Publications
137 results found
Pease JE, Sozzani S, 2024, Atypical chemoattractants and their receptors: A potential gateway to novel therapeutic strategies., Cytokine
Pearson M, Haslam C, Fosberry A, et al., 2023, Structure-activity studies of Streptococcus pyogenes enzyme SpyCEP reveal high affinity for CXCL8 in the SpyCEP C-terminal, Scientific Reports, Vol: 13, ISSN: 2045-2322
The Streptococcus pyogenes cell envelope protease (SpyCEP) is vital to streptococcal pathogenesis and disease progression. Despite its strong association with invasive disease, little is known about enzymatic function beyond the ELR+ CXC chemokine substrate range. As a serine protease, SpyCEP has a catalytic triad consisting of aspartate (D151), histidine (H279), and serine (S617) residues which are all thought to be mandatory for full activity. We utilised a range of SpyCEP constructs to investigate the protein domains and catalytic residues necessary for enzyme function. We designed a high-throughput mass spectrometry assay to measure CXCL8 cleavage and applied this for the first time to study the enzyme kinetics of SpyCEP. Results revealed a remarkably low Michaelis-Menton constant (KM) of 82 nM and a turnover of 1.65 molecules per second. We found that an N-terminally-truncated SpyCEP C-terminal construct containing just the catalytic dyad of H279 and S617 was capable of cleaving CXCL8 with a similar KM of 55 nM, albeit with a reduced substrate turnover of 2.7 molecules per hour, representing a 2200-fold reduction in activity. We conclude that the SpyCEP C-terminus plays a key role in high affinity substrate recognition and binding, but that the N-terminus is required for full catalytic activity.
McKenna S, Aylward F, Miliara X, et al., 2023, The protease associated (PA) domain in ScpA from Streptococcus pyogenes plays a role in substrate recruitment, BBA: Proteins and Proteomics, Vol: 1871, Pages: 1-11, ISSN: 1570-9639
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.
Giblin SP, Ranawana S, Hassibi S, et al., 2023, CXCL17 binds efficaciously to glycosaminoglycans with the potential to modulate chemokine signaling, Frontiers in Immunology, Vol: 14, ISSN: 1664-3224
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 techniquesResults: 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 r
Giblin SP, Pease JE, 2023, What defines a chemokine? - The curious case of CXCL17, Cytokine, Vol: 168, ISSN: 1096-0023
Chemotactic cytokines (chemokines) are a group of around 40 small proteins which share a similar protein fold and are well known for their ability to direct the migration of leukocytes to a variety of tissue locations. CXCL17 was the last member of the chemokine family to be assigned and was admitted to the family based on theoretical modelling of the CXCL17 structure and chemotactic activity for monocytes and dendritic cells. Of Interest, CXCL17 expression appears to be restricted to mucosal tissues such as the tongue, stomach and lung, suggestive of specific roles at these locations. A putative CXCL17 receptor, GPR35 was reportedly identified and mice deficient in CXCL17 were generated and characterised.More recently, however, some apparent contradictions regarding aspects of CXCL17 biology have been raised by ourselves and others. Notably, GPR35 appears to be a receptor for the serotonin metabolite 5-hydroxyindoleacetic acid rather than for CXCL17 and modelling of CXCL17 using a variety of platforms fails to identify a chemokine-like fold. In this article, we summarize the discovery of CXCL17 and discuss key papers describing the subsequent characterisation of this protein. Ultimately, we pose the question, ‘What defines a chemokine?’
