Smith, W.Guida, L.Qiuy, S.Korpelainen, E.van den Hueven, C.Gillis, D.Hawrylowicz, C.Vadas, M.Lopez, A.2006-07-052006-07-051995Blood, 1995; 86(10):3938-39440006-49711528-0020http://hdl.handle.net/2440/11539Freshly isolated peripheral blood neutrophils, unlike monocytes and eosinophils, do not bind interleukin-3 (IL-3) or respond to IL-3). We show that neutrophils cultured for 24 hours in granulocyte-macrophage colony-stimulating factor (GM-CSF) express mRNA for the IL-3 receptor (R) alpha subunit, as shown by RNase protection assays, and IL-3R alpha chain protein, as shown by cytometric analysis using two different specific monoclonal antibodies. This effect was selective for GM-CSF, because granulocyte colony-stimulating factor, tumor necrosis factor- alpha, interferon-gamma, and IL-1 failed to induce the IL-3 receptor. Saturation binding curves with 125I-IL-3 and Scatchard transformation showed the presence of about 100 high-affinity and 4,000 low-affinity receptors. Because neutrophils have been shown to express human leukocyte antigen (HLA)-DR in response to GM-CSF, we examined the possibility that IL-3 could augment HLA-DR expression on GM-CSF-treated cells. We found that neutrophils incubated with 30 ng/mL IL-3 as well as 0.1 ng/mL GM-CSF expressed a mean of 2.1-fold higher levels of HLA- DR than with GM-CSF alone (P < .005), confirming the signaling competence of the newly expressed IL-3R. This increase was seen even at maximal concentrations of GM-CSF and IL-3 can have an additive effect on mature human cells. The augmentation of HLA-DR by IL-3 was specific because it could be inhibited by a blocking anti-IL-3R antibody. Expression of class II molecules by neutrophils under these conditions may have significance for antigen presentation. These results provide further evidence for the role of GM-CSF as an amplification factor in inflammation by inducing neutrophil responsiveness to IL-3 produced by T cells or mast cells.en© 1995 by The American Society of HematologyNeutrophilsCells, CulturedHumansGranulocyte-Macrophage Colony-Stimulating FactorInterleukin-3Receptors, Granulocyte-Macrophage Colony-Stimulating FactorReceptors, Interleukin-3Recombinant ProteinsRNA, MessengerHLA-D AntigensFlow CytometrySignal TransductionNeutrophil ActivationGene Expression RegulationJournal article0030004250001995180010.1182/blood.v86.10.3938.bloodjournal86103938A1995TE585000382-s2.0-002885840668256Smith, W. [0000-0001-9640-1172] [0000-0002-4610-998X]Lopez, A. [0000-0001-7430-0135]