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Maguire C, Crivello P, Fleischhauer K, Isaacson D, Casillas A, Kramer CS, Copley HC, Heidt S, Kosmoliaptsis V, Meneghini M, Gmeiner M, Schold J, Louzoun Y, Tambur AR. Qualitative, rather than quantitative, differences between HLA-DQ alleles affect HLA-DQ immunogenicity in organ transplantation. HLA 2024; 103:e15455. [PMID: 38575370 PMCID: PMC11003724 DOI: 10.1111/tan.15455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 03/04/2024] [Accepted: 03/12/2024] [Indexed: 04/06/2024]
Abstract
Prolonging the lifespan of transplanted organs is critical to combat the shortage of this life-saving resource. Chronic rejection, with irreversible demise of the allograft, is often caused by the development of donor-specific HLA antibodies. Currently, enumerating molecular (amino acid) mismatches between recipient and donor is promoted to identify patients at higher risk of developing HLA antibodies, for use in organ allocation, and immunosuppression-minimization strategies. We have counseled against the incorporation of such approaches into clinical use and hypothesized that not all molecular mismatches equally contribute to generation of donor-specific immune responses. Herein, we document statistical shortcomings in previous study design: for example, use of individuals who lack the ability to generate donor-specific-antibodies (HLA identical) as part of the negative cohort. We provide experimental evidence, using CRISPR-Cas9-edited cells, to rebut the claim that the HLAMatchmaker eplets represent "functional epitopes." We further used unique sub-cohorts of patients, those receiving an allograft with two HLA-DQ mismatches yet developing antibodies only to one mismatch (2MM1DSA), to interrogate differential immunogenicity. Our results demonstrate that mismatches of DQα05-heterodimers exhibit the highest immunogenicity. Additionally, we demonstrate that the DQα chain critically contributes to the overall qualities of DQ molecules. Lastly, our data proposes that an augmented risk to develop donor-specific HLA-DQ antibodies is dependent on qualitative (evolutionary and functional) divergence between recipient and donor, rather than the mere number of molecular mismatches. Overall, we propose an immunological mechanistic rationale to explain differential HLA-DQ immunogenicity, with potential ramifications for other pathological processes such as autoimmunity and infections.
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Affiliation(s)
- Chelsea Maguire
- Department of Surgery, Comprehensive Transplant Center; Northwestern University, Chicago, IL, USA. 60611
| | - Pietro Crivello
- Institute for Experimental Cellular Therapy, University Hospital Essen; Essen, Germany. 45127
| | - Katharina Fleischhauer
- Institute for Experimental Cellular Therapy, University Hospital Essen; Essen, Germany. 45127
- German Cancer Consortium (DKTK), partner site Essen/Düsseldorf; Essen, Germany. 45127
| | - Dylan Isaacson
- Department of Surgery, Comprehensive Transplant Center; Northwestern University, Chicago, IL, USA. 60611
| | - Aurora Casillas
- Department of Surgery, Comprehensive Transplant Center; Northwestern University, Chicago, IL, USA. 60611
| | - Cynthia S.M. Kramer
- Department of Immunology, Leiden University Medical Center; Netherlands. 2300-2334
| | - Hannah C. Copley
- Department of Surgery, University of Cambridge; Cambridge, United Kingdom. CB2 3AX
| | - Sebastian Heidt
- Department of Immunology, Leiden University Medical Center; Netherlands. 2300-2334
| | | | - Maria Meneghini
- Vall d’Hebron Institut de Recerca, Vall d’Hebron Hospital Universitari; Barcelona, Spain. 08035
| | - Michael Gmeiner
- Department of Economics, London School of Economics; London, United Kingdom. WC2A 2AE
| | - Jesse Schold
- Department of surgery, university of Colorado Anschutz Medical campus; Aurora, CO, USA. 80045
- Department of epidemiology, university of Colorado Anschutz Medical campus; Aurora, CO, USA. 80045
| | - Yoram Louzoun
- Department of mathematics Bar Ilan University; Ramat Gan, Israel. 5290002
| | - Anat R. Tambur
- Department of Surgery, Comprehensive Transplant Center; Northwestern University, Chicago, IL, USA. 60611
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Kramer CSM, Bezstarosti S, Franke-van Dijk MEI, Vergunst M, Roelen DL, Uyar-Mercankaya M, Voogt-Bakker KH, Heidt S. Antibody verification of HLA class I and class II eplets by human monoclonal HLA antibodies. HLA 2024; 103:e15345. [PMID: 38239050 DOI: 10.1111/tan.15345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 12/11/2023] [Accepted: 12/29/2023] [Indexed: 01/23/2024]
Abstract
