Intranasal administration of immunogenic poly-epitope from influenza H۱N۱ and H۳N۲ viruses adjuvanted with chitin and chitosan microparticles in BALB/c mice

Objective(s): Prevalence of influenza virus, creates the need to achieve an efficient vaccine against it. We examined whether the predicted antigenic epitopes of HA, NP, and M۲ proteins of the influenza H۱N۱ and H۳N۲ viruses accompanied by chitin and chitosan biopolymers might be relevant to the induction of effective proper mucosal responses. Materials and Methods: The construct was prepared using B and T cell predicted epitopes of HA, NP, and M۲ proteins from the influenza H۱N۱ and H۳N۲ viruses by considering haplotype “d” as a dominant allele in the BALB/c mice. Intranasal immunization with purified LPS free recombinant protein together with chitin and chitosan microparticles as adjuvants was administered at an interval of ۲ weeks in thirty-five BALB/c female mice which were divided into seven groups. Ten days after the last immunization, humoral and cellular immune responses were examined. Results: Elevated systemic IgG۲a, IgA, and mucosal IgA revealed a humoral response to the construct. An increase in the number of IFN-γ-producing cells in re-stimulation of splenocytes in the culture medium by poly-tope as well as rise in the concentrations of IL-۶, IL-۱۷, and TNF-α along with the regulatory response of IL-۱۰, presented the capacity of the designed protein to provoke significant immune responses. The neutralization test ultimately confirmed the high efficacy of the protein in inhibiting the virus. Conclusion: The results support the fact that immunogenic poly-tope protein in the presence of chitin and chitosan microparticles as mucosal adjuvants is able to induce humoral and cell-mediated responses in BALB/c mice.

Keywords:

Chitin microparticles , Chitosan microparticles , Influenza H۱N۱ virus , Influenza H۳N۲ virus , Inhaled vaccine