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Loll B, Rückert C, Uchanska-Ziegler B, Ziegler A. Conformational Plasticity of HLA-B27 Molecules Correlates Inversely With Efficiency of Negative T Cell Selection. Front Immunol 2020; 11:179. [PMID: 32117305 PMCID: PMC7027375 DOI: 10.3389/fimmu.2020.00179] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 01/23/2020] [Indexed: 01/07/2023] Open
Abstract
The development of autoimmune disorders is incompletely understood. Inefficient thymic T cell selection against self-peptides presented by major histocompatibility antigens (HLA in humans) may contribute to the emergence of auto-reactive effector cells, and molecular mimicry between foreign and self-peptides could promote T cell cross-reactivity. A pair of class I subtypes, HLA-B2705 and HLA-B2709, have previously been intensely studied, because they are distinguished from each other only by a single amino acid exchange at the floor of the peptide-binding groove, yet are differentially associated with the autoinflammatory disorder ankylosing spondylitis. Using X-ray crystallography in combination with ensemble refinement, we find that the non-disease-associated subtype HLA-B2709, when presenting the self-peptide pGR (RRRWHRWRL), exhibits elevated conformational dynamics, and the complex can also be recognized by T cells. Both features are not observed in case of the sequence-related self-peptide pVIPR (RRKWRRWHL) in complex with this subtype, and T cell cross-reactivity between pGR, pVIPR, and the viral peptide pLMP2 (RRRWRRLTV) is only rarely observed. The disease-associated subtype HLA-B2705, however, exhibits extensive conformational flexibility in case of the three complexes, all of which are also recognized by frequently occurring cross-reactive T cells. A comparison of the structural and dynamic properties of the six HLA-B27 complexes, together with their individual ability to interact with T cells, permits us to correlate the flexibility of HLA-B27 complexes with effector cell reactivity. The results suggest the existence of an inverse relationship between conformational plasticity of peptide-HLA-B27 complexes and the efficiency of negative selection of self-reactive cells within the thymus.
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Affiliation(s)
- Bernhard Loll
- Institut für Chemie und Biochemie, Abteilung Strukturbiochemie, Freie Universität Berlin, Berlin, Germany,*Correspondence: Bernhard Loll
| | - Christine Rückert
- Institut für Immungenetik, Charité - Universitätsmedizin Berlin, Freie Universität Berlin, Berlin, Germany
| | - Barbara Uchanska-Ziegler
- Institut für Immungenetik, Charité - Universitätsmedizin Berlin, Freie Universität Berlin, Berlin, Germany,Ziegler Biosolutions, Waldshut-Tiengen, Germany
| | - Andreas Ziegler
- Ziegler Biosolutions, Waldshut-Tiengen, Germany,Andreas Ziegler
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Cauli A, Dessole G, Piga M, Angioni MM, Pinna S, Floris A, Congia M, Mascia E, Paladini F, Tedeschi V, Sorrentino R, Fiorillo MT, Mathieu A. Expression analysis of HLA-E and NKG2A and NKG2C receptors points at a role for natural killer function in ankylosing spondylitis. RMD Open 2018; 4:e000597. [PMID: 30018803 PMCID: PMC6045714 DOI: 10.1136/rmdopen-2017-000597] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2017] [Revised: 05/23/2018] [Accepted: 06/19/2018] [Indexed: 12/25/2022] Open
Abstract
Background Ankylosing spondylitis (AS) is a complex chronic inflammatory disease strongly associated with the majority of human leucocyte antigen (HLA)-B27 alleles. HLA-E molecules are non-classical major histocompatibility complex (MHC) class I molecules that specifically interact with the natural killer receptors NKG2A (inhibitory) and NKG2C (activating), and have been recently proposed to be involved in AS pathogenesis.''