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1.
Front Immunol ; 14: 1254697, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37942327

RESUMO

Introduction: CXCL17 is a mucosally secreted protein, and the most recently identified human chemokine, an assignment based on protein fold prediction and chemotactic activity for leukocytes. However, these credentials have been the subject of much recent discussion and no experimental evidence has been presented regarding the definitive structure of CXCL17. In this study, we evaluated the structural and chemoattractant credentials of CXCL17 to better characterize this molecule, and gain deeper insights into its functional role as a glycosaminoglycan (GAG) binding protein. Methods: In the absence of structural information, in silico modeling techniques assessed the likelihood of CXCL17 adopting a chemokine fold. Recombinant CXCL17 was synthesized in mammalian and prokaryotic systems. Modified Boyden chamber and real-time chemotaxis assays assessed the ability of CXCL17 to promote chemotaxis of murine splenocytes, human neutrophils, and CXCR1 transfectants. The efficacy of CXCL17 binding to GAGs was quantified with solid-phase assays and bio-layer interferometry techniques. Results: All modeling efforts failed to support classification of CXCL17 as a chemokine based on its predicted conformation. Recombinant CXCL17 was observed to dimerize as a function of concentration, a characteristic of several chemokines. Contrary to a previous report, CXCL17 was not chemotactic for murine splenocytes, although it was a low-potency chemoattractant for human neutrophils at micromolar concentrations, several orders of magnitude higher than those required for CXCL8. As anticipated owing to its highly basic nature, CXCL17 bound to GAGs robustly, with key C-terminal motifs implicated in this process. While inactive via CXCR1, CXCL17 was found to inhibit CXCR1-mediated chemotaxis of transfectants to CXCL8 in a dose-dependent manner. Discussion: In summary, despite finding little evidence for chemokine-like structure and function, CXCL17 readily bound GAGs, and could modulate chemotactic responses to another chemokine in vitro. We postulate that such modulation is a consequence of superior GAG binding, and that C-terminal fragments of CXCL17 may serve as prototypic inhibitors of chemokine function.


Assuntos
Quimiocinas , Glicosaminoglicanos , Humanos , Animais , Camundongos , Glicosaminoglicanos/metabolismo , Quimiocinas/metabolismo , Quimiotaxia , Neutrófilos/metabolismo , Mamíferos/metabolismo , Quimiocinas CXC/metabolismo
2.
Biochim Biophys Acta Proteins Proteom ; 1871(6): 140946, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37562488

RESUMO

Annually, over 18 million disease cases and half a million deaths worldwide are estimated to be caused by Group A Streptococcus. ScpA (or C5a peptidase) is a well characterised member of the cell enveleope protease family, which possess a S8 subtilisin-like catalytic domain and a shared multi-domain architecture. ScpA cleaves complement factors C5a and C3a, impairing the function of these critical anaphylatoxins and disrupts complement-mediated innate immunity. Although the high resolution structure of ScpA is known, the details of how it recognises its substrate are only just emerging. Previous studies have identified a distant exosite on the 2nd fibronectin domain that plays an important role in recruitment via an interaction with the substrate core. Here, using a combination of solution NMR spectroscopy, mutagenesis with functional assays and computational approaches we identify a second exosite within the protease-associated (PA) domain. We propose a model in which the PA domain assists optimal delivery of the substrate's C terminus to the active site for cleavage.


