Publications by authors named "Ilgiz A Mufazalov"

20 Publications

  • Page 1 of 1

IL-17 controls central nervous system autoimmunity through the intestinal microbiome.

Sci Immunol 2021 Feb;6(56)

Institute for Molecular Medicine, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany.

Interleukin-17A- (IL-17A) and IL-17F-producing CD4 T helper cells (T17 cells) are implicated in the development of chronic inflammatory diseases, such as multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE). T17 cells also orchestrate leukocyte invasion of the central nervous system (CNS) and subsequent tissue damage. However, the role of IL-17A and IL-17F as effector cytokines is still confused with the encephalitogenic function of the cells that produce these cytokines, namely, T17 cells, fueling a long-standing debate in the neuroimmunology field. Here, we demonstrated that mice deficient for IL-17A/F lose their susceptibility to EAE, which correlated with an altered composition of their gut microbiota. However, loss of IL-17A/F in T cells did not diminish their encephalitogenic capacity. Reconstitution of a wild-type-like intestinal microbiota or reintroduction of IL-17A specifically into the gut epithelium of IL-17A/F-deficient mice reestablished their susceptibility to EAE. Thus, our data demonstrated that IL-17A and IL-17F are not encephalitogenic mediators but rather modulators of intestinal homeostasis that indirectly alter CNS-directed autoimmunity.
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http://dx.doi.org/10.1126/sciimmunol.aaz6563DOI Listing
February 2021

Regulatory T cell control of systemic immunity and immunotherapy response in liver metastasis.

Sci Immunol 2020 10;5(52)

Sean N. Parker Autoimmune Research Laboratory, University of California, San Francisco, San Francisco, CA 94143, USA.

Patients with cancer with liver metastasis demonstrate significantly worse outcomes than those without liver metastasis when treated with anti-PD-1 immunotherapy. The mechanism of liver metastases-induced reduction in systemic antitumor immunity is unclear. Using a dual-tumor immunocompetent mouse model, we found that the immune response to tumor antigen presence within the liver led to the systemic suppression of antitumor immunity. The immune suppression was antigen specific and associated with the coordinated activation of regulatory T cells (T) and modulation of intratumoral CD11b monocytes. The dysfunctional immune state could not be reversed by anti-PD-1 monotherapy unless T cells were depleted (anti-CTLA-4) or destabilized (EZH2 inhibitor). Thus, this study provides a mechanistic understanding and rationale for adding T and CD11b monocyte targeting agents in combination with anti-PD-1 to treat patients with cancer with liver metastasis.
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http://dx.doi.org/10.1126/sciimmunol.aba0759DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7755924PMC
October 2020

Interleukin-1 promotes autoimmune neuroinflammation by suppressing endothelial heme oxygenase-1 at the blood-brain barrier.

Acta Neuropathol 2020 10 11;140(4):549-567. Epub 2020 Jul 11.

Institute for Molecular Medicine, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany.

The proinflammatory cytokine interleukin 1 (IL-1) is crucially involved in the pathogenesis of multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis (EAE). Herein, we studied the role of IL-1 signaling in blood-brain barrier (BBB) endothelial cells (ECs), astrocytes and microglia for EAE development, using mice with the conditional deletion of its signaling receptor IL-1R1. We found that IL-1 signaling in microglia and astrocytes is redundant for the development of EAE, whereas the IL-1R1 deletion in BBB-ECs markedly ameliorated disease severity. IL-1 signaling in BBB-ECs upregulated the expression of the adhesion molecules Vcam-1, Icam-1 and the chemokine receptor Darc, all of which have been previously shown to promote CNS-specific inflammation. In contrast, IL-1R1 signaling suppressed the expression of the stress-responsive heme catabolizing enzyme heme oxygenase-1 (HO-1) in BBB-ECs, promoting disease progression via a mechanism associated with deregulated expression of the IL-1-responsive genes Vcam1, Icam1 and Ackr1 (Darc). Mechanistically, our data emphasize a functional crosstalk of BBB-EC IL-1 signaling and HO-1, controlling the transcription of downstream proinflammatory genes promoting the pathogenesis of autoimmune neuroinflammation.
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http://dx.doi.org/10.1007/s00401-020-02187-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7498485PMC
October 2020

Cell-specific conditional deletion of interleukin-1 (IL-1) ligands and its receptors: a new toolbox to study the role of IL-1 in health and disease.

