Screening panel for in vitro restimulation of FVIII-specific memory B cells in the presence of FVIII and CpG. CD138⁻ spleen cells were obtained from hemophilic mice treated with 4 weekly doses of 200 ng of FVIII and restimulated with stimulating (10 ng/mL) and inhibiting (1 and 20 μg/mL) concentrations of FVIII in the presence of CpG-ODN. Newly formed anti-FVIII ASC were detected by ELISPOT assay after 6 days of culture. Each spot represents one anti-FVIII ASC. Concentrations of FVIII and CpG-ODN are indicated. A representative ELISPOT is presented.