Dual-Specificity Phosphatase 1 and Tristetraprolin Cooperate To Regulate Macrophage Responses to Lipopolysaccharide

• Published in: The Journal of immunology (1950) Vol. 195; no. 1; pp. 277 - 288
• Main Authors: Smallie, Tim, Ross, Ewan A, Ammit, Alaina J, Cunliffe, Helen E, Tang, Tina, Rosner, Dalya R, Ridley, Michael L, Buckley, Christopher D, Saklatvala, Jeremy, Dean, Jonathan L, Clark, Andrew R
• Format: Journal Article
• Language: English
• Published: United States AAI 01.07.2015
• Subjects: Animals; Chemokine CXCL1 - genetics; Chemokine CXCL1 - immunology; Chemokine CXCL2 - genetics; Chemokine CXCL2 - immunology; Dual Specificity Phosphatase 1 - genetics; Dual Specificity Phosphatase 1 - immunology; Gene Expression Regulation; Immunity, Innate; Innate Immunity and Inflammation; Interleukin-10 - genetics; Interleukin-10 - immunology; Lipopolysaccharides - pharmacology; Macrophages - drug effects; Macrophages - immunology; Macrophages - pathology; MAP Kinase Kinase 4 - genetics; MAP Kinase Kinase 4 - immunology; Mice; Mice, Inbred C57BL; Mitogen-Activated Protein Kinase 11 - genetics; Mitogen-Activated Protein Kinase 11 - immunology; Mitogen-Activated Protein Kinase 14 - genetics; Mitogen-Activated Protein Kinase 14 - immunology; Phosphorylation; Primary Cell Culture; RNA Stability; RNA, Messenger - genetics; RNA, Messenger - immunology; Signal Transduction; Tristetraprolin - genetics; Tristetraprolin - immunology; Tumor Necrosis Factor-alpha - genetics; Tumor Necrosis Factor-alpha - immunology
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.1402830

Dual-specificity phosphatase (DUSP) 1 dephosphorylates and inactivates members of the MAPK superfamily, in particular, JNKs, p38α, and p38β MAPKs. It functions as an essential negative regulator of innate immune responses, hence disruption of the Dusp1 gene renders mice extremely sensitive to a wide variety of experimental inflammatory challenges. The principal mechanisms behind the overexpression of inflammatory mediators by Dusp1(-/-) cells are not known. In this study, we use a genetic approach to identify an important mechanism of action of DUSP1, involving the modulation of the activity of the mRNA-destabilizing protein tristetraprolin. This mechanism is key to the control of essential early mediators of inflammation, TNF, CXCL1, and CXCL2, as well as the anti-inflammatory cytokine IL-10. The same mechanism also contributes to the regulation of a large number of transcripts induced by treatment of macrophages with LPS. These findings demonstrate that modulation of the phosphorylation status of tristetraprolin is an important physiological mechanism by which innate immune responses can be controlled.