TNF-α increases stability of MHC class I complexes at the cell surface.

The presence of HLA class I at the cell surface of TNF-α–treated (▪) and control (○) cells was monitored at different time points (1 hour, 2 hours, 3 hours, 4 hours, 5 hours) after exposure to BFA. Level of MHC class I in the cell sample harvested at the end of BFA treatment is designated as time zero. MFI for each sample was calculated as the difference between the value obtained with W6/32 and isotype control antibody. Resultant intensity of fluorescence at each time point is shown as a percentage relative to the intensity of fluorescence at time zero (indicated as % MHC). (A) MHC class I stability at the cell surface of BL cell line. Results of 1 representative out of 3 performed experiments are shown. (B) MHC class I stability at the cell surface of 397 cell line. Results of 1 representative out of 4 experiments are shown.