Publications by authors named "Anthony Coyle"

138 Publications

Human amyotrophic lateral sclerosis excitability phenotype screen: Target discovery and validation.

Cell Rep 2021 Jun;35(10):109224

F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA. Electronic address:

Drug development is hampered by poor target selection. Phenotypic screens using neurons differentiated from patient stem cells offer the possibility to validate known and discover novel disease targets in an unbiased fashion. To identify targets for managing hyperexcitability, a pathological feature of amyotrophic lateral sclerosis (ALS), we design a multi-step screening funnel using patient-derived motor neurons. High-content live cell imaging is used to evaluate neuronal excitability, and from a screen against a chemogenomic library of 2,899 target-annotated compounds, 67 reduce the hyperexcitability of ALS motor neurons carrying the SOD1(A4V) mutation, without cytotoxicity. Bioinformatic deconvolution identifies 13 targets that modulate motor neuron excitability, including two known ALS excitability modulators, AMPA receptors and Kv7.2/3 ion channels, constituting target validation. We also identify D2 dopamine receptors as modulators of ALS motor neuron excitability. This screen demonstrates the power of human disease cell-based phenotypic screens for identifying clinically relevant targets for neurological disorders.
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http://dx.doi.org/10.1016/j.celrep.2021.109224DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8209673PMC
June 2021

TLR Stimulation Produces IFN-β as the Primary Driver of IFN Signaling in Nonlymphoid Primary Human Cells.

Immunohorizons 2020 06 18;4(6):332-338. Epub 2020 Jun 18.

Centers for Therapeutic Innovation, Pfizer Inc., Cambridge, MA 02139;

Several human autoimmune diseases are characterized by increased expression of type 1 IFN-stimulated genes in both the peripheral blood and tissue. The contributions of different type I IFNs to this gene signature are uncertain as the type I IFN family consists of 13 alphas and one each of β, ε, κ, and ω subtypes. We sought to investigate the contribution of various IFNs to IFN signaling in primary human cell types. We stimulated primary skin, muscle, kidney, and PBMCs from normal healthy human donors with various TLR ligands and measured the expression of type I IFN subtypes and activation of downstream signaling by quantitative PCR. We show that is the dominant type I IFN expressed upon TLR3 and TLR4 stimulation, and its expression profile is associated with subsequent transcription. Furthermore, using an IFN-β-specific neutralizing Ab, we show that expression is inhibited in a dose-dependent manner, suggesting that IFN-β is the primary driver of IFN-stimulated genes following TLR3 and TLR4 engagement. Stimulation with TLR7/8 and TLR9 ligands induced and subtypes and expression only in PBMCs and not in tissue resident cell types. Concordantly, IFN-β neutralization had no effect on expression in PBMCs potentially because of the combination of and expression. Combined, these data highlight the potential role for IFN-β in driving local inflammatory responses in clinically relevant human tissue types and opportunities to treat local inflammation by targeting IFN-β.
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http://dx.doi.org/10.4049/immunohorizons.1800054DOI Listing
June 2020

A human anti-IL-2 antibody that potentiates regulatory T cells by a structure-based mechanism.

Nat Med 2018 07 25;24(7):1005-1014. Epub 2018 Jun 25.

UCSF Diabetes Center, University of California, San Francisco, San Francisco, CA, USA.

Interleukin-2 (IL-2) has been shown to suppress immune pathologies by preferentially expanding regulatory T cells (T). However, this therapy has been limited by off-target complications due to pathogenic cell expansion. Recent efforts have been focused on developing a more selective IL-2. It is well documented that certain anti-mouse IL-2 antibodies induce conformational changes that result in selective targeting of T. We report the generation of a fully human anti-IL-2 antibody, F5111.2, that stabilizes IL-2 in a conformation that results in the preferential STAT5 phosphorylation of T in vitro and selective expansion of T in vivo. When complexed with human IL-2, F5111.2 induced remission of type 1 diabetes in the NOD mouse model, reduced disease severity in a model of experimental autoimmune encephalomyelitis and protected mice against xenogeneic graft-versus-host disease. These results suggest that IL-2-F5111.2 may provide an immunotherapy to treat autoimmune diseases and graft-versus-host disease.
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http://dx.doi.org/10.1038/s41591-018-0070-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6398608PMC
July 2018

Identification of direct negative cross-talk between the SLIT2 and bone morphogenetic protein-Gremlin signaling pathways.

J Biol Chem 2018 03 9;293(9):3039-3055. Epub 2018 Jan 9.

From the Centers for Therapeutic Innovation, Pfizer Inc., Cambridge, Massachusetts 02139,

Slit guidance ligand 2 (SLIT2) is a large, secreted protein that binds roundabout (ROBO) receptors on multiple cell types, including neurons and kidney podocytes. SLIT2-ROBO-mediated signaling regulates neuronal migration and ureteric bud (UB) outgrowth during kidney development as well as glomerular filtration in adult kidneys. Additionally, SLIT2 binds Gremlin, an antagonist of bone morphogenetic proteins (BMPs), and BMP-Gremlin signaling also regulates UB formation. However, direct cross-talk between the ROBO2-SLIT2 and BMP-Gremlin signaling pathways has not been established. Here, we report the discovery of negative feedback between the SLIT2 and BMP-Gremlin signaling pathways. We found that the SLIT2-Gremlin interaction inhibited both SLIT2-ROBO2 signaling in neurons and Gremlin antagonism of BMP activity in myoblasts and fibroblasts. Furthermore, BMP2 down-regulated SLIT2 expression and promoter activity through canonical BMP signaling. Gremlin treatment, BMP receptor inhibition, and SMAD family member 4 (SMAD4) knockdown rescued BMP-mediated repression of SLIT2. BMP2 treatment of nephron progenitor cells derived from human embryonic stem cells decreased SLIT2 expression, further suggesting an interaction between the BMP2-Gremlin and SLIT2 pathways in human kidney cells. In conclusion, our study has revealed direct negative cross-talk between two pathways, previously thought to be unassociated, that may regulate both kidney development and adult tissue maintenance.
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http://dx.doi.org/10.1074/jbc.M117.804021DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5836125PMC
March 2018

Therapeutic Effects of FGF23 c-tail Fc in a Murine Preclinical Model of X-Linked Hypophosphatemia Via the Selective Modulation of Phosphate Reabsorption.

