Baculovirus-produced influenza virus-like particles in mammalian cells protect mice from lethal influenza challenge

Viral Immunol. 2011 Aug;24(4):311-9. doi: 10.1089/vim.2011.0016.

Abstract

Influenza virus-like particles (VLPs) are effective vaccines against influenza infection, which can be produced either in insect cells by recombinant baculovirus (BV) infection or in mammalian cells by DNA plasmid transfection. However, VLPs produced from baculovirus/insect cells are difficult to purify due to baculovirus contamination; VLPs produced by plasmid transfection are limited by scale-up capability. In this study, a BacMam BV, in which three CMV-promoters drive the hemagglutinin, neuraminidase, and matrix of influenza virus was constructed. This baculovirus can deliver these genes into mammalian cells/hosts and subsequently influenza VLPs can be produced and secreted from transduced cells. Transduction conditions were optimized and influenza VLPs were purified from transduced 293T cells. Mice were vaccinated with BV transduction-produced VLPs, plasmid transfection-produced VLPs, and BacMam BV. Two vaccinations of each vaccine induced high hemagglutination-inhibition (HAI) titers and prevented influenza virus infection. In contrast, following a single vaccination, all mice vaccinated with each vaccine had significantly lower lung viral titers compared to unvaccinated mice. Remarkably, mice vaccinated with a single dose of BV transduction-produced VLPs survived challenge, whereas mice vaccinated with one dose of BacMam BV- or plasmid transfection-produced VLPs had 60-80% survival. This finding is particularly significant for producing easily purified VLPs. The BacMam system is an alternative strategy for VLP production, which is easy to scale up and purify. Besides, BacMam BV can be used as a gene delivery vector to produce VLPs in vivo, to stimulate immune responses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Viral / blood
  • Baculoviridae / genetics
  • Cell Line
  • Disease Models, Animal
  • Female
  • Genetic Vectors
  • Hemagglutination Inhibition Tests
  • Humans
  • Immunization, Secondary / methods
  • Influenza Vaccines / administration & dosage
  • Influenza Vaccines / genetics
  • Influenza Vaccines / immunology*
  • Lung / virology
  • Mice
  • Mice, Inbred BALB C
  • Orthomyxoviridae / genetics
  • Orthomyxoviridae Infections / immunology
  • Orthomyxoviridae Infections / prevention & control*
  • Rodent Diseases / immunology
  • Rodent Diseases / prevention & control
  • Survival Analysis
  • Transduction, Genetic
  • Vaccination / methods
  • Vaccines, Synthetic / administration & dosage
  • Vaccines, Synthetic / genetics
  • Vaccines, Synthetic / immunology
  • Vaccines, Virosome / administration & dosage
  • Vaccines, Virosome / genetics
  • Vaccines, Virosome / immunology

Substances

  • Antibodies, Viral
  • Influenza Vaccines
  • Vaccines, Synthetic
  • Vaccines, Virosome