PBMC from two patients with high circulating naive B-cell counts, TOL patient 002002 and SI patient 002055 were assayed directly (PBMC, filled squares), after being depleted of CD19+ B cells (open triangles) or after depletion and add-back of B-cell fraction (gray circles). Cell fractions were injected into the footpad with PBS (negative control, data not shown) with recall antigen (TT/DT or EBV, left panel), recall antigen and self-peptide (p37TE or HA-1R, middle panel) or recall antigen and donor peptide (p37MA, or HA-1H, right panel). Swelling was measured before and 24 h after each injection. Net swelling was determined by subtracting the swelling response obtained from the injection of the same cell fractions in PBS.