Frontiers in Veterinary Science (Feb 2020)

Immunogenicity Assessment of Rift Valley Fever Virus Virus-Like Particles in BALB/c Mice

  • Yuetao Li,
  • Yuetao Li,
  • Yuetao Li,
  • Li Han,
  • Yongkun Zhao,
  • Xuexing Zheng,
  • Xuexing Zheng,
  • Hualei Wang,
  • Hualei Wang,
  • Weiwei Gai,
  • Hongli Jin,
  • Guohua Li,
  • Qi Wang,
  • Na Feng,
  • Yuwei Gao,
  • Songtao Yang,
  • Xianzhu Xia

DOI
https://doi.org/10.3389/fvets.2020.00062
Journal volume & issue
Vol. 7

Abstract

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Rift Valley fever (RVF) is an acute, febrile zoonotic disease that is caused by the RVF virus (RVFV) and is spread by arthropod vectors. Virus-like particle (VLP) vaccines, which have the advantages of strong immunogenicity and safety, play an important role in the prevention of this disease. VLPs for RVFV were successfully prepared by our research group using a baculovirus-insect cell expression system. To study the immunogenicity of these RVFV VLPs, a correct 3rd or 4th generation recombinant baculovirus, rBac-N-G, was identified and used to infect Sf9 cells, which were cultured in suspension at a large scale. Subsequently, cell debris was removed by centrifugation, and the VLPs were concentrated by ultracentrifugation and purified using a sucrose gradient, after which they were used to immunize BALB/c mice by intramuscular injection. The results showed that the RVFV VLPs prepared by our research group could effectively induce mice to produce RVFV neutralizing antibodies and that the prepared VLPs could stimulate mouse spleen cells to produce high levels of the cytokines IL-4 and IFN-γ. Moreover, the proportion of lymphocytes producing IL-4 and IFN-γ in the spleen of mice immunized with RVFV VLPs was significantly increased. Therefore, the RVFV VLPs prepared in this study had strong immunogenicity and could effectively activate humoral and cellular immunity in mice. This study lays a solid foundation for the development of RVFV VLP vaccine candidates and promotes the healthy development of animal husbandry and human public health.

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