Publications about IL-1RAcP

Publication

[Function of the interleukin-1 gene system in immunomodulation, apoptosis and proliferation in the male gonad].

Journal: Postepy Higieny i Medycyny Doswiadczalnej

April/9/2006

Abstract

Spermatogenesis is a phenomenon where two main processes proliferation and apoptosis, meet. Slight changes in their activities could lead to different pathologies, such as fertility disorder (excessive apoptosis) or testicular cancer (overproliferation). The IL-1 gene family includes genes which play important roles in both these processes and consists of IL-1?, IL-1ss, IL-18, the IL-1 receptor antagonist (IL-1RA), two IL-1 receptors (IL-1RI, IL-1RII), the IL-18 receptor (IL-18R?), and the receptor-associated proteins - IL-1RAcP and IL-18Rss. Caspase-1 (ICE - interleukin-1 converting enzyme), directly connected with apoptosis and responsible for the cleavage of IL-1b and IL-18, is also a member of the IL-1 family. The system of the numerous IL-1 receptors and their signal transduction involving protein cascades provokes a range of gene expressions necessary for the initiation and maintenance of inflammatory reaction. In the testis, IL-1 is constitutively expressed, where it creates a unique microenvironment for diploid gametogenic cell conversion into specialized haploid spermatozoa. It may also be an element of the physiological protection from autoimmune attack by host testicular antigens and a part of immune privilege. This review is to summarize the knowledge of the local control of spermatogenesis and immunomodulation in the male gonad. As infertility is one of the main problems of industrialized countries, study of the pathophysiology of the male genital tract appears essential in future clinical practice.

Authors

Natalia Rozwadowska; Dorota Fiszer; Maciej Kurpisz

Publication

LAR-RPTP Clustering Is Modulated by Competitive Binding between Synaptic Adhesion Partners and Heparan Sulfate.

Download PDF

Journal: Frontiers in Molecular Neuroscience

November/1/2017

Abstract

The leukocyte common antigen-related receptor protein tyrosine phosphatases (LAR-RPTPs) are cellular receptors of heparan sulfate (HS) and chondroitin sulfate (CS) proteoglycans that direct axonal growth and neuronal regeneration. LAR-RPTPs are also synaptic adhesion molecules that form trans-synaptic adhesion complexes by binding to various postsynaptic adhesion ligands, such as Slit- and Trk-like family of proteins (Slitrks), IL-1 receptor accessory protein-like 1 (IL1RAPL1), interleukin-1 receptor accessory protein (IL-1RAcP) and neurotrophin receptor tyrosine kinase C (TrkC), to regulate synaptogenesis. Here, we determined the crystal structure of the human LAR-RPTP/IL1RAPL1 complex and found that lateral interactions between neighboring LAR-RPTP/IL1RAPL1 complexes in crystal lattices are critical for the higher-order assembly and synaptogenic activity of these complexes. Moreover, we found that LAR-RPTP binding to the postsynaptic adhesion ligands, Slitrk3, IL1RAPL1 and IL-1RAcP, but not TrkC, induces reciprocal higher-order clustering of trans-synaptic adhesion complexes. Although LAR-RPTP clustering was induced by either HS or postsynaptic adhesion ligands, the dominant binding of HS to the LAR-RPTP was capable of dismantling pre-established LAR-RPTP-mediated trans-synaptic adhesion complexes. These findings collectively suggest that LAR-RPTP clustering for synaptogenesis is modulated by a complex synapse-organizing protein network.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5645493/bin/fnmol-10-00327-g0001.jpg

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5645493/bin/fnmol-10-00327-g0002.jpg

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5645493/bin/fnmol-10-00327-g0003.jpg

Authors

Seoung Youn Won; Cha Yeon Kim; Doyoun Kim; Jaewon Ko; Ji Won Um; Sung Bae Lee+5 authors

Publication

The Delicate Balance between the Good and the Bad IL-1 Proinflammatory Effects in Endometriosis.

Journal: Current Medicinal Chemistry

August/20/2018

Abstract

BACKGROUND

Endometriosis is an inflammatory gynaecological disease with an associated chronic inflammation. Interleukin(IL)-1 is one of the most important immune and proinflammatory factors, produced mainly by monocytes and macrophages. Studies indicate the role of the cytokine from IL-1 family in endometrium-related disorders, particularly in endometriosis.

METHODS

The information about the impact of cytokine from IL-1 cytokine family on the pathogenesis and development of endometriosis was obtained with an electronic literature search based on the PubMed and Medline databases, spanning the period of January 1950 to July 2017 and includes associated references in the published studies.

RESULTS

The impairment of the IL-1 family cytokine-network may lead to changes in the activation of immune system in the peritoneal cavity of women with endometriosis. The aberrant ectopic endometrial cell properties of adhesion, implantation and proliferation may be the result of a reduced suppressive capacity controlling the IL-1. The imbalance between IL-1α, pro-IL-1β, mature IL-1β and sIL-1R2 and sIL-1RAcP in the peritoneal fluid and serum of women with endometriosis may be linked to the ability of transforming an acute inflammation into a chronic one. Despite the fact that peritoneal macrophages secrete more antiinflammatory IL-1Ra and less proinflammatory IL-1 in the peritoneal cavity in affected women, the inflammation still develops.

CONCLUSIONS

This observation clearly suggested a significant inadequacy in the specific regulatory mechanisms of IL-1 activity at the peritoneal cavity level. The imbalance between all studied cytokines in endometriosis may escalate peritoneal inflammation and, in consequence, develop endometriosis.

Authors

Justyna Sikora; Simone Ferrero; Aleksandra Mielczarek-Palacz; Zdzislawa Kondera-Anasz

Publication

Characterization and Validation of Arg286 Residue of IL-1RAcP as a Potential Drug Target for Osteoarthritis

Download PDF

Journal: Frontiers in Chemistry

February/21/2021

Abstract

Osteoarthritis (OA) is the most common form of arthritis and the fastest growing cause of chronic disability in the world. Formation of the ternary IL-1β /IL-1R1/IL-1RAcP protein complex and its downstream signaling has been implicated in osteoarthritis pathology. Current OA therapeutic approaches target either the cytokine IL-1β or the primary receptor IL-1RI but do not exploit the potential of the secondary receptor IL-1RAcP. Our previous work implicated the Arg286 residue of IL-1RAcP as a key mediator of complex formation. Molecular modeling confirmed Arg286 as a high-energy mediator of the ternary IL-1β complex architecture and interaction network. Anti-IL-1RAcP monoclonal antibodies (mAb) targeting the Arg286 residue were created and were shown to effectively reduce the influx of inflammatory cells to damaged joints in a mouse model of osteoarthritis. Inhibitory peptides based on the native sequence of IL-1RAcP were prepared and examined for efficacy at disrupting the complex formation. The most potent peptide inhibitor had an IC50 value of 304 pM in a pull-down model of complex formation, and reduced IL-1β signaling in a cell model by 90% at 2 μM. Overall, therapies that target the Arg286 region surface of IL-1RAcP, and disrupt subsequent interactions with subunits, have the potential to serve as next generation treatments for osteoarthritis.

