Fig. 2: Characterisation of the BP vaccines.
a Analysis of BP-associated proteins using SDS-PAGE indicated by blue arrows. Lane 1, Molecular weight standard (Mark12™ Unstained protein standard); Lane 2, Empty BPs; Lane 3, B-cell epitope BPs; Lane 4, B/T-cell epitope BPs. Blue arrows indicate respective full-length fusion protein corresponding with their expected molecular weight. b TEM images of the BPs. Individual BPs are indicated by red arrows. c Bubble graph showing properties of BPs. Polydispersity index (PDI) is shown along the x-axis, Zeta potential is shown along the y-axis, while size of bubbles indicates average BP size. All data were collected from three technical replicates. d Graph showing protein proportion of total BP mass determined by densitometry using Image J and known BSA standards. e Graph showing % w/w of PHB contributing to whole-cell mass or purified BP mass as determined by HPLC. f Immunoblot analysis to assess specific recognition of B- and B/T-cell epitopes presented by BPs using the monoclonal anti-NANP3 antibody. g Average EC50 titre of the monoclonal antibody binding to B- and B/T-cell epitope-coated BPs. Statistical significance was determined by Nonparametric Mann–Whitney (Minitab 19) when p < 0.05. BPs used for the animal trial were analysed using three replicates. All EC50 values were statistically significant from one another. p = 0.007 for empty BPs compared with B-cell epitope BPs. p = 0.002 for Empty BPs compared with B/T-cell epitope BPs. p = 0.03 for B-cell epitope BPs compared with B/T-cell epitope BPs. All data are mean and error bars represent +/–SD.
