Figure 3.

Identification of ACPA-producing plasmablast clonal families containing divergent antibodies that exhibit differential polyreactive binding to citrullinated epitopes. (A) rMabs deriving from the three ACPA clonal families were expressed and tested by ELISA for reactivity against citrullinated peptides and their native counterparts. Cut-off values for each peptide were set at three standard deviations above the average of the negative controls. The dotted line represents the normalized cut-off for positive hits (fold change >1). Data are presented as mean +/− SEM and representative of at least three replicated experiments. (B-D) Heatmaps summarizing ELISA data for mAbs deriving from clonal families 1 (B), 2 (C), and 3 (D) binding to various citrullinated peptides. Data are representative of three replicated experiments. Mean reactivity of positive hits (fold change - 1 > 0) are displayed in colored gradient from yellow to red. White indicates no detectable reactivity (fold change - 1 ≤ 0). Gray indicates data not available. CF, clonal family; cyc, cyclic; vim, vimentin