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Duru AD, Sun R, Allerbring EB, Chadderton J, Kadri N, Han X, Peqini K, Uchtenhagen H, Madhurantakam C, Pellegrino S, Sandalova T, Nygren PÅ, Turner SJ, Achour A. Tuning antiviral CD8 T-cell response via proline-altered peptide ligand vaccination. PLoS Pathog 2020; 16:e1008244. [PMID: 32365082 PMCID: PMC7224568 DOI: 10.1371/journal.ppat.1008244] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 05/14/2020] [Accepted: 04/11/2020] [Indexed: 12/16/2022] Open
Abstract
Viral escape from CD8+ cytotoxic T lymphocyte responses correlates with disease progression and represents a significant challenge for vaccination. Here, we demonstrate that CD8+ T cell recognition of the naturally occurring MHC-I-restricted LCMV-associated immune escape variant Y4F is restored following vaccination with a proline-altered peptide ligand (APL). The APL increases MHC/peptide (pMHC) complex stability, rigidifies the peptide and facilitates T cell receptor (TCR) recognition through reduced entropy costs. Structural analyses of pMHC complexes before and after TCR binding, combined with biophysical analyses, revealed that although the TCR binds similarly to all complexes, the p3P modification alters the conformations of a very limited amount of specific MHC and peptide residues, facilitating efficient TCR recognition. This approach can be easily introduced in peptides restricted to other MHC alleles, and can be combined with currently available and future vaccination protocols in order to prevent viral immune escape.
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Affiliation(s)
- Adil Doganay Duru
- Science for Life Laboratory, Department of Medicine Solna, Karolinska Institute, and Division of Infectious Diseases, Karolinska University Hospital, Solna, Stockholm, Sweden
- NSU Cell Therapy Institute & Dr. Kiran C. Patel College of Allopathic Medicine, Nova Southeastern University, Fort Lauderdale, Florida, United States of America
| | - Renhua Sun
- Science for Life Laboratory, Department of Medicine Solna, Karolinska Institute, and Division of Infectious Diseases, Karolinska University Hospital, Solna, Stockholm, Sweden
| | - Eva B. Allerbring
- Science for Life Laboratory, Department of Medicine Solna, Karolinska Institute, and Division of Infectious Diseases, Karolinska University Hospital, Solna, Stockholm, Sweden
| | - Jesseka Chadderton
- Department of Microbiology, Biomedical Discovery Institute, Monash University, Clayton, Australia
| | - Nadir Kadri
- Science for Life Laboratory, Department of Medicine Solna, Karolinska Institute, and Division of Infectious Diseases, Karolinska University Hospital, Solna, Stockholm, Sweden
| | - Xiao Han
- Science for Life Laboratory, Department of Medicine Solna, Karolinska Institute, and Division of Infectious Diseases, Karolinska University Hospital, Solna, Stockholm, Sweden
| | - Kaliroi Peqini
- DISFARM, Dipartimento di Scienze Farmaceutiche, Sezinone Chimica Generale e Organica, Università degli Studi, Milano, Italy
| | - Hannes Uchtenhagen
- Science for Life Laboratory, Department of Medicine Solna, Karolinska Institute, and Division of Infectious Diseases, Karolinska University Hospital, Solna, Stockholm, Sweden
| | - Chaithanya Madhurantakam
- Science for Life Laboratory, Department of Medicine Solna, Karolinska Institute, and Division of Infectious Diseases, Karolinska University Hospital, Solna, Stockholm, Sweden
- Structural and Molecular Biology Laboratory, Department of Biotechnology, TERI, School of Advanced Studies, New Delhi, India
| | - Sara Pellegrino
- DISFARM, Dipartimento di Scienze Farmaceutiche, Sezinone Chimica Generale e Organica, Università degli Studi, Milano, Italy
| | - Tatyana Sandalova
- Science for Life Laboratory, Department of Medicine Solna, Karolinska Institute, and Division of Infectious Diseases, Karolinska University Hospital, Solna, Stockholm, Sweden
| | - Per-Åke Nygren
- Division of Protein Engineering, Department of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, AlbaNova University Center, Royal Institute of Technology, Stockholm, Sweden
| | - Stephen J. Turner
- Department of Microbiology, Biomedical Discovery Institute, Monash University, Clayton, Australia
| | - Adnane Achour
- Science for Life Laboratory, Department of Medicine Solna, Karolinska Institute, and Division of Infectious Diseases, Karolinska University Hospital, Solna, Stockholm, Sweden
- * E-mail:
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Hafstrand I, Doorduijn EM, Sun R, Talyzina A, Sluijter M, Pellegrino S, Sandalova T, Duru AD, van Hall T, Achour A. The Immunogenicity of a Proline-Substituted Altered Peptide Ligand toward the Cancer-Associated TEIPP Neoepitope Trh4 Is Unrelated to Complex Stability. THE JOURNAL OF IMMUNOLOGY 2018; 200:2860-2868. [PMID: 29507106 DOI: 10.4049/jimmunol.1700228] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 02/07/2018] [Indexed: 01/05/2023]
Abstract
Human cancers frequently display defects in Ag processing and presentation allowing for immune evasion, and they therefore constitute a significant challenge for T cell-based immunotherapy. We have previously demonstrated that the antigenicity of tumor-associated Ags can be significantly enhanced through unconventional residue modifications as a novel tool for MHC class I (MHC-I)-based immunotherapy approaches. We have also previously identified a novel category of cancer neo-epitopes, that is, T cell epitopes associated with impaired peptide processing (TEIPP), that are selectively presented by MHC-I on cells lacking the peptide transporter TAP. In this study, we demonstrate that substitution of the nonanchoring position 3 into a proline residue of the first identified TEIPP peptide, the murine Trh4, results in significantly enhanced recognition by antitumor CTLs toward the wild-type epitope. Although higher immunogenicity has in most cases been associated with increased MHC/peptide complex stability, our results demonstrate that the overall stability of H-2Db in complex with the highly immunogenic altered peptide ligand Trh4-p3P is significantly reduced compared with wild-type H-2Db/Trh4. Comparison of the crystal structures of the H-2Db/Trh4-p3P and H-2Db/Trh4 complexes revealed that the conformation of the nonconventional methionine anchor residue p5M is altered, deleting its capacity to form adequate sulfur-π interactions with H-2Db residues, thus reducing the overall longevity of the complex. Collectively, our results indicate that vaccination with Thr4-p3P significantly enhances T cell recognition of targets presenting the wild-type TEIPP epitope and that higher immunogenicity is not necessarily directly related to MHC/peptide complex stability, opening for the possibility to design novel peptide vaccines with reduced MHC/peptide complex stability.
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Affiliation(s)
- Ida Hafstrand
- Science for Life Laboratory, Department of Medicine Solna, Karolinska Institutet, 17165 Stockholm, Sweden.,Department of Infectious Diseases, Karolinska University Hospital, Solna, 17176 Stockholm, Sweden
| | - Elien M Doorduijn
- Medical Oncology, Leiden University Medical Center, 2333 ZA Leiden, the Netherlands
| | - Renhua Sun
- Science for Life Laboratory, Department of Medicine Solna, Karolinska Institutet, 17165 Stockholm, Sweden.,Department of Infectious Diseases, Karolinska University Hospital, Solna, 17176 Stockholm, Sweden
| | - Anna Talyzina
- Science for Life Laboratory, Department of Medicine Solna, Karolinska Institutet, 17165 Stockholm, Sweden.,Department of Infectious Diseases, Karolinska University Hospital, Solna, 17176 Stockholm, Sweden
| | - Marjolein Sluijter
- Medical Oncology, Leiden University Medical Center, 2333 ZA Leiden, the Netherlands
| | - Sara Pellegrino
- Department of Pharmaceutical Science, General and Organic Chemistry Section, University of Milan, 20133 Milan, Italy
| | - Tatyana Sandalova
- Science for Life Laboratory, Department of Medicine Solna, Karolinska Institutet, 17165 Stockholm, Sweden.,Department of Infectious Diseases, Karolinska University Hospital, Solna, 17176 Stockholm, Sweden
| | - Adil Doganay Duru
- Cell Therapy Institute, Nova Southeastern University, Fort Lauderdale, FL 33314; and.,College of Allopathic Medicine, Nova Southeastern University, Fort Lauderdale, FL 33328
| | - Thorbald van Hall
- Medical Oncology, Leiden University Medical Center, 2333 ZA Leiden, the Netherlands;
| | - Adnane Achour
- Science for Life Laboratory, Department of Medicine Solna, Karolinska Institutet, 17165 Stockholm, Sweden; .,Department of Infectious Diseases, Karolinska University Hospital, Solna, 17176 Stockholm, Sweden
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Hafstrand I, Doorduijn EM, Duru AD, Buratto J, Oliveira CC, Sandalova T, van Hall T, Achour A. The MHC Class I Cancer-Associated Neoepitope Trh4 Linked with Impaired Peptide Processing Induces a Unique Noncanonical TCR Conformer. THE JOURNAL OF IMMUNOLOGY 2016; 196:2327-34. [PMID: 26800871 DOI: 10.4049/jimmunol.1502249] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 12/18/2015] [Indexed: 11/19/2022]
