Submitted on January 19, 2006
Revised on September 11, 2006
Beryllium-induced TNF-
Production is Transcription-Dependent in Chronic Beryllium Disease
Richard T Sawyer1*, Andrew P Fontenot2, Tristan A Barnes3, Charles E Parsons3, Brian C Tooker4, Lisa A Maier5, May M Gillespie3, E. Brigitte Gottschall5, Lori Silveira3, James Hagman6, and Lee S Newman5
1 Robert H. Hollis Laboratory of Environmental and Occupational Health, Division of Environmental and Occupational Sciences, Department of Medicine, National Jewish Medical and Research Center, Denver, CO, USA; Department of Medicine, Division of Pulmonary Science and Critical Care Medicine, University of Colorado Health Sciences Center, Denver, CO, USA,
2 Department of Medicine, Division of Pulmonary Science and Critical Care Medicine, University of Colorado Health Sciences Center, Denver, CO, USA; Integrated Department of Immunology, National Jewish Medical and Research Center, Denver, CO, USA; Department of Immunology, University of Colorado Health Sciences Center, Denver, CO, USA,
3 Robert H. Hollis Laboratory of Environmental and Occupational Health, Division of Environmental and Occupational Sciences, Department of Medicine, National Jewish Medical and Research Center, Denver, CO, USA,
4 Department of Medicine, Division of Pulmonary Science and Critical Care Medicine, University of Colorado Health Sciences Center, Denver, CO, USA,
5 Robert H. Hollis Laboratory of Environmental and Occupational Health, Division of Environmental and Occupational Sciences, Department of Medicine, National Jewish Medical and Research Center, Denver, CO, USA; Department of Medicine, Division of Pulmonary Science and Critical Care Medicine, University of Colorado Health Sciences Center, Denver, CO, USA; Department of Preventive Medicine and Biometrics, University of Colorado Health Sciences Center, Denver, CO, USA,
6 Integrated Department of Immunology, National Jewish Medical and Research Center, Denver, CO, USA
* To whom correspondence should be addressed. E-mail: sawyerr{at}niaid.nih.gov.
Beryllium (Be)-antigen presentation to Be-specific CD4+ T cells from the lungs of patients with chronic beryllium disease (CBD) results in T cell proliferation and TNF-
secretion. We tested the hypothesis that Be-induced, CBD BAL T cell, transcription-dependent, TNF- secretion was accompanied by specific transcription factor upregulation. After 6 hr of Be stimulation, CBD BAL cells produced a median of 883 pg/ml TNF- (range, 608-1275 pg/ml) versus 198 pg/ml (range, 116-245 pg/ml) by unstimulated cells. After 12 hr CBD BAL cells produced a median of 2963 pg/ml (range, 99 - 9424 pg/ml) TNF- versus 55 pg/ml (range, 0 - 454) by unstimulated cells. Using real time RT-PCR, Be-stimulated TNF- production at 6 hr was preceded by a 5-fold increase in TNF- pre-mRNA copy number:
actin copy number (Be median ratio 0.21; unstimulated median ratio 0.04). The median ratio of mature TNF- mRNA: actin mRNA was up-regulated 1.4-fold (Be median ratio 0.17; unstimulated median ratio 0.12). Be exposure in the presence of the transcription inhibitor pentoxifylline (PTX) decreased CBD BAL cell TNF- pre-mRNA levels > 60% whereas treatment with the mRNA splicing inhibitor 2-aminopurine (2AP) decreased levels 40% relative to Be exposure alone. PTX treatment decreased mature TNF- mRNA levels 50% while 2AP decreased levels > 80%, relative to Be exposure alone. Be exposure specifically up-regulated transcription factors AP-1 and NF-
B. The data suggest that Be exposure induces transcription-dependent TNF- production, potentially due to upregulation of specific transcription factors.