J Bone Miner Res 2017 Oct 25;32(10):2062-2073. Epub 2017 Aug 25.

Center for Therapeutic Innovation, Pfizer, New York, NY, USA.

Fibroblast growth factor 23 (FGF23) is the causative factor of X-linked hypophosphatemia (XLH), a genetic disorder effecting 1:20,000 that is characterized by excessive phosphate excretion, elevated FGF23 levels and a rickets/osteomalacia phenotype. FGF23 inhibits phosphate reabsorption and suppresses 1α,25-dihydroxyvitamin D (1,25D) biosynthesis, analytes that differentially contribute to bone integrity and deleterious soft-tissue mineralization. As inhibition of ligand broadly modulates downstream targets, balancing efficacy and unwanted toxicity is difficult when targeting the FGF23 pathway. We demonstrate that a FGF23 c-tail-Fc fusion molecule selectively modulates the phosphate pathway in vivo by competitive antagonism of FGF23 binding to the FGFR/α klotho receptor complex. Repeated injection of FGF23 c-tail Fc in Hyp mice, a preclinical model of XLH, increases cell surface abundance of kidney NaPi transporters, normalizes phosphate excretion, and significantly improves bone architecture in the absence of soft-tissue mineralization. Repeated injection does not modulate either 1,25D or calcium in a physiologically relevant manner in either a wild-type or disease setting. These data suggest that bone integrity can be improved in models of XLH via the exclusive modulation of phosphate. We posit that the selective modulation of the phosphate pathway will increase the window between efficacy and safety risks, allowing increased efficacy to be achieved in the treatment of this chronic disease. © 2017 American Society for Bone and Mineral Research.
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http://dx.doi.org/10.1002/jbmr.3197DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5816679PMC
October 2017

SLIT2/ROBO2 signaling pathway inhibits nonmuscle myosin IIA activity and destabilizes kidney podocyte adhesion.

JCI Insight 2016 Nov 17;1(19):e86934. Epub 2016 Nov 17.

Renal Section, Department of Medicine, Boston University Medical Center, Boston, Massachusetts, USA.

The repulsive guidance cue SLIT2 and its receptor ROBO2 are required for kidney development and podocyte foot process structure, but the SLIT2/ROBO2 signaling mechanism regulating podocyte function is not known. Here we report that a potentially novel signaling pathway consisting of SLIT/ROBO Rho GTPase activating protein 1 (SRGAP1) and nonmuscle myosin IIA (NMIIA) regulates podocyte adhesion downstream of ROBO2. We found that the myosin II regulatory light chain (MRLC), a subunit of NMIIA, interacts directly with SRGAP1 and forms a complex with ROBO2/SRGAP1/NMIIA in the presence of SLIT2. Immunostaining demonstrated that SRGAP1 is a podocyte protein and is colocalized with ROBO2 on the basal surface of podocytes. In addition, SLIT2 stimulation inhibits NMIIA activity, decreases focal adhesion formation, and reduces podocyte attachment to collagen. In vivo studies further showed that podocyte-specific knockout of protects mice from hypertension-induced podocyte detachment and albuminuria and also partially rescues the podocyte-loss phenotype in knockout mice. Thus, we have identified SLIT2/ROBO2/SRGAP1/NMIIA as a potentially novel signaling pathway in kidney podocytes, which may play a role in regulating podocyte adhesion and attachment. Our findings also suggest that SLIT2/ROBO2 signaling might be a therapeutic target for kidney diseases associated with podocyte detachment and loss.
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http://dx.doi.org/10.1172/jci.insight.86934DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5111509PMC
November 2016

Factor XIa-specific IgG and a reversal agent to probe factor XI function in thrombosis and hemostasis.

Sci Transl Med 2016 08;8(353):353ra112

Cardiovascular Research Institute, University of California, San Francisco, Room SC452P, 555 Mission Bay Boulevard South, San Francisco, CA 94143-3122, USA.

Thrombosis is a major cause of morbidity and mortality. Current antithrombotic drugs are not ideal in that they must balance prevention of thrombosis against bleeding risk. Inhibition of coagulation factor XI (FXI) may offer an improvement over existing antithrombotic strategies by preventing some forms of thrombosis with lower bleeding risk. To permit exploration of this hypothesis in humans, we generated and characterized a series of human immunoglobulin Gs (IgGs) that blocked FXIa active-site function but did not bind FXI zymogen or other coagulation proteases. The most potent of these IgGs, C24 and DEF, inhibited clotting in whole human blood and prevented FeCl3-induced carotid artery occlusion in FXI-deficient mice reconstituted with human FXI and in thread-induced venous thrombosis in rabbits at clinically relevant doses. At doses substantially higher than those required for inhibition of intravascular thrombus formation in these models, DEF did not increase cuticle bleeding in rabbits or cause spontaneous bleeding in macaques over a 2-week study. Anticipating the desirability of a reversal agent, we also generated a human IgG that rapidly reversed DEF activity ex vivo in human plasma and in vivo in rabbits. Thus, an active site-directed FXIa-specific antibody can block thrombosis in animal models and, together with the reversal agent, may facilitate exploration of the roles of FXIa in human disease.
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http://dx.doi.org/10.1126/scitranslmed.aaf4331DOI Listing
August 2016

Type I IFNs Regulate Inflammation, Vasculopathy, and Fibrosis in Chronic Cutaneous Graft-versus-Host Disease.

J Immunol 2016 07 25;197(1):42-50. Epub 2016 May 25.

Centers for Therapeutic Innovation, Pfizer, Inc., Boston, MA 02115.

