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Mair I, Besusso D, Saul L, Patel SD, Ravindran R, McPherson RC, Leech MD, O'Connor RA, Anderton SM, Mellanby RJ. PD-1 expression is upregulated on adapted T cells in experimental autoimmune encephalomyelitis but is not required to maintain a hyporesponsive state. Eur J Immunol 2018; 49:112-120. [PMID: 30485411 PMCID: PMC6492152 DOI: 10.1002/eji.201847868] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 10/24/2018] [Accepted: 11/26/2018] [Indexed: 01/09/2023]
Abstract
T cell adaptation is an important peripheral tolerogenic process which ensures that the T cell population can respond effectively to pathogens but remains tolerant to self‐antigens. We probed the mechanisms of T cell adaptation using an experimental autoimmune encephalomyelitis (EAE) model in which the fate of autopathogenic T cells could be followed. We demonstrated that immunisation with a high dose of myelin basic protein (MBP) peptide and complete Freund's adjuvant failed to effectively initiate EAE, in contrast to low dose MBP peptide immunisation which readily induced disease. The proportion of autopathogenic CD4+ T cells in the central nervous system (CNS) of mice immunised with a high dose of MBP peptide was not significantly different to mice immunised with a low dose. However, autopathogenic T cells in mice immunised with high dose MBP peptide had an unresponsive phenotype in ex vivo recall assays. Importantly, whilst expression of PD‐1 was increased on adapted CD4+ T cells within the CNS, loss of PD‐1 function did not prevent the development of the unresponsive state. The lack of a role for PD‐1 in the acquisition of the adapted state stands in striking contrast to the reported functional importance of PD‐1 in T cell unresponsiveness in other disease models.
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Affiliation(s)
- Iris Mair
- MRC Centre for Inflammation Research, Centre for Multiple Sclerosis Research, Centre for Immunity, Infection and Evolution, The University of Edinburgh, Edinburgh, UK
| | - Dario Besusso
- MRC Centre for Inflammation Research, Centre for Multiple Sclerosis Research, Centre for Immunity, Infection and Evolution, The University of Edinburgh, Edinburgh, UK
| | - Louise Saul
- MRC Centre for Inflammation Research, Centre for Multiple Sclerosis Research, Centre for Immunity, Infection and Evolution, The University of Edinburgh, Edinburgh, UK
| | - Sarju D Patel
- MRC Centre for Inflammation Research, Centre for Multiple Sclerosis Research, Centre for Immunity, Infection and Evolution, The University of Edinburgh, Edinburgh, UK
| | - Rahul Ravindran
- MRC Centre for Inflammation Research, Centre for Multiple Sclerosis Research, Centre for Immunity, Infection and Evolution, The University of Edinburgh, Edinburgh, UK
| | - Rhoanne C McPherson
- MRC Centre for Inflammation Research, Centre for Multiple Sclerosis Research, Centre for Immunity, Infection and Evolution, The University of Edinburgh, Edinburgh, UK
| | - Melanie D Leech
- MRC Centre for Inflammation Research, Centre for Multiple Sclerosis Research, Centre for Immunity, Infection and Evolution, The University of Edinburgh, Edinburgh, UK
| | - Richard A O'Connor
- MRC Centre for Inflammation Research, Centre for Multiple Sclerosis Research, Centre for Immunity, Infection and Evolution, The University of Edinburgh, Edinburgh, UK
| | - Stephen M Anderton
- MRC Centre for Inflammation Research, Centre for Multiple Sclerosis Research, Centre for Immunity, Infection and Evolution, The University of Edinburgh, Edinburgh, UK
| | - Richard J Mellanby
- MRC Centre for Inflammation Research, Centre for Multiple Sclerosis Research, Centre for Immunity, Infection and Evolution, The University of Edinburgh, Edinburgh, UK.,The Royal (Dick) School of Veterinary Studies and The Roslin Institute, Division of Veterinary Clinical Studies, The University of Edinburgh, Hospital for Small Animals, Easter Bush Veterinary Centre, Roslin, Midlothian, UK
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Mair I, Zandee SEJ, Toor IS, Saul L, McPherson RC, Leech MD, Smyth DJ, O’Connor RA, Henderson NC, Anderton SM. A Context-Dependent Role for αv Integrins in Regulatory T Cell Accumulation at Sites of Inflammation. Front Immunol 2018; 9:264. [PMID: 29535709 PMCID: PMC5834440 DOI: 10.3389/fimmu.2018.00264] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 01/30/2018] [Indexed: 01/20/2023] Open
Abstract
Several inflammatory diseases including multiple sclerosis and inflammatory bowel disease have been associated with dysfunctional and/or reduced numbers of Foxp3+ regulatory T cells (Treg). While numerous mechanisms of action have been discovered by which Treg can exert their function, disease-specific Treg requirements remain largely unknown. We found that the integrin αv, which can pair with several β subunits including β8, is highly upregulated in Treg at sites of inflammation. Using mice that lacked αv expression or β8 expression specifically in Treg, we demonstrate that there was no deficit in Treg accumulation in the central nervous system during experimental autoimmune encephalomyelitis and no difference in the resolution of disease compared to control mice. In contrast, during a curative T cell transfer model of colitis, Treg lacking all αv integrins were found at reduced proportions and numbers in the inflamed gut. This led to a quantitative impairment in the ability of αv-deficient Treg to reverse disease when Treg numbers in the inflamed colon were below a threshold. Increase of the number of curative Treg injected was able to rescue this phenotype, indicating that αv integrins were not required for the immunosuppressive function of Treg per se. In accordance with this, αv deficiency did not impact on the capacity of Treg to suppress proliferation of naive conventional T cells in vitro as well as in vivo. These observations demonstrate that despite the general upregulation of αv integrins in Treg at sites of inflammation, they are relevant for adequate Treg accumulation only in specific disease settings. The understanding of disease-specific mechanisms of action by Treg has clear implications for Treg-targeted therapies.