Keywords: molecular dynamics; molecular modeling; peptide; protein painting; targeted inhibitors.

https://www.ncbi.nlm.nih.gov/pmc/articles/instance/7886681/bin/fchem-08-601477-g0001.jpg

IL-1β three-way complex formation with IL-1R1 and IL-1RAcP is required for inflammatory signaling,...

https://www.ncbi.nlm.nih.gov/pmc/articles/instance/7886681/bin/fchem-08-601477-g0002.jpg

Classical and quantum mechanics calculations show that Arg286 of IL-1RAcP is the highest energy...

https://www.ncbi.nlm.nih.gov/pmc/articles/instance/7886681/bin/fchem-08-601477-g0003.jpg

7B8D7 monoclonal antibody forms a stable complex with IL-1RAcP and targets Arg286. (A) 7B8D7 monoclonal...

Authors

Angela Dailing; Kelsey Mitchell; Ngoc Vuong; Kyung Lee; Reva Joshi; Virginia Espina+6 authors

Publication

Association of IL33 and IL1RAP Polymorphisms With Acute Anterior Uveitis.

Journal: Current Molecular Medicine

March/18/2018

Abstract

BACKGROUND

AAU (acute anterior uveitis) is the most common entity of uveitis characterized by acute vision loss and violent sore eyes. IL-33 and IL-1RacP have been found to play crucial roles in the innate immune system.

OBJECTIVE

In the present study, we investigated the association of IL33 and IL1RAP genes with AAU.

METHODS

A total of 549 AAU patients and 1080 unrelated healthy controls were recruited for this study. Ten single nucleotide polymorphisms (SNPs) were genotyped using Sequenom Mass ARRAY technology.

RESULTS

Our findings demonstrated that IL1RAP-rs3773978 significantly associated with AAU and could serve as a genetic risk marker in Chinese AAU patients. A significantly increased frequency of the A allele and AA homozygosity of IL1RAP-rs3773978 was observed in AAU patients compared with that in controls (p=0.001, pc=0.01, OR=1.282, 95% CI 1.106 to 1.487; p=0.0003, pc=0.003, OR=1.647, 95% CI 1.255 to 2.163, respectively). Further stratification analyses showed that the genetic correlation may differ depending on HLA-B27 status, AS (ankylosing spondylitis) status, attack times and laterality status.

CONCLUSIONS

Our findings provide new insights that enhance the current knowledge of uveitis genetics by demonstrating the specific functional roles of ILIL-1 family genes in uveitis.

Authors

X-F Huang; W Chi; D Lin; M-L Dai; Y-L Wang; Y-M Yang+2 authors

Related with

Authors(8)

Publication

Dual role of interleukin-33 in tumors

Journal: Journal of Central South University

March/7/2021

Abstract

Interleukin-33 (IL-33) is a new member of the IL-1 cytokine family which plays roles in the nucleus as a nuclear factor and is released by damaged or necrotic cells to act as a cytokine. It can be released via damaged or necrotic cells and functions as a cytokine. The released IL-33 activates the downstream NF-κB and MAPKs signaling pathways through the isomers of the specific receptor ST2 and the interleukin-1 receptor accessory protein (IL-1RAcP), resulting in danger signals and the activated multiple immune responses. IL-33 is abnormally expressed in various tumors and involves in tumorigenesis, development, and metastasis. Moreover, IL-33 can play both pro-tumor and anti-tumor roles in the same type of tumor.

白细胞介素-33(interleukin-33，IL-33)是IL-1家族的一位新成员，其不仅可以在细胞核内作为核因子发挥作用，也可以被损伤或坏死的细胞释放到细胞外作为细胞因子发挥作用。被释放的IL-33通过由特异性受体肿瘤发生抑制子2(suppression of tumorigenicity 2，ST2)及IL-1受体辅助蛋白(interleukin 1 receptor auxiliary protein，IL-1RAcP)组成的异构体激活下游的NF-κB和MAPKs信号通路，进一步激活多种免疫反应。IL-33在多种肿瘤(如肺癌、乳腺癌、结直肠癌等)中异常表达，参与肿瘤的发生、发展和转移，甚至在同一类肿瘤中同时发挥促肿瘤和抗肿瘤的双重作用。.

Keywords: interleukin-33; suppression of tumorigenicity 2; tumor; tumor microenvironment.

Authors

Qianqian Liu; Di Lu; Jiahua Hu; Junchao Liang; Huoying Chen

Publication

Mendelian randomization study of interleukin (IL)-1 family and lung cancer

Journal: BioImpacts

September/2/2021

Abstract

The role of interleukin (IL)-1 family members/receptors in lung cancer remains uncertain due to the susceptibility of observed associations to confounding. We appraised the association of IL-1 family members/receptors with lung cancer and its subtypes [lung adenocarcinoma (LUAD) and squamous cell lung cancer (LUSC)] using two-sample Mendelian randomization. This study found that no IL-1 family members/receptors were significantly associated with lung cancer and its subtypes risk after correction for multiple testing. However, suggestive total effects of increased risk were noted for genetically predicted IL-1Racp with lung cancer (P = 0.006), IL-1α with LUAD (P = 0.027), and IL-1Racp with LUSC (P = 0.008). Suggestive direct effects were also noted for IL-1β, IL-1Ra, IL-36γ with lung cancer, IL-1α/β, IL-1Ra with LUAD, and IL-1β, IL-18BP with LUSC, after adjusting for genetically predicted effects of other IL-1 family members/receptors. Taken together, our findings suggest that interventions decreasing IL-1Racp might protect against lung cancer, perhaps via IL-1α/β or IL-1Ra.

Authors

Zhao Yang; C Schooling; Man Kwok

Related with

References(51)Diseases(2)Anatomy(1)

Publication

Molecular Basis of Selective Cytokine Signaling Inhibition by Antibodies Targeting a Shared Receptor

