| 1. |
- Boeiers, Ulrika, et al.
(författare)
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Collagen type II is recognized by a pathogenic antibody through germline encoded structures
- 2008
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Ingår i: European Journal of Immunology. - : Wiley. - 1521-4141 .- 0014-2980. ; 38:10, s. 2784-2795
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Tidskriftsartikel (refereegranskat)abstract
- Collagen type II (CII) is a cartilage-specific target of pathologic humoral autoimmune responses in rheumatoid arthritis as well as in the collagen-induced arthritis model. The aim of the present study is to investigate the critical amino acid residues conferring CII epitope specificity of the prototypic arthritogenic murine mAb CIIC1. A homology model of the CIIC1 single-chain antibody fragment (CIIC1scFv) in complex with its triple helical epitope was established. in silico predictions based on extensive molecular dynamics simulations were experimentally tested by the recombinant expression and functional analysis of CIIC1scFv containing alanine replacements allowing the identification of crucial CII-binding sites in the CDR2 and CDR3 regions of both heavy and light chains. Since the conversion of the CIIC1scFv sequence into the respective germline at all 13 somatically mutated positions did not affect its CII binding, our data indicate that potentially harmful cartilage-specific humoral autoimmunity could be germline encoded. The molecular modeling further demonstrates that the rigid collagen triple helix restricts the likelihood of molecular interactions with the CDR regions of the antibody considerably compared with globular antigens. These sterical constraints provide an explanation as to why somatic mutations in the arthritogenic autoantibody have no obvious impact on CII recognition.
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| 2. |
- Ge, Changrong, et al.
(författare)
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Key interactions in the trimolecular complex consisting of the rheumatoid arthritis-associated DRB1*04:01 molecule, the major glycosylated collagen II peptide and the T-cell receptor
- 2022
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Ingår i: Annals of the Rheumatic Diseases. - : BMJ Publishing Group Ltd. - 0003-4967 .- 1468-2060. ; 81:4, s. 480-489
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Tidskriftsartikel (refereegranskat)abstract
- Objectives Rheumatoid arthritis (RA) is an autoimmune disease strongly associated with the major histocompatibility complex (MHC) class II allele DRB1*04:01, which encodes a protein that binds self-peptides for presentation to T cells. This study characterises the autoantigen-presenting function of DRB1*04:01 (HLA-DRA*01:01/HLA-DRB1*04:01) at a molecular level for prototypic T-cell determinants, focusing on a post-translationally modified collagen type II (Col2)-derived peptide.Methods The crystal structures of DRB1*04:01 molecules in complex with the peptides HSP70(289-306), citrullinated CILP982-996 and galactosylated Col2(259-273) were determined on cocrystallisation. T cells specific for Col2(259-273) were investigated in peripheral blood mononuclear cells from patients with DRB1*04:01-positive RA by cytofluorometric detection of the activation marker CD154 on peptide stimulation and binding of fluorescent DRB1*0401/Col2(259-273) tetramer complexes. The cDNAs encoding the T-cell receptor (TCR) alpha-chains and beta-chains were cloned from single-cell sorted tetramer-positive T cells and transferred via a lentiviral vector into TCR-deficient Jurkat 76 cells.Results The crystal structures identified peptide binding to DRB1*04:01 and potential side chain exposure to T cells. The main TCR recognition sites in Col2(259-273) were lysine residues that can be galactosylated. RA T-cell responses to DRB1*04:01-presented Col2(259-273) were dependent on peptide galactosylation at lysine 264. Dynamic molecular modelling of a functionally characterised Col2(259-273)-specific TCR complexed with DRB1*04:01/Col2(259-273) provided evidence for differential allosteric T-cell recognition of glycosylated lysine 264.Conclusions The MHC-peptide-TCR interactions elucidated in our study provide new molecular insights into recognition of a post-translationally modified RA T-cell determinant with a known dominant role in arthritogenic and tolerogenic responses in murine Col2-induced arthritis.
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| 3. |
- Apel, Maria, et al.
