1
|
Ren X, Amarajeewa AWP, Jayasinghe MDT, Garstka MA. Differences in F pocket impact on HLA I genetic associations with autoimmune diabetes. Front Immunol 2024; 15:1342335. [PMID: 38596688 PMCID: PMC11003304 DOI: 10.3389/fimmu.2024.1342335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 02/26/2024] [Indexed: 04/11/2024] Open
Abstract
Introduction Human leukocyte antigen (HLA) I molecules present antigenic peptides to activate CD8+ T cells. Type 1 Diabetes (T1D) is an auto-immune disease caused by aberrant activation of the CD8+ T cells that destroy insulin-producing pancreatic β cells. Some HLA I alleles were shown to increase the risk of T1D (T1D-predisposing alleles), while some reduce this risk (T1D-protective alleles). Methods Here, we compared the T1D-predisposing and T1D-protective allotypes concerning peptide binding, maturation, localization and surface expression and correlated it with their sequences and energetic profiles using experimental and computational methods. Results T1D-predisposing allotypes had more peptide-bound forms and higher plasma membrane levels than T1D-protective allotypes. This was related to the fact that position 116 within the F pocket was more conserved and made more optimal contacts with the neighboring residues in T1D-predisposing allotypes than in protective allotypes. Conclusion Our work uncovers that specific polymorphisms in HLA I molecules potentially influence their susceptibility to T1D.
Collapse
Affiliation(s)
- Xu Ren
- Department of Urology, Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, China
- Core Research Laboratory, Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, China
- Department of Endocrinology, Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, China
| | - A. W. Peshala Amarajeewa
- Core Research Laboratory, Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, China
| | | | - Malgorzata A. Garstka
- Department of Urology, Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, China
- Core Research Laboratory, Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, China
- Department of Endocrinology, Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, China
- Department of Tumor and Immunology, Precision Medical Institute, Western China Science and Technology Innovation Port, Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, China
| |
Collapse
|
2
|
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.
Collapse
|
3
|
Lenart I, Truong LH, Nguyen DD, Rasiukienė O, Tsao E, Armstrong J, Kumar P, McHugh K, Pereira BI, Maan BS, Garstka MA, Bowness P, Blake N, Powis SJ, Gould K, Nesbeth D, Antoniou AN. Intrinsic Folding Properties of the HLA-B27 Heavy Chain Revealed by Single Chain Trimer Versions of Peptide-Loaded Class I Major Histocompatibility Complex Molecules. Front Immunol 2022; 13:902135. [PMID: 35958592 PMCID: PMC9359109 DOI: 10.3389/fimmu.2022.902135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 06/14/2022] [Indexed: 11/13/2022] Open
Abstract
Peptide-loaded Major Histocompatibility Complex (pMHC) class I molecules can be expressed in a single chain trimeric (SCT) format, composed of a specific peptide fused to the light chain beta-2 microglobulin (β2m) and MHC class I heavy chain (HC) by flexible linker peptides. pMHC SCTs have been used as effective molecular tools to investigate cellular immunity and represent a promising vaccine platform technology, due to their intracellular folding and assembly which is apparently independent of host cell folding pathways and chaperones. However, certain MHC class I HC molecules, such as the Human Leukocyte Antigen B27 (HLA-B27) allele, present a challenge due to their tendency to form HC aggregates. We constructed a series of single chain trimeric molecules to determine the behaviour of the HLA-B27 HC in a scenario that usually allows for efficient MHC class I molecule folding. When stably expressed, a pMHC SCT incorporating HLA-B27 HC formed chaperone-bound homodimers within the endoplasmic reticulum (ER). A series of HLA-B27 SCT substitution mutations revealed that the F pocket and antigen binding groove regions of the HLA-B27 HC defined the folding and dimerisation of the single chain complex, independently of the peptide sequence. Furthermore, pMHC SCTs can demonstrate variability in their association with the intracellular antigen processing machinery.
