Figure 1. Peripheral tolerance removes self-reactive mature B cells in healthy donors.

Reactivity of clonal Abs in culture supernatants of individual single B cell cultures (n = 429 from transitional B cell cultures and n = 654 from mature B cell cultures) from healthy individuals were tested against 4 positive and negative controls (anti-IgG, anti-Igκ, anti-Igλ, and BSA) and a panel of self- and foreign antigens by Luminex multiplex assays. (A and B) Representative diagrams for transitional B cells (A) and mature B cells (B) from healthy donors. Each dot represents an individual test for each antigen. Figures represent n = 82 and n = 92 for transitional B and mature B cells, respectively. Blue bars indicate the threshold median fluorescence intensities (MFI) for each antigen (average + 6SD of B cell–negative, mock-treated samples). Number of positive reactions is indicated for each antigen above each panel. We tested subsets (n = 145 and n = 213 for transitional and mature B cells, respectively) of culture supernatant IgGs for binding to HAs. (C and D) Frequency of self-reactive B cells in transitional and mature B cells (n = 9). (C) Boxes extend from the 25th to 75th percentile, and lines in the boxes represent medians. Error bars represent minimum to maximum values. (D) Each dot represents an individual subject. For each individual, frequencies of self-reactive B cells were normalized with those of transitional B cells, and transitional and mature B cells are connected with lines.**P < 0.01 determined by Wilcoxon’s matched-pairs signed-rank test.