ORCID Profile
0000-0001-8151-8781
Current Organisation
University of Oxford
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Publisher: Wiley
Date: 26-09-2014
DOI: 10.1002/ART.38755
Abstract: Tumor necrosis factor (TNF) signals via 2 receptors, TNFR type I (TNFRI) and TNFRII, with distinct cellular distribution and signaling functions. In rheumatoid arthritis (RA), the net effect of TNFR signaling favors inflammatory responses while inhibiting the activity of regulatory T cells. TNFRII signaling has been shown to promote Treg cell function. To assess the relative contributions of TNFRI and TNFRII signaling to inflammatory and regulatory responses in vivo, we compared the effect of TNF blockade, hence TNFRI/II, versus TNFRI alone in collagen-induced arthritis (CIA) as a model of RA. Mice with established arthritis were treated for 10 days with anti-mouse TNFRI domain antibody (dAb DMS5540), an isotype control dAb (DMS5538), or murine TNFRII genetically fused with mouse IgG1 Fc domain (mTNFRII-Fc) beginning on the day of arthritis onset, and disease progression was monitored. Systemic cytokine concentrations and numbers of T cell subsets in lymph nodes and spleens were measured, and intrinsic Treg cell function was determined by ex vivo suppression assays. Progression of CIA was suppressed similarly by TNFRI (DMS5540) and TNFRI/II (mTNFRII-Fc) blockade. However, blockade of TNFRI/II led to increased effector T cell activity, which was not observed after selective TNFRI blockade, suggesting an immunoregulatory role of TNFRII. In support of this, TNFRI blockade, but not TNFRI/II blockade, expanded and activated Treg cells. Furthermore, a dramatic increase in expression of the Treg cell signature genes FoxP3 and TNFRII was observed in joints undergoing remission, which supports the notion that these molecules have a physiologic role in the resolution of inflammation. We propose that a therapeutic strategy that targets TNFRI while sparing TNFRII has the potential to both inhibit inflammation and promote Treg cell activity, which might be superior to TNF blockade.
Publisher: The Company of Biologists
Date: 2020
DOI: 10.1242/BIO.049809
Abstract: Mechanical force is a fundamental regulator of cell phenotype. Myofibroblasts are central mediators of fibrosis, a major unmet clinical need characterized by the deposition of excessive matrix proteins. Traction forces of myofibroblasts play a key role in remodelling the matrix and modulates the activities of embedded stromal cells. Here, we employ a combination of unsupervised computational analysis, cytoskeletal profiling and single cell traction force microscopy as functional readout to uncover how the complex spatiotemporal dynamics and mechanics of living human myofibroblast shape sub-cellular profiling of traction forces in fibrosis. We resolve distinct biophysical communities of myofibroblasts, and our results provide a new paradigm for studying functional heterogeneity in human stromal cells.
Publisher: Rockefeller University Press
Date: 04-05-2015
DOI: 10.1084/JEM.20140995
Abstract: 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 lification 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.
Publisher: Proceedings of the National Academy of Sciences
Date: 27-01-2014
Abstract: Current therapies to alleviate autoimmune conditions use global strategies that affect large compartments of the immune response. These strategies mop up the excesses of disease without slowing disease progression and carry a significant risk of infection. This article describes the selective inhibition of autoaggressive T cells with the ability to regress established arthritis and reveals an unexpected role for an immune receptor–ligand pair in bone homeostasis.
Publisher: Elsevier BV
Date: 09-2005
DOI: 10.1016/J.CELL.2005.06.025
Abstract: Dietary heme iron is an important nutritional source of iron in carnivores and omnivores that is more readily absorbed than non-heme iron derived from vegetables and grain. Most heme is absorbed in the proximal intestine, with absorptive capacity decreasing distally. We utilized a subtractive hybridization approach to isolate a heme transporter from duodenum by taking advantage of the intestinal gradient for heme absorption. Here we show a membrane protein named HCP 1 (heme carrier protein 1), with homology to bacterial metal-tetracycline transporters, mediates heme uptake by cells in a temperature-dependent and saturable manner. HCP 1 mRNA was highly expressed in duodenum and regulated by hypoxia. HCP 1 protein was iron regulated and localized to the brush-border membrane of duodenal enterocytes in iron deficiency. Our data indicate that HCP 1 is the long-sought intestinal heme transporter.
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Fiona McCann.