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STING Negatively Regulates Double-Stranded DNA-Activated JAK1-STAT1 Signaling via SHP-1/2 in B Cells.

Dong G, You M, Ding L, Fan H, Liu F, Ren D, Hou Y - Mol. Cells (2015)

Bottom Line: In the present study, we found that dsDNA directly triggered the JAK1-STAT1 signaling by inducing phosphorylation of the Lyn kinase.Moreover, this response is not dependent on type I IFN receptors.In addition, compared with normal B cells, the expression of STING was significantly lower and the phosphorylation level of JAK1 was significantly higher in B cells from MRL/lpr lupus-prone mice, highlighting the close association between STING low-expression and JAK1-STAT1 signaling activation in B cells in autoimmune diseases.

View Article: PubMed Central - PubMed

Affiliation: The State Key Laboratory of Pharmaceutical Biotechnology, Division of Immunology, Medical School, Nanjing University, Nanjing 210093, China.

ABSTRACT
Recognition of cytosolic DNA initiates a series of innate immune responses by inducing IFN-I production and subsequent triggering JAK1-STAT1 signaling which plays critical roles in the pathogenesis of infection, inflammation and autoimmune diseases through promoting B cell activation and antibody responses. The stimulator of interferon genes protein (STING) has been demonstrated to be a critical hub of type I IFN induction in cytosolic DNA-sensing pathways. However, it still remains unknown whether cytosolic DNA can directly activate the JAK1-STAT1 signaling or not. And the role of STING is also unclear in this response. In the present study, we found that dsDNA directly triggered the JAK1-STAT1 signaling by inducing phosphorylation of the Lyn kinase. Moreover, this response is not dependent on type I IFN receptors. Interestingly, STING could inhibit dsDNA-triggered activation of JAK1-STAT1 signaling by inducing SHP-1 and SHP-2 phosphorylation. In addition, compared with normal B cells, the expression of STING was significantly lower and the phosphorylation level of JAK1 was significantly higher in B cells from MRL/lpr lupus-prone mice, highlighting the close association between STING low-expression and JAK1-STAT1 signaling activation in B cells in autoimmune diseases. Our data provide a molecular insight into the novel role of STING in dsDNA-mediated inflammatory disorders.

No MeSH data available.


Related in: MedlinePlus

Low-expression of STING in B cells from patients with SLE and MRL/lpr mice. (A) FACS analysis of STING expression in B cells from patients with SLE (n = 8) and healthy donors (n = 8). (B) qPCR analysis of the expression of STING in B cells from MRL/lpr mice (n = 9) and wild-type mice (n = 10). (C) B cells were isolated from spleen of MRL/lpr mice (n = 6) and wild-type mice (n = 6). Western blot analysis of the phosphorylation levels of SHP-1/2 and JAK1. (D) BJAB cells were transfected with poly(dA:dT) for 8 h,16 h and 24 h. The expression of STING was analyzed by qPCR. (E) Isolated human CD19+ B cells were stimulated with TLR7 ligand R848 (1 μg/ml), TLR9 ligand CpG2006S (0.5 μM), human anti-IgM (10 μg/ml) and human IFN-α (1,000 U/ml) for 8 h and 16 h. The expression of STING was detected by qPCR. (F) Isolated murine splenic B cells were stimulated with TLR7 ligand R848 (1 μg/ml), TLR9 ligand CpG1826 (0.5 μM), mouse anti-IgM (10 μg/ml) and mouse IFN-α (1,000 U/ml) for 8 h and 16 h. The expression of STING was detected by qPCR. (G) Proposed regulatory pathway activated by dsDNA in B cells. The data shown represent the means of three independent experiments, and the error bars represent the s.e.m. *p < 0.05, **p < 0.01, ***p < 0.001; ns denotes p > 0.05.
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f5-molce-38-5-441: Low-expression of STING in B cells from patients with SLE and MRL/lpr mice. (A) FACS analysis of STING expression in B cells from patients with SLE (n = 8) and healthy donors (n = 8). (B) qPCR analysis of the expression of STING in B cells from MRL/lpr mice (n = 9) and wild-type mice (n = 10). (C) B cells were isolated from spleen of MRL/lpr mice (n = 6) and wild-type mice (n = 6). Western blot analysis of the phosphorylation levels of SHP-1/2 and JAK1. (D) BJAB cells were transfected with poly(dA:dT) for 8 h,16 h and 24 h. The expression of STING was analyzed by qPCR. (E) Isolated human CD19+ B cells were stimulated with TLR7 ligand R848 (1 μg/ml), TLR9 ligand CpG2006S (0.5 μM), human anti-IgM (10 μg/ml) and human IFN-α (1,000 U/ml) for 8 h and 16 h. The expression of STING was detected by qPCR. (F) Isolated murine splenic B cells were stimulated with TLR7 ligand R848 (1 μg/ml), TLR9 ligand CpG1826 (0.5 μM), mouse anti-IgM (10 μg/ml) and mouse IFN-α (1,000 U/ml) for 8 h and 16 h. The expression of STING was detected by qPCR. (G) Proposed regulatory pathway activated by dsDNA in B cells. The data shown represent the means of three independent experiments, and the error bars represent the s.e.m. *p < 0.05, **p < 0.01, ***p < 0.001; ns denotes p > 0.05.