Type I IFNs play a critical role in the immune response to viral infection and may also drive autoimmunity through modulation of monocyte maturation and promotion of autoreactive lymphocyte survival. Recent demonstrations of type I IFN gene signatures in autoimmune diseases, including scleroderma, led us to investigate the pathological role of IFNs in a preclinical model of sclerodermatous graft-versus-host disease. Using a neutralizing Ab against the type I IFN receptor IFNAR1, we observed a marked reduction in dermal inflammation, vasculopathy, and fibrosis compared with that seen in the presence of intact IFNAR1 signaling. The ameliorative effects of IFNAR1 blockade were restricted to the skin and were highly associated with inhibition of chronic vascular injury responses and not due to the inhibition of the T or B cell alloresponse. Inhibition of IFNAR1 normalized the overexpression of IFN-inducible genes in graft-versus-host disease skin and markedly reduced dermal IFN-α levels. Depletion of plasmacytoid dendritic cells, a major cellular source of type I IFNs, did not reduce the severity of fibrosis or type I IFN gene signature in the skin. Taken together, these studies demonstrate an important role for type I IFN in skin fibrosis, and they provide a rationale for IFNAR1 inhibition in scleroderma.
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http://dx.doi.org/10.4049/jimmunol.1502190DOI Listing
July 2016

Characterization of Tiki, a New Family of Wnt-specific Metalloproteases.

J Biol Chem 2016 Jan 2;291(5):2435-43. Epub 2015 Dec 2.

From the F. M. Kirby Neurobiology Center, Boston Children's Hospital, Department of Neurology, Harvard Medical School, Boston, Massachusetts 02115 and

The Wnt family of secreted glycolipoproteins plays pivotal roles in development and human diseases. Tiki family proteins were identified as novel Wnt inhibitors that act by cleaving the Wnt amino-terminal region to inactivate specific Wnt ligands. Tiki represents a new metalloprotease family that is dependent on Mn(2+)/Co(2+) but lacks known metalloprotease motifs. The Tiki extracellular domain shares homology with bacterial TraB/PrgY proteins, known for their roles in the inhibition of mating pheromones. The TIKI/TraB fold is predicted to be distantly related to structures of additional bacterial proteins and may use a core β-sheet within an α+β-fold to coordinate conserved residues for catalysis. In this study, using assays for Wnt3a cleavage and signaling inhibition, we performed mutagenesis analyses of human TIKI2 to examine the structural prediction and identify the active site residues. We also established an in vitro assay for TIKI2 protease activity using FRET peptide substrates derived from the cleavage motifs of Wnt3a and Xenopus wnt8 (Xwnt8). We further identified two pairs of potential disulfide bonds that reside outside the β-sheet catalytic core but likely assist the folding of the TIKI domain. Finally, we systematically analyzed TIKI2 cleavage of the 19 human WNT proteins, of which we identified 10 as potential TIKI2 substrates, revealing the hydrophobic nature of Tiki cleavage sites. Our study provides insights into the Tiki family of proteases and its Wnt substrates.
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http://dx.doi.org/10.1074/jbc.M115.677807DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4732225PMC
January 2016

EGF-receptor specificity for phosphotyrosine-primed substrates provides signal integration with Src.

Nat Struct Mol Biol 2015 Dec 9;22(12):983-90. Epub 2015 Nov 9.

Division of Signal Transduction, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA.

Aberrant activation of the EGF receptor (EGFR) contributes to many human cancers by activating the Ras-MAPK pathway and other pathways. EGFR signaling is augmented by Src-family kinases, but the mechanism is poorly understood. Here, we show that human EGFR preferentially phosphorylates peptide substrates that are primed by a prior phosphorylation. Using peptides based on the sequence of the adaptor protein Shc1, we show that Src mediates the priming phosphorylation, thus promoting subsequent phosphorylation by EGFR. Importantly, the doubly phosphorylated Shc1 peptide binds more tightly than singly phosphorylated peptide to the Ras activator Grb2; this binding is a key step in activating the Ras-MAPK pathway. Finally, a crystal structure of EGFR in complex with a primed Shc1 peptide reveals the structural basis for EGFR substrate specificity. These results provide a molecular explanation for the integration of Src and EGFR signaling with downstream effectors such as Ras.
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http://dx.doi.org/10.1038/nsmb.3117DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4824005PMC
December 2015

Resolution of Skin Fibrosis by Neutralization of the Antifibrinolytic Function of Plasminogen Activator Inhibitor 1.

Arthritis Rheumatol 2016 Feb;68(2):473-83

MedImmune LLC, Gaithersburg, Maryland.

Objective: Systemic sclerosis (SSc) is a fibrotic disease characterized by an obliterative vasculopathy with thrombosis and impairment of the coagulation-fibrinolysis balance. Plasminogen activator inhibitor 1 (PAI-1) is the major inhibitor of profibrinolytic plasminogen activators (PAs). This study was undertaken to evaluate the contribution of PAI-1 to SSc pathology in the skin.

Methods: PAI-1 was evaluated in skin from patients with diffuse SSc (dSSc) and those with limited SSc (lSSc) by immunohistochemistry. The contribution of PAI-1 to SSc pathology was tested in vivo in murine graft-versus-host disease (GVHD) and bleomycin models of progressive skin fibrosis and in vitro in dermal human microvascular endothelial cells (HMVECs) using a monoclonal antibody that selectively prevents the binding of PAI-1 to PA.

Results: Skin from patients with dSSc and those with lSSc showed increased PAI-1 levels in the epidermis and microvessel endothelium. PAI-1 neutralization in the GVHD model led to a dramatic, dose-dependent improvement in clinical skin score, concomitant with vasculopathy resolution, including a reduction in fibrinolysis regulators and vascular injury markers, as well as reduced inflammation. Resolution of vasculopathy and inflammation was associated with resolution of skin fibrosis, as assessed by reduction in collagen content and expression of key profibrotic mediators, including transforming growth factor β1 and tissue inhibitor of metalloproteinases 1. Similar to the GVHD model, PAI-1 neutralization reduced dermal inflammation and fibrosis in the bleomycin model. PAI-1 neutralization stimulated plasmin-mediated metalloproteinase 1 activation in dermal HMVECs.