Download PDF

Journal: Frontiers in Immunology

January/9/2022

Abstract

Interleukin-1 (IL-1) family cytokines are potent mediators of inflammation, acting to coordinate local and systemic immune responses to a wide range of stimuli. Aberrant signaling by IL-1 family cytokine members, however, is linked to myriad inflammatory syndromes, autoimmune conditions and cancers. As such, blocking the inflammatory signals inherent to IL-1 family signaling is an established and expanding therapeutic strategy. While several FDA-approved IL-1 inhibitors exist, including an Fc fusion protein, a neutralizing antibody, and an antagonist cytokine, none specifically targets the co-receptor IL-1 receptor accessory protein (IL-1RAcP). Most IL-1 family cytokines form productive signaling complexes by binding first to their cognate receptors - IL-1RI for IL-1α and IL-1β; ST2 for IL-33; and IL-36R for IL-36α, IL-36β and IL-36γ - after which they recruit the shared secondary receptor IL-1RAcP to form a ternary cytokine/receptor/co-receptor complex. Recently, IL-1RAcP was identified as a biomarker for both AML and CML. IL-1RAcP has also been implicated in tumor progression in solid tumors and an anti-IL1RAP antibody (nadunolimab, CAN04) is in phase II clinical studies in pancreatic cancer and non-small cell lung cancer (<a href="http://clinicaltrials.gov/show/NCT03267316" title="See in ClinicalTrials.gov">NCT03267316</a>). As IL-1RAcP is common to all of the abovementioned IL-1 family cytokines, targeting this co-receptor raises the possibility of selective signaling inhibition for different IL-1 family cytokines. Indeed, previous studies of IL-1β and IL-33 signaling complexes have revealed that these cytokines employ distinct mechanisms of IL-1RAcP recruitment even though their overall cytokine/receptor/co-receptor complexes are structurally similar. Here, using functional, biophysical, and structural analyses, we show that antibodies specific for IL-1RAcP can differentially block signaling by IL-1 family cytokines depending on the distinct IL-1RAcP epitopes that they engage. Our results indicate that targeting a shared cytokine receptor is a viable therapeutic strategy for selective cytokine signaling inhibition.

Keywords: IL-1; IL-1RAcp; IL-33; antibody; cytokine; shared receptor; signaling.

Authors

James Fields; Kyle Kihn; Gabriel Birkedal; Erik Klontz; Kjell Sjöström; Sebastian Günther+6 authors

Related with

Diseases(3)Chemicals(3)

Publication

IL-1, IL-18, and IL-33 families of cytokines.

Journal: Immunological Reviews

June/16/2009

Abstract

CONCLUSIONS

The interleukin-1 (IL-1), IL-18, and IL-33 families of cytokines are related by mechanism of origin, receptor structure, and signal transduction pathways utilized. All three cytokines are synthesized as precursor molecules and cleaved by the enzyme caspase-1 before or during release from the cell. The NALP-3 inflammasome is of crucial importance in generating active caspase-1. The IL-1 family contains two agonists, IL-1alpha and IL-1beta, a specific inhibitor, IL-1 receptor antagonist (IL-1Ra), and two receptors, the biologically active type IL-1R and inactive type II IL-1R. Both IL-1RI and IL-33R utilize the same interacting accessory protein (IL-1RAcP). The balance between IL-1 and IL-1Ra is important in preventing disease in various organs, and excess production of IL-1 has been implicated in many human diseases. The IL-18 family also contains a specific inhibitor, the IL-18-binding protein (IL-18BP), which binds IL-18 in the fluid phase. The IL-18 receptor is similar to the IL-1 receptor complex, including a single ligand-binding chain and a different interacting accessory protein. IL-18 provides an important link between the innate and adaptive immune responses. Newly described IL-33 binds to the orphan IL-1 family receptor T1/ST2 and stimulates T-helper 2 responses as well as mast cells.

Authors

William P Arend; Gaby Palmer; Cem Gabay

Publication

IL-1 receptor accessory protein and ST2 comprise the IL-33 receptor complex.

Journal: Journal of Immunology

October/2/2007

Abstract

IL-33 (IL-1F11) is a recently described member of the IL-1 family of cytokines that stimulates the generation of cells, cytokines, and Igs characteristic of a type 2 immune response. IL-33 mediates signal transduction through ST2, a receptor expressed on Th2 and mast cells. In this study, we demonstrate that IL-33 and ST2 form a complex with IL-1R accessory protein (IL-1RAcP), a signaling receptor subunit that is also a member of the IL-1R complex. Additionally, IL-1RAcP is required for IL-33-induced in vivo effects, and IL-33-mediated signal transduction can be inhibited by dominant-negative IL-1RAcP. The implications of this shared usage of IL-1RAcP by IL-1(alpha and beta) and IL-33 are discussed.

Authors

Alissa A Chackerian; Elizabeth R Oldham; Erin E Murphy; Jochen Schmitz; Stefan Pflanz; Robert A Kastelein

Publication

Role of IL-33 in inflammation and disease.

Download PDF

Journal: Journal of Inflammation

November/9/2011

Abstract

Interleukin (IL)-33 is a new member of the IL-1 superfamily of cytokines that is expressed by mainly stromal cells, such as epithelial and endothelial cells, and its expression is upregulated following pro-inflammatory stimulation. IL-33 can function both as a traditional cytokine and as a nuclear factor regulating gene transcription. It is thought to function as an 'alarmin' released following cell necrosis to alerting the immune system to tissue damage or stress. It mediates its biological effects via interaction with the receptors ST2 (IL-1RL1) and IL-1 receptor accessory protein (IL-1RAcP), both of which are widely expressed, particularly by innate immune cells and T helper 2 (Th2) cells. IL-33 strongly induces Th2 cytokine production from these cells and can promote the pathogenesis of Th2-related disease such as asthma, atopic dermatitis and anaphylaxis. However, IL-33 has shown various protective effects in cardiovascular diseases such as atherosclerosis, obesity, type 2 diabetes and cardiac remodeling. Thus, the effects of IL-33 are either pro- or anti-inflammatory depending on the disease and the model. In this review the role of IL-33 in the inflammation of several disease pathologies will be discussed, with particular emphasis on recent advances.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3175149/bin/1476-9255-8-22-1.jpg

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3175149/bin/1476-9255-8-22-2.jpg

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3175149/bin/1476-9255-8-22-3.jpg

Authors

Ashley M Miller

Publication

Opposing activities of two novel members of the IL-1 ligand family regulate skin inflammation.

Download PDF

Journal: Journal of Experimental Medicine

December/13/2007

Abstract

The interleukin (IL)-1 family members IL-1alpha, -1beta, and -18 are potent inflammatory cytokines whose activities are dependent on heterodimeric receptors of the IL-1R superfamily, and which are regulated by soluble antagonists. Recently, several new IL-1 family members have been identified. To determine the role of one of these family members in the skin, transgenic mice expressing IL1F6 in basal keratinocytes were generated. IL1F6 transgenic mice exhibit skin abnormalities that are dependent on IL-1Rrp2 and IL-1RAcP, which are two members of the IL-1R family. The skin phenotype is characterized by acanthosis, hyperkeratosis, the presence of a mixed inflammatory cell infiltrate, and increased cytokine and chemokine expression. Strikingly, the combination of the IL-1F6 transgene with an IL1F5 deficiency results in exacerbation of the skin phenotype, demonstrating that IL-1F5 has antagonistic activity in vivo. Skin from IL1F6 transgenic, IL1F5(-/-) pups contains intracorneal and intraepithelial pustules, nucleated corneocytes, and dilated superficial dermal blood vessels. Additionally, expression of IL1RL2, -1F5, and -1F6 is increased in human psoriatic skin. In summary, dysregulated expression of novel agonistic and antagonistic IL-1 family member ligands can promote cutaneous inflammation, revealing potential novel targets for the treatment of inflammatory skin disorders.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2118475/bin/jem2042603f01.jpg

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2118475/bin/jem2042603f02.jpg

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2118475/bin/jem2042603f03.jpg

Authors

Hal Blumberg; Huyen Dinh; Esther S Trueblood; James Pretorius; David Kugler; Ning Weng+6 authors

Publication

Tollip, a new component of the IL-1RI pathway, links IRAK to the IL-1 receptor.

