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Johnson MB, Ogishi M, Domingo-Vila C, De Franco E, Wakeling MN, Imane Z, Resnick B, Williams E, Galão RP, Caswell R, Russ-Silsby J, Seeleuthner Y, Rinchai D, Fagniez I, Benson B, Dufort MJ, Speake C, Smithmyer ME, Hudson M, Dobbs R, Quandt Z, Hattersley AT, Zhang P, Boisson-Dupuis S, Anderson MS, Casanova JL, Tree TI, Oram RA. Human inherited PD-L1 deficiency is clinically and immunologically less severe than PD-1 deficiency. J Exp Med 2024; 221:e20231704. [PMID: 38634869 PMCID: PMC11032109 DOI: 10.1084/jem.20231704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 01/16/2024] [Accepted: 03/13/2024] [Indexed: 04/19/2024] Open
Abstract
We previously reported two siblings with inherited PD-1 deficiency who died from autoimmune pneumonitis at 3 and 11 years of age after developing other autoimmune manifestations, including type 1 diabetes (T1D). We report here two siblings, aged 10 and 11 years, with neonatal-onset T1D (diagnosed at the ages of 1 day and 7 wk), who are homozygous for a splice-site variant of CD274 (encoding PD-L1). This variant results in the exclusive expression of an alternative, loss-of-function PD-L1 protein isoform in overexpression experiments and in the patients' primary leukocytes. Surprisingly, cytometric immunophenotyping and single-cell RNA sequencing analysis on blood leukocytes showed largely normal development and transcriptional profiles across lymphoid and myeloid subsets in the PD-L1-deficient siblings, contrasting with the extensive dysregulation of both lymphoid and myeloid leukocyte compartments in PD-1 deficiency. Our findings suggest that PD-1 and PD-L1 are essential for preventing early-onset T1D but that, unlike PD-1 deficiency, PD-L1 deficiency does not lead to fatal autoimmunity with extensive leukocytic dysregulation.
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Affiliation(s)
- Matthew B. Johnson
- Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
| | - Masato Ogishi
- St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, NY, USA
| | - Clara Domingo-Vila
- Department of Immunobiology, School of Immunology and Microbial Sciences, Kings College London, London, UK
| | - Elisa De Franco
- Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
| | - Matthew N. Wakeling
- Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
| | - Zineb Imane
- Faculty of Medicine and Pharmacy, Mohammed 5 University of Rabat, Rabat, Morocco
| | - Brittany Resnick
- National Institute for Health and Care Research Exeter Clinical Research Facility, Royal Devon University Healthcare NHS Foundation Trust, Exeter, UK
| | - Evangelia Williams
- Department of Immunobiology, School of Immunology and Microbial Sciences, Kings College London, London, UK
| | - Rui Pedro Galão
- Department of Infectious Diseases, School of Immunobiology and Microbial Sciences, Kings College London, London, UK
| | - Richard Caswell
- Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
| | - James Russ-Silsby
- Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
| | - Yoann Seeleuthner
- Laboratory of Human Genetics of Infectious Diseases, Necker Branch, INSERM U1163, Paris, France
- Imagine Institute, Paris Cité University, Paris, France
| | - Darawan Rinchai
- St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, NY, USA
| | - Iris Fagniez
- St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, NY, USA
| | - Basilin Benson
- Center for Systems Immunology, Benaroya Research Institute, Seattle, WA, USA
| | - Matthew J. Dufort
- Center for Systems Immunology, Benaroya Research Institute, Seattle, WA, USA
| | - Cate Speake
- Center for Interventional Immunology, Benaroya Research Institute, Seattle, WA, USA
| | - Megan E. Smithmyer
- Center for Interventional Immunology, Benaroya Research Institute, Seattle, WA, USA
| | - Michelle Hudson
- Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
- National Institute for Health and Care Research Exeter Clinical Research Facility, Royal Devon University Healthcare NHS Foundation Trust, Exeter, UK
| | - Rebecca Dobbs
- Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
- National Institute for Health and Care Research Exeter Clinical Research Facility, Royal Devon University Healthcare NHS Foundation Trust, Exeter, UK
| | - Zoe Quandt
- Endocrine Division, Department of Medicine, University of California San Francisco, San Francisco, CA, USA