Collapse
Affiliation(s)
- Izabela Lenart
- Division of Infection and Immunity/Centre of Rheumatology, University College London, London, United Kingdom
- Centre of Rheumatology, University College London, London, United Kingdom
- Clinical Trials and Regulatory Affairs, Science Pharma, Warsaw, Poland
| | - Linh-Huyen Truong
- Department of Applied Sciences, Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom
- University of Oxford, Botnar Research Centre, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Oxford, United Kingdom
| | - Dinh Dung Nguyen
- Department of Applied Sciences, Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom
- Medical Genetics Department, Medical Genetics centre, Vinmec Research Institute of Stem Cell and Gene Technology, Hanoi, Vietnam
| | - Olga Rasiukienė
- Department of Applied Sciences, Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom
| | - Edward Tsao
- Division of Infection and Immunity/Centre of Rheumatology, University College London, London, United Kingdom
| | - Jonathan Armstrong
- School of Medicine and Biological Sciences Research Complex, University of St. Andrews, Scotland, United Kingdom
| | - Pankaj Kumar
- School of Medicine and Biological Sciences Research Complex, University of St. Andrews, Scotland, United Kingdom
| | - Kirsty McHugh
- The Nuffield Department of Orthopaedics Rheumatology and Musculoskeletal Science, Oxford University, Oxford, United Kingdom
- Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Branca I. Pereira
- Division of Infection and Immunity/Centre of Rheumatology, University College London, London, United Kingdom
- Centre of Rheumatology, University College London, London, United Kingdom
- Research and Development Department, Chelsea and Westminster Hospital National Health Service (NHS) Foundation Trust, London, United Kingdom
| | - Balraj S. Maan
- Department of Applied Sciences, Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom
- School of Medical Education, The Faculty of Medical Sciences, Newcastle University, Newcastle Upon Tyne, United Kingdom
| | - Malgorzata A. Garstka
- Core Research Laboratory, Department of Endocrinology, National & Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, Second Affiliated Hospital, School of Medicine, Xi’an Jiaotong University, Xi’an, China
| | - Paul Bowness
- The Nuffield Department of Orthopaedics Rheumatology and Musculoskeletal Science, Oxford University, Oxford, United Kingdom
| | - Neil Blake
- Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
| | - Simon J. Powis
- School of Medicine and Biological Sciences Research Complex, University of St. Andrews, Scotland, United Kingdom
| | - Keith Gould
- Wright-Fleming Institute, Imperial College London, London, United Kingdom
| | - Darren Nesbeth
- The Advanced Centre for Biochemical Engineering, University College London, London, United Kingdom
| | - Antony N. Antoniou
- Department of Applied Sciences, Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom
- The Advanced Centre for Biochemical Engineering, University College London, London, United Kingdom
- *Correspondence: Antony N. Antoniou,
| |
Collapse
|
4
|
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.
Collapse
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
| |
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
Reardon B, Koşaloğlu-Yalçın Z, Paul S, Peters B, Sette A. Allele-Specific Thresholds of Eluted Ligands for T-Cell Epitope Prediction. Mol Cell Proteomics 2021; 20:100122. [PMID: 34303001 PMCID: PMC8724920 DOI: 10.1016/j.mcpro.2021.100122] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 06/30/2021] [Accepted: 07/04/2021] [Indexed: 01/01/2023] Open
Abstract
A common strategy for predicting candidate human leukocyte antigen class I T-cell epitopes is to use an affinity-based threshold of 500 nM. Although a 500 nM threshold across alleles effectively identifies most epitopes across alleles, findings showing that major histocompatibility complex repertoire sizes vary by allele indicate that using thresholds specific to individual alleles may improve epitope identification. In this work, we compare different strategies utilizing common and allele-specific thresholds to identify an optimal approach for T-cell epitope prediction. First, we confirmed previous observations that different human leukocyte antigen class I alleles correspond with varying repertoire sizes. Here, we define general and allele-specific thresholds that capture 80% of eluted ligands and a different set of thresholds associated with capturing 9-mer T-cell epitopes at 80% sensitivity. Our analysis revealed that allele-specific threshold performance was roughly equivalent to that of a common threshold when considering a relatively large number of alleles. However, when predicting epitopes for only a few alleles, the use of allele-specific thresholds would be preferable. Finally, we present here for public use a set of allele-specific thresholds that may be used to identify T-cell epitopes at 80% sensitivity. Confirmed findings that different HLA class I alleles have varying repertoire sizes. Defined common and allele-specific thresholds that capture 80% of eluted ligands. Defined common and allele-specific thresholds that capture 80% of T-cell epitopes. Allele-specific thresholds perform more consistently when analyzing a few alleles.
