| 1. |
- Battaglia, Manuela, et al.
(författare)
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Understanding and preventing type 1 diabetes through the unique working model of TrialNet
- 2017
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Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 0012-186X .- 1432-0428. ; 60:11, s. 2139-2147
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Tidskriftsartikel (refereegranskat)abstract
- Type 1 diabetes is an autoimmune disease arising from the destruction of pancreatic insulin-producing beta cells. The disease represents a continuum, progressing sequentially at variable rates through identifiable stages prior to the onset of symptoms, through diagnosis and into the critical periods that follow, culminating in a variable depth of beta cell depletion. The ability to identify the very earliest of these presymptomatic stages has provided a setting in which prevention strategies can be trialled, as well as furnishing an unprecedented opportunity to study disease evolution, including intrinsic and extrinsic initiators and drivers. This niche opportunity is occupied by Type 1 Diabetes TrialNet, an international consortium of clinical trial centres that leads the field in intervention and prevention studies, accompanied by deep longitudinal bio-sampling. In this review, we focus on discoveries arising from this unique bioresource, comprising more than 70,000 samples, and outline the processes and science that have led to new biomarkers and mechanistic insights, as well as identifying new challenges and opportunities. We conclude that via integration of clinical trials and mechanistic studies, drawing in clinicians and scientists and developing partnership with industry, TrialNet embodies an enviable and unique working model for understanding a disease that to date has no cure and for designing new therapeutic approaches.
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| 2. |
- Gerstner, Christina, et al.
(författare)
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Functional and Structural Characterization of a Novel HLA-DRB1*04:01-Restricted alpha-Enolase T Cell Epitope in Rheumatoid Arthritis
- 2016
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Ingår i: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Antibodies to citrullinated proteins, common in rheumatoid arthritis (RA) patients, are strongly associated to a specific set of HLA-DR alleles including HLA-DRB1*04:01, *04:04, and *01:01. Here, we first demonstrate that autoantibody levels toward the dominant citrullinated B cell epitope from alpha-enolase are significantly elevated in HLA-DRB1*04:01-positive RA patients. Furthermore, we identified alpha-enolase-derived T cell epitopes and demonstrated that native and citrullinated versions of several peptides bind with different affinities to HLA-DRB1*04:01, *04:04, and *01:01. The citrulline residues in the eight identified peptides are distributed throughout the entire length of the presented epitopes and more specifically, localized at peptide positions p-2, p2, p4, p6, p7, p10, and p11. Importantly, in contrast to its native version peptide 26 (TSKGLFRAAVPSGAS), the HLA-DRB1*04:01-restricted citrullinated peptide Cit26 (TSKGLFCitAAVPSGAS) elicited significant functional T cell responses in primary cells from RA patients. Comparative analysis of the crystal structures of HLA-DRB1*04:01 in complex with peptide 26 or Cit26 demonstrated that the posttranslational modification did not alter the conformation of the peptide. And since citrullination is the only structural difference between the two complexes, this indicates that the neo-antigen Cit26 is recognized by T cells with high specificity to the citrulline residue.
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| 3. |
- Pieper, Jennifer, et al.
(författare)
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Memory T cells specific to citrullinated alpha-enolase are enriched in the rheumatic joint
- 2018
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Ingår i: Journal of Autoimmunity. - : ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD. - 0896-8411 .- 1095-9157. ; 92, s. 47-56
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Tidskriftsartikel (refereegranskat)abstract
- ACPA-positive rheumatoid arthritis (RA) is associated with distinct HLA-DR alleles and immune responses to many citrullinated self-antigens. Herein we investigated the T cell epitope confined within alpha-enolase(326-340) in the context of HLA-DRB1*04:01 and assessed the corresponding CD4(+) T cells in both the circulation and in the rheumatic joint. Comparative crystallographic analyses were performed for the native and citrullinated alpha-enolase(326-340) peptides in complex with HLA-DRB1*04:01. HLA-tetramers assembled with either the native or citrullinated peptide were used for ex vivo and in vitro assessment of a enolase-specific T cells in peripheral blood, synovial fluid and synovial tissue by flow cytometry. The native and modified peptides take a completely conserved structural conformation within the peptide binding cleft of HLA-DRB1*04:01. The citrulline residue-327 was located N-terminally, protruding towards TCRs. The frequencies of T cells recognizing native eno(326-340) were similar in synovial fluid and peripheral blood, while in contrast, the frequency of T cells recognizing cit-eno(326-340) was significantly elevated in synovial fluid compared to peripheral blood (3.6-fold, p = 0.0150). Additionally, citrulline-specific T cells with a memory phenotype were also significantly increased (1.6-fold, p = 0.0052) in synovial fluid compared to peripheral blood. The native T cell epitope confined within alpha-enolase(326-340) does not appear to lead to complete negative selection of cognate CD4(+) T cells. In RA patient samples, only T cells recognizing the citrullinated version of alpha-enolase(326-340) were found at elevated frequencies implicating that neo-antigen formation is critical for breach of tolerance. (C) 2018 Elsevier Ltd. All rights reserved.
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| 4. |
- Snir, Omri, et al.
(författare)
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Multifunctional T cell reactivity with native and glycosylated type II collagen in rheumatoid arthritis
- 2012
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Ingår i: Arthritis and Rheumatism. - : John Wiley & Sons. - 0004-3591 .- 1529-0131. ; 64:8, s. 2482-2488
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Tidskriftsartikel (refereegranskat)abstract
- Objective Type II collagen (CII) is a cartilage-specific protein to which a loss of immune tolerance may trigger autoimmune reactions and cause arthritis. The major T cell epitope on CII, amino acids 259273, can be presented by several HLADRB1*04 alleles in its native or posttranslational glycosylated form. The present study was undertaken to functionally explore and compare CII-autoreactive T cells from blood and synovial fluid of patients with rheumatoid arthritis (RA).Methods Peripheral blood was obtained from HLADRB1*04positive RA patients (n = 10) and control subjects (n = 10) and stimulated in vitro with several variants of the CII259273 epitope, i.e., unmodified, glycosylated on Lys-264, glycosylated on Lys-270, or glycosylated on both Lys-264 and Lys-270. Up-regulation of CD154 was used to identify responding T cells. These cells were further characterized by intracellular staining for interleukin-17 (IL-17), interferon-? (IFN?), and IL-2 by flow cytometry. Synovial T cells from RA patients were investigated in parallel.Results Multifunctional T cell responses toward all examined variants of the CII259273 peptide could be detected in RA patients and, to a lesser extent, also in healthy HLA-matched controls (P < 0.001). In RA patients, a comparison between blood- and joint-derived T cell function revealed a significant increase in levels of the proinflammatory cytokine IFN? in synovial T cells (P = 0.027). Studies of longitudinally obtained samples showed that T cell responses were sustained over the course of disease, and even included epitope spreading.Conclusion The identification of inflammatory T cell responses to both glycosylated and nonglycosylated variants of the major CII epitope in RA patients suggests that CII autoreactivity in RA may be more common than previously recognized.
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