T reg cell depletion and reconstitution in DEREG mice and neutrophil depletion in Mrp8^+/+iDTR mice. (A) DEREG mice were treated with 1 µg DT i.p. and the T reg cell count was analyzed daily. Some mice were reconstituted with isolated T reg cells without iDTR at day 2 (data pooled from two independent experiments with 5–6 mice in each group; Mann-Whitney test was used for statistical analysis, *, P < 0.05). (B) DEREG mice were treated with 1 µg DT i.p. or vehicle control pulmonary neutrophil content after flushing out the pulmonary vasculature was analyzed at day 5 (data pooled from two independent experiments with five mice in each group; Mann-Whitney test was used for statistical analysis, *, P < 0.05). (C) WT platelets were incubated with vehicle or sCD40L (20 ng/ml) in vitro and platelet shape change after sCD40L stimulation was analyzed by light microscopy (exemplary images from three independent experiments with three samples in each group). Scale bar, 20 µm; lower inserts provide higher magnification of designated area. (D) Mrp8^+/+iDTR and Mrp8^−/−iDTR mice were treated with 1 µg DT i.p. and the neutrophil count in peripheral blood was analyzed daily (data pooled from two independent experiments with 5–6 mice in each group; Mann-Whitney test was used for statistical analysis, *, P < 0.05).