In:
Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 102, No. 44 ( 2005-11), p. 16001-16006
Abstract:
A member of the IFN regulatory factor (IRF) family of transcription factors, IRF-4 is expressed in lymphocytes and macrophage/dendritic cells. Studies using IRF-4-deficient mice have revealed the critical roles of IRF-4 in lymphocyte responses. However, the role of IRF-4 in innate immune responses is not clearly understood. Here, we demonstrate that IRF-4 negatively regulates the production of proinflammatory cytokines by macrophages in response to Toll-like receptor (TLR) stimulation. Mice lacking IRF-4 are sensitive to LPS-induced shock, and their macrophages produce high levels of proinflammatory cytokines, including TNF-α and IL-6, in response to TLR ligands. The inhibitory role of IRF-4 in response to TLR stimulation was confirmed by the down-regulation of IRF-4 expression in normal macrophages by using the small interfering RNA technique and by the overexpression of IRF-4 in macrophage line RAW264.7. Activation of the important signaling pathways for cytokine production, NF-κB and JNK (c-Jun N-terminal kinase), was enhanced after LPS stimulation in IRF-4 -/- macrophages. These results imply that IRF-4 negatively regulates TLR signaling and is inhibitory to the production of proinflammatory cytokines in response to TLR stimulation.
Type of Medium:
Online Resource
ISSN:
0027-8424
,
1091-6490
DOI:
10.1073/pnas.0504226102
Language:
English
Publisher:
Proceedings of the National Academy of Sciences
Publication Date:
2005
detail.hit.zdb_id:
209104-5
detail.hit.zdb_id:
1461794-8
SSG:
11
SSG:
12