. Objective To analyse the expression of HLA-E and the CD94/NKG2 pair of receptors in HLA-B27-positive patients with AS and healthy controls (HC) bearing the AS-associated B*2705 and the non-AS-associated B*2709 alleles. Methods The level of surface expression of HLA-E molecules on CD14+ peripheral blood mononuclear cell was evaluated in 21 HLA-B*2705 patients with AS, 12 HLA-B*2705 HC, 12 HLA-B*2709 HC and 6 HLA-B27-negative HC using the monoclonal antibody MEM-E/08 by quantitative cytofluorimetric analysis. The percentage and density of expression of HLA-E ligands NKG2A and NKG2C were also measured on CD3-CD56+ NK cells. Results HLA-E expression in CD14+ cells was significantly higher in patients with AS (587.0, IQR 424-830) compared with B*2705 HC (389, IQR 251.3-440.5; p=0.0007), B*2709 HC (294.5, IQR 209.5-422; p=0.0004) and HLA-B27-negative HC (380, IQR 197.3-515.0; p=0.01). A higher number of NK cells expressing NKG2A compared with NKG2C were found in all cohorts analysed, as well as a higher cell surface density. Conclusion The higher surface level of HLA-E molecules in patients with AS compared with HC, concurrently with a prevalent expression of NKG2A, suggests that the crosstalk between these two molecules might play a role in AS pathogenesis, accounting for the previously reported association between HLA-E and AS.
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Affiliation(s)
- Alberto Cauli
- Rheumatology Unit, Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Grazia Dessole
- Rheumatology Unit, Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Matteo Piga
- Rheumatology Unit, Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Maria Maddalena Angioni
- Rheumatology Unit, Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Silvia Pinna
- Rheumatology Unit, Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Alberto Floris
- Rheumatology Unit, Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Mattia Congia
- Rheumatology Unit, Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Enrico Mascia
- Rheumatology Unit, Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Fabiana Paladini
- Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University of Rome, Rome, Italy
| | - Valentina Tedeschi
- Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University of Rome, Rome, Italy
| | - Rosa Sorrentino
- Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University of Rome, Rome, Italy
| | - Maria Teresa Fiorillo
- Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University of Rome, Rome, Italy
| | - Alessandro Mathieu
- Rheumatology Unit, Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
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Cauli A, Piga M, Dessole G, Porru G, Floris A, Vacca A, Desogus E, La Nasa G, Mathieu A. Killer-cell immunoglobulin-like receptors (KIR) and HLA-class I heavy chains in ankylosing spondylitis. Drug Dev Res 2015; 75 Suppl 1:S15-9. [PMID: 25381967 DOI: 10.1002/ddr.21187] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
HLA-B27 (B27) interactions with the killer-cell immunoglobulin-like receptors (KIR) have been implicated in the pathogenesis of ankylosing spondylitis (AS), with consistent differences among populations. KIR3DL1 and possibly KIR3DS1 interact with classical B27, whereas KIR3DL2 binds B27 heavy chain dimers. The aim of this review is to summarize data from recent studies performed in our laboratory and from the literature, which provide support for a possible role of KIR3DL2/B27 dimer interactions in the pathogenesis of AS. Recent studies in cells from AS patients and from health controls carrying the predisposing B*2705 and the nonpredisposing B*2709 haplotypes, have shown a higher percentage of positive cells and a higher surface expression of KIR3DL2 receptors on natural killer (NK) and CD4+ T cells in B*2705 AS patients compared with B*2705, B*2709 and B27-negative healthy controls. Increased expression of HC10-reactive molecules on AS monocytes was seen, supporting the possible role of the KIR3DL2/B272 pair in the pathogenesis of AS. These results underline the importance of NK cells and innate immunity, and of CD4+ T cells in the inflammatory pathogenesis of AS.
