Fig. 2: pCTV-WS immunogenicity and protection in immunized K18-hACE2 mice.
a Schematic representation of the experimental design used to assess humoral and cellular immune response and protection against SARS-CoV-2. b Anti-WS total IgG titer in pCTVØ (open circles) or pCTV-WS (gray circles) immunized mice after 1st immunization (prime) and pCTVØ (filled circles) or pCTV-WS (red circles) after prime/boost [n = 8 mice/group]. c IgG1 (blue circles) and IgG2c (red circles) subclass 30 days after prime/boost pCTV-WS immunization. IgG1 (open circle) and IgG2c (filled circle) in the control group [n = 8 mice/group]. d Anti-WS total IgG in bronchoalveolar lavage (BAL) from mice immunized with pCTVØ (black circles) or pCTV-WS (red circles) [n = 8 mice/group]. e IFN-γ levels produced by splenocytes from pCTVØ (black circles) or pCTV-WS (red circles) immunized mice after 72 h of incubation with medium (negative control), restimulation with recombinant WS protein or Concanavalin A (positive control) [n = 8, pCTVØ and n = 20, pCTV-WS]. IFN-γ production by CD4+ T cells and CD8+ T cells from immunized mice stimulated in vitro with WS protein f or from mice challenged with Wuhan strain at 5DPI g (n = 4 for both groups). Data pooled from two independent experiments. The statistical analysis of IgG measured in BAL and IFN-γ measurements was performed using unpaired t-test or Mann-Whitney U test, according to data distribution. Bars represent mean ± SEM. *p < 0.05; **p < 0.01; ***p < 0.001.
