Figure 4.

Analysis of MBC-derived antibody response in supernatants of CD40L/IL-21 stimulated B cells from Sputnik V-vaccinated individuals. (A) Production of RBD-specific IgG (left panel), IgA (middle panel) or IgM (right panel) in cultures of IL-21/CD40L-stimulated B cells from Sputnik V-vaccinated individuals evaluated using ELISA. (B) Virus-neutralizing activity of MBC-derived antibodies against WA1 strain (left panel) and Beta variant (right panel) at T2 and T3 time points. (C) Paired analysis of virus-neutralizing activity of MBC-derived antibodies against WA1 strain and Beta variant at T3 time point. (D) Spearman’s correlation between virus neutralization (%) and the levels of anti-RBD IgG in supernatants of IL-21/CD40L-stimulated B cells obtained from Sputnik V-vaccinated individuals at T3 time point. (E) Spearman’s correlation between the virus-neutralizing activity of plasma and MBC-derived antibodies. Each symbol represents half-maximal inhibitory plasma dilution (ID₅₀) values and % of virus neutralization by supernatant of IL-21/CD40L-stimulated B cells. (F) Heatmap and hierarchical clustering of Sputnik V recipients. Columns denote Sputnik V recipients. Rows correspond to immune response variables. Dendrograms on the top illustrate the clustering of Sputnik V recipients. Immune response measurement values are color-coded according to the key shown in the upper left. (G) Principal component analysis of Sputnik V recipients. Recipient IDs are shown. Two distinct clusters are indicated by the ovals. Results are shown for individual samples (symbols) from naïve (n = 17) and recovered (n = 5) recipients. Data are presented as median ± IQR. Asterisks indicate significant difference between groups determined using the Kruskal–Wallis test, statistics in (C) panel were calculated using Mann-Whitney test. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001, ns, not significant. IQR, interquartile range; RBD, receptor-binding domain.