- Diabetes Center, University of California San Francisco, San Francisco, CA, USA
| | - Andrew T. Hattersley
- Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
| | - Peng Zhang
- St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, NY, USA
| | - Stephanie Boisson-Dupuis
- St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, NY, USA
- Laboratory of Human Genetics of Infectious Diseases, Necker Branch, INSERM U1163, Paris, France
- Imagine Institute, Paris Cité University, Paris, France
| | - Mark S. Anderson
- Endocrine Division, Department of Medicine, University of California San Francisco, San Francisco, CA, USA
- Diabetes Center, University of California San Francisco, San Francisco, CA, USA
| | - Jean-Laurent Casanova
- St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, NY, USA
- Laboratory of Human Genetics of Infectious Diseases, Necker Branch, INSERM U1163, Paris, France
- Imagine Institute, Paris Cité University, Paris, France
- Department of Pediatrics, Necker Hospital for Sick Children, Paris, France
- Howard Hughes Medical Institute, New York, NY, USA
| | - Timothy I. Tree
- Department of Immunobiology, School of Immunology and Microbial Sciences, Kings College London, London, UK
| | - Richard A. Oram
- Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
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2
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Battaglia M, Buckner JH, Levings MK, Richardson SJ, Wong FS, Tree TI. Identifying the 'Achilles heel' of type 1 diabetes. Clin Exp Immunol 2021; 204:167-178. [PMID: 33368173 DOI: 10.1111/cei.13570] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 11/16/2020] [Accepted: 11/18/2020] [Indexed: 12/22/2022] Open
Abstract
When Thetis dipped her son Achilles into the River Styx to make him immortal, she held him by the heel, which was not submerged, and thus created a weak spot that proved deadly for Achilles. Millennia later, Achilles heel is part of today's lexicon meaning an area of weakness or a vulnerable spot that causes failure. Also implied is that an Achilles heel is often missed, forgotten or under-appreciated until it is under attack, and then failure is fatal. Paris killed Achilles with an arrow 'guided by the Gods'. Understanding the pathogenesis of type 1 diabetes (T1D) in order to direct therapy for prevention and treatment is a major goal of research into T1D. At the International Congress of the Immunology of Diabetes Society, 2018, five leading experts were asked to present the case for a particular cell/element that could represent 'the Achilles heel of T1D'. These included neutrophils, B cells, CD8+ T cells, regulatory CD4+ T cells, and enteroviruses, all of which have been proposed to play an important role in the pathogenesis of type 1 diabetes. Did a single entity emerge as 'the' Achilles heel of T1D? The arguments are summarized here, to make this case.
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Affiliation(s)
- M Battaglia
- San Raffaele Diabetes Research Institute, IRCCS San Raffaele Hospital, Milan, Italy
| | - J H Buckner
- Translational Research Program, Benaroya Research Institute at Virginia Mason, Seattle, WA, USA
| | - M K Levings
- BC Children's Hospital Research Institute, Vancouver, BC, Canada
| | - S J Richardson
- Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, UK
| | - F S Wong
- Division of Infection and Immunity, Cardiff University School of Medicine, Cardiff, UK
| | - T I Tree
- Department of Immunobiology, School of Immunology and Microbial Sciences (SIMS), King's College London, London, UK.,NIHR Biomedical Research Centre, Guy's and St Thomas' NHS Foundation Trust and King's College London, London, UK
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3
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Abstract
In recent years, there have been exciting new insights into pathogenesis of type 1 diabetes in a number of areas of immunology. In this edition, a collection of four review articles are presented, which encompass new findings presented at the Immunology of Diabetes Society meeting in London 2018. The articles are focused particularly in 4 related areas of investigation, which include autoantibodies in type 1 diabetes, new autoantigenic targets for CD4 T cells, trafficking of immune cells to the pancreas and islet‐immune interactions in the pancreas.