Mentions: Since STING plays a negative role in dsDNA-triggered activation of JAK1-STAT1 signaling in B cells, we next detected the expression of STING in B cells from patients with SLE and MRL/lpr mice. PBMCs from patients with SLE and healthy donors were collected and the expression of STING in CD19+ B cells was detected by intracellular FACS analysis. As shown in Fig. 5A, patients with SLE showed a lower expression level of STING in B cells compared with healthy donors. We also detected the expression of STING in splenic B cells from MRL/lpr mice and wild-type mice by qPCR. Consistently, MRL/lpr mice showed a lower expression level of STING (Fig. 5B). These results demonstrate that the expression of STING is down-regulated in B cells from patients with SLE and MRL/lpr mice. Furthermore, we detected the phosphorylation of JAK1, SHP-1 and SHP-2 in B cells isolated from spleen of MRL/lpr mice and wild-type mice. Intriguingly, compared with wild-type mice, MRL/lpr mice showed a significantly higher level of p-JAK1 and lower phosphorylation levels of SHP-1 and SHP-2 in B cells (Fig. 5C).


STING Negatively Regulates Double-Stranded DNA-Activated JAK1-STAT1 Signaling via SHP-1/2 in B Cells.

Dong G, You M, Ding L, Fan H, Liu F, Ren D, Hou Y - Mol. Cells (2015)

Low-expression of STING in B cells from patients with SLE and MRL/lpr mice. (A) FACS analysis of STING expression in B cells from patients with SLE (n = 8) and healthy donors (n = 8). (B) qPCR analysis of the expression of STING in B cells from MRL/lpr mice (n = 9) and wild-type mice (n = 10). (C) B cells were isolated from spleen of MRL/lpr mice (n = 6) and wild-type mice (n = 6). Western blot analysis of the phosphorylation levels of SHP-1/2 and JAK1. (D) BJAB cells were transfected with poly(dA:dT) for 8 h,16 h and 24 h. The expression of STING was analyzed by qPCR. (E) Isolated human CD19+ B cells were stimulated with TLR7 ligand R848 (1 μg/ml), TLR9 ligand CpG2006S (0.5 μM), human anti-IgM (10 μg/ml) and human IFN-α (1,000 U/ml) for 8 h and 16 h. The expression of STING was detected by qPCR. (F) Isolated murine splenic B cells were stimulated with TLR7 ligand R848 (1 μg/ml), TLR9 ligand CpG1826 (0.5 μM), mouse anti-IgM (10 μg/ml) and mouse IFN-α (1,000 U/ml) for 8 h and 16 h. The expression of STING was detected by qPCR. (G) Proposed regulatory pathway activated by dsDNA in B cells. The data shown represent the means of three independent experiments, and the error bars represent the s.e.m. *p < 0.05, **p < 0.01, ***p < 0.001; ns denotes p > 0.05.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4443286&req=5