J Mol Med (Berl) 2020 07 29;98(7):923-930. Epub 2020 May 29.

Institute for Molecular Medicine, University Medical Center of the Johannes Gutenberg-University of Mainz, Langenbeckstrasse 1, Building 308A, 55131, Mainz, Germany.

The pro-inflammatory cytokine interleukin-1 (IL-1) plays a key role in many physiological processes and during the inflammatory and immune response to most common diseases. IL-1 exists as two agonists, IL-1α and IL-1β that bind to the only signaling IL-1 type 1 receptor (IL-1R1), while a second decoy IL-1 type 2 receptor (IL-1R2) binds both forms of IL-1 without inducing cell signaling. The field of immunology and inflammation research has, over the past 35 years, unraveled many mechanisms of IL-1 actions, through in vitro manipulation of the IL-1 system or by using genetically engineered mouse models that lack either member of the IL-1 family in ubiquitous constitutive manner. However, the limitation of global mouse knockout technology has significantly hampered our understanding of the precise mechanisms of IL-1 actions in animal models of disease. Here we report and review the recent generation of new conditional mouse mutants in which exons of Il1a, Il1b, Il1r1, and Il1r2 genes flanked by loxP sites () can be deleted in cell-/tissue-specific constitutive or inducible manner by Cre recombinase expression. Hence, IL-1α, IL-1β, IL-1R1, and IL-1R2 mice constitute a new toolbox that will provide a step change in our understanding of the cell-specific role of IL-1 and its receptor in health and disease and the potential development of targeted IL-1 therapies.
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http://dx.doi.org/10.1007/s00109-020-01928-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7343756PMC
July 2020

Recirculating IL-1R2 Tregs fine-tune intrathymic Treg development under inflammatory conditions.

Cell Mol Immunol 2021 Jan 27;18(1):182-193. Epub 2020 Jan 27.

Department of Experimental Immunology, Helmholtz Centre for Infection Research, Braunschweig, Germany.

The vast majority of Foxp3 regulatory T cells (Tregs) are generated in the thymus, and several factors, such as cytokines and unique thymic antigen-presenting cells, are known to contribute to the development of these thymus-derived Tregs (tTregs). Here, we report the existence of a specific subset of Foxp3 Tregs within the thymus that is characterized by the expression of IL-1R2, which is a decoy receptor for the inflammatory cytokine IL-1. Detailed flow cytometric analysis of the thymocytes from Foxp3xRAG1 reporter mice revealed that the IL-1R2 Tregs are mainly RAG1 and CCR6CCR7, demonstrating that these Tregs are recirculating cells entering the thymus from the periphery and that they have an activated phenotype. In the spleen, the majority of IL-1R2 Tregs express neuropilin-1 (Nrp-1) and Helios, suggesting a thymic origin for these Tregs. Interestingly, among all tissues studied, the highest frequency of IL-1R2 Tregs was observed in the thymus, indicating preferential recruitment of this Treg subset by the thymus. Using fetal thymic organ cultures (FTOCs), we demonstrated that increased concentrations of exogenous IL-1β blocked intrathymic Treg development, resulting in a decreased frequency of CD25Foxp3 tTregs and an accumulation of CD25Foxp3 Treg precursors. Interestingly, the addition of IL-1R2 Tregs, but not IL-1R2 Tregs, to reaggregated thymic organ cultures (RTOCs) abrogated the IL-1β-mediated blockade, demonstrating that these recirculating IL-1R2 Tregs can quench IL-1 signaling in the thymus and thereby maintain thymic Treg development even under inflammatory conditions.
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http://dx.doi.org/10.1038/s41423-019-0352-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7853075PMC
January 2021

Cutting Edge: IL-6-Driven Immune Dysregulation Is Strictly Dependent on IL-6R α-Chain Expression.

