Figure 3. Differential binding of OCH^HIGH and OCH^LOW iNKT cells to βGC-CD1d tetramers.

Ex vivo sorted human Vα24+/Vβ11+ iNKT clones were stained with different, α- or β-glycosylceramide loaded CD1d-tetramers. (A) A representative pair of CD4+ OCH^HIGH and OCH^LOW iNKT clones from one donor is shown. βGC-CD1d tetramers only stained OCH^HIGH but not OCH^LOW iNKT clones above background (as determined by PE-streptavidin binding). TCR Vα24 and Vβ11 surface expression levels for the two clones shown were very similar (for PE-conjugated anti-Vα24, MFI 2673 (OCH^HIGH) and 2710 (OCH^LOW); for FITC-conjugated anti-Vβ11, MFI 106 (OCH^HIGH) and 97 (OCH^LOW)). (B) βGC-CD1d tetramer staining intensity (MFI) of a panel of OCH-LOW (red markers), OCH-INT (green markers), and OCH-HIGH (blue markers) iNKT clones showed almost linear correlation with OCH-CD1d tetramer staining, but no correlation with either Vα24 or Vβ11 surface expression.