Fig. 6

CMR-PLGA/p54 NVs enhanced immune responses in vivo. A The proliferation percentage analysis of splenocytes. Splenocytes harvested from immunized mice were re-stimulated with different groups overnight. B The IFN-γ content in medium after re-stimulation. Flow cytometry analysis (C, E) and statistic analysis (D, F) of activated splenic CD8⁺ and CD4⁺ T cells. The splenic T cells were collected from mice following the immunization as described in Fig. 5A. G The level of IgG in serum collected from mice immunized with different groups. H The ratio of IgG2a to IgG1 in serum from immunized mice. I Changes in specific IgG titers in mice after immunization with different vaccine components. J The p54-specific IgG antibody titers in serum measured by ELISA on day 49 (n = 8). K Immunohistochemical staining of CD21 in spleen harvested from immunized mice. Bar represents 100 μm. Flow cytometry analysis (L) and statistic analysis (M) of maturated CD19⁺ IgD⁺ B cells