Fig. 2: Effects of antigen spacing and cluster number on the efficiency of ICO-RBD nanovaccine activation of B-RBD cells.
a Design of ICO-RBD nanovaccines with 1 RBD cluster of 5 RBD copies within clusters, but different RBD spacing from 10 to 40 nm. b Binding affinity between the SpyCatcher-RBD proteins (RBD) or ICO-RBD nanovaccines with different RBD spacing and B-RBD cells. ICO-RBD nanovaccines bound to B-RBD cells were detected using anti-His antibodies and flow cytometry (n = 3 independent experiments). c Ca2+ traces in B-RBD cells triggered by SpyCatcher-RBD proteins (RBD) or ICO-RBD nanovaccines with differing RBD spacing, as detected by Fluo-4 AM labeling and flow cytometry (n = 3 independent experiments). d Design of ICO-RBD nanovaccines with 1–12 RBD clusters of 5 RBD copies within clusters and 10 nm RBD spacing. e Binding affinity between the ICO-RBD nanovaccines with different RBD cluster numbers and B-RBD cells. ICO-RBD nanovaccines bound to B-RBD cells were detected using anti-His antibodies and flow cytometry (n = 3 independent experiments). f Ca2+ traces in B-RBD cells triggered by ICO-RBD nanovaccines with the different RBD cluster numbers, as detected by Fluo-4 AM labeling and flow cytometry measurement (n = 3 independent experiments). The data were processed on GraphPad Prism 8 and are presented as the mean ± SD. Statistical significance (P value) was calculated by one-way ANOVA followed by Tukey’s test. *P < 0.05; **P < 0.01; ***P < 0.001. ns, P > 0.05, no significant difference. Source data are provided as a Source Data file.
