Journal
JOURNAL OF IMMUNOLOGY
Volume 195, Issue 8, Pages 3849-3857Publisher
AMER ASSOC IMMUNOLOGISTS
DOI: 10.4049/jimmunol.1403083
Keywords
-
Categories
Funding
- National Natural Science Foundation of China [81170084, 31270943, 81373146, 81422021]
- Shanghai Rising-Star Program [13QA1403100, 14QA1404600]
- Basic Research Program of Science and Technology Commission of Shanghai Municipality [14JC1405200]
- Foundation for the Author of National Excellent Doctoral Dissertation of People's Republic of China
- Doctor Science Research Foundation of the Education Ministry of China [20130072120062]
Ask authors/readers for more resources
The effective recognition of viral infection and subsequent type I IFN production is essential for the host antiviral innate immune responses. The phosphorylation and activation of kinase TANK-binding kinase 1 (TBK1) plays crucial roles in the production of type I IFN mediated by TLR and retinoic acid-inducible gene I-like receptors. Type I IFN expression must be tightly regulated to prevent the development of immunopathological disorders. However, how the activated TBK1 is negatively regulated by phosphatases remains poorly understood. In this study, we identified a previously unknown role of protein phosphatase (PP)4 by acting as a TBK1 phosphatase. PP4 expression was upregulated in macrophages infected with RNA virus, vesicular stomatitis virus, and Sendai virus in vitro and in vivo. Knockdown of PP4C, the catalytic subunit of PP4, significantly increased type I IFN production in macrophages and dentritic cells triggered by TLR3/4 ligands, vesicular stomatitis virus, and Sendai virus, and thus inhibited virus replication. Similar results were also found in peritoneal macrophages with PP4C silencing in vivo and i.p. infection of RNA virus. Accordingly, ectopic expression of PP4C inhibited virus-induced type I IFN production and promoted virus replication. However, overexpression of a phosphatase-dead PP4C mutant abolished the inhibitory effects of wild-type PP4C on type I IFN production. Mechanistically, PP4 directly bound TBK1 upon virus infection, then dephosphorylated TBK1 at Ser(172) and inhibited TBK1 activation, and subsequently restrained IFN regulatory factor 3 activation, resulting in suppressed production of type I IFN and IFN-stimulated genes. Thus, serine/threonine phosphatase PP4 functions as a novel feedback negative regulator of RNA virus-triggered innate immunity.
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