Objective
Systemic juvenile idiopathic arthritis (JIA) is a multifactorial autoinflammatory disease with a historically poor prognosis. With current treatment regimens, approximately half of patients ...still experience active disease after 1 year of therapy. This study was undertaken to evaluate a treat‐to‐target approach using recombinant interleukin‐1 receptor antagonist (rIL‐1Ra; anakinra) as first‐line monotherapy to achieve early inactive disease and prevent damage.
Methods
In this single‐center, prospective study, patients with new‐onset systemic JIA with an unsatisfactory response to nonsteroidal antiinflammatory drugs received rIL‐1Ra monotherapy according to a treat‐to‐target strategy. Patients with an incomplete response to 2 mg/kg rIL‐1Ra subsequently received 4 mg/kg rIL‐1Ra or additional prednisolone, or switched to alternative therapy. For patients in whom inactive disease was achieved, rIL‐1Ra was tapered after 3 months and subsequently stopped.
Results
Forty‐two patients, including 12 who had no arthritis at disease onset, were followed up for a median of 5.8 years. The median time to achieve inactive disease was 33 days. At 1 year, 76% had inactive disease, and 52% had inactive disease while not receiving medication. High neutrophil counts at baseline and a complete response after 1 month of rIL‐1Ra were highly associated with inactive disease at 1 year. After 5 years of follow‐up, 96% of the patients included had inactive disease, and 75% had inactive disease while not receiving medication. Articular or extraarticular damage was reported in <5%, and only 33% of the patients received glucocorticoids. Treatment with rIL‐1Ra was equally effective in systemic JIA patients without arthritis at disease onset.
Conclusion
Treatment to target, starting with first‐line, short‐course monotherapy with rIL‐1Ra, is a highly efficacious strategy to induce and sustain inactive disease and to prevent disease‐ and glucocorticoid‐related damage in systemic JIA.
Epidermal growth factor receptor (EGFR) is known to be critically involved in tissue development and homeostasis as well as in the pathogenesis of cancer. Here we showed that Foxp3+ regulatory T ...(Treg) cells express EGFR under inflammatory conditions. Stimulation with the EGF-like growth factor Amphiregulin (AREG) markedly enhanced Treg cell function in vitro, and in a colitis and tumor vaccination model we showed that AREG was critical for efficient Treg cell function in vivo. In addition, mast cell-derived AREG fully restored optimal Treg cell function. These findings reveal EGFR as a component in the regulation of local immune responses and establish a link between mast cells and Treg cells. Targeting of this immune regulatory mechanism may contribute to the therapeutic successes of EGFR-targeting treatments in cancer patients.
▸ Regulatory T (Treg) cells express EGFR ▸ Amphiregulin (AREG) enhances Treg cell function in in vitro suppression assays ▸ AREG enhances Treg cell function in vivo in a colitis and a tumor vaccination model ▸ Mast cell-derived AREG can fully restore optimal Treg cell function
Treg cells are critical regulators of immune homeostasis, and environment-driven Treg cell differentiation into effector (e)Treg cells is crucial for optimal functioning. However, human Treg cell ...programming in inflammation is unclear. Here, we combine transcriptional and epigenetic profiling to identify a human eTreg cell signature. Inflammation-derived functional Treg cells have a transcriptional profile characterized by upregulation of both a core Treg cell (FOXP3, CTLA4, TIGIT) and effector program (GITR, BLIMP-1, BATF). We identify a specific human eTreg cell signature that includes the vitamin D receptor (VDR) as a predicted regulator in eTreg cell differentiation. H3K27ac/H3K4me1 occupancy indicates an altered (super-)enhancer landscape, including enrichment of the VDR and BATF binding motifs. The Treg cell profile has striking overlap with tumor-infiltrating Treg cells. Our data demonstrate that human inflammation-derived Treg cells acquire a conserved and specific eTreg cell profile guided by epigenetic changes, and fine-tuned by environment-specific adaptations.
Stable Foxp3 expression is required for the development of functional regulatory T (Treg) cells. Here, we demonstrate that the expression of the transcription factor Foxp3 can be regulated through ...the polyubiquitination of multiple lysine residues, resulting in proteasome-mediated degradation. Expression of the deubiquitinase (DUB) USP7 was found to be upregulated and active in Treg cells, being associated with Foxp3 in the nucleus. Ectopic expression of USP7 decreased Foxp3 polyubiquitination and increased Foxp3 expression. Conversely, either treatment with DUB inhibitor or USP7 knockdown decreased endogenous Foxp3 protein expression and decreased Treg-cell-mediated suppression in vitro. Furthermore, in a murine adoptive-transfer-induced colitis model, either inhibition of DUB activity or USP7 knockdown in Treg cells abrogated their ability to resolve inflammation in vivo. Our data reveal a molecular mechanism in which rapid temporal control of Foxp3 expression in Treg cells can be regulated by USP7, thereby modulating Treg cell numbers and function.
