Intranasal Immunization with Recombinant HA and Mast Cell Activator C48/80 Elicits Protective Immunity against 2009 Pandemic H1N1 Influenza in Mice

Abstract

BackgroundPandemic influenza represents a major threat to global health. Vaccination is the most economic and effective strategy to control influenza pandemic. Conventional vaccine approach, despite being effective, has a number of major deficiencies including limited range of protection, total dependence on embryonated eggs for production, and time consuming for vaccine production. There is an urgent need to develop novel vaccine strategies to overcome these deficiencies.Methodology/Principal FindingsThe major objective of this work was to develop a novel vaccine strategy combining recombinant haemagglutinin (HA) protein and a master cell (MC) activator C48/80 for intranasal immunization. We demonstrated in BALB/c mice that MC activator C48/80 had strong adjuvant activity when co-administered with recombinant HA protein intranasally. Vaccination with C48/80 significantly increased the serum IgG and mucosal surface IgA antibody responses against HA protein. Such increases correlated with stronger and durable neutralizing antibody activities, offering protection to vaccinated animals from disease progression after challenge with lethal dose of A/California/04/2009 live virus. Furthermore, protected animals demonstrated significant reduction in lung virus titers, minimal structural alteration in lung tissues as well as higher and balanced production of Th1 and Th2 cytokines in the stimulated splenocytes when compared to those without C48/80.Conclusions/SignificanceThe present study demonstrates that the novel vaccine approach of combining recombinant HA and mucosal adjuvant C48/80 is safe and effective in eliciting protective immunity in mice. Future studies on the mechanism of action of C48/80 and potential combination with other vaccine strategies such as prime and boost approach may help to induce even more potent and broad immune responses against viruses from various clades.

Cross-protection against influenza virus infection by intranasal administration of nucleoprotein-based vaccine with compound 48/80 adjuvant

“…26 Meng et al also showed that the immunization of mice with C48/80 plus influenza HA expressed in eukaryotic cells could induce the balanced Th1/Th2 responses, preferentially inducing Th2-biased immune responses. 11 These were consistent with our experimental results. However, different from NP, HA as surface glycoprotein is prone to variation, and is not suitable to be used as the antigen of UIV.…”

“…[23][24][25] Some studies showed that mast cells might promote the adaptive immunity through the effector function or by releasing various cytokines, chemokines and growth factors. 11 Therefore, recently, people have started to study the efficacy of MC activator C48/80 as an adjuvant, and C48/80 has been shown to be a potential mucosal adjuvant. Just like other mucosal adjuvants, C48/80 as a nontoxic nasal adjuvant 12 can also induce effective sIgA at the mucosal location, and clear the virus in the early stage of pathogen invasion, playing an immunological effect.…”

Use of recombinant flagellin in oil-in-water emulsions enhances hemagglutinin-specific mucosal IgA production and IL-17 secreting T cells against H5N1 avian influenza virus infection

“…A similar dosage of HA for three-dose i.n. immunization was reported by others, including chitosan nanoparticles (15 g HA per dose) [30,31] or co-delivery with a mast cell activator protein (9 g HA per dose) [32]. We found that the recombinant H5HA protein antigen had to be formulated in oil-in-water emulsions (i.e.…”

Mucosal vaccine delivery: Current state and a pediatric perspective

“…Among them are γ-PGA, α-galactosylceramide - a CD1d ligand, and Iscomatrix (colloidal, spherical structures, comprising of saponin such as Quil A, cholesterol and a phospholipid), which have been used in different vaccine studies [131, 245–247]. Furthermore, a mast cell activating compound C48/80 has been shown to be a safe and effective nasal adjuvant in mice [248, 249]. Water soluble vitamin E derivative (d-α-tocopheryl polyethylene glycol 1000 succinate) is also suggested as a promising nasal vaccination potentiator [250].…”