J Immunol 2020 02 10;204(4):747-751. Epub 2020 Jan 10.

Institute for Molecular Medicine, University Medical Center of the Johannes Gutenberg-University Mainz, 55131 Mainz, Germany.

IL-6 binds to the IL-6R α-chain (IL-6Rα) and signals via the signal transducer gp130. Recently, IL-6 was found to also bind to the cell surface glycoprotein CD5, which would then engage gp130 in the absence of IL-6Rα. However, the biological relevance of this alternative pathway is under debate. In this study, we developed a mouse model, in which murine IL-6 is overexpressed in a CD11c-Cre-dependent manner. Transgenic mice developed a lethal immune dysregulation syndrome with increased numbers of Ly-6G neutrophils and Ly-6C monocytes/macrophages. IL-6 overexpression promoted activation of CD4 T cells while suppressing CD5 B-1a cell development. However, additional ablation of IL-6Rα protected IL-6-overexpressing mice from IL-6-triggered inflammation and fully phenocopied IL-6Rα-deficient mice without IL-6 overexpression. Mechanistically, IL-6Rα deficiency completely prevented downstream activation of STAT3 in response to IL-6. Altogether, our data clarify that IL-6Rα is the only biologically relevant receptor for IL-6 in mice.
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http://dx.doi.org/10.4049/jimmunol.1900876DOI Listing
February 2020

Cell-Type-Specific Responses to Interleukin-1 Control Microbial Invasion and Tumor-Elicited Inflammation in Colorectal Cancer.

Immunity 2019 01;50(1):166-180.e7

Cancer Prevention and Control Program, Fox Chase Cancer Center, Philadelphia, PA, 19111, USA. Electronic address:

Chronic inflammation drives the progression of colorectal cancer (CRC). Increased expression of interleukin (IL)-17A is associated with poor prognosis, and IL-17A blockade curbs tumor progression in preclinical models of CRC. Here we examined the impact of IL-1 signaling, a key regulator of the IL-17 pathway, in different cell types within the CRC microenvironment. Genetic deletion of the IL-1 receptor (IL-1R1) in epithelial cells alleviated tumorigenesis in the APC model of CRC, demonstrating a cell-autonomous role for IL-1 signaling in early tumor seed outgrowth. T cell specific ablation of IL-1R1 decreased tumor-elicited inflammation dependent on IL-17 and IL-22, thereby reducing CRC progression. The pro-tumorigenic roles of IL-1 were counteracted by its effects on myeloid cells, particularly neutrophils, where IL-1R1 ablation resulted in bacterial invasion into tumors, heightened inflammation and aggressive CRC progression. Thus, IL-1 signaling elicits cell-type-specific responses, which, in aggregate, set the inflammatory tone of the tumor microenvironment and determine the propensity for disease progression.
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http://dx.doi.org/10.1016/j.immuni.2018.11.015DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6490968PMC
January 2019

Intrinsic TNFR2 signaling in T regulatory cells provides protection in CNS autoimmunity.

Proc Natl Acad Sci U S A 2018 12 29;115(51):13051-13056. Epub 2018 Nov 29.

