Journal
JOURNAL OF IMMUNOLOGY
Volume 188, Issue 12, Pages 6046-6054Publisher
AMER ASSOC IMMUNOLOGISTS
DOI: 10.4049/jimmunol.1102760
Keywords
-
Categories
Funding
- National Institutes of Health [HL-69174, AI-40600-15]
- Clinical Translational Science Institute [UL1-RR024153]
Ask authors/readers for more resources
CCL11/eotaxin-1 is a potent eosinophilic CC chemokine expressed by primary human fibroblasts. The combination of TGF-beta 1 and IL-13 synergistically increases CCL11 expression, but the mechanisms behind the synergy are unclear. To address this, human airway fibroblast cultures from normal and asthmatic subjects were exposed to IL-13 alone or TGF-beta 1 plus IL-13. Transcriptional (nuclear run-on) and posttranscriptional (mRNA stability) assays confirmed that transcriptional regulation is critical for synergistic expression of CCL11. TGF-beta 1 plus IL-13 synergistically increased STAT-6 phosphorylation, nuclear translocation, and binding to the CCL11 promoter as compared with IL-13 alone. STAT-6 small interfering RNA significantly knocked down both STAT-6 mRNA expression and phosphorylation and inhibited CCL11 mRNA and protein expression. Regulation of the IL-4R alpha complex by TGF-beta 1 augmented IL-13 signaling by dampening IL-13R alpha 2 expression, overcoming IL-13's autoregulation of its pathway and enhancing the expression of CCL11. Our data suggest that TGF-beta 1 induced activation of the MEK/ERK pathway reduces IL-13R alpha 2 expression induced by IL-13. Thus, TGF-beta 1, a pleiotropic cytokine upregulated in asthmatic airways, can augment eosinophilic inflammation by interfering with IL-13's negative feedback autoregulatory loop under MEK/ERK-dependent conditions. The Journal of Immunology, 2012, 188: 6046-6054.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available