Fig. 5: The properties, antigenicity, and immunogenicity characterization of triple-type chimeric single-particle vaccine candidate molecules.

Transmission electron microscopy (TEM) images, scale bar, 100 nm (a), high-performance size-exclusion chromatography (HPSEC) profiles (b), analytical ultracentrifugation sedimentation (AUC) profiles (c), differential scanning calorimetry (DSC) profiles (d) and cryo-EM structures (radially colored from 240 Å to 300 Å) of H39–68FG-70DE and H39–68FG-70HI chimeric VLPs (e). f Heatmap representations of the EC₅₀ values of HPV39/68/70 chimeric VLPs based on ELISA assays against a type-specific mAb panel of HPV39, −68 and −70 VLPs. The key indicates the heatmap gradient. A detailed characterization of each mAb is shown in Supplementary Table 4. g Immunogenicity of HPV39/68/70 cross-type vaccine candidate in BALB/c mice. BALB/c mice (n = 8) were inoculated intraperitoneally with one of four doses (0.300, 0.100, 0.033 or 0.011 μg/dose) of HPV39/68/70 cross-type vaccine candidate at weeks 0, 4, and 8. The neutralization antibody levels at week 10 after the first immunization were tested by neutralization assays. The dotted line indicates the limit of detection for the assay. All data were analyzed by one-way analysis of variance (ANOVA) and are presented as mean ± standard deviation (SD); *P < 0.05, **P < 0.01; ***P < 0.001; ****P < 0.0001. The error bars reflect the SD and the symbols represent the individual mice.