DNA methylation controls Foxp3 gene expression Polansky, Julia K; Kretschmer, Karsten; Freyer, Jennifer ...
European journal of immunology,
June 2008, Volume:
38, Issue:
6
Journal Article
Peer reviewed
Open access
Compelling evidence suggests that Foxp3-expressing CD25⁺CD4⁺ regulatory T cells (Treg) are generated within the thymus as a separate lineage. However, Foxp3⁺CD4⁺ Treg can also be generated de novo in ...a TGF-β-dependent process from naive T cells by TCR triggering. Recently, we have shown that naturally occurring, but not in vitro TGF-β-induced Foxp3⁺ Treg display stable Foxp3 expression that was associated with selective demethylation of an evolutionarily conserved element within the Foxp3 locus named TSDR (Treg-specific demethylated region). Here, we report that inhibition of DNA methylation by azacytidine, even in absence of exogenous TGF-β, not only promoted de novo induction of Foxp3 expression during priming, but also conferred stability of Foxp3 expression upon restimulation. Most notably, such stable Foxp3 expression was found only for cells displaying enhanced TSDR demethylation. In contrast, in vitro TSDR methylation diminished its transcriptional activity. Foxp3⁺ Treg generated in vivo by DEC-205-mediated targeting of agonist ligands to dendritic cells showed long-term survival in the absence of the inducing antigen and exhibited efficient TSDR demethylation. Together, our data suggest that TSDR is an important methylation-sensitive element regulating Foxp3 expression and demonstrate that epigenetic imprinting in this region is critical for establishment of a stable Treg lineage.Supporting Information for this article is available at www.wiley-vch.de/contents/jc_2040/2008/38105_s.pdf
Compelling evidence suggests that the transcription factor Foxp3 acts as a master switch governing the development and function of CD4(+) regulatory T cells (Tregs). However, whether transcriptional ...control of Foxp3 expression itself contributes to the development of a stable Treg lineage has thus far not been investigated. We here identified an evolutionarily conserved region within the foxp3 locus upstream of exon-1 possessing transcriptional activity. Bisulphite sequencing and chromatin immunoprecipitation revealed complete demethylation of CpG motifs as well as histone modifications within the conserved region in ex vivo isolated Foxp3(+)CD25(+)CD4(+) Tregs, but not in naïve CD25(-)CD4(+) T cells. Partial DNA demethylation is already found within developing Foxp3(+) thymocytes; however, Tregs induced by TGF-beta in vitro display only incomplete demethylation despite high Foxp3 expression. In contrast to natural Tregs, these TGF-beta-induced Foxp3(+) Tregs lose both Foxp3 expression and suppressive activity upon restimulation in the absence of TGF-beta. Our data suggest that expression of Foxp3 must be stabilized by epigenetic modification to allow the development of a permanent suppressor cell lineage, a finding of significant importance for therapeutic applications involving induction or transfer of Tregs and for the understanding of long-term cell lineage decisions.
The scurfy mutant mouse strain suffers from a fatal lymphoproliferative disease leading to early death within 3-4 wk of age. A frame-shift mutation of the forkhead box transcription factor Foxp3 has ...been identified as the molecular cause of this multiorgan autoimmune disease. Foxp3 is a central control element in the development and function of regulatory T cells (T reg cells), which are necessary for the maintenance of self-tolerance. However, it is unclear whether dysfunction or a lack of T reg cells is etiologically involved in scurfy pathogenesis and its human correlate, the IPEX syndrome. We describe the generation of bacterial artificial chromosome-transgenic mice termed "depletion of regulatory T cell" (DEREG) mice expressing a diphtheria toxin (DT) receptor-enhanced green fluorescent protein fusion protein under the control of the foxp3 gene locus, allowing selective and efficient depletion of Foxp3+ T reg cells by DT injection. Ablation of Foxp3+ T reg cells in newborn DEREG mice led to the development of scurfy-like symptoms with splenomegaly, lymphadenopathy, insulitis, and severe skin inflammation. Thus, these data provide experimental evidence that the absence of Foxp3+ T reg cells is indeed sufficient to induce a scurfy-like phenotype. Furthermore, DEREG mice will allow a more precise definition of the function of Foxp3+ T reg cells in immune reactions in vivo.