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Affiliation(s)
- F S Wong
- Division of Infection and Immunity, Cardiff University School of Medicine, Cardiff, UK
| | - T I Tree
- Programme of Infection and Immunity, Department of Immunobiology, Faculty of Life Sciences and Medicine, King's College London, Borough Wing, Guy's Hospital, London, UK
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4
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Mannering SI, Wong FS, Durinovic-Belló I, Brooks-Worrell B, Tree TI, Cilio CM, Schloot NC, Mallone R. Current approaches to measuring human islet-antigen specific T cell function in type 1 diabetes. Clin Exp Immunol 2010; 162:197-209. [PMID: 20846160 DOI: 10.1111/j.1365-2249.2010.04237.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Type 1 diabetes (T1D) is an autoimmune disease caused by the T cell-mediated destruction of the pancreatic insulin-producing beta cells. Currently there are no widely accepted and standardized assays available to analyse the function of autoreactive T cells involved in T1D. The development of such an assay would greatly aid efforts to understand the pathogenesis of T1D and is also urgently required to guide the development of antigen-based therapies intended to prevent, or cure, T1D. Here we describe some of the assays used currently to detect autoreactive T cells in human blood and review critically their strengths and weaknesses. The challenges and future prospects for the T cell assays are discussed.
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Affiliation(s)
- S I Mannering
- St Vincent's Institute, The University of Melbourne, Department of Medicine, St Vincent's Hospital, Fitzroy, Vic, Australia.
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5
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Moss CX, Tree TI, Watts C. Reconstruction of a pathway of antigen processing and class II MHC peptide capture. EMBO J 2007; 26:2137-47. [PMID: 17396153 PMCID: PMC1852786 DOI: 10.1038/sj.emboj.7601660] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2006] [Accepted: 02/26/2007] [Indexed: 11/10/2022] Open
Abstract
Endocytosed antigens are proteolytically processed and small amounts of peptides captured by class II MHC molecules. The details of antigen proteolysis, peptide capture and how destruction of T-cell epitopes is avoided are incompletely understood. Using the tetanus toxin antigen, we show that the introduction of 3-6 cleavage sites is sufficient to trigger a partially unfolded conformation able to bind to class II MHC molecules. The known locations of T-cell epitopes and protease cleavage sites predict that large domains of processed antigen (8-35 kDa) are captured under these conditions. Remarkably, when antigen is bound to the B-cell antigen receptor (BCR), processing can trigger a concerted 'hand-over' reaction whereby BCR-associated processed antigen is captured by neighbouring class II MHC molecules. Early capture of minimally processed antigen and confinement of the processing and class II MHC loading reaction to the membrane plane may improve the likelihood of T-cell epitope survival in the class II MHC pathway and may help explain the reciprocal relationships observed between B- and T-cell epitopes in many protein antigens and autoantigens.
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Affiliation(s)
- Catherine X Moss
- Division of Cell Biology & Immunology, School of Life Sciences, University of Dundee, Dundee, UK
| | - Timothy I Tree
- Department of Immunobiology, King's College London, Guy's King's & St Thomas' School of Medicine, London, UK
| | - Colin Watts
- Division of Cell Biology & Immunology, School of Life Sciences, University of Dundee, Dundee, UK
- Division of Cell Biology and Immunology, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK. Tel.: +44 1382 384233; Fax: +44 1382 385783; E-mail:
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Arif S, Tree TI, Astill TP, Tremble JM, Bishop AJ, Dayan CM, Roep BO, Peakman M. Autoreactive T cell responses show proinflammatory polarization in diabetes but a regulatory phenotype in health. J Clin Invest 2004; 113:451-63. [PMID: 14755342 PMCID: PMC324541 DOI: 10.1172/jci19585] [Citation(s) in RCA: 359] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2003] [Accepted: 11/25/2003] [Indexed: 01/28/2023] Open
Abstract
According to the quality of response they mediate, autoreactive T cells recognizing islet beta cell peptides could represent both disease effectors in the development of type 1 diabetes (T1DM) and directors of tolerance in nondiabetic individuals or those undergoing preventative immunotherapy. A combination of the rarity of these cells, inadequate technology, and poorly defined epitopes, however, has hampered examination of this paradigm. We have identified a panel of naturally processed islet epitopes by direct elution from APCs bearing HLA-DR4. Employing these epitopes in a sensitive, novel cytokine enzyme-linked immunosorbent spot assay, we show that the quality of autoreactive T cells in patients with T1DM exhibits extreme polarization toward a proinflammatory Th1 phenotype. Furthermore, we demonstrate that rather than being unresponsive, the majority of nondiabetic, HLA-matched control subjects also manifest a response against islet peptides, but one that shows extreme T regulatory cell (Treg, IL-10-secreting) bias. We conclude that development of T1DM depends on the balance of autoreactive Th1 and Treg cells, which may be open to favorable manipulation by immune intervention.