Abstract
MHC class I downregulation represents a significant challenge for successful T cell-based immunotherapy. T cell epitopes associated with impaired peptide processing (TEIPP) constitute a novel category of immunogenic Ags that are selectively presented on transporter associated with Ag processing-deficient cells. The TEIPP neoepitopes are CD8 T cell targets, derived from nonmutated self-proteins that might be exploited to prevent immune escape. In this study, the crystal structure of H-2D(b) in complex with the first identified TEIPP Ag (MCLRMTAVM) derived from the Trh4 protein has been determined to 2.25 Å resolution. In contrast to prototypic H-2D(b) peptides, Trh4 takes a noncanonical peptide-binding pattern with extensive sulfur-π interactions that contribute to the overall complex stability. Importantly, the noncanonical methionine at peptide position 5 acts as a main anchor, altering only the conformation of the H-2D(b) residues Y156 and H155 and thereby forming a unique MHC/peptide conformer that is essential for recognition by TEIPP-specific T cells. Substitution of peptide residues p2C and p5M to the conservative α-aminobutyric acid and norleucine, respectively, significantly reduced complex stability, without altering peptide conformation or T cell recognition. In contrast, substitution of p5M to a conventional asparagine abolished recognition by the H-2D(b)/Trh4-specific T cell clone LnB5. We anticipate that the H-2D(b)/Trh4 complex represents the first example, to our knowledge, of a broader repertoire of alternative MHC class I binders.
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Affiliation(s)
- Ida Hafstrand
- Science for Life Laboratory, Department of Medicine, Solna, Karolinska Institutet, SE-10450 Stockholm, Sweden; and
| | - Elien M Doorduijn
- Clinical Oncology, Leiden University Medical Center, Leiden 2333 ZA, the Netherlands
| | - Adil Doganay Duru
- Science for Life Laboratory, Department of Medicine, Solna, Karolinska Institutet, SE-10450 Stockholm, Sweden; and
| | - Jeremie Buratto
- Science for Life Laboratory, Department of Medicine, Solna, Karolinska Institutet, SE-10450 Stockholm, Sweden; and
| | | | - Tatyana Sandalova
- Science for Life Laboratory, Department of Medicine, Solna, Karolinska Institutet, SE-10450 Stockholm, Sweden; and
| | - Thorbald van Hall
- Clinical Oncology, Leiden University Medical Center, Leiden 2333 ZA, the Netherlands
| | - Adnane Achour
- Science for Life Laboratory, Department of Medicine, Solna, Karolinska Institutet, SE-10450 Stockholm, Sweden; and
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Madura F, Rizkallah PJ, Holland CJ, Fuller A, Bulek A, Godkin AJ, Schauenburg AJ, Cole DK, Sewell AK. Structural basis for ineffective T-cell responses to MHC anchor residue-improved "heteroclitic" peptides. Eur J Immunol 2015; 45:584-91. [PMID: 25471691 PMCID: PMC4357396 DOI: 10.1002/eji.201445114] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2014] [Revised: 10/03/2014] [Accepted: 11/26/2014] [Indexed: 12/11/2022]
Abstract
MHC anchor residue-modified "heteroclitic" peptides have been used in many cancer vaccine trials and often induce greater immune responses than the wild-type peptide. The best-studied system to date is the decamer MART-1/Melan-A26-35 peptide, EAAGIGILTV, where the natural alanine at position 2 has been modified to leucine to improve human leukocyte antigen (HLA)-A*0201 anchoring. The resulting ELAGIGILTV peptide has been used in many studies. We recently showed that T cells primed with the ELAGIGILTV peptide can fail to recognize the natural tumor-expressed peptide efficiently, thereby providing a potential molecular reason for why clinical trials of this peptide have been unsuccessful. Here, we solved the structure of a TCR in complex with HLA-A*0201-EAAGIGILTV peptide and compared it with its heteroclitic counterpart , HLA-A*0201-ELAGIGILTV. The data demonstrate that a suboptimal anchor residue at position 2 enables the TCR to "pull" the peptide away from the MHC binding groove, facilitating extra contacts with both the peptide and MHC surface. These data explain how a TCR can distinguish between two epitopes that differ by only a single MHC anchor residue and demonstrate how weak MHC anchoring can enable an induced-fit interaction with the TCR. Our findings constitute a novel demonstration of the extreme sensitivity of the TCR to minor alterations in peptide conformation.
