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Chen J, Shen L, Guo Q, Ma S, Zhang Y, Chen J, Qu L, Ng SS, Chen X. The downregulation of Tapasin in dendritic cell regulates CD8 + T cell autophagy to hamper hepatitis B viral clearance in the induced pluripotent stem cell-derived hepatocyte organoid. J Med Virol 2024; 96:e29546. [PMID: 38516804 DOI: 10.1002/jmv.29546] [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: 09/21/2023] [Revised: 02/09/2024] [Accepted: 03/06/2024] [Indexed: 03/23/2024]
Abstract
Tapasin, a crucial molecular chaperone involved viral antigen processing and presentation, plays an important role in antivirus immunity. However, its impact on T cell differentiation in the context of virus clearance remains unclear. In this study, we employed induced pluripotent stem cells to differentiate into hepatocyte-like cell, which were subsequently inserted to the inverted colloidal crystal scaffolds, thus establishing a hepatocyte organoid (HO). By inoculating hepatitis B virus (HBV) particles in the system, we successfully engineered a robust in vitro HBV infection model for at least 3 weeks. Furthermore, we aimed to explore the effects of lentivirus-mediated short hairpin RNA (shRNA) targeting human Tapasin on the differentiation and antiviral function of CD8+ T cells. Specifically, we transfected dendritic cells (DCs) with Tapasin-shRNA and cocultured with T cells. The results demonstrated that Tapasin-shRNA transfected DCs effectively suppressed T cell proliferation and impeded HBV-specific cytotoxic T lymphocyte responses. Our investigation also revealed the role of mTOR pathway activation in reducing autophagy activity within CD8+ T cells. Expressions of autophagy-related proteins, beclin-1, LC3II/LC3I were decreased and PI3K/AKT/mTOR activity was increased in Tapasin-shRNA group. Collectively, our findings elucidate that shRNA targeting the Tapasin gene within DCs inhibits T cell differentiation by reducing autophagy activity to hamper viral clearance in the HBV-infected HO.
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Affiliation(s)
- Jinmei Chen
- Department of Infectious Diseases, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Leer Shen
- Department of Infectious Diseases, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qingxin Guo
- Department of Infectious Diseases, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Siyuan Ma
- Department of Infectious Diseases, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yi Zhang
- Department of Infectious Diseases, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jie Chen
- Department of Infectious Diseases, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Lihong Qu
- Department of Infectious Diseases, Shanghai East Hospital, Tongji University, Shanghai, China
| | - Soon Seng Ng
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Xiaohua Chen
- Department of Infectious Diseases, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
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2
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Luo X, Qiu Y, Fitzsimonds ZR, Wang Q, Chen Q, Lei YL. Immune escape of head and neck cancer mediated by the impaired MHC-I antigen presentation pathway. Oncogene 2024; 43:388-394. [PMID: 38177410 DOI: 10.1038/s41388-023-02912-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 11/29/2023] [Accepted: 11/29/2023] [Indexed: 01/06/2024]
Abstract
Tumor immune evasion is a hallmark of Head and Neck Cancers. The advent of immune checkpoint inhibitors (ICIs) in the first-line setting has transformed the management of these tumors. Unfortunately, the response rate of Head and Neck Squamous Cell Carcinomas (HNSCC) to ICIs is below 15%, regardless of the human papillomavirus (HPV) status, which might be partially related with impaired antigen presentation machinery (APM). Mechanistically, HNSCC cells are usually defective in the expression of MHC-I associated APM, while this transcriptional pathway is critical for the activation of tumor-killing effector T-cells. To specifically illuminate the phenomenon and seek for therapeutic strategies, this review summarizes the most recently identified role of genetic and functional dysregulation of the MHC-I pathway, specifically through changes at the genetic, epigenetic, post-transcriptional, and post-translational levels, which substantially contributes to HNSCC immune escape and ICI resistance. Several treatment modalities can be potentially exploited to restore APM signaling in tumors, which improves anti-tumor immunity through the activation of interferons, vaccines or rimantadine against HPV and the inhibition of EGFR, SHP-2, PI3K and MEK. Additionally, the combinatorial use of radiotherapy or cytotoxic agents with ICIs can synergize to potentiate APM signaling. Future directions would include further dissection of MHC-I related APM signaling in HNSCC and whether reversing this inhibition in combination with ICIs would elicit a more robust immune response leading to improved response rates in HNSCC. Therapeutic approaches to restore the MHC-I antigen presentation machinery in Head and Neck Cancer. (Red color texts represent the according strategies and the outcomes).
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Affiliation(s)
- Xiaobo Luo
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Research Unit of Oral Carcinogenesis and Management & Chinese Academy of Medical Sciences, Department of Oral Medicine, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Yan Qiu
- Department of Pathology, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Zackary R Fitzsimonds
- Department of Periodontics and Oral Medicine, Department of Otolaryngology-Head and Neck Surgery, Rogel Cancer Center, the University of Michigan, Ann Arbor, MI, 48109, USA
| | - Qiuhao Wang
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Research Unit of Oral Carcinogenesis and Management & Chinese Academy of Medical Sciences, Department of Oral Medicine, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Qianming Chen
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Research Unit of Oral Carcinogenesis and Management & Chinese Academy of Medical Sciences, Department of Oral Medicine, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China.
| | - Yu Leo Lei
- Department of Periodontics and Oral Medicine, Department of Otolaryngology-Head and Neck Surgery, Rogel Cancer Center, the University of Michigan, Ann Arbor, MI, 48109, USA.
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3
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Satti R, Morley JL, Boyle LH. Get into the groove! The influence of TAPBPR on cargo selection. Curr Opin Immunol 2023; 83:102346. [PMID: 37295041 DOI: 10.1016/j.coi.2023.102346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 04/28/2023] [Accepted: 05/02/2023] [Indexed: 06/12/2023]
Abstract
Since the discovery of Transporter associated with antigen processing-binding protein-related (TAPBPR) over two decades ago, extensive studies have explored its function in the context of the major histocompatibility complex class-I (MHC-I) antigen processing and presentation pathway. As a chaperone and peptide editor, TAPBPR was recently revealed to have overlapping structural features when resolved with peptide-receptive MHC-I molecules compared with the two newly solved tapasin:MHC-I structures. Despite this, the two chaperones seem to have a unique criteria for loading high-affinity peptides on MHC-I molecules. Yet, the mechanism of action of how TAPBPR creates its distinct filter in cargo selection for peptide-receptive MHC-I molecules continues to be a subject of debate.
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Affiliation(s)
- Reem Satti
- Department of Pathology, University of Cambridge, Cambridge CB2 1QP , UK
| | - Jack L Morley
- Department of Pathology, University of Cambridge, Cambridge CB2 1QP , UK
| | - Louise H Boyle
- Department of Pathology, University of Cambridge, Cambridge CB2 1QP , UK.
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4
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Lv M, Yao T, Zhang Y, Ma S, Chen J, Tang Z, Zang G, Chen X. Exosomes loading Tapasin enhance T cell immune response by autophagy to inhibit HBV replication. J Med Virol 2023; 95:e28746. [PMID: 37185848 DOI: 10.1002/jmv.28746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 03/07/2023] [Accepted: 04/08/2023] [Indexed: 05/17/2023]
Abstract
Hepatitis B virus (HBV) specific T cell immune response plays a vital role in viral clearance. Dendritic cell derived exosomes (Dexs) can activate T cell immunity effectively. Tapasin (TPN) is involved in antigen processing and specific immune recognition. In the present study, we elucidated that Dexs loading TPN (TPN-Dexs) could enhance CD8+ T cell immune response and inhibit virus replication in HBV transgenic mice. T cell immune response and the ability of inhibiting HBV replication were measured in HBV transgenic mice immunized with TPN-Dexs. Meanwhile, CD8+ T cell autophagy and specific T cell immune responses were measured in vitro and vivo, and the mechanisms probably involved in were explored. Purified TPN-Dexs could be taken up into the cytoplasm of DCs and upregulate CD8+ T cell autophagy to enhance specific T cell immune response. In addition, TPN-Dexs could increase the expression of AKT and decrease the expression of mTOR in CD8+ T cells. Further research confirmed that TPN-Dexs could inhibit virus replication and decrease the expression of HBsAg in the liver of HBV transgenic mice. Nevertheless, those also could elicit mice hepatocytes damage. In conclusion, TPN-Dexs could enhance specific CD8+ T cell immune responses via the AKT/mTOR pathway to regulate the autophagy and exert the antiviral effect in HBV transgenic mice.
