Activation-induced T-cell death among normal human PBLs.

Freshly collected human PBLs were stimulated in 6-well plates in CM with PHA-P (5 μg/mL) and cultured for 5 days. Blasts cells were harvested and stained with CD3-FITC and PI, as indicated in “Materials and methods.” Ten thousand events were acquired in a FACSsort and analyzed using the Lysis II program. Results show dot blots (FCS vs SSC) before (upper dot blot) and 5 days after (lower dot blot) PHA activation. Histograms show the results of CD3 and PI staining of lymphoblasts in regions R1 and R2. Dotted lines represent background staining. Data from 1 of 5 separate experiments with similar results are shown.