Conclusion: Our findings indicate that neutralization of the antifibrinolytic function of PAI-1 resolves skin fibrosis by limiting the extent of initial vascular injury and connective tissue inflammation. These data suggest that PAI-1 represents an important checkpoint in disease pathology in human SSc.
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http://dx.doi.org/10.1002/art.39443DOI Listing
February 2016

Novel Anti-TM4SF1 Antibody-Drug Conjugates with Activity against Tumor Cells and Tumor Vasculature.

Mol Cancer Ther 2015 Aug 18;14(8):1868-76. Epub 2015 Jun 18.

The Center for Vascular Biology Research and the Departments of Pathology, Beth Israel Deaconess Medical Center (BIDMC) and Harvard Medical School, Boston, Massachusetts.

Antibody-drug conjugates (ADC) represent a promising therapeutic modality for managing cancer. Here, we report a novel humanized ADC that targets the tetraspanin-like protein TM4SF1. TM4SF1 is highly expressed on the plasma membranes of many human cancer cells and also on the endothelial cells lining tumor blood vessels. TM4SF1 is internalized upon interaction with antibodies. We hypothesized that an ADC against TM4SF1 would inhibit cancer growth directly by killing cancer cells and indirectly by attacking the tumor vasculature. We generated a humanized anti-human TM4SF1 monoclonal antibody, v1.10, and armed it with an auristatin cytotoxic agent LP2 (chemical name mc-3377). v1.10-LP2 selectively killed cultured human tumor cell lines and human endothelial cells that express TM4SF1. Acting as a single agent, v1.10-LP2 induced complete regression of several TM4SF1-expressing tumor xenografts in nude mice, including non-small cell lung cancer and pancreas, prostate, and colon cancers. As v1.10 did not react with mouse TM4SF1, it could not target the mouse tumor vasculature. Therefore, we generated a surrogate anti-mouse TM4SF1 antibody, 2A7A, and conjugated it to LP2. At 3 mpk, 2A7A-LP2 regressed several tumor xenografts without noticeable toxicity. Combination therapy with v1.10-LP2 and 2A7A-LP2 together was more effective than either ADC alone. These data provide proof-of-concept that TM4SF1-targeting ADCs have potential as anticancer agents with dual action against tumor cells and the tumor vasculature. Such agents could offer exceptional therapeutic value and warrant further investigation. Mol Cancer Ther; 14(8); 1868-76. ©2015 AACR.
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http://dx.doi.org/10.1158/1535-7163.MCT-15-0188DOI Listing
August 2015

Brown fat determination and development from muscle precursor cells by novel action of bone morphogenetic protein 6.

PLoS One 2014 21;9(3):e92608. Epub 2014 Mar 21.

Centers for Therapeutic Innovation, Pfizer Inc., Boston, Massachusetts, United States of America.

Brown adipose tissue (BAT) plays a pivotal role in promoting energy expenditure by the virtue of uncoupling protein-1 (UCP-1) that differentiates BAT from its energy storing white adipose tissue (WAT) counterpart. The clinical implication of "classical" BAT (originates from Myf5 positive myoblastic lineage) or the "beige" fat (originates through trans-differentiation of WAT) activation in improving metabolic parameters is now becoming apparent. However, the inducers and endogenous molecular determinants that govern the lineage commitment and differentiation of classical BAT remain obscure. We report here that in the absence of any forced gene expression, stimulation with bone morphogenetic protein 6 (BMP6) induces brown fat differentiation from skeletal muscle precursor cells of murine and human origins. Through a comprehensive transcriptional profiling approach, we have discovered that two days of BMP6 stimulation in C2C12 myoblast cells is sufficient to induce genes characteristic of brown preadipocytes. This developmental switch is modulated in part by newly identified regulators, Optineurin (Optn) and Cyclooxygenase-2 (Cox2). Furthermore, pathway analyses using the Causal Reasoning Engine (CRE) identified additional potential causal drivers of this BMP6 induced commitment switch. Subsequent analyses to decipher key pathway that facilitates terminal differentiation of these BMP6 primed cells identified a key role for Insulin Like Growth Factor-1 Receptor (IGF-1R). Collectively these data highlight a therapeutically innovative role for BMP6 by providing a means to enhance the amount of myogenic lineage derived brown fat.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0092608PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3962431PMC
November 2014

A GM-CSF/IL-33 pathway facilitates allergic airway responses to sub-threshold house dust mite exposure.

PLoS One 2014 14;9(2):e88714. Epub 2014 Feb 14.

Department of Pathology and Molecular Medicine, McMaster Immunology Research Centre, Hamilton, Ontario, Canada.

Allergic asthma is a chronic immune-inflammatory disease of the airways. Despite aeroallergen exposure being universal, allergic asthma affects only a fraction of individuals. This is likely related, at least in part, to the extent of allergen exposure. Regarding house dust mite (HDM), we previously identified the threshold required to elicit allergic responses in BALB/c mice. Here, we investigated the impact of an initial immune perturbation on the response to sub-threshold HDM exposure. We show that transient GM-CSF expression in the lung facilitated robust eosinophilic inflammation, long-lasting antigen-specific Th2 responses, mucus production and airway hyperresponsiveness. This was associated with increased IL-33 levels and activated CD11b(+) DCs expressing OX40L. GM-CSF-driven allergic responses were significantly blunted in IL-33-deficient mice. IL-33 was localized on alveolar type II cells and in vitro stimulation of human epithelial cells with GM-CSF enhanced intracellular IL-33 independently of IL-1α. Likewise, GM-CSF administration in vivo resulted in increased levels of IL-33 but not IL-1α. These findings suggest that exposures to environmental agents associated with GM-CSF production, including airway infections and pollutants, may decrease the threshold of allergen responsiveness and, hence, increase the susceptibility to develop allergic asthma through a GM-CSF/IL-33/OX40L pathway.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0088714PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3925157PMC
October 2014

RAGE is a nucleic acid receptor that promotes inflammatory responses to DNA.

J Exp Med 2013 Oct 30;210(11):2447-63. Epub 2013 Sep 30.

Department of Medicine, Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01605.