In solid organ transplantation, formation of de novo donor-specific HLA antibodies is induced by mismatched eplets on donor HLA molecules. While several studies have shown a strong correlation between the number of eplet mismatches and inferior outcomes, not every eplet mismatch is immunogenic. Eplets are theoretically defined entities, necessitating formal proof that they can be recognised and bound by antibodies. This antibody verification is pivotal to ensure that clinically relevant eplets are considered in studies on molecular matching. Recombinant human HLA-specific monoclonal antibodies (mAbs) were generated from HLA-reactive B cell clones isolated from HLA immunised individuals using recombinant HLA molecules. Subsequently, the reactivity patterns of the mAbs obtained from single antigen bead assay were analysed using HLA-EMMA software to identify single or configurations of solvent accessible amino acids uniquely present on the reactive HLA alleles and were mapped to eplets. Two HLA class I and seven HLA class II-specific human mAbs were generated from four individuals. Extensive mAb reactivity analysis, led to antibody verification of three HLA-DR-specific eplets, and conversion of five eplets (one HLA-A, one HLA-B, two HLA-DR, and one HLA-DP), from provisionally verified to truly antibody-verified. Finally, one HLA-DQ-specific eplet was upgraded from level A2 to level A1 verification evidence. The generation of recombinant human HLA-specific mAbs with different specificities contributes significantly to the antibody verification of eplets and therefore is instrumental for implementation of eplet matching in the clinical setting.
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Affiliation(s)
- Cynthia S M Kramer
- Department of Immunology, Leiden University Medical Center, Leiden, The Netherlands
| | - Suzanne Bezstarosti
- Department of Immunology, Leiden University Medical Center, Leiden, The Netherlands
- Department of Nephrology, Leiden University Medical Center, Leiden, The Netherlands
| | | | - Manon Vergunst
- Department of Immunology, Leiden University Medical Center, Leiden, The Netherlands
| | - Dave L Roelen
- Department of Immunology, Leiden University Medical Center, Leiden, The Netherlands
| | | | - Kim H Voogt-Bakker
- Department of Immunology, Leiden University Medical Center, Leiden, The Netherlands
| | - Sebastiaan Heidt
- Department of Immunology, Leiden University Medical Center, Leiden, The Netherlands
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3
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Quon JC, Kaneta K, Fotiadis N, Menteer J, Lestz RM, Weisert M, Baxter-Lowe LA. HLA diversity in ethnic populations can affect detection of donor-specific antibodies by single antigen beads. Front Immunol 2023; 14:1287028. [PMID: 38077376 PMCID: PMC10701672 DOI: 10.3389/fimmu.2023.1287028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 11/02/2023] [Indexed: 12/18/2023] Open
Abstract
Introduction In solid-organ transplantation, human leukocyte antigen (HLA) donor-specific antibodies (DSA) are strongly associated with graft rejection, graft loss, and patient death. The predominant tests used for detecting HLA DSA before and after solid-organ transplantation are HLA single antigen bead (SAB) assays. However, SAB assays may not detect antibodies directed against HLA epitopes that are not represented in the SAB. The prevalence and potential impact of unrepresented HLA epitopes are expected to vary by ethnicity, but have not been thoroughly investigated. To address this knowledge gap, HLA allele frequencies from seven ethnic populations were compared with HLA proteins present in SAB products from two manufacturers to determine unrepresented HLA proteins. Materials Allele frequencies were obtained from the Common, Intermediate, and Well Documented HLA catalog v3.0, and frequencies of unrepresented HLA types were calculated. Next-generation sequencing was used to determine HLA types of 60 deceased solid-organ donors, and results were used to determine if their HLA-A, -B, -C, and -DRB1 proteins were not present in SAB reagents from two vendors. Unrepresented HLA proteins were compared with the most similar protein in SAB assays from either vendor and then visualized using modeling software to assess potential HLA epitopes. Results For the seven ethnic populations, 0.5% to 11.8% of each population had HLA proteins not included in SAB assays from one vendor. Non-European populations had greater numbers of unrepresented alleles. Among the deceased donors, 26.7% (16/60) had at least one unrepresented HLA-A, -B, -C, or -DRB1 protein. Structural modeling demonstrated that a subset of these had potential HLA epitopes that are solvent accessible amino acid mismatches and are likely to be accessible to B cell receptors. Discussion In conclusion, SAB assays cannot completely rule out the presence of HLA DSA. HLA epitopes not represented in those assays vary by ethnicity and should not be overlooked, especially in non-European populations. Allele-level HLA typing can help determine the potential for HLA antibodies that could evade detection.