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Affiliation(s)
- Mengjiao Lv
- Department of Infectious Diseases, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ting Yao
- Department of Infectious Diseases, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yi Zhang
- Department of Infectious Diseases, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Siyuan Ma
- Department of Infectious Diseases, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jinmei Chen
- Department of Infectious Diseases, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhenghao Tang
- Department of Infectious Diseases, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Guoqing Zang
- Department of Infectious Diseases, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiaohua Chen
- Department of Infectious Diseases, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
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5
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Advancing our knowledge of antigen processing with computational modelling, structural biology, and immunology. Biochem Soc Trans 2023; 51:275-285. [PMID: 36645000 DOI: 10.1042/bst20220782] [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: 09/19/2022] [Revised: 12/09/2022] [Accepted: 01/03/2023] [Indexed: 01/17/2023]
Abstract
Antigen processing is an immunological mechanism by which intracellular peptides are transported to the cell surface while bound to Major Histocompatibility Complex molecules, where they can be surveyed by circulating CD8+ or CD4+ T-cells, potentially triggering an immunological response. The antigen processing pathway is a complex multistage filter that refines a huge pool of potential peptide ligands derived from protein degradation into a smaller ensemble for surface presentation. Each stage presents unique challenges due to the number of ligands, the polymorphic nature of MHC and other protein constituents of the pathway and the nature of the interactions between them. Predicting the ensemble of displayed peptide antigens, as well as their immunogenicity, is critical for improving T cell vaccines against pathogens and cancer. Our predictive abilities have always been hindered by an incomplete empirical understanding of the antigen processing pathway. In this review, we highlight the role of computational and structural approaches in improving our understanding of antigen processing, including structural biology, computer simulation, and machine learning techniques, with a particular focus on the MHC-I pathway.
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Wingbermühle S, Schäfer LV. Partial peptide dissociation and binding groove plasticity in two major histocompatibility complex class I alleles - differences between alleles versus force field and sampling effects. RSC Adv 2022; 12:29908-29914. [PMID: 36321080 PMCID: PMC9580618 DOI: 10.1039/d2ra05324a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 10/13/2022] [Indexed: 11/06/2022] Open
Abstract
Major histocompatibility complex class I (MHC I) reports a cell's health status by presenting antigenic peptides inside its binding groove. However, MHC I binding grooves can differ largely in their plasticity, from binding grooves that are conformationally stable by themselves to those that require a high-affinity peptide to be bound to attain conformational stability. These latter MHC I alleles are dependent on the C-terminus of the peptide that stabilizes the F-pocket region of their binding grooves. It has remained unclear to what extent a peptide-MHC I complex (pMHC I) can tolerate the (intermittent) partial dissociation of high-affinity peptides, especially of the peptide's N-terminus. Using bias exchange umbrella sampling (BEUS), a technique to achieve enhanced sampling in molecular dynamics (MD) simulations, we obtained the free-energy profiles of the N-terminal dissociation of a respective high-affinity peptide from HLA-B*35:01 and HLA-B*44:02, two alleles on opposite ends of the scale regarding binding groove plasticity. The potential of mean force (PMF) for HLA-B*35:01 was calculated for two different sets of starting structures and is compared with a PMF obtained previously with a different force field to disentangle allele differences from force field and sampling effects. For both alleles, the free-energy profiles indicate that the peptide N-terminus dissociates in a substantial fraction of the pMHC I, suggesting that their crystal structures with fully bound peptides only partially capture the dynamic conformational ensemble of pMHC I in solution, and thus in the cell. In solution, high-affinity peptides are likely to dissociate partially from two alleles of major histocompatibility complex I. Despite very similar free-energy profiles, two molecular dynamics force fields predict different underlying mechanisms.![]()
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Structural mechanism of tapasin-mediated MHC-I peptide loading in antigen presentation. Nat Commun 2022; 13:5470. [PMID: 36115831 PMCID: PMC9482634 DOI: 10.1038/s41467-022-33153-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 08/26/2022] [Indexed: 11/08/2022] Open
Abstract
AbstractLoading of MHC-I molecules with peptide by the catalytic chaperone tapasin in the peptide loading complex plays a critical role in antigen presentation and immune recognition. Mechanistic insight has been hampered by the lack of detailed structural information concerning tapasin–MHC-I. We present here crystal structures of human tapasin complexed with the MHC-I molecule HLA-B*44:05, and with each of two anti-tapasin antibodies. The tapasin-stabilized peptide-receptive state of HLA-B*44:05 is characterized by distortion of the peptide binding groove and destabilization of the β2-microglobulin interaction, leading to release of peptide. Movements of the membrane proximal Ig-like domains of tapasin, HLA-B*44:05, and β2-microglobulin accompany the transition to a peptide-receptive state. Together this ensemble of crystal structures provides insights into a distinct mechanism of tapasin-mediated peptide exchange.
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8
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Müller IK, Winter C, Thomas C, Spaapen RM, Trowitzsch S, Tampé R. Structure of an MHC I–tapasin–ERp57 editing complex defines chaperone promiscuity. Nat Commun 2022; 13:5383. [PMID: 36104323 PMCID: PMC9474470 DOI: 10.1038/s41467-022-32841-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 08/19/2022] [Indexed: 11/24/2022] Open
Abstract
Adaptive immunity depends on cell surface presentation of antigenic peptides by major histocompatibility complex class I (MHC I) molecules and on stringent ER quality control in the secretory pathway. The chaperone tapasin in conjunction with the oxidoreductase ERp57 is crucial for MHC I assembly and for shaping the epitope repertoire for high immunogenicity. However, how the tapasin–ERp57 complex engages MHC I clients has not yet been determined at atomic detail. Here, we present the 2.7-Å crystal structure of a tapasin–ERp57 heterodimer in complex with peptide-receptive MHC I. Our study unveils molecular details of client recognition by the multichaperone complex and highlights elements indispensable for peptide proofreading. The structure of this transient ER quality control complex provides the mechanistic basis for the selector function of tapasin and showcases how the numerous MHC I allomorphs are chaperoned during peptide loading and editing. Adaptive immunity depends on cellular chaperone and quality control systems that are decisive for an effective presentation of foreign antigens via MHC I molecules. Here, the authors present the structure of a key chaperone-MHC I complex.
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9
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Walker-Sperling V, Digitale JC, Viard M, Martin MP, Bashirova A, Yuki Y, Ramsuran V, Kulkarni S, Naranbhai V, Li H, Anderson SK, Yum L, Clifford R, Kibuuka H, Ake J, Thomas R, Rowland-Jones S, Rek J, Arinaitwe E, Kamya M, Rodriguez-Barraquer I, Feeney ME, Carrington M. Genetic variation that determines TAPBP expression levels associates with the course of malaria in an HLA allotype-dependent manner. Proc Natl Acad Sci U S A 2022; 119:e2205498119. [PMID: 35858344 PMCID: PMC9303992 DOI: 10.1073/pnas.2205498119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 05/27/2022] [Indexed: 11/26/2022] Open
Abstract
HLA class I (HLA-I) allotypes vary widely in their dependence on tapasin (TAPBP), an integral component of the peptide-loading complex, to present peptides on the cell surface. We identified two single-nucleotide polymorphisms that regulate TAPBP messenger RNA (mRNA) expression in Africans, rs111686073 (G/C) and rs59097151 (A/G), located in an AP-2α transcription factor binding site and a microRNA (miR)-4486 binding site, respectively. rs111686073G and rs59097151A induced significantly higher TAPBP mRNA expression relative to the alternative alleles due to higher affinity for AP-2α and abrogation of miR-4486 binding, respectively. These variants associated with lower Plasmodium falciparum parasite prevalence and lower incidence of clinical malaria specifically among individuals carrying tapasin-dependent HLA-I allotypes, presumably by augmenting peptide loading, whereas tapasin-independent allotypes associated with relative protection, regardless of imputed TAPBP mRNA expression levels. Thus, an attenuated course of malaria may occur through enhanced breadth and/or magnitude of antigen presentation, an important consideration when evaluating vaccine efficacy.