Journal: Nature Cell Biology

July/16/2000

Abstract

Interleukin-1 (IL-1) is a proinflammatory cytokine that elicits its pleiotropic effects through activation of the transcription factors NF-kappaB and AP-1. Binding of IL-1 to its receptor results in rapid assembly of a membrane-proximal signalling complex that consists of two different receptor chains (IL-1Rs), IL-1RI and IL-1RAcP, the adaptor protein MyD88, the serine/threonine kinase IRAK and a new protein, which we have named Tollip. Here we show that, before IL-1beta treatment, Tollip is present in a complex with IRAK, and that recruitment of Tollip-IRAK complexes to the activated receptor complex occurs through association of Tollip with IL-1RAcP. Co-recruited MyD88 then triggers IRAK autophosphorylation, which in turn leads to rapid dissociation of IRAK from Tollip (and IL-1Rs). As overexpression of Tollip results in impaired NF-kappaB activation, we conclude that Tollip is an important constituent of the IL-1R signalling pathway.

Authors

K Burns; J Clatworthy; L Martin; F Martinon; C Plumpton; B Maschera+4 authors

Publication

Interleukin (IL)-1F6, IL-1F8, and IL-1F9 signal through IL-1Rrp2 and IL-1RAcP to activate the pathway leading to NF-kappaB and MAPKs.

Journal: Journal of Biological Chemistry

May/10/2004

Abstract

Interleukin 1 (IL-1) plays a prominent role in immune and inflammatory reactions. Our understanding of the IL-1 family has recently expanded to include six novel members named IL-1F5 to IL-1F10. Recently, it was reported that IL-1F9 activated NF-kappaB through the orphan receptor IL-1 receptor (IL-1R)-related protein 2 (IL-1Rrp2) in Jurkat cells (Debets, R., Timans, J. C., Homey, B., Zurawski, S., Sana, T. R., Lo, S., Wagner, J., Edwards, G., Clifford, T., Menon, S., Bazan, J. F., and Kastelein, R. A. (2001) J. Immunol. 167, 1440-1446). In this study, we demonstrate that IL-1F6 and IL-1F8, in addition to IL-1F9, activate the pathway leading to NF-kappaB in an IL-1Rrp2-dependent manner in Jurkat cells as well as in multiple other human and mouse cell lines. Activation of the pathway leading to NF-kappaB by IL-1F6 and IL-1F8 follows a similar time course to activation by IL-1beta, suggesting that signaling by the novel family members occurs through a direct mechanism. In a mammary epithelial cell line, NCI/ADR-RES, which naturally expresses IL-1Rrp2, all three cytokines signal without further receptor transfection. IL-1Rrp2 antibodies block activation of the pathway leading to NF-kappaB by IL-1F6, IL-1F8, and IL-1F9 in both Jurkat and NCI/ADR-RES cells. In NCI/ADR-RES cells, the three IL-1 homologs activated the MAPKs, JNK and ERK1/2, and activated downstream targets as well, including an IL-8 promoter reporter and the secretion of IL-6. We also provide evidence that IL-1RAcP, in addition to IL-1Rrp2, is required for signaling by all three cytokines. Antibodies directed against IL-1RAcP and transfection of cytoplasmically deleted IL-1RAcP both blocked activation of the pathway leading to NF-kappaB by the three cytokines. We conclude that IL-1F6, IL-1F8, and IL-1F9 signal through IL-1Rrp2 and IL-1RAcP.

Authors

Jennifer E Towne; Kirsten E Garka; Blair R Renshaw; G Duke Virca; John E Sims

Publication

IL-1 receptor accessory protein is essential for IL-33-induced activation of T lymphocytes and mast cells.

Download PDF

Journal: Proceedings of the National Academy of Sciences of the United States of America

January/1/2008

Abstract

Lack of the IL-1 receptor accessory protein (IL-1RAcP) abrogates responses to IL-33 and IL-1 in the mouse thymoma clone EL-4 D6/76 cells. Reconstitution with full-length IL-1RAcP is sufficient to restore responsiveness to IL-33 and IL-1. IL-33 activates IL-1 receptor-associated kinase-1, cJun-N-terminal kinase, and the NF-kappaB pathway in an IL-1RAcP-dependent manner and results in IL-2 release. IL-33 is able to induce the release of proinflammatory cytokines in bone marrow-derived (BMD) mast cells, indicating that IL-33 may have a proinflammatory potential like its relatives IL-1 and IL-18, in addition to its Th2-skewing properties in the adaptive response described previously. Blocking of murine IL-1RAcP with the neutralizing antibody 4C5 inhibits response of mouse thymoma cells and BMD mast cells to IL-33. The interaction of either membrane-bound or soluble forms of IL-1RAcP and IL-33Ralpha-chain depends on the presence of IL-33, as demonstrated by coimmunoprecipitation assays. These data demonstrate that IL-1RAcP is indispensable for IL-33 signaling. Furthermore, they suggest that IL-1RAcP is used by more than one alpha-chain of the IL-1 receptor family and thus may resemble a common beta-chain of that family.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2141833/bin/zpq0460783330001.jpg

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2141833/bin/zpq0460783330002.jpg

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2141833/bin/zpq0460783330003.jpg

Authors

Shafaqat Ali; Michael Huber; Christian Kollewe; Stephan C Bischoff; Werner Falk; Michael U Martin

Publication

IL-36R ligands are potent regulators of dendritic and T cells.

Journal: Blood

January/26/2012

Abstract

IL-36α (IL-1F6), IL-36β (IL-1F8), and IL-36γ (IL-1F9) are members of the IL-1 family of cytokines. These cytokines bind to IL-36R (IL-1Rrp2) and IL-1RAcP, activating similar intracellular signals as IL-1, whereas IL-36Ra (IL-1F5) acts as an IL-36R antagonist (IL-36Ra). In this study, we show that both murine bone marrow-derived dendritic cells (BMDCs) and CD4(+) T lymphocytes constitutively express IL-36R and respond to IL-36α, IL-36β, and IL-36γ. IL-36 induced the production of proinflammatory cytokines, including IL-12, IL-1β, IL-6, TNF-α, and IL-23 by BMDCs with a more potent stimulatory effect than that of other IL-1 cytokines. In addition, IL-36β enhanced the expression of CD80, CD86, and MHC class II by BMDCs. IL-36 also induced the production of IFN-γ, IL-4, and IL-17 by CD4(+) T cells and cultured splenocytes. These stimulatory effects were antagonized by IL-36Ra when used in 100- to 1000-fold molar excess. The immunization of mice with IL-36β significantly and specifically promoted Th1 responses. Our data thus indicate a critical role of IL-36R ligands in the interface between innate and adaptive immunity, leading to the stimulation of T helper responses.

