FIG. 6.

Effect of anti-human CD70 MAb on the growth and viability of ATL cells. (A) S1T (diamonds) and MOLT-4 (squares) cells were incubated with an anti-CD70 MAb (filled symbols) or its isotype-matched control MAb (open symbols) at a concentration of 1 μg/ml. After a 4-day incubation, the number of viable cells was determined by trypan blue exclusion. (B) PBMCs obtained from three different ATL patients (circles, squares, and diamonds) were incubated with an anti-CD70 MAb (closed symbols) or its isotype-matched control MAb (open symbols) at various concentrations. After a 24-h incubation, the number of viable cells was determined by the MTT method. Error bars indicate standard deviations.