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Affiliation(s)
- Victoria Walker-Sperling
- Laboratory of Integrative Cancer Immunology, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, 20892
| | - Jean C. Digitale
- Department of Medicine, University of California San Francisco, San Francisco, California, 94158
- Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, California, 94143
| | - Mathias Viard
- Laboratory of Integrative Cancer Immunology, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, 20892
- Basic Science Program, Frederick National Laboratory for Cancer Research, National Cancer Institute, Frederick, Maryland, 21702
| | - Maureen P. Martin
- Laboratory of Integrative Cancer Immunology, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, 20892
- Basic Science Program, Frederick National Laboratory for Cancer Research, National Cancer Institute, Frederick, Maryland, 21702
| | - Arman Bashirova
- Laboratory of Integrative Cancer Immunology, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, 20892
- Basic Science Program, Frederick National Laboratory for Cancer Research, National Cancer Institute, Frederick, Maryland, 21702
| | - Yuko Yuki
- Laboratory of Integrative Cancer Immunology, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, 20892
- Basic Science Program, Frederick National Laboratory for Cancer Research, National Cancer Institute, Frederick, Maryland, 21702
| | - Veron Ramsuran
- School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa
| | - Smita Kulkarni
- Texas Biomedical Research Institute, Host Pathogen Interaction Program, San Antonio, Texas, 78227
| | - Vivek Naranbhai
- School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa
- Dana Farber Cancer Institute, Department of Medical Oncology, Boston, Massachusetts, 02215
- MGH Cancer Center, Massachusetts General Hospital, Boston, Massachusetts, 02114
- Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, 02114
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), Durban, 4041, South Africa
| | - Hongchuan Li
- Basic Science Program, Frederick National Laboratory for Cancer Research, National Cancer Institute, Frederick, Maryland, 21702
- Laboratory of Cancer Immunometabolism, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, 21702
| | - Stephen K. Anderson
- Basic Science Program, Frederick National Laboratory for Cancer Research, National Cancer Institute, Frederick, Maryland, 21702
- Laboratory of Cancer Immunometabolism, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, 21702
| | - Lauren Yum
- U.S. Military HIV Research Program,, Walter Reed Army Institute of Research, Silver Spring, Maryland, 20910
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland, 20817
| | - Robert Clifford
- U.S. Military HIV Research Program,, Walter Reed Army Institute of Research, Silver Spring, Maryland, 20910
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland, 20817
| | - Hannah Kibuuka
- Makerere University Walter Reed Project, Kampala, Uganda
| | - Julie Ake
- U.S. Military HIV Research Program,, Walter Reed Army Institute of Research, Silver Spring, Maryland, 20910
| | - Rasmi Thomas
- U.S. Military HIV Research Program,, Walter Reed Army Institute of Research, Silver Spring, Maryland, 20910
| | - Sarah Rowland-Jones
- Viral Immunology Unit, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7FZ, UK
| | - John Rek
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | | | - Moses Kamya
- Infectious Diseases Research Collaboration, Kampala, Uganda
- Department of Medicine, Makerere University, Kampala, Uganda
| | | | - Margaret E. Feeney
- Department of Medicine, University of California San Francisco, San Francisco, California, 94158
- Department of Pediatrics, University of California San Francisco, San Francisco, California, 94158
| | - Mary Carrington
- Laboratory of Integrative Cancer Immunology, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, 20892
- Basic Science Program, Frederick National Laboratory for Cancer Research, National Cancer Institute, Frederick, Maryland, 21702
- Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, 02139
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10
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Xu H, Song K, Da LT. Dynamics of peptide loading into major histocompatibility complex class I molecules chaperoned by TAPBPR. Phys Chem Chem Phys 2022; 24:12397-12409. [PMID: 35575131 DOI: 10.1039/d2cp00423b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Major histocompatibility complex class I (MHC-I) molecules display antigenic peptides on the cell surface for T cell receptor scanning, thereby activating the immune response. Peptide loading into MHC-I molecules is thus a critical step during the antigen presentation process. Chaperone TAP-binding protein related (TAPBPR) plays a critical role in promoting high-affinity peptide loading into MHC-I, by discriminating against the low-affinity ones. However, the complete peptide loading dynamics into TAPBPR-bound MHC-I is still elusive. Here, we constructed kinetic network models based on hundreds of short-time MD simulations with an aggregated simulation time of ∼21.7 μs, and revealed, at atomic level, four key intermediate states of one antigenic peptide derived from melanoma-associated MART-1/Melan-A protein during its loading process into TAPBPR-bound MHC-I. We find that the TAPBPR binding at the MHC-I pocket-F can substantially reshape the distant pocket-B via allosteric regulations, which in turn promotes the following peptide N-terminal loading. Intriguingly, the partially loaded peptide could profoundly weaken the TAPBPR-MHC stability, promoting the dissociation of the TAPBPR scoop-loop (SL) region from the pocket-F to a more solvent-exposed conformation. Structural inspections further indicate that the peptide loading could remotely affect the SL binding site through both allosteric perturbations and direct contacts. In addition, another structural motif of TAPBPR, the jack hairpin region, was also found to participate in mediating the peptide editing. Our study sheds light on the detailed molecular mechanisms underlying the peptide loading process into TAPBPR-bound MHC-I and pinpoints the key structural factors responsible for dictating the peptide-loading dynamics.
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Affiliation(s)
- Honglin Xu
- Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
| | - Kaiyuan Song
- Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
| | - Lin-Tai Da
- Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
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11
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Mintaev R, Glazkova D, Bogoslovskaya E, Shipulin G. Immunogenic epitope prediction to create a universal influenza vaccine. Heliyon 2022; 8:e09364. [PMID: 35540935 PMCID: PMC9079173 DOI: 10.1016/j.heliyon.2022.e09364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 12/30/2021] [Accepted: 04/27/2022] [Indexed: 11/26/2022] Open
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12
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Margulies DH, Taylor DK, Jiang J, Boyd LF, Ahmad J, Mage MG, Natarajan K. Chaperones and Catalysts: How Antigen Presentation Pathways Cope With Biological Necessity. Front Immunol 2022; 13:859782. [PMID: 35464465 PMCID: PMC9022212 DOI: 10.3389/fimmu.2022.859782] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 03/11/2022] [Indexed: 11/13/2022] Open
Abstract
Immune recognition by T lymphocytes and natural killer (NK) cells is in large part dependent on the identification of cell surface MHC molecules bearing peptides generated from either endogenous (MHC I) or exogenous (MHC II) dependent pathways. This review focuses on MHC I molecules that coordinately fold to bind self or foreign peptides for such surface display. Peptide loading occurs in an antigen presentation pathway that includes either the multimolecular peptide loading complex (PLC) or a single chain chaperone/catalyst, TAP binding protein, related, TAPBPR, that mimics a key component of the PLC, tapasin. Recent structural and dynamic studies of TAPBPR reveal details of its function and reflect on mechanisms common to tapasin. Regions of structural conservation among species suggest that TAPBPR and tapasin have evolved to satisfy functional complexities demanded by the enormous polymorphism of MHC I molecules. Recent studies suggest that these two chaperone/catalysts exploit structural flexibility and dynamics to stabilize MHC molecules and facilitate peptide loading.
