Differential expression of MHCII and CLIP on B and γδ T cells in response to FPI. (A) The mean fluorescence intensity (MFI), indicative of the level of cell surface expression of CLIP is significantly reduced on the surface of B cells at 24 hours after FPI. This reduction in CLIP likely reflects replacement of CLIP by other peptides. (B) Consistent with this interpretation, no corresponding significant decrease in the MFI of MHCII on the surface of B cells was observed at 24 hours after FPI. (C) In contrast, the MFI of CLIP on the surface of γδ T cells remained unchanged, (D) while the level of MHCII significantly decreased at 24 hours after FPI. Taken together, these data suggest that B cells are a likely candidate as APCs after FPI. Sham + vehicle (N = 6); FPI + vehicle (N = 7). The symbol * indicates P < 0.05.