Laboratory of Molecular Mechanisms of Immunity, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia;

TNF is a multifunctional cytokine involved in autoimmune disease pathogenesis that exerts its effects through two distinct TNF receptors, TNFR1 and TNFR2. While TNF- and TNFR1-deficient (but not TNFR2-deficient) mice show very similar phenotypes, the significance of TNFR2 signaling in health and disease remains incompletely understood. Recent studies implicated the importance of the TNF/TNFR2 axis in T regulatory (T) cell functions. To definitively ascertain the significance of TNFR2 signaling, we generated and validated doubly humanized TNF/TNFR2 mice, with the option of conditional inactivation of TNFR2. These mice carry a functional human TNF-TNFR2 (hTNF-hTNFR2) signaling module and provide a useful tool for comparative evaluation of TNF-directed biologics. Conditional inactivation of TNFR2 in FoxP3 cells in doubly humanized TNF/TNFR2 mice down-regulated the expression of T signature molecules (such as FoxP3, CD25, CTLA-4, and GITR) and diminished T suppressive function in vitro. Consequently, T-restricted TNFR2 deficiency led to significant exacerbation of experimental autoimmune encephalomyelitis (EAE), accompanied by reduced capacity to control Th17-mediated immune responses. Our findings expose the intrinsic and beneficial effects of TNFR2 signaling in T cells that could translate into protective functions in vivo, including treatment of autoimmunity.
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http://dx.doi.org/10.1073/pnas.1807499115DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6304938PMC
December 2018

Regulation of IL-1 signaling by the decoy receptor IL-1R2.

J Mol Med (Berl) 2018 10 15;96(10):983-992. Epub 2018 Aug 15.

Institute for Molecular Medicine, University Medical Center of the Johannes Gutenberg-University Mainz, Langenbeckstrasse 1, 55131, Mainz, Germany.

The pleiotropic cytokine IL-1 mediates its biological functions via association with the signaling receptor IL-1R1. Despite an apparent simplicity in IL-1 signaling activation, multiple negative regulators have been identified. The decoy receptor IL-1R2 (also known as CD121b) can suppress IL-1 maturation, sequester its active forms or hinder the signaling complex assembly. IL-1R2 is differentially expressed among numerous cell types and displays cis- and trans- modes of action. In this review, we link different forms of IL-1R2 (membrane-bound (mIL-1R2), secreted (sIL-1R2), shedded (shIL-1R2), cytoplasmic, and intracellular domain (IL-1R2) restricted) with their ability to interfere with IL-1, thereby regulating immune responses. We also discuss the intriguing possible function of IL-1R2 as a transcriptional regulator. Finally, we summarize the known impact of IL-1R2 in disease pathogenesis and discuss its potential role in treatment of inflammatory conditions.
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http://dx.doi.org/10.1007/s00109-018-1684-zDOI Listing
October 2018

Expression of IL-17F is associated with non-pathogenic Th17 cells.

J Mol Med (Berl) 2018 08 29;96(8):819-829. Epub 2018 Jun 29.

University Medical Center of the Johannes Gutenberg University Mainz, Institute for Molecular Medicine, 55131, Mainz, Germany.

IL-17A and IL-17F share the highest sequence homology of the IL-17 family and signal via the same IL-17RA/RC receptor heterodimer. To better explore the expression of these two cytokines, we used a double reporter mouse strain (IL-17 mice), where IL-17A expressing cells are marked by enhanced green fluorescent protein (eGFP) while red fluorescence protein (RFP) reports the expression of IL-17F. In steady state, we found that Th17 and γδ T cells only expressed IL-17A, while IL-17F expression was restricted to CD8 T cells (Tc17) and innate lymphoid cells (ILC type 3) of the gut. In experimental autoimmune encephalomyelitis, the vast majority of CNS-infiltrating Th17 cells expressed IL-17A but not IL-17F. In contrast, anti-CD3-induced, TGF-β-driven Th17 cells in the gut expressed both of these IL-17 cytokines. In line with this, in vitro differentiation of Th17 cells in the presence of IL-1β led primarily to IL-17A expressing T cells, while TGF-β induced IL-17F co-expressing Th17 cells. Our results suggest that expression of IL-17F is associated with non-pathogenic T cells, pointing to a differential function of IL-17A versus IL-17F.