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Affiliation(s)
- Justin C. Quon
- Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Kelli Kaneta
- Division of Nephrology, Children’s Hospital Los Angeles, Los Angeles, CA, United States
| | - Nicholas Fotiadis
- Department of Pathology and Laboratory Medicine, Children's Hospital Los Angeles, Los Angeles, CA, United States
| | - Jondavid Menteer
- Department of Pediatrics, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
- Division of Cardiology, Children’s Hospital Los Angeles, Los Angeles, CA, United States
| | - Rachel M. Lestz
- Division of Nephrology, Children’s Hospital Los Angeles, Los Angeles, CA, United States
- Department of Pediatrics, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Molly Weisert
- Department of Pediatrics, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
- Division of Cardiology, Children’s Hospital Los Angeles, Los Angeles, CA, United States
| | - Lee Ann Baxter-Lowe
- Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
- Department of Pathology and Laboratory Medicine, Children's Hospital Los Angeles, Los Angeles, CA, United States
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Kervella D, Torija A, Zúñiga JM, Bestard O. How to measure human leukocyte antigen-specific B cells. Curr Opin Organ Transplant 2023; 28:345-354. [PMID: 37678170 DOI: 10.1097/mot.0000000000001097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/09/2023]
Abstract
PURPOSE OF REVIEW The implementation of highly sensitive immune assays measuring anti-human leukocyte antigen (HLA) antibodies has modified alloimmune risk stratification and diagnosis of rejection. Nonetheless, anti-HLA antibodies represent the downstream effector mechanism of the B-cell response. Better characterizing the cellular components of the humoral immune response (including memory B cells (mBCs) and long-lived plasma cells) could help to further stratify the alloimmune risk stratification and enable discovery of new therapeutic targets. Several tests that characterize HLA-specific mBCs, either functionally or phenotypically, have been developed in the last years, showing promising applications as well as some limitations. RECENT FINDINGS Functional assays involving ex vivo polyclonal activation of mBC have been refined to allow the detection of HLA-specific mBC capable of producing anti-HLA Abs, using different and complementary detection platforms such as multiplex Fluorospot and single antigen bead assay on culture supernatants. Detection of circulating HLA-specific B cells by flow cytometry remains hindered by the very low frequency of HLA-specific mBC. SUMMARY Technological refinements have allowed the development of tests detecting HLA-specific mBC. Further evaluation of these assays in clinical trials, both for immune risk stratification and to assess treatment efficacy (desensitization strategies, rescue therapies for ABMR) are now urgently needed.