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Affiliation(s)
- Iris Mair
- MRC Centre for Inflammation Research, Centre for Multiple Sclerosis Research, BHF Centre for Cardiovascular Science, and Centre for Immunity Infection and Evolution, University of Edinburgh, Edinburgh, United Kingdom
| | - Stephanie E. J. Zandee
- MRC Centre for Inflammation Research, Centre for Multiple Sclerosis Research, BHF Centre for Cardiovascular Science, and Centre for Immunity Infection and Evolution, University of Edinburgh, Edinburgh, United Kingdom
| | - Iqbal S. Toor
- MRC Centre for Inflammation Research, Centre for Multiple Sclerosis Research, BHF Centre for Cardiovascular Science, and Centre for Immunity Infection and Evolution, University of Edinburgh, Edinburgh, United Kingdom
| | - Louise Saul
- MRC Centre for Inflammation Research, Centre for Multiple Sclerosis Research, BHF Centre for Cardiovascular Science, and Centre for Immunity Infection and Evolution, University of Edinburgh, Edinburgh, United Kingdom
| | - Rhoanne C. McPherson
- MRC Centre for Inflammation Research, Centre for Multiple Sclerosis Research, BHF Centre for Cardiovascular Science, and Centre for Immunity Infection and Evolution, University of Edinburgh, Edinburgh, United Kingdom
| | - Melanie D. Leech
- MRC Centre for Inflammation Research, Centre for Multiple Sclerosis Research, BHF Centre for Cardiovascular Science, and Centre for Immunity Infection and Evolution, University of Edinburgh, Edinburgh, United Kingdom
| | - Danielle J. Smyth
- MRC Centre for Inflammation Research, Centre for Multiple Sclerosis Research, BHF Centre for Cardiovascular Science, and Centre for Immunity Infection and Evolution, University of Edinburgh, Edinburgh, United Kingdom
| | - Richard A. O’Connor
- MRC Centre for Inflammation Research, Centre for Multiple Sclerosis Research, BHF Centre for Cardiovascular Science, and Centre for Immunity Infection and Evolution, University of Edinburgh, Edinburgh, United Kingdom
| | - Neil C. Henderson
- MRC Centre for Inflammation Research, Centre for Multiple Sclerosis Research, BHF Centre for Cardiovascular Science, and Centre for Immunity Infection and Evolution, University of Edinburgh, Edinburgh, United Kingdom
| | - Stephen M. Anderton
- MRC Centre for Inflammation Research, Centre for Multiple Sclerosis Research, BHF Centre for Cardiovascular Science, and Centre for Immunity Infection and Evolution, University of Edinburgh, Edinburgh, United Kingdom
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Besusso D, Saul L, Leech MD, O'Connor RA, MacDonald AS, Anderton SM, Mellanby RJ. 1,25-Dihydroxyvitamin D3-Conditioned CD11c+ Dendritic Cells are Effective Initiators of CNS Autoimmune Disease. Front Immunol 2015; 6:575. [PMID: 26635791 PMCID: PMC4650204 DOI: 10.3389/fimmu.2015.00575] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 10/26/2015] [Indexed: 11/14/2022] Open
Abstract
Dendritic cells (DC) play a crucial role in regulating T cell activation. Due to their capacity to shape the immune response, tolerogenic DC have been used to treat autoimmune diseases. In this study, we examined whether 1,25 dihydroxyvitamin D3-conditioned bone marrow-derived DC (VitD-BMDC) were able to limit the development of autoimmune pathology in experimental autoimmune encephalomyelitis (EAE). We found that VitD-BMDC had lower expression of MHC class II and co-stimulatory molecules and were less effective at priming autoreactive T cells in vitro. Using our recently described BMDC-driven model of EAE, we demonstrated that VitD-BMDC had a significantly reduced ability to initiate EAE. We found that the impaired ability of VitD-BMDC to initiate EAE was not due to T cell tolerization. Instead, we discovered that the addition of 1,25(OH)2D3 to BMDC cultures resulted in a significant reduction in the proportion of CD11c+ cells. Purified CD11c+ VitD-BMDC were significantly less effective at priming T cells in vitro yet were similarly capable of initiating EAE as vehicle-treated CD11c+ BMDC. This study demonstrates that in vitro assays of DC function can be a poor predictor of in vivo behavior and that CD11c+ VitD-BMDC are highly effective initiators of an autopathogenic T cell response.
