Influenza viral vectors expressing two kinds of HA proteins for bivalent vaccines against clade 2.3.4.4 and clade 2.3.2.1 H5 HPAIVs

Sci Rep. 2018 Jun 19;8(1):9327. doi: 10.1038/s41598-018-27722-5.

Abstract

The H5 highly pathogenic avian influenza viruses (HPAIVs) in China pose a serious challenge to public health and the poultry industry. In this study, we constructed a replication-competent recombinant influenza A virus of clade 2.3.4.4 Н5N1 expressing the clade 2.3.2.1 H5 HA1 protein from a tricistronic NS segment. We used a truncated NS1 protein of 73 amino acids combined with a heterologous dimerization domain to increase protein stability. H5 HA1 and nuclear export information were fused in frame with a truncated NS1 open reading frame, separated by 2A self-processing sites. The resulting PR8-H5-NS1(73)H5 stably expressed clade 2.3.4.4 H5 HA and clade 2.3.2.1 H5 HA1 proteins and exhibited similar in vitro growth kinetics as the parental PR8-2344H5 virus. PR8-H5-NS1(73)H5 induced specific hemagglutination-inhibition (HI) antibody against clade 2.3.4.4 H5 that was comparable to that of the combination vaccine of PR8-2344H5 and PR8-2321H5. HI antibody titers were significantly lower against clade 2.3.2.1 H5 virus than with the combination vaccine. PR8-H5-NS1(73)H5 completely protected chickens from both clade 2.3.4.4 and clade 2.3.2.1 H5 HPAIVs challenge. Our results suggested that PR8-H5-NS1(73)H5 was highly immunogenic and efficacious against both clade 2.3.4.4 and clade 2.3.2.1 H5 HPAIVs in chickens.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • Chickens
  • Genetic Vectors / genetics*
  • Hemagglutinin Glycoproteins, Influenza Virus / genetics
  • Hemagglutinin Glycoproteins, Influenza Virus / metabolism*
  • Influenza Vaccines / immunology*
  • Open Reading Frames / genetics
  • Protein Stability
  • Vaccines, Inactivated / immunology
  • Vaccines, Inactivated / therapeutic use
  • Viral Nonstructural Proteins / genetics
  • Viral Nonstructural Proteins / metabolism*

Substances

  • Hemagglutinin Glycoproteins, Influenza Virus
  • Influenza Vaccines
  • Vaccines, Inactivated
  • Viral Nonstructural Proteins