MHCⅠ in mice PAM may play active roles by promoting CTL differentiation during heterosubtypic immune  against influenza virus.