Assuntos
Peptídeo Hidrolases , Streptococcus pyogenes , Imunidade Inata
3.
J Clin Med ; 9(10)2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-33081170

RESUMO

Immune checkpoint inhibitors (ICI) have revolutionised cancer therapy. However, they have been effective in only a small subset of patients and a principal mechanism underlying immune-refractoriness is a 'cold' tumour microenvironment, that is, lack of a T-cell-rich, spontaneously inflamed phenotype. As such, there is a demand to develop strategies to transform the tumour milieu of non-responsive patients to one supporting T-cell-based inflammation. The cyclic guanosine monophosphate-adenosine monophosphate synthase-stimulator of interferon genes (cGAS-STING) pathway is a fundamental regulator of innate immune sensing of cancer, with potential to enhance tumour rejection through the induction of a pro-inflammatory response dominated by Type I interferons. Recognition of these positive immune-modulatory properties has rapidly elevated the STING pathway as a putative target for immunotherapy, leading to a myriad of preclinical and clinical studies assessing natural and synthetic cyclic dinucleotides and non-nucleotidyl STING agonists. Despite pre-clinical evidence of efficacy, clinical translation has resulted into disappointingly modest efficacy. Poor pharmacokinetic and physiochemical properties of cyclic dinucleotides are key barriers to the development of STING agonists, most of which require intra-tumoral dosing. Development of systemically administered non-nucleotidyl STING agonists, or conjugation with liposomes, polymers and hydrogels may overcome pharmacokinetic limitations and improve drug delivery. In this review, we summarise the body of evidence supporting a synergistic role of STING agonists with currently approved ICI therapies and discuss whether, despite the numerous obstacles encountered to date, the clinical development of STING agonist as novel anti-cancer therapeutics may still hold the promise of broadening the reach of cancer immunotherapy.

4.
J Leukoc Biol ; 107(3): 455-466, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32052476

RESUMO

CCR4 is the sole receptor for the chemokines CCL22 and CCL17. Clinical studies of asthmatic airways have shown levels of both ligands and CCR4+ Th2 cells to be elevated, suggestive of a role in disease. Consequently, CCR4 has aroused much interest as a potential therapeutic target and an understanding of how its cell surface expression is regulated is highly desirable. To this end, receptor expression, receptor endocytosis, and chemotaxis were assessed using transfectants expressing CCR4, CCR4+ human T cell lines, and human Th2 cells polarized in vitro. CCL17 and CCL22 drove rapid endocytosis of CCR4 in a dose-dependent manner. Replenishment at the cell surface was slow and sensitive to cycloheximide, suggestive of de novo synthesis of CCR4. Constitutive CCR4 endocytosis was also observed, with the internalized CCR4 found to be significantly degraded over a 6-h incubation. Truncation of the CCR4 C-terminus by 40 amino acids had no effect on cell surface expression, but resulted in significant impairment of ligand-induced endocytosis. Consequently, migration to both CCL17 and CCL22 was significantly enhanced. In contrast, truncation of CCR4 did not impair constitutive endocytosis or degradation, suggesting the use of alternative receptor motifs in these processes. We conclude that CCR4 cell surface levels are tightly regulated, with a degradative fate for endocytosed receptor. We postulate that this strict control is desirable, given that Th2 cells recruited by CCR4 can induce the further expression of CCR4 ligands in a positive feedback loop, thereby enhancing allergic inflammation.


Assuntos
Inflamação/imunologia , Proteólise , Receptores CCR4/metabolismo , Células Th2/imunologia , Animais , Anticorpos/metabolismo , Células CHO , Membrana Celular/metabolismo , Quimiotaxia , Cricetinae , Cricetulus , Endocitose , Glicosilação , Humanos , Hipersensibilidade/imunologia , Hipersensibilidade/patologia , Ligantes , Camundongos , Transfecção
5.
Sci Immunol ; 4(36)2019 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-31175176

