PMC:1064873 / 23422-34571 JSON TXT

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LappsTest

2_test

pmc-enju-pas

bionlp-st-ge-2016-coref

bionlp-st-ge-2016-test-proteins

bionlp-st-ge-2016-uniprot

UBERON-AE

{"project":"UBERON-AE","denotations":[{"id":"T22796","span":{"begin":10856,"end":10861},"obj":"http://purl.obolibrary.org/obo/UBERON_0001977"},{"id":"T22795","span":{"begin":9890,"end":9895},"obj":"http://purl.obolibrary.org/obo/UBERON_0001977"},{"id":"T22794","span":{"begin":5651,"end":5656},"obj":"http://purl.obolibrary.org/obo/UBERON_0001977"},{"id":"T22793","span":{"begin":5313,"end":5318},"obj":"http://purl.obolibrary.org/obo/UBERON_0001977"},{"id":"T22792","span":{"begin":6224,"end":6229},"obj":"http://purl.obolibrary.org/obo/UBERON_0000178"},{"id":"T22791","span":{"begin":5200,"end":5205},"obj":"http://purl.obolibrary.org/obo/UBERON_0000178"},{"id":"T22790","span":{"begin":7304,"end":7318},"obj":"http://purl.obolibrary.org/obo/UBERON_0001090"},{"id":"T22789","span":{"begin":7195,"end":7209},"obj":"http://purl.obolibrary.org/obo/UBERON_0001090"},{"id":"T22788","span":{"begin":4045,"end":4060},"obj":"http://purl.obolibrary.org/obo/UBERON_0001090"}],"text":"Discussion\nCD4+ T cells orchestrate the Th1-type cell-mediated immune response in RA [22]. Activated CD4+ T cells stimulate macrophages, synovial fibroblasts, B cells, and osteoclasts through the expression of cell surface molecules and Th1 cytokines, thereby contributing to both the chronic inflammation and the joint destruction. CD4+ T cells require two signals to be activated; antigen receptor occupancy and CD28-mediated costimulation. In the ST lesion, the CD28 ligands, both CD80 and CD86, together with MHC class II antigens, are substantially expressed by antigen-presenting cells such as macrophages and dendritic cells [18-20]. The significance of CD28 engagement in the T-cell-mediated disease process has recently been proven by the clinical efficacy of its blocker cytotoxic T-cell-associated antigen 4 (CD152)-IgG in RA patients [23].\nIL-10 plays a predominant role in limiting immune and inflammatory responses by regulating the function of both macrophages and Th1 cells [1]. IL-10 inhibits the tyrosine phosphorylation of the CD28 molecule and the subsequent phosphatidylinositol 3-kinase binding in T cells, and thereby directly acts on T cells [24]. In the present study, we found that PB CD4+ T cells from patients with active RA, in the presence of IL-10, are able to produce higher levels of IFN-γ after CD3 and CD28 costimulation than normal CD4+ T cells. Despite high-level IL-10R1 expression and constitutive STAT3 activation, IL-10-induced tyrosine phosphorylation of STAT3 is suppressed in RA CD4+ T cells, in contrast to normal CD4+ T cells, where STAT3 phosphorylation is dose-dependently inducible by IL-10. Serum IL-6 from RA patients induces STAT3 but not STAT1 phosphorylation in normal CD4+ T cells, and exogenous IL-6 induces the resistance to IL-10 inhibition of IFN-γ production. RA CD4+ T cells contain higher levels of SOCS1 but contain lower levels of SOCS3 transcripts in comparison with normal CD4+ T cells. These findings indicate that CD4+ T cells become resistant to the inhibitory effect of IL-10 before migration into the inflamed ST, and suggest that this resistance may be attributable to impaired IL-10-dependent STAT3 activation, in association with sustained STAT3 phosphorylation and SOCS1 induction.\nIL-10-mediated inhibition of CD4+ T-cell cytokine production is principally dependent on its inhibition of macrophage antigen-presenting cell function [1]. However, this indirect inhibitory effect is thought to be restricted at the site of T-cell activation in RA, because macrophages in the ST express high levels of cytokines, CD80 and CD86 molecules, and MHC class II antigens [10,18-20]. More recently, IL-10 has been shown to induce the antigen-specific T-cell unresponsiveness by inhibiting CD28 tyrosine phosphorylation [33]. This direct effect also may be limited in active RA patients, because their PB CD4+ T cells showed a defective IL-10 inhibition of CD28-costimulated production of both IFN-γ and IL-2.