Collapse
Affiliation(s)
- Brian Reardon
- Division of Vaccine Discovery, La Jolla Institute for Immunology, La Jolla, California, USA
| | | | - Sinu Paul
- Division of Vaccine Discovery, La Jolla Institute for Immunology, La Jolla, California, USA
| | - Bjoern Peters
- Division of Vaccine Discovery, La Jolla Institute for Immunology, La Jolla, California, USA; Department of Medicine, University of California, San Diego, San Diego, California, USA
| | - Alessandro Sette
- Division of Vaccine Discovery, La Jolla Institute for Immunology, La Jolla, California, USA; Department of Medicine, University of California, San Diego, San Diego, California, USA.
| |
Collapse
|
7
|
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.
Collapse
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.
| |
Collapse
|
8
|
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.
Collapse
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.
| |
Collapse
|
9
|
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.
Collapse
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.
| |
Collapse
|
10
|
Abualrous ET, Sticht J, Freund C. Major histocompatibility complex (MHC) class I and class II proteins: impact of polymorphism on antigen presentation. Curr Opin Immunol 2021; 70:95-104. [PMID: 34052735 DOI: 10.1016/j.coi.2021.04.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 04/23/2021] [Accepted: 04/25/2021] [Indexed: 01/01/2023]
Abstract
The major histocompatibility complex (MHC) loci are amongst the most polymorphic regions in the genomes of vertebrates. In the human population, thousands of MHC gene variants (alleles) exist that translate into distinct allotypes equipped with overlapping but unique peptide binding profiles. Understanding the differential structural and dynamic properties of MHC alleles and their interaction with critical regulators of peptide exchange bears the potential for more personalized strategies of immune modulation in the context of HLA-associated diseases.
Collapse
Affiliation(s)
- Esam T Abualrous
- Protein Biochemistry, Institute for Biochemistry, Freie Universität Berlin, Thielallee 63, 14195 Berlin, Germany
| | - Jana Sticht
- Protein Biochemistry, Institute for Biochemistry, Freie Universität Berlin, Thielallee 63, 14195 Berlin, Germany
| | - Christian Freund
- Protein Biochemistry, Institute for Biochemistry, Freie Universität Berlin, Thielallee 63, 14195 Berlin, Germany.
| |
Collapse
|
11
|
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.
Collapse
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.
| |
Collapse
|
12
|
Ma J, Ayres CM, Hellman LM, Devlin JR, Baker BM. Dynamic allostery controls the peptide sensitivity of the Ly49C natural killer receptor. J Biol Chem 2021; 296:100686. [PMID: 33891944 PMCID: PMC8138769 DOI: 10.1016/j.jbc.2021.100686] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 04/14/2021] [Accepted: 04/19/2021] [Indexed: 11/30/2022] Open
Abstract
Using a variety of activating and inhibitory receptors, natural killer (NK) cells protect against disease by eliminating cells that have downregulated class I major histocompatibility complex (MHC) proteins, such as in response to cell transformation or viral infection. The inhibitory murine NK receptor Ly49C specifically recognizes the class I MHC protein H-2Kb. Unusual among NK receptors, Ly49C exhibits a peptide-dependent sensitivity to H-2Kb recognition, which has not been explained despite detailed structural studies. To gain further insight into Ly49C peptide sensitivity, we examined Ly49C recognition biochemically and through the lens of dynamic allostery. We found that the peptide sensitivity of Ly49C arises through small differences in H-2Kb-binding affinity. Although molecular dynamics simulations supported a role for peptide-dependent protein dynamics in producing these differences in binding affinity, calorimetric measurements indicated an enthalpically as opposed to entropically driven process. A quantitative linkage analysis showed that this emerges from peptide-dependent dynamic tuning of electrostatic interactions across the Ly49C–H-2Kb interface. We propose a model whereby different peptides alter the flexibility of H-2Kb, which in turn changes the strength of electrostatic interactions across the protein–protein interface. Our results provide a quantitative assessment of how peptides alter Ly49C-binding affinity, suggest the underlying mechanism, and demonstrate peptide-driven allostery at work in class I MHC proteins. Lastly, our model provides a solution for how dynamic allostery could impact binding of some, but not all, class I MHC partners depending on the structural and chemical composition of the interfaces.