Key Messages: Naïve mice: CD4 T cells and γδ T cells express IL-17A, and Tc17 cells express IL-17F. Gut ILC3 show differential expression of IL17A and F. Th17 differentiation with TGF-β1 induces IL-17A and F, whereas IL-1β induced cells expressing IL-17A. Th17 cells in EAE in CNS express IL-17A only. Gut Th17 cells induced by anti-CD3 express IL-17A and F together as skin γδ T cells of IMQ-treated mice.
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http://dx.doi.org/10.1007/s00109-018-1662-5DOI Listing
August 2018

Oral epithelial cells orchestrate innate type 17 responses to through the virulence factor candidalysin.

Sci Immunol 2017 11;2(17)

Division of Rheumatology and Clinical Immunology, University of Pittsburgh, Pittsburgh, PA 15261, USA.

is a dimorphic commensal fungus that causes severe oral infections in immunodeficient patients. Invasion of hyphae into oral epithelium is an essential virulence trait. Interleukin-17 (IL-17) signaling is required for both innate and adaptive immunity to During the innate response, IL-17 is produced by γδ T cells and a poorly understood population of innate-acting CD4 αβ T cell receptor (TCRαβ) cells, but only the TCRαβ cells expand during acute infection. Confirming the innate nature of these cells, the TCR was not detectably activated during the primary response, as evidenced by mice that report antigen-specific signaling through the TCR. Rather, the expansion of innate TCRαβ cells was driven by both intrinsic and extrinsic IL-1R signaling. Unexpectedly, there was no requirement for CCR6/CCL20-dependent recruitment or prototypical fungal pattern recognition receptors. However, mutants that cannot switch from yeast to hyphae showed impaired TCRαβ cell proliferation and expression. This prompted us to assess the role of candidalysin, a hyphal-associated peptide that damages oral epithelial cells and triggers production of inflammatory cytokines including IL-1. Candidalysin-deficient strains failed to up-regulate or drive the proliferation of innate TCRαβ cells. Moreover, candidalysin signaled synergistically with IL-17, which further augmented the expression of IL-1α/β and other cytokines. Thus, IL-17 and , via secreted candidalysin, amplify inflammation in a self-reinforcing feed-forward loop. These findings challenge the paradigm that hyphal formation per se is required for the oral innate response and demonstrate that establishment of IL-1- and IL-17-dependent innate immunity is induced by tissue-damaging hyphae.
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http://dx.doi.org/10.1126/sciimmunol.aam8834DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5881387PMC
November 2017

A T cell-specific deletion of HDAC1 protects against experimental autoimmune encephalomyelitis.

J Autoimmun 2018 01 28;86:51-61. Epub 2017 Sep 28.

Division of Immunobiology, Institute of Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, 1090 Vienna, Austria. Electronic address:

Multiple sclerosis (MS) is a human neurodegenerative disease characterized by the invasion of autoreactive T cells from the periphery into the CNS. Application of pan-histone deacetylase inhibitors (HDACi) ameliorates experimental autoimmune encephalomyelitis (EAE), an animal model for MS, suggesting that HDACi might be a potential therapeutic strategy for MS. However, the function of individual HDAC members in the pathogenesis of EAE is not known. In this study we report that mice with a T cell-specific deletion of HDAC1 (using the Cd4-Cre deleter strain; HDAC1-cKO) were completely resistant to EAE despite the ability of HDAC1cKO CD4 T cells to differentiate into Th17 cells. RNA sequencing revealed STAT1 as a prominent upstream regulator of differentially expressed genes in activated HDAC1-cKO CD4 T cells and this was accompanied by a strong increase in phosphorylated STAT1 (pSTAT1). This suggests that HDAC1 controls STAT1 activity in activated CD4 T cells. Increased pSTAT1 levels correlated with a reduced expression of the chemokine receptors Ccr4 and Ccr6, which are important for the migration of T cells into the CNS. Finally, EAE susceptibility was restored in WT:HDAC1-cKO mixed BM chimeric mice, indicating a cell-autonomous defect. Our data demonstrate a novel pathophysiological role for HDAC1 in EAE and provide evidence that selective inhibition of HDAC1 might be a promising strategy for the treatment of MS.
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http://dx.doi.org/10.1016/j.jaut.2017.09.008DOI Listing
January 2018

Balanced Bcl-3 expression in murine CD4 T cells is required for generation of encephalitogenic Th17 cells.