(författare)
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Variants in RUNX3 Contribute to Susceptibility to Psoriatic Arthritis, Exhibiting Further Common Ground With Ankylosing Spondylitis
- 2013
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Ingår i: Arthritis and Rheumatism. - : Wiley. - 0004-3591 .- 1529-0131. ; 65:5, s. 1224-1231
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Tidskriftsartikel (refereegranskat)abstract
- Objective Psoriatic arthritis (PsA) is a common inflammatory joint disease distinct from other chronic arthritides and frequently accompanied by psoriasis vulgaris. In a first genome-wide association study (GWAS), we were able to identify several genetic risk factors. However, even combined with previously identified factors, the genetic contribution to disease was not fully explained. Therefore, we undertook this study to investigate further 17 loci from our GWAS that did not reach genome-wide significance levels of association in the initial analysis. Methods Twenty-one of 22 single-nucleotide polymorphisms were successfully genotyped in independent cohorts of 1,398 PsA patients and 6,389 controls and in a group of 964 German patients with psoriasis vulgaris. Results Association with a RUNX3 variant, rs4649038, was replicated in independent patients and controls and resulted in a combined P value of 1.40 x 108 by Cochran-Mantel-Haenszel test and an odds ratio (OR) of 1.24 (95% confidence interval [95% CI] 1.151.33). Further analyses based on linkage disequilibrium (LD) at RUNX3 refined the most significant association to an LD block located in the first intron of one isoform. Weaker evidence for association was detected in German patients with psoriasis vulgaris (P = 5.89 x 102; OR 1.13 [95% CI 1.001.28]), indicating a role in the skin manifestations of psoriasis. Conclusion Our analyses identified variants in RUNX3 as susceptibility factors for PsA. RUNX3 has already been implicated in susceptibility to ankylosing spondylitis, another spondyloarthritis, although its risk allele is independent from the one for PsA. RUNX-3 is involved in CD8+ T lymphocyte differentiation and is therefore a good candidate for involvement in PsA and psoriasis vulgaris as T cellmediated diseases.
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| 4. |
- Ge, Changrong P, et al.
(författare)
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Anti-citrullinated protein antibodies cause arthritis by cross-reactivity to joint cartilage
- 2017
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Ingår i: JCI INSIGHT. - : AMER SOC CLINICAL INVESTIGATION INC. - 2379-3708. ; 2:13
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Tidskriftsartikel (refereegranskat)abstract
- Today, it is known that autoimmune diseases start a long time before clinical symptoms appear. Anti-citrullinated protein antibodies (ACPAs) appear many years before the clinical onset of rheumatoid arthritis (RA). However, it is still unclear if and how ACPAs are arthritogenic. To better understand the molecular basis of pathogenicity of ACPAs, we investigated autoantibodies reactive against the C1 epitope of collagen type II (CII) and its citrullinated variants. We found that these antibodies are commonly occurring in RA. A mAb (ACC1) against citrullinated C1 was found to cross-react with several noncitrullinated epitopes on native CII, causing proteoglycan depletion of cartilage and severe arthritis in mice. Structural studies by X-ray crystallography showed that such recognition is governed by a shared structural motif "RG-TG" within all the epitopes, including electrostatic potential-controlled citrulline specificity. Overall, we have demonstrated a molecular mechanism that explains how ACPAs trigger arthritis.
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| 5. |
- Hüffmeier, Ulrike, et al.
(författare)
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Common variants at TRAF3IP2 are associated with susceptibility to psoriatic arthritis and psoriasis
- 2010
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 42:11, s. 996-999
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Tidskriftsartikel (refereegranskat)abstract
- Psoriatic arthritis (PsA) is an inflammatory joint disease that is distinct from other chronic arthritides and which is frequently accompanied by psoriasis vulgaris (PsV) and seronegativity for rheumatoid factor. We conducted a genome-wide association study in 609 German individuals with PsA (cases) and 990 controls with replication in 6 European cohorts including a total of 5,488 individuals. We replicated PsA associations at HLA-C and IL12B and identified a new association at TRAF3IP2 (rs13190932, P = 8.56 × 10⁻¹⁷). TRAF3IP2 was also associated with PsV in a German cohort including 2,040 individuals (rs13190932, P = 1.95 × 10⁻³). Sequencing of the exons of TRAF3IP2 identified a coding variant (p.Asp10Asn, rs33980500) as the most significantly associated SNP (P = 1.13 × 10⁻²⁰, odds ratio = 1.95). Functional assays showed reduced binding of this TRAF3IP2 variant to TRAF6, suggesting altered modulation of immunoregulatory signals through altered TRAF interactions as a new and shared pathway for PsA and PsV.
