Vaccine effect of recombinant single-chain hemagglutinin protein as an antigen

Atsushi Kawai; Yasuyuki Yamamoto; Yasuo Yoshioka

doi:10.1016/j.heliyon.2020.e04301

Vaccine effect of recombinant single-chain hemagglutinin protein as an antigen

Heliyon. 2020 Jun 27;6(6):e04301. doi: 10.1016/j.heliyon.2020.e04301. eCollection 2020 Jun.

Authors

Atsushi Kawai^{1

2

3}, Yasuyuki Yamamoto^{3

4}, Yasuo Yoshioka^{1

2

3

4

5}

Affiliations

¹ Laboratory of Nano-design for Innovative Drug Development, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan.
² Vaccine Creation Group, BIKEN Innovative Vaccine Research Alliance Laboratories, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
³ Vaccine Creation Group, BIKEN Innovative Vaccine Research Alliance Laboratories, Institute for Open and Transdisciplinary Research Initiatives, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
⁴ BIKEN Center for Innovative Vaccine Research and Development, The Research Foundation for Microbial Diseases of Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
⁵ Global Center for Medical Engineering and Informatics, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan.

Abstract

Vaccination is one of the most effective interventions for preventing the spread of influenza viruses at the population level. Currently most influenza vaccines are produced by using embryonated chicken eggs, but alternative methods that achieve more rapid large-scale production are highly desirable for vaccines against both pandemic and seasonal influenza viruses. The use of recombinant hemagglutinin (HA), a key virus surface protein, as an antigen is an attractive candidate alternative approach, because of the potential for high protein yields and the ease of cloning new antigenic variants. Although fusion of HA with trimerization domains is needed to stabilize the trimeric structure and enhance the immunogenicity of the recombinant HA protein, whether the trimerization domains are immunogenic must be considered. Here, we generated recombinant multimeric HA without trimerization domains by using a short peptide linker, termed a single-chain HA (scHA), and evaluated scHAs as potential antigens for generating vaccines against influenza virus. Using mammalian cells, we succeeded in making three types of recombinant scHAs-two dimeric scHAs and a trimeric scHA. After immunization with aluminium salts in mice, one of the dimeric scHAs induced the greatest HA-specific IgG response among the scHAs and protected against virus challenge as strongly as the typically used trimeric HA containing a trimerization domain. We did not observe IgGs specific for the short peptide linker in mice immunized with the dimeric scHA, although IgGs specific for the trimerization domain occurred in mice immunized with the trimeric HA containing that domain. Furthermore, changing to another adjuvant did not diminish the utility of the dimeric scHA. These results suggest the potential usefulness of dimeric scHA as a vaccine antigen. We believe that single-chain antigens may represent new alternatives for production of recombinant antigen-based vaccines.

Keywords: Adjuvant; Hemagglutinin; Immunology; Infectious disease; Influenza virus; Microbiology; Pharmaceutical science; Pharmacology; Proteins; Recombinant protein; Vaccine; Virology.