Eur J Immunol 2017 08 29;47(8):1335-1341. Epub 2017 Jun 29.

Institute for Molecular Medicine, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany.

The function of NF-κB family members is controlled by multiple mechanisms including the transcriptional regulator Bcl-3, an atypical member of the IκB family. By using a murine model of conditional Bcl-3 overexpression specifically in T cells, we observed impairment in the development of Th2, Th1, and Th17 cells. High expression of Bcl-3 promoted CD4 T-cell survival, but at the same time suppressed proliferation in response to TCR stimulation, resulting in reduced CD4 T-cell expansion. As a consequence, T-cell-specific overexpression of Bcl-3 led to reduced inflammation in the small intestine of mice applied with anti-CD3 in a model of gut inflammation. Moreover, impaired Th17-cell development resulted in the resistance of Bcl-3 overexpressing mice to EAE, a mouse model of multiple sclerosis. Thus, we concluded that fine-tuning expression of Bcl-3 is needed for proper CD4 T-cell development and is required to sustain Th17-cell mediated pathology.
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http://dx.doi.org/10.1002/eji.201746933DOI Listing
August 2017

Elevated levels of Bcl-3 inhibits Treg development and function resulting in spontaneous colitis.

Nat Commun 2017 04 28;8:15069. Epub 2017 Apr 28.

Institute for Molecular Medicine, University Medical Center of the Johannes Gutenberg, University of Mainz, Obere Zahlbarer Str 67, 55131 Mainz, Germany.

Bcl-3 is an atypical NF-κB family member that regulates NF-κB-dependent gene expression in effector T cells, but a cell-intrinsic function in regulatory T (Treg) cells and colitis is not clear. Here we show that Bcl-3 expression levels in colonic T cells correlate with disease manifestation in patients with inflammatory bowel disease. Mice with T-cell-specific overexpression of Bcl-3 develop severe colitis that can be attributed to defective Treg cell development and function, leading to the infiltration of immune cells such as pro-inflammatory γδT cells, but not αβ T cells. In Treg cells, Bcl-3 associates directly with NF-κB p50 to inhibit DNA binding of p50/p50 and p50/p65 NF-κB dimers, thereby regulating NF-κB-mediated gene expression. This study thus reveals intrinsic functions of Bcl-3 in Treg cells, identifies Bcl-3 as a potential prognostic marker for colitis and illustrates the mechanism by which Bcl-3 regulates NF-κB activity in Tregs to prevent colitis.
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http://dx.doi.org/10.1038/ncomms15069DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5414353PMC
April 2017

TGF-β inhibitor Smad7 regulates dendritic cell-induced autoimmunity.

Proc Natl Acad Sci U S A 2017 02 6;114(8):E1480-E1489. Epub 2017 Feb 6.

Institute for Molecular Medicine, University Medical Center of the Johannes Gutenberg University Mainz, 55131 Mainz, Germany;