\nNumerous cytokines, both proinflammatory and anti-inflammatory, have been detected in the ST of RA, and the balance between these opposing cytokine activities regulates disease severity [10]. Endogenous IL-10, produced mainly by macrophages and T cells, inhibits proinflammatory cytokine production by ST cells [12]. However, this regulatory activity seems to be restricted during chronic inflammation. The activation of both the extracellular stimulus-regulated kinase and p38 kinase pathways, induced by TNF-α and IL-1, inhibits the Jak1–STAT3 signaling pathway shared by IL-10 and IL-6 in adhered macrophages [13]. More importantly, IL-10-mediated STAT3 activation is mostly undetectable in RA synovial macrophages. This impaired IL-10 signaling is probably induced by chronic exposure to immune complexes in vivo, because both cell surface IL-10R1 expression and IL-10-induced Jak1 activation are suppressed in IFN-γ-primed macrophages by a protein kinase C-dependent pathway following ligation of the IgG Fc gamma receptor [14]. Furthermore, dendritic cells from RA synovial fluids are resistant to the immunoregulatory effect of IL-10 due to decreased transport of intracellular IL-10R1 in the presence of proinflammatory cytokine stimuli such as TNF-α, IL-1, and granulocyte–macrophage colony-stimulating factor [15]. We have demonstrated that the resistance of RA CD4+ T cells to IL-10 may be associated with defective IL-10-dependent STAT3 activation, but not with IL-10R1 expression. Inhibitory effects of IL-10 on these inflammatory cell types are therefore differentially modulated at the signal transduction level under the inflammatory environment in RA.\nIn association with impaired IL-10-mediated STAT3 activation, STAT3 was found to be tyrosine phosphorylated persistently (up to 6 hours) in freshly isolated PB and ST CD4+ T cells from RA patients. STAT3 is activated by a variety of cytokines, notably the IL-6 family of cytokines (e.g. IL-6, IL-11, leukemia inhibitory factor, and oncostatin M) and growth factors, in addition to IL-10 [4]. Of these cytokines, IL-6 plays a predominant role in eliciting a systemic reaction such as the acute phase response in active RA, due mainly to its abundance in the blood circulation [27]. Consistent with this notion, IL-6 was the major STAT3-activating factor contained in the serum of active RA patients, and the responsiveness to IL-10 was suppressed in normal CD4+ T cells after 36 hours of incubation with IL-6. These results suggest that both the sustained STAT3 activation and the resistance to IL-10 inhibition found in RA CD4+ T cells may be induced after chronic exposure in vivo to high concentrations of serum IL-6. However, it is also possible that STAT3 activity could be constitutively induced in CD4+ T cells by their own IL-10 secretion, leading to the loss of sensitivity to exogenous IL-10, because RA CD4+ T cells in the ST are capable of producing significant levels of IL-10 [34].\nCD4+ T cells isolated from the ST of RA also showed a defect in the IL-10-induced STAT3 signaling pathway. It is most probable that the resistance of CD4+ T cells to IL-10 can be even augmented after migration into the inflamed ST, because IL-6 is highly concentrated compared with the blood level [27]. In addition, the involvement of other essential proinflammatory cytokines in this process was suggested by our preliminary experiments demonstrating that IL-10-mediated IFN-γ inhibition in CD4+ T cells was reduced by pretreatment with IL-1β and TNF-α, although less effectively than by IL-6 (data not shown). Furthermore, IFN-γ and IL-10 produced by CD4+ T cells themselves could be responsible for impaired IL-10 signaling in the ST, because T-cell infiltrates produce both cytokines [34,35]. In an autocrine fashion, IL-10 may persistently stimulate STAT3 activation and IFN-γ can induce SOCS1 protein as a crosstalk inhibitor of IL-10 signaling [32]. The T-cell-inhibitory effect of IL-10 may therefore be modulated complicatedly upon exposure to an inflammatory environment in RA joints, where many cytokines are present substantially [10].