Pyle C, Patel D, Peiro T, et al., 2022, MMP-12 supports pulmonary B cell follicle formation and local antibody responses during asthma, American Journal of Respiratory and Critical Care Medicine, Vol: 206, Pages: 1424-1428, ISSN: 1073-449X
McKenna S, Huse KK, Giblin S, et al., 2022, The role of streptococcal cell-envelope proteases in bacterial evasion of the innate immune system, Journal of Innate Immunity, Vol: 14, Pages: 69-88, ISSN: 1662-811X
Bacteria possess the ability to evolve varied and ingenious strategies to outwit the host immune system, instigating an evolutionary arms race. Proteases are amongst the many weapons employed by bacteria, which specifically cleave and neutralize key signalling molecules required for a coordinated immune response. In this article, we focus on a family of S8 subtilisin-like serine proteases expressed as cell-envelope proteases (CEPs) by group A and group B streptococci. Two of these proteases known as Streptococcus pyogenes CEP (SpyCEP) and C5a peptidase cleave the chemokine CXCL8 and the complement fragment C5a, respectively. Both CXCL8 and C5a are potent neutrophil-recruiting chemokines, and by neutralizing their activity, streptococci evade a key defence mechanism of innate immunity. We review the mechanisms by which CXCL8 and C5a recruit neutrophils and the characterization of SpyCEP and C5a peptidase, including both in vitro and in vivo studies. Recently described structural insights into the function of this CEP family are also discussed. We conclude by examining the progress of prototypic vaccines incorporating SpyCEP and C5a peptidase in their preparation. Since streptococci-producing SpyCEP and C5a peptidase are responsible for a considerable global disease burden, targeting these proteases by vaccination strategies or by small-molecule antagonists should provide protection from and promote the resolution of streptococcal infections.
McKenna S, Giblin SP, Bunn RA, et al., 2021, A highly efficient method for the production and purification of recombinant human CXCL8, PLoS One, Vol: 16, Pages: 1-12, ISSN: 1932-6203
Chemokines play diverse and fundamental roles in the immune system and human disease, which has prompted their structural and functional characterisation. Production of recombinant chemokines that are folded and bioactive is vital to their study but is limited by the stringent requirements of a native N-terminus for receptor activation and correct disulphide bonding required to stabilise the chemokine fold. Even when expressed as fusion proteins, overexpression of chemokines in E. coli tends to result in the formation of inclusion bodies, generating the additional steps of solubilisation and refolding. Here we present a novel method for producing soluble chemokines in relatively large amounts via a simple two-step purification procedure with no requirements for refolding. CXCL8 produced by this method has the correct chemokine fold as determined by NMR spectroscopy and in chemotaxis assays was indistinguishable from commercially available chemokines. We believe that this protocol significantly streamlines the generation of recombinant chemokines.
Pease JE, 2021, C5a anaphylatoxin chemotactic receptor 1 (C5aR1) antagonist: treatment of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, Drugs of the Future, Vol: 46, Pages: 183-190, ISSN: 0377-8282
Inflammation is a key component of several clinicallyimportant disorders, with the recruitment of neutrophils oftenpivotal to the inflammatory process. Enzymatic activationof the complement cascade results in generation of thecomplement fragment C5a, a potent chemoattractant forneutrophils. C5a functions by binding to 2 specific G proteincoupled receptors named C5aR1 and C5aR2 on the surfaceof neutrophils and drives cell activation and migration.Avacopan (CCX-168) is a small molecule antagonist of C5aR1which was developed by ChemoCentryx. Avacopan bindswith nanomolar affinity to C5aR1 and is a potent inhibitor ofneutrophil recruitment in vitro and in vivo. Avacopan appearsto be well tolerated and in a phase III trial involving individualswith anti-neutrophil cytoplasmic antibody (ANCA)-inducedvasculitis, blockade of C5aR1 by avacopan was reported tobe efficacious in sparing high levels of glucocorticoid usage,providing a potential alternative protocol for the treatmentof relapses.
Motedayen Aval L, Pease JE, Sharma R, et al., 2020, Challenges and opportunities in the clinical development of STING agonists for cancer immunotherapy, Journal of Clinical Medicine, Vol: 9, ISSN: 2077-0383
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.
Matthews S, McKenna S, Malito E, et al., 2020, Structure, dynamics and immunogenicity of a catalytically inactive CXC Chemokine-degrading Protease SpyCEP from Streptococcus pyogenes, Computational and Structural Biotechnology Journal, Vol: 18, Pages: 650-660, ISSN: 2001-0370
Over 18 million disease cases and half a million deaths worldwide are estimated to be caused annually by Group A Streptococcus. A vaccine to prevent GAS disease is urgently needed. SpyCEP (Streptococcus pyogenes Cell-Envelope Proteinase) is a surface-exposed serine protease that inactivates chemokines, impairing neutrophil recruitment and bacterial clearance, and has shown promising immunogenicity in preclinical models. Although SpyCEP structure has been partially characterized, a more complete and higher resolution understanding of its antigenic features would be desirable prior to large scale manufacturing. To address these gaps and facilitate development of this globally important vaccine, we performed immunogenicity studies with a safety-engineered SpyCEP mutant, and comprehensively characterized its structure by combining X-ray crystallography, NMR spectroscopy and molecular dynamics simulations. We found that the catalytically-inactive SpyCEP antigen conferred protection similar to wild-type SpyCEP in a mouse infection model. Further, a new higher-resolution crystal structure of the inactive SpyCEP mutant provided new insights into this large chemokine protease comprising nine domains derived from two non-covalently linked fragments. NMR spectroscopy and molecular simulation analyses revealed conformational flexibility that is likely important for optimal substrate recognition and overall function. These combined immunogenicity and structural data demonstrate that the full-length SpyCEP inactive mutant is a strong candidate human vaccine antigen. These findings show how a multi-disciplinary study was used to overcome obstacles in the development of a GAS vaccine, an approach applicable to other future vaccine programs. Moreover, the information provided may also facilitate the structure-based discovery of small-molecule therapeutics targeting SpyCEP protease inhibition.
