Evaluation of Antibody and Cytokines Responses in Intranasally and Intramuscularly Administrated BALB/C Mice With Influenza Virus-Like Particle

We previously developed an influenza virus like particle with HA, M, and NA proteins using Bac-to-Bac expression system and SF9 cell line. To evaluate the immunogenicity of our construct, we assessed the humoral, cytokine induced by H1N1-VLP in BALB/c mice immunized intranasally and intramuscularly. Enzyme-linked immunosorbent assay and Relative quantitative real-time PCR were used to evaluate the antibody (IgG and IgA) and mRNA levels of IL-6, IL-4, IL-10 and IFN-g in PBMCs. Our results showed that VLP was capable of intranasal (I.N.) and intramuscular (I.M.) induction of serum IgG and IgA responses. Interestingly, I.N. route induced higher IgG and IgA titer than I.M. route, which was statistically significant. Moreover, mRNA levels of IL-6 (4.2-4.5 folds), IFN-g (5.5-5.7 folds), and the anti-inflammatory cytokine IL-10 (2.5-3 folds) and IL-4 (2.4-2.8 folds) were significantly elevated in mice immunized I.N. and I.M. with H1N1-VLP compared to the control group. Our findings indicated that a non-infectious genome-less VLP approach mimics parenteral virus with multiple viral antigens and epitopes that stimulate a diverse set of immune responses such as innate immunity, specific serum IgG antibody, cell-mediated immunity, and local antibodies.