Effect of M2e peptide–gold nanoparticle conjugates on development of anti-influenza antibodies

Abstract

Gold nanoparticles (AuNPs) are successfully used as an adjuvant in the design of effective vaccines and in the preparation of high-affinity antibodies to haptens and complete antigens. Here, we assessed the adjuvant properties of AuNPs conjugated to a synthetic M2e peptide of the influenza A virus capsid. The resulting conjugate, a commercial influenza vaccine, and M2e in combination with different adjuvants were used to immunize laboratory mice. The highest titer was detected in the sera of mice immunized with two adjuvants: AuNPs and AuNP-conjugated CpG oligodeoxynucleotide 1826. With this combination, we also recorded increases in the respiratory activity of splenic lymphocytes, in the respiratory activity of peritoneal macrophages, and in the production of proinflammatory cytokines (IL-6 and IFN-γ). The results indicate that simultaneous immunization of the animals with two conjugates—M2e + AuNPs and CpG + AuNPs—activates antibody development. Therefore, the use of AuNPs as an antigen carrier leads to a complete and coordinated immune response from both cellular and humoral immunity.