Fig. 2. Broad immune response from immunization with Quartet Nanocages.
a, Schematic of antigens for this set of immunizations, comparing uncoupled proteins or proteins coupled to the SpyCatcher003-mi3 nanocage. b, Procedure for immunization and sampling. c, ELISA for post-boost serum IgG binding to different sarbecovirus RBDs is shown as the area under the curve (AUC) of a serial dilution. Sera are from mice immunized with uncoupled SARS2 Wuhan RBD (orange), uncoupled Quartet-SpyTag (yellow), SARS2 Wuhan RBD coupled to SpyCatcher003-mi3 (green) or Quartet-SpyTag coupled to SpyCatcher003-mi3 (blue). Solid rectangles under samples indicate ELISA against a component of that vaccine (matched). Striped rectangles indicate ELISA against an antigen absent in that vaccine (mismatched). Each dot represents one animal. The mean is denoted by a bar, shown ±1 s.d.; n = 6. Significance was calculated with an ANOVA test using Tukey’s post hoc test. *P < 0.05, **P < 0.01, ***P < 0.001; other comparisons were non-significant.