Comparative analysis of CD94/NKG2C and CD94/NKG2A expression in PBLs from healthy blood donors. (A) PBLs were stained with anti-NKG2A/C mAb (p25), NKG2A(Z199), and CD3 mAbs (Protocol 1; see “Immunofluorescence and flow cytometry analysis”). Samples were analyzed by flow cytometry and the proportions of NKG2A⁺ and NKG2C⁺ cells (p25⁺Z199^-) were calculated in total PBLs as well as in gated CD3⁺ and CD3^- populations. The staining patterns in samples from 2 different individuals (top and bottom histograms) representative of the variability in NKG2C expression are displayed. (B) PBLs stained with a combination of anti-NKG2A (Z199) and either NKG2A/C- (p25) or NKG2C-specific (MAB1381) mAbs were comparatively analyzed by flow cytometry. The staining patterns observed in 2 different individuals (top and bottom panels) are displayed. Numbers within the plots correspond to the percentage of NKG2C⁺ cells.