TGF-β is an anti-inflammatory cytokine whose signaling is negatively controlled by Smad7. Previously, we established a role for Smad7 in the generation of autoreactive T cells; however, the function of Smad7 in dendritic cells (DCs) remains elusive. Here, we demonstrate that DC-specific Smad7 deficiency resulted in elevated expression of the transcription factors Batf3 and IRF8, leading to increased frequencies of CD8CD103 DCs in the spleen. Furthermore, Smad7-deficient DCs expressed higher levels of indoleamine 2,3-dioxygenase (IDO), an enzyme associated with tolerance induction. Mice devoid of Smad7 specifically in DCs are resistant to the development of experimental autoimmune encephalomyelitis (EAE) as a result of an increase of protective regulatory T cells (Tregs) and reduction of encephalitogenic effector T cells in the central nervous system. In agreement, inhibition of IDO activity or depletion of Tregs restored disease susceptibility. Intriguingly, when Smad7-deficient DCs also lacked the IFN-γ receptor, the mice regained susceptibility to EAE, demonstrating that IFN-γ signaling in DCs mediates their tolerogenic function. Our data indicate that Smad7 expression governs splenic DC subset differentiation and is critical for the promotion of their efficient function in immunity.
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http://dx.doi.org/10.1073/pnas.1615065114DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5338403PMC
February 2017

EBI2 Is Highly Expressed in Multiple Sclerosis Lesions and Promotes Early CNS Migration of Encephalitogenic CD4 T Cells.

Cell Rep 2017 01;18(5):1270-1284

Institute for Molecular Medicine, University Medical Center of the Johannes Gutenberg-University Mainz, 55131 Mainz, Germany. Electronic address:

Arrival of encephalitogenic T cells at inflammatory foci represents a critical step in development of experimental autoimmune encephalomyelitis (EAE), the animal model for multiple sclerosis. EBI2 and its ligand, 7α,25-OHC, direct immune cell localization in secondary lymphoid organs. CH25H and CYP7B1 hydroxylate cholesterol to 7α,25-OHC. During EAE, we found increased expression of CH25H by microglia and CYP7B1 by CNS-infiltrating immune cells elevating the ligand concentration in the CNS. Two critical pro-inflammatory cytokines, interleukin-23 (IL-23) and interleukin-1 beta (IL-1β), maintained expression of EBI2 in differentiating Th17 cells. In line with this, EBI2 enhanced early migration of encephalitogenic T cells into the CNS in a transfer EAE model. Nonetheless, EBI2 was dispensable in active EAE. Human Th17 cells do also express EBI2, and EBI2 expressing cells are abundant within multiple sclerosis (MS) white matter lesions. These findings implicate EBI2 as a mediator of CNS autoimmunity and describe mechanistically its contribution to the migration of autoreactive T cells into inflamed organs.
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http://dx.doi.org/10.1016/j.celrep.2017.01.020DOI Listing
January 2017

IL-1 signaling is critical for expansion but not generation of autoreactive GM-CSF+ Th17 cells.

EMBO J 2017 01 8;36(1):102-115. Epub 2016 Nov 8.

Institute for Molecular Medicine, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany

Interleukin-1 (IL-1) is implicated in numerous pathologies, including multiple sclerosis and its animal model experimental autoimmune encephalomyelitis (EAE). However, the exact mechanism by which IL-1 is involved in the generation of pathogenic T cells and in disease development remains largely unknown. We found that following EAE induction, pertussis toxin administration leads to IL-1 receptor type 1 (IL-1R1)-dependent IL-1β expression by myeloid cells in the draining lymph nodes. This myeloid-derived IL-1β did not vitally contribute to the generation and plasticity of Th17 cells, but rather promoted the expansion of a GM-CSF Th17 cell subset, thereby enhancing its encephalitogenic potential. Lack of expansion of GM-CSF-producing Th17 cells led to ameliorated disease in mice deficient for IL-1R1 specifically in T cells. Importantly, pathogenicity of IL-1R1-deficient T cells was fully restored by IL-23 polarization and expansion in vitro Therefore, our data demonstrate that IL-1 functions as a mitogenic mediator of encephalitogenic Th17 cells rather than qualitative inducer of their generation.
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http://dx.doi.org/10.15252/embj.201694615DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5210124PMC
January 2017

Generation of a Novel T Cell Specific Interleukin-1 Receptor Type 1 Conditional Knock Out Mouse Reveals Intrinsic Defects in Survival, Expansion and Cytokine Production of CD4 T Cells.

