Figure 8.

Antibodies to CD54 or LFA-1 was unable to reverse differentiation but inhibited moderately the cytotoxicity of NKs against differentiated OSCSCs. Highly purified NK cells were left untreated or treated with the combination of IL-2 (1000 units/ml) and anti-CD16 mAb (3 μg/ml) for 24 h, after which the same amounts of supernatants were removed and added to the OSCSCs in the presence and absence of anti-CD54 mAb (10 μg/ml) (A) and anti-LFA-1 (1:100) (B) for 5 days. Treated OSCSCs were then washed extensively and used in a standard 4 h ⁵¹Cr release assay against IL-2-activated (1000 units/ml) NK cells. Pre-treatment of NK cells with IL-2 were carried out for 18–24 h. Percent cytotoxicity was determined at different effector to target ratio, and the lytic units 30/10⁶ cells were determined using inverse number of NK cells required to lyse 30% of the tumor cells ×100.