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Affiliation(s)
- David H Margulies
- Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, Molecular Biology Section, National Institutes of Health, Bethesda, MD, United States
| | - Daniel K Taylor
- Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, Molecular Biology Section, National Institutes of Health, Bethesda, MD, United States
| | - Jiansheng Jiang
- Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, Molecular Biology Section, National Institutes of Health, Bethesda, MD, United States
| | - Lisa F Boyd
- Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, Molecular Biology Section, National Institutes of Health, Bethesda, MD, United States
| | - Javeed Ahmad
- Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, Molecular Biology Section, National Institutes of Health, Bethesda, MD, United States
| | - Michael G Mage
- Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, Molecular Biology Section, National Institutes of Health, Bethesda, MD, United States
| | - Kannan Natarajan
- Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, Molecular Biology Section, National Institutes of Health, Bethesda, MD, United States
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13
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Ballabio F, Broggini L, Paissoni C, Han X, Peqini K, Sala BM, Sun R, Sandalova T, Barbiroli A, Achour A, Pellegrino S, Ricagno S, Camilloni C. l- to d-Amino Acid Substitution in the Immunodominant LCMV-Derived Epitope gp33 Highlights the Sensitivity of the TCR Recognition Mechanism for the MHC/Peptide Structure and Dynamics. ACS OMEGA 2022; 7:9622-9635. [PMID: 35350306 PMCID: PMC8945122 DOI: 10.1021/acsomega.1c06964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 02/04/2022] [Indexed: 06/14/2023]
Abstract
Presentation of pathogen-derived epitopes by major histocompatibility complex I (MHC-I) can lead to the activation and expansion of specific CD8+ T cell clones, eventually resulting in the destruction of infected target cells. Altered peptide ligands (APLs), designed to elicit immunogenicity toward a wild-type peptide, may affect the overall stability of MHC-I/peptide (pMHC) complexes and modulate the recognition by T cell receptors (TCR). Previous works have demonstrated that proline substitution at position 3 (p3P) of different MHC-restricted epitopes, including the immunodominant LCMV-derived epitope gp33 and escape variants, may be an effective design strategy to increase epitope immunogenicity. These studies hypothesized that the p3P substitution increases peptide rigidity, facilitating TCR binding. Here, molecular dynamics simulations indicate that the p3P modification rigidifies the APLs in solution predisposing them for the MHC-I loading as well as once bound to H-2Db, predisposing them for TCR binding. Our results also indicate that peptide position 6, key for interaction of H-2Db/gp33 with the TCR P14, takes a suboptimal conformation before as well as after binding to the TCR. Analyses of H-2Db in complex with APLs, in which position 6 was subjected to an l- to d-amino acid modification, revealed small conformational changes and comparable pMHC thermal stability. However, the l- to d-modification reduced significantly the binding to P14 even in the presence of the p3P modification. Our combined data highlight the sensitivity of the TCR for the conformational dynamics of pMHC and provide further tools to dissect and modulate TCR binding and immunogenicity via APLs.
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Affiliation(s)
- Federico Ballabio
- Dipartimento
di Bioscienze, Università degli Studi
di Milano, Milano 20133, Italy
| | - Luca Broggini
- Dipartimento
di Bioscienze, Università degli Studi
di Milano, Milano 20133, Italy
- Institute
of Molecular and Translational Cardiology, IRCCS Policlinico San Donato, San Donato Milanese 20097, Italy
| | - Cristina Paissoni
- Dipartimento
di Bioscienze, Università degli Studi
di Milano, Milano 20133, Italy
| | - Xiao Han
- Science
for Life Laboratory, Department of Medicine, Karolinska Institute,
& Division of Infectious Diseases, Karolinska
University Hospital, Stockholm 14186, Sweden
| | - Kaliroi Peqini
- DISFARM,
Dipartimento di Scienze Farmaceutiche, Sezione Chimica Generale e
Organica, Università degli Studi
di Milano, Milano 20122, Italy
| | - Benedetta Maria Sala
- Science
for Life Laboratory, Department of Medicine, Karolinska Institute,
& Division of Infectious Diseases, Karolinska
University Hospital, Stockholm 14186, Sweden
| | - Renhua Sun
- Science
for Life Laboratory, Department of Medicine, Karolinska Institute,
& Division of Infectious Diseases, Karolinska
University Hospital, Stockholm 14186, Sweden
| | - Tatyana Sandalova
- Science
for Life Laboratory, Department of Medicine, Karolinska Institute,
& Division of Infectious Diseases, Karolinska
University Hospital, Stockholm 14186, Sweden
| | - Alberto Barbiroli
- Dipartimento
di Scienze per gli Alimenti, la Nutrizione e l’Ambiente, Università degli Studi di Milano, Milano 20122, Italy
| | - Adnane Achour
- Science
for Life Laboratory, Department of Medicine, Karolinska Institute,
& Division of Infectious Diseases, Karolinska
University Hospital, Stockholm 14186, Sweden
| | - Sara Pellegrino
- DISFARM,
Dipartimento di Scienze Farmaceutiche, Sezione Chimica Generale e
Organica, Università degli Studi
di Milano, Milano 20122, Italy
| | - Stefano Ricagno
- Dipartimento
di Bioscienze, Università degli Studi
di Milano, Milano 20133, Italy
- Institute
of Molecular and Translational Cardiology, IRCCS Policlinico San Donato, San Donato Milanese 20097, Italy
| | - Carlo Camilloni
- Dipartimento
di Bioscienze, Università degli Studi
di Milano, Milano 20133, Italy
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14
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Hadeler A, Saikia A, Zacharias M, Springer S. Rapid peptide exchange on MHC class I by small molecules elucidates dynamics of bound peptide. CURRENT RESEARCH IN IMMUNOLOGY 2022; 3:167-174. [PMID: 36042776 PMCID: PMC9420430 DOI: 10.1016/j.crimmu.2022.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 07/05/2022] [Accepted: 08/01/2022] [Indexed: 11/26/2022] Open
Abstract
Complexes of peptides with recombinant major histocompatibility complex class I molecules (rpMHCs) are an important tool for T cell detection, isolation, and activation in cancer immunotherapy. The rapid preparation of rpMHCs is aided by peptide exchange, for which several technologies exist. Here, we show peptide exchange with small-molecule alcohols and demonstrate that they accelerate the dissociation of pre-bound peptides, creating a novel method for rapid production of rpMHCs and increasing the understanding of the conformational flexibility of the MHC-bound peptides. Small alcohols can catalyze peptide exchange on MHC-I. C-terminal peptide binding plays an important role in ethanol mediated exchange. MHC-I ethanol peptide exchange is allotype dependent.
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15
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Ilca FT, Boyle LH. The glycosylation status of MHC class I molecules impacts their interactions with TAPBPR. Mol Immunol 2021; 139:168-176. [PMID: 34543843 PMCID: PMC8524320 DOI: 10.1016/j.molimm.2021.09.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 05/16/2021] [Accepted: 09/11/2021] [Indexed: 11/20/2022]
Abstract
Glycosylation plays a crucial role in the folding, structure, quality control and trafficking of glycoproteins. Here, we explored whether the glycosylation status of MHC class I (MHC-I) molecules impacts their affinity for the peptide editor, TAPBPR. We demonstrate that the interaction between TAPBPR and MHC-I is stronger when MHC-I lacks a glycan. Subsequently, TAPBPR can dissociate peptides, even those of high affinity, more easily from non-glycosylated MHC-I compared to their glycosylated counterparts. In addition, TAPBPR is more resistant to peptide-mediated allosteric release from non-glycosylated MHC-I compared to species with a glycan attached. Consequently, we find the glycosylation status of HLA-A*68:02, -A*02:01 and -B*27:05 influences their ability to undergo TAPBPR-mediated peptide exchange. The discovery that the glycan attached to MHC-I significantly influences the affinity of their interactions with TAPBPR has important implications, on both an experimental level and in a biological context.
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Affiliation(s)
- F Tudor Ilca
- Department of Pathology, University of Cambridge, Cambridge, CB2 1QP, UK
| | - Louise H Boyle
- Department of Pathology, University of Cambridge, Cambridge, CB2 1QP, UK.
