PMC:2222968 / 27614-35146 JSON TXT

Annnotations TAB JSON ListView MergeView

2_test

pmc-enju-pas

bionlp-st-ge-2016-coref

{"project":"bionlp-st-ge-2016-coref","denotations":[{"id":"T14964","span":{"begin":946,"end":959},"obj":"Anaphor"},{"id":"T14965","span":{"begin":867,"end":872},"obj":"Antecedent"},{"id":"T14966","span":{"begin":877,"end":882},"obj":"Antecedent"},{"id":"T14967","span":{"begin":1356,"end":1376},"obj":"Anaphor"},{"id":"T14968","span":{"begin":1391,"end":1395},"obj":"Antecedent"},{"id":"T14969","span":{"begin":1397,"end":1402},"obj":"Antecedent"},{"id":"T14970","span":{"begin":1407,"end":1412},"obj":"Antecedent"},{"id":"T14971","span":{"begin":3556,"end":3576},"obj":"Anaphor"},{"id":"T14972","span":{"begin":3481,"end":3485},"obj":"Antecedent"},{"id":"T14973","span":{"begin":7034,"end":7043},"obj":"Anaphor"},{"id":"T14974","span":{"begin":7052,"end":7056},"obj":"Antecedent"}],"relations":[{"id":"R11393","pred":"boundBy","subj":"T14964","obj":"T14965"},{"id":"R11394","pred":"boundBy","subj":"T14964","obj":"T14966"},{"id":"R11395","pred":"boundBy","subj":"T14967","obj":"T14968"},{"id":"R11396","pred":"boundBy","subj":"T14967","obj":"T14969"},{"id":"R11397","pred":"boundBy","subj":"T14967","obj":"T14970"},{"id":"R11398","pred":"boundBy","subj":"T14971","obj":"T14972"},{"id":"R11399","pred":"boundBy","subj":"T14973","obj":"T14974"}],"namespaces":[{"prefix":"_base","uri":"https://bionlp.dbcls.jp/ontology/ge.owl#"}],"text":"Discussion\nThe current study reveals that FOXP3 induction, an important step in iTreg commitment, is inhibited by GATA3, which is the key regulator for polarization toward Th2 cells. After differentiation, the effector Th2 cells become refractory to conversion into a FOXP3+ phenotype.\nIn accordance with other studies, we found that CD4+CD25– cells were able to up-regulate FOXP3 [12,27]. Already-committed cells such as memory T cells and Th1 cells showed only moderate and transient FOXP3 induction, which is not sufficient to change the phenotype toward a regulatory T cell profile. In contrast, naive T cells could efficiently up-regulate FOXP3 when treated with TGF-β to induce iTreg cells [10,28–34], suggesting that FOXP3 plays an important role in the early differentiation process and may act in a way similar to that known for the Th1/Th2 decision factors T-bet and GATA3. This commitment is characterized by competitive expression of these factors [35,36], which we also observed in differentiating FOXP3+ iTreg cells including a phase of co-expression, which turns into nonoverlapping expression upon completed differentiation. In this competitive process TGF-β appeared to be mandatory for the induction of FOXP3, possibly by keeping the expression of GATA3 and T-bet low [37,38]. In contrast, differentiating naive T cells in the absence of polarization factors (Th0) such as IL-4, IL-12, or TGF-β showed only a transient FOXP3 expression and failed to generate a population of FOXP3-expressing cells, but GATA3 and T-bet were up-regulated (unpublished data). Interestingly, as we and others previously described, FOXP3-promoting factors, such as dexamethasone [39], CTLA-4 [40], and estrogens [41], are also known as inhibitors of GATA3 expression [42–45]. Therefore GATA3 not only induces differentiation into Th2 cells but also inhibits FOXP3 expression and commitment into iTreg cells.\nThe Th2 cytokine IL-4 but not IL-13 (unpublished data) was able to inhibit TGF-β–mediated FOXP3 induction and therefore prevented conversion into the regulatory phenotype. To prove the inhibitory effect of IL-4 on inducible or natural Treg commitment in vivo, we treated mice with IL-4 and anti-IL-4. This has been shown to increase the effect of the cytokine in vivo [19]. Only the IL-4/IL-4 mAb complex resulted in a decrease of the amount of natural or inducible Treg (CD25+ and Foxp3+) cells 7 d after treatment. Our results suggest that IL-4 is only interfering with the differentiation of naive T cells into iTreg cells. But since a distinction of nTreg and iTreg cells is currently not possible, because iTreg cells also transiently express CD25 after activation, we cannot exclude that IL-4 may also inhibit Foxp3 expression in nTreg cells in vivo or that additional effects may contribute to the observed drop in Foxp3 expression. IL-4 has already been shown to negatively regulate the development of naive T cells into Th1 or the IL-17–producing T cells (Th17) [46,47]. Similar effects have been recently described for IL-6, which, combined with TGF-β, inhibits the generation of iTreg cells and induces differentiation into the Th17 cells by an unknown mechanism [48,49]. Thus the polarization into iTreg cells is negatively regulated by the effector cytokines IL-4 and IL-6.