Fig. 2.

Vaccination with recombinant glycoproteins generates antibodies that recognise homologous and heterologous pneumococcal isolates. a-c Anti-carrier protein antibodies were measured from mice vaccinated with Combo(Sp4) (closed circles) or Combo (open squares) by sandwich ELISA using a monoclonal anti-His capture antibody and recombinant, unglycosylated carrier proteins. Data are displayed as mean ± SEM from technical replicates. d, e Anti-ST4 d and anti-ST2 e antibodies were measured by whole-cell ELISA using pooled antiserum from the glycosylated (black bars) and unglycosylated (white bars) vaccine groups. Data are displayed as mean ± SEM from three separate cultures. *p < 0.05 vs PBS, ^#p < 0.05 protein vs glycoprotein, ^†p < 0.05 vs Prevnar-13 one-way ANOVA with Bonferroni’s post-test. f Immunoblot analysis of concentrated lysate from ST4 and ST2 overnight cultures using pooled antiserum from the glycosylated and unglycosylated vaccine groups. Molecular mass markers are given in kilodaltons