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16
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Lan H, Abualrous ET, Sticht J, Fernandez LMA, Werk T, Weise C, Ballaschk M, Schmieder P, Loll B, Freund C. Exchange catalysis by tapasin exploits conserved and allele-specific features of MHC-I molecules. Nat Commun 2021; 12:4236. [PMID: 34244493 PMCID: PMC8271027 DOI: 10.1038/s41467-021-24401-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 06/18/2021] [Indexed: 11/29/2022] Open
Abstract
The repertoire of peptides presented by major histocompatibility complex class I (MHC-I) molecules on the cell surface is tailored by the ER-resident peptide loading complex (PLC), which contains the exchange catalyst tapasin. Tapasin stabilizes MHC-I molecules and promotes the formation of stable peptide-MHC-I (pMHC-I) complexes that serve as T cell antigens. Exchange of suboptimal by high-affinity ligands is catalyzed by tapasin, but the underlying mechanism is still elusive. Here we analyze the tapasin-induced changes in MHC-I dynamics, and find the catalyst to exploit two essential features of MHC-I. First, tapasin recognizes a conserved allosteric site underneath the α2-1-helix of MHC-I, ‘loosening’ the MHC-I F-pocket region that accomodates the C-terminus of the peptide. Second, the scoop loop11–20 of tapasin relies on residue L18 to target the MHC-I F-pocket, enabling peptide exchange. Meanwhile, tapasin residue K16 plays an accessory role in catalysis of MHC-I allotypes bearing an acidic F-pocket. Thus, our results provide an explanation for the observed allele-specificity of catalyzed peptide exchange. Tapasin is part of the peptide loading complex necessary for presenting antigenic peptides on MHC-I for the induction of adaptive immunity. Here the authors show that tapasin interacts with MHC-I in both conserved and allele-specific regions to promote antigen presentation, with tapasin L18 and K16 residues both implicated in this molecular interaction.
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Affiliation(s)
- Huan Lan
- Laboratory of Protein Biochemistry, Institute for Chemistry & Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Esam T Abualrous
- Laboratory of Protein Biochemistry, Institute for Chemistry & Biochemistry, Freie Universität Berlin, Berlin, Germany.,Artificial Intelligence for the Sciences, Department of Mathematics and Computer Science, Freie Universität Berlin, Berlin, Germany
| | - Jana Sticht
- Laboratory of Protein Biochemistry, Institute for Chemistry & Biochemistry, Freie Universität Berlin, Berlin, Germany.,Core Facility BioSupraMol, Institute for Chemistry & Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Laura Maria Arroyo Fernandez
- Laboratory of Protein Biochemistry, Institute for Chemistry & Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Tamina Werk
- Laboratory of Protein Biochemistry, Institute for Chemistry & Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Christoph Weise
- Laboratory of Protein Biochemistry, Institute for Chemistry & Biochemistry, Freie Universität Berlin, Berlin, Germany.,Core Facility BioSupraMol, Institute for Chemistry & Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Martin Ballaschk
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany
| | - Peter Schmieder
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany
| | - Bernhard Loll
- Laboratory of Structural Biology, Institute for Chemistry & Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Christian Freund
- Laboratory of Protein Biochemistry, Institute for Chemistry & Biochemistry, Freie Universität Berlin, Berlin, Germany.
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17
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Truong HV, Sgourakis NG. Dynamics of MHC-I molecules in the antigen processing and presentation pathway. Curr Opin Immunol 2021; 70:122-128. [PMID: 34153556 PMCID: PMC8622473 DOI: 10.1016/j.coi.2021.04.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 04/20/2021] [Accepted: 04/30/2021] [Indexed: 01/07/2023]
Abstract
The endogenous antigen processing and presentation (APP) is a fundamental pathway found in jawed vertebrates, which allows for a set of epitope peptides sampled from the intracellular proteome to be assembled and displayed on class I proteins of the major histocompatibility complex (MHC-I). Peptide/MHC-I antigens enable different aspects of adaptive immunity to emerge, by providing a basis for recognition of self vs. non-self by T cells and Natural Killer (NK) cells. Pioneering studies of pMHC-I molecules and their higher-order protein complexes with molecular chaperones and membrane receptors have gleaned important insights into the peptide loading and antigen recognition mechanisms. While X-ray and cryoEM structures have provided us with static snapshots of different MHC-I assembly stages, complementary biophysical techniques have revealed that MHC-I molecules are highly mobile on a range of biologically relevant timescales, which bears importance for their assembly, peptide repertoire selection, membrane display and turnover. This review summarizes insights gained from experimental and simulation studies aimed at investigating MHC-I dynamics, and their functional implications.
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Affiliation(s)
- Hau V Truong
- Center for Computational and Genomic Medicine, Department of Pathology and Laboratory Medicine, The Children's Hospital of Philadelphia, 3401 Civic Center Blvd., Philadelphia, PA 19104, USA; Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, 3401 Civic Center Blvd., Philadelphia, PA 19104, USA
| | - Nikolaos G Sgourakis
- Center for Computational and Genomic Medicine, Department of Pathology and Laboratory Medicine, The Children's Hospital of Philadelphia, 3401 Civic Center Blvd., Philadelphia, PA 19104, USA; Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, 3401 Civic Center Blvd., Philadelphia, PA 19104, USA.
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18
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Hafstrand I, Aflalo A, Boyle LH. Why TAPBPR? Implications of an additional player in MHC class I peptide presentation. Curr Opin Immunol 2021; 70:90-94. [PMID: 34052734 DOI: 10.1016/j.coi.2021.04.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 04/15/2021] [Accepted: 04/30/2021] [Indexed: 10/21/2022]
Abstract
The peptide editor TAPBPR is the newest member of the major histocompatibility complex class I (MHC-I) antigen processing and presentation pathway. Since 2013, studies have explored the functions and mechanisms of action of this tapasin homolog. Here, we review the key insights gained from structural studies of the TAPBPR:MHC-I complex and the involvement of the TAPBPR loop in peptide exchange. However, despite recent advances, the question still remains: why do we need TAPBPR? The recent appreciation that different MHC-I allotypes vary in their ability to interact with TAPBPR, together with a role for TAPBPR in alternative presentation pathways highlights that much remains unknown concerning the biological need for TAPBPR.
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Affiliation(s)
- Ida Hafstrand
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, United Kingdom; Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, United Kingdom
| | - Aure Aflalo
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, United Kingdom
| | - Louise H Boyle
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, United Kingdom.
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19
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McShan AC, Devlin CA, Morozov GI, Overall SA, Moschidi D, Akella N, Procko E, Sgourakis NG. TAPBPR promotes antigen loading on MHC-I molecules using a peptide trap. Nat Commun 2021; 12:3174. [PMID: 34039964 PMCID: PMC8154891 DOI: 10.1038/s41467-021-23225-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Accepted: 04/16/2021] [Indexed: 11/08/2022] Open
Abstract
Chaperones Tapasin and TAP-binding protein related (TAPBPR) perform the important functions of stabilizing nascent MHC-I molecules (chaperoning) and selecting high-affinity peptides in the MHC-I groove (editing). While X-ray and cryo-EM snapshots of MHC-I in complex with TAPBPR and Tapasin, respectively, have provided important insights into the peptide-deficient MHC-I groove structure, the molecular mechanism through which these chaperones influence the selection of specific amino acid sequences remains incompletely characterized. Based on structural and functional data, a loop sequence of variable lengths has been proposed to stabilize empty MHC-I molecules through direct interactions with the floor of the groove. Using deep mutagenesis on two complementary expression systems, we find that important residues for the Tapasin/TAPBPR chaperoning activity are located on a large scaffolding surface, excluding the loop. Conversely, loop mutations influence TAPBPR interactions with properly conformed MHC-I molecules, relevant for peptide editing. Detailed biophysical characterization by solution NMR, ITC and FP-based assays shows that the loop hovers above the MHC-I groove to promote the capture of incoming peptides. Our results suggest that the longer loop of TAPBPR lowers the affinity requirements for peptide selection to facilitate peptide loading under conditions and subcellular compartments of reduced ligand concentration, and to prevent disassembly of high-affinity peptide-MHC-I complexes that are transiently interrogated by TAPBPR during editing.