\nIL-4 has been previously shown to induce the generation of FOXP3+ Treg cells out of CD4+CD25– [50]. In those experiments, the concentrations of IL-4 used were low, and as we also observed, IL-4 at low concentration slightly enhanced FOXP3 expression. Importantly, these concentrations were not sufficient to induce GATA3 expression. IL-4 may favor proliferation of nTreg cells [47] or directly regulate FOXP3 expression in a STAT-dependent fashion [51].\nSince IL-13 does not effectively reduce FOXP3 and fails to induce GATA3, we hypothesized that the IL-4–dependent inhibition of FOXP3 could be mediated by GATA3. In fact, GATA3-inducing IL-4 concentrations repressed TGF-β–mediated FOXP3 expression, whereas IL-4 as well as TGF-β signaling were intact. This result suggested a competitive mechanism between GATA3 and FOXP3 transcription factors in determining lineage commitment during the early phase of differentiation. Accordingly, we investigated naturally high GATA3-expressing cells and confirmed the absence of FOXP3. Protein transduction of GATA3 into naive T cells inhibited FOXP3 induction in human, differentiating, naive T cells. This inhibitory effect of GATA3 was further confirmed in BALB/c transgenic mice, expressing GATA3 in T cells (DO11.10:CD2-GATA3 transgenic mice). In line with the transient overexpression of GATA3 in human T cells, cells of these mice failed to induce FOXP3 expression upon exposure with antigen in the presence of TGF-β. Strikingly, the DO11.10:CD2-GATA3 mice do have peripheral FOXP3+ cells, which however displayed a 10%–25% lower frequency compared to wild-type DO11.10 mice. Thus GATA3 restrains the development of certain Treg subsets, presumably the inducible, peripheral population and not those of thymic origin. Thymic T cells undergo a different maturation process, which may explain the insensitivity of nTreg to GATA3 overexpression [52]. In contrast to the Th2-differentiating and iTreg-inhibiting function of GATA3 in peripheral T cells, GATA3 acts in the thymus together with other transcription factors such as the Repressor of GATA3 (ROG) in the differentiation process toward CD8 cells [53,54] or participates in complex transcriptional feedback network to regulate sympathoadrenal differentiation [55]. Therefore, the role of GATA3 appears to be tissue specific and cannot be generalized.\nOur study demonstrates that GATA3 repressed FOXP3 expression directly by binding to the FOXP3 promoter region. A palindromic GATA-site is located 303 bp upstream of the TSS in a highly conserved region, which we have previously identified as the FOXP3 promoter [24]. Site-specific mutation of this site increased the activity of the promoter constructs, thus revealing the repressive nature of this GATA element in memory T cells, which naturally express GATA3, whereas no difference was seen in naive T cells, which do not express GATA3. This palindromic GATA element is bound by GATA3 protein as proven with pull-down experiments. Furthermore, it is shown by ChIP that GATA3 binds this element also in intact cells. It is known that GATA3 can induce transcription by chromatin remodeling [56], by directly transactivating promoters [36], or, as shown in the current study, acts as a repressor of gene expression [21,57–59]. Therefore keeping GATA3 expression low might be required to induce efficient FOXP3+ iTreg cell generation.\nThe molecular interactions enabling GATA3 to inhibit FOXP3 are not identified yet, but the GATA-binding site is located adjacent to positive, inducing sites, composed of AP-1-NFATc2 sites [24], and GATA3 may compete with the binding of AP-1/NFAT to the promoter (unpublished observations).\nIn summary, we demonstrated that FOXP3 is negatively regulated by cytokines such as IL-4. GATA3 acts as an inhibitor of FOXP3 expression in early T cell differentiation, as well as in differentiated Th2 cells by directly binding and repressing the FOXP3 promoter. We therefore describe a new mechanism of how Il-4 avoids tolerance induction by repressing FOXP3 expression. These findings will give new perspectives toward understanding molecular mechanisms of iTreg induction and thus pathways of peripheral tolerance induction, particularly in allergy and asthma."}

