FIG 3.

BDLF3 induces downregulation of all HLA class I and class II alleles. (A) The MHC class I-negative cell line K562, transduced to stably express either HLA-A2, -B35, or -Cw1, was electroporated with the control-GFP or BDLF3-GFP plasmid. At 24 h posttransfection, two-color flow cytometry was used to measure surface MHC class I levels in the GFP⁺ populations in the control-GFP-transfected cells (solid lines) and BDLF3-GFP-transfected cells (dashed lines). (B) HEK-293 cells stably expressing CIITA were transiently transfected with the control-GFP or BDLF3-GFP plasmid. At 24 h posttransfection, two-color flow cytometry was used to measure surface HLA-DR and HLA-DQ levels in GFP⁺ populations in the control-GFP-transfected cells (solid lines) and the BDLF3-GFP-transfected cells (dashed lines). The gray histograms denote background staining obtained with an isotype control antibody.