Fig 2. wPPspA4Pro induces low levels of anti-PspA4 IgG.
BALB/c mice were immunized with three doses of wPPspA4Pro, wP or PspA4Pro. (A, B and F) Anti-PspA4Pro IgG (A), IgG1 and IgG2a (B) or anti-B. pertussis 18323 protein lysates (F) were measured by ELISA. (A and E), circles represent individual data and lines represent the means for each group. (B), bars represent the means for each group with the standard deviations; numbers above the bars indicate the IgG1:IgG2a ratios. Titers in control groups were below the limit of detection and, therefore IgG1:IgG2a ratios were not calculated for them. (C and D) Pools of sera from each group of mice were evaluated for the capacity to bind (C) or to induce complement deposition (D) on the surface of S. pneumoniae ATCC6303 by flow cytometry. Numbers indicate the medians of fluorescence intensity for each curve. (E) Intranasal challenge with S. pneumoniae ATCC6303 was performed in immunized mice and survival was followed for 15 days. *P<0.05; ****P<0.0001, One-way ANOVA with Tukey post-test or Log-Rank survival curve with Mantel-Cox test (E).