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•DUBs regulate Foxp3 protein expression through the inhibition of degradation•Expression of the DUB USP7 is selectively upregulated during Treg cell differentiation•Foxp3 protein expression is increased by USP7-mediated Foxp3 deubiquitination•USP7 modulates Treg-cell-mediated suppression both in vitro and in vivo
Objective
Neutrophils are the most abundant innate immune cells in the blood, but little is known about their role in (acquired) chronic autoinflammatory diseases. This study was undertaken to ...investigate the role of neutrophils in systemic‐onset juvenile idiopathic arthritis (JIA), a prototypical multifactorial autoinflammatory disease that is characterized by arthritis and severe systemic inflammation.
Methods
Fifty patients with systemic‐onset JIA who were receiving treatment with recombinant interleukin‐1 receptor antagonist (rIL‐1Ra; anakinra) were analyzed at disease onset and during remission. RNA sequencing was performed on fluorescence‐activated cell–sorted neutrophils from 3 patients with active systemic‐onset JIA and 3 healthy controls. Expression of activation markers, apoptosis, production of reactive oxygen species (ROS), and degranulation of secretory vesicles from neutrophils were assessed by flow cytometry in serum samples from 17 patients with systemic‐onset JIA and 15 healthy controls.
Results
Neutrophil counts were markedly increased at disease onset, and this correlated with the levels of inflammatory mediators. The neutrophil counts normalized within days after the initiation of rIL‐1Ra therapy. RNA‐sequencing analysis revealed a substantial up‐regulation of inflammatory processes in neutrophils from patients with active systemic‐onset JIA, significantly overlapping with the transcriptome of sepsis. Correspondingly, neutrophils from patients with active systemic‐onset JIA displayed a primed phenotype that was characterized by increased ROS production, CD62L shedding, and secretory vesicle degranulation, which was reversed by rIL‐1Ra treatment in patients who had achieved clinical remission. Patients with a short disease duration had high neutrophil counts, more immature neutrophils, and a complete response to rIL‐1Ra, whereas patients with symptoms for >1 month had normal neutrophil counts and an unsatisfactory response to rIL‐1Ra. In vitro, rIL‐1Ra antagonized the priming effect of IL‐1β on neutrophils from healthy subjects.
Conclusion
These results strongly support the notion that neutrophils play an important role in systemic‐onset JIA, especially in the early inflammatory phase of the disease. The findings also demonstrate that neutrophil numbers and the inflammatory activity of systemic‐onset JIA are both susceptible to IL‐1 blockade.
Highlights • PTMs including acetylation, ubiquitination, and phosphorylation can decorate FoxP3. • PTMs affect FoxP3 DNA binding, transcriptional activation, and proteasomal degradation. • PTMs may ...enable transient regulation of FoxP3 function in response to environmental cues. • A holistic understanding of how these PTMs regulate FoxP3 function in vivo is necessary.
When a T cell and an antigen-presenting cell form an immunological synapse, rapid dynein-driven translocation of the centrosome toward the contact site leads to reorganization of microtubules and ...associated organelles. Currently, little is known about how the regulation of microtubule dynamics contributes to this process. Here, we show that the knockout of KIF21B, a kinesin-4 linked to autoimmune disorders, causes microtubule overgrowth and perturbs centrosome translocation. KIF21B restricts microtubule length by inducing microtubule pausing typically followed by catastrophe. Catastrophe induction with vinblastine prevented microtubule overgrowth and was sufficient to rescue centrosome polarization in KIF21B-knockout cells. Biophysical simulations showed that a relatively small number of KIF21B molecules can restrict mirotubule length and promote an imbalance of dynein-mediated pulling forces that allows the centrosome to translocate past the nucleus. We conclude that proper control of microtubule length is important for allowing rapid remodeling of the cytoskeleton and efficient T cell polarization.
The underlying molecular mechanisms for many autoimmune diseases are poorly understood. Juvenile idiopathic arthritis (JIA) is an exceptionally well-suited model for studying autoimmune diseases due ...to its early onset and the possibility to analyze cells derived from the site of inflammation. Epigenetic profiling, utilizing primary JIA patient-derived cells, can contribute to the understanding of autoimmune diseases. With H3K27ac chromatin immunoprecipitation, we identified a disease-specific, inflammation-associated, typical enhancer and super-enhancer signature in JIA patient synovial-fluid-derived CD4+ memory/effector T cells. RNA sequencing of autoinflammatory site-derived patient T cells revealed that BET inhibition, utilizing JQ1, inhibited immune-related super-enhancers and preferentially reduced disease-associated gene expression, including cytokine-related processes. Altogether, these results demonstrate the potential use of enhancer profiling to identify disease mediators and provide evidence for BET inhibition as a possible therapeutic approach for the treatment of autoimmune diseases.