Soluble guanylate cyclase (sGC), a key enzyme of the nitric oxide signaling pathway, is formed as a heterodimer by various isoforms of its α and β subunit. GUCY1A3 , encoding the α1 subunit, was ...identified as a risk gene for coronary artery disease and myocardial infarction, but its specific contribution to atherosclerosis remains unclear. This study sought to decipher the role of Gucy1a3 in atherosclerosis in mice. At age 32 weeks and after 20 weeks of standard or high-fat diet, Gucy1a3−/− / Ldlr−/− mice exhibited a significant reduction of the atherosclerotic plaque size at the aortic root and the aorta for high-fat diet animals as compared with Ldlr−/− control mice. Collagen content in plaques in the aortic root was reduced, suggesting an alteration of smooth muscle cell function. Proliferation and migration were reduced in Gucy1a3−/− primary aortic smooth muscle cells (AoSMCs) and proliferation was also reduced in human AoSMCs after inhibition of sGC by 1H-1,2,4 oxadiazolo 4,3-a quinoxalin-1-one. Gucy1a3 deficiency in AoSMCs prevents their phenotypic switching, as indicated by the differential expression of marker proteins. The inherited Gucy1a3−/− loss exerts an atheroprotective effect. We suggest that sGC activity promotes the phenotypic switching of smooth muscle cells from a contractile to a synthetic state, fostering the formation of atherosclerosis. Preventing this switch by sGC inhibition may provide a novel target in atherosclerotic disease.
In order to further distinguish unique from general functions of connexin43, we have generated mice in which the coding region of connexin43 was replaced by that of connexin26.
Heterozygous mothers ...showed impaired mammary gland development responsible for decreased lactation and early postnatal death of the pups which could be partially rescued by wild type foster mothers. Only about 17% of the homozygous connexin43 knock-in connexin26 mice instead of 25% expected according to Mendelian inheritance, were born and only 6% survived to day 21 post partum and longer. Neonatal and adult connexin43 knock-in connexin26 mice exhibited slowed ventricular conduction in their hearts, i.e. similar but delayed electrophysiological abnormalities as connexin43 deficient mice. Furthermore, connexin43 knock-in connexin26 male and female mice were infertile and exhibited hypotrophic gonads. In testes, tubuli seminiferi were developed and spermatogonia as well as some primary spermatocytes were present, but further differentiated stages of spermatogenesis were absent. Ovaries of female connexin43 knock-in connexin26 mice revealed only few follicles and the maturation of follicles was completely impaired.
The impaired gametogenesis of homozygous males and females can explain their infertility.
The scurfy mutant mouse strain suffers from a fatal lymphoproliferative disease leading to early death within 3-4 wk of age. A frame-shift mutation of the forkhead box transcription factor Foxp3 has ...been identified as the molecular cause of this multiorgan autoimmune disease. Foxp3 is a central control element in the development and function of regulatory T cells (T reg cells), which are necessary for the maintenance of self-tolerance. However, it is unclear whether dysfunction or a lack of T reg cells is etiologically involved in scurfy pathogenesis and its human correlate, the IPEX syndrome. We describe the generation of bacterial artificial chromosome-transgenic mice termed "depletion of regulatory T cell" (DEREG) mice expressing a diphtheria toxin (DT) receptor-enhanced green fluorescent protein fusion protein under the control of the foxp3 gene locus, allowing selective and efficient depletion of Foxp3 super(+) T reg cells by DT injection. Ablation of Foxp3 super(+) T reg cells in newborn DEREG mice led to the development of scurfy-like symptoms with splenomegaly, lymphadenopathy, insulitis, and severe skin inflammation. Thus, these data provide experimental evidence that the absence of Foxp3 super(+) T reg cells is indeed sufficient to induce a scurfy-like phenotype. Furthermore, DEREG mice will allow a more precise definition of the function of Foxp3 super(+) T reg cells in immune reactions in vivo.
In dieser Arbeit wurde die funktionelle Rolle und Regulation des murinen Transkriptionsfaktor Foxp3 untersucht. Der erste wesentliche Teil zur Analyse der funktionellen Rolle war dabei die Erzeugung ...einer BAC- transgenen Maus. Hierfür wurde ein Zielgenvektor mit der kodierenden Region des eYFPs und einer dualen Selektionskassette sowie die Methode des ET- Klonierens verwendet. Leider war die homologe Rekombination des Zielgenvektors in den BAC nicht erfolgreich. Es kam zu einer ungeklärten Rekombination mit Fremd- DNS. Die Erzeugung der transgenen Maus wurde nach diesem Ergebnis eingestellt, und es wurde mit einer von unserem Kooperationspartner zur Verfügung gestellten BAC- transgenen Maus weitergearbeitet. Diese Maus, die DEREG- Maus, wurde nach dem gleichen Prinzip erstellt, wie die in dieser Arbeit gestartete transgene Maus, an Stelle des eYFPs trägt die DEREG- Maus