RESUMO

Group 2 innate lymphoid cells (ILC2s) are enriched in mucosal tissues (e.g., lung) and respond to epithelial cell-derived cytokines initiating type 2 inflammation. During inflammation, ILC2 numbers are increased in the lung. However, the mechanisms controlling ILC2 trafficking and motility within inflamed lungs remain unclear and are crucial for understanding ILC2 function in pulmonary immunity. Using several approaches, including lung intravital microscopy, we demonstrate that pulmonary ILC2s are highly dynamic, exhibit amoeboid-like movement, and aggregate in the lung peribronchial and perivascular spaces. They express distinct chemokine receptors, including CCR8, and actively home to CCL8 deposits located around the airway epithelium. Within lung tissue, ILC2s were particularly motile in extracellular matrix-enriched regions. We show that collagen-I drives ILC2 to markedly change their morphology by remodeling their actin cytoskeleton to promote environmental exploration critical for regulating eosinophilic inflammation. Our study provides previously unappreciated insights into ILC2 migratory patterns during inflammation and highlights the importance of environmental guidance cues in the lung in controlling ILC2 dynamics.


Assuntos
Pulmão/imunologia , Linfócitos/imunologia , Animais , Movimento Celular/efeitos dos fármacos , Colágeno/imunologia , Eosinófilos/imunologia , Matriz Extracelular/imunologia , Feminino , Fibronectinas/imunologia , Humanos , Imunidade Inata , Inflamação/imunologia , Interleucina-33/farmacologia , Linfócitos/efeitos dos fármacos , Camundongos Endogâmicos BALB C , Camundongos Transgênicos , Proteínas Recombinantes/farmacologia
6.
J Immunol ; 202(11): 3246-3255, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-31010851

RESUMO

To evade the immune system, the lethal human pathogen Streptococcus pyogenes produces SpyCEP, an enzyme that cleaves the C-terminal α-helix of CXCL8, resulting in markedly impaired recruitment of neutrophils to sites of invasive infection. The basis for chemokine inactivation by SpyCEP is, however, poorly understood, as the core domain of CXCL8 known to interact with CXCL8 receptors is unaffected by enzymatic cleavage. We examined the in vitro migration of human neutrophils and observed that their ability to efficiently navigate a CXCL8 gradient was compromised following CXCL8 cleavage by SpyCEP. SpyCEP-mediated cleavage of CXCL8 also impaired CXCL8-induced migration of transfectants expressing the human chemokine receptors CXCR1 or CXCR2. Despite possessing an intact N terminus and preserved disulfide bonds, SpyCEP-cleaved CXCL8 had impaired binding to both CXCR1 and CXCR2, pointing to a requirement for the C-terminal α-helix. SpyCEP-cleaved CXCL8 had similarly impaired binding to the glycosaminoglycan heparin. Enzymatic removal of neutrophil glycosaminoglycans was observed to ablate neutrophil navigation of a CXCL8 gradient, whereas navigation of an fMLF gradient remained largely intact. We conclude, therefore, that SpyCEP cleavage of CXCL8 results in chemokine inactivation because of a requirement for glycosaminoglycan binding in productive chemokine:receptor interactions. This may inform strategies to inhibit the activity of SpyCEP, but may also influence future approaches to inhibit unwanted chemokine-induced inflammation.


Assuntos
Glicosaminoglicanos/metabolismo , Heparina/metabolismo , Interleucina-8/metabolismo , Neutrófilos/imunologia , Peptídeo Hidrolases/metabolismo , Infecções Estreptocócicas/imunologia , Streptococcus pyogenes/fisiologia , Animais , Células Cultivadas , Humanos , Camundongos , Ligação Proteica , Engenharia de Proteínas , Receptores de Interleucina-8A/metabolismo , Receptores de Interleucina-8B/metabolismo
8.
J Innate Immun ; 10(5-6): 465-478, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30165356

RESUMO

Viruses use diverse molecular mechanisms to exploit and evade the immune response. Herpesviruses, in particular, encode functional chemokine and chemokine receptor homologs pirated from the host, as well as secreted chemokine-binding proteins with unique structures. Multiple functions have been described for herpesvirus chemokine components, including attraction of target cells, blockade of leukocyte migration, and modulation of gene expression and cell entry by the virus. Here we review current concepts about how human herpesvirus chemokines, chemokine receptors, and chemokine-binding proteins may be used to shape a proviral state in the host.