Collapse
Affiliation(s)
- Jiaqi Ma
- Department of Chemistry & Biochemistry and the Harper Cancer Research Institute, University of Notre Dame, Notre Dame, Indiana, USA
| | - Cory M Ayres
- Department of Chemistry & Biochemistry and the Harper Cancer Research Institute, University of Notre Dame, Notre Dame, Indiana, USA
| | - Lance M Hellman
- Department of Physical and Life Sciences, Nevada State College, Henderson, Nevada, USA
| | - Jason R Devlin
- Department of Chemistry & Biochemistry and the Harper Cancer Research Institute, University of Notre Dame, Notre Dame, Indiana, USA
| | - Brian M Baker
- Department of Chemistry & Biochemistry and the Harper Cancer Research Institute, University of Notre Dame, Notre Dame, Indiana, USA.
| |
Collapse
|
13
|
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.
Collapse
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.
| |
Collapse
|
14
|
Smith AR, Alonso JA, Ayres CM, Singh NK, Hellman LM, Baker BM. Structurally silent peptide anchor modifications allosterically modulate T cell recognition in a receptor-dependent manner. Proc Natl Acad Sci U S A 2021; 118:e2018125118. [PMID: 33468649 PMCID: PMC7848747 DOI: 10.1073/pnas.2018125118] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Presentation of peptides by class I MHC proteins underlies T cell immune responses to pathogens and cancer. The association between peptide binding affinity and immunogenicity has led to the engineering of modified peptides with improved MHC binding, with the hope that these peptides would be useful for eliciting cross-reactive immune responses directed toward their weak binding, unmodified counterparts. Increasing evidence, however, indicates that T cell receptors (TCRs) can perceive such anchor-modified peptides differently than wild-type (WT) peptides, although the scope of discrimination is unclear. We show here that even modifications at primary anchors that have no discernible structural impact can lead to substantially stronger or weaker T cell recognition depending on the TCR. Surprisingly, the effect of peptide anchor modification can be sensed by a TCR at regions distant from the site of modification, indicating a through-protein mechanism in which the anchor residue serves as an allosteric modulator for TCR binding. Our findings emphasize caution in the use and interpretation of results from anchor-modified peptides and have implications for how anchor modifications are accounted for in other circumstances, such as predicting the immunogenicity of tumor neoantigens. Our data also highlight an important need to better understand the highly tunable dynamic nature of class I MHC proteins and the impact this has on various forms of immune recognition.