die kodierenden Region des GFPs und des Diphtheria- Toxin- Rezeptors. Mit dieser Maus wurden erste Analysen zur Überprüfung der transgenen Maus unternommen. Es wurde die Koexpression von GFP und Foxp3, sowie die Depletion der Foxp3+ T- Zellen mittels Diphtheria- Toxin analysiert. Als nächstes wurde die funktionelle Rolle des Transkriptionsfaktors Foxp3 analysiert. Als einer der ersten Schritte wurde die Stabilität von Foxp3 in vivo überprüft und gezeigt, dass T- Zellen, die das Foxp3- Protein exprimieren, bis zu 14 Tage in vivo stabil sind. Weiterhin wurde die Stabilität der Foxp3- Expression in in vitro Kulturen nach Induktion durch TGF-beta untersucht. Die induzierten Tregs zeigten keine stabile Foxp3- Expression und auch bei der Methylierungsanalyse der TSDR zeigten diese T- Zellen nicht das für ex vivo isolierte Foxp3+ T- Zellen beschriebene Methylierungsmuster. Die Stabilität scheint mit der Demethylierung der TSDR zu korrelieren. Die induzierten Tregs zeigten neben dem nicht stabilen Foxp3- Phänotyp auch eine von der Foxp3- Expression abhängige Suppression von naiven Zellen im in vitro Proliferations- Test. Im dritten Teil der Arbeit wurde die Struktur und Regulation des Transkriptionsfaktors Foxp3 untersucht. Der Lokus wurde auf konservierte Regionen im Vergleich zu den Spezies Maus, Mensch, Ratte, Huhn, Schimpanse, Hund und Frosch untersucht. Die in Floess*, Freyer* et al. (63) gefundenen Region TSDR enthält einen hochkonservierten Bereich. Die Region wurde auf mögliche Transkriptionsfaktor- Bindungsstellen hin analysiert, und ebenfalls wurden in diesem Bereich Histon- Modifikationen für die Acetylierung der Histone H3 und H4, sowie Tri- Methylierung des Lysin4 des Histons H3 gefunden. Die TSDR wurde in Luciferase- Tests auf ihre transkriptionelle Aktivität hin getestet und zeigte einem Enhancer ähnliche unterstützende Aktivität. Die Methylierung der TSDR in den Luciferase- Tests führte zu einer Reduktion der transkriptionellen Aktivität. Deletionsmutanten der TSDR konnten den Bereich für die transkriptionelle Aktivität weiter einschränken und zeigten ein 275pb großes Fragment auf, in welchem viele interessante, mögliche Transkriptionsfaktor- Bindungsstellen und auch die größte Anzahl der differentiell methylierten CpG- Motive liegen.
The aim of the study was to analyze the function and regulation of the transcription factor Foxp3. In a first step we designed a BAC-transgenic mouse with eYFP under the control of the Foxp3 promoter. For creating these mice we use the ET- cloning method. The step of homologous recombination of the target vector into the BAC failed. Because of that, we decided to work in cooperation with the group of Tim Sparwasser from Munich and their BAC- transgenic mouse called DEREG- mouse. This mouse expresses the coding region of eGFP fused to the diphtheria- toxin- receptor under the control of the Foxp3 promoter. Therefore Foxp3+ T cells can be easily detected by eGFP expression and can even be depleted by diphtheria- toxin- application. We confirmed the co- expression of Foxp3 and eGFP and furthermore tested the functionality of the depletion- process of Foxp3+ T cells by treatment with diphtheria- toxin. In a second study, we analyzed the stability of Foxp3 expressing cells in vivo. Therefore we transferred Foxp3+ T cells in syngenic mice and analyzed these cells after 14 days for their Foxp3- expression. Furthermore, we tested the induction of Foxp3 expression through TGF-beta and the suppressive activity of these cells. We also analyzed those cells for their methylation pattern, comparing cells, which showed an induction of Foxp3- expression after one week of culture with TGF-beta to cells, which received TGF-beta for one week and were then restimulated in the absence of TGF-beta. The stability of Foxp3 expression seems to correlate with the demethylated state of the TSDR (Treg Specific Demethylated Region). To get a closer look on the region called TSDR in the murine foxp3 locus, we decided to analyze this region under different aspects. First, we checked for putative binding sites of transcription factors by database analysis of the TSDR. We also analysed histon modifications, such as acetylation of histon H3 and H4 and tri- methylation of lysine 4 at histon3, in this region. Presence of these modifications hinted an epigenetic regulation of Foxp3 involving the TSDR. In a last step, the transcriptional activity of TSDR was tested to delineate whether the TSDR serves as an alternative promoter or acts as a regulative element like an enhancer. Luciferase assays showed that TSDR is a regulative enhancer element, which loses transcriptional activity when methylated. Deletion mutants determined the most important fragment of the TSDR.
Treatment outcomes among survivors of cancer diagnosed during adolescence and early young adulthood have not been characterised independently of survivors of cancers diagnosed during childhood. We ...aimed to describe chronic health conditions and all-cause and cause-specific mortality among survivors of early-adolescent and young adult cancer.
