Figure 6.

TGF-β and Fas ligand induced eosinophil apoptosis but did not activate CoA-IT. (A) Human eosinophils cultured with TGF-β (500 pg/ml) for 0 to 96 hours were assayed by arachidonic acid transfer to radiolabeled lyso-PAF, and CoA-IT hydrolytic activity calculated as a percent of control. CoA-IT enzymatic activity (circles) was measured for times from 0 to 72 hours. Eosinophil apoptotic characteristics were also determined including phosphatidylserine exposure (open diamonds), cell volume reduction (open squares), morphologic changes (solid squares), and membrane integrity (solid diamonds) by trypan blue exclusion. Data are the average of three to eight experiments per assay. (B) Human eosinophils cultured with anti-Fas (100 ng/ml), which acts as a Fas ligand, and were measured for CoA-IT hydrolytic activity (circles) out to 72 hours. Apoptotic characteristics were also determined including phosphatidylserine exposure (open diamonds), cell volume reduction (open squares), morphologic changes (solid squares), and membrane integrity (solid diamonds) by trypan blue exclusion. Data are the average of three to nine experiments per assay.