Collapse
MESH Headings
- Allosteric Regulation
- Binding Sites
- Cloning, Molecular
- Crystallography, X-Ray
- Escherichia coli/genetics
- Escherichia coli/metabolism
- Gene Expression
- Genetic Vectors/chemistry
- Genetic Vectors/metabolism
- HLA-A2 Antigen/chemistry
- HLA-A2 Antigen/genetics
- HLA-A2 Antigen/immunology
- Humans
- Jurkat Cells
- Kinetics
- Models, Molecular
- Peptides/chemistry
- Peptides/genetics
- Peptides/immunology
- Protein Binding
- Protein Conformation, alpha-Helical
- Protein Conformation, beta-Strand
- Protein Engineering
- 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
- Th2 Cells/cytology
- Th2 Cells/immunology
- Thermodynamics
Collapse
Affiliation(s)
- Angela R Smith
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
- Harper Cancer Research Institute, University of Notre Dame, Notre Dame, IN 46556
| | - Jesus A Alonso
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
- Harper Cancer Research Institute, University of Notre Dame, Notre Dame, IN 46556
| | - Cory M Ayres
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
- Harper Cancer Research Institute, University of Notre Dame, Notre Dame, IN 46556
| | - Nishant K Singh
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
- Harper Cancer Research Institute, University of Notre Dame, Notre Dame, IN 46556
| | - Lance M Hellman
- Department of Physical and Life Sciences, Nevada State College, Henderson, NV 89002
| | - Brian M Baker
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556;
- Harper Cancer Research Institute, University of Notre Dame, Notre Dame, IN 46556
| |
Collapse
|
15
|
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.
Collapse
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
| |
Collapse
|
16
|
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]
|
17
|
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.
Collapse
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
| |
Collapse
|
18
|
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.
Collapse
|
19
|
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: 20] [Impact Index Per Article: 5.0] [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.
Collapse
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; ,
| |
Collapse
|
20
|
Molecular determinants of chaperone interactions on MHC-I for folding and antigen repertoire selection. Proc Natl Acad Sci U S A 2019; 116:25602-25613. [PMID: 31796585 PMCID: PMC6926029 DOI: 10.1073/pnas.1915562116] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The interplay between a highly polymorphic set of MHC-I alleles and molecular chaperones shapes the repertoire of peptide antigens displayed on the cell surface for T cell surveillance. Here, we demonstrate that the molecular chaperone TAP-binding protein related (TAPBPR) associates with a broad range of partially folded MHC-I species inside the cell. Bimolecular fluorescence complementation and deep mutational scanning reveal that TAPBPR recognition is polarized toward the α2 domain of the peptide-binding groove, and depends on the formation of a conserved MHC-I disulfide epitope in the α2 domain. Conversely, thermodynamic measurements of TAPBPR binding for a representative set of properly conformed, peptide-loaded molecules suggest a narrower MHC-I specificity range. Using solution NMR, we find that the extent of dynamics at "hotspot" surfaces confers TAPBPR recognition of a sparsely populated MHC-I state attained through a global conformational change. Consistently, restriction of MHC-I groove plasticity through the introduction of a disulfide bond between the α1/α2 helices abrogates TAPBPR binding, both in solution and on a cellular membrane, while intracellular binding is tolerant of many destabilizing MHC-I substitutions. Our data support parallel TAPBPR functions of 1) chaperoning unstable MHC-I molecules with broad allele-specificity at early stages of their folding process, and 2) editing the peptide cargo of properly conformed MHC-I molecules en route to the surface, which demonstrates a narrower specificity. Our results suggest that TAPBPR exploits localized structural adaptations, both near and distant to the peptide-binding groove, to selectively recognize discrete conformational states sampled by MHC-I alleles, toward editing the repertoire of displayed antigens.
