title: Human lung mast cells are enriched in the capacity to produce granulocyte-macrophage colony-stimulating factor in response to IgE-dependent stimulation.
abstract: By using reverse transcription-PCR, in situ hybridization, enzyme-linked immunosorbent assay and immunocytochemistry, we have studied the production of granulocyte-macrophage colony-stimulating factor (GM-CSF) in human lung mast cells induced by cross-linkage of high-affinity Fc epsilon receptors (Fc epsilonRI). We have also confirmed the bioactivity of GM-CSF released from lung mast cells by investigating the effect of the supernatant from lung mast cells activated with anti-IgE on the release of eosinophil cationic protein (ECP) from eosinophils. Mast cells were purified using affinity magnetic selection with monoclonal antibody (mAb) YB5.B8 (93-99% pure). Purified mast cells were precultured with IgE for 16 h before challenge with 1 microg/ml anti-IgE with or without stem cell factor (SCF). Eosinophils were purified by immunomagnetic negative selection (> 98% pure). The activation of mast cells via Fc epsilonRI enhanced the intensity of the GM-CSF signal within 2 h and the cells produced GM-CSF protein 4 h after the activation. In the absence of recombinant human (rh) SCF, anti-IgE induced a median GM-CSF response of 202 (< 15 to approximately 681) pg/10(6) mast cells/24 h, whereas in the presence of rhSCF the median IgE-dependent GM-CSF release was 356 (152 to approximately 1216) pg/10(6) mast cells/24 h. This difference was statistically significant (p = 0.0029, n = 12). In contrast, mast cells produced only a small amount of GM-CSF in the absence of anti-IgE. The mast cell supernatant induced ECP release from eosinophils and the release was significantly inhibited by blocking mAb against GM-CSF. These findings indicate that human mast cells are an important cellular source of GM-CSF and as such may contribute to chronic eosinophil-mediated inflammation.
authors.affiliation: The First Department of Internal Medicine, Gunma University Faculty of Medicine, School of Medicine, Maebashi, Japan. yokayama@sb.gunmau.ac.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Okayama
authors.forename: H
authors.initials: H
authors.lastname: Kobayashi
authors.forename: L K
authors.initials: LK
authors.lastname: Ashman
authors.forename: K
authors.initials: K
authors.lastname: Dobashi
authors.forename: T
authors.initials: T
authors.lastname: Nakazawa
authors.forename: S T
authors.initials: ST
authors.lastname: Holgate
authors.forename: M K
authors.initials: MK
authors.lastname: Church
authors.forename: M
authors.initials: M
authors.lastname: Mori
mesh_terms: D001798:Blood Proteins / Q000378:metabolism; D002474:Cell-Free System / Q000502:physiology; D047091:Eosinophil Granule Proteins; D004804:Eosinophils / Q000378:metabolism; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007073:Immunoglobulin E / Q000378:metabolism / Q000502:physiology*; D007700:Kinetics; D008168:Lung / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D008407:Mast Cells / Q000276:immunology / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D017455:Receptors, IgE / Q000502:physiology; D012260:Ribonucleases
chemical_list: D001798:Blood Proteins; D047091:Eosinophil Granule Proteins; D012333:RNA, Messenger; D017455:Receptors, IgE; D007073:Immunoglobulin E; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D012260:Ribonucleases