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Affiliation(s)
- Dario Besusso
- MRC Centre for Inflammation Research, The University of Edinburgh , Edinburgh , UK ; Centre for Multiple Sclerosis Research, The University of Edinburgh , Edinburgh , UK ; Centre for Immunity, Infection and Evolution, The University of Edinburgh , Edinburgh , UK
| | - Louise Saul
- MRC Centre for Inflammation Research, The University of Edinburgh , Edinburgh , UK ; Centre for Multiple Sclerosis Research, The University of Edinburgh , Edinburgh , UK ; Centre for Immunity, Infection and Evolution, The University of Edinburgh , Edinburgh , UK
| | - Melanie D Leech
- MRC Centre for Inflammation Research, The University of Edinburgh , Edinburgh , UK ; Centre for Multiple Sclerosis Research, The University of Edinburgh , Edinburgh , UK ; Centre for Immunity, Infection and Evolution, The University of Edinburgh , Edinburgh , UK
| | - Richard A O'Connor
- MRC Centre for Inflammation Research, The University of Edinburgh , Edinburgh , UK ; Centre for Multiple Sclerosis Research, The University of Edinburgh , Edinburgh , UK ; Centre for Immunity, Infection and Evolution, The University of Edinburgh , Edinburgh , UK
| | - Andrew S MacDonald
- Manchester Collaborative Centre for Inflammation Research, The University of Manchester , Manchester , UK
| | - Stephen M Anderton
- MRC Centre for Inflammation Research, The University of Edinburgh , Edinburgh , UK ; Centre for Multiple Sclerosis Research, The University of Edinburgh , Edinburgh , UK ; Centre for Immunity, Infection and Evolution, The University of Edinburgh , Edinburgh , UK
| | - Richard J Mellanby
- MRC Centre for Inflammation Research, The University of Edinburgh , Edinburgh , UK ; Centre for Multiple Sclerosis Research, The University of Edinburgh , Edinburgh , UK ; Centre for Immunity, Infection and Evolution, The University of Edinburgh , Edinburgh , UK ; The Roslin Institute, Royal (Dick) School of Veterinary Studies, The University of Edinburgh , Midlothian , UK
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Turner DG, Leech MD, O'Connor RA, Anderton SM. Methods for Ex Vivo Analysis of Immune Cell Function from the Central Nervous System. Methods Mol Biol 2015; 1304:81-90. [PMID: 25863784 DOI: 10.1007/7651_2015_222] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Experimental autoimmune encephalomyelitis (EAE) is an animal model commonly used to investigate the inflammatory response in organ-specific autoimmunity and a model of the early immune responses of multiple sclerosis.This protocol outlines the methods used for the processing of peripheral immune tissues, the spleen and draining lymph nodes, as well as the site of inflammation, the central nervous system (CNS), for analyzing immune cell phenotype and function during murine EAE.