Assuntos
Infecções por Herpesviridae/imunologia , Herpesviridae/fisiologia , Leucócitos/imunologia , Animais , Movimento Celular , Quimiocinas/metabolismo , Interações Hospedeiro-Patógeno , Humanos , Evasão da Resposta Imune , Leucócitos/virologia , Receptores de Quimiocinas/metabolismo
9.
Sci Rep ; 8(1): 9466, 2018 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-29930254

RESUMO

Activated platelets release micromolar concentrations of the chemokine CXCL4/Platelet Factor-4. Deposition of CXCL4 onto the vascular endothelium is involved in atherosclerosis, facilitating monocyte arrest and recruitment by an as yet, unidentified receptor. Here, we demonstrate that CXCL4 drives chemotaxis of the monocytic cell line THP-1. Migration and intracellular calcium responses induced by CXCL4 were pertussis toxin-sensitive, implicating a GPCR in signal transduction. Cell treatment with chondroitinase ABC ablated migration, suggesting that cis presentation of CXCL4 by cell surface glycosaminoglycans to a GPCR is required. Although CXCR3 has been previously described as a CXCL4 receptor, THP-1 cells were unresponsive to CXCR3 ligands and CXCL4-induced migration was insensitive to a CXCR3 antagonist, suggesting that an alternative receptor is involved. Interrogating CC-class chemokine receptor transfectants, we unexpectedly found that CXCL4 could induce the migration of CCR1-expressing cells and also induce CCR1 endocytosis. Extending our findings to primary human monocytes, we observed that CXCL4 induced CCR1 endocytosis and could induce monocyte chemotaxis in a CCR1 antagonist-sensitive manner. Collectively, our data identify CCR1 as a previously elusive monocyte CXCL4 receptor and suggest that CCR1 may play a role in inflammation where the release of CXCL4 is implicated.


Assuntos
Quimiotaxia , Monócitos/metabolismo , Fator Plaquetário 4/metabolismo , Receptores CCR1/metabolismo , Cálcio/metabolismo , Linhagem Celular , Células Cultivadas , Condroitina ABC Liase/farmacologia , Endocitose , Humanos , Monócitos/efeitos dos fármacos , Monócitos/fisiologia , Toxina Pertussis/farmacologia , Fator Plaquetário 4/genética , Ligação Proteica
10.
J Immunol ; 201(2): 714-724, 2018 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-29875152

RESUMO

The chemokine CXCL17 is associated with the innate response in mucosal tissues but is poorly characterized. Similarly, the G protein-coupled receptor GPR35, expressed by monocytes and mast cells, has been implicated in the immune response, although its precise role is ill-defined. A recent manuscript reported that GPR35 was able to signal in response to CXCL17, which we set out to confirm in this study. GPR35 was readily expressed using transfection systems but failed to signal in response to CXCL17 in assays of ß-arrestin recruitment, inositol phosphate production, calcium flux, and receptor endocytosis. Similarly, in chemotaxis assays, GPR35 did not confirm sensitivity to a range of CXCL17 concentrations above that observed in the parental cell line. We subsequently employed a real time chemotaxis assay (TAXIScan) to investigate the migratory responses of human monocytes and the monocytic cell line THP-1 to a gradient of CXCL17. Freshly isolated human monocytes displayed no obvious migration to CXCL17. Resting THP-1 cells showed a trend toward directional migration along a CXCL17 gradient, which was significantly enhanced by overnight incubation with PGE2 However, pretreatment of PGE2-treated THP-1 cells with the well-characterized GPR35 antagonist ML145 did not significantly impair their migratory responses to CXCL17 gradient. CXCL17 was susceptible to cleavage with chymase, although this had little effect its ability to recruit THP-1 cells. We therefore conclude that GPR35 is unlikely to be a bona fide receptor for CXCL17 and that THP-1 cells express an as yet unidentified receptor for CXCL17.