Recognition of DNA and RNA molecules derived from pathogens or self-antigen is one way the mammalian immune system senses infection and tissue damage. Activation of immune signaling receptors by nucleic acids is controlled by limiting the access of DNA and RNA to intracellular receptors, but the mechanisms by which endosome-resident receptors encounter nucleic acids from the extracellular space are largely undefined. In this study, we show that the receptor for advanced glycation end-products (RAGE) promoted DNA uptake into endosomes and lowered the immune recognition threshold for the activation of Toll-like receptor 9, the principal DNA-recognizing transmembrane signaling receptor. Structural analysis of RAGE-DNA complexes indicated that DNA interacted with dimers of the outermost RAGE extracellular domains, and could induce formation of higher-order receptor complexes. Furthermore, mice deficient in RAGE were unable to mount a typical inflammatory response to DNA in the lung, indicating that RAGE is important for the detection of nucleic acids in vivo.
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http://dx.doi.org/10.1084/jem.20120201DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3804942PMC
October 2013

Noncanonical autophagy is required for type I interferon secretion in response to DNA-immune complexes.

Immunity 2012 Dec 6;37(6):986-997. Epub 2012 Dec 6.

Respiratory, Inflammation and Autoimmunity Research Department, Gaithersburg, MD 20878, USA.

Toll-like receptor-9 (TLR9) is largely responsible for discriminating self from pathogenic DNA. However, association of host DNA with autoantibodies activates TLR9, inducing the pathogenic secretion of type I interferons (IFNs) from plasmacytoid dendritic cells (pDCs). Here, we found that in response to DNA-containing immune complexes (DNA-IC), but not to soluble ligands, IFN-α production depended upon the convergence of the phagocytic and autophagic pathways, a process called microtubule-associated protein 1A/1B-light chain 3 (LC3)-associated phagocytosis (LAP). LAP was required for TLR9 trafficking into a specialized interferon signaling compartment by a mechanism that involved autophagy-related proteins, but not the conventional autophagic preinitiation complex, or adaptor protein-3 (AP-3). Our findings unveil a new role for nonconventional autophagy in inflammation and provide one mechanism by which anti-DNA autoantibodies, such as those found in several autoimmune disorders, bypass the controls that normally restrict the apportionment of pathogenic DNA and TLR9 to the interferon signaling compartment.
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http://dx.doi.org/10.1016/j.immuni.2012.09.014DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3786711PMC
December 2012

Psoriasiform dermatitis is driven by IL-36-mediated DC-keratinocyte crosstalk.

J Clin Invest 2012 Nov 15;122(11):3965-76. Epub 2012 Oct 15.

Institute of Molecular Health Sciences, Molecular Biomedicine, Swiss Federal Institute of Technology (ETH) Zürich, Zürich, Switzerland.

Psoriasis is a chronic inflammatory disorder of the skin affecting approximately 2% of the world's population. Accumulating evidence has revealed that the IL-23/IL-17/IL-22 pathway is key for development of skin immunopathology. However, the role of keratinocytes and their crosstalk with immune cells at the onset of disease remains poorly understood. Here, we show that IL-36R-deficient (Il36r-/-) mice were protected from imiquimod-induced expansion of dermal IL-17-producing γδ T cells and psoriasiform dermatitis. Furthermore, IL-36R antagonist-deficient (Il36rn-/-) mice showed exacerbated pathology. TLR7 ligation on DCs induced IL-36-mediated crosstalk with keratinocytes and dermal mesenchymal cells that was crucial for control of the pathological IL-23/IL-17/IL-22 axis and disease development. Notably, mice lacking IL-23, IL-17, or IL-22 were less well protected from disease compared with Il36r-/- mice, indicating an additional distinct activity of IL-36 beyond induction of the pathological IL-23 axis. Moreover, while the absence of IL-1R1 prevented neutrophil infiltration, it did not protect from acanthosis and hyperkeratosis, demonstrating that neutrophils are dispensable for disease manifestation. These results highlight a central and unique IL-1-independent role for IL-36 in control of the IL-23/IL-17/IL-22 pathway and development of psoriasiform dermatitis.
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http://dx.doi.org/10.1172/JCI63451DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3484446PMC
November 2012

IL-33, but not thymic stromal lymphopoietin or IL-25, is central to mite and peanut allergic sensitization.

J Allergy Clin Immunol 2013 Jan 21;131(1):187-200.e1-8. Epub 2012 Sep 21.

Department of Pathology and Molecular Medicine, McMaster Immunology Research Centre, McMaster University, Hamilton, Ontario, Canada.

Background: Allergen exposure at lung and gut mucosae can lead to aberrant T(H)2 immunity and allergic disease. The epithelium-associated cytokines thymic stromal lymphopoietin (TSLP), IL-25, and IL-33 are suggested to be important for the initiation of these responses.

Objective: We sought to investigate the contributions of TSLP, IL-25, and IL-33 in the development of allergic disease to the common allergens house dust mite (HDM) or peanut.

Methods: Neutralizing antibodies or mice deficient in TSLP, IL-25, or IL-33 signaling were exposed to HDM intranasally or peanut intragastrically, and immune inflammatory and physiologic responses were evaluated. In vitro assays were performed to examine specific dendritic cell (DC) functions.

Results: We showed that experimental HDM-induced allergic asthma and food allergy and anaphylaxis to peanut were associated with TSLP production but developed independently of TSLP, likely because these allergens functionally mimicked TSLP inhibition of IL-12 production and induction of OX40 ligand (OX40L) on DCs. Blockade of OX40L significantly lessened allergic responses to HDM or peanut. Although IL-25 and IL-33 induced OX40L on DCs in vitro, only IL-33 signaling was necessary for intact allergic immunity, likely because of its superior ability to induce DC OX40L and expand innate lymphoid cells in vivo.

Conclusion: These data identify a nonredundant, IL-33-driven mechanism initiating T(H)2 responses to the clinically relevant allergens HDM and peanut. Our findings, along with those in infectious and transgenic/surrogate allergen systems, favor a paradigm whereby multiple molecular pathways can initiate T(H)2 immunity, which has implications for the conceptualization and manipulation of these responses in health and disease.
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http://dx.doi.org/10.1016/j.jaci.2012.08.002DOI Listing
January 2013

Angiopoietin-2 promotes inflammatory activation of human macrophages and is essential for murine experimental arthritis.