The Childhood Cancer Survivor Study (CCSS) is a retrospective cohort study with longitudinal follow-up of 5-year survivors diagnosed with cancer before the age of 21 years at 27 academic institutions in the USA and Canada between 1970 and 1999. We evaluated outcomes among survivors of early-adolescent and young adult cancer (aged 15–20 years at diagnosis) and survivors diagnosed at age younger than 15 years (matched on primary cancer diagnosis, including leukaemia, lymphoma, CNS tumours, neuroblastoma, Wilms tumour, soft-tissue sarcomas, and bone cancer) by comparing both groups to siblings of the same age. Mortality was ascertained with the National Death Index. Chronic health conditions were classified with the Common Terminology Criteria for Adverse Events. Standardised mortality ratios (SMRs) were estimated with age-specific, sex-specific, and calendar year-specific US rates. Cox proportional hazard models estimated hazard ratios (HRs) for chronic health conditions and 95% CIs.
Among 5804 early-adolescent and young adult survivors (median age 42 years, IQR 34–50) the SMR compared to the general population for all-cause mortality was 5·9 (95% CI 5·5–6·2) and among 5804 childhood cancer survivors (median age 34 years; 27–42), it was 6·2 (5·8–6·6). Early-adolescent and young adult survivors had lower SMRs for death from health-related causes (ie, conditions that exclude recurrence or progression of the primary cancer and external causes, but include the late effects of cancer therapy) than did childhood cancer survivors (SMR 4·8 95% CI 4·4–5·1 vs 6·8 6·2–7·4), which was primarily evident more than 20 years after cancer diagnosis. Early-adolescent and young adult cancer survivors and childhood cancer survivors were both at greater risk of developing severe and disabling, life-threatening, or fatal (grade 3–5) health conditions than siblings of the same age (HR 4·2 95% CI 3·7–4·8 for early adolescent and young adult cancer survivors and 5·6 4·9–6·3 for childhood cancer survivors), and at increased risk of developing grade 3–5 cardiac (4·3 3·5–5·4 and 5·6 4·5–7·1), endocrine (3·9 2·9–5·1 and 6·4 5·1–8·0), and musculoskeletal conditions (6·5 3·9–11·1 and 8·0 4·6–14·0) when compared with siblings of the same age, although all these risks were lower for early-adolescent and young adult survivors than for childhood cancer survivors.
Early-adolescent and young adult cancer survivors had higher risks of mortality and severe and life threatening chronic health conditions than the general population. However, early-adolescent and young adult cancer survivors had lower non-recurrent, health-related SMRs and relative risks of developing grade 3–5 chronic health conditions than childhood cancer survivors, by comparison with siblings of the same age, which were most notable more than 20 years after their original cancer. These results highlight the need for long-term screening of both childhood and early-adolescent and young adult cancer survivors.
National Cancer Institute and American Lebanese-Syrian Associated Charities.
Abstract
Background
Patient-reported outcome (PRO) measurements linked to Common Terminology Criteria for Adverse Events (CTCAE) grading may improve symptom adverse event (AE) reporting in pediatric ...oncology trials. We evaluated construct validity, responsiveness, and test-retest reliability of the Ped-PRO–CTCAE measurement system for children and adolescents undergoing cancer care.
Methods
A total of 482 children and adolescents (7–18 years, 41.5% not non-Hispanic white) newly diagnosed with cancer and their caregivers participated from nine pediatric oncology hospitals. Surveys were completed at 72 hours preceding treatment initiation (T1) and at follow-up (T2) approximately 7–17 days later for chemotherapy, and 4+ weeks for radiation. Psychometric analyses examined the relationship of Ped-PRO-CTCAE items (assessing 62 symptom AEs) with Patient-Reported Outcomes Measurement Information System, Memorial Symptom Assessment Scale, Lansky Play-Performance Scale, and medication use. A separate test-retest study included 46 children.
Results
Ped-PRO-CTCAE and Memorial Symptom Assessment Scale were strongly correlated across age groups at T2: 7–12 years (r = 0.62–0.80), 13–15 years (r = 0.44–0.94), and 16–18 years (r = 0.65–0.98); and over time. The Ped-PRO-CTCAE was strongly correlated with Patient-Reported Outcomes Measurement Information System Pediatric measures at T2; for example, pain interference (r = 0.70, 95% confidence interval CI = 0.64 to 0.76), fatigue severity (r = 0.63, 95% CI = 0.56 to 0.69), and depression severity (r = 0.76, 95% CI = 0.71 to 0.81). Ped-PRO-CTCAE items differentiated children by Lansky Play-Performance Scale and by medication use. Test-retest agreement ranged from 54.3% to 93.5%.
Conclusions
This longitudinal study provided evidence for the construct validity and reliability of the core Ped-PRO-CTCAE symptom AE items relative to several established measures. Additional responsiveness data with clinical anchors are recommended. Incorporation of Ped-PRO-CTCAE in trials may lead to a better understanding of the cancer treatment experience.
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