Assuntos
Quimiocinas CXC/metabolismo , Monócitos/fisiologia , Receptores Acoplados a Proteínas G/metabolismo , Animais , Sinalização do Cálcio , Quimiocinas CXC/genética , Quimiotaxia , Endocitose , Humanos , Imunidade Inata , Camundongos , Receptores Acoplados a Proteínas G/genética , Transdução de Sinais , Células THP-1 , beta-Arrestinas/metabolismo
11.
Clin Exp Allergy ; 48(5): 490-492, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29701922
12.
Expert Opin Drug Discov ; 12(2): 159-168, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28010133

RESUMO

INTRODUCTION: By virtue of its specificity for chemokines induced in Th1-associated pathologies, CXCR3 has attracted considerable attention as a target for therapeutic intervention. Several pharmacologically distinct small molecules with in vitro and in vivo potency have been described in the literature, although to date, none have shown efficacy in clinical trials. Areas covered: In this article, the author outlines the rationale for targeting CXCR3 and discusses the potential pitfalls in targeting receptors in poorly understood areas of chemokine biology. Furthermore, they cover emerging therapeutic areas outside of the 'traditional' Th1 arena in which CXCR3 antagonists may ultimately bear fruit. Finally, they discuss the design of recently discovered small molecules targeting CXCR3. Expert opinion: CXCR3 and its ligands appear to play roles in a multitude of diverse diseases in humans. In vitro studies suggest that CXCR3 is inherently 'druggable' and that potent, efficacious small molecules targeting CXCR3 antagonists will find a clinical niche. However, the well-trodden path to failure of small molecule chemokine receptor antagonists in clinical trials suggests that a cautious approach should be undertaken. Ideally, unequivocal evidence elucidating the precise role of CXCR3 should be obtained before targeting the receptor in a particular disease cohort.


Assuntos
Desenho de Fármacos , Receptores CXCR3/antagonistas & inibidores , Células Th1/metabolismo , Animais , Humanos , Ligantes , Terapia de Alvo Molecular
13.
J Leukoc Biol ; 99(6): 901-9, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26701135

RESUMO

Chemokine receptors are typically promiscuous, binding more than one ligand, with the ligands themselves often expressed in different spatial localizations by multiple cell types. This is normally a tightly regulated process; however, in a variety of inflammatory disorders, dysregulation results in the excessive or inappropriate expression of chemokines that drives disease progression. Biased agonism, the phenomenon whereby different ligands of the same receptor are able to preferentially activate one signaling pathway over another, adds another level of complexity to an already complex system. In this minireview, we discuss the concept of biased agonism within the chemokine family and report that targeting single signaling axes downstream of chemokine receptors is not only achievable, but may well present novel opportunities to target chemokine receptors, allowing the fine tuning of receptor responses in the context of allergic inflammation and beyond.


Assuntos
Descoberta de Drogas , Receptores de Quimiocinas/agonistas , Animais , Humanos , Ligantes , Modelos Biológicos , Receptores CCR4/antagonistas & inibidores , Receptores CCR4/metabolismo , Receptores de Quimiocinas/metabolismo
14.
Immunity ; 43(5): 945-58, 2015 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-26588780

RESUMO

Epithelial cells orchestrate pulmonary homeostasis and pathogen defense and play a crucial role in the initiation of allergic immune responses. Maintaining the balance between homeostasis and inappropriate immune activation and associated pathology is particularly complex at mucosal sites that are exposed to billions of potentially antigenic particles daily. We demonstrated that epithelial cell-derived cytokine TGF-ß had a central role in the generation of the pulmonary immune response. Mice that specifically lacked epithelial cell-derived TGF-ß1 displayed a reduction in type 2 innate lymphoid cells (ILCs), resulting in suppression of interleukin-13 and hallmark features of the allergic response including airway hyperreactivity. ILCs in the airway lumen were primed to respond to TGF-ß by expressing the receptor TGF-ßRII and ILC chemoactivity was enhanced by TGF-ß. These data demonstrate that resident epithelial cells instruct immune cells, highlighting the central role of the local environmental niche in defining the nature and magnitude of immune reactions.