\nSTAT3 activation has been implicated in the pathogenesis of RA. Active STAT3 is constitutively expressed in synovial fluid mononuclear cells from RA patients [36]. IL-6 is the major STAT3-activating factor present in synovial fluid, which has a crucial role in the activation of monocyte functions such as gene expression of the Fc gamma receptor type I and type III and of HLA-DR [31]. More recently, high levels of activated STAT3, thought to be induced mainly by IL-6, have been detected in the ST, and STAT3 activation has been shown to be involved in synovial fibroblast proliferation and IL-6 production [37]. In this regard, STAT3 is critical in the survival and expansion of growth factor-dependent synovial fibroblasts [38]. Furthermore, the significance of persistent STAT3 signaling in Th1-cell-dominated autoimmune arthritis has been suggested by studies of the gp130F759/F759 mice, in which the Src homology phosphatase-2 binding site of gp130 (the transmembrane glycoprotein β subunit of the IL-6 family cytokine receptor), tyrosine 759, was mutated to phenylalanine [39]. In the gp130F759/F759 mice, T cells, particularly the CD4+ T-cell subset, are chronically activated and resistant to activation-induced cell death through gp130-mediated STAT3 activation.\nThe longevity of cytokine signals transduced by the JAK–STAT pathway is regulated by the SOCS family proteins [7]. We found that CD4+ T cells from patients with active RA expressed higher levels of SOCS1, but lower levels of SOCS3, compared with normal CD4+ T cells. SOCS1 prevents activation of JAK by directly binding to JAK, and SOCS3 inhibits the action of JAK by binding to the Src homology phosphatase-2-binding domain of receptors such as gp130 [40]. SOCS1 and SOCS3 are induced by various cytokines, including IL-6 and IL-10, as mediators of negative feedback and crosstalk inhibition [7]. Recent studies with mice lacking SOCS3 or SOCS1 revealed that SOCS3 is a negative regulator of IL-6 signaling but not of IL-10 signaling. Studies of conditional SOCS3-deficient mice have shown that SOCS3 deficiency, but not SOCS1 deficiency, results in sustained activation of STAT3 in response to IL-6 [8,41]. The analysis of SOCS3-deficient macrophages has indicated that SOCS3 is a crucial inhibitor of the IL-6-induced transcriptional response [42]. However, SOCS3 is dispensable for both the negative feedback inhibition and the immunoregulatory action of IL-10 in macrophages [41]. On the contrary, SOCS1 was found to directly inhibit IL-10-mediated signaling [43]. Increased SOCS1 expression in RA CD4+ T cells may therefore be associated with both the impaired responsiveness to IL-10 and to IL-10-mediated STAT3 activation, and defective SOCS3 expression may be responsible for persistent STAT3 activation in response to serum IL-6.\nThere is a possibility that SOCS1 induction may be associated with the ability of CD4+ T cells to produce IFN-γ, because CD4+ T cells from active RA could produce high levels of IFN-γ in the presence of IL-10, and because IFN-γ has been known as a potent inducer of SOCS1 [32]. It is of interest in this regard to indicate that polarized Th1 and Th2 cells express high levels of SOCS1 and SOCS3 mRNA, respectively [44]. IL-12-induced STAT4 activation is inhibited by SOCS3 induction in Th2 cells, whereas IL-4-induced STAT6 signaling is diminished by SOCS1 induction in Th1 cells. SOCS1 and SOCS3 may thus have important roles as Th1-specific and Th2-specific, mutually exclusive, cross-talk repressors of the IL-4–STAT6 and the IL-12–STAT4 signaling pathways, respectively. Consistent with this notion, PB T cells from patients with allergic diseases significantly express high levels of SOCS3 transcripts, and the SOCS3 expression correlates well with serum IgE levels and disease pathology [45]. Higher SOCS1 expression with lower SOCS3 expression in PB CD4+ T cells from RA patients, compared with healthy controls, is therefore probably consistent with their systemic bias towards a Th1 phenotype, as has previously been demonstrated [46-49]."}

