Figure 6. Identification of the m138 domains involved in the downmodulation of ICOSL and CD80.

(A) Schematic representation (not drawn to scale) of m138-GFP protein mutants. (B) NIH3T3 ICOSL-HA cells were untransfected or transfected with m138-GFP, or m138-GFP mutant constructs and analyzed by flow cytometry for ICOSL and CD80 surface levels. Panels on the right represent the MFI of each sample minus the MFI of the control isotypes. Gray histograms represent the expression of untransfected cells and colored histograms represent the expression of cells transfected with m138-GFP (green), m138∆Ig1-GFP (brown), m138∆Ig2-GFP (blue), or m138∆Ig2/3-GFP (red). The isotype for each antibody was used as a negative control (dotted lines). A representative experiment out of two performed is shown.