Assuntos
Células Epiteliais/imunologia , Imunidade Inata/imunologia , Pulmão/imunologia , Linfócitos/imunologia , Fator de Crescimento Transformador beta1/imunologia , Animais , Células Cultivadas , Interleucina-13/imunologia , Camundongos , Proteínas Serina-Treonina Quinases/imunologia , Receptor do Fator de Crescimento Transformador beta Tipo II , Receptores de Fatores de Crescimento Transformadores beta/imunologia , Hipersensibilidade Respiratória/imunologia
15.
Immunol Lett ; 168(2): 285-92, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26475400

RESUMO

Bisphenol A (BPA) is a widely used plasticizer, which came into focus because of its genotoxic and sensitizing potential. Besides its toxic properties, BPA is also well-known for its antioxidant chemical properties. This in vitro study investigated the interference of BPA with interferon-γ (IFN-γ)-induced tryptophan breakdown and neopterin production in human peripheral blood mononuclear cells (PBMC). The pro-inflammatory cytokine IFN-γ induces the conversion of the essential amino acid tryptophan into kynurenine via the enzyme indoleamine-2,3-dioxygenase (IDO-1). In parallel, GTP-cyclohydrolase produces neopterin, a marker of immune activation. A model system of phytohaemagglutinin (PHA)-stimulated PBMC was used to assess potential immunomodulatory properties of BPA. Treatment of cells with BPA [12.5-200µM] resulted in a significant and dose-dependent suppression of mitogen-induced tryptophan breakdown and neopterin formation along with a decrease of IFN-γ levels. Similar but less pronounced effects were observed in unstimulated cells. We postulate that the inhibitory effects of BPA on both T-cell activation and IDO-1 activity that we describe here may be critical for immune surveillance and is likely to influence T helper (Th) type 1/Th2 balance. Such immunosuppressive effects likely contribute to counteract inflammation. Further studies are required to address the in vivo relevance our in vitro findings.


Assuntos
Compostos Benzidrílicos/farmacologia , Leucócitos Mononucleares/efeitos dos fármacos , Fenóis/farmacologia , Células Th1/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Citocinas/imunologia , Citocinas/metabolismo , Relação Dose-Resposta a Droga , Ensaio de Imunoadsorção Enzimática , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/imunologia , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Mediadores da Inflamação/imunologia , Mediadores da Inflamação/metabolismo , Interferon gama/imunologia , Interferon gama/metabolismo , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , NF-kappa B/imunologia , NF-kappa B/metabolismo , Neopterina/imunologia , Neopterina/metabolismo , Fito-Hemaglutininas/farmacologia , Células Th1/imunologia , Células Th1/metabolismo , Triptofano/imunologia , Triptofano/metabolismo
16.
Proc Natl Acad Sci U S A ; 112(35): 11001-6, 2015 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-26283380

RESUMO

Whereas the importance of macrophages in chronic inflammatory diseases is well recognized, there is an increasing awareness that neutrophils may also play an important role. In addition to the well-documented heterogeneity of macrophage phenotypes and functions, neutrophils also show remarkable phenotypic diversity among tissues. Understanding the molecular pathways that control this heterogeneity should provide abundant scope for the generation of more specific and effective therapeutics. We have shown that the transcription factor IFN regulatory factor 5 (IRF5) polarizes macrophages toward an inflammatory phenotype. IRF5 is also expressed in other myeloid cells, including neutrophils, where it was linked to neutrophil function. In this study we explored the role of IRF5 in models of acute inflammation, including antigen-induced inflammatory arthritis and lung injury, both involving an extensive influx of neutrophils. Mice lacking IRF5 accumulate far fewer neutrophils at the site of inflammation due to the reduced levels of chemokines important for neutrophil recruitment, such as the chemokine (C-X-C motif) ligand 1. Furthermore we found that neutrophils express little IRF5 in the joints and that their migratory properties are not affected by the IRF5 deficiency. These studies extend prior ones suggesting that inhibiting IRF5 might be useful for chronic macrophage-induced inflammation and suggest that IRF5 blockade would ameliorate more acute forms of inflammation, including lung injury.