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MESH Headings
- Alanine/chemistry
- Alanine/genetics
- Amino Acid Sequence
- Amino Acid Substitution
- Crystallography, X-Ray
- Epitopes, T-Lymphocyte/genetics
- Epitopes, T-Lymphocyte/immunology
- Epitopes, T-Lymphocyte/metabolism
- Escherichia coli/genetics
- Escherichia coli/metabolism
- Gene Expression
- HLA-A2 Antigen/chemistry
- HLA-A2 Antigen/genetics
- HLA-A2 Antigen/immunology
- Humans
- Leucine/chemistry
- Leucine/genetics
- MART-1 Antigen/chemistry
- MART-1 Antigen/genetics
- MART-1 Antigen/immunology
- Models, Molecular
- Molecular Sequence Data
- Peptides/chemistry
- Peptides/genetics
- Peptides/immunology
- Protein Binding
- Protein Interaction Domains and Motifs
- Receptors, Antigen, T-Cell, alpha-beta/chemistry
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Antigen, T-Cell, alpha-beta/immunology
- Recombinant Proteins/chemistry
- Recombinant Proteins/genetics
- Recombinant Proteins/immunology
- T-Lymphocytes, Cytotoxic/cytology
- T-Lymphocytes, Cytotoxic/immunology
- T-Lymphocytes, Cytotoxic/metabolism
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Affiliation(s)
- Florian Madura
- Division of Infection and Immunity, Cardiff University School of MedicineHeath Park, Cardiff, UK
| | - Pierre J Rizkallah
- Division of Infection and Immunity, Cardiff University School of MedicineHeath Park, Cardiff, UK
| | - Christopher J Holland
- Division of Infection and Immunity, Cardiff University School of MedicineHeath Park, Cardiff, UK
| | - Anna Fuller
- Division of Infection and Immunity, Cardiff University School of MedicineHeath Park, Cardiff, UK
| | - Anna Bulek
- Division of Infection and Immunity, Cardiff University School of MedicineHeath Park, Cardiff, UK
| | - Andrew J Godkin
- Division of Infection and Immunity, Cardiff University School of MedicineHeath Park, Cardiff, UK
| | - Andrea J Schauenburg
- Division of Infection and Immunity, Cardiff University School of MedicineHeath Park, Cardiff, UK
| | - David K Cole
- Division of Infection and Immunity, Cardiff University School of MedicineHeath Park, Cardiff, UK
| | - Andrew K Sewell
- Division of Infection and Immunity, Cardiff University School of MedicineHeath Park, Cardiff, UK
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González FE, Ramírez M, Allerbring EB, Fasching N, Lundqvist A, Poschke I, Achour A, Salazar-Onfray F. Melanocortin 1 Receptor-derived peptides are efficiently recognized by cytotoxic T lymphocytes from melanoma patients. Immunobiology 2013; 219:189-97. [PMID: 24192537 DOI: 10.1016/j.imbio.2013.10.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 09/10/2013] [Accepted: 10/03/2013] [Indexed: 11/28/2022]
Abstract
BACKGROUND Melanocortin 1 Receptor (MC1R) is expressed in a majority of melanoma biopsies and cell lines. We previously demonstrated that three hydrophobic low-affinity HLA-A2-restricted MC1R-derived peptides: MC1R291-298, MC1R244-252 and MC1R283-291 can elicit cytotoxic T-lymphocytes (CTL) responses from normal donor peripheral blood lymphocytes (PBL). Moreover, peptide-specific CTL recognized a panel of MHC-matched melanomas, demonstrating that human melanoma cell lines naturally present MC1R epitopes. However, the natural presence of MC1R-specific T cells in melanoma patient's tumour and blood remains unknown. METHODS The presence of anti-MC1R specific CD8(+) T cells was established in a population of melanoma-specific T cells derived from peripheral blood mononuclear cells (PBMC) and tumour-infiltrating lymphocytes (TIL) from HLA-A2(+) melanoma patients. RESULTS CTLs specific for the three MC1R-derived peptides that lysed allogeneic HLA-A2(+)MC1R(+) melanomas were elicited from PBMC, demonstrating the existence of an anti-MC1R T cell repertoire in melanoma patients. Moreover, TILs also recognized MC1R epitopes and HLA-A2(+) melanoma cell lines. Finally, HLA-A2/MC1R244-specific CD8(+) T cell clones derived from TILs and a subset of MC1R291 specific TILs were identified using HLA-A2/MC1R tetramers. CONCLUSION Our results demonstrate that MC1R-derived peptides are common immunogenic epitopes for melanoma-specific CTLs and TILs, and may thus be useful for the development of anti-melanoma immunotherapy.