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Affiliation(s)
- Delphine Kervella
- Nephrology and Kidney Transplant Department
- Translational Nephrology and Kidney Transplant Research Laboratory, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain
| | - Alba Torija
- Nephrology and Kidney Transplant Department
- Translational Nephrology and Kidney Transplant Research Laboratory, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain
| | - Jose M Zúñiga
- Nephrology and Kidney Transplant Department
- Translational Nephrology and Kidney Transplant Research Laboratory, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain
| | - Oriol Bestard
- Nephrology and Kidney Transplant Department
- Translational Nephrology and Kidney Transplant Research Laboratory, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain
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Kleid L, Walter J, Vorstandlechner M, Schneider CP, Michel S, Kneidinger N, Irlbeck M, Wichmann C, Möhnle P, Humpe A, Kauke T, Dick A. Predictive value of molecular matching tools for the development of donor specific HLA-antibodies in patients undergoing lung transplantation. HLA 2023. [PMID: 37068792 DOI: 10.1111/tan.15068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 03/21/2023] [Accepted: 04/06/2023] [Indexed: 04/19/2023]
Abstract
Molecular matching is a new approach for virtual histocompatibility testing in organ transplantation. The aim of our study was to analyze whether the risk for de novo donor-specific HLA antibodies (dnDSA) after lung transplantation (LTX) can be predicted by molecular matching algorithms (MMA) and their combination. In this retrospective study we included 183 patients undergoing LTX at our center from 2012-2020. We monitored dnDSA development for 1 year. Eplet mismatches (epMM) using HLAMatchmaker were calculated and highly immunogenic eplets based on their ElliPro scores were identified. PIRCHE-II scores were calculated using PIRCHE-II algorithm (5- and 11-loci). We compared epMM and PIRCHE-II scores between patients with and without dnDSA using t-test and used ROC-curves to determine optimal cut-off values to categorize patients into four groups. We used logistic regression with AIC to compare the predictive value of PIRCHE-II, epMM, and their combination. In total 28.4% of patients developed dnDSA (n = 52), 12.5% class I dnDSA (n = 23), 24.6% class II dnDSA (n = 45), and 8.7% both class II and II dnDSA (n = 16). Mean epMMs (p-value = 0.005), mean highly immunogenic epMMs (p-value = 0.003), and PIRCHE-II (11-loci) (p = 0.01) were higher in patients with compared to without class II dnDSA. Patients with highly immunogenic epMMs above 30.5 and PIRCHE-II 11-loci above 560.0 were more likely to develop dnDSA (31.1% vs. 14.8%, p-value = 0.03). The logistic regression model including the grouping variable showed the best predictive value. MMA can support clinicians to identify patients at higher or lower risk for developing class II dnDSA and might be helpful tools for immunological risk assessment in LTX patients.
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Affiliation(s)
- Lisa Kleid
- Laboratory for Immunogenetics, Division of Transfusion Medicine, Cell Therapeutics and Haemostaseology, University Hospital, LMU Munich, Munich, Germany
- Division of Transfusion Medicine, Cell Therapeutics and Haemostaseology, University Hospital, LMU Munich, Munich, Germany
| | - Julia Walter
- Division of Thoracic Surgery, University Hospital, LMU Munich, Munich, Germany
- Comprehensive Pneumology Center Munich (CPC-M), German Center for Lung Research (DZL), Munich, Germany
- Department of Medicine V, University Hospital, LMU Munich, Munich, Germany
| | | | - Christian P Schneider
- Division of Thoracic Surgery, University Hospital, LMU Munich, Munich, Germany
- Comprehensive Pneumology Center Munich (CPC-M), German Center for Lung Research (DZL), Munich, Germany
| | - Sebastian Michel
- Comprehensive Pneumology Center Munich (CPC-M), German Center for Lung Research (DZL), Munich, Germany
- Department of Cardiac Surgery, University Hospital, LMU Munich, Munich, Germany
| | - Nikolaus Kneidinger
- Comprehensive Pneumology Center Munich (CPC-M), German Center for Lung Research (DZL), Munich, Germany
- Department of Medicine V, University Hospital, LMU Munich, Munich, Germany
| | - Michael Irlbeck
- Department of Anesthesiology, University Hospital, LMU Munich, Munich, Germany
| | - Christian Wichmann
- Division of Transfusion Medicine, Cell Therapeutics and Haemostaseology, University Hospital, LMU Munich, Munich, Germany
| | - Patrick Möhnle
- Division of Transfusion Medicine, Cell Therapeutics and Haemostaseology, University Hospital, LMU Munich, Munich, Germany
| | - Andreas Humpe
- Division of Transfusion Medicine, Cell Therapeutics and Haemostaseology, University Hospital, LMU Munich, Munich, Germany
| | - Teresa Kauke
- Division of Thoracic Surgery, University Hospital, LMU Munich, Munich, Germany
- Transplantation Center, University Hospital, LMU Munich, Munich, Germany
| | - Andrea Dick
- Laboratory for Immunogenetics, Division of Transfusion Medicine, Cell Therapeutics and Haemostaseology, University Hospital, LMU Munich, Munich, Germany
- Division of Transfusion Medicine, Cell Therapeutics and Haemostaseology, University Hospital, LMU Munich, Munich, Germany
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6
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Meng T, Bezstarosti S, Singh U, Yap M, Scott L, Petrosyan N, Quiroz F, Eps NV, Hui EKW, Suh D, Zhu Q, Pei R, Kramer CSM, Claas FHJ, Lowe D, Heidt S. Site-directed mutagenesis of HLA molecules reveals the functional epitope of a human HLA-A1/A36-specific monoclonal antibody. HLA 2023; 101:138-142. [PMID: 36401817 PMCID: PMC10099858 DOI: 10.1111/tan.14895] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 10/13/2022] [Accepted: 11/18/2022] [Indexed: 11/21/2022]
Abstract
Eplet 44KM is currently listed in the HLA Epitope Registry but does not adhere to the eplet definition of an amino acid configuration within a 3.5 Å radius. Eplet 44KM has been previously redefined to the antibody-verified reactivity pattern 44K/150V/158V, based on reactivity analysis of monoclonal antibody VDK1D12. Since the three residues are always simultaneously present on common HLA alleles, methods to define which residue is crucial for antibody-induction and binding are limited. In this proof-of-concept study, we performed site-directed mutagenesis to narrow down the antibody-verified reactivity pattern 44K/150V/158V to a single amino acid and defined 44K as the eplet or functional epitope of mAb VDK1D12.
