Figure 3. Efficient antigen presentation depends on a membrane-embedded inter-subunit salt bridge in the PLC.

(A) After nucleofection of TAP-deficient T2 cells with different combinations of TAP subunits as indicated, surface expression of MHC I was monitored by flow cytometry using the PE-coupled anti-human HLA-A/B/C antibody (W6/32). The horizontal line indicates surface expression mediated by TAP1/2. (B) Quantification of the MHC I surface expression (**P < 0.05, n = 3). Error bars indicate standard deviations. Statistical analysis was performed using t-test or one-way ANOVA. NS: not significant; mock; transfection with empty plasmid; iso: isotype control.