Surface markers expressed by BAL CD4⁺ T cells from CBD patients. (a) The percentage of BAL CD4⁺ T cells that express CD45RO, CD62L, CD11a, and CCR7 is shown. The symbols for each CBD patient correspond to those shown in Figures 4 and 6, and the solid line represents the mean value for each marker. (b) Intracellular IFN-γ production by BAL CD4⁺ T cells in relation to expression of CCR7 following stimulation with medium alone or SEB. Data are shown for the percentage of BAL CD4⁺ T cells that express IFN-γ, CCR7, or both. (c) IFN-γ and IL-2 production by BAL CD4⁺ T cells in relation to expression of CCR7 following stimulation with BeSO₄. Data are shown for the percentage of BAL CD4⁺ T cells that express IFN-γ, CCR7, or both.