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Affiliation(s)
- Fermín E González
- Millennium Institute on Immunology and Immunotherapy, Faculty of Medicine, University of Chile, 8380453 Santiago, Chile; Science for Life Laboratory, Centre for Infectious Medicine (CIM), Department of Medicine, Karolinska University Hospital Huddinge, Karolinska Institute, Stockholm, Sweden; Department of Conservative Dentistry, Faculty of Dentistry, University of Chile, 8380492 Santiago, Chile
| | - Marcos Ramírez
- Millennium Institute on Immunology and Immunotherapy, Faculty of Medicine, University of Chile, 8380453 Santiago, Chile
| | - Eva B Allerbring
- Science for Life Laboratory, Centre for Infectious Medicine (CIM), Department of Medicine, Karolinska University Hospital Huddinge, Karolinska Institute, Stockholm, Sweden
| | - Nina Fasching
- Science for Life Laboratory, Centre for Infectious Medicine (CIM), Department of Medicine, Karolinska University Hospital Huddinge, Karolinska Institute, Stockholm, Sweden
| | - Andreas Lundqvist
- Department of Oncology and Pathology, Cancer Centre Karolinska (R8:01), Karolinska Institute, Stockholm, Sweden
| | - Isabel Poschke
- Division of Molecular Oncology of Gastrointestinal Tumors, German Cancer Research Center, Heidelberg, Germany
| | - Adnane Achour
- Science for Life Laboratory, Centre for Infectious Medicine (CIM), Department of Medicine, Karolinska University Hospital Huddinge, Karolinska Institute, Stockholm, Sweden
| | - Flavio Salazar-Onfray
- Millennium Institute on Immunology and Immunotherapy, Faculty of Medicine, University of Chile, 8380453 Santiago, Chile.
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Chen S, Li Y, Depontieu FR, McMiller TL, English AM, Shabanowitz J, Kos F, Sidney J, Sette A, Rosenberg SA, Hunt DF, Mariuzza RA, Topalian SL. Structure-based design of altered MHC class II-restricted peptide ligands with heterogeneous immunogenicity. THE JOURNAL OF IMMUNOLOGY 2013; 191:5097-106. [PMID: 24108701 DOI: 10.4049/jimmunol.1300467] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Insights gained from characterizing MHC-peptide-TCR interactions have held the promise that directed structural modifications can have predictable functional consequences. The ability to manipulate T cell reactivity synthetically or through genetic engineering might thus be translated into new therapies for common diseases such as cancer and autoimmune disorders. In the current study, we determined the crystal structure of HLA-DR4 in complex with the nonmutated dominant gp100 epitope gp10044-59, associated with many melanomas. Altered peptide ligands (APLs) were designed to enhance MHC binding and hence T cell recognition of gp100 in HLA-DR4(+) melanoma patients. Increased MHC binding of several APLs was observed, validating this approach biochemically. Nevertheless, heterogeneous preferences of CD4(+) T cells from several HLA-DR4(+) melanoma patients for different gp100 APLs suggested highly variable TCR usage, even among six patients who had been vaccinated against the wild-type gp100 peptide. This heterogeneity prevented the selection of an APL candidate for developing an improved generic gp100 vaccine in melanoma. Our results are consistent with the idea that even conservative changes in MHC anchor residues may result in subtle, yet crucial, effects on peptide contacts with the TCR or on peptide dynamics, such that alterations intended to enhance immunogenicity may be unpredictable or counterproductive. They also underscore a critical knowledge gap that needs to be filled before structural and in vitro observations can be used reliably to devise new immunotherapies for cancer and other disorders.
