Augmentation of LTC4 synthesis in human eosinophils caused by CD3-stimulated Th2-like cells in vitro

1 Section of Pulmonary and Critical Care Medicine, Department of Medicine, and 3 Committees on Clinical Pharmacology and Cell Physiology, Division of the Biological Sciences, and 2 Department of Pathology, University of Chicago, Chicago, Illinois 60637 We assessed the effect of anti-CD3-stimulated secretion of cultured human Th1- and Th2-like cells on leukotriene C 4 (LTC 4 ) secretion in isolated human eosinophils. T helper (Th) cell subsets were generated from human naive CD4 + T cells cocultured with irradiated human transformed B cells and either recombinant human interleukin (rhIL)-1 plus rhIL-6 plus rhIL-12 for Th1-like cells or rhIL-1 plus rhIL-6 plus rhIL-4 for Th2-like cells. Coincubation of eosinophils with 1:5 dilution of Th2-supernatant (Sup) caused an increase in LTC 4 secretion caused by 0.1 µM formyl-Met-Leu-Phe and 5 µg/ml cytochalasin B from 921 ± 238 to 3,067 ± 1,462 pg/10 6 eosinophils ( P