Analysis of circulating plasmacytoid DCs and IFN-α-secreting cells in HIGM3 patients. (A) Percentages of circulating myeloid and plasmacytoid DCs and IFN-α secretion after HSV-1 infection. Percentages of circulating DCs were calculated over total mononuclear leukocytes after exclusion of Lin⁺ cells stained, as described in “Patients, materials, and methods.” MDC indicates myeloid CD11c⁺ DCs; PDC, plasmacytoid CD123⁺ DCs; ▪, healthy control; ▦, patient 1; and □, patient 2. (B) Capacity of IFN-α secretion by total PBMCs (2 × 10⁵ cells/well) after HSV-1 infection with a decreasing dilution titer of the virus isolate (1:10 000, 1:1000, 1:500) was assessed in patients with CD40 deficiency and in healthy controls. Culture supernatants were harvested after 24 hours, and IFN-α levels were determined using ELISA. Data are expressed in pg/10 × 10⁵ PBMCs (mean ± SD of experiment performed in triplicate). Data from the healthy subject (♦) are representative of data from all the control group subjects. ^*Significant difference in the control subject in comparison with patients as assessed by statistical analysis (P < .05). ♦ indicates healthy subject; □, HIGM3 patient 1; and ▴, HIGM3 patient 2. Results are representative of 2 independent experiments.