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Affiliation(s)
- Darryl G Turner
- MRC Centre for Inflammation Research, Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh, EH16 4TJ, UK
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McPherson RC, Konkel JE, Prendergast CT, Thomson JP, Ottaviano R, Leech MD, Kay O, Zandee SEJ, Sweenie CH, Wraith DC, Meehan RR, Drake AJ, Anderton SM. Epigenetic modification of the PD-1 (Pdcd1) promoter in effector CD4(+) T cells tolerized by peptide immunotherapy. eLife 2014; 3. [PMID: 25546306 PMCID: PMC4297948 DOI: 10.7554/elife.03416] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 12/24/2014] [Indexed: 12/14/2022] Open
Abstract
Clinically effective antigen-based immunotherapy must silence antigen-experienced effector T cells (Teff) driving ongoing immune pathology. Using CD4+ autoimmune Teff cells, we demonstrate that peptide immunotherapy (PIT) is strictly dependent upon sustained T cell expression of the co-inhibitory molecule PD-1. We found high levels of 5-hydroxymethylcytosine (5hmC) at the PD-1 (Pdcd1) promoter of non-tolerant T cells. 5hmC was lost in response to PIT, with DNA hypomethylation of the promoter. We identified dynamic changes in expression of the genes encoding the Ten-Eleven-Translocation (TET) proteins that are associated with the oxidative conversion 5-methylcytosine and 5hmC, during cytosine demethylation. We describe a model whereby promoter demethylation requires the co-incident expression of permissive histone modifications at the Pdcd1 promoter together with TET availability. This combination was only seen in tolerant Teff cells following PIT, but not in Teff that transiently express PD-1. Epigenetic changes at the Pdcd1 locus therefore determine the tolerizing potential of TCR-ligation. DOI:http://dx.doi.org/10.7554/eLife.03416.001 The immune system protects the body from dangerous microbes and removes damaged cells. However, in some cases, the immune system can malfunction and attack healthy tissues, which can lead to type-1 diabetes, multiple sclerosis, and other autoimmune diseases. Many of the current treatments for these disorders suppress the immune system, which can make the individuals more susceptible to infections. It may be possible to treat autoimmune diseases using small pieces of protein—called peptides—that are based on proteins found on the cells that the immune system attacks by mistake. This strategy would target the specific immune cells that are malfunctioning, but allow the rest of the immune system to continue to work as normal. Peptide-based therapies for autoimmune diseases are currently being tested in clinical trials, and although the results look promising, it is not known precisely how they work. McPherson et al. used mice that develop a disease similar to multiple sclerosis because some of their immune cells, known as effector T cells, attack a protein found in the mouse brain called MBP. The mice were treated with a peptide based on part of MBP, which prevented them from developing the autoimmune disease. The success of the peptide therapy depended on the T cells producing large amounts of a protein called PD-1. This protein stops the T-cells from activating immune responses when they detect the MBP protein. The gene that makes PD-1 can have a methyl-tag—a chemical modification to DNA—which alters how much PD-1 is made in the T cells. When the gene has this methyl-tag, it can only be switched on for a short time to make a small amount of PD-1, which helps to control the immune responses activated by the T cell. However, when the methyl-tag was removed as a result of the peptide therapy the gene could be switched on for much longer, so that much more PD-1 was produced. This work helps us to understand how peptide therapy works and should improve the chances of using this therapy to successfully treat patients with autoimmune diseases. DOI:http://dx.doi.org/10.7554/eLife.03416.002
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Affiliation(s)
- Rhoanne C McPherson
- MRC Centre for Inflammation Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Joanne E Konkel
- MRC Centre for Inflammation Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Catriona T Prendergast
- MRC Centre for Inflammation Research, University of Edinburgh, Edinburgh, United Kingdom
| | - John P Thomson
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Raffaele Ottaviano
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Melanie D Leech
- MRC Centre for Inflammation Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Oliver Kay
- MRC Centre for Inflammation Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Stephanie E J Zandee
- MRC Centre for Inflammation Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Claire H Sweenie
- MRC Centre for Inflammation Research, University of Edinburgh, Edinburgh, United Kingdom
| | - David C Wraith
- Department of Cellular and Molecular Medicine, University of Bristol, Bristol, United Kingdom
| | - Richard R Meehan
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Amanda J Drake
- University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, United Kingdom
| | - Stephen M Anderton
- MRC Centre for Inflammation Research, University of Edinburgh, Edinburgh, United Kingdom
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Mackenzie KJ, Fitch PM, Leech MD, Ilchmann A, Wilson C, McFarlane AJ, Howie SEM, Anderton SM, Schwarze J. Combination peptide immunotherapy based on T-cell epitope mapping reduces allergen-specific IgE and eosinophilia in allergic airway inflammation. Immunology 2013; 138:258-68. [PMID: 23113712 DOI: 10.1111/imm.12032] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2012] [Revised: 10/16/2012] [Accepted: 10/22/2012] [Indexed: 01/04/2023] Open
Abstract
Peptide immunotherapy using soluble peptides containing allergen-derived immunodominant T-cell epitopes holds therapeutic promise for allergic asthma. Previous studies in BALB/c mice using the immunodominant peptide epitope of chicken ovalbumin (p323-339) have been unable to demonstrate therapeutic effects in ovalbumin-induced allergic airway inflammation. We have previously shown that intravenous application of p323-339 can effectively tolerise p323-339-reactive T cells in a non-allergic model in C57BL/6 mice. This study aimed to assess the effects of using p323-339 immunotherapy in a C57BL/6 model of ovalbumin-induced allergic airway inflammation, identify any additional epitopes recognized by the ovalbumin-responsive T-cell repertoire in C57BL/6 mice and assess the effects of combination peptide immunotherapy in this model. Ovalbumin-reactive T-cell lines were generated from ovalbumin-immunized C57BL/6 mice and proliferative responses to a panel of overlapping peptides covering the ovalbumin sequence were assessed. Soluble peptides (singly or combined) were administered intravenously to C57BL/6 mice before the induction of ovalbumin-induced allergic airway inflammation. Peptide immunotherapy using the 323-339 peptide alone did not reduce the severity of allergic airway inflammation. An additional immunodominant T-cell epitope in ovalbumin was identified within the 263-278 sequence. Combination peptide immunotherapy, using the 323-339 and 263-278 peptides together, reduced eosinophilia in the bronchoalveolar lavage and ovalbumin-specific IgE, with apparent reductions in interleukin-5 and interleukin-13. Characterization of the T-cell response to a model allergen has allowed the development of combination peptide immunotherapy with improved efficacy in allergic airway inflammation. This model holds important potential for future mechanistic studies using peptide immunotherapy in allergy.
