Comparison of Chicken Immune Responses after Inoculation with H5 Avian Influenza Virus-like Particles Produced by Insect Cells or Pupae

Dean Huang; Yu-Chan Chao; Zhengbing Lv; Jia-Tsrong Jan; Yu-Chih Yang; Pei-Wen Hsiao; Chia-Ying Wu; Chiu-Hsun Liao; Tzu-Hsien Wu; Lih-Chiann Wang

doi:10.2478/jvetres-2021-0026

Comparison of Chicken Immune Responses after Inoculation with H5 Avian Influenza Virus-like Particles Produced by Insect Cells or Pupae

J Vet Res. 2021 May 22;65(2):139-145. doi: 10.2478/jvetres-2021-0026. eCollection 2021 Jun.

Authors

Affiliations

¹ School of Veterinary Medicine, National Taiwan University, Taipei 10617, Taiwan.
² Academia Sinica, Taipei 11529, Taiwan.
³ College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China.
⁴ Miaoli District Agricultural Research and Extension Station, Council of Agriculture, Miaoli 36346, Taiwan.

Abstract

Introduction: Novel clade 2.3.4.4 H5 highly pathogenic avian influenza virus (HPAIV) outbreaks have occurred since early 2015 in Taiwan and impacted the island economically, like they have many countries. This research investigates the immunogenicity of two HPAIV-like particles to assess their promise as vaccine candidates.

Material and methods: The haemagglutinin (HA) gene derived from clade 2.3.4.4 H5 HPAIV and matrix protein 1 (M1) gene were cloned into the pFastBac Dual baculovirus vector. The resulting recombinant viruses were expressed in Spodoptera frugiperda moth (Sf)21 cells and silkworm pupae to generate Sf21 virus-like particles (VLP) and silkworm pupa VLP. Two-week-old specific pathogen-free chickens were immunised and their humoral and cellular immune responses were analysed.

Results: The silkworm pupa VLP had higher haemagglutination competence. Both VLP types elicited haemagglutination inhibition antibodies, anti-HA antibodies, splenic interferon gamma (IFN-γ) and interleukin 4 (IL-4) mRNA expression, and CD4⁺/CD8⁺ ratio elevation. However, chickens receiving silkworm pupa VLP exhibited a significantly higher anti-HA antibody titre in ELISA after vaccination. Although Sf21 VLP recipients expressed more IFN-γ and IL-4, the increase in IFN-γ did not significantly raise the CD4⁺/CD8⁺ ratio and the increase in IL-4 did not promote anti-HA antibodies.

Conclusion: Both VLP systems possess desirable immunogenicity in vivo. However, in respect of immunogenic efficacy and the production cost, pupa VLP may be the superior vaccine candidate against clade 2.3.4.4 H5 HPAIV infection.

Keywords: avian influenza virus; clade 2.3.4.4; silkworm pupa; vaccine; virus-like particle.