Low hemagglutinin antigen dose influenza vaccines adjuvanted with AS03 alter the long-term immune responses in BALB/c mice

Abstract

We investigated the long-term immune profiles of dose-sparing, AS03-adjuvanted vaccines compared to a traditional high-dose, unadjuvated influenza vaccine formulation. BALB/c mice received 2 IM injections of influenza A/Uruguay/716/2007 (H3N2) split vaccine antigen: high-dose (HD) (3 mg hemagglutinin (HA)/ dose) or low-dose (LD) formulations (0.03 mg or 0.003 mg HA) with AS03 and were followed to 34 weeks post-boost (pb). We examined serologic responses, spleen and bone marrow (BM) HA-specific antibodysecreting cells (ASCs) by ELISpot, influenza-specific cytokine/chemokine production in re-stimulated splenocytes by multiplex ELISA, and antigen-specific CD4C T cells that express cytokines (IL-2, IFNg, TNFa and IL-5) by flow cytometry. All formulations elicited robust serum antibody titers that persisted for at least 34 weeks. The number of antigen-specific ASCs in the spleen and BM were higher in the 2 LD CAS03 groups, but despite having fewer ASCs, the average spot size in the HD-unadjuvanted group was larger at later time-points, suggesting greater antibody production per cell. Striking differences in the long-term profiles induced by the different vaccine formulations may contribute to these different ASC profiles. The HD-unadjuvanted vaccine elicited strong Th2 cytokines during the first 6 weeks pb but LDCAS03 groups generated broader, more durable responses at later timepoints. Finally, the 0.03 mg HACAS03 group generated the greatest number of antigen-specific CD4C T cells and the highest percentage of polyfunctional cells that expressed 2 or more cytokines. Although all of the tested vaccines induced durable antibody responses, we show that different vaccine formulations (dose-sparing, adjuvant) generate distinct long-term immune profiles. Furthermore, our data suggest that the different profiles may be generated through unique mechanisms.

Development of adjuvant nanocarrier systems for seasonal influenza A (H3N2) vaccine based on Astragaloside VII and gum tragacanth (APS)

“…Cationic liposome adjuvant system CAF01, combined with trivalent influenza vaccine (TIV) enhanced influenza-specific serum antibody titers and Th1/Th17 immune response in terms of secreting IL-1b, IL-2, IL-12, IFN-c, TNF-a and IL-17 cytokines in vivo [38]. AS03 adjuvanted H1N1 vaccine administrated to Balb/c mice, and elicited Th1/Th2 mixed and Th17 immune response with high levels of IL-2, IL-17 cytokines [39]. The role of Th17 response in influenza vaccine is unclear, but its effect can be beneficial or detrimental.…”

Flublok Quadrivalent Vaccine Adjuvanted with R-DOTAP Elicits a Robust and Multifunctional CD4 T Cell Response That Is of Greater Magnitude and Functional Diversity Than Conventional Adjuvant Systems

“…The combination of antibodies of both IL-4 and IL-5 was used in both the EliSpot assay and in the ICS experiments to increase the relative signal to detect Th2 cells, which can produce both mediators [ 94 ]. No co-stimulatory antibodies were included in the stimulation assay, as is sometimes used to enhance activation of CD4+ T cells [ 95 , 96 ]. After stimulation for 2 h and blocking of cytokine secretion for the remaining 6 h (see Materials and Methods), CD4+ T cells were permeabilized and assayed for the expression of cytokines as well as cell surface proteins (see Supplementary Figure S2 for data on the panel of antibodies and gating strategies).…”