Fluorescence-activated cell sorter (FACS) analysis of expression of CD40, HLA-DR, CD80, and CD86 molecules by immature DCs from a healthy subject and from HIGM3 patients 1 and 2. Monocyte-derived immature DCs were cultured as described in “Patients, materials, and methods,” incubated with the appropriate antibody, washed twice, and analyzed using a flow cytometer. Expression of CD80 and CD86 was analyzed by CD80-FITC/CD86-PE double staining. Expression of CD40 was analyzed by CD40-FITC single staining (except for HIGM3 patient 1, in whom we used PE-conjugated anti-CD40 mAb) and HLA-DR expression by HLA-DR-PE staining. CD40, HLA-DR, CD80, and CD86 antibody stainings are presented (thick line) in comparison with mouse IgG antibody (thin line). The x-axis represents the intensity of green (or red) fluorescence expressed in a log scale as mean channel, and the y-axis represents the number of cells per channel. Data shown are from 1 of 3 representative, independent experiments.