GO-BP

GO-CC

GO-MF

sentences

ICD10

{"project":"ICD10","denotations":[{"id":"T23695","span":{"begin":7914,"end":7923},"obj":"http://purl.bioontology.org/ontology/ICD10/M13.9"}],"text":"Discussion\nCD4+ T cells orchestrate the Th1-type cell-mediated immune response in RA [22]. Activated CD4+ T cells stimulate macrophages, synovial fibroblasts, B cells, and osteoclasts through the expression of cell surface molecules and Th1 cytokines, thereby contributing to both the chronic inflammation and the joint destruction. CD4+ T cells require two signals to be activated; antigen receptor occupancy and CD28-mediated costimulation. In the ST lesion, the CD28 ligands, both CD80 and CD86, together with MHC class II antigens, are substantially expressed by antigen-presenting cells such as macrophages and dendritic cells [18-20]. The significance of CD28 engagement in the T-cell-mediated disease process has recently been proven by the clinical efficacy of its blocker cytotoxic T-cell-associated antigen 4 (CD152)-IgG in RA patients [23].\nIL-10 plays a predominant role in limiting immune and inflammatory responses by regulating the function of both macrophages and Th1 cells [1]. IL-10 inhibits the tyrosine phosphorylation of the CD28 molecule and the subsequent phosphatidylinositol 3-kinase binding in T cells, and thereby directly acts on T cells [24]. In the present study, we found that PB CD4+ T cells from patients with active RA, in the presence of IL-10, are able to produce higher levels of IFN-γ after CD3 and CD28 costimulation than normal CD4+ T cells. Despite high-level IL-10R1 expression and constitutive STAT3 activation, IL-10-induced tyrosine phosphorylation of STAT3 is suppressed in RA CD4+ T cells, in contrast to normal CD4+ T cells, where STAT3 phosphorylation is dose-dependently inducible by IL-10. Serum IL-6 from RA patients induces STAT3 but not STAT1 phosphorylation in normal CD4+ T cells, and exogenous IL-6 induces the resistance to IL-10 inhibition of IFN-γ production. RA CD4+ T cells contain higher levels of SOCS1 but contain lower levels of SOCS3 transcripts in comparison with normal CD4+ T cells. These findings indicate that CD4+ T cells become resistant to the inhibitory effect of IL-10 before migration into the inflamed ST, and suggest that this resistance may be attributable to impaired IL-10-dependent STAT3 activation, in association with sustained STAT3 phosphorylation and SOCS1 induction.\nIL-10-mediated inhibition of CD4+ T-cell cytokine production is principally dependent on its inhibition of macrophage antigen-presenting cell function [1]. However, this indirect inhibitory effect is thought to be restricted at the site of T-cell activation in RA, because macrophages in the ST express high levels of cytokines, CD80 and CD86 molecules, and MHC class II antigens [10,18-20]. More recently, IL-10 has been shown to induce the antigen-specific T-cell unresponsiveness by inhibiting CD28 tyrosine phosphorylation [33]. This direct effect also may be limited in active RA patients, because their PB CD4+ T cells showed a defective IL-10 inhibition of CD28-costimulated production of both IFN-γ and IL-2.\nNumerous cytokines, both proinflammatory and anti-inflammatory, have been detected in the ST of RA, and the balance between these opposing cytokine activities regulates disease severity [10]. Endogenous IL-10, produced mainly by macrophages and T cells, inhibits proinflammatory cytokine production by ST cells [12]. However, this regulatory activity seems to be restricted during chronic inflammation. The activation of both the extracellular stimulus-regulated kinase and p38 kinase pathways, induced by TNF-α and IL-1, inhibits the Jak1–STAT3 signaling pathway shared by IL-10 and IL-6 in adhered macrophages [13]. More importantly, IL-10-mediated STAT3 activation is mostly undetectable in RA synovial