title: Immunization by influenza virus-like particles protects aged mice against lethal influenza virus challenge.
abstract: Influenza virus-like particles (VLPs) were produced in Sf9 insect cells by co-expressing the matrix protein M1 and the surface glycoproteins hemagglutinin (HA) and neuraminidase (NA) using the recombinant baculovirus expression system. The VLPs were morphologically similar to influenza virions. Both HA and NA proteins were incorporated into VLPs and these proteins retained their functional activities. Further, influenza VLPs but not inactivated influenza viruses (IIV) stimulated secretion of inflammatory cytokines from mouse bone marrow-derived dendritic cells (BMDC). Immunogenicity of influenza VLPs and their protective efficacies against lethal influenza virus challenge were evaluated in young and aged mice. Immunization with influenza VLPs induced strong antibody responses against HA that inhibited hemagglutination by influenza virus, similar to IIV vaccines. Compared to young mice, antibody responses in aged mice immunized with a low dose of either influenza VLPs or IIV vaccines exhibited markedly reduced avidity for HA. However, immunization of aged mice with a high dose of influenza VLPs induced antibody responses with high avidity similar to those in young mice. Furthermore, all vaccinated animals survived a lethal challenge by a mouse-adapted influenza virus (A/PR/8/34), indicating that influenza VLPs are highly efficacious for protection against influenza virus infection in both young and aged mice.
authors.affiliation: National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, People's Republic of China.
authors.forename: Zhiyuan
authors.initials: Z
authors.lastname: Wen
authors.forename: Ling
authors.initials: L
authors.lastname: Ye
authors.forename: Yulong
authors.initials: Y
authors.lastname: Gao
authors.forename: Lei
authors.initials: L
authors.lastname: Pan
authors.forename: Ke
authors.initials: K
authors.lastname: Dong
authors.forename: Zhigao
authors.initials: Z
authors.lastname: Bu
authors.forename: Richard W
authors.initials: RW
authors.lastname: Compans
authors.forename: Chinglai
authors.initials: C
authors.lastname: Yang
mesh_terms: D000367:Age Factors; D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology; D002460:Cell Line; D002478:Cells, Cultured; D016207:Cytokines / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology / Q000821:virology; D005260:Female; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D006801:Humans; D007114:Immunization; D053118:Influenza A Virus, H1N1 Subtype / Q000235:genetics / Q000276:immunology*; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D007251:Influenza, Human / Q000276:immunology* / Q000517:prevention & control* / Q000821:virology; D051379:Mice; D008807:Mice, Inbred BALB C; D009439:Neuraminidase / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D014764:Viral Proteins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D014771:Virion / Q000235:genetics / Q000276:immunology* / Q000378:metabolism
chemical_list: D000914:Antibodies, Viral; D016207:Cytokines; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D007252:Influenza Vaccines; D014764:Viral Proteins; C109963:hemagglutinin, avian influenza A virus; C487630:NA protein, influenza A virus; D009439:Neuraminidase