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Affiliation(s)
- Sefina Arif
- Department of Immunobiology, Guy's, King's and St. Thomas' School of Medicine, King's College London, Guy's Campus, London, United Kingdom
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7
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Peakman M, Tree TI, Endl J, van Endert P, Atkinson MA, Roep BO. Characterization of preparations of GAD65, proinsulin, and the islet tyrosine phosphatase IA-2 for use in detection of autoreactive T-cells in type 1 diabetes: report of phase II of the Second International Immunology of Diabetes Society Workshop for Standardization of T-cell assays in type 1 diabetes. Diabetes 2001; 50:1749-54. [PMID: 11473034 DOI: 10.2337/diabetes.50.8.1749] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The identification, quantification, and characterization of T-cells reactive with the islet autoantigens GAD65, proinsulin (PI), and tyrosine phosphatase-like molecules IA-2 and phogrin are major research goals in type 1 diabetes. In the Immunology of Diabetes Society First Workshop on Autoreactive T-Cells, the quality of recombinant preparations of these autoantigens was identified as a significant weakness, a finding that may account for much of the inconsistency in published studies of peripheral blood T-cell reactivity to islet autoantigens. Poor antigen quality has also hampered the development of novel technologies for the detection of islet-reactive T-cells. For these reasons, in the present study, several preparations of GAD65, PI, and IA-2 were collected and evaluated for endotoxin content, ability to stimulate a panel of relevant T-cell clones, and inhibitory effects on proliferation to unrelated third-party antigens. Through this process, we have been able to identify preparations of GAD65 and IA-2, generated in insect cells using the baculovirus expression system, that stimulate relevant clones and display low inhibitory effects on third-party antigens. In addition, we characterized a PI preparation generated in bacteria as being free of effects on proliferation to third-party antigens and low in endotoxin content. These preparations are important to promote the development of robust and sensitive assays of islet-reactive T-cells in patients with type 1 diabetes or patients at high risk for developing the disease.
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Affiliation(s)
- M Peakman
- Department of Immunology, Guy's King's and St. Thomas' School of Medicine, London, United Kingdom.
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8
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Tree TI, O'Byrne D, Tremble JM, MacFarlane WM, Haskins K, James RF, Docherty K, Hutton JC, Banga JP. Evidence for recognition of novel islet T cell antigens by granule-specific T cell lines from new onset type 1 diabetic patients. Clin Exp Immunol 2000; 121:100-5. [PMID: 10886245 PMCID: PMC1905664 DOI: 10.1046/j.1365-2249.2000.01279.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Type 1 diabetes is a T cell-mediated autoimmune disease where a number of islet beta-cell target autoantigens have been characterized on the basis of reactivity with autoantibodies. Nevertheless, there remains uncertainty of the nature of another group of autoantigens associated with the secretory granule fraction of islet beta-cells that appear to be targeted predominantly by autoreactive T cells. We have previously characterized CD4+, HLA-DR-restricted T cell lines from new onset type 1 diabetic patients that are specific for the secretory granule fraction of rat tumour insulinoma, RIN. The T cell line from the first patient, HS, proliferates in response to crude microsomal membranes prepared from a recently established, pure human islet beta-cell line NES2Y. In addition, the HS line also responds to secretory granule fractions prepared from a murine tumour insulinoma grown in RIP-Tag mice, showing the recognition of species-conserved antigen(s) in beta-cells. Using partially matched antigen-presenting cells, the HS T cells and another line derived from a second patient, MR, were shown to be restricted by disease-associated DRB1*0101 and DRB1*0404 alleles, respectively. Neither the HS or MR T cell lines proliferate in response to a large panel of candidate islet cell antigens, including insulin, proinsulin, glutamic acid decarboxylase, the protein tyrosine phosphatase IA-2/phogrin, imogen-38, ICA69 or hsp60. Our data provide compelling evidence of the presence of a group of antigens associated with the secretory granule fraction of islet beta-cells recognized by the T cell lines, whose definition may contribute to our knowledge of disease induction as well as to diagnosis.