macrophages. This impaired IL-10 signaling is probably induced by chronic exposure to immune complexes in vivo, because both cell surface IL-10R1 expression and IL-10-induced Jak1 activation are suppressed in IFN-γ-primed macrophages by a protein kinase C-dependent pathway following ligation of the IgG Fc gamma receptor [14]. Furthermore, dendritic cells from RA synovial fluids are resistant to the immunoregulatory effect of IL-10 due to decreased transport of intracellular IL-10R1 in the presence of proinflammatory cytokine stimuli such as TNF-α, IL-1, and granulocyte–macrophage colony-stimulating factor [15]. We have demonstrated that the resistance of RA CD4+ T cells to IL-10 may be associated with defective IL-10-dependent STAT3 activation, but not with IL-10R1 expression. Inhibitory effects of IL-10 on these inflammatory cell types are therefore differentially modulated at the signal transduction level under the inflammatory environment in RA.\nIn association with impaired IL-10-mediated STAT3 activation, STAT3 was found to be tyrosine phosphorylated persistently (up to 6 hours) in freshly isolated PB and ST CD4+ T cells from RA patients. STAT3 is activated by a variety of cytokines, notably the IL-6 family of cytokines (e.g. IL-6, IL-11, leukemia inhibitory factor, and oncostatin M) and growth factors, in addition to IL-10 [4]. Of these cytokines, IL-6 plays a predominant role in eliciting a systemic reaction such as the acute phase response in active RA, due mainly to its abundance in the blood circulation [27]. Consistent with this notion, IL-6 was the major STAT3-activating factor contained in the serum of active RA patients, and the responsiveness to IL-10 was suppressed in normal CD4+ T cells after 36 hours of incubation with IL-6. These results suggest that both the sustained STAT3 activation and the resistance to IL-10 inhibition found in RA CD4+ T cells may be induced after chronic exposure in vivo to high concentrations of serum IL-6. However, it is also possible that STAT3 activity could be constitutively induced in CD4+ T cells by their own IL-10 secretion, leading to the loss of sensitivity to exogenous IL-10, because RA CD4+ T cells in the ST are capable of producing significant levels of IL-10 [34].\nCD4+ T cells isolated from the ST of RA also showed a defect in the IL-10-induced STAT3 signaling pathway. It is most probable that the resistance of CD4+ T cells to IL-10 can be even augmented after migration into the inflamed ST, because IL-6 is highly concentrated compared with the blood level [27]. In addition, the involvement of other essential proinflammatory cytokines in this process was suggested by our preliminary experiments demonstrating that IL-10-mediated IFN-γ inhibition in CD4+ T cells was reduced by pretreatment with IL-1β and TNF-α, although less effectively than by IL-6 (data not shown). Furthermore, IFN-γ and IL-10 produced by CD4+ T cells themselves could be responsible for impaired IL-10 signaling in the ST, because T-cell infiltrates produce both cytokines [34,35]. In an autocrine fashion, IL-10 may persistently stimulate STAT3 activation and IFN-γ can induce SOCS1 protein as a crosstalk inhibitor of IL-10 signaling [32]. The T-cell-inhibitory effect of IL-10 may therefore be modulated complicatedly upon exposure to an inflammatory environment in RA joints, where many cytokines are present substantially [10].