Authors

Solenne Vigne; Gaby Palmer; Céline Lamacchia; Praxedis Martin; Dominique Talabot-Ayer; Emiliana Rodriguez+5 authors

Publication

Interleukin-33 overexpression is associated with liver fibrosis in mice and humans.

Download PDF

Journal: Journal of Cellular and Molecular Medicine

November/22/2010

Abstract

Interleukin-33 (IL-33), the most recently identified member of the IL-1 family, induces synthesis of T Helper 2 (Th2)-type cytokines via its heterodimeric ST2/IL-1RAcP receptor. Th2-type cytokines play an important role in fibrosis; thus, we investigated the role of IL-33 in liver fibrosis. IL-33, ST2 and IL-1RAcP gene expression was analysed in mouse and human normal (n= 6) and fibrotic livers (n= 28), and in human hepatocellular carcinoma (HCC; n= 22), using real-time PCR. IL-33 protein was detected in normal and fibrotic liver sections and in isolated liver cells using Western blotting and immunolocalization approaches. Our results showed that IL-33 and ST2 mRNA was overproduced in mouse and human fibrotic livers, but not in human HCC. IL-33 expression correlated with ST2 expression and also with collagen expression in fibrotic livers. The major sources of IL-33 in normal liver from both mice and human beings are the liver sinusoidal endothelial cells and, in fibrotic liver, the activated hepatic stellate cells (HSC). Moreover, IL-33 expression was increased in cultured HSC when stimulated by pro-inflammatory cytokines. In conclusion, IL-33 is strongly associated with fibrosis in chronic liver injury and activated HSC are a source of IL-33.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3829034/bin/jcmm0014-1726-f1.jpg

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3829034/bin/jcmm0014-1726-f2.jpg

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3829034/bin/jcmm0014-1726-f3.jpg

Authors

Pierrick Marvie; Mariette Lisbonne; Annie L'helgoualc'h; Michel Rauch; Bruno Turlin; Laurence Preisser+5 authors

Publication

Cloning of a novel receptor subunit, AcPL, required for interleukin-18 signaling.

Journal: Journal of Biological Chemistry

December/9/1998

Abstract

We have identified a novel member of the interleukin-1 (IL-1) receptor family, which we have termed AcPL. In transient transfection assays, we were unable to demonstrate a role for AcPL in IL-1-induced activation of NFkappaB. Interleukin-18 (interferon-gamma-inducing factor) is another member of the IL-1 family of cytokines, and it has recently been shown that IL-18 has a weak affinity for IL-1R-rp1. We examined whether AcPL might function alone or in concert with IL-1R-rp1 to mediate IL-18 signaling. We found that both IL-1R-rp1 and AcPL expression were required for induction of NFkappaB activity and for activation of c-Jun N-terminal kinase in response to IL-18. Furthermore, a dominant negative version of AcPL specifically inhibited IL-18 signaling. In vitro immunoprecipitation assays demonstrated that AcPL alone was unable to bind IL-18 with any appreciable affinity. We propose that although IL-1R-rp1 binds the cytokine, IL-1R-rp1 and AcPL proteins are both required for IL-18 signaling, analogous to the requirement for both IL-1R and IL-1RAcP in IL-1-mediated responses.

Authors

T L Born; E Thomassen; T A Bird; J E Sims

Publication

Interleukin-36 (IL-36) ligands require processing for full agonist (IL-36α, IL-36β, and IL-36γ) or antagonist (IL-36Ra) activity.

Download PDF

Journal: Journal of Biological Chemistry

February/20/2012

Abstract

IL-36α, IL-36β, and IL-36γ (formerly IL-1F6, IL-1F8, and IL-1F9) are IL-1 family members that signal through the IL-1 receptor family members IL-1Rrp2 (IL-1RL2) and IL-1RAcP. IL-36Ra (formerly IL-1F5) has been reported to antagonize IL-36γ. However, our previous attempts to demonstrate IL-36Ra antagonism were unsuccessful. Here, we demonstrate that IL-36Ra antagonist activity is dependent upon removal of its N-terminal methionine. IL-36Ra starting at Val-2 is fully active and capable of inhibiting not only IL-36γ but also IL-36α and IL-36β. Val-2 of IL-36Ra lies 9 amino acids N-terminal to an A-X-Asp motif conserved in all IL-1 family members. In further experiments, we show that truncation of IL-36α, IL-36β, and IL-36γ to this same point increased their specific activity by ∼10(3)-10(4)-fold (from EC(50) 1 μg/ml to EC(50) 1 ng/ml). Inhibition of truncated IL-36β activity required ∼10(2)-10(3)-fold excess IL-36Ra, similar to the ratio required for IL-1Ra to inhibit IL-1β. Chimeric receptor experiments demonstrated that the extracellular (but not cytoplasmic) domain of IL-1Rrp2 or IL-1R1 is required for inhibition by their respective natural antagonists. IL-36Ra bound to IL-1Rrp2, and pretreatment of IL-1Rrp2-expressing cells with IL-36Ra prevented IL-36β-mediated co-immunoprecipitation of IL-1Rrp2 with IL-1RAcP. Taken together, these results suggest that the mechanism of IL-36Ra antagonism is analogous to that of IL-1Ra, such that IL-36Ra binds to IL-1Rrp2 and prevents IL-1RAcP recruitment and the formation of a functional signaling complex. In addition, truncation of IL-36α, IL-36β, and IL-36γ dramatically enhances their activity, suggesting that post-translational processing is required for full activity.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3234937/bin/zbc0511187430001.jpg

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3234937/bin/zbc0511187430002.jpg

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3234937/bin/zbc0511187430003.jpg

Authors

Jennifer E Towne; Blair R Renshaw; Jason Douangpanya; Brian P Lipsky; Min Shen; Christopher A Gabel; John E Sims

Publication

IL-33 and ST2 in atopic dermatitis: expression profiles and modulation by triggering factors.

Journal: The Journal of investigative dermatology

June/17/2012

Abstract

In the acute phase of atopic dermatitis (AD), T-helper type 2 (Th2) cytokines characterize the inflammatory response in the skin. IL-33 is a new tissue-derived cytokine, which is mainly expressed by cells of barrier tissues, and is known to activate Th2 lymphocytes, mast cells, and eosinophils. IL-33 signals through a receptor complex consisting of IL-33-specific receptor ST2 and a co-receptor IL-1RAcP. As IL-33 is known to promote Th2-type immunity, we examined expression profiles of IL-33 and its receptor components in human AD skin, in the murine model of AD, and in various cell models. We found increased expression of IL-33 and ST2 in AD skin after allergen or staphylococcal enterotoxin B (SEB) exposure, as well as in the skin of 22-week-old filaggrin-deficient mice. In addition, skin fibroblasts, HaCaT keratinocytes, primary macrophages, and HUVEC endothelial cells efficiently produced IL-33 in response to the combined stimulation of tumor necrosis factor-α and IFN-γ, which was further enhanced by a mimetic of double-stranded RNA. Finally, the increased expression of IL-33 and ST2 caused by irritant, allergen, or SEB challenge was suppressed by topical tacrolimus treatment. These results suggest an important role for IL-33-ST2 interaction in AD and highlight the fact that bacterial and viral infections may increase the production of IL-33.

