Study on the immunogenicity of virus-like particles of dengue virus type 2 ZS01/01 strain

Abstract

Objective To study the immunogenicity of virus-like particles (VLPs) of dengue virus type 2 (DENV-2) ZS01/01 strain.Methods Secreted VLPs of DENV-2 ZS01/01 strain were purified by ultracentrifugation from 293T cells transfected with plasmid which was established previously in our lab.After identified by Western Blot analysis and transmission electron microscope (TEM),the immunogenicity of DENV-2 VLPs was evaluated in BALB/c mice.Humoral immune responses were identified by ELISA and CPE-based neutralization analysis while cellular immune responses were detected by ELISPOT.Results The analysis of humoral immune responses revealed that DENV-2 VLPs induced high levels of dengue rEIII-specific IgG antibodies and elicited homotypic neutralizing antibodies against DENV-2 NGC strain.Furthermore,spleen cells from mice vaccinated with DENV-2 VLPs and virions produced comparable levels of IFN-γ.Conclusion Monovalent DENV-2 VLPs produced by mammalian cells were capable to induce dengue-specific humoral and cellular immune responses in mice,and this may open a promising approach to the development of tetravalent dengue VLPs vaccine. Key words: Dengue virus; Virus-like particles; Immunogenetics