Inhibition of beryllium-induced IFN-γ expression with mAb’s to MHC class II molecules. (a) BAL cells from CBD patient 12 were cultured with BeSO₄ and increasing concentrations of mAb’s to HLA-DP, -DR, and -DQ. The data are presented as percent inhibition of IFN-γ expression. (b) Mean (± SEM) percent inhibition of beryllium-induced IFN-γ expression for the five CBD patients studied as shown in a.