Granulocytes from B6 mice previously challenged with LPS or L monocytogenes in vivo do not express gzmB. Peritoneal exudate cells were derived from B6 and gzmB^-/- mice, either previously injected with LPS (2 μg; intraperitoneally), at 20 hours after infection (A) or previously infected intraperitoneally with L monocytogenes (5 × 10³ CFU), at 48 hours after infection (B), and analyzed (FACSCalibur) for the expression of Gr-1, NK1.1, Thy1.2, and Mac-1 and intracellularly for gzmB (αhugzmB mAb, 1:10), as described in “Materials and methods”; mouse IgG was used as isotype control, as described in “Materials and methods.” Numbers in graphs indicate the percentages of gated cells.