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Affiliation(s)
- T I Tree
- GKT School of Medicine, Division of Medicine, Denmark Hill Campus, London, UK
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9
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Tree TI, Morgenthaler NG, Duhindan N, Hicks KE, Madec AM, Scherbaum WA, Banga JP. Two amino acids in glutamic acid decarboxylase act in concert for maintenance of conformational determinants recognised by Type I diabetic autoantibodies. Diabetologia 2000; 43:881-9. [PMID: 10952461 DOI: 10.1007/s001250051465] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
AIMS/HYPOTHESIS Glutamic acid decarboxylase 65 is a major autoantigen in Type I (insulin-dependent) diabetes mellitus, autoimmune polyendocrine syndrome and stiff-man syndrome. These disorders are characterised by the presence of multiple autoantibodies to the autoantigen which can be distinguished in a variety of different ways. We have investigated the role of single amino-acid mutations in glutamic acid decarboxylase 65 in distinguishing the binding of serum antibodies and a variety of patient-derived human IgG monoclonal antibodies directed to different determinants of the autoantigen. METHODS We identified a mutant of glutamic acid decarboxylase 65 that contained four single amino-acid mutations from the wild-type molecule. The role of these mutations was investigated by site-directed mutagenesis. We investigated the binding of patient-derived serum antibodies to glutamic acid decarboxylase 65 to a number of single and double amino-acid mutants using immunoprecipitation with labelled, recombinant antigen. To overcome the heterogeneity of different anti-glutamic acid decarboxylase 65 antibodies present in a patient's serum, the binding of a panel of eleven patient-derived human monoclonal antibodies recognising different determinants on the autoantigen was also studied. RESULTS Two replacements in glutamic acid decarboxylase 65 at Asn247Ser and Leu574Pro were identified that preferentially influence the anti-glutamic acid decarboxylase 65 serum antibodies of Type I diabetic patients, without statistically significantly effecting those recognised in other disorders. Single or double amino-acid replacements Asn247Ser and Leu574Pro in the autoantigen showed differential affects on expression of epitopes recognised by the human monoclonals. The double replacement of Asn247Ser and Leu574Pro in glutamic acid decarboxylase 65 resulted in the loss of binding of all eleven human monoclonal antibodies, irrespective of their epitope recognition. In contrast, single replacement of Leu574Pro statistically significantly reduced the binding of some carboxyl terminal-directed antibodies such as MICA 1, MICA 3 and DP-A without influencing the binding of other monoclonals. Replacement of Asn247Ser did not, however, influence the binding of any patients serum or human monoclonal antibodies. CONCLUSION/INTERPRETATION Two distantly spaced amino acids, Asn247 and Leu574 in glutamic acid decarboxylase 65 were identified that act in concert to greatly influence the conformational structure of the autoantigen and statistically significantly influence the binding of antibodies present in Type I diabetic sera. The single or double amino-acid mutants can be used to distinguish some anti-glutamic acid decarboxylase-65 autoantibodies and could prove useful in distinguishing Type I diabetic from autoimmune polyendocrine syndrome and stiff-man syndrome patients' sera as well as to study changes in antibody patterns during disease progression.