PLoS One 2016 23;11(8):e0161505. Epub 2016 Aug 23.

Institute for Molecular Medicine, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany.

Interleukin-1 (IL-1) plays a crucial role in numerous inflammatory diseases via action on its only known signaling IL-1 receptor type 1 (IL-1R1). To investigate the role of IL-1 signaling in selected cell types, we generated a new mouse strain in which exon 5 of the Il1r1 gene is flanked by loxP sites. Crossing of these mice with CD4-Cre transgenic mice resulted in IL-1R1 loss of function specifically in T cells. These mice, termed IL-1R1ΔT, displayed normal development under steady state conditions. Importantly, isolated CD4 positive T cells retained their capacity to differentiate toward Th1 or Th17 cell lineages in vitro, and strongly proliferated in cultures supplemented with either anti-CD3/CD28 or Concanavalin A, but, as predicted, were completely unresponsive to IL-1β administration. Furthermore, IL-1R1ΔT mice were protected from gut inflammation in the anti-CD3 treatment model, due to dramatically reduced frequencies and absolute numbers of IL-17A and interferon (IFN)-γ producing cells. Taken together, our data shows the necessity of intact IL-1 signaling for survival and expansion of CD4 T cells that were developed in an otherwise IL-1 sufficient environment.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0161505PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4995027PMC
July 2017

Characterization of a conditional interleukin-1 receptor 1 mouse mutant using the Cre/LoxP system.

Eur J Immunol 2016 Apr 18;46(4):912-8. Epub 2016 Jan 18.

Faculty of Life Sciences, University of Manchester, Manchester, UK.

IL-1 is a key cytokine known to drive chronic inflammation and to regulate many physiological, immunological, and neuroimmunological responses via actions on diverse cell types of the body. To determine the mechanisms of IL-1 actions as part of the inflammatory response in vivo, we generated a conditional IL-1 receptor 1 (IL-1R1) mouse mutant using the Cre/LoxP system (IL-1R1(fl/fl) ). In the mutant generated, exon 5, which encodes part of the extracellular-binding region of the receptor, is flanked by LoxP sites, thereby inactivating the two previously described functional IL-1R1 gene transcripts after Cre-mediated recombination. Using keratin 14-Cre driver mice, new IL-1R1 deficient (-/-) mice were subsequently generated, in which all signaling IL-1 receptor isoforms are deleted ubiquitously. Furthermore, using vav-iCre driver mice, we deleted IL-1 receptor isoforms in the hematopoietic system. In these mice, we show that both the IL-17 and IL-22 cytokine response is reduced, when mice are challenged by the helminth Trichuris muris. We are currently crossing IL-1R1(fl/fl) mice with different Cre-expressing mice in order to study mechanisms of acute and chronic inflammatory diseases.
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http://dx.doi.org/10.1002/eji.201546075DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4982085PMC
April 2016

Isolation of Central Nervous System (CNS) Infiltrating Cells.

Methods Mol Biol 2016 ;1304:73-9

Institute for Molecular Medicine, University Medical Center of the Johannes Gutenberg-University of Mainz, Obere Zahlbacher Str. 67, 55131, Mainz, Germany,

Leukocyte infiltration of the central nervous system (CNS) occurs under certain pathogenic conditions and most often results in severe disorders. Therefore, the isolation and analysis of such infiltrating cell populations is necessary for elucidating the underlying pathogenic mechanisms. Here we describe a simple and straightforward protocol for cell isolation from the inflamed CNS, which combines mechanical dissociation and enzymatic degradation of the tissue. Additionally, purification by Percoll gradient centrifugation provides a great yield of the infiltrating material. The isolated cells can be further used for downstream applications such as cell sorting, cellular or molecular analysis.
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http://dx.doi.org/10.1007/7651_2014_114DOI Listing
May 2016