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Affiliation(s)
- Tina Meng
- Department of Research and Development, One Lambda, Inc. (A Part of Thermo Fisher Scientific Inc.), West Hills, California, USA
| | - Suzanne Bezstarosti
- Department of Immunology, Leiden University Medical Center, Leiden, The Netherlands.,Department of Internal Medicine (Nephrology), Leiden University Medical Center, Leiden, The Netherlands
| | - Ujjwala Singh
- Department of Research and Development, One Lambda, Inc. (A Part of Thermo Fisher Scientific Inc.), West Hills, California, USA
| | - Michelle Yap
- Department of Research and Development, One Lambda, Inc. (A Part of Thermo Fisher Scientific Inc.), West Hills, California, USA
| | - Laura Scott
- Department of Research and Development, One Lambda, Inc. (A Part of Thermo Fisher Scientific Inc.), West Hills, California, USA
| | - Naiiry Petrosyan
- Department of Research and Development, One Lambda, Inc. (A Part of Thermo Fisher Scientific Inc.), West Hills, California, USA
| | - Fred Quiroz
- Department of Research and Development, One Lambda, Inc. (A Part of Thermo Fisher Scientific Inc.), West Hills, California, USA
| | - Ned Van Eps
- Department of Research and Development, One Lambda, Inc. (A Part of Thermo Fisher Scientific Inc.), West Hills, California, USA
| | - Eric Ka-Wai Hui
- Department of Research and Development, One Lambda, Inc. (A Part of Thermo Fisher Scientific Inc.), West Hills, California, USA
| | - David Suh
- Department of Research and Development, One Lambda, Inc. (A Part of Thermo Fisher Scientific Inc.), West Hills, California, USA
| | - Quansheng Zhu
- Department of Research and Development, One Lambda, Inc. (A Part of Thermo Fisher Scientific Inc.), West Hills, California, USA
| | - Rui Pei
- Department of Research and Development, One Lambda, Inc. (A Part of Thermo Fisher Scientific Inc.), West Hills, California, USA
| | - Cynthia S M Kramer
- Department of Immunology, Leiden University Medical Center, Leiden, The Netherlands
| | - Frans H J Claas
- Department of Immunology, Leiden University Medical Center, Leiden, The Netherlands
| | - David Lowe
- Department of Research and Development, One Lambda, Inc. (A Part of Thermo Fisher Scientific Inc.), West Hills, California, USA
| | - Sebastiaan Heidt
- Department of Immunology, Leiden University Medical Center, Leiden, The Netherlands
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7
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Niemann M, Matern BM, Spierings E. Snowflake: A deep learning-based human leukocyte antigen matching algorithm considering allele-specific surface accessibility. Front Immunol 2022; 13:937587. [PMID: 35967374 PMCID: PMC9372366 DOI: 10.3389/fimmu.2022.937587] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 07/11/2022] [Indexed: 12/12/2022] Open
Abstract
Histocompatibility in solid-organ transplantation has a strong impact on long-term graft survival. Although recent advances in matching of both B-cell epitopes and T-cell epitopes have improved understanding of allorecognition, the immunogenic determinants are still not fully understood. We hypothesized that HLA solvent accessibility is allele-specific, thus supporting refinement of HLA B-cell epitope prediction. We developed a computational pipeline named Snowflake to calculate solvent accessibility of HLA Class I proteins for deposited HLA crystal structures, supplemented by constructed HLA structures through the AlphaFold protein folding predictor and peptide binding predictions of the APE-Gen docking framework. This dataset trained a four-layer long short-term memory bidirectional recurrent neural network, which in turn inferred solvent accessibility of all known HLA Class I proteins. We extracted 676 HLA Class-I experimental structures from the Protein Data Bank and supplemented it by 37 Class-I alleles for which structures were predicted. For each of the predicted structures, 10 known binding peptides as reported by the Immune Epitope DataBase were rendered into the binding groove. Although HLA Class I proteins predominantly are folded similarly, we found higher variation in root mean square difference of solvent accessibility between experimental structures of different HLAs