Allotype-dependent variations in cell surface HLA-B expression in TAP-deficient cells.

(A and B) Cell surface HLA-B levels in SK19 (TAP1-deficient) or STF1 (TAP2-deficient) cells infected with retroviral constructs encoding indicated HLA-B were expressed as mean fluorescence intensity (MFI) ratios relative to those obtained for infections with an empty retroviral vector lacking HLA-B (vec). Data are derived from 4–13 (A) or 2–9 (B) flow cytometric measurements with the W6/32 antibody following 2–5 (A) or 1–4 (B) separate retroviral infections. (C) The MFI ratios for HLA-B allotypes from SK19 cells (Panel A) correlate with those from STF1 cells (Panel B). (D) SK19 cells were also infected with retroviruses encoding HA-tagged versions of HLA-B (HA-HLA-B). Cell surface expression levels of HLA-B molecules were tested by flow cytometry after staining with anti-HA. Data are derived from 3 measurements following one infection. Significant differences are indicated (with an asterisk) on the graph (P<0.05). Statistical significance is based on an ordinary one-way ANOVA analysis with Fisher’s LSD test.