Figure 7.

NK cells preferentially lyse CD4 + T cells and not CD8 + T cells. Freshly purified CD4 + T and CD8 + T cells from healthy individuals were left untreated, treated with IL-2 (100 U/ml), or treated with a combination of IL-2 (100 U/ml) and anti-CD3 (1 µg/ml)/CD28mAb (3 µg/ml) for 18 h. NK cells which were treated and co-cultured with OCs as described in Fig. 1A, were used to determine cytotoxicity against CD4 + and CD8 + T cells using a TVA dye assay. LU 30/10⁷ cells were determined using the inverse of the number of NK cells required to lyse 30% of target cells × 1000 (n = 4) (A). NK cells were left untreated or treated with IL-2 (1000 U/ml) for 18 h, or expanded with OCs as described in Fig. 1A, and used to determine cytotoxicity against IL-2 (100 U/ml) and anti-CD3 (1 µg/ml)/CD28mAb (3 µg/ml) Treated CD4 + and CD8 + T cells using a TVA dye assay. LU 30/10⁷ cells were determined as described in Fig. 7A. One of several representative experiments is shown in the figures (B).