Ann Rheum Dis 2012 Aug 22;71(8):1402-10. Epub 2012 Jun 22.

Experimental Immunology, University of Amsterdam, Amsterdam, The Netherlands.

Background: Angiopoietin (Ang)-1 and Ang-2, and their shared receptor Tie2, are expressed in rheumatoid arthritis (RA) synovial tissue, but the cellular targets of Ang signalling and the relative contributions of Ang-1 and Ang-2 to arthritis are poorly understood.

Objectives: To determine the cellular targets of Ang signalling in RA synovial tissue, and the effects of Ang-2 neutralisation in murine collagen-induced arthritis (CIA).

Methods: RA and psoriatic arthritis (PsA) synovial biopsies were examined for expression of Tie2 and activated phospho (p)-Tie2 by quantitative immunohistochemistry and immunofluorescent double staining. Human monocyte and macrophage Tie2 expression was determined by flow cytometry and quantitative PCR. Regulation of macrophage intracellular signalling pathways and gene expression were examined by immunoblotting and ELISA. CIA was assessed in mice treated with saline, control antibody, prednisolone or neutralising anti-Ang-2 antibody.

Results: Expression of synovial Tie2 and p-Tie2 was similar in RA and PsA. Tie2 activation in RA patient synovial tissue was predominantly localised in synovial macrophages and was expressed by human macrophage. Ang-1 and Ang-2 stimulated activation of multiple intracellular signalling pathways, and cooperated with tumour necrosis factor to induce macrophage interleukin 6 and macrophage inflammatory protein 1α production. Ang-2 selectively suppressed macrophage thrombospondin-2 production. Ang-2 neutralisation significantly decreased disease severity, synovial inflammation, neo-vascularisation and joint destruction in established CIA.

Conclusions: The authors identify synovial macrophages as primary targets of Ang signalling in RA, and demonstrate that Ang-2 promotes the pro-inflammatory activation of human macrophages. Ang-2 makes requisite contributions to pathology in CIA, indicating that targeting Ang-2 may be of therapeutic benefit in the treatment of RA.
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http://dx.doi.org/10.1136/annrheumdis-2011-200718DOI Listing
August 2012

Role of YKL-40 in bronchial smooth muscle remodeling in asthma.

Am J Respir Crit Care Med 2012 Apr 26;185(7):715-22. Epub 2012 Jan 26.

Université Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux, Bordeaux, France.

Rationale: Bronchial remodeling, including increased bronchial smooth muscle (BSM) mass, contributes to bronchial obstruction in asthma. However, its mechanisms are complex and remain controversial. Recently, a role of the chitinase 3-like 1 protein (YKL-40) has been evoked in asthma. Indeed, YKL-40 concentration was increased in asthmatic serum, and correlated with asthma severity and subepithelial membrane thickness. Nevertheless, the role of YKL-40 on BSM cells remains to be investigated.

Objectives: To evaluate whether YKL-40 altered the physiologic properties of BSM cells in asthma in vitro and ex vivo.

Methods: We enrolled 40 subjects with asthma, 13 nonsmokers, and 16 smokers. BSM cells were derived from bronchial specimens obtained by either fiberoptic bronchoscopy or lobectomy. We assessed cell proliferation using BrdU, flow cytometry, and cell count; signaling intermediates using Western blot; cell migration using inserts, wound healing, and phalloidin staining; and cell synthesis using ELISA and Western blot. The involvement of protease activated receptor (PAR)-2 was evaluated using blocking antibody and dedicated lentiviral small hairpin RNA. We also determined the BSM area and the YKL-40 staining ex vivo using immunohistochemistry on biopsies from subjects with asthma and control subjects.

Measurements And Main Results: We demonstrated that YKL-40 increased BSM cell proliferation and migration through PAR-2-, AKT-, ERK-, and p38-dependent mechanisms. The increased cell migration was higher in BSM cells of subjects with asthma than that of control subjects. Furthermore, YKL-40 epithelial expression was positively correlated with BSM mass in asthma.

Conclusions: This study indicates that YKL-40 promotes BSM cell proliferation and migration through a PAR-2-dependent mechanism.
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http://dx.doi.org/10.1164/rccm.201105-0915OCDOI Listing
April 2012

Opposing roles of membrane and soluble forms of the receptor for advanced glycation end products in primary respiratory syncytial virus infection.

J Infect Dis 2012 Apr 18;205(8):1311-20. Epub 2012 Jan 18.

Departments of Respiratory, Inflammation and Autoimmunity, Gaithersburg, MD, USA.

Respiratory syncytial virus (RSV), a common respiratory pathogen in infants and the older population, causes pulmonary inflammation and airway occlusion that leads to impairment of lung function. Here, we have established a role for receptor for advanced glycation end products (RAGE) in RSV infection. RAGE-deficient (ager(-/-)) mice were protected from RSV-induced weight loss and inflammation. This protection correlated with an early increase in type I interferons, later decreases in proinflammatory cytokines, and a reduction in viral load. To assess the contribution of soluble RAGE (sRAGE) to RSV-induced disease, wild-type and ager(-/-) mice were given doses of sRAGE following RSV infection. Of interest, sRAGE treatment prevented RSV-induced weight loss and neutrophilic inflammation to a degree similar to that observed in ager(-/-) mice. Our work further elucidates the roles of RAGE in the pathogenesis of respiratory infections and highlights the opposing roles of membrane and sRAGE in modulating the host response to RSV infection.
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http://dx.doi.org/10.1093/infdis/jir826DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3308901PMC
April 2012

Shifting of immune responsiveness to house dust mite by influenza A infection: genomic insights.

J Immunol 2012 Jan 14;188(2):832-43. Epub 2011 Dec 14.

Division of Respiratory Diseases and Allergy, Center for Gene Therapeutics, McMaster University, Hamilton, Ontario L8S 4K1, Canada.

