Poster Presentation International Veterinary Immunology Symposium 2016

A new generation (third) of quillaja nanoparticles is a promising affordable adjuvant for animal use (#115)

Caroline Fossum 1 , Bernt Hjertner 1 , Stina Hellman 1 , Theresa Bengtsson 2 , Staffan Pauli 2 , Bror Morein 1
  1. Swedish University of Agricultural Sciences, Uppsala, Sweden
  2. Mabtech AB, Nacka, Sweden

A new generation of adjuvant (“G3”), composed of Quillaja saponin and cholesterol, was tested for cytokine induction in porcine cells and as adjuvant for a commercial influenza virus vaccine in mice. The spherical, 20nm G3 nanoparticle has a high bioavailability, the production is robust to a comparatively low cost. Thus, the G3 is a suitable adjuvant candidate for veterinary vaccines. The G3 adjuvant alone induced in a dose-dependent manner transcription of the genes for IFN-γ and IL-17A in cultures of porcine lymphocytes and for IFN-α in porcine macrophages as well as for TNF-α, IL-1β, IL-6 and IL-8 in both types of cultures. The adjuvant effect of G3 was compared to that of alum in mice immunized twice, six weeks apart, with an inactivated split human influenza virus (Flu ag). Splenocytes were collected one week after booster immunization and tested for cytokine production after in vitro restimulation. The cytokine secretion was determined by ELISpot (TNF-α, IL-4) or FluoroSpot (IFNγ/IL-2, IFNγ/IL-5, IFNγ/IL-17 double secreting cells). The number of ag-specific IgG secreting B cells was analyzed with the FluoroSpot technique (Mabtech AB). In summary, mice immunized with G3 displayed the highest numbers of antigen-specific B cells, the highest number of antigen-specific IFNγ-secreting T cells and the lowest numbers of IL-4 and IL-5 secreting cells. Mice immunized with Flu ag adjuvanted with G3 had a considerably higher number of IL-2/IFNγ double secreting cells than those immunized with Flu ag alone or in combination with alum. This cell phenotype is associated with a long-term effect of vaccines encouraging further evaluation of G3 as an adjuvant.