Time course of lymphoma cell permeabilization and phagocytosis following H₂O₂ treatment.

JLP 119 cells (A) or BL-41 cells (B) were treated with 75 or 250 μmol/L H₂O₂, respectively, and allowed to incubate for the times indicated in the figure. Cells were then harvested and incubated with monocyte-derived macrophages for 1 hour. Percent phagocytosis (open circles) was analyzed as described in “Materials and methods.” Cell death was quantified by Hoechst/PI staining. The total percentage of cells that had become permeable to PI is shown (closed circles). Under these conditions, at least 82% of the PI-permeable cells at each time point were pyknotic/necrotic. The results for JLP 119 are averaged from 2 separate experiments, and those for BL-41 are from a single experiment.