compared to structures with identical amino acid sequence, suggesting HLA’s solvent accessible surface is protein specific. Hence, residues may be surface-accessible on e.g. HLA-A*02:01, but not on HLA-A*01:01. Mapping these data to antibody-verified epitopes as defined by the HLA Epitope Registry reveals patterns of (1) consistently accessible residues, (2) only subsets of an epitope’s residues being consistently accessible and (3) varying surface accessibility of residues of epitopes. Our data suggest B-cell epitope definitions can be refined by considering allele-specific solvent-accessibility, rather than aggregating HLA protein surface maps by HLA class or locus. To support studies on epitope analyses in organ transplantation, the calculation of donor-allele-specific solvent-accessible amino acid mismatches was implemented as a cloud-based web service.
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Affiliation(s)
- Matthias Niemann
- Research and Development, PIRCHE AG, Berlin, Germany
- *Correspondence: Matthias Niemann,
| | - Benedict M. Matern
- Center for Translational Immunology, University Medical Center, Utrecht, Netherlands
| | - Eric Spierings
- Center for Translational Immunology, University Medical Center, Utrecht, Netherlands
- Central Diagnostic Laboratory, University Medical Center, Utrecht, Netherlands
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8
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Osoegawa K, Marsh SGE, Holdsworth R, Heidt S, Fischer G, Murphey C, Maiers M, Fernández Viňa MA. A new strategy for systematically classifying HLA alleles into serological specificities. HLA 2022; 100:193-231. [PMID: 35538616 DOI: 10.1111/tan.14662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 04/30/2022] [Accepted: 05/08/2022] [Indexed: 11/30/2022]
Abstract
HLA serological specificities were defined by the reactivity of HLA molecules with sets of sera and monoclonal antibodies. Many recently identified alleles defined by molecular typing lack their serotype assignment. We surveyed the literature describing the correlation of the reactivity of serologic reagents with AA residues. 20 - 25 AA residues determining epitopes (DEP) that correlated with 82 WHO serologic specificities were identified for HLA class I loci. Thirteen DEP each located in the beta-1 domains that correlated with 24 WHO serologic specificities were identified for HLA-DRB1 and -DQB1 loci. The designation of possible HLA-DPB1, -DQA1, -DPA1, and additional serological specificities that result from epitopes defined by residues located at both -DQA1 and -DQB1 subunits were also examined. HATS software was developed for automated serotype assignments to HLA alleles in one of the three hierarchical matching criteria: 1) all DEP (FULL); 2) selected DEP specific to each serological specificities (SEROTYPE); 3) one AA mismatch with one or more SEROTYPES (INCOMPLETE). Results were validated by evaluating the alleles whose serotypes do not correspond to the first field of the allele name listed in the HLA dictionary. Additional 85 and 21 DEP patterns that do not correspond to any WHO serologic specificities for common HLA class I and DRB1 alleles were identified, respectively. A comprehensive antibody identification panel would allow for accurate unacceptable antigen listing and compatibility predictions in solid organ transplantations. We propose that antibody-screening panels should include all serologic specificities identified in this study. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Kazutoyo Osoegawa
- Histocompatibility and Immunogenetics Laboratory, Stanford Blood Center, Palo Alto, CA, USA
| | - Steven G E Marsh
- Anthony Nolan Research Institute & UCL Cancer Institute, Royal Free Campus, London, United Kingdom
| | | | - Sebastiaan Heidt
- Department of Immunology, Leiden University Medical Center, Leiden, the Netherlands
| | - Gottfried Fischer
- Department of Blood Group Serology and Transfusion Medicine, Medical University of Vienna, Vienna, Austria
| | - Cathi Murphey
- Histocompatibility and Immunogenetics Laboratory at Southwest Immunodiagnostics, Inc, San Antonio, TX, USA
| | - Martin Maiers
- Innovation, National Marrow Donor Program, Minneapolis, MN, USA
