Release of IFN-γ and TNF-α in the cytotoxicity assay.

The concentrations of IFN-γ (A) and TNF-α (B) as indicators of NK activation were determined by ELISA in the culture supernate. NK cells were isolated from peripheral blood of 5 healthy volunteers and cocultured for up to 12 hours with K562 cells with (▪) and without (■) PIG-A mutation in the absence of IL-2. E/T ratio was 32:1. A and B show the data of representative of 5 donors. Each value represents the mean (± SD) of triplicate assays.