Fig. 3: OligoD insertion into spike enhances neutralizing antibody responses.
a, Insertion of oligoD (12D) at the C-terminus of SARS-CoV-2 spike (Protein Data Bank ID: 6VXX). b, BLI binding analysis of spike or spike-12D with ACE2–Fc and three spike-specific mAbs. c, A three-dose immunization study with spike or spike-12D adjuvanted with alum via subcutaneous injection in BALB/c mice. d,e, Serum spike-specific (d) or RBD-specific (e) IgG titers over time (n = 10 mice per group). Endpoint (week 9) antibody titers are plotted on the right for comparison of the two groups. f, Serum NT50 against SARS-CoV-2 spike-pseudotyped lentiviruses over time (n = 10 mice per group). Endpoint (week 9) NT50 are plotted on the right for comparison of the two groups. g, Endpoint (week 9) NT50 against SARS-CoV-2 variants of concern from the two groups. Each circle represents a single mouse (n = 10 mice per group). Dashed lines indicate the limit of quantification in d–g. Arrows in d–f indicate prime and boost immunizations. Data are presented as geometric mean ± s.d. of the log10‐transformed values. Comparison of IgG titers (d,e) or NT50 (f) over time was performed using two-way ANOVA followed by a Bonferroni test. Comparison of two groups was performed using the two-tailed Mann–Whitney U-test (d–g). P values of 0.05 or less were considered significant.
