Figure 2.

Polyreactive and self-reactive antibodies are excluded from the IgM⁺ memory B cell compartment. (A) Antibodies from mature naive (donor JH) and IgM⁺ memory B cells (donors JH, GO, JB) were tested for self-reactivity by HEp-2 cell ELISA. HEp-2 ELISA results for antibodies from mature naive B cells of donors GO and JB have been published previously (reference 2). Dotted line shows ED38 positive control antibody (references 2, 43). Horizontal line shows cut-off OD₄₀₅ for positive reactivity as determined by comparison to low positive control serum (red line) and negative control serum (green line) from patients and healthy individuals, respectively. Pie charts summarize the frequency of HEp-2 self-reactive and nonself-reactive clones for all three donors. The number of tested antibodies is indicated in the pie chart center (reference 2). (B) Antibodies from mature naive (donor JH) and IgM⁺ memory B cells (donors JH, GO, JB) were tested for polyreactivity by ELISA with ssDNA, dsDNA, LPS, and insulin. Dotted lines represent the high positive control antibody ED38 (references 2, 43). Horizontal lines show cut-off OD₄₀₅ for positive reactivity as determined by comparison to the previously published control antibodies mGO53 (negative control; green line) and eiJB40 (low positive control; red line) (reference 2). The frequency of polyreactive antibodies in mature naive B cells from donors GO and JB has been published (reference 2). Pie charts show the frequency of polyreactive clones in mature naive and IgM⁺ memory B cell antibodies from all three donors with the number of tested antibodies indicated in the center (reference 2).