Cell death did not occur in PBMCs regardless of activation with PMA and ionomycin.

<p><b>A</b>) Representative DAPI staining images showing that the bacteria induced cell death in immortal Jurkat cells, but not in primary PBMCs. Data was estimated at 24 h after incubation. Magnification, ×1,000. <b>B and C</b>) Time-course changes of the percentage of dead PBMCs with (C) or without (B) PMA and ionomycin. PBMC cell death prevalence was estimated using a trypan blue exclusion assay. The plot shown represents the mean value of the data from individual donors performed in duplicate. The averages in parentheses at each time point are compared. *, <i>p</i><0.05; significantly different from each average for the “without treatment group” at each of the time points after incubation.