Reverse micelle-encapsulated recombinant baculovirus as an oral vaccine against H5N1 infection in mice

Antiviral Res. 2010 May;86(2):180-7. doi: 10.1016/j.antiviral.2010.02.315. Epub 2010 Feb 12.

Abstract

Induction of mucosal immunity through oral immunization is an effective way to control influenza infection. In this study, baculovirus displaying influenza hemagglutinin was encapsulated within a reverse micelle structure of phosphatidylcholine and delivered into the gastrointestinal tract of mice to study its efficacy as an oral vaccine against cross-clade H5N1 infection. Mice vaccinated with encapsulated baculovirus displaying HA (En-BacHA) showed significantly enhanced HA specific serum IgG and mucosal IgA antibodies, and higher hemagglutination inhibition (HI) titers, when compared to its non-encapsulated form (BacHA). Estimation of serum neutralizing antibodies also indicated that En-BacHA formulation was able to induce strong cross-clade neutralization against heterologous H5N1 strains (clade 1.0, clade 2.1, clade 4.0 and clade 8.0). Further, mice vaccinated with En-BacHA alone were able to confer 100% protection against 5MLD50 of HPAI heterologous H5N1 strain (clade 1). Inclusion of recombinant cholera toxin B subunit as a mucosal adjuvant in the vaccine formulation did not show any significant effect in both systemic and mucosal immune responses. Oral delivery of encapsulated recombinant H5 HA expressed on baculovirus surface is an effective way to prime the immune system against H5N1 infection in mice and will have no biosafety concerns associated with their production or administration.

MeSH terms

  • Adjuvants, Immunologic / administration & dosage
  • Administration, Oral
  • Animals
  • Antibodies, Neutralizing / blood
  • Antibodies, Viral / analysis
  • Antibodies, Viral / blood
  • Baculoviridae / genetics*
  • Cholera Toxin / administration & dosage
  • Cross Reactions
  • Female
  • Genetic Vectors*
  • Hemagglutination Inhibition Tests
  • Hemagglutinin Glycoproteins, Influenza Virus / genetics
  • Hemagglutinin Glycoproteins, Influenza Virus / immunology*
  • Immunoglobulin A / analysis
  • Immunoglobulin G / blood
  • Influenza A Virus, H5N1 Subtype / genetics
  • Influenza A Virus, H5N1 Subtype / immunology*
  • Influenza Vaccines / administration & dosage
  • Influenza Vaccines / genetics
  • Influenza Vaccines / immunology*
  • Mice
  • Mice, Inbred BALB C
  • Mucous Membrane / immunology
  • Orthomyxoviridae Infections / prevention & control
  • Survival Analysis

Substances

  • Adjuvants, Immunologic
  • Antibodies, Neutralizing
  • Antibodies, Viral
  • Hemagglutinin Glycoproteins, Influenza Virus
  • Immunoglobulin A
  • Immunoglobulin G
  • Influenza Vaccines
  • hemagglutinin, avian influenza A virus
  • Cholera Toxin