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Affiliation(s)
- T I Tree
- Guy's, King's, St Thomas' School of Medicine, Division of Medicine, London, UK
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10
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Stewart GR, Zhu Y, Parredes W, Tree TI, Guderian R, Bradley JE. The novel cuticular collagen Ovcol-1 of Onchocerca volvulus is preferentially recognized by immunoglobulin G3 from putatively immune individuals. Infect Immun 1997; 65:164-70. [PMID: 8975907 PMCID: PMC174571 DOI: 10.1128/iai.65.1.164-170.1997] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The cDNA sequence encoding an Onchocerca volvulus collagen, Ovcol-1, has been isolated and the corresponding native antigen has been identified. The cDNA encodes an open reading frame of 96 amino acid residues containing an uninterrupted 66-residue Gly-X-Y repeat triple-helical (TH) domain (where X and Y may be any amino acids) flanked by a 26-residue amino non-TH domain and a 4-residue carboxyl non-TH domain. The size (9.7 kDa) and structure of the deduced molecule are unique among previously identified collagen chains. This novel collagen type has been designated "mini-chain collagen." Native Ovcol-1 is aqueous soluble and resolves by sodium dodecyl sulfate-polyacrylamide gel electrophoresis at 14.2 kDa under reducing conditions. Immunoelectron microscopy of adult female O. volvulus localized Ovcol-1 to the cuticles of both the adult worm and uterine microfilaria. A group of individuals from an area in Ecuador where O. volvulus is hyperendemic have been classified as putatively immune (PI) to O. volvulus infection. Analysis of the humoral immune responses to Ovcol-1 demonstrated that immunoglobulin G3 (IgG3) of PI individuals preferentially recognized this antigen in comparison to IgG3 of infected individuals.
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Affiliation(s)
- G R Stewart
- Department of Biology, Imperial College, London, United Kingdom
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11
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Bradley JE, Elson L, Tree TI, Stewart G, Guderian R, Calvopiña M, Paredes W, Araujo E, Nutman TB. Resistance to Onchocerca volvulus: differential cellular and humoral responses to a recombinant antigen, OvMBP20/11. J Infect Dis 1995; 172:831-7. [PMID: 7658078 DOI: 10.1093/infdis/172.3.831] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Persons putatively immune (PI) to Onchocerca volvulus (Ov) infection were identified in Ecuador on the basis of epidemiologic, clinical, and parasitologic findings. Immune responses of PI subjects to a recombinant onchocercal protein, OvMBP20/11, were determined and compared with those of a comparable infected (INF) group from the same Ov-endemic area. PI subjects had significantly less antibody reactivity to this molecule; however, not all INF subjects had an antibody response. IgG1 and IgG4 were the predominant IgG subclasses induced to this molecule, and the amount of IgG1 produced was the only significant difference between the PI and INF groups. In contrast to the antibody responses, proliferative responses to OvMBP20/11 were significantly higher in PI than in INF subjects. Cytokine analysis of peripheral blood mononuclear cell culture supernatants revealed that INF subjects produced significantly more interleukin-10 in response to OvMBP20/11 than did PI subjects. This antigen induced few other cytokines, and there were no differences between study groups.
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Affiliation(s)
- J E Bradley
- Department of Biology, Imperial College, London, United Kingdom
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12
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Tree TI, Gillespie AJ, Shepley KJ, Blaxter ML, Tuan RS, Bradley JE. Characterisation of an immunodominant glycoprotein antigen of Onchocerca volvulus with homologues in other filarial nematodes and Caenorhabditis elegans. Mol Biochem Parasitol 1995; 69:185-95. [PMID: 7770083 DOI: 10.1016/0166-6851(94)00204-z] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The full-length cDNA corresponding to an Onchocerca volvulus antigen, OvMBP/11, which had been selected as a serodiagnostic tool was isolated, sequenced, and the native antigen encoded by the cDNA characterised. The cDNA encodes a protein of 20.5 kDa (termed Ov 20) containing a putative signal peptide. Southern blot analysis indicates that there is only a single O. volvulus gene corresponding to Ov 20 but it has significant sequence similarity to genes corresponding to two 20.5-kDa predicted proteins of Caenorhabditis elegans. Homologues of the Ov 20 gene were detected at high stringency by Southern blot in the other Onchocerca species O. gibsoni, and O. gutturosa and at lower stringency in the related filarial nematodes Brugia malayi and Acanthocheilonema viteae. The Ov 20 native antigen has two molecular mass forms, 20 and 22 kDa, in all the life cycle stages studied. These isoforms have different levels of N-linked glycosylation on a peptide backbone of 17.5 kDa. Immunolocalisation and in situ hybridisation studies demonstrated that Ov 20 is transcribed and translated in the body wall of adult females and also in microfilariae, third and fourth stage larvae. Antigen was detected in the supernatant of in vitro cultured adult female nematodes. The B. malayi and A. viteae homologues are antigenically cross-reactive to Ov 20, share the same size peptide backbone but differ in their degree of glycosylation.