Respiratory viral infections have been associated with an increased incidence of allergic asthma. However, the mechanisms by which respiratory infections facilitate allergic airway disease are incompletely understood. We previously showed that exposure to a low dose of house dust mite (HDM) resulted in enhanced HDM-mediated allergic airway inflammation, and, importantly, marked airway hyperreactivity only when allergen exposure occurred during an acute influenza A infection. In this study, we evaluated the impact of concurrent influenza infection and allergen exposure at the genomic level, using whole-genome microarray. Our data showed that, in contrast to exposure to a low dose of HDM, influenza A infection led to a dramatic increase in gene expression, particularly of TLRs, C-type lectin receptors, several complement components, as well as FcεR1. Additionally, we observed increased expression of a number of genes encoding chemokines and cytokines associated with the recruitment of proinflammatory cells. Moreover, HDM exposure in the context of an influenza A infection resulted in the induction of unique genes, including calgranulin A (S100a8), an endogenous damage-associated molecular pattern and TLR4 agonist. In addition, we observed significantly increased expression of serum amyloid A (Saa3) and serine protease inhibitor 3n (Serpina3n). This study showed that influenza infection markedly increased the expression of multiple gene classes capable of sensing allergens and amplifying the ensuing immune-inflammatory response. We propose that influenza A infection primes the lung environment in such a way as to lower the threshold of allergen responsiveness, thus facilitating the emergence of a clinically significant allergic phenotype.
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http://dx.doi.org/10.4049/jimmunol.1102349DOI Listing
January 2012

IL-1α/IL-1R1 expression in chronic obstructive pulmonary disease and mechanistic relevance to smoke-induced neutrophilia in mice.

PLoS One 2011 6;6(12):e28457. Epub 2011 Dec 6.

Department of Pathology and Molecular Medicine, Centre for Gene Therapeutics, McMaster University, Hamilton, Canada.

Background: Cigarette smoking is the main risk factor for the development of chronic obstructive pulmonary disease (COPD), a major cause of morbidity and mortality worldwide. Despite this, the cellular and molecular mechanisms that contribute to COPD pathogenesis are still poorly understood.

Methodology And Principal Findings: The objective of this study was to assess IL-1 α and β expression in COPD patients and to investigate their respective roles in perpetuating cigarette smoke-induced inflammation. Functional studies were pursued in smoke-exposed mice using gene-deficient animals, as well as blocking antibodies for IL-1α and β. Here, we demonstrate an underappreciated role for IL-1α expression in COPD. While a strong correlation existed between IL-1α and β levels in patients during stable disease and periods of exacerbation, neutrophilic inflammation was shown to be IL-1α-dependent, and IL-1β- and caspase-1-independent in a murine model of cigarette smoke exposure. As IL-1α was predominantly expressed by hematopoietic cells in COPD patients and in mice exposed to cigarette smoke, studies pursued in bone marrow chimeric mice demonstrated that the crosstalk between IL-1α+ hematopoietic cells and the IL-1R1+ epithelial cells regulates smoke-induced inflammation. IL-1α/IL-1R1-dependent activation of the airway epithelium also led to exacerbated inflammatory responses in H1N1 influenza virus infected smoke-exposed mice, a previously reported model of COPD exacerbation.

Conclusions And Significance: This study provides compelling evidence that IL-1α is central to the initiation of smoke-induced neutrophilic inflammation and suggests that IL-1α/IL-1R1 targeted therapies may be relevant for limiting inflammation and exacerbations in COPD.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0028457PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3232226PMC
July 2012

A glycoengineered anti-CD19 antibody with potent antibody-dependent cellular cytotoxicity activity in vitro and lymphoma growth inhibition in vivo.

Br J Haematol 2011 Nov 9;155(4):426-37. Epub 2011 Sep 9.

Department of Research, MedImmune, LLC, Gaithersburg, MD 20787, USA.

Human cluster of differentiation (CD) antigen 19 is a B cell-specific surface antigen and an attractive target for therapeutic monoclonal antibody (mAb) approaches to treat malignancies of B cell origin. MEDI-551 is an affinity-optimized and afucosylated CD19 mAb with enhanced antibody-dependent cellular cytotoxicity (ADCC). The results from in vitro ADCC assays with Natural Killer cells as effector cells, demonstrate that MEDI-551 is effective at lower mAb doses than rituximab with multiple cell lines as well as primary chronic lymphocytic leukaemia and acute lymphoblastic leukaemia samples. Targeting CD19 with MEDI-551 was also effective in several severe combined immunodeficiency lymphoma models. Furthermore, the combination of MEDI-551 with rituximab resulted in prolonged suppression of tumour growth, demonstrating that therapeutic mAbs with overlapping effector function can be combined for greater tumour growth inhibition. Together, the data demonstrate that MEDI-551 has potent antitumour activity in preclinical models of B cell malignancies. The results also suggest that the combination of the ADCC-enhanced CD19 mAb with an anti-CD20 mAb could be a novel approach for the treatment of B cell lymphomas.
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http://dx.doi.org/10.1111/j.1365-2141.2011.08857.xDOI Listing
November 2011

Mycophenolic acid differentially impacts B cell function depending on the stage of differentiation.

J Immunol 2011 Oct 26;187(7):3603-12. Epub 2011 Aug 26.

MedImmune, LLC, Gaithersburg, MD 20878, USA.

Production of pathogenic Abs contributes to disease progression in many autoimmune disorders. The immunosuppressant agent mycophenolic acid (MPA) has shown clinical efficacy for patients with autoimmunity. The goal of these studies was to elucidate the mechanisms of action of MPA on B cells isolated from healthy individuals and autoimmune patients. In this study, we show that MPA significantly inhibited both proliferation and differentiation of primary human B cells stimulated under various conditions. Importantly, MPA did not globally suppress B cell responsiveness or simply induce cell death, but rather selectively inhibited early activation events and arrested cells in the G0/G1 phase of the cell cycle. Furthermore, MPA blocked expansion of both naive and memory B cells and prevented plasma cell (PC) differentiation and Ab production from healthy controls and individuals with rheumatoid arthritis. Finally, whereas MPA potently suppressed Ig secretion from activated primary B cells, terminally differentiated PCs were not susceptible to inhibition by MPA. The target of MPA, IMPDH2, was found to be downregulated in PCs, likely explaining the resistance of these cells to MPA. These results suggest that MPA provides benefit in settings of autoimmunity by directly preventing activation and PC differentiation of B cells; however, MPA is unlikely to impact autoantibody production by preexisting, long-lived PCs.
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http://dx.doi.org/10.4049/jimmunol.1003319DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4180087PMC
October 2011

Distinct immune effector pathways contribute to the full expression of peanut-induced anaphylactic reactions in mice.

