Multi-antigen avian influenza a (H7N9) virus-like particles: particulate characterizations and immunogenicity
Che-Ming Jack Hu1,2, Chu-Yang Chien3, Ming-Tsan Liu4
1Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan.
Background:
Human infection with avian influenza A virus (H7N9) was first reported in China in March 2013. Since then, hundreds of cases have been confirmed showing severe symptoms with a high mortality rate. The virus was transmitted from avian species to humans and has spread to many neighboring areas, raising serious concerns over its pandemic potential. Towards containing the disease, the goal of this study is to prepare a virus-like particle (VLP) that consists of hemagglutinin (HA), neuraminidase (NA) and matrix protein 1 (M1) derived from the human isolate A/Taiwan/S02076/2013(H7N9) for potential vaccine development.
Results:
Full length HA, NA, and M1 protein genes were cloned and expressed using a baculoviral expression system, and the VLPs were generated by co-infecting insect cells with three respective recombinant baculoviruses. Nanoparticle tracking analysis and transmission electron microscopy were applied to verify the VLPs' structure and antigenicity, and the multiplicity of infection of the recombinant baculoviruses was adjusted to achieve the highest hemagglutination activity. In animal experiments, BALB/c mice and specific-pathogen-free chickens receiving the VLP immunization showed elevated hemagglutination inhibition serum titer and antibodies against NA and M1 proteins. In addition, examination of cellular immunity showed the VLP-immunized mice and chickens exhibited an increased splenic antigen-specific cytokines production.
Conclusions:
The H7N9 VLPs possess desirable immunogenicity in vivo and may serve as a candidate for vaccine development against avian influenza A (H7N9) infection.
Insights
Avian influenza A (H7N9) virus poses a pandemic threat. This study developed virus-like particles (VLPs) from H7N9 proteins, demonstrating their potential as a vaccine candidate by eliciting strong immune responses in animal models.
Area of Science:
- Virology
- Immunology
- Vaccine Development
Background:
- Avian influenza A (H7N9) virus first reported in China in 2013.
- Human infections show severe symptoms and high mortality.
- Concerns exist regarding its pandemic potential due to human-to-human transmission.
Purpose of the Study:
- To develop virus-like particles (VLPs) for H7N9 vaccine development.
- To characterize VLPs composed of hemagglutinin (HA), neuraminidase (NA), and matrix protein 1 (M1) from a human H7N9 isolate.
Main Methods:
- Cloning and expression of HA, NA, and M1 genes using a baculoviral system.
- Generation of VLPs by co-infecting insect cells.
- Verification of VLP structure and antigenicity via nanoparticle tracking and electron microscopy.
- Immunization of mice and chickens with VLPs.
Main Results:
- VLPs were successfully generated and characterized.
- VLP immunization induced elevated hemagglutination inhibition serum titers and antibodies against HA, NA, and M1 proteins in mice and chickens.
- Cellular immunity was enhanced, indicated by increased antigen-specific cytokine production in immunized animals.
Conclusions:
- The developed H7N9 VLPs exhibit desirable immunogenicity in vivo.
- These VLPs represent a promising candidate for developing a vaccine against avian influenza A (H7N9) infection.
