Vaccine containing G protein fragment and recombinant baculovirus expressing M2 protein induces protective immunity to respiratory syncytial virus.
- Author:
Yeong Min JO
1
;
Jungwoo KIM
;
Jun CHANG
Author Information
- Publication Type:Original Article
- Keywords: Respiratory syncytial virus; Vaccine; Recombinant baculovirus; M2; G protein
- MeSH: Aged; Animals; Asthma; Baculoviridae*; Bronchiolitis; Enzyme-Linked Immunosorbent Assay; Eosinophils; Flow Cytometry; GTP-Binding Proteins*; Humans; Immunity, Cellular; Immunity, Humoral; Immunoglobulin G; Infant; Mice; Pneumonia; Respiratory Syncytial Viruses*; T-Lymphocytes
- From:Clinical and Experimental Vaccine Research 2019;8(1):43-53
- CountryRepublic of Korea
- Language:English
- Abstract: PURPOSE: Respiratory syncytial virus (RSV) can cause serious respiratory illnesses such as pneumonia, asthma, and bronchiolitis in infants and elderly or immunocompromised individuals. An RSV vaccine has yet to be developed; only prophylactic anti-RSV antibody is commercially available. So, we investigated whether our vaccine candidate is able to induce type 1 CD4+ T helper (Th1), CD8+ T-cell responses, and protective immunity without vaccine-enhanced disease (VED) against RSV. MATERIALS AND METHODS: We used RSV G protein fragment (Gcf A) with recombinant baculovirus capable of expressing the RSV M2 protein (Bac M2) as a vaccine candidate, and injected this vaccine (Gcf A/Bac M2) intramuscularly, and challenged with RSV intranasally into mice. Enzyme-linked immunosorbent assay, flow cytometry, plaque assay, and weight measurement were performed to confirm humoral immunity, cellular immunity, and protective immunity. RESULTS: The Gcf A/Bac M2 formulation induced a stronger IgG response to Gcf A than Gcf A inoculation alone, and the ratio of IgG1/IgG2a indicated that the responses shifted predominantly to Th1. In addition, both RSV G-specific Th1 responses and RSV M2-specific CD8+ T-cell responses were induced, and G protein-associated eosinophilic infiltration was suppressed compared to the control group. Moreover, the Gcf A/Bac M2 group showed effective protection after an RSV challenge. CONCLUSION: Bac M2 could serve as a vaccine with intrinsic adjuvant activity, and the Gcf A/Bac M2 shows promise as a vaccine candidate for inducing protective immunity without inciting VED.