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| 6. |
- Merky, Patrick, et al.
(författare)
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Visualization and phenotyping of proinflammatory antigen-specific T cells during collagen-induced arthritis in a mouse with a fixed collagen type II-specific transgenic T-cell receptor beta-chain
- 2010
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Ingår i: Arthritis Research and Therapy. - : Springer Science and Business Media LLC. - 1478-6362 .- 1478-6354. ; 12:4
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: The V beta 12-transgenic mouse was previously generated to investigate the role of antigen-specific T cells in collagen-induced arthritis (CIA), an animal model for rheumatoid arthritis. This mouse expresses a transgenic collagen type II (CII)-specific T-cell receptor (TCR) beta-chain and consequently displays an increased immunity to CII and increased susceptibility to CIA. However, while the transgenic V beta 12 chain recombines with endogenous alpha-chains, the frequency and distribution of CII-specific T cells in the V beta 12-transgenic mouse has not been determined. The aim of the present report was to establish a system enabling identification of CII-specific T cells in the V beta 12-transgenic mouse in order to determine to what extent the transgenic expression of the CII-specific beta-chain would skew the response towards the immunodominant galactosylated T-cell epitope and to use this system to monitor these cells throughout development of CIA. Methods: We have generated and thoroughly characterized a clonotypic antibody, which recognizes a TCR specific for the galactosylated CII(260-270) peptide in the V beta 12-transgenic mouse. Hereby, CII-specific T cells could be quantified and followed throughout development of CIA, and their phenotype was determined by combinatorial analysis with the early activation marker CD154 (CD40L) and production of cytokines. Results: The V beta 12-transgenic mouse expresses several related but distinct T-cell clones specific for the galactosylated CII peptide. The clonotypic antibody could specifically recognize the majority (80%) of these. Clonotypic T cells occurred at low levels in the naive mouse, but rapidly expanded to around 4% of the CD4(+) T cells, whereupon the frequency declined with developing disease. Analysis of the cytokine profile revealed an early Th1-biased response in the draining lymph nodes that would shift to also include Th17 around the onset of arthritis. Data showed that Th1 and Th17 constitute a minority among the CII-specific population, however, indicating that additional subpopulations of antigen-specific T cells regulate the development of CIA. Conclusions: The established system enables the detection and detailed phenotyping of T cells specific for the galactosylated CII peptide and constitutes a powerful tool for analysis of the importance of these cells and their effector functions throughout the different phases of arthritis.
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| 7. |
- Romero-Castillo, Laura, et al.
(författare)
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Human MHC Class II and Invariant Chain Knock-in Mice Mimic Rheumatoid Arthritis with Allele Restriction in Immune Response and Arthritis Association
- 2024
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Ingår i: Advanced Science. - 2198-3844.
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Tidskriftsartikel (refereegranskat)abstract
- Transgenic mice expressing human major histocompatibility complex class II (MHCII) risk alleles are widely used in autoimmune disease research, but limitations arise due to non-physiologic expression. To address this, physiologically relevant mouse models are established via knock-in technology to explore the role of MHCII in diseases like rheumatoid arthritis. The gene sequences encoding the ectodomains are replaced with the human DRB1*04:01 and 04:02 alleles, DRA, and CD74 (invariant chain) in C57BL/6N mice. The collagen type II (Col2a1) gene is modified to mimic human COL2. Importantly, DRB1*04:01 knock-in mice display physiologic expression of human MHCII also on thymic epithelial cells, in contrast to DRB1*04:01 transgenic mice. Humanization of the invariant chain enhances MHCII expression on thymic epithelial cells, increases mature B cell numbers in spleen, and improves antigen presentation. To validate its functionality, the collagen-induced arthritis (CIA) model is used, where DRB1*04:01 expression led to a higher susceptibility to arthritis, as compared with mice expressing DRB1*04:02. In addition, the humanized T cell epitope on COL2 allows autoreactive T cell-mediated arthritis development. In conclusion, the humanized knock-in mouse faithfully expresses MHCII, confirming the DRB1*04:01 alleles role in rheumatoid arthritis and being also useful for studying MHCII-associated diseases.