\nSTAT3 activation has been implicated in the pathogenesis of RA. Active STAT3 is constitutively expressed in synovial fluid mononuclear cells from RA patients [36]. IL-6 is the major STAT3-activating factor present in synovial fluid, which has a crucial role in the activation of monocyte functions such as gene expression of the Fc gamma receptor type I and type III and of HLA-DR [31]. More recently, high levels of activated STAT3, thought to be induced mainly by IL-6, have been detected in the ST, and STAT3 activation has been shown to be involved in synovial fibroblast proliferation and IL-6 production [37]. In this regard, STAT3 is critical in the survival and expansion of growth factor-dependent synovial fibroblasts [38]. Furthermore, the significance of persistent STAT3 signaling in Th1-cell-dominated autoimmune arthritis has been suggested by studies of the gp130F759/F759 mice, in which the Src homology phosphatase-2 binding site of gp130 (the transmembrane glycoprotein β subunit of the IL-6 family cytokine receptor), tyrosine 759, was mutated to phenylalanine [39]. In the gp130F759/F759 mice, T cells, particularly the CD4+ T-cell subset, are chronically activated and resistant to activation-induced cell death through gp130-mediated STAT3 activation.\nThe longevity of cytokine signals transduced by the JAK–STAT pathway is regulated by the SOCS family proteins [7]. We found that CD4+ T cells from patients with active RA expressed higher levels of SOCS1, but lower levels of SOCS3, compared with normal CD4+ T cells. SOCS1 prevents activation of JAK by directly binding to JAK, and SOCS3 inhibits the action of JAK by binding to the Src homology phosphatase-2-binding domain of receptors such as gp130 [40]. SOCS1 and SOCS3 are induced by various cytokines, including IL-6 and IL-10, as mediators of negative feedback and crosstalk inhibition [7]. Recent studies with mice lacking SOCS3 or SOCS1 revealed that SOCS3 is a negative regulator of IL-6 signaling but not of IL-10 signaling. Studies of conditional SOCS3-deficient mice have shown that SOCS3 deficiency, but not SOCS1 deficiency, results in sustained activation of STAT3 in response to IL-6 [8,41]. The analysis of SOCS3-deficient macrophages has indicated that SOCS3 is a crucial inhibitor of the IL-6-induced transcriptional response [42]. However, SOCS3 is dispensable for both the negative feedback inhibition and the immunoregulatory action of IL-10 in macrophages [41]. On the contrary, SOCS1 was found to directly inhibit IL-10-mediated signaling [43]. Increased SOCS1 expression in RA CD4+ T cells may therefore be associated with both the impaired responsiveness to IL-10 and to IL-10-mediated STAT3 activation, and defective SOCS3 expression may be responsible for persistent STAT3 activation in response to serum IL-6.\nThere is a possibility that SOCS1 induction may be associated with the ability of CD4+ T cells to produce IFN-γ, because CD4+ T cells from active RA could produce high levels of IFN-γ in the presence of IL-10, and because IFN-γ has been known as a potent inducer of SOCS1 [32]. It is of interest in this regard to indicate that polarized Th1 and Th2 cells express high levels of SOCS1 and SOCS3 mRNA, respectively [44]. IL-12-induced STAT4 activation is inhibited by SOCS3 induction in Th2 cells, whereas IL-4-induced STAT6 signaling is diminished by SOCS1 induction in Th1 cells. SOCS1 and SOCS3 may thus have important roles as Th1-specific and Th2-specific, mutually exclusive, cross-talk repressors of the IL-4–STAT6 and the IL-12–STAT4 signaling pathways, respectively. Consistent with this notion, PB T cells from patients with allergic diseases significantly express high levels of SOCS3 transcripts, and the SOCS3 expression correlates well with serum IgE levels and disease pathology [45]. Higher SOCS1 expression with lower SOCS3 expression in PB CD4+ T cells from RA patients, compared with healthy controls, is therefore probably consistent with their systemic bias towards a Th1 phenotype, as has previously been demonstrated [46-49]."}

simple1

BioNLP16_DUT

BioNLP16_Messiy

DLUT931

bionlp-st-ge-2016-test-ihmc

bionlp-st-ge-2016-spacy-parsed

bionlp-st-ge-2016-test-tees

test3

testone

PMC:1064873 / 23422-34571 JSONTXT

Annnotations TAB JSON ListView MergeView

PMC:1064873 / 23422-34571 JSON TXT