Journal: Vaccine

Article Title: Immunization with a recombinant BibA surface protein confers immunity and protects mice against group B Streptococcus (GBS) vaginal colonization.

doi: 10.1016/j.vaccine.2020.05.076

Figure Lengend Snippet: Fig. 1. Antibodies raised in mice immunized with rBibA bind to the native protein exposed on the surface of GBS cells of different serotypes. (A) Whole-cell ELISA performed with GBS cells belonging to different serotypes and serum samples collected 2 weeks after the third immunization with rBibA admixed with alum. Values represent the mean ± SD. Significant differences between groups were determined using two-way ANOVA with Tukey’s post hoc test. ****p < 0.0001, ***p < 0.001, and *p < 0.05; ns: nonsignificant. (B) Immunofluorescence detection of GBS-V using antibodies raised in BALB/c mice immunized with rBibA. Tested antibodies: i) anti-S. agalactiae monoclonal antibody (mAb 224/46) (Novus Biologicals), ii) polyclonal serum raised against whole inactivated GBS-V (anti-GBS-V), iii) serum samples from mice immunized with rBibA- alum (anti-BibA), and iv) serum samples collected from saline-treated mice (non-immune serum). Cells were evaluated on an AMG EVOS flLED fluorescence microscope at a magnification of 40. Scale bar: 100 mm. The columns show transmitted light (left), GFP fluorescence (center) and merged images (right). Red arrows point GBS-V cells detected by the indicated antibody. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)

Article Snippet: The wells were incubated with the following primary antibodies: i) anti-S. agalactiae monoclonal antibody (224/46) (1:100) (Novus Biologicals), ii) polyclonal serum raised against GBS-V (1:50), iii) polyclonal serum raised against BibA-alum (1:50), and iv) control serum raised against saline (1:50).

Techniques: Enzyme-linked Immunosorbent Assay, Saline, Microscopy