Authors

Terhi Savinko; Sampsa Matikainen; Ulpu Saarialho-Kere; Maili Lehto; Guoying Wang; Sari Lehtimäki+5 authors

Publication

SIGIRR inhibits interleukin-1 receptor- and toll-like receptor 4-mediated signaling through different mechanisms.

Journal: Journal of Biological Chemistry

August/15/2005

Abstract

The Toll-interleukin-1 receptor (TIR) domain-containing orphan receptor SIGIRR (single immunoglobulin interleukin-1 receptor-related protein) acts as a negative regulator of interleukin (IL)-1 and lipopolysaccharide (LPS) signaling. Endogenous SIGIRR transiently interacted with IL-1 receptor and the receptor-proximal signaling components (MyD88, IRAK, and tumor necrosis factor receptor-associated factor 6) upon IL-1 stimulation, indicating that SIGIRR interacts with the IL-1 receptor complex in a ligand-dependent manner. Similar interaction was also observed between SIGIRR and Toll-like receptor 4 receptor complex upon LPS stimulation. To identify the domains of SIGIRR required for its interaction with the Toll-like receptor 4 and IL-1 receptor complexes, several SIGIRR deletion mutants were generated, including DeltaN (lacking the extracellular immunoglobulin (Ig) domain with deletion of amino acids 1-119), DeltaC (lacking the C-terminal domain with deletion of amino acids 313-410), and DeltaTIR (lacking the TIR domain with deletion of amino acids 161-313). Whereas both the extracellular Ig domain and the intracellular TIR domains are important for SIGIRR to inhibit IL-1 signaling, only the TIR domain is necessary for SIGIRR to inhibit LPS signaling. The extracellular Ig domain exerts its inhibitory role in IL-1 signaling by interfering with the heterodimerization of IL-1 receptor and IL-1RAcP, whereas the intracellular TIR domain inhibits both IL-1 and LPS signaling by attenuating the recruitment of receptor-proximal signaling components to the receptor. These results indicate that SIGIRR inhibits IL-1 and LPS signaling pathways through differential mechanisms.

Authors

Jinzhong Qin; Youcun Qian; Jianhong Yao; Cui Grace; Xiaoxia Li

Publication

Structural insights into the assembly and activation of IL-1β with its receptors.

Journal: Nature Immunology

November/2/2010

Abstract

Interleukin 1β (IL-1β) is a key orchestrator of inflammation and host defense that exerts its effects through IL-1 receptor type I (IL-1RI) and IL-1 receptor accessory protein (IL-1RAcP). How IL-1RAcP is recruited by IL-1β-IL-1RI to form the signaling-competent complex remains elusive. Here we present the crystal structure of IL-1β bound to IL-1 receptor type II (IL-1RII) and IL-1RAcP. IL-1β-IL-1RII generated a composite binding surface to recruit IL-1RAcP. Biochemical analysis demonstrated that IL-1β-IL-1RI and IL-1β-IL-1RII interacted similarly with IL-1RAcP. It also showed the importance of two loops of IL-1 receptor antagonist (IL-1Ra) in determining its antagonism. Our results provide a structural basis for assembly and activation of the IL-1 receptor and offer a general cytokine-receptor architecture that governs the IL-1 family of cytokines.

Authors

Dongli Wang; Senyan Zhang; Liang Li; Xi Liu; Kunrong Mei; Xinquan Wang

Publication

Endogenous IL-33 enhances Th2 cytokine production and T-cell responses during allergic airway inflammation.

Journal: International Immunology

January/2/2012

Abstract

IL-33 is an IL-1-related cytokine which has been implicated in T(h)2-associated biology and allergic diseases in humans and mice. IL-33 stimulates T(h)2 cells, mast cells, eosinophils, basophils, iNKT cells and circulating CD34(+) stem cells to proliferate and produce pro-allergic cytokines such as IL-5 and IL-13. IL-33 mediates its cytokine effects through a receptor consisting of ST2 and IL-1RAcP. Whereas IL-1RAcP is ubiquitously expressed, ST2 expression is cell-type restricted and determines responsiveness to IL-33. Studies employing ST2-deficient mice have reported variable results on the role of this receptor, and consequently IL-33, with regards to allergic lung inflammation. In this study, we demonstrate that IL-33 is important for allergic lung inflammation. Intra-nasal administration of IL-33 triggered an immediate allergic response in the airways, and more importantly, we show that endogenous IL-33 contributes to airway inflammation and peripheral antigen-specific responses in ovalbumin-induced acute allergic lung inflammation using IL-33-deficient mice. Our results suggest that IL-33 is sufficient and required for severe allergic inflammation in the lung and support the concept of IL-33 as a therapeutic target in allergic lung inflammation.

Authors

Jennifer Louten; Andrew L Rankin; Ying Li; Erin E Murphy; Maribel Beaumont; Christina Moon+4 authors

Publication

Production and functions of IL-33 in the central nervous system.

Journal: Brain Research

February/13/2012

Abstract

Interleukin-33 (IL-33) is a novel multifunctional IL-1 family cytokine. IL-33 signals via a heterodimer composed of IL-1 receptor-related protein ST2 and IL-1 receptor accessory protein (IL-1RAcP). IL-33 has been shown to activate T helper 2 cells (Th2), mast cells and basophils to produce a variety of Th2 cytokines and mediate allergic-type immune responses. Recent studies have revealed that glial cells are induced to express IL-33 mRNA and protein. However, the functions of IL-33 and its producing cells in the central nervous system (CNS) are still uncertain. In this study, we investigated the expression and function of IL-33 in the CNS. IL-33 is produced by endothelial cells and astrocytes but not by microglia or neurons. The IL-33 receptors are expressed mainly in microglia and astrocytes. IL-33 dose-dependently induces the proliferation of microglia and enhances the production of pro-inflammatory cytokines, such as IL-1β and TNFα, as well as the anti-inflammatory cytokine IL-10. It also enhances chemokines and nitric oxide production and phagocytosis by microglia. Thus, IL-33 produced in the CNS activates microglia and may function as a pro-inflammatory mediator in the pathophysiology of the CNS.

Authors

Satoko Yasuoka; Jun Kawanokuchi; Bijay Parajuli; Shijie Jin; Yukiko Doi; Mariko Noda+4 authors

Publication

The IL-33/ST2 pathway--A new therapeutic target in cardiovascular disease.

