Figure 4.

CD8 is not a cytotoxic triggering molecule on freshly purified or IL-2-stimulated NK cells. Neither freshly isolated NK cells at various effector : target ratios (a) nor IL-2-activated NK cells at an effector : target ratio of 5 : 1 (b) were triggered by either anti-CD8 (RPA-T8) or anti-CD8 (OKT8) to mediate reverse ADCC of P815 target cells (a kind gift from Prof. M. Glennie, University of Southampton). Anti-CD16 (3G8), was used as a positive control. Asterisks indicate results which are significantly greater (P < 0·05) than the background NK lysis in the absence of mAb.