| | - Marcelo A Fernández Viňa
- Histocompatibility and Immunogenetics Laboratory, Stanford Blood Center, Palo Alto, CA, USA.,Department of Pathology, Stanford University School of Medicine, Palo Alto, CA, USA
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9
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Bezstarosti S, Bakker KH, Kramer CSM, de Fijter JW, Reinders MEJ, Mulder A, Claas FHJ, Heidt S. A Comprehensive Evaluation of the Antibody-Verified Status of Eplets Listed in the HLA Epitope Registry. Front Immunol 2022; 12:800946. [PMID: 35154076 PMCID: PMC8831796 DOI: 10.3389/fimmu.2021.800946] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Accepted: 12/30/2021] [Indexed: 01/09/2023] Open
Abstract
Matching strategies based on HLA eplets instead of HLA antigens in solid organ transplantation may not only increase the donor pool for highly sensitized patients, but also decrease the incidence of de novo donor-specific antibody formation. However, since not all eplets are equally capable of inducing an immune response, antibody verification is needed to confirm their ability to be bound by antibodies, such that only clinically relevant eplets are considered. The HLA Epitope Registry has documented all theoretically defined HLA eplets along with their antibody verification status and has been the foundation for many clinical studies investigating eplet mismatch in transplantation. The verification methods for eplets in the Registry range from polyclonal sera from multi- and uni-parous women to murine and human monoclonal antibodies (mAbs), and antibodies purified by adsorption and elution from sera of HLA immunized individuals. The classification of antibody verification based on different methods for validation is problematic, since not all approaches represent the same level of evidence. In this study, we introduce a classification system to evaluate the level of evidence for the antibody-verified status of all eplets in the HLA Epitope Registry. We demonstrate that for a considerable number of eplets, the antibody-verified status is solely based on polyclonal serum reactivity of multiparous women or on reactivity of murine mAbs. Furthermore, we noted that a substantial proportion of patient sera analyses and human mAb data presented in the HLA Epitope Registry Database has never been published in a peer-reviewed journal. Therefore, we tested several unpublished human HLA-specific mAbs by luminex single antigen beads assay to analyze their HLA reactivity for eplet antibody verification. Although the majority of analyzed mAbs indeed verified their assigned eplets, this was not the case for a number of eplets. This comprehensive overview of evidence for antibody verification of eplets in the HLA Epitope Registry is instrumental for future investigations towards eplet immunogenicity and clinical studies considering antibody-verified eplet mismatch in transplantation and warrants further standardization of antibody verification using high quality data.
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Affiliation(s)
- Suzanne Bezstarosti
- Department of Immunology, Leiden University Medical Center, Leiden, Netherlands.,Department of Internal Medicine (Nephrology), Leiden University Medical Center, Leiden, Netherlands
| | - Kim H Bakker
- Department of Immunology, Leiden University Medical Center, Leiden, Netherlands
| | - Cynthia S M Kramer
- Department of Immunology, Leiden University Medical Center, Leiden, Netherlands
| | - Johan W de Fijter
- Department of Internal Medicine (Nephrology), Leiden University Medical Center, Leiden, Netherlands
| | - Marlies E J Reinders
- Department of Internal Medicine, Erasmus Medical Center Transplantation Institute, University Medical Center Rotterdam, Rotterdam, Netherlands
| | - Arend Mulder
- Department of Immunology, Leiden University Medical Center, Leiden, Netherlands
| | - Frans H J Claas
- Department of Immunology, Leiden University Medical Center, Leiden, Netherlands.,Eurotransplant Reference Laboratory, Leiden, Netherlands
| | - Sebastiaan Heidt
- Department of Immunology, Leiden University Medical Center, Leiden, Netherlands.,Eurotransplant Reference Laboratory, Leiden, Netherlands
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