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Affiliation(s)
- Alberto Cauli
- Rheumatology Unit, Department of Medical Sciences, University of Cagliari, Cagliari, 090142, Italy
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Alvarez-Navarro C, Cragnolini JJ, Dos Santos HG, Barnea E, Admon A, Morreale A, López de Castro JA. Novel HLA-B27-restricted epitopes from Chlamydia trachomatis generated upon endogenous processing of bacterial proteins suggest a role of molecular mimicry in reactive arthritis. J Biol Chem 2013; 288:25810-25825. [PMID: 23867464 DOI: 10.1074/jbc.m113.493247] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Reactive arthritis (ReA) is an HLA-B27-associated spondyloarthropathy that is triggered by diverse bacteria, including Chlamydia trachomatis, a frequent intracellular parasite. HLA-B27-restricted T-cell responses are elicited against this bacterium in ReA patients, but their pathogenetic significance, autoimmune potential, and relevant epitopes are unknown. High resolution and sensitivity mass spectrometry was used to identify HLA-B27 ligands endogenously processed and presented by HLA-B27 from three chlamydial proteins for which T-cell epitopes were predicted. Fusion protein constructs of ClpC, Na(+)-translocating NADH-quinone reductase subunit A, and DNA primase were expressed in HLA-B27(+) cells, and their HLA-B27-bound peptidomes were searched for endogenous bacterial ligands. A non-predicted peptide, distinct from the predicted T-cell epitope, was identified from ClpC. A peptide recognized by T-cells in vitro, NQRA(330-338), was detected from the reductase subunit. This is the second HLA-B27-restricted T-cell epitope from C. trachomatis with relevance in ReA demonstrated to be processed and presented in live cells. A novel peptide from the DNA primase, DNAP(211-223), was also found. This was a larger variant of a known epitope and was highly homologous to a self-derived natural ligand of HLA-B27. All three bacterial peptides showed high homology with human sequences containing the binding motif of HLA-B27. Molecular dynamics simulations further showed a striking conformational similarity between DNAP(211-223) and its homologous and much more flexible human-derived HLA-B27 ligand. The results suggest that molecular mimicry between HLA-B27-restricted bacterial and self-derived epitopes is frequent and may play a role in ReA.
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Affiliation(s)
- Carlos Alvarez-Navarro
- From the Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma, Madrid, Spain and
| | - Juan J Cragnolini
- From the Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma, Madrid, Spain and
| | - Helena G Dos Santos
- From the Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma, Madrid, Spain and
| | - Eilon Barnea
- the Faculty of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Arie Admon
- the Faculty of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Antonio Morreale
- From the Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma, Madrid, Spain and
| | - José A López de Castro
- From the Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma, Madrid, Spain and.
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Magnacca A, Persiconi I, Nurzia E, Caristi S, Meloni F, Barnaba V, Paladini F, Raimondo D, Fiorillo MT, Sorrentino R. Characterization of a proteasome and TAP-independent presentation of intracellular epitopes by HLA-B27 molecules. J Biol Chem 2012; 287:30358-67. [PMID: 22807446 DOI: 10.1074/jbc.m112.384339] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Nascent HLA-class I molecules are stabilized by proteasome-derived peptides in the ER and the new complexes proceed to the cell surface through the post-ER vesicles. It has been shown, however, that less stable complexes can exchange peptides in the Trans Golgi Network (TGN). HLA-B27 are the most studied HLA-class I molecules due to their association with Ankylosing Spondylitis (AS). Chimeric proteins driven by TAT of HIV have been exploited by us to deliver viral epitopes, whose cross-presentation by the HLA-B27 molecules was proteasome and TAP-independent and not restricted to Antigen-Presenting Cells (APC). Here, using these chimeric proteins as epitope suppliers, we compared with each other and with the HLA-A2 molecules, the two HLA-B*2705 and B*2709 alleles differing at residue 116 (D116H) and differentially associated with AS. We found that the antigen presentation by the two HLA-B27 molecules was proteasome-, TAP-, and APC-independent whereas the presentation by the HLA-A2 molecules required proteasome, TAP and professional APC. Assuming that such difference could be due to the unpaired, highly reactive Cys-67 distinguishing the HLA-B27 molecules, C67S mutants in HLA-B*2705 and B*2709 and V67C mutant in HLA-A*0201 were also analyzed. The results showed that this mutation did not influence the HLA-A2-restricted antigen presentation while it drastically affected the HLA-B27-restricted presentation with, however, remarkable differences between B*2705 and B*2709. The data, together with the occurrence on the cell surface of unfolded molecules in the case of C67S-B*2705 mutant but not in that of C67S-B*2709 mutant, indicates that Cys-67 has a more critical role in stabilizing the B*2705 rather than the B*2709 complexes.
