Selective stimulation of L-selectin shedding on eosinophils by PGD₂.

L-selectin expression was measured in eosinophils (A) and neutrophils (B) by a method analogous to that illustrated in Figure 2, except that FITC-labeled anti– L-selectin was used instead of FITC-labeled anti-CD11b. The results are expressed as the percentages of L-selectin that were shed following incubation with PGD₂ (●), 5-oxo-ETE (○, 5o-ETE), and PGE₂ (▿). The values obtained for unstimulated control cells were assumed to represent no shedding of L-selectin, whereas the values obtained following labeling with an FITC-labeled isotype control antibody were taken to be equivalent to complete shedding of L-selectin from the surface of the cell. All values are means ± SE of determinations on leukocytes from 4 individuals.