bionlp-st-ge-2016-spacy-parsed

UBERON-AE

{"project":"UBERON-AE","denotations":[{"id":"T13431","span":{"begin":5307,"end":5313},"obj":"http://purl.obolibrary.org/obo/UBERON_0002370"},{"id":"T13432","span":{"begin":5602,"end":5608},"obj":"http://purl.obolibrary.org/obo/UBERON_0000479"}],"text":"Discussion\nThe current study reveals that FOXP3 induction, an important step in iTreg commitment, is inhibited by GATA3, which is the key regulator for polarization toward Th2 cells. After differentiation, the effector Th2 cells become refractory to conversion into a FOXP3+ phenotype.\nIn accordance with other studies, we found that CD4+CD25– cells were able to up-regulate FOXP3 [12,27]. Already-committed cells such as memory T cells and Th1 cells showed only moderate and transient FOXP3 induction, which is not sufficient to change the phenotype toward a regulatory T cell profile. In contrast, naive T cells could efficiently up-regulate FOXP3 when treated with TGF-β to induce iTreg cells [10,28–34], suggesting that FOXP3 plays an important role in the early differentiation process and may act in a way similar to that known for the Th1/Th2 decision factors T-bet and GATA3. This commitment is characterized by competitive expression of these factors [35,36], which we also observed in differentiating FOXP3+ iTreg cells including a phase of co-expression, which turns into nonoverlapping expression upon completed differentiation. In this competitive process TGF-β appeared to be mandatory for the induction of FOXP3, possibly by keeping the expression of GATA3 and T-bet low [37,38]. In contrast, differentiating naive T cells in the absence of polarization factors (Th0) such as IL-4, IL-12, or TGF-β showed only a transient FOXP3 expression and failed to generate a population of FOXP3-expressing cells, but GATA3 and T-bet were up-regulated (unpublished data). Interestingly, as we and others previously described, FOXP3-promoting factors, such as dexamethasone [39], CTLA-4 [40], and estrogens [41], are also known as inhibitors of GATA3 expression [42–45]. Therefore GATA3 not only induces differentiation into Th2 cells but also inhibits FOXP3 expression and commitment into iTreg cells.\nThe Th2 cytokine IL-4 but not IL-13 (unpublished data) was able to inhibit TGF-β–mediated FOXP3 induction and therefore prevented conversion into the regulatory phenotype. To prove the inhibitory effect of IL-4 on inducible or natural Treg commitment in vivo, we treated mice with IL-4 and anti-IL-4. This has been shown to increase the effect of the cytokine in vivo [19]. Only the IL-4/IL-4 mAb complex resulted in a decrease of the amount of natural or inducible Treg (CD25+ and Foxp3+) cells 7 d after treatment. Our results suggest that IL-4 is only interfering with the differentiation of naive T cells into iTreg cells. But since a distinction of nTreg and iTreg cells is currently not possible, because iTreg cells also transiently express CD25 after activation, we cannot exclude that IL-4 may also inhibit Foxp3 expression in nTreg cells in vivo or that additional effects may contribute to the observed drop in Foxp3 expression. IL-4 has already been shown to negatively regulate the development of naive T cells into Th1 or the IL-17–producing T cells (Th17) [46,47]. Similar effects have been recently described for IL-6, which, combined with TGF-β, inhibits the generation of iTreg cells and induces differentiation into the Th17 cells by an unknown mechanism [48,49]. Thus the polarization into iTreg cells is negatively regulated by the effector cytokines IL-4 and IL-6.\nIL-4 has been previously shown to induce the generation of FOXP3+ Treg cells out of CD4+CD25– [50]. In those experiments, the concentrations of IL-4 used were low, and as we also observed, IL-4 at low concentration slightly enhanced FOXP3 expression. Importantly, these concentrations were not sufficient to induce GATA3 expression. IL-4 may favor proliferation of nTreg cells [47] or directly regulate FOXP3 expression in a STAT-dependent fashion [51].