Journal: Pharmacology and Therapeutics

November/6/2011

Abstract

Numerous pro-inflammatory cytokines have been implicated in the pathogenesis of several cardiovascular diseases. Interleukin (IL)-33 is a new member of the IL-1 family of cytokines that promotes Th2 type immune responses by signaling through the ST2L and IL-1RAcP dimeric receptor complex. Furthermore, the biological effects of IL-33 are limited by a soluble decoy form of ST2 (sST2). Recent studies indicate a protective role for IL-33 and ST2L in atherosclerosis, obesity and cardiac remodeling. The present review summarizes currently available data showing the role for IL-33 and its receptor ST2L within cardiovascular disease, and the potential use of sST2 as a predictive cardiovascular biomarker.

Authors

Ashley M Miller; Foo Y Liew

Publication

The interleukin-1 receptor accessory protein (IL-1RAcP) is essential for IL-1-induced activation of interleukin-1 receptor-associated kinase (IRAK) and stress-activated protein kinases (SAP kinases).

Journal: Journal of Biological Chemistry

April/17/1997

Abstract

Interleukin-1 (IL-1) is a central mediator of the immune system involved in acute and chronic inflammatory responses. Although the sequences of two types of IL-1 receptors are known, the exact molecular events resulting in signal transduction and coupling to downstream signaling elements remain unclear. The recently cloned IL-1 receptor accessory protein (IL-1RAcP) has been suggested as a co-receptor molecule for IL-1RI, supported by the observation that its expression correlates to IL-1 responsiveness. We transfected the EL-4 subline D6/76 with IL-1RAcP cDNA. This cell line is an IL-1 non-responder expressing IL-1RI but lacking constitutive IL-1RAcP expression. The expression of IL-1RAcP in EL-4 D6/76 was sufficient to restore IL-1-induced activation of interleukin-1 receptor-associated kinase and of stress-activated protein kinases, translocation of the transcription factors NFkappaB and IL-1 NF to the nucleus, and induction of IL-2 mRNA synthesis. These results proved that IL-1RAcP is an indispensible molecule in the IL-1 receptor signal transduction complex, necessary to link events on the plasma membrane level to downstream signaling pathways, allowing IL-1-dependent activation of transcription factors and gene expression.

Authors

H Wesche; C Korherr; M Kracht; W Falk; K Resch; M U Martin

Publication

Structure of IL-33 and its interaction with the ST2 and IL-1RAcP receptors--insight into heterotrimeric IL-1 signaling complexes.

Download PDF

Journal: Structure

January/24/2010

Abstract

Members of the interleukin-1 (IL-1) family of cytokines play major roles in host defense and immune system regulation in infectious and inflammatory diseases. IL-1 cytokines trigger a biological response in effector cells by assembling a heterotrimeric signaling complex with two IL-1 receptor chains, a high-affinity primary receptor and a low-affinity coreceptor. To gain insights into the signaling mechanism of the novel IL-1-like cytokine IL-33, we first solved its solution structure and then performed a detailed biochemical and structural characterization of the interaction between IL-33, its primary receptor ST2, and the coreceptor IL-1RAcP. Using nuclear magnetic resonance data, we obtained a model of the IL-33/ST2 complex in solution that is validated by small-angle X-ray scattering (SAXS) data and is similar to the IL-1beta/IL-1R1 complex. We extended our SAXS analysis to the IL-33/ST2/IL-1RAcP and IL-1beta/IL-1R1/IL-1RAcP complexes and propose a general model of the molecular architecture of IL-1 ternary signaling complexes.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2766095/bin/nihms147387f1.jpg

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2766095/bin/nihms147387f2.jpg

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2766095/bin/nihms147387f3.jpg

Authors

Andreas Lingel; Thomas M Weiss; Marc Niebuhr; Borlan Pan; Brent A Appleton; Christian Wiesmann+2 authors

Publication

Structural insights into the interaction of IL-33 with its receptors.

Download PDF

Journal: Proceedings of the National Academy of Sciences of the United States of America

December/9/2013

Abstract

Interleukin (IL)-33 is an important member of the IL-1 family that has pleiotropic activities in innate and adaptive immune responses in host defense and disease. It signals through its ligand-binding primary receptor ST2 and IL-1 receptor accessory protein (IL-1RAcP), both of which are members of the IL-1 receptor family. To clarify the interaction of IL-33 with its receptors, we determined the crystal structure of IL-33 in complex with the ectodomain of ST2 at a resolution of 3.27 Å. Coupled with structure-based mutagenesis and binding assay, the structural results define the molecular mechanism by which ST2 specifically recognizes IL-33. Structural comparison with other ligand-receptor complexes in the IL-1 family indicates that surface-charge complementarity is critical in determining ligand-binding specificity of IL-1 primary receptors. Combined crystallography and small-angle X-ray-scattering studies reveal that ST2 possesses hinge flexibility between the D3 domain and D1D2 module, whereas IL-1RAcP exhibits a rigid conformation in the unbound state in solution. The molecular flexibility of ST2 provides structural insights into domain-level conformational change of IL-1 primary receptors upon ligand binding, and the rigidity of IL-1RAcP explains its inability to bind ligands directly. The solution architecture of IL-33-ST2-IL-1RAcP complex from small-angle X-ray-scattering analysis resembles IL-1β-IL-1RII-IL-1RAcP and IL-1β-IL-1RI-IL-1RAcP crystal structures. The collective results confer IL-33 structure-function relationships, supporting and extending a general model for ligand-receptor assembly and activation in the IL-1 family.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3773798/bin/pnas.1308651110fig01.jpg

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3773798/bin/pnas.1308651110fig02.jpg

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3773798/bin/pnas.1308651110fig03.jpg

Authors

Xi Liu; Michal Hammel; Yanfeng He; John A Tainer; U-Ser Jeng; Linqi Zhang+2 authors

Publication

MyD88-dependent and -independent signaling by IL-1 in neurons probed by bifunctional Toll/IL-1 receptor domain/BB-loop mimetics.

