title: Identification of the major activity derived from cultured human peripheral blood mononuclear cells, which enhances eosinophil viability, as granulocyte macrophage colony-stimulating factor (GM-CSF).
abstract: Eosinophils (EOSs) cultured in the presence of 50% peripheral blood mononuclear cell (PBMC)-derived culture supernatants remained 67% +/- 7% (mean +/- SEM; n = 5) viable for 7 days. In the absence of PBMC supernatant, only 15% +/- 7% of cells remained viable for 7 days. PBMC supernatants from six atopic individuals, with eosinophilia, and six normal subjects, with no eosinophilia, were compared for EOS viability-enhancing activity with the same target EOSs. Optimal conditions for the production of viability-enhancing activity by mononuclear cells were established as a 24-hour culture period, with a concentration of 2 x 10(6) cells per milliliter. Comparison of monocyte-enriched and lymphocyte-enriched culture supernatants for the production of the EOS viability-enhancing activity indicated that both cell types released the factor. C-18 Sep-Pak separation of the PBMC culture supernatant yielded a major EOS viability-enhancing activity in the aqueous eluent, suggesting a hydrophilic molecule. This major activity was neutralized by a specific antibody to granulocyte/macrophage colony-stimulating factor but was unaffected by specific antibodies to interleukin-3 and interleukin-5. A second, minor viability-enhancing activity was observed in the 100% methanol fraction, indicating the presence of a more hydrophobic molecule. The supernatants from the PBMCs of the atopic individuals consistently enhanced EOS survival to a greater extent than supernatants from the PBMCs of the normal, nonatopic individuals.
authors.affiliation: Department of Allergy and Allied Respiratory Disorders, United Medical School, Guy's Hospital, London, England.
authors.forename: L A
authors.initials: LA
authors.lastname: Burke
authors.forename: M P
authors.initials: MP
authors.lastname: Hallsworth
authors.forename: T M
authors.initials: TM
authors.lastname: Litchfield
authors.forename: R
authors.initials: R
authors.lastname: Davidson
authors.forename: T H
authors.initials: TH
authors.lastname: Lee
mesh_terms: D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004804:Eosinophils / Q000187:drug effects*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000302:isolation & purification* / Q000494:pharmacology; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology; D007963:Leukocytes, Mononuclear / Q000737:chemistry*; D008214:Lymphocytes / Q000737:chemistry; D009000:Monocytes / Q000737:chemistry
chemical_list: D016178:Granulocyte-Macrophage Colony-Stimulating Factor