Fig. 3.
HBenvAg-specific intracellular cytokine production.
HBenvAg-stimulated or unstimulated PBMCs obtained from 1 representative XLA patient (patient 2) and 1 control subject and assayed by flow cytometry, are shown. Analysis was performed 24 months after the last anti-HBV vaccine boost. PBMCs were cultured with 10 μg/mL HBenvAg for 18 hours at 37°C, 5% CO2; at 2 hours after cultures were started, brefeldin-A was added. Fixed and permeabilized cells were triple stained with anti-CD4, anti–IFN-γ, and anti–IL-4 as described in “Patients, materials, and methods.” Cells were gated according to CD4 expression, and data are represented as IL-4–producing cells on the x-axis and IFN-γ–producing cells on the y-axis. The percentage of either single- or double-positive cells is indicated in the respective plot quadrants. Pt indicates patient.