J Allergy Clin Immunol 2011 Jun;127(6):1552-61.e1

Department of Pathology and Molecular Medicine, Centre for Gene Therapeutics, McMaster University, Hamilton, Ontario, Canada.

Background: Food-induced anaphylaxis is often a severe allergic reaction characterized by multiorgan dysfunction and a potentially fatal outcome.

Objectives: We sought to investigate the relative contribution of immunoglobulin-dependent effector pathways to anaphylactic responses to food (ie, peanut).

Methods: Wild-type and various mutant mice were sensitized with peanut protein and cholera toxin by means of oral gavage weekly for 4 weeks. Mice were subjected to different cellular depletion and Fc receptor blocking strategies before challenge with peanut 1 week after the last sensitization.

Results: Our data indicate that pathways other than the classical mast cell (MC)-IgE pathway contribute to the full spectrum of anaphylactic reactions to peanut. We show that the single deletion of MCs, basophils, or phagocytes (ie, macrophages) prevents the most significant clinical outcome: death. Remarkably, the combined deficiency of MCs and phagocytes, but not MCs and basophils, averted nearly all clinical and physiological signs of anaphylaxis. Furthermore, blockade of both IgE and IgG1 signaling was necessary to abolish anaphylactic responses to peanut. Although MC responses occurred through IgE and IgG1, phagocyte responses were fully mediated through IgG1.

Conclusions: Peanut-induced anaphylaxis is a process that involves the concerted action of multiple immune effector pathways, and thus interventions targeting a single pathway (eg, MC-IgE) might not be sufficient to fully prevent anaphylactic responses.
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http://dx.doi.org/10.1016/j.jaci.2011.03.044DOI Listing
June 2011

Differential expression and function of breast regression protein 39 (BRP-39) in murine models of subacute cigarette smoke exposure and allergic airway inflammation.

Respir Res 2011 Apr 7;12:39. Epub 2011 Apr 7.

1Medical Sciences Graduate Program, McMaster University, Hamilton, ON,Canada.

Background: While the presence of the chitinase-like molecule YKL40 has been reported in COPD and asthma, its relevance to inflammatory processes elicited by cigarette smoke and common environmental allergens, such as house dust mite (HDM), is not well understood. The objective of the current study was to assess expression and function of BRP-39, the murine equivalent of YKL40 in a murine model of cigarette smoke-induced inflammation and contrast expression and function to a model of HDM-induced allergic airway inflammation.

Methods: CD1, C57BL/6, and BALB/c mice were room air- or cigarette smoke-exposed for 4 days in a whole-body exposure system. In separate experiments, BALB/c mice were challenged with HDM extract once a day for 10 days. BRP-39 was assessed by ELISA and immunohistochemistry. IL-13, IL-1R1, IL-18, and BRP-39 knock out (KO) mice were utilized to assess the mechanism and relevance of BRP-39 in cigarette smoke- and HDM-induced airway inflammation.

Results: Cigarette smoke exposure elicited a robust induction of BRP-39 but not the catalytically active chitinase, AMCase, in lung epithelial cells and alveolar macrophages of all mouse strains tested. Both BRP-39 and AMCase were increased in lung tissue after HDM exposure. Examining smoke-exposed IL-1R1, IL-18, and IL-13 deficient mice, BRP-39 induction was found to be IL-1 and not IL-18 or IL-13 dependent, while induction of BRP-39 by HDM was independent of IL-1 and IL-13. Despite the importance of BRP-39 in cellular inflammation in HDM-induced airway inflammation, BRP-39 was found to be redundant for cigarette smoke-induced airway inflammation and the adjuvant properties of cigarette smoke.

Conclusions: These data highlight the contrast between the importance of BRP-39 in HDM- and cigarette smoke-induced inflammation. While functionally important in HDM-induced inflammation, BRP-39 is a biomarker of cigarette smoke induced inflammation which is the byproduct of an IL-1 inflammatory pathway.
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http://dx.doi.org/10.1186/1465-9921-12-39DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3079621PMC
April 2011

Anthony Coyle.

Authors:
Anthony Coyle

Nat Biotechnol 2011 Mar;29(3):187

Pfizer's Centers for Therapeutic Innovation.

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http://dx.doi.org/10.1038/nbt.1821DOI Listing
March 2011

IL-9 is a Th17-derived cytokine that limits pathogenic activity in organ-specific autoimmune disease.

Eur J Immunol 2011 Apr 24;41(4):952-62. Epub 2011 Feb 24.

Respiratory, Inflammation and Autoimmune Diseases Research, MedImmune, LLC, Gaithersburg, MD, USA.

IL-9 is a pleiotropic cytokine with key functions in tolerance and inflammation, and its expression is considered a hallmark of Th2-lineage cells. Here, we report that human and mouse Th17 cells are a significant source of IL-9. The expression of IL-9 by Th17 cells was strictly dependent on the presence of TGF-β and IL-1β, and inhibited by IL-4. IL-9-deficient Th17 cells induced more severe autoimmune gastritis following transfer to nu/nu recipient mice. Th17 cells did not appear to be the target of IL-9 bioactivity as Th17 expansion and differentiation was comparable using IL-9-deficient CD4(+) cells or when IL-9 was neutralized with antibodies in vitro. However, reduced mast cell activity was associated with the increased pathogenicity of IL-9-deficient Th17 cells. Together, these results demonstrate a previously unappreciated role for IL-9 in dampening the pathogenic activities of Th17 cells.
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http://dx.doi.org/10.1002/eji.201040879DOI Listing
April 2011
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