Anderson C, Patel P, Viney J, et al., 2020, A degradatory fate for CCR4 suggests a primary role in Th2 inflammation, Journal of Leukocyte Biology, Vol: 107, Pages: 455-466, ISSN: 0741-5400
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.
Lloyd C, Puttur F, Denney L, et al., 2019, Pulmonary environmental cues drive group 2 innate lymphoid cell dynamics in mice and humans, Science Immunology, Vol: 4, ISSN: 2470-9468
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.
Goldblatt J, Hoffland A, Lawrenson RA, et al., 2019, A requirement for neutrophil glycosaminoglycans in chemokine:receptor interactions is revealed by the streptococcal protease SpyCEP, Journal of Immunology, Vol: 202, Pages: 3246-3255, ISSN: 1550-6606
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.
Pease JE, Williams TJ, 2018, Tipping the balance: a biased nanobody antagonist of CCR3 with potential for the treatment of eosinophilic inflammation, Journal of Allergy and Clinical Immunology, Vol: 143, Pages: 552-553, ISSN: 0091-6749
Evans RJ, Hernandez-Gil J, Mohri Z, et al., 2018, DEVELOPING NEW TARGETED MOLECULAR CONTRAST AGENTS FOR IMAGING INFLAMMATION OF VULNERABLE PLAQUES, Annual Meeting of the British-Atherosclerosis-Society (BAS), Publisher: OXFORD UNIV PRESS, Pages: S3-S4, ISSN: 0008-6363
Pontejo S, Murphy P, Pease JE, 2018, Chemokine subversion by human herpesviruses, Journal of Innate Immunity, Vol: 10, Pages: 465-478, ISSN: 1662-811X
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.
Amir NASBM, Mackenzie AE, Jenkins L, et al., 2018, Evidence for the existence of a CXCL17 receptor distinct from GPR35, Journal of Immunology, Vol: 201, Pages: 714-724, ISSN: 0022-1767
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 β-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 towards directional migration along a CXCL17 gradient, which was significantly enhanced by overnight incubation with the prostaglandin 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.
Pease JE, Kausar F, Day A, et al., 2018, CXCL4/Platelet Factor 4 is an agonist of CCR1 and drives human monocyte migration, Scientific Reports, Vol: 8, ISSN: 2045-2322
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.
Pease JE, Williams T, 2018, Eosinophils on trial, Clinical and Experimental Allergy, Vol: 48, Pages: 490-492, ISSN: 0954-7894
Pease JE, 2016, Designing small molecule CXCR3 antagonists., Expert Opinion on Drug Discovery, Vol: 12, Pages: 159-168, ISSN: 1746-045X
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.