f5-molce-38-5-441: Low-expression of STING in B cells from patients with SLE and MRL/lpr mice. (A) FACS analysis of STING expression in B cells from patients with SLE (n = 8) and healthy donors (n = 8). (B) qPCR analysis of the expression of STING in B cells from MRL/lpr mice (n = 9) and wild-type mice (n = 10). (C) B cells were isolated from spleen of MRL/lpr mice (n = 6) and wild-type mice (n = 6). Western blot analysis of the phosphorylation levels of SHP-1/2 and JAK1. (D) BJAB cells were transfected with poly(dA:dT) for 8 h,16 h and 24 h. The expression of STING was analyzed by qPCR. (E) Isolated human CD19+ B cells were stimulated with TLR7 ligand R848 (1 μg/ml), TLR9 ligand CpG2006S (0.5 μM), human anti-IgM (10 μg/ml) and human IFN-α (1,000 U/ml) for 8 h and 16 h. The expression of STING was detected by qPCR. (F) Isolated murine splenic B cells were stimulated with TLR7 ligand R848 (1 μg/ml), TLR9 ligand CpG1826 (0.5 μM), mouse anti-IgM (10 μg/ml) and mouse IFN-α (1,000 U/ml) for 8 h and 16 h. The expression of STING was detected by qPCR. (G) Proposed regulatory pathway activated by dsDNA in B cells. The data shown represent the means of three independent experiments, and the error bars represent the s.e.m. *p < 0.05, **p < 0.01, ***p < 0.001; ns denotes p > 0.05.
Mentions: Since STING plays a negative role in dsDNA-triggered activation of JAK1-STAT1 signaling in B cells, we next detected the expression of STING in B cells from patients with SLE and MRL/lpr mice. PBMCs from patients with SLE and healthy donors were collected and the expression of STING in CD19+ B cells was detected by intracellular FACS analysis. As shown in Fig. 5A, patients with SLE showed a lower expression level of STING in B cells compared with healthy donors. We also detected the expression of STING in splenic B cells from MRL/lpr mice and wild-type mice by qPCR. Consistently, MRL/lpr mice showed a lower expression level of STING (Fig. 5B). These results demonstrate that the expression of STING is down-regulated in B cells from patients with SLE and MRL/lpr mice. Furthermore, we detected the phosphorylation of JAK1, SHP-1 and SHP-2 in B cells isolated from spleen of MRL/lpr mice and wild-type mice. Intriguingly, compared with wild-type mice, MRL/lpr mice showed a significantly higher level of p-JAK1 and lower phosphorylation levels of SHP-1 and SHP-2 in B cells (Fig. 5C).

Bottom Line: In the present study, we found that dsDNA directly triggered the JAK1-STAT1 signaling by inducing phosphorylation of the Lyn kinase.Moreover, this response is not dependent on type I IFN receptors.In addition, compared with normal B cells, the expression of STING was significantly lower and the phosphorylation level of JAK1 was significantly higher in B cells from MRL/lpr lupus-prone mice, highlighting the close association between STING low-expression and JAK1-STAT1 signaling activation in B cells in autoimmune diseases.

View Article: PubMed Central - PubMed

Affiliation: The State Key Laboratory of Pharmaceutical Biotechnology, Division of Immunology, Medical School, Nanjing University, Nanjing 210093, China.

ABSTRACT
Recognition of cytosolic DNA initiates a series of innate immune responses by inducing IFN-I production and subsequent triggering JAK1-STAT1 signaling which plays critical roles in the pathogenesis of infection, inflammation and autoimmune diseases through promoting B cell activation and antibody responses. The stimulator of interferon genes protein (STING) has been demonstrated to be a critical hub of type I IFN induction in cytosolic DNA-sensing pathways. However, it still remains unknown whether cytosolic DNA can directly activate the JAK1-STAT1 signaling or not. And the role of STING is also unclear in this response. In the present study, we found that dsDNA directly triggered the JAK1-STAT1 signaling by inducing phosphorylation of the Lyn kinase. Moreover, this response is not dependent on type I IFN receptors. Interestingly, STING could inhibit dsDNA-triggered activation of JAK1-STAT1 signaling by inducing SHP-1 and SHP-2 phosphorylation. In addition, compared with normal B cells, the expression of STING was significantly lower and the phosphorylation level of JAK1 was significantly higher in B cells from MRL/lpr lupus-prone mice, highlighting the close association between STING low-expression and JAK1-STAT1 signaling activation in B cells in autoimmune diseases. Our data provide a molecular insight into the novel role of STING in dsDNA-mediated inflammatory disorders.

No MeSH data available.


Related in: MedlinePlus