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Affiliation(s)
- Andrew C McShan
- Center for Computational and Genomic Medicine, Department of Pathology and Laboratory Medicine, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Christine A Devlin
- Department of Biochemistry and Cancer Center at Illinois, University of Illinois, Urbana, IL, USA
| | - Giora I Morozov
- Center for Computational and Genomic Medicine, Department of Pathology and Laboratory Medicine, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Sarah A Overall
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Danai Moschidi
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Neha Akella
- Department of Biochemistry and Cancer Center at Illinois, University of Illinois, Urbana, IL, USA
| | - Erik Procko
- Department of Biochemistry and Cancer Center at Illinois, University of Illinois, Urbana, IL, USA.
| | - Nikolaos G Sgourakis
- Center for Computational and Genomic Medicine, Department of Pathology and Laboratory Medicine, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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20
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Jantz-Naeem N, Springer S. Venus flytrap or pas de trois? The dynamics of MHC class I molecules. Curr Opin Immunol 2021; 70:82-89. [PMID: 33993034 DOI: 10.1016/j.coi.2021.04.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 04/05/2021] [Accepted: 04/08/2021] [Indexed: 11/25/2022]
Abstract
The peptide binding site of major histocompatibility complex (MHC) class I molecules is natively unfolded when devoid of peptides. Peptide binding stabilizes the structure and slows the dynamics, but peptide-specific and subtype-specific motions influence, and are influenced by, interaction with assembly chaperones, the T cell receptor, and other class I-binding proteins. The molecular mechanisms of cooperation between peptide, class I heavy chain, and beta-2 microglobulin are insufficiently known but are being elucidated by nuclear magnetic resonance and other modern methods. It appears that micropolymorphic clusters of charged amino acids, often hidden in the molecule interior, determine the dynamics and thus chaperone dependence, cellular fate, and disease association of class I.
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Affiliation(s)
- Nouria Jantz-Naeem
- Department of Life Sciences and Chemistry, Jacobs University, Bremen, Germany
| | - Sebastian Springer
- Department of Life Sciences and Chemistry, Jacobs University, Bremen, Germany.
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21
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Dhatchinamoorthy K, Colbert JD, Rock KL. Cancer Immune Evasion Through Loss of MHC Class I Antigen Presentation. Front Immunol 2021; 12:636568. [PMID: 33767702 PMCID: PMC7986854 DOI: 10.3389/fimmu.2021.636568] [Citation(s) in RCA: 372] [Impact Index Per Article: 124.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 02/05/2021] [Indexed: 02/03/2023] Open
Abstract
Major histocompatibility class I (MHC I) molecules bind peptides derived from a cell's expressed genes and then transport and display this antigenic information on the cell surface. This allows CD8 T cells to identify pathological cells that are synthesizing abnormal proteins, such as cancers that are expressing mutated proteins. In order for many cancers to arise and progress, they need to evolve mechanisms to avoid elimination by CD8 T cells. MHC I molecules are not essential for cell survival and therefore one mechanism by which cancers can evade immune control is by losing MHC I antigen presentation machinery (APM). Not only will this impair the ability of natural immune responses to control cancers, but also frustrate immunotherapies that work by re-invigorating anti-tumor CD8 T cells, such as checkpoint blockade. Here we review the evidence that loss of MHC I antigen presentation is a frequent occurrence in many cancers. We discuss new insights into some common underlying mechanisms through which some cancers inactivate the MHC I pathway and consider some possible strategies to overcome this limitation in ways that could restore immune control of tumors and improve immunotherapy.
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22
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Thomas C, Tampé R. MHC I assembly and peptide editing - chaperones, clients, and molecular plasticity in immunity. Curr Opin Immunol 2021; 70:48-56. [PMID: 33689959 DOI: 10.1016/j.coi.2021.02.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Accepted: 02/07/2021] [Indexed: 11/24/2022]
Abstract
Peptides presented on MHC I molecules allow the immune system to detect diseased cells. The displayed peptides typically stem from proteasomal degradation of cytoplasmic proteins and are translocated into the ER lumen where they are trimmed and loaded onto MHC I. Peptide translocation is carried out by the transporter associated with antigen processing, which forms the central building block of a dynamic assembly called the peptide-loading complex (PLC). By coordinating peptide transfer with MHC I loading and peptide optimization, the PLC is a linchpin in the adaptive immune system. Peptide loading and optimization is catalyzed by the PLC component tapasin and the PLC-independent TAPBPR, two MHC I-dedicated enzymes chaperoning empty or suboptimally loaded MHC I and selecting stable peptide-MHC I complexes in a process called peptide editing or proofreading. Recent structural and functional studies of peptide editing have dramatically improved our understanding of this pivotal event in antigen processing/presentation. This review is dedicated to Vincenzo Cerundolo (1959-2020) for his pioneering work in the field of antigen processing/presentation.
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Affiliation(s)
- Christoph Thomas
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue Str. 9, Frankfurt, 60438 Main, Germany.
| | - Robert Tampé
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue Str. 9, Frankfurt, 60438 Main, Germany.
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23
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Bashirova AA, Viard M, Naranbhai V, Grifoni A, Garcia-Beltran W, Akdag M, Yuki Y, Gao X, O'hUigin C, Raghavan M, Wolinsky S, Bream JH, Duggal P, Martinson J, Michael NL, Kirk GD, Buchbinder SP, Haas D, Goedert JJ, Deeks SG, Fellay J, Walker B, Goulder P, Cresswell P, Elliott T, Sette A, Carlson J, Carrington M. HLA tapasin independence: broader peptide repertoire and HIV control. Proc Natl Acad Sci U S A 2020; 117:28232-28238. [PMID: 33097667 PMCID: PMC7668082 DOI: 10.1073/pnas.2013554117] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Human leukocyte antigen (HLA) class I allotypes vary in their ability to present peptides in the absence of tapasin, an essential component of the peptide loading complex. We quantified tapasin dependence of all allotypes that are common in European and African Americans (n = 97), which revealed a broad continuum of values. Ex vivo examination of cytotoxic T cell responses to the entire HIV-1 proteome from infected subjects indicates that tapasin-dependent allotypes present a more limited set of distinct peptides than do tapasin-independent allotypes, data supported by computational predictions. This suggests that variation in tapasin dependence may impact the strength of the immune responses by altering peptide repertoire size. In support of this model, we observed that individuals carrying HLA class I genotypes characterized by greater tapasin independence progress more slowly to AIDS and maintain lower viral loads, presumably due to increased breadth of peptide presentation. Thus, tapasin dependence level, like HLA zygosity, may serve as a means to restrict or expand breadth of the HLA-I peptide repertoire across humans, ultimately influencing immune responses to pathogens and vaccines.
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Affiliation(s)
- Arman A Bashirova
- Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21702
| | - Mathias Viard
- Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21702
| | - Vivek Naranbhai
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215
| | - Alba Grifoni
- Division of Vaccine Discovery, La Jolla Institute for Immunology, La Jolla, CA 92037
| | - Wilfredo Garcia-Beltran
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02139
| | - Marjan Akdag
- Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21702
| | - Yuko Yuki
- Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21702
| | - Xiaojiang Gao
- Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21702
| | - Colm O'hUigin
- Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21702
| | - Malini Raghavan
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109
| | - Steven Wolinsky
- Division of Infectious Diseases, The Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Jay H Bream
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205
| | - Priya Duggal
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205
| | - Jeremy Martinson
- Department of Infectious Diseases and Microbiology, University of Pittsburgh Graduate School of Public Health, Pittsburgh, PA 15261
| | - Nelson L Michael
- US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD 20910
| | - Gregory D Kirk
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205
| | - Susan P Buchbinder
- HIV Research Section, San Francisco Department of Public Health, San Francisco, CA 94102
| | - David Haas
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37204
| | - James J Goedert
- Infections and Immunoepidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD 20850
| | - Steven G Deeks
- Department of Medicine, University of California, San Francisco, CA 94110
| | - Jacques Fellay
- School of Life Sciences, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
- Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
| | - Bruce Walker
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02139
| | - Philip Goulder
- Department of Paediatrics, University of Oxford, Oxford, OX1 4AJ, United Kingdom
| | - Peter Cresswell
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06520
| | - Tim Elliott
- Institute for Life Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom
- Centre for Cancer Immunology, University of Southampton, Southampton SO16 6YD, United Kingdom
| | - Alessandro Sette
- Division of Vaccine Discovery, La Jolla Institute for Immunology, La Jolla, CA 92037
- Department of Medicine, University of California San Diego, La Jolla, CA 92093
| | | | - Mary Carrington
- Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21702;
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02139
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24
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Fisette O, Schröder GF, Schäfer LV. Atomistic structure and dynamics of the human MHC-I peptide-loading complex. Proc Natl Acad Sci U S A 2020; 117:20597-20606. [PMID: 32788370 PMCID: PMC7456110 DOI: 10.1073/pnas.2004445117] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The major histocompatibility complex class-I (MHC-I) peptide-loading complex (PLC) is a cornerstone of the human adaptive immune system, being responsible for processing antigens that allow killer T cells to distinguish between healthy and compromised cells. Based on a recent low-resolution cryo-electron microscopy (cryo-EM) structure of this large membrane-bound protein complex, we report an atomistic model of the PLC and study its conformational dynamics on the multimicrosecond time scale using all-atom molecular dynamics (MD) simulations in an explicit lipid bilayer and water environment (1.6 million atoms in total). The PLC has a layered structure, with two editing modules forming a flexible protein belt surrounding a stable, catalytically active core. Tapasin plays a central role in the PLC, stabilizing the MHC-I binding groove in a conformation reminiscent of antigen-loaded MHC-I. The MHC-I-linked glycan steers a tapasin loop involved in peptide editing toward the binding groove. Tapasin conformational dynamics are also affected by calreticulin through a conformational selection mechanism that facilitates MHC-I recruitment into the complex.