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Affiliation(s)
- T I Tree
- Department of Biology, Imperial College, London, UK
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13
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Trenholme KR, Tree TI, Gillespie AJ, Guderian R, Maizels RM, Bradley JE. Heterogeneity of IgG antibody responses to cloned Onchocerca volvulus antigens in microfiladermia positive individuals from Esmeraldas Province, Ecuador. Parasite Immunol 1994; 16:201-9. [PMID: 8058358 DOI: 10.1111/j.1365-3024.1994.tb00341.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The prevalence of IgG antibodies to three recombinant O. volvulus antigens, OvMBP/10, OvMBP/11 and OvMBP/29 was determined in a group of 94 microfilaria positive (mf+) individuals resident in the hyperendemic onchocercal area of Esmeraldas Province, Ecuador. Clone OvMBP/11 was the antigen most frequently recognized by patients sera followed by OvMBP/10 and OvMBP/29. When a cocktail of the three recombinant antigens was used the proportion of positive sera increased to 100%. Antibody responses to the fusion partner maltose binding protein (MBP) were low in comparison with those to the cloned antigens and no correlation of responses between individual antigens was observed. The relative level of antibody response to each of the clones in the cocktail varied between individuals. The distribution of IgG responses to OvMBP/11 was bimodal and those to OvMBP/29 and OvMBP/10 were positively and negatively skewed, respectively. When the three recombinant antigens were used in combination this variation was minimized and the pattern of responses showed a normal distribution as was also seen to crude O. volvulus antigen. The cocktail of recombinants thus offers excellent diagnostic sensitivity in combination with the parasite specificity demonstrated previously.
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Affiliation(s)
- K R Trenholme
- Department of Biology, Imperial College of Science, Technology and Medicine, London, UK
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Bradley JE, Tuan RS, Shepley KJ, Tree TI, Maizels RM, Helm R, Gregory WF, Unnasch TR. Onchocerca volvulus: characterization of an immunodominant hypodermal antigen present in adult and larval parasites. Exp Parasitol 1993; 77:414-24. [PMID: 8253155 DOI: 10.1006/expr.1993.1101] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Biochemical and immunological data suggest that a relatively limited number of polypeptide antigens of viable Onchocerca volvulus-infective larvae are available to be recognized by the host's immune system. A partial cDNA clone encoding one such antigen, designated lambda RAL-2, was isolated by screening an expression cDNA library with antisera raised against viable O. volvulus L3. The antigen encoded by this clone was subsequently found to be immunogenic in the majority of individuals exposed to O. volvulus. In the present study, the native antigen corresponding to lambda RAL-2 (Ov17) has been characterized. Immunolocalization and in situ hybridization techniques have been used to localize Ov17 in adult and larval stages of the parasite. In adult females, Ov17 was localized primarily in the hypodermis. Ov17 was accessible to surface labeling reagents in viable adult parasites. Full-length cDNA clones encoding Ov17 suggested that the nascent protein contains a putative leader sequence, which is almost immediately followed by a polyglutamine tract. Analysis of antibody reactivity to recombinant proteins containing and lacking the polyglutamine tract demonstrated that this structure was not a significant B cell epitope in individuals exposed to O. volvulus.
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Affiliation(s)
- J E Bradley
- Department of Biology, Imperial College of Science Technology and Medicine, London, United Kingdom
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