TAP1-dependencies of HLA-B expression.

<p>(A) Cells from one infection from <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1007171#ppat.1007171.g001" target="_blank">Fig 1A</a> were subsequently infected with a TAP1-encoding retrovirus. The MFI ratios in the presence and absence of TAP1 (+TAP1/-TAP1) were calculated for each HLA-B–expressing cell line (n = 4 analyses from one infection). (B) Correlation between surface HLA-B expression in SK19 cells (calculated from <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1007171#ppat.1007171.g001" target="_blank">Fig 1A</a>) and their +TAP1/-TAP1 MFI ratios (calculated from Fig 2A). (C) Cells from the infections shown in <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1007171#ppat.1007171.g001" target="_blank">Fig 1D</a> were subsequently infected with a TAP1-encoding retrovirus. The MFI ratios in the presence and absence of TAP1 (+TAP1/-TAP1) were calculated for each HA-HLA-B–expressing cell line (n = 4 analyses from one infection). (D) Parental and TAP1-knockdown Hela cells (Hela-TAP1-KD) were assessed by immunoblotting with the anti-TAP1 antibody 148.3 (inset panel; 5, 10 or 20 μg of cell lysate was loaded in each lane) and infected with retroviruses encoding HLA-B allotypes or a control retrovirus (vector). TAP1 expression levels were measured by flow cytometry after intracellular staining with 148.3 antibody. (E) HLA-B expression levels at the surface of Hela or Hela-TAP1-KD cells were measured after W6/32 staining. The MFI ratios (Hela-TAP1-KD/Hela) were calculated for each HLA-B–expressing cell line (n = 6–7 measurements from three separate infections of Hela or Hela-TAP1-KD cells with retroviruses encoding indicated HLA-B). Significant differences are indicated (with an asterisk) on the graph (<i>P</i><0.05). Statistical significance is based on an ordinary one-way ANOVA analysis with Fisher’s LSD test.</p>