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Affiliation(s)
- Karen J Mackenzie
- MRC Centre for Inflammation Research, University of Edinburgh, Edinburgh, UK
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Leech MD, Barr TA, Turner DG, Brown S, O'Connor RA, Gray D, Mellanby RJ, Anderton SM. Cutting edge: IL-6-dependent autoimmune disease: dendritic cells as a sufficient, but transient, source. J Immunol 2012; 190:881-5. [PMID: 23267024 DOI: 10.4049/jimmunol.1202925] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Mice lacking IL-6 are resistant to autoimmune diseases, such as experimental autoimmune encephalomyelitis (EAE), which is driven by CNS-reactive CD4(+) T cells. There are multiple cellular sources of IL-6, but the critical source in EAE has been uncertain. Using cell-specific IL-6 deficiency in models of EAE induced by active immunization, passive transfer, T cell transfer, and dendritic cell transfer, we show that neither the pathogenic T cells nor CNS-resident cells are required to produce IL-6. Instead, the requirement for IL-6 was restricted to the early stages of T cell activation and was entirely controlled by dendritic cell-derived IL-6. This reflected the loss of IL-6R expression by T cells over time. These data explain why blockade of IL-6R only achieves protection against EAE if used at the time of T cell priming. The implications for therapeutic manipulation of IL-6 signaling in human T cell-driven autoimmune conditions are considered.
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Affiliation(s)
- Melanie D Leech
- Medical Research Council Centre for Inflammation Research, Centre for Multiple Sclerosis Research and Centre for Immunity, Infection, and Evolution, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
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Mellanby RJ, Cambrook H, Turner DG, O'Connor RA, Leech MD, Kurschus FC, MacDonald AS, Arnold B, Anderton SM. TLR-4 ligation of dendritic cells is sufficient to drive pathogenic T cell function in experimental autoimmune encephalomyelitis. J Neuroinflammation 2012; 9:248. [PMID: 23111144 PMCID: PMC3520704 DOI: 10.1186/1742-2094-9-248] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Accepted: 10/10/2012] [Indexed: 01/09/2023] Open
Abstract
Background Experimental autoimmune encephalomyelitis (EAE) depends on the initial activation of CD4+ T cells responsive to myelin autoantigens. The key antigen presenting cell (APC) population that drives the activation of naïve T cells most efficiently is the dendritic cell (DC). As such, we should be able to trigger EAE by transfer of DC that can present the relevant autoantigen(s). Despite some sporadic reports, however, models of DC-driven EAE have not been widely adopted. We sought to test the feasibility of this approach and whether activation of the DC by toll-like receptor (TLR)-4 ligation was a sufficient stimulus to drive EAE. Findings Host mice were seeded with myelin basic protein (MBP)-reactive CD4+ T cells and then were injected with DC that could present the relevant MBP peptide which had been exposed to lipopolysaccharide as a TLR-4 agonist. We found that this approach induced robust clinical signs of EAE. Conclusions DC are sufficient as APC to effectively drive the differentiation of naïve myelin-responsive T cells into autoaggressive effector T cells. TLR-4-stimulation can activate the DC sufficiently to deliver the signals required to drive the pathogenic function of the T cell. These models will allow the dissection of the molecular requirements of the initial DC-T cell interaction in the lymphoid organs that ultimately leads to autoimmune pathology in the central nervous system.