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Affiliation(s)
- Adriana Magnacca
- Department of Biology and Biotechnology C. Darwin, University of Rome, Rome, Italy
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Interaction pattern of Arg 62 in the A-pocket of differentially disease-associated HLA-B27 subtypes suggests distinct TCR binding modes. PLoS One 2012; 7:e32865. [PMID: 22403718 PMCID: PMC3293911 DOI: 10.1371/journal.pone.0032865] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 02/01/2012] [Indexed: 12/30/2022] Open
Abstract
The single amino acid replacement Asp116His distinguishes the two subtypes HLA-B*2705 and HLA-B*2709 which are, respectively, associated and non-associated with Ankylosing Spondylitis, an autoimmune chronic inflammatory disease. The reason for this differential association is so far poorly understood and might be related to subtype-specific HLA:peptide conformations as well as to subtype/peptide-dependent dynamical properties on the nanoscale. Here, we combine functional experiments with extensive molecular dynamics simulations to investigate the molecular dynamics and function of the conserved Arg62 of the α1-helix for both B27 subtypes in complex with the self-peptides pVIPR (RRKWRRWHL) and TIS (RRLPIFSRL), and the viral peptides pLMP2 (RRRWRRLTV) and NPflu (SRYWAIRTR). Simulations of HLA:peptide systems suggest that peptide-stabilizing interactions of the Arg62 residue observed in crystal structures are metastable for both B27 subtypes under physiological conditions, rendering this arginine solvent-exposed and, probably, a key residue for TCR interaction more than peptide-binding. This view is supported by functional experiments with conservative (R62K) and non-conservative (R62A) B*2705 and B*2709 mutants that showed an overall reduction in their capability to present peptides to CD8+ T cells. Moreover, major subtype-dependent differences in the peptide recognition suggest distinct TCR binding modes for the B*2705 versus the B*2709 subtype.
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Narzi D, Becker CM, Fiorillo MT, Uchanska-Ziegler B, Ziegler A, Böckmann RA. Dynamical Characterization of Two Differentially Disease Associated MHC Class I Proteins in Complex with Viral and Self-Peptides. J Mol Biol 2012; 415:429-42. [DOI: 10.1016/j.jmb.2011.11.021] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Revised: 11/01/2011] [Accepted: 11/10/2011] [Indexed: 10/15/2022]
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Abstract
This article summarizes the proceedings of a one-day international workshop held in July 2009 on the role of HLA-B27 in the pathogenesis of ankylosing spondylitis (AS) and related disorders. HLA-B27 is found in about 90% of patients with AS, with an odds ratio of about 100, but the mechanism underlying this association is not known. There are currently 3 major mechanistic hypotheses for this association: (1) T cell recognition of one or more B27 presented peptides; (2) B27 heavy-chain misfolding that induces an unfolded protein response; and (3) innate immune recognition of cell-surface expressed B27 heavy-chain dimers. None of these hypotheses accounts for the tissue specificity of the inflammation characteristic of AS. These hypotheses were discussed in the context of known epidemiologic, biochemical, structural, and immunologic differences among HLA-B27 subtypes; data from the HLA-B27 transgenic rat model of spondyloarthritis; the growing list of other genes that have been found to be associated with AS; and other data on the pathogenesis of spondyloarthritis. Proposed directions for future research include expanded efforts to define similarities and differences among the B27 subtypes; further development of animal models; identifying the interactions of B27 with the products of other genes associated with AS; and continued investigation into the pathogenesis of spondyloarthritis.
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