FIG. 10.

The substitution of residues 97 and 99 of CCMV US6 with aspartate residues enhances the ability of CCMV US6 to inhibit cell surface expression of HLA-B2705. (A) Schematic representation of the amino acid amino acid substitutions introduced into CCMV US6 to generate the CCMV US6 N97D/S99D mutant. The schematic representations are set up as described in the legend to Fig. 3. (B) Analysis of the effect of the CCMV US6 N97D/S99D mutant on the cell surface expression of HLA-B2705. HeLa-M cells were either transfected with a control vector or cotransfected with a control vector and the HLA-B2705 expression construct or cotransfected with HLA-B2705 and each US6 construct. To detect HLA-B2705 expression, the transfectants were stained with the ME1 MAb and a Cy5-conjugated secondary antibody; antibody fluorescence was quantified by flow cytometry. The level of HLA-B2705 expression is expressed as a percentage of the MFV of the positive control (cells transfected with HLA-B2705 and control vector) after subtracting the MFV of the negative control (cells transfected with control vector only). Each bar represents the mean level of HLA-B2705 expression calculated from four independent experiments. Error bars show the standard deviations. Statistical analysis was performed using the Mann-Whitney U test.