Differentiation of a Human Eosinophilic Leukemia Cell Line (EoL-1) by a Human T-Cell Leukemia Cell Line (HIL-3)-Derived Factor

Abstract

AbstractDifferentiation of a human eosinophilic leukemia cell line, EoL-1, induced by the culture supernatant of a human ATL cell line, HIL-3 (HIL-3 sup) was compared with differentiation induced by defined cytokines. HIL-3 sup induced EoL-1 cells to express eosinophilic granules and segmented nuclei after 6 to 9 days of incubation. HIL-3 sup also induced the expression of Fce receptor II (Fce RM/CD23) and an eosinophil differentiation antigen EO-1 mainly on eosinophilic granule (+) cells. Furthermore, HIL-3 sup induced EoL-1 cells to respond to an eosinophil chemotactic factor, platelet activating factor. HIL-3 cells express messenger RNA (mRNA) of interleukin-5 (IL-5), macrophage colony-stimulating factor (M-CSF), and IL-3 but not granulocyte CSF (G-CSF). Granulocyte-macrophage CSF (GM-CSF) and tumor necrosis factor-α (TNF-α) were detected in the HIL-3 sup. Recombinant IL-2 (rlL-2), rlL-3, rlL-4, rlL-5, rM-CSF, and rGM-CSF did not induce eosinophilic granules. rG-CSF induced a few eosinophilic granule (+) cells, and TNF-α, which did not induce eosinophilic granules by itself, enhanced the ability of G-CSF to induce them. However, G-CSF and TNF-α did not induce the expression of FceRII and EO-1 antigen. Moreover, anti-G-CSF, anti-TNF-α, anti-GM-CSF, anti-IL-3, and anti-IL-5 antibodies did not suppress the effect of HIL-3 sup on the differentiation of EoL-1 cells. All the data suggest that HIL-3 sup contains an unidentified factor that induces differentiation of EoL-1 cells, and that EoL-1 cells and HIL-3 sup provide an important model for the examination of differentiation mechanisms and functions of eosinophils.