\nSince IL-13 does not effectively reduce FOXP3 and fails to induce GATA3, we hypothesized that the IL-4–dependent inhibition of FOXP3 could be mediated by GATA3. In fact, GATA3-inducing IL-4 concentrations repressed TGF-β–mediated FOXP3 expression, whereas IL-4 as well as TGF-β signaling were intact. This result suggested a competitive mechanism between GATA3 and FOXP3 transcription factors in determining lineage commitment during the early phase of differentiation. Accordingly, we investigated naturally high GATA3-expressing cells and confirmed the absence of FOXP3. Protein transduction of GATA3 into naive T cells inhibited FOXP3 induction in human, differentiating, naive T cells. This inhibitory effect of GATA3 was further confirmed in BALB/c transgenic mice, expressing GATA3 in T cells (DO11.10:CD2-GATA3 transgenic mice). In line with the transient overexpression of GATA3 in human T cells, cells of these mice failed to induce FOXP3 expression upon exposure with antigen in the presence of TGF-β. Strikingly, the DO11.10:CD2-GATA3 mice do have peripheral FOXP3+ cells, which however displayed a 10%–25% lower frequency compared to wild-type DO11.10 mice. Thus GATA3 restrains the development of certain Treg subsets, presumably the inducible, peripheral population and not those of thymic origin. Thymic T cells undergo a different maturation process, which may explain the insensitivity of nTreg to GATA3 overexpression [52]. In contrast to the Th2-differentiating and iTreg-inhibiting function of GATA3 in peripheral T cells, GATA3 acts in the thymus together with other transcription factors such as the Repressor of GATA3 (ROG) in the differentiation process toward CD8 cells [53,54] or participates in complex transcriptional feedback network to regulate sympathoadrenal differentiation [55]. Therefore, the role of GATA3 appears to be tissue specific and cannot be generalized.\nOur study demonstrates that GATA3 repressed FOXP3 expression directly by binding to the FOXP3 promoter region. A palindromic GATA-site is located 303 bp upstream of the TSS in a highly conserved region, which we have previously identified as the FOXP3 promoter [24]. Site-specific mutation of this site increased the activity of the promoter constructs, thus revealing the repressive nature of this GATA element in memory T cells, which naturally express GATA3, whereas no difference was seen in naive T cells, which do not express GATA3. This palindromic GATA element is bound by GATA3 protein as proven with pull-down experiments. Furthermore, it is shown by ChIP that GATA3 binds this element also in intact cells. It is known that GATA3 can induce transcription by chromatin remodeling [56], by directly transactivating promoters [36], or, as shown in the current study, acts as a repressor of gene expression [21,57–59]. Therefore keeping GATA3 expression low might be required to induce efficient FOXP3+ iTreg cell generation.\nThe molecular interactions enabling GATA3 to inhibit FOXP3 are not identified yet, but the GATA-binding site is located adjacent to positive, inducing sites, composed of AP-1-NFATc2 sites [24], and GATA3 may compete with the binding of AP-1/NFAT to the promoter (unpublished observations).\nIn summary, we demonstrated that FOXP3 is negatively regulated by cytokines such as IL-4. GATA3 acts as an inhibitor of FOXP3 expression in early T cell differentiation, as well as in differentiated Th2 cells by directly binding and repressing the FOXP3 promoter. We therefore describe a new mechanism of how Il-4 avoids tolerance induction by repressing FOXP3 expression. These findings will give new perspectives toward understanding molecular mechanisms of iTreg induction and thus pathways of peripheral tolerance induction, particularly in allergy and asthma."}