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Affiliation(s)
- Richard J Mellanby
- Medical Research Council/University of Edinburgh Centre for Inflammation Research, Centre for Multiple Sclerosis Research and Centre for Immunity Infection and Evolution, Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, UK
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Leech MD, Carrillo-Vico A, Liblau RS, Anderton SM. Recognition of a high affinity MHC class I-restricted epitope of myelin oligodendrocyte glycoprotein by CD8⁺ T cells derived from autoantigen-deficient mice. Front Immunol 2011; 2:17. [PMID: 22566807 PMCID: PMC3342349 DOI: 10.3389/fimmu.2011.00017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Accepted: 05/13/2011] [Indexed: 01/06/2023] Open
Abstract
CD4⁺ T cells have a well-defined pathogenic role in experimental autoimmune encephalomyelitis, the rodent model of multiple sclerosis (MS), yet CD8⁺ T cells are commonly found in MS lesions. To determine whether immunological tolerance might impact differently on CD4⁺ versus CD8⁺ T cells, we studied T cell responses in mice genetically deficient for the central nervous system (CNS) autoantigen myelin oligodendrocyte glycoprotein (MOG) versus wild type (WT) C57BL/6 mice. We show that MOG(-/-) mice have enhanced sensitivity to immunization with the immunodominant peptide of MOG (35-55), as evidenced by increased expansion of both CD4⁺ and CD8⁺ T cell subsets. Most strikingly, CD8⁺ T cells from MOG(-/-) mice responded to a novel T cell epitope which binds to MHC class I with high affinity. Despite this, MOG-responsive CD8⁺ T cells sourced from either WT or MOG(-/-) mice failed to initiate CNS inflammation upon transfer to MOG-sufficient mice. In our hands, this capacity was only found in CD4⁺ T cells. However, MOG(-/-) CD4⁺ cells did not show greater pathogenic activity than their WT counterparts. Our data indicate that, in the presence of endogenous MOG, CD8⁺ T cells capable of responding to a MHC class I-restricted epitope that can be stably expressed are subject to rigorous control through central and/or peripheral tolerance.
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Affiliation(s)
- Melanie D Leech
- Centre for Inflammation Research, Centre for Multiple Sclerosis Research and Centre for Immunity, Infection and Evolution, Queen's Medical Research Institute, University of Edinburgh Edinburgh, UK
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O'Connor RA, Leech MD, Suffner J, Hämmerling GJ, Anderton SM. Myelin-reactive, TGF-β-induced regulatory T cells can be programmed to develop Th1-like effector function but remain less proinflammatory than myelin-reactive Th1 effectors and can suppress pathogenic T cell clonal expansion in vivo. J Immunol 2010; 185:7235-43. [PMID: 21084662 DOI: 10.4049/jimmunol.1001551] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Interest in the use of regulatory T cells (Tregs) as cellular therapeutics has been tempered by reports of naturally occurring Tregs losing Foxp3 expression and producing IL-17, raising concerns over a switch to pathogenic function under inflammatory conditions in vivo. TGF-β-induced Tregs (inducible Tregs [iTregs]), generated in large numbers in response to disease-relevant Ags, represent the most amenable source of therapeutic Tregs. Using Foxp3-reporter T cells recognizing myelin basic protein (MBP), we investigated the capacity of iTregs to produce effector-associated cytokines under proinflammatory cytokine conditions in vitro and whether this translated into proinflammatory function in vivo. In contrast with naturally occurring Tregs, iTregs resisted conversion to an IL-17-producing phenotype but were able to express T-bet and to produce IFN-γ. iTregs initiated their T-bet expression during their in vitro induction, and this was dependent on exposure to IFN-γ. IL-12 reignited iTreg expression of T-bet and further promoted iTreg production of IFN-γ upon secondary stimulation. Despite losing Foxp3 expression and expressing both T-bet and IFN-γ, MBP-responsive IL-12-conditioned iTregs induced only mild CNS inflammation and only when given in high numbers. Furthermore, iTregs retained an ability to suppress naive T cell clonal expansion in vivo and protected against the development of experimental autoimmune encephalomyelitis. Therefore, despite bearing predictive hallmarks of pathogenic effector function, previously Foxp3(+) iTregs have much lower proinflammatory potential than that of MBP-responsive Th1 cells. Our results demonstrate that autoprotective versus autoaggressive functions in iTregs are not simply a binary relationship to be determined by their relative expression of Foxp3 versus T-bet and IFN-γ.