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| 8. |
- Urbonaviciute, Vilma, et al.
(författare)
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Therapy targeting antigen-specific T cells by a peptide-based tolerizing vaccine against autoimmune arthritis
- 2023
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - Stockholm : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 120:25
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Tidskriftsartikel (refereegranskat)abstract
- A longstanding goal has been to find an antigen-specific preventive therapy, i.e., a vaccine, for autoimmune diseases. It has been difficult to find safe ways to steer the targeting of natural regulatory antigen. Here, we show that the administration of exog-enous mouse major histocompatibility complex class II protein bounding a unique galactosylated collagen type II (COL2) peptide (Aq-galCOL2) directly interacts with the antigen-specific TCR through a positively charged tag. This leads to expanding a VISTA-positive nonconventional regulatory T cells, resulting in a potent dominant suppressive effect and protection against arthritis in mice. The therapeutic effect is dom-inant and tissue specific as the suppression can be transferred with regulatory T cells, which downregulate various autoimmune arthritis models including antibody-induced arthritis. Thus, the tolerogenic approach described here may be a promising dominant antigen-specific therapy for rheumatoid arthritis, and in principle, for autoimmune diseases in general.
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| 9. |
- Uysal, Hüseyin, et al.
(författare)
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Antibodies to citrullinated proteins : molecular interactions and arthritogenicity
- 2010
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Ingår i: Immunological Reviews. - Hoboken, NJ : Wiley-Blackwell Publishing Inc.. - 0105-2896 .- 1600-065X. ; 233:1, s. 9-33
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Tidskriftsartikel (refereegranskat)abstract
- The discovery of antibodies specific for citrullinated protein epitopes [anti-citrullinated protein antibodies (ACPAs)] is a hallmark for the diagnosis and prognosis of rheumatoid arthritis (RA) and will also be a useful tool for understanding the fundamental pathologic processes. There are several essential questions pertaining to ACPA that remain to be explored, such as understanding the early specificity of the underlying T-cell recognition, whether the production of ACPA is a primary or secondary process, and in the event of such antibodies being arthritogenic, whether they could possibly regulate the disease development. To answer these questions, animal models are needed, but unfortunately ACPA is not a prominent feature of any of the classical animal models of RA. However, we showed recently that ACPA can be isolated from animals susceptible to collagen-induced arthritis that are specific for citrullinated type II collagen (CII). The citrulline specificity could be visualized, and the specificity is determined primarily by a direct interaction with citrulline. We also demonstrated that these antibodies are specific for the citrullinated epitopes and are pathogenic in vivo. A new hypothesis to explain how inflammation in RA can be directed to cartilaginous joints and be self-perpetuating is suggested, which involves recognition of post-translational modifications (glycosylation and citrullination) on CII by T and B cells that can have both arthritogenic and regulatory consequences. © 2009 John Wiley & Sons A/S.
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| 10. |
- Uysal, Hüseyin, et al.
(författare)
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Structure and pathogenicity of antibodies specific for citrullinated collagen type II in experimental arthritis
- 2009
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Ingår i: Journal of Experimental Medicine. - New York, NY : Rockefeller University Press. - 0022-1007 .- 1540-9538. ; 206:2, s. 449-462
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Tidskriftsartikel (refereegranskat)abstract
- Antibodies to citrulline-modified proteins have a high diagnostic value in rheumatoid arthritis (RA). However, their biological role in disease development is still unclear. To obtain insight into this question, a panel of mouse monoclonal antibodies was generated against a major triple helical collagen type II (CII) epitope (position 359-369; ARGLTGRPGDA) with or without arginines modified by citrullination. These antibodies bind cartilage and synovial tissue, and mediate arthritis in mice. Detection of citrullinated CII from RA patients' synovial fluid demonstrates that cartilage-derived CII is indeed citrullinated in vivo. The structure determination of a Fab fragment of one of these antibodies in complex with a citrullinated peptide showed a surprising beta-turn conformation of the peptide and provided information on citrulline recognition. Based on these findings, we propose that autoimmunity to CII, leading to the production of antibodies specific for both native and citrullinated CII, is an important pathogenic factor in the development of RA.
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