Frequency and intensity of KIR expression as a function of the presence of MHC class I ligands.

Comparison of the frequency (A) and the mean fluorescence intensity (B) of KIR3DL01 staining on NK cells prior to SIV infection versus the number of MHC class I alleles predicted to encode Mamu-Bw4 ligands for this receptor by linear regression analysis. Comparison of the frequency (C) and the mean fluorescence intensity (D) of KIR3DL05 staining on NK cells for Mamu-A1*002^-, -A3*13^- (open circle), Mamu-A1*002^-, -A3*13⁺ (red dot), Mamu-A1*002⁺, -A3*13^- (black dot), and Mamu-A1*002⁺, -A3*13⁺ (black circle, red dot) animals prior to SIV infection by linear regression analysis. Comparison of the frequency (E) and the mean fluorescence intensity (F) of KIR3DL05 staining on NK cells for Mamu-A1*002⁺ (blue) versus -A1*002^- (red) animals at the indicated time points before and after SIV infection. Significant differences are indicated with asterisks (p<0.05* & p<0.01**, Mann-Whitney U-test).