Gela A, Kasetty G, Morgelin M, et al., 2016, Osteopontin binds and modulates functions of eosinophil-recruiting chemokines, Allergy, Vol: 71, Pages: 58-67, ISSN: 0105-4538
BackgroundAllergic asthma is characterized by eosinophilic inflammation and airway obstruction. There is also an increased risk of pulmonary infection caused by Streptococcus pneumoniae, in particular during severe asthma where high levels of the glycoprotein, osteopontin (OPN), are present in the airways. Eosinophils can be recruited by chemokines activating the receptor CCR3 including eotaxin-1/CCL11, eotaxin-2/CCL24, eotaxin-3/CCL26, RANTES/CCL5, and MEC/CCL28. In addition to inducing chemotaxis, several of these molecules have defensin-like antibacterial properties. This study set out to elucidate the functional consequences of OPN binding to eosinophil-recruiting chemokines.MethodsAntibacterial activities of the chemokines were investigated using viable count assays and electron microscopy. Binding studies were performed by means of surface plasmon resonance. The potential interference of OPN with antibacterial, receptor-activating, and lipopolysaccharide-neutralizing abilities of these chemokines was investigated.ResultsWe found that OPN bound all eosinophil-recruiting chemokines with high affinity except for CCL5. The eosinophil-recruiting chemokines all displayed bactericidal activity against S. pneumoniae, but only CCL26 and CCL28 retained high antibacterial activity in the presence of sodium chloride at physiologic concentrations. Preincubation of the chemokines with OPN strongly inhibited their antibacterial activity against S. pneumoniae but did not affect their ability to activate CCR3. All chemokines investigated showed LPS-neutralizing activity that was impaired by OPN only in the case of CCL24.ConclusionsThe data suggest that OPN may impair host defense activities of the chemokines without affecting their eosinophil-recruiting properties. This could be one mechanism explaining the increased vulnerability to acquire pneumococcal infection in parallel with sustained allergic inflammation in asthma.
Anderson CA, Solari R, Pease JE, 2015, Biased agonism at chemokine receptors: obstacles or opportunities for drug discovery?, Journal of Leukocyte Biology, Vol: 99, Pages: 901-909, ISSN: 0741-5400
Gostner JM, Raggl E, Becker K, et al., 2015, Bisphenol A suppresses Th1-type immune response in human peripheral blood mononuclear cells <i>in vitro</i>, IMMUNOLOGY LETTERS, Vol: 168, Pages: 285-292, ISSN: 0165-2478
- Author Web Link
- Cite
- Citations: 23
Denney L, Byrne A, Shea T, et al., 2015, Pulmonary epithelial cell-derived cytokine TGF-β1 Is a critical cofactor for enhanced innate lymphoid cell function, Immunity, Vol: 43, Pages: 945-958, ISSN: 1097-4180
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-β had a central role in the generation of the pulmonary immune response. Mice that specifically lacked epithelial cell-derived TGF-β1 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-β by expressing the receptor TGF-βRII and ILC chemoactivity was enhanced by TGF-β. 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.
Weiss M, Byrne AJ, Blazek K, et al., 2015, IRF5 controls both acute and chronic inflammation, Proceedings of the National Academy of Sciences of the United States of America, Vol: 112, Pages: 11001-11006, ISSN: 0027-8424
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.
Gela A, Kasetty G, Jovic S, et al., 2015, Eotaxin-3 exerts innate host defense activities that are modulated by mast cell proteases, Publisher: EUROPEAN RESPIRATORY SOC JOURNALS LTD, ISSN: 0903-1936
Solari R, Pease JE, 2015, Targeting chemokine receptors in disease - a case study of CCR4., European Journal of Pharmacology, Vol: 763, Pages: 167-177, ISSN: 0014-2999
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.
Blazek K, Eames HL, Weiss M, et al., 2015, IFN-lambda resolves inflammation via suppression of neutrophil infiltration and IL-1 beta production, Journal of Experimental Medicine, Vol: 212, Pages: 845-853, ISSN: 0022-1007
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.IFN-λ1, -λ2, and -λ3 (or IL-29, IL-28A, and IL-28B, respectively) are members of the class II cytokine family evolutionarily related to both IL-10 and type I IFNs (IFN-α/β), and are collectively referred to as type III IFNs. IFN-λ1 (IL-29) is the main cytokine of this family produced in human cells, but it is not expressed in mice, where IL-28A/B play the major role. Despite the use of a distinct receptor complex, IFNLR1–IL28RA activates similar signaling pathways to that of the type I IFN receptor (Kotenko et al., 2003; Sheppard et al., 2003), and the most studied biological role of IFN-λs has so far been their antiviral activity. However, there is evidence to suggest that they may also have pleiotropic immune functions. IF
Nedjai B, Viney JM, Li H, et al., 2015, CXCR3 antagonist VUF10085 binds to an intrahelical site distinct from that of the broad spectrum antagonist TAK-779, BRITISH JOURNAL OF PHARMACOLOGY, Vol: 172, Pages: 1822-1833, ISSN: 0007-1188
- Author Web Link
- Open Access Link
- Cite
- Citations: 11
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.