GO-BP

GO-MF

GO-CC

sentences

ICD10

{"project":"ICD10","denotations":[{"id":"T16682","span":{"begin":7513,"end":7520},"obj":"http://purl.bioontology.org/ontology/ICD10/T78.4"},{"id":"T16683","span":{"begin":7525,"end":7531},"obj":"http://purl.bioontology.org/ontology/ICD10/J45.9"},{"id":"T16684","span":{"begin":7525,"end":7531},"obj":"http://purl.bioontology.org/ontology/ICD10/J45"}],"text":"Discussion\nThe current study reveals that FOXP3 induction, an important step in iTreg commitment, is inhibited by GATA3, which is the key regulator for polarization toward Th2 cells. After differentiation, the effector Th2 cells become refractory to conversion into a FOXP3+ phenotype.\nIn accordance with other studies, we found that CD4+CD25– cells were able to up-regulate FOXP3 [12,27]. Already-committed cells such as memory T cells and Th1 cells showed only moderate and transient FOXP3 induction, which is not sufficient to change the phenotype toward a regulatory T cell profile. In contrast, naive T cells could efficiently up-regulate FOXP3 when treated with TGF-β to induce iTreg cells [10,28–34], suggesting that FOXP3 plays an important role in the early differentiation process and may act in a way similar to that known for the Th1/Th2 decision factors T-bet and GATA3. This commitment is characterized by competitive expression of these factors [35,36], which we also observed in differentiating FOXP3+ iTreg cells including a phase of co-expression, which turns into nonoverlapping expression upon completed differentiation. In this competitive process TGF-β appeared to be mandatory for the induction of FOXP3, possibly by keeping the expression of GATA3 and T-bet low [37,38]. In contrast, differentiating naive T cells in the absence of polarization factors (Th0) such as IL-4, IL-12, or TGF-β showed only a transient FOXP3 expression and failed to generate a population of FOXP3-expressing cells, but GATA3 and T-bet were up-regulated (unpublished data). Interestingly, as we and others previously described, FOXP3-promoting factors, such as dexamethasone [39], CTLA-4 [40], and estrogens [41], are also known as inhibitors of GATA3 expression [42–45]. Therefore GATA3 not only induces differentiation into Th2 cells but also inhibits FOXP3 expression and commitment into iTreg cells.\nThe Th2 cytokine IL-4 but not IL-13 (unpublished data) was able to inhibit TGF-β–mediated FOXP3 induction and therefore prevented conversion into the regulatory phenotype. To prove the inhibitory effect of IL-4 on inducible or natural Treg commitment in vivo, we treated mice with IL-4 and anti-IL-4. This has been shown to increase the effect of the cytokine in vivo [19]. Only the IL-4/IL-4 mAb complex resulted in a decrease of the amount of natural or inducible Treg (CD25+ and Foxp3+) cells 7 d after treatment. Our results suggest that IL-4 is only interfering with the differentiation of naive T cells into iTreg cells. But since a distinction of nTreg and iTreg cells is currently not possible, because iTreg cells also transiently express CD25 after activation, we cannot exclude that IL-4 may also inhibit Foxp3 expression in nTreg cells in vivo or that additional effects may contribute to the observed drop in Foxp3 expression. IL-4 has already been shown to negatively regulate the development of naive T cells into Th1 or the IL-17–producing T cells (Th17) [46,47]. Similar effects have been recently described for IL-6, which, combined with TGF-β, inhibits the generation of iTreg cells and induces differentiation into the Th17 cells by an unknown mechanism [48,49]. Thus the polarization into iTreg cells is negatively regulated by the effector cytokines IL-4 and IL-6.\nIL-4 has been previously shown to induce the generation of FOXP3+ Treg cells out of CD4+CD25– [50]. In those experiments, the concentrations of IL-4 used were low, and as we also observed, IL-4 at low concentration slightly enhanced FOXP3 expression. Importantly, these concentrations were not sufficient to induce GATA3 expression. IL-4 may favor proliferation of nTreg cells [47] or directly regulate FOXP3 expression in a STAT-dependent fashion [51].