Fig. 5: Significant enhancement of local respiratory tract immunogenicity of FPM2e formulated in LNPs. | Mucosal Immunology

Fig. 5: Significant enhancement of local respiratory tract immunogenicity of FPM2e formulated in LNPs.

From: A vaccine combination of lipid nanoparticles and a cholera toxin adjuvant derivative greatly improves lung protection against influenza virus infection

Fig. 5

a Balb/c mice were i.n immunized with 2 and 3 doses, respectively, given at 10 days apart with 5 μg FPM2e, FPM2e:LNP or FPM2e:LNPPEG and M2e-specific IgA antibodies in BAL were assessed by ELISA 10 days after the final immunization. No significant increase in specific IgA in BAL after 2 doses were recorded. The values after 3 immunizations are given as mean log10 titers ± SD of 5 mice in each group and one representative experiment of 3 giving similar results. b Detection of M2e-tetramer-specific CD4+ T cells in the lung of immunized mice. Representative FACS dot plots of M2e-tetramer+ CD4+ T cells in the different groups from one representative experiment out of 3 giving similar results (left panel). The percentage (right upper panel) and absolute number (right lower panel) of antigen primed M2e-tetramer+ CD4+ T cells are given as means ± SD of 5 mice and 3 independent experiments. c A kinetic dose-response analysis of the M2e-tetramer-specific CD4+ T cells in the lung following a single, two or three doses of FPM2e:LNP or FPM2e and means ± SD values are given in % of at least two independent experiments. d Individual lung CD4+ T cells producing IFN-γ (left panel) or IL-17A (right panel) to recall M2e-stimulation was determined by ELISPOT and values are given as mean SFC/2 × 105 cells ± SD of 5 mice and one representative experiment out of 3 giving similar results. e Detection of M2e-tetramer-specific CD4+ T cells expressing CXCR6 and CD69 in the lungs and spleen of i.n immunized mice. Representative FACS histograms of M2e-tetramer+ CD4+ T cells in the different groups from one representative experiment out of 3 giving similar results (upper panels). The percentage (lower panel) and absolute number (lower panel) of antigen primed M2e-tetramer+ CD4+ T cells expressing CXCR6 or CD69 are given as means ± SD of 5 mice and 3 independent experiments. Statistical significance was calculated by unpaired t test and p values are given as *p < 0.05 and **p < 0.01.

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