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Affiliation(s)
- Richard A O'Connor
- Medical Research Council, Centre for Inflammation Research, University of Edinburgh, Queen's Medical Research Institute, Edinburgh EH16 4TJ, United Kingdom
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Carrillo-Vico A, Leech MD, Anderton SM. Contribution of myelin autoantigen citrullination to T cell autoaggression in the central nervous system. J Immunol 2010; 184:2839-46. [PMID: 20164413 DOI: 10.4049/jimmunol.0903639] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Breakdown in immunological self tolerance, leading to autoimmune diseases such as multiple sclerosis, might arise from immune recognition of self proteins that have undergone heightened posttranslational modification under pathophysiological conditions. A posttranslational modification of particular interest is the deimination of Arg to citrulline, catalyzed by peptidylarginyl deiminase (PAD) enzymes. As a CD4(+) T cell-driven model of multiple sclerosis, we used experimental autoimmune encephalomyelitis (EAE) induced with the immunodominant 35-55 peptide of myelin oligodendrocyte glycoprotein (pMOG) in C57BL/6 mice to test whether citrullination of a T cell epitope can contribute to disease etiopathology. Immunization with an altered peptide ligand (APL) of pMOG with an Arg-->citrulline conversion at a TCR contact (residue 41) led to the activation of two populations of APL-responsive T cells that either did, or did not cross-react with the native pMOG peptide. This APL could induce EAE. However, this reflected the activation of T cells that cross-reacted with the native pMOG epitope, because prior tolerization of these T cells using pMOG prevented APL-induced EAE. Using a passive transfer model, we found that T cells that responded specifically to the citrullinated form of pMOG were neither necessary, nor sufficient to initiate the EAE lesion. Nevertheless, these cells could provoke exacerbation of pathology if transferred into mice with ongoing EAE. The PAD2 and PAD4 enzymes were markedly upregulated in the inflamed CNS. Therefore, once inflammation is established, citrullination of target autoantigens can allow an expanded repertoire of T cells to contribute to CNS pathology.
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Affiliation(s)
- Antonio Carrillo-Vico
- Centre for Inflammation Research, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom
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Konkel JE, Frommer F, Leech MD, Yagita H, Waisman A, Anderton SM. PD-1 signalling in CD4(+) T cells restrains their clonal expansion to an immunogenic stimulus, but is not critically required for peptide-induced tolerance. Immunology 2010; 130:92-102. [PMID: 20113370 DOI: 10.1111/j.1365-2567.2009.03216.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The ultimate outcome of T-cell recognition of peptide-major histocompatibility complex (MHC) complexes is determined by the molecular context in which antigen presentation is provided. The paradigm is that, after exposure to peptides presented by steady-state dendritic cells (DCs), inhibitory signals dominate, leading to the deletion and/or functional inactivation of antigen-reactive T cells. This has been utilized in a variety of models providing peptide antigen in soluble form in the absence of adjuvant. A co-inhibitory molecule of considerable current interest is PD-1. Here we show that there is the opportunity for the PD-1/PD-L1 interaction to function in inhibiting the T-cell response during tolerance induction. Using traceable CD4(+) T-cell receptor (TCR) transgenic cells, together with a blocking antibody to disrupt PD-1 signalling, we explored the roles of PD-1 in the induction of tolerance versus a productive immune response. Intact PD-1 signalling played a role in limiting the extent of CD4(+) T-cell accumulation in response to an immunogenic stimulus. However, PD-1 signalling was not required for either the induction, or the maintenance, of peptide-induced tolerance; a conclusion underlined by successful tolerance induction in TCR transgenic cells genetically deficient for PD-1. These observations contrast with the reported requirement for PD-1 signals in CD8(+) T-cell tolerance.
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Affiliation(s)
- Joanne E Konkel
- Centre for Immunity Infection and Evolution, Institute of Immunology and Infection Research, Ashworth Laboratories, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
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O'Connor RA, Prendergast CT, Sabatos CA, Lau CWZ, Leech MD, Wraith DC, Anderton SM. Cutting edge: Th1 cells facilitate the entry of Th17 cells to the central nervous system during experimental autoimmune encephalomyelitis. J Immunol 2008; 181:3750-4. [PMID: 18768826 DOI: 10.4049/jimmunol.181.6.3750] [Citation(s) in RCA: 243] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
It has recently been proposed that experimental autoimmune encephalomyelitis, once considered the classical Th1 disease, is predominantly Th17 driven. In this study we show that myelin-reactive Th1 preparations devoid of contaminating IL-17(+) cells are highly pathogenic. In contrast, Th17 preparations lacking IFN-gamma(+) cells do not cause disease. Our key observation is that only Th1 cells can access the noninflamed CNS. Once Th1 cells establish the experimental autoimmune encephalomyelitis lesion, Th17 cells appear in the CNS. These data shed important new light on the ability of Th1 vs Th17 cells to access inflamed vs normal tissue. Because the IL-17-triggered release of chemokines by stromal cells could attract many other immune cells, allowing Th17 cells to access the tissues only under conditions of inflammation may be a key process limiting (auto)immune pathology. This has major implications for the design of therapeutic interventions, many of which are now aiming at Th17 rather than Th1 cells.
