SHP-2 Phosphatase Negatively Regulates the TRIF Adaptor Protein-Dependent Type I Interferon and Proinflammatory Cytokine Production

Abstract

The Toll-like receptor 3 (TLR3) and TLR4-signaling pathway that involves the adaptor protein TRIF activates type I interferon (IFN) and proinflammatory cytokine expression. Little is known about how TRIF pathway-dependent gene expression is regulated. SH2-containing protein tyrosine phosphatase 2 (SHP-2) is a widely expressed cytoplasmic tyrosine phosphatase. Here we demonstrate that SHP-2 negatively regulated TLR4- and TLR3-activated IFN-beta production. SHP-2 inhibited TLR3-activated but not TLR2-, TLR7-, and TLR9-activated proinflammatory cytokine IL-6 and TNF-alpha production. SHP-2 inhibited poly(I:C)-induced cytokine production by a phosphatase activity-independent mechanism. C-terminal domain of SHP-2 directly bound TANK binding kinase (TBK1) by interacting with the kinase domain of TBK1. SHP-2 deficiency increased TBK1-activated IFN-beta and TNF-alpha expression. TBK1 knockdown inhibited poly(I:C)-induced IL-6 production in SHP-2-deficient cells. SHP-2 also inhibited poly(I:C)-induced activation of MAP kinase pathways. These results demonstrate that SHP-2 specifically negatively regulate TRIF-mediated gene expression in TLR signaling, partially through inhibiting TBK1-activated signal transduction.

Stk38 protein kinase preferentially inhibits TLR9-activated inflammatory responses by promoting MEKK2 ubiquitination in macrophages

“…Thioglycollate-elicited mouse peritoneal macrophages were isolated as previously described 31 .C57BL/6 mice (6-8 weeks old) were intraperitoneally injected with 2 ml3% sodiumthioglycollate (Sigma) solution each. Three days later, cells in the abdominal cavity were collected by lavaging with 10-15 ml DMEM without FBS and centrifugated.…”

“…The experiments were carried out as previously described 31 . Briefly, cells were lysed with M-PER Protein Extraction Reagent (Pierce) supplemented with protease inhibitor cocktail, and protein concentrations of the extracts were measured with BCA assay according to the manufacturer's instructions (Pierce).…”

Peroxisome Proliferator-activated Receptor γ Negatively Regulates IFN-β Production in Toll-like Receptor (TLR) 3- and TLR4-stimulated Macrophages by Preventing Interferon Regulatory Factor 3 Binding to the IFN-β Promoter

“…The primers used were PPAR␥-F, 5Ј-ATA-AGAATGCGGCCGCATGGTTGACACAGAGATGCC-3Ј and PPAR␥-R, 5Ј-GGGGTACCCTAATACAAGTCCTTGT-AGATCTCC-3Ј. IFN-␤ and IRF3 reporter plasmids were kind gifts from Dr. Cao Xuetao (14). The IRF3 reporter plasmids are composed of two plasmids, p-55UAS G Luc and p-EF-GAL4/IRF3, which were first described by Dr. Yoneyama (15).…”

MicroRNAs in the regulation of TLR and RIG-I pathways

“…4,5 Moreover, any dysregulation of this process has been associated with inflammatory diseases, autoimmune diseases or pathogen dissemination. Many molecules have been identified as positive or negative regulators of TLR signaling, 6,7 including phosphatases (SHP-1, SHP-2, SHIP-1, PTP1B, [8][9][10][11] etc. ), protein kinases (calmodulin-dependent protein kinase II, Btk, MEKK3, [12][13][14] etc.…”