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Affiliation(s)
- Shuming Chen
- Department of Surgery, Johns Hopkins University School of Medicine and the Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD 21287
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Sulfamethoxazole induces a switch mechanism in T cell receptors containing TCRVβ20-1, altering pHLA recognition. PLoS One 2013; 8:e76211. [PMID: 24116097 PMCID: PMC3792127 DOI: 10.1371/journal.pone.0076211] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Accepted: 08/21/2013] [Indexed: 11/19/2022] Open
Abstract
T cell receptors (TCR) containing Vβ20-1 have been implicated in a wide range of T cell mediated disease and allergic reactions, making it a target for understanding these. Mechanics of T cell receptors are largely unexplained by static structures available from x-ray crystallographic studies. A small number of molecular dynamic simulations have been conducted on TCR, however are currently lacking either portions of the receptor or explanations for differences between binding and non-binding TCR recognition of respective peptide-HLA. We performed molecular dynamic simulations of a TCR containing variable domain Vβ20-1, sequenced from drug responsive T cells. These were initially from a patient showing maculopapular eruptions in response to the sulfanilamide-antibiotic sulfamethoxazole (SMX). The CDR2β domain of this TCR was found to dock SMX with high affinity. Using this compound as a perturbation, overall mechanisms involved in responses mediated by this receptor were explored, showing a chemical action on the TCR free from HLA or peptide interaction. Our simulations show two completely separate modes of binding cognate peptide-HLA complexes, with an increased affinity induced by SMX bound to the Vβ20-1. Overall binding of the TCR is mediated through a primary recognition by either the variable β or α domain, and a switch in recognition within these across TCR loops contacting the peptide and HLA occurs when SMX is present in the CDR2β loop. Large binding affinity differences are induced by summed small amino acid changes primarily by SMX modifying only three critical CDR2β loop amino acid positions. These residues, TYRβ57, ASPβ64, and LYSβ65 initially hold hydrogen bonds from the CDR2β to adjacent CDR loops. Effects from SMX binding are amplified and traverse longer distances through internal TCR hydrogen bonding networks, controlling the overall TCR conformation. Thus, the CDR2β of Vβ20-1 acts as a ligand controlled switch affecting overall TCR binding affinity.
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Uchtenhagen H, Abualrous ET, Stahl E, Allerbring EB, Sluijter M, Zacharias M, Sandalova T, van Hall T, Springer S, Nygren PÅ, Achour A. Proline substitution independently enhances H-2D(b) complex stabilization and TCR recognition of melanoma-associated peptides. Eur J Immunol 2013; 43:3051-60. [PMID: 23939911 DOI: 10.1002/eji.201343456] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Revised: 07/08/2013] [Accepted: 08/08/2013] [Indexed: 11/08/2022]
Abstract
The immunogenicity of H-2D(b) (D(b)) restricted epitopes can be significantly increased by substituting peptide position 3 to a proline (p3P). The p3P modification enhances MHC stability without altering the conformation of the modified epitope allowing for T-cell cross-reactivity with the native peptide. The present study reveals how specific interactions between p3P and the highly conserved MHC heavy chain residue Y159 increase the stability of D(b) in complex with an optimized version of the melanoma-associated epitope gp10025-33 . Furthermore, the p3P modification directly increased the affinity of the D(b)/gp10025-33 -specific T-cell receptor (TCR) pMel. Surprisingly, the enhanced TCR binding was independent from the observed increased stability of the optimized D(b)/gp10025-33 complex and from the interactions formed between p3P and Y159, indicating a direct effect of the p3P modification on TCR recognition.
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Affiliation(s)
- Hannes Uchtenhagen
- Science for Life Laboratory, Center for Infectious Medicine (CIM), Department of Medicine, Karolinska Insitutet, Karolinska University Hospital Huddinge, Stockholm, Sweden
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