NKR and NCR distribution in PBLs stimulated with HCMV-infected fibroblasts. PBLs from an HCMV⁺ donor were cocultured with mock- and Towne-infected (MOI = 1) MRC-5 cells. Cells harvested at day 11 were stained by indirect immunofluorescence with mAbs specific for different NKRs or NCRs, followed by labeling with anti-CD56-PE and -CD3-PerCP mAbs. Three-color flow cytometry analysis was carried out gating on CD3-CD56⁺ (A) and CD3⁺ (B) populations. The data are representative of 4 different experiments.