Assuntos
Inflamação/fisiopatologia , Fatores Reguladores de Interferon/fisiologia , Doença Aguda , Animais , Quimiocinas/fisiologia , Doença Crônica , Inflamação/patologia , Macrófagos/patologia , Camundongos , Membrana Sinovial/patologia
17.
J Exp Med ; 212(6): 845-53, 2015 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-25941255

RESUMO

The most studied biological role of type III interferons (IFNs) has so far been their antiviral activity, but their role in autoimmune and inflammatory diseases remains largely unexplored. Here, we show that treatment with IFN-λ2/IL-28A completely halts and reverses the development of collagen-induced arthritis (CIA) and discover cellular and molecular mechanisms of IL-28A antiinflammatory function. We demonstrate that treatment with IL-28A dramatically reduces numbers of proinflammatory IL-17-producing Th17 and γδ T cells in the joints and inguinal lymph nodes, without affecting T cell proliferative responses or levels of anticollagen antibodies. IL-28A exerts its antiinflammatory effect by restricting recruitment of IL-1b-expressing neutrophils, which are important for amplification of inflammation. We identify neutrophils as cells expressing high levels of IFN-λ receptor 1 (IFNLR1)-IL-28 receptor α (IL28RA) and targeted by IL-28A. Our data highlight neutrophils as contributors to the pathogenesis of autoimmune arthritis and present IFN-λs or agonists of IFNLR1-IL28RA as putative new therapeutics for neutrophil-driven inflammation.


Assuntos
Regulação da Expressão Gênica , Inflamação/metabolismo , Interleucina-1beta/metabolismo , Interleucinas/farmacologia , Animais , Artrite/metabolismo , Linfócitos T CD4-Positivos/citologia , Bovinos , Movimento Celular , Proliferação de Células , Galinhas , Colágeno/química , Citometria de Fluxo , Interleucina-17/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Neutrófilos/citologia , Neutrófilos/metabolismo , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo , Receptores de Citocinas/metabolismo , Linfócitos T/citologia
18.
Eur J Pharmacol ; 763(Pt B): 169-77, 2015 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-25981299

RESUMO

Since their early 1990s, the chemokine receptor family of G protein-coupled receptors (GPCRs) has been the source of much pharmacological endeavour. Best known for their key roles in recruiting leukocytes to sites of infection and inflammation, the receptors present themselves as plausible drug targets for therapeutic intervention. In this article, we will focus our attention upon CC Chemokine Receptor Four (CCR4) which has been implicated in diseases as diverse as allergic asthma and lymphoma. We will review the discovery of the receptors and their ligands, their perceived roles in disease and the successful targeting of CCR4 by both small molecule antagonists and monoclonal antibodies. We will also discuss future directions and strategies for drug discovery in this field.


Assuntos
Doença , Terapia de Alvo Molecular/métodos , Receptores CCR4/metabolismo , Animais , Humanos , Receptores CCR4/antagonistas & inibidores
19.
Br J Pharmacol ; 172(7): 1822-33, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25425280

