Figure 3. Proteasomal activity is required for stable surface K^b expression in TAP1^−/− dendritic cells and antigen cross‐presentation.

• A–D
  TAP1^−/− BMDC transduced with vector control (A) or hβ₂m (C) were incubated with varying concentrations of epoxomicin for 6 h in the absence or presence of exogenously added K^b‐binding SIINFEKL peptide and analyzed for surface expression of K^b by flow cytometry. Representative plots are shown (A, C). The impact of epoxomicin on cell surface K^b was analyzed by plotting K^b surface expression on cells incubated with epoxomicin, normalized to that on cells incubated without epoxomicin (n = 3) (B, D).
• E
  The effect of epoxomicin on cross‐presentation of OVA‐coated beads by TAP1^−/− BMDC expressing hβ₂m was determined by incubating the BMDC with OVA‐coated latex beads in the presence of varying doses of epoxomicin and 10 μM gB peptide. After 6 h, the cells were fixed and incubated with B3Z cells and IL‐2 production was measured.

Data information: In (B, D), the means (±SEM) of three independent experiments are plotted. Data were analyzed by performing a non‐linear regression analysis. In (E), a representative experiment of three independent experiments is shown. The mean (±SD) of assay triplicates is plotted. Data were analyzed by performing a linear regression analysis.