Specificity of ch2B6 and hu2B6 antibody binding to recombinant CD32B. (A) Microtiter plates were coated with soluble CD32A (▵) or CD32B (♦) Fc fusion proteins. Purified 2B6 antibodies or CD32A reactive antibodies (FLI8.26, IV.3 F(ab′)2) were added at the indicated concentrations (10 000-0.01 ng/mL). Measurements were performed in duplicate and results were normalized to a control mouse or human antibody. Error bars represent SD. (B) Stably transfected CHO cells expressing CD32A-R131 or CD32B were incubated with 5 μg/mL 2B6, ch2B6, hu2B6-3.5, FLI8.26, or IV.3 antibodies (bold line), or the appropriate isotype control antibody (dashed line) in PBS-1% BSA-SA with 10% human AB serum, followed by staining with Cy5-labeled goat F(ab′)2 fragment specific for the Fc portion of either mouse or human IgG.
