RIT HLA-B allotypes of the Bw4 group are more efficient in inhibiting KIR3DL1⁺ NK cell activation in the presence of the viral TAP inhibitor BNLF2a.

HLA-I deficient K562 cells infected with retrovirus encoding exogenous HLA-B*44:03 and HLA-B*57:03 or retrovirus lacking HLA-B (vector) were chosen and further infected with a BNLF2a-encoding retrovirus or retrovirus lacking BNLF2a (vector). Intracellular BNLF2a expression levels (A) and cell surface expression of HLA-B were assessed by flow cytometry (B). HLA-B*44:03 expression is more strongly reduced by BNLF2a than HLA-B*57:03 (one representative experiment of three measurements is shown). (C) K562 cell based NK cell activation assay was performed with PBMCs from three different donors (D187, D136 and D215). CD3^-CD56⁺KIR3DL1⁺ cells were gated and NK cell activation was assessed by quantifying IFN-γ expressing population. One representative dataset from two experiments is shown.