RESUMO

BACKGROUND AND PURPOSE: The chemokine receptor CXCR3 is implicated in a variety of clinically important diseases, notably rheumatoid arthritis and atherosclerosis. Consequently, antagonists of CXCR3 are of therapeutic interest. In this study, we set out to characterize binding sites of the specific low MW CXCR3 antagonist VUF10085 and the broad spectrum antagonist TAK-779 which blocks CXCR3 along with CCR2 and CCR5. EXPERIMENTAL APPROACH: Molecular modelling of CXCR3, followed by virtual ligand docking, highlighted several CXCR3 residues likely to contact either antagonist, notably a conserved aspartate in helix 2 (Asp-112(2:63) ), which was postulated to interact with the quaternary nitrogen of TAK-779. Validation of modelling was carried out by site-directed mutagenesis of CXCR3, followed by assays of cell surface expression, ligand binding and receptor activation. KEY RESULTS: Mutation of Asn-132(3.33) , Phe-207 and Tyr-271(6.51) within CXCR3 severely impaired both ligand binding and chemotactic responses, suggesting that these residues are critical for maintenance of a functional CXCR3 conformation. Contrary to our hypothesis, mutation of Asp-112(2:63) had no observable effects on TAK-779 activity, but clearly decreased the antagonist potency of VUF 10085. Likewise, mutations of Phe-131(3.32) , Ile-279(6.59) and Tyr-308(7.43) were well tolerated and were critical for the antagonist activity of VUF 10085 but not for that of TAK-779. CONCLUSIONS AND IMPLICATIONS: This more detailed definition of a binding pocket within CXCR3 for low MW antagonists should facilitate the rational design of newer CXCR3 antagonists, with obvious clinical potential.


Assuntos
Acetamidas/farmacologia , Amidas/farmacologia , Antagonistas dos Receptores CCR5/farmacologia , Pirimidinonas/farmacologia , Compostos de Amônio Quaternário/farmacologia , Receptores CXCR3/antagonistas & inibidores , Receptores CXCR3/metabolismo , Animais , Sítios de Ligação , Linhagem Celular , Quimiotaxia , Camundongos , Modelos Moleculares , Mutagênese Sítio-Dirigida , Receptores CXCR3/química , Receptores CXCR3/genética
20.
Eur J Pharmacol ; 746: 363-7, 2015 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-25016087

RESUMO

Chemokines are a family of around 40 small proteins, which are secreted by a variety of cells, including structural cell types and leukocytes of the immune system. Chemokines bind to their specific 7-transmembrane G protein-coupled receptors (GPCRs) and induce a variety of downstream signals which notably modulate polymerization of the actin cytoskeleton and thus drive cellular motility. Excessive or inappropriate release of chemokines is observed in many inflammatory diseases and so there has been a great effort in industry to target chemokine receptors. The large family of GPCRs regulate many physiological cellular processes and they have proved to be highly amenable to pharmacological intervention with small chemicals. Consequently GPCRs make attractive targets for drug discovery and indeed a large number of successful current therapeutics are either agonists or antagonists of GPCRs. The apparent lack of success with chemokine receptors has been frustrating and in this paper we discuss potential reasons for previous failures and also why there is considerable cause for optimism.


Assuntos
Fármacos Anti-HIV/farmacologia , Anti-Inflamatórios não Esteroides/farmacologia , Drogas em Investigação/farmacologia , Fatores Imunológicos/farmacologia , Modelos Biológicos , Receptores de Quimiocinas/antagonistas & inibidores , Animais , Fármacos Anti-HIV/efeitos adversos , Fármacos Anti-HIV/uso terapêutico , Anti-Inflamatórios não Esteroides/efeitos adversos , Anti-Inflamatórios não Esteroides/uso terapêutico , Ensaios Clínicos como Assunto , Desenho de Fármacos , Descoberta de Drogas/tendências , Drogas em Investigação/efeitos adversos , Drogas em Investigação/uso terapêutico , Término Precoce de Ensaios Clínicos , Humanos , Fatores Imunológicos/efeitos adversos , Fatores Imunológicos/uso terapêutico , Terapia de Alvo Molecular/efeitos adversos , Receptores de Quimiocinas/metabolismo
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