Granulocyte macrophage-colony-stimulating factor mRNA is stabilized in airway eosinophils and peripheral blood eosinophils activated by TNF-alpha plus fibronectin.
Airway eosinophils show prolonged in vitro survival compared with peripheral blood eosinophils (PBEos). Recent studies have shown that autocrine production and release of GM-CSF is responsible for enhanced survival, but the mechanisms controlling cytokine production remain obscure. We compared GM-CSF mRNA decay in eosinophils from bronchoalveolar lavage (BALEos) after allergen challenge or from PBEos. BALEos showed prolonged survival in vitro (60% at 4 days) and expressed GM-CSF mRNA. The enhanced survival of BALEos was 75% inhibited at 6 days by neutralizing anti-GM-CSF Ab. Based on transfection studies, GM-CSF mRNA was 2.5 times more stable in BALEos than in control PBEos. Treatment of PBEos with fibronectin and TNF-alpha increased their in vitro survival, GM-CSF mRNA expression, and GM-CSF mRNA stability to a comparable level as seen in BALEos. These data suggest that TNF-alpha plus fibronectin may increase eosinophil survival in vivo by controlling GM-CSF production at a posttranscriptional level.
Esnault
S
S
Department of Pathology, University of Wisconsin Medical School, Madison, WI 53792, USA.
Malter
J S
JS
D001980:Bronchi / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000166:cytology; D002465:Cell Movement / Q000276:immunology; D002470:Cell Survival / Q000187:drug effects / Q000276:immunology; D002478:Cells, Cultured; D004338:Drug Combinations; D004804:Eosinophils / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D005353:Fibronectins / Q000494:pharmacology*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000097:blood / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D012333:RNA, Messenger / Q000097:blood / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D015854:Up-Regulation / Q000276:immunology
D004338:Drug Combinations; D005353:Fibronectins; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D016178:Granulocyte-Macrophage Colony-Stimulating Factor