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•Identification of a disease-specific, inflammation-associated, enhancer signature•Inflammatory-site-derived cells are epigenetically different from peripheral cells•Enrichment of disease-related SNPs in disease-associated super-enhancers•BET inhibition of JIA patient T cells preferentially reduced JIA gene expression
By defining the active super-enhancer profile of autoimmune disease patients, Peeters et al. identify a disease-specific, inflammation-associated super-enhancer signature. In addition, inhibition of super-enhancer activity, using a BET inhibitor, in autoimmune disease patient-derived cells preferentially reduced disease-associated gene expression. These findings suggest a role for enhancers and super-enhancers in autoimmune diseases and demonstrates the potential use of BET inhibitors for the treatment of such diseases.
Foxp3 is crucial for both the development and function of regulatory T (Treg) cells; however, the posttranslational mechanisms regulating Foxp3 transcriptional output remain poorly defined. Here, we ...demonstrate that T cell factor 1 (TCF1) and Foxp3 associates in Treg cells and that active Wnt signaling disrupts Foxp3 transcriptional activity. A global chromatin immunoprecipitation sequencing comparison in Treg cells revealed considerable overlap between Foxp3 and Wnt target genes. The activation of Wnt signaling reduced Treg-mediated suppression both in vitro and in vivo, whereas disruption of Wnt signaling in Treg cells enhanced their suppressive capacity. The activation of effector T cells increased Wnt3a production, and Wnt3a levels were found to be greatly increased in mononuclear cells isolated from synovial fluid versus peripheral blood of arthritis patients. We propose a model in which Wnt produced under inflammatory conditions represses Treg cell function, allowing a productive immune response, but, if uncontrolled, could lead to the development of autoimmunity.
•TCF/β-catenin and Foxp3 share common transcriptional targets•Wnt signaling negatively modulates Foxp3 transcriptional activity•Wnt signaling reduces Treg-cell-mediated suppression in vitro and in vivo•Wnt production is increased upon the activation of T cells and at inflammatory loci
Objective
Tregs are crucial for immune regulation, and environment‐driven adaptation of effector (e)Tregs is essential for local functioning. However, the extent of human Treg heterogeneity in ...inflammatory settings is unclear.
Methods
We combined single‐cell RNA‐ and TCR‐sequencing on Tregs derived from three to six patients with juvenile idiopathic arthritis (JIA) to investigate the functional heterogeneity of human synovial fluid (SF)‐derived Tregs from inflamed joints. Confirmation and suppressive function of the identified Treg clusters was assessed by flow cytometry.
Results
Four Treg clusters were identified; incoming, activated eTregs with either a dominant suppressive or cytotoxic profile, and GPR56+CD161+CXCL13+ Tregs. Pseudotime analysis showed differentiation towards either classical eTreg profiles or GPR56+CD161+CXCL13+ Tregs supported by TCR data. Despite its most differentiated phenotype, GPR56+CD161+CXCL13+ Tregs were shown to be suppressive. Furthermore, BATF was identified as an overarching eTreg regulator, with the novel Treg‐associated regulon BHLHE40 driving differentiation towards GPR56+CD161+CXCL13+ Tregs, and JAZF1 towards classical eTregs.
Conclusion
Our study reveals a heterogeneous population of Tregs at the site of inflammation in JIA. SF Treg differentiate to a classical eTreg profile with a more dominant suppressive or cytotoxic profile that share a similar TCR repertoire, or towards GPR56+CD161+CXCL13+ Tregs with a more distinct TCR repertoire. Genes characterising GPR56+CD161+CXCL13+ Tregs were also mirrored in other T‐cell subsets in both the tumor and the autoimmune setting. Finally, the identified key regulators driving SF Treg adaptation may be interesting targets for autoimmunity or tumor interventions.
We show that human regulatory T cells (Tregs) within the inflamed arthritic joint differentiate locally and are functionally heterogeneous. Tregs differentiate towards either classical effector Tregs or towards GRP56+CD161+CXCL13+ Tregs, supported by TCR data. Novel predicted drivers of local Treg differentiation include JAZF1 for classical effector Tregs and BHLHE40 for GRP56+CD161+CXCL13+ Tregs.
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