\nSince IL-13 does not effectively reduce FOXP3 and fails to induce GATA3, we hypothesized that the IL-4–dependent inhibition of FOXP3 could be mediated by GATA3. In fact, GATA3-inducing IL-4 concentrations repressed TGF-β–mediated FOXP3 expression, whereas IL-4 as well as TGF-β signaling were intact. This result suggested a competitive mechanism between GATA3 and FOXP3 transcription factors in determining lineage commitment during the early phase of differentiation. Accordingly, we investigated naturally high GATA3-expressing cells and confirmed the absence of FOXP3. Protein transduction of GATA3 into naive T cells inhibited FOXP3 induction in human, differentiating, naive T cells. This inhibitory effect of GATA3 was further confirmed in BALB/c transgenic mice, expressing GATA3 in T cells (DO11.10:CD2-GATA3 transgenic mice). In line with the transient overexpression of GATA3 in human T cells, cells of these mice failed to induce FOXP3 expression upon exposure with antigen in the presence of TGF-β. Strikingly, the DO11.10:CD2-GATA3 mice do have peripheral FOXP3+ cells, which however displayed a 10%–25% lower frequency compared to wild-type DO11.10 mice. Thus GATA3 restrains the development of certain Treg subsets, presumably the inducible, peripheral population and not those of thymic origin. Thymic T cells undergo a different maturation process, which may explain the insensitivity of nTreg to GATA3 overexpression [52]. In contrast to the Th2-differentiating and iTreg-inhibiting function of GATA3 in peripheral T cells, GATA3 acts in the thymus together with other transcription factors such as the Repressor of GATA3 (ROG) in the differentiation process toward CD8 cells [53,54] or participates in complex transcriptional feedback network to regulate sympathoadrenal differentiation [55]. Therefore, the role of GATA3 appears to be tissue specific and cannot be generalized.\nOur study demonstrates that GATA3 repressed FOXP3 expression directly by binding to the FOXP3 promoter region. A palindromic GATA-site is located 303 bp upstream of the TSS in a highly conserved region, which we have previously identified as the FOXP3 promoter [24]. Site-specific mutation of this site increased the activity of the promoter constructs, thus revealing the repressive nature of this GATA element in memory T cells, which naturally express GATA3, whereas no difference was seen in naive T cells, which do not express GATA3. This palindromic GATA element is bound by GATA3 protein as proven with pull-down experiments. Furthermore, it is shown by ChIP that GATA3 binds this element also in intact cells. It is known that GATA3 can induce transcription by chromatin remodeling [56], by directly transactivating promoters [36], or, as shown in the current study, acts as a repressor of gene expression [21,57–59]. Therefore keeping GATA3 expression low might be required to induce efficient FOXP3+ iTreg cell generation.\nThe molecular interactions enabling GATA3 to inhibit FOXP3 are not identified yet, but the GATA-binding site is located adjacent to positive, inducing sites, composed of AP-1-NFATc2 sites [24], and GATA3 may compete with the binding of AP-1/NFAT to the promoter (unpublished observations).\nIn summary, we demonstrated that FOXP3 is negatively regulated by cytokines such as IL-4. GATA3 acts as an inhibitor of FOXP3 expression in early T cell differentiation, as well as in differentiated Th2 cells by directly binding and repressing the FOXP3 promoter. We therefore describe a new mechanism of how Il-4 avoids tolerance induction by repressing FOXP3 expression. These findings will give new perspectives toward understanding molecular mechanisms of iTreg induction and thus pathways of peripheral tolerance induction, particularly in allergy and asthma."}

events-check-again

bionlp-st-ge-2016-reference

bionlp-st-ge-2016-uniprot

test2

PMC:2222968 / 27614-35146 JSONTXT

Annnotations TAB JSON ListView MergeView

PMC:2222968 / 27614-35146 JSON TXT