Effects of interleukin-5 on acute myeloid leukemias.
Because of the known activity of interleukin-5 (IL-5) as a growth factor for human eosinophils, we performed studies to ascertain whether M4Eo acute leukemia cells might be capable of responding to IL-5. Surprisingly, short term incubation of freshly isolated M4Eo blasts with rhIL-5 induced differentiation of the cells to macrophages. To determine whether other variants of acute myelogenous leukemia (AML) might also be capable of responding to IL-5, we studied cells from four additional unselected cases and found that one responded to IL-5 by vigorous proliferation. Using biotinylated rhIL-5, second labelling with streptavidin-fluorescein isothiocyanate (FITC) and flow cytometric analysis, specific binding of IL-5 to both responsive leukemias was demonstrated, suggesting the presence of specific IL-5 receptors. Additional study will be needed to assess the frequency of IL-5 responsiveness in AML and to determine the relationship of these phenomena to the physiologic role of IL-5 in the regulation of hematopoiesis.
Baumann
M A
MA
Department of Medicine, VA Medical Center, Dayton, OH 45428.
Paul
C C
CC
Grace
M J
MJ
D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D004900:Erythroblasts / Q000187:drug effects / Q000473:pathology; D005434:Flow Cytometry; D016650:Fluorescein-5-isothiocyanate; D006801:Humans; D015848:Interleukin-5 / Q000494:pharmacology / Q000627:therapeutic use*; D015470:Leukemia, Myeloid, Acute / Q000097:blood*; D015479:Leukemia, Myelomonocytic, Acute / Q000097:blood*; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000473:pathology
D015848:Interleukin-5; D016650:Fluorescein-5-isothiocyanate