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Affiliation(s)
- Richard A O'Connor
- University of Edinburgh, Institute of Immunology and Infection Research, School of Biological Sciences, Edinburgh, United Kingdom
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Abstract
Administration of peptide antigens in tolerogenic form holds promise as a specific treatment for autoimmune and allergic disorders. However, experiments in rodent autoimmune models have highlighted the risk of anaphylaxis in response to systemic peptide application once the aberrant immune response is underway. Thus, mice with clinical signs of experimental autoimmune encephalomyelitis (EAE) or diabetes have been reported to suffer fatal anaphylaxis upon administration of native autoantigenic peptides. Clearly, this might represent a significant barrier to the use of synthetic peptides in the treatment of ongoing human autoimmune conditions. Here we describe the development of an altered peptide ligand (APL) engineered to prevent anaphylaxis (no antibody binding) whilst retaining the ability to silence pathogenic myelin-reactive T lymphocytes. Administration of the APL to mice with an ongoing anti-myelin immune response did not cause anaphylaxis, but led to complete protection from the subsequent induction of EAE and, when given during ongoing EAE, led to a rapid remission of clinical signs. The approach of removing antibody recognition whilst maintaining the desired functional effect (in this case T cell tolerance) may be of value in other situations in which there is a risk of triggering anaphylaxis with peptide-based drugs.
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Affiliation(s)
- Melanie D Leech
- University of Edinburgh, Institute of Immunology and Infection Research, School of Biological Sciences, Edinburgh, UK
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Leech MD, Benson RA, De Vries A, Fitch PM, Howie SEM. Resolution of Der p1-induced allergic airway inflammation is dependent on CD4+CD25+Foxp3+ regulatory cells. J Immunol 2007; 179:7050-8. [PMID: 17982096 DOI: 10.4049/jimmunol.179.10.7050] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Allergic airway inflammation (AAI) is characterized by airway hyperreactivity, eosinophilia, goblet cell hyperplasia, and elevated serum IgE, however, it is unclear what mediates natural resolution after cessation of allergen exposure. This is important because the outcome of subsequent allergen challenge may depend on the concurrent inflammatory milieu of the lung. Using a murine AAI model, we demonstrate that after exposure to a defined natural protein allergen, Der p1, the response in lungs and draining mediastinal lymph nodes (dMLN) peaks between 4 and 6 days then declines until resolution by 21 days. Der p1-specific serum IgE follows the same pattern while IgG1 continues to increase. Resolution of AAI is mediated by CD4(+)CD25(+)Foxp3(+) regulatory T cells (Tregs), which appear in lungs and dMLN following airway challenge. Treg depletion exacerbated lung eosinophilia, increased dMLN IL-5 and IL-13 but not IL-10 secretion, and increased allergic Ab responses. Most convincingly, transfer of CD4(+)CD25(+)Foxp3(+) T cells from Ag naive mice (natural Tregs) abolished AAI, decreased dMLN IL-5 and IL-13 secretion, increased dMLN IL-10 secretion, abolished IgE, and decreased IgG1 Abs. Blocking IL-10 receptor function in vivo did not block the anti-inflammatory function of transferred natural Tregs but did restore dMLN IL-5 and IL-13 secretion. Thus natural Tregs can control AAI in an IL-10 independent manner.
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Affiliation(s)
- Melanie D Leech
- Immunobiology Group, Medical Research Council Centre for Inflammation Research, University of Edinburgh, Queen's Medical Research Institute, Edinburgh, United Kingdom
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Abstract
Dendritic cells can be considered natural adjuvants and are able to act as cellular vaccines to protect against disease. Adoptive transfer of Ag-pulsed bone marrow-derived dendritic cells (BMDCs) enhanced expulsion of the intestinal nematode, Trichinella spiralis, from the small intestine. IL 9 is a critical cytokine in protective immunity to intestinal nematode infection and is believed to enhance Th2 immune responses. Deriving dendritic cells from an IL-9 transgenic (IL-9t) mouse has enabled a detailed investigation of the importance of IL-9 during Ag presentation. Indeed, IL-9t dendritic cells significantly enhanced T cell proliferation and Th2 responses and, after adoptive transfer, enhanced parasite-specific IgG1 and intestinal mastocytosis in vivo, leading to accelerated expulsion of adult worms from the intestine. Overall, this paper demonstrates that dendritic cell vaccination can be used to successfully protect the host against intestinal nematode infection and suggests that IL-9 can act as a potent type 2 adjuvant during Ag presentation and the early stages of Th2 activation.
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