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Affiliation(s)
- Olivier Fisette
- Theoretical Chemistry, Ruhr University Bochum, D-44780 Bochum, Germany
| | - Gunnar F Schröder
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, D-52425 Jülich, Germany
- Jülich Centre for Structural Biology (JuStruct), Forschungszentrum Jülich, D-52425 Jülich, Germany
- Physics Department, Heinrich-Heine-Universität Düsseldorf, D-40225 Düsseldorf, Germany
| | - Lars V Schäfer
- Theoretical Chemistry, Ruhr University Bochum, D-44780 Bochum, Germany;
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25
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Ilca T, Boyle LH. The Ins and Outs of TAPBPR. Curr Opin Immunol 2020; 64:146-151. [PMID: 32814254 DOI: 10.1016/j.coi.2020.06.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 06/25/2020] [Indexed: 11/26/2022]
Abstract
Peptide presentation on MHC class I molecules (MHC-I) is central to mounting effective antiviral and antitumoral immune responses. The tapasin-related protein TAPBPR is an MHC-I peptide editor which shapes the final peptide repertoire displayed on the cell surface. Here, we review recent findings which further elucidate the mechanisms by which TAPBPR performs peptide editing on a molecular level, and how glycosylation on MHC-I influences the interaction with TAPBPR and the peptide loading complex. We also explore how the function of TAPBPR can be utilized to promote exogenous peptide loading directly onto plasma-membrane expressed MHC-I. This has led to the development of new assays to investigate TAPBPR-mediated peptide editing and uncovered translational opportunities of utilizing TAPBPR to treat human disease.
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Affiliation(s)
- Tudor Ilca
- Department of Pathology, University of Cambridge, UK
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26
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Margulies DH, Jiang J, Natarajan K. Structural and dynamic studies of TAPBPR and Tapasin reveal the mechanism of peptide loading of MHC-I molecules. Curr Opin Immunol 2020; 64:71-79. [DOI: 10.1016/j.coi.2020.04.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 03/24/2020] [Accepted: 04/03/2020] [Indexed: 12/17/2022]
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27
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Serçinoğlu O, Ozbek P. Sequence-structure-function relationships in class I MHC: A local frustration perspective. PLoS One 2020; 15:e0232849. [PMID: 32421728 PMCID: PMC7233585 DOI: 10.1371/journal.pone.0232849] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 04/22/2020] [Indexed: 12/22/2022] Open
Abstract
Class I Major Histocompatibility Complex (MHC) binds short antigenic peptides with the help of Peptide Loading Complex (PLC), and presents them to T-cell Receptors (TCRs) of cytotoxic T-cells and Killer-cell Immunglobulin-like Receptors (KIRs) of Natural Killer (NK) cells. With more than 10000 alleles, human MHC (Human Leukocyte Antigen, HLA) is the most polymorphic protein in humans. This allelic diversity provides a wide coverage of peptide sequence space, yet does not affect the three-dimensional structure of the complex. Moreover, TCRs mostly interact with HLA in a common diagonal binding mode, and KIR-HLA interaction is allele-dependent. With the aim of establishing a framework for understanding the relationships between polymorphism (sequence), structure (conserved fold) and function (protein interactions) of the human MHC, we performed here a local frustration analysis on pMHC homology models covering 1436 HLA I alleles. An analysis of local frustration profiles indicated that (1) variations in MHC fold are unlikely due to minimally-frustrated and relatively conserved residues within the HLA peptide-binding groove, (2) high frustration patches on HLA helices are either involved in or near interaction sites of MHC with the TCR, KIR, or tapasin of the PLC, and (3) peptide ligands mainly stabilize the F-pocket of HLA binding groove.
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Affiliation(s)
- Onur Serçinoğlu
- Department of Bioengineering, Recep Tayyip Erdogan University, Faculty of Engineering, Fener, Rize, Turkey
| | - Pemra Ozbek
- Department of Bioengineering, Marmara University, Faculty of Engineering, Goztepe, Istanbul, Turkey
- * E-mail:
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28
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Sagert L, Hennig F, Thomas C, Tampé R. A loop structure allows TAPBPR to exert its dual function as MHC I chaperone and peptide editor. eLife 2020; 9:55326. [PMID: 32167472 PMCID: PMC7117912 DOI: 10.7554/elife.55326] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 03/12/2020] [Indexed: 01/18/2023] Open
Abstract
Adaptive immunity vitally depends on major histocompatibility complex class I (MHC I) molecules loaded with peptides. Selective loading of peptides onto MHC I, referred to as peptide editing, is catalyzed by tapasin and the tapasin-related TAPBPR. An important catalytic role has been ascribed to a structural feature in TAPBPR called the scoop loop, but the exact function of the scoop loop remains elusive. Here, using a reconstituted system of defined peptide-exchange components including human TAPBPR variants, we uncover a substantial contribution of the scoop loop to the stability of the MHC I-chaperone complex and to peptide editing. We reveal that the scoop loop of TAPBPR functions as an internal peptide surrogate in peptide-depleted environments stabilizing empty MHC I and impeding peptide rebinding. The scoop loop thereby acts as an additional selectivity filter in shaping the repertoire of presented peptide epitopes and the formation of a hierarchical immune response.
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Affiliation(s)
- Lina Sagert
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Frankfurt, Germany
| | - Felix Hennig
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Frankfurt, Germany
| | - Christoph Thomas
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Frankfurt, Germany
| | - Robert Tampé
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Frankfurt, Germany
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29
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Structures of peptide-free and partially loaded MHC class I molecules reveal mechanisms of peptide selection. Nat Commun 2020; 11:1314. [PMID: 32161266 PMCID: PMC7066147 DOI: 10.1038/s41467-020-14862-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 02/06/2020] [Indexed: 02/08/2023] Open
Abstract
Major Histocompatibility Complex (MHC) class I molecules selectively bind peptides for presentation to cytotoxic T cells. The peptide-free state of these molecules is not well understood. Here, we characterize a disulfide-stabilized version of the human class I molecule HLA-A*02:01 that is stable in the absence of peptide and can readily exchange cognate peptides. We present X-ray crystal structures of the peptide-free state of HLA-A*02:01, together with structures that have dipeptides bound in the A and F pockets. These structural snapshots reveal that the amino acid side chains lining the binding pockets switch in a coordinated fashion between a peptide-free unlocked state and a peptide-bound locked state. Molecular dynamics simulations suggest that the opening and closing of the F pocket affects peptide ligand conformations in adjacent binding pockets. We propose that peptide binding is co-determined by synergy between the binding pockets of the MHC molecule. Major Histocompatibility Complex (MHC) class I molecules present tightly binding peptides on the cell surface for recognition by cytotoxic T cells. Here, the authors present the crystal structures of a disulfide-stabilized human MHC class I molecule in the peptide-free state and bound with dipeptides, and find that peptide binding is accompanied by concerted conformational switches of the amino acid side chains in the binding pockets.