Download PDF

Journal: Proceedings of the National Academy of Sciences of the United States of America

June/12/2006

Abstract

Interleukin (IL)-1beta is a pluripotent proinflammatory cytokine that signals through the type-I IL-1 receptor (IL-1RI), a member of the Toll-like receptor family. In hypothalamic neurons, binding of IL-1beta to IL-1RI mediates transcription-dependent changes that depend on the recruitment of the cytosolic adaptor protein myeloid differentiation primary-response protein 88 (MyD88) to the IL-1RI/IL-1 receptor accessory protein (IL-1RAcP) complex through homomeric Toll/IL-1 receptor (TIR)-TIR interactions. Through design and synthesis of bifunctional TIR mimetics that disrupt the interaction of MyD88 with the IL-1RI/IL-1RAcP complex, we analyzed the involvement of MyD88 in the signaling of IL-1beta in anterior hypothalamic neurons. We show here that IL-1beta-mediated activation of the protein tyrosine kinase Src depended on a MyD88 interaction with the IL-1RI/IL-1RAcP complex. The activation of the protein kinase Akt/PKB depended on the recruitment of the p85 subunit of PI3K to IL-1RI and independent of MyD88 association with the IL-1RI/IL-1RAcP complex. These bifunctional TIR-TIR mimetics represent a class of low-molecular-weight compounds with both an antiinflammatory and neuroprotective potential. These compounds have the potential to inhibit the MyD88-dependent proinflammatory actions of IL-1beta, while permitting the potential neuronal survival supporting actions mediated by the MyD88-independent activation of the protein kinase Akt.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1413805/bin/zpq0060612270001.jpg

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1413805/bin/zpq0060612270002.jpg

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1413805/bin/zpq0060612270003.jpg

Authors

Christopher N Davis; Enrique Mann; M Margarita Behrens; Svetlana Gaidarova; Mitra Rebek; Julius Rebek; Tamas Bartfai

Publication

Reversal of autocrine and paracrine effects of interleukin 1 (IL-1) in human arthritis by type II IL-1 decoy receptor. Potential for pharmacological intervention.

Journal: Journal of Biological Chemistry

January/31/2001

Abstract

Interleukin 1 (IL-1), produced by both synovial cells and chondrocytes, plays a pivotal role in the pathogenesis of cartilage destruction in osteoarthritis (OA). We examined the specific expression and function of IL-1 receptor family-related genes in human joint tissues. Gene array analysis of human normal and OA-affected cartilage showed mRNA expression of IL-1 receptor accessory protein (IL-1RAcp) and IL-1 type I receptor (IL-1RI), but not IL-1 antagonist (IL-1ra) and IL-1 type II decoy receptor (IL-1RII). Similarly, human synovial and epithelial cells showed an absence of IL-1RII mRNA. Functional genomic analyses showed that soluble (s) IL-1RII, at picomolar concentrations, but not soluble TNF receptor:Fc, significantly inhibited IL-1beta-induced nitric oxide (NO) and/or prostaglandin E(2) production in chondrocytes, synovial and epithelial cells. In OA-affected cartilage, the IC(50) for inhibition of NO production by sIL-1RII was 2 log orders lower than that for sIL-1RI. Human chondrocytes that overexpressed IL-1RII were resistant to IL-1-induced IL-1beta mRNA accumulation and inhibition of proteoglycan synthesis. In osteoarthritis, deficient expression by chondrocytes of innate regulators or antagonists of IL-1 such as IL-1ra and IL-1RII (soluble or membrane form) may allow the catabolic effects of IL-1 to proceed unopposed. The sensitivity of IL-1 action to inhibition by sIL-1RII has therapeutic implications that could be directed toward correcting this unfavorable tissue(s) dependent imbalance.

Authors

M G Attur; M Dave; C Cipolletta; P Kang; M B Goldring; I R Patel+2 authors

Publication

Intracellular trafficking of interleukin-1 receptor I requires Tollip.

Journal: Current Biology

January/23/2007

Abstract

Interleukin-1 receptor (IL-1RI) is a master regulator of inflammation and innate immunity. When triggered by IL-1beta, IL-1RI aggregates with IL-1R-associated protein (IL-1RAcP) and forms a membrane proximal signalosome that potently activates downstream signaling cascades. IL-1beta also rapidly triggers endocytosis of IL-1RI. Although internalization of IL-1RI significantly impacts signaling, very little is known about trafficking of IL-1RI and therefore about precisely how endocytosis modulates the overall cellular response to IL-1beta. Upon internalization, activated receptors are often sorted through endosomes and delivered to lysosomes for degradation. This is a highly regulated process that requires ubiquitination of cargo proteins as well as protein-sorting complexes that specifically recognize ubiquitinated cargo. Here, we show that IL-1beta induces ubiquitination of IL-1RI and that via these attached ubiquitin groups, IL-1RI interacts with the ubiquitin-binding protein Tollip. By using an assay to follow trafficking of IL-1RI from the cell surface to late endosomes and lysosomes, we demonstrate that Tollip is required for sorting of IL-1RI at late endosomes. In Tollip-deficient cells and cells expressing only mutated Tollip (incapable of binding IL-1RI and ubiquitin), IL-1RI accumulates on late endosomes and is not efficiently degraded. Furthermore, we show that IL-1RI interacts with Tom1, an ubiquitin-, clathrin-, and Tollip-binding protein, and that Tom1 knockdown also results in the accumulation of IL-1RI at late endosomes. Our findings suggest that Tollip functions as an endosomal adaptor linking IL-1RI, via Tom1, to the endosomal degradation machinery.

Authors

Brian Brissoni; Laetitia Agostini; Michel Kropf; Fabio Martinon; Valentin Swoboda; Saskia Lippens+9 authors

Publication

Interleukin-1 receptor accessory protein organizes neuronal synaptogenesis as a cell adhesion molecule.

Journal: Journal of Neuroscience

April/15/2012

Abstract

Interleukin-1 receptor accessory protein (IL-1RAcP) is the essential component of receptor complexes mediating immune responses to interleukin-1 family cytokines. IL-1RAcP in the brain exists in two isoforms, IL-1RAcP and IL-1RAcPb, differing only in the C-terminal region. Here, we found robust synaptogenic activities of IL-1RAcP in cultured cortical neurons. Knockdown of IL-1RAcP isoforms in cultured cortical neurons suppressed synapse formation as indicated by decreases of active zone protein Bassoon puncta and dendritic protrusions. IL-1RAcP recovered the accumulation of presynaptic Bassoon puncta, while IL-1RAcPb rescued both Bassoon puncta and dendritic protrusions. Consistently, the expression of IL-1RAcP in cortical neurons enhances the accumulation of Bassoon puncta and that of IL-1RAcPb stimulated both Bassoon puncta accumulation and spinogenesis. IL-1RAcP interacted with protein tyrosine phosphatase (PTP) δ through the extracellular domain. Mini-exon peptides in the Ig-like domains of PTPδ splice variants were critical for their efficient binding to IL-1RAcP. The synaptogenic activities of IL-1RAcP isoforms were diminished in cortical neurons from PTPδ knock-out mice. Correspondingly, PTPδ required IL-1RAcPb to induce postsynaptic differentiation. Thus, IL-1RAcPb bidirectionally regulated synapse formation of cortical neurons. Furthermore, the spine densities of cortical and hippocampal pyramidal neurons were reduced in IL-1RAcP knock-out mice lacking both isoforms. These results suggest that IL-1RAcP isoforms function as trans-synaptic cell adhesion molecules in the brain and organize synapse formation. Thus, IL-1RAcP represents an interesting molecular link between immune systems and synapse formation in the brain.

Authors

Tomoyuki Yoshida; Tomoko Shiroshima; Sung-Jin Lee; Misato Yasumura; Takeshi Uemura; Xigui Chen+2 authors