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30
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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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31
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Trowitzsch S, Tampé R. Multifunctional Chaperone and Quality Control Complexes in Adaptive Immunity. Annu Rev Biophys 2020; 49:135-161. [PMID: 32004089 DOI: 10.1146/annurev-biophys-121219-081643] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The fundamental process of adaptive immunity relies on the differentiation of self from nonself. Nucleated cells are continuously monitored by effector cells of the immune system, which police the peptide status presented via cell surface molecules. Recent integrative structural approaches have provided insights toward our understanding of how sophisticated cellular machineries shape such hierarchical immune surveillance. Biophysical and structural achievements were invaluable for defining the interconnection of many key factors during antigen processing and presentation, and helped to solve several conundrums that persisted for many years. In this review, we illuminate the numerous quality control machineries involved in different steps during the maturation of major histocompatibility complex class I (MHC I) proteins, from their synthesis in the endoplasmic reticulum to folding and trafficking via the secretory pathway, optimization of antigenic cargo, final release to the cell surface, and engagement with their cognate receptors on cytotoxic T lymphocytes.
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Affiliation(s)
- Simon Trowitzsch
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany; ,
| | - Robert Tampé
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany; ,
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32
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Croft NP. Peptide Presentation to T Cells: Solving the Immunogenic Puzzle: Systems Immunology Profiling of Antigen Presentation for Prediction of CD8 + T Cell Immunogenicity. Bioessays 2020; 42:e1900200. [PMID: 31958157 DOI: 10.1002/bies.201900200] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 12/18/2019] [Indexed: 02/02/2023]
Abstract
The vertebrate immune system uses an impressive arsenal of mechanisms to combat harmful cellular states such as infection. One way is via cells delivering real-time snapshots of their protein content to the cell surface in the form of short peptides. Specialized immune cells (T cells) sample these peptides and assess whether they are foreign, warranting an action such as destruction of the infected cell. The delivery of peptides to the cell surface is termed antigen processing and presentation, and decades of research have provided unprecedented understanding of this process. However, predicting the capacity for a given peptide to be immunogenic-to elicit a T cell response-has remained both enigmatic and a long sought-after goal. In the era of big data, a point is being approached where the steps of antigen processing and presentation can be quantified and assessed against peptide immunogenicity in order to build predictive models. This review presents new findings in this area and contemplates challenges ahead.
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Affiliation(s)
- Nathan P Croft
- Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, 3800, Australia
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33
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Driller R, Ballaschk M, Schmieder P, Uchanska-Ziegler B, Ziegler A, Loll B. Metal-triggered conformational reorientation of a self-peptide bound to a disease-associated HLA-B*27 subtype. J Biol Chem 2019; 294:13269-13279. [PMID: 31296658 DOI: 10.1074/jbc.ra119.008937] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 07/08/2019] [Indexed: 01/03/2023] Open
Abstract
Conformational changes of major histocompatibility complex (MHC) antigens have the potential to be recognized by T cells and may arise from polymorphic variation of the MHC molecule, the binding of modifying ligands, or both. Here, we investigated whether metal ions could affect allele-dependent structural variation of the two minimally distinct human leukocyte antigen (HLA)-B*27:05 and HLA-B*27:09 subtypes, which exhibit differential association with the rheumatic disease ankylosing spondylitis (AS). We employed NMR spectroscopy and X-ray crystallography coupled with ensemble refinement to study the AS-associated HLA-B*27:05 subtype and the AS-nonassociated HLA-B* 27:09 in complex with the self-peptide pVIPR (RRKWRRWHL). Both techniques revealed that pVIPR exhibits a higher degree of flexibility when complexed with HLA-B*27:05 than with HLA-B*27:09. Furthermore, we found that the binding of the metal ion Cu2+ or Ni2+, but not Mn2+, Zn2+, or Hg2+, affects the structure of a pVIPR-bound HLA-B*27 molecule in a subtype-dependent manner. In HLA-B*27:05, the metals triggered conformational reorientations of pVIPR, but no such structural changes were observed in the HLA-B*27:09 subtype, with or without bound metal ion. These observations provide the first demonstration that not only major histocompatibility complex class II, but also class I, molecules can undergo metal ion-induced conformational alterations. Our findings suggest that metals may have a role in triggering rheumatic diseases such as AS and also have implications for the molecular basis of metal-induced hypersensitivities and allergies.
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Affiliation(s)
- Ronja Driller
- Institut für Chemie/Biochemie, AG Strukturbiochemie, Freie Universität Berlin, Takustrasse 6, 14195 Berlin, Germany
| | - Martin Ballaschk
- Leibniz-Institut für Molekulare Pharmakologie, Robert-Rössle-Strasse 10, 13125 Berlin, Germany
| | - Peter Schmieder
- Leibniz-Institut für Molekulare Pharmakologie, Robert-Rössle-Strasse 10, 13125 Berlin, Germany
| | - Barbara Uchanska-Ziegler
- Institut für Immungenetik, Charité-Universitätsmedizin Berlin, Freie Universität Berlin, Thielallee 73, 14195 Berlin, Germany; Ziegler Biosolutions, Fahrgasse 5, 79761 Waldshut-Tiengen, Germany
| | - Andreas Ziegler
- Ziegler Biosolutions, Fahrgasse 5, 79761 Waldshut-Tiengen, Germany.
| | - Bernhard Loll
- Institut für Chemie/Biochemie, AG Strukturbiochemie, Freie Universität Berlin, Takustrasse 6, 14195 Berlin, Germany; MoloX GmbH, Takustrasse 6, 14195 Berlin, Germany.
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34
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Natarajan K, Jiang J, Margulies DH. Structural aspects of chaperone-mediated peptide loading in the MHC-I antigen presentation pathway. Crit Rev Biochem Mol Biol 2019; 54:164-173. [PMID: 31084439 DOI: 10.1080/10409238.2019.1610352] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Recognition of foreign and dysregulated antigens by the cellular innate and adaptive immune systems is in large part dependent on the cell surface display of peptide/MHC (pMHC) complexes. The formation of such complexes requires the generation of antigenic peptides, proper folding of MHC molecules, loading of peptides onto MHC molecules, glycosylation, and transport to the plasma membrane. This complex series of biosynthetic, biochemical, and cell biological reactions is known as "antigen processing and presentation". Here, we summarize recent work, focused on the structural and functional characterization of the key MHC-I-dedicated chaperones, tapasin, and TAPBPR. The mechanisms reflect the ability of conformationally flexible molecules to adapt to their ligands, and are comparable to similar processes that are exploited in peptide antigen loading in the MHC-II pathway.
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Affiliation(s)
- Kannan Natarajan
- a Molecular Biology Section, Laboratory of Immune System Biology , National Institute of Allergy and Infectious Diseases, National Institutes of Health , Bethesda , MD , USA
| | - Jiansheng Jiang
- a Molecular Biology Section, Laboratory of Immune System Biology , National Institute of Allergy and Infectious Diseases, National Institutes of Health , Bethesda , MD , USA
| | - David H Margulies
- a Molecular Biology Section, Laboratory of Immune System Biology , National Institute of Allergy and Infectious Diseases, National Institutes of Health , Bethesda , MD , USA
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35
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Abstract
Major histocompatibility class I (MHC-I) molecules bind peptides derived from cellular synthesis and display them at the cell surface for recognition by receptors on T lymphocytes (TCR) or natural killer (NK) cells. Such recognition provides a crucial step in autoimmunity, identification of bacterial and viral pathogens, and anti-tumor responses. Understanding the mechanism by which such antigenic peptides in the ER are loaded and exchanged for higher affinity peptides onto MHC molecules has recently been clarified by cryo-EM and X-ray studies of the multimolecular peptide loading complex (PLC) and a unimolecular tapasin-like chaperone designated TAPBPR. Insights from these structural studies and complementary solution NMR experiments provide a basis for understanding mechanisms related to immune antigen presentation.
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