Collapse
|
21
|
Thomas C, Tampé R. MHC I chaperone complexes shaping immunity. Curr Opin Immunol 2019; 58:9-15. [DOI: 10.1016/j.coi.2019.01.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 12/16/2018] [Accepted: 01/04/2019] [Indexed: 01/21/2023]
|
22
|
Ayres CM, Abualrous ET, Bailey A, Abraham C, Hellman LM, Corcelli SA, Noé F, Elliott T, Baker BM. Dynamically Driven Allostery in MHC Proteins: Peptide-Dependent Tuning of Class I MHC Global Flexibility. Front Immunol 2019; 10:966. [PMID: 31130956 PMCID: PMC6509175 DOI: 10.3389/fimmu.2019.00966] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Accepted: 04/15/2019] [Indexed: 11/21/2022] Open
Abstract
T cell receptor (TCR) recognition of antigenic peptides bound and presented by class I major histocompatibility complex (MHC) proteins underlies the cytotoxic immune response to diseased cells. Crystallographic structures of TCR-peptide/MHC complexes have demonstrated how TCRs simultaneously interact with both the peptide and the MHC protein. However, it is increasingly recognized that, beyond serving as a static platform for peptide presentation, the physical properties of class I MHC proteins are tuned by different peptides in ways that are not always structurally visible. These include MHC protein motions, or dynamics, which are believed to influence interactions with a variety of MHC-binding proteins, including not only TCRs, but other activating and inhibitory receptors as well as components of the peptide loading machinery. Here, we investigated the mechanisms by which peptides tune the dynamics of the common class I MHC protein HLA-A2. By examining more than 50 lengthy molecular dynamics simulations of HLA-A2 presenting different peptides, we identified regions susceptible to dynamic tuning, including regions in the peptide binding domain as well as the distal α3 domain. Further analyses of the simulations illuminated mechanisms by which the influences of different peptides are communicated throughout the protein, and involve regions of the peptide binding groove, the β2-microglobulin subunit, and the α3 domain. Overall, our results demonstrate that the class I MHC protein is a highly tunable peptide sensor whose physical properties vary considerably with bound peptide. Our data provides insight into the underlying principles and suggest a role for dynamically driven allostery in the immunological function of MHC proteins.
Collapse
Affiliation(s)
- Cory M Ayres
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States.,Harper Cancer Research Institute, University of Notre Dame, South Bend, IN, United States
| | - Esam T Abualrous
- Computational Molecular Biology Group, Institute for Mathematics, Freie Universität Berlin, Berlin, Germany
| | - Alistair Bailey
- Institute for Life Sciences and Centre for Cancer Immunology, University of Southampton, Southampton, United Kingdom
| | - Christian Abraham
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States.,Harper Cancer Research Institute, University of Notre Dame, South Bend, IN, United States
| | - Lance M Hellman
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States.,Harper Cancer Research Institute, University of Notre Dame, South Bend, IN, United States
| | - Steven A Corcelli
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States
| | - Frank Noé
- Computational Molecular Biology Group, Institute for Mathematics, Freie Universität Berlin, Berlin, Germany
| | - Tim Elliott
- Institute for Life Sciences and Centre for Cancer Immunology, University of Southampton, Southampton, United Kingdom
| | - Brian M Baker
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States.,Harper Cancer Research Institute, University of Notre Dame, South Bend, IN, United States
| |
Collapse
|
23
|
Successive crystal structure snapshots suggest the basis for MHC class I peptide loading and editing by tapasin. Proc Natl Acad Sci U S A 2019; 116:5055-5060. [PMID: 30808808 DOI: 10.1073/pnas.1807656116] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
MHC-I epitope presentation to CD8+ T cells is directly dependent on peptide loading and selection during antigen processing. However, the exact molecular bases underlying peptide selection and binding by MHC-I remain largely unknown. Within the peptide-loading complex, the peptide editor tapasin is key to the selection of MHC-I-bound peptides. Here, we have determined an ensemble of crystal structures of MHC-I in complex with the peptide exchange-associated dipeptide GL, as well as the tapasin-associated scoop loop, alone or in combination with candidate epitopes. These results combined with mutation analyses allow us to propose a molecular model underlying MHC-I peptide selection by tapasin. The N termini of bound peptides most probably bind first in the N-terminal and middle region of the MHC-I peptide binding cleft, upon which the peptide C termini are tested for their capacity to dislodge the tapasin scoop loop from the F pocket of the MHC-I cleft. Our results also indicate important differences in peptide selection between different MHC-I alleles.
Collapse
|
24
|
Montealegre S, van Endert PM. Endocytic Recycling of MHC Class I Molecules in Non-professional Antigen Presenting and Dendritic Cells. Front Immunol 2019; 9:3098. [PMID: 30666258 PMCID: PMC6330327 DOI: 10.3389/fimmu.2018.03098] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 12/13/2018] [Indexed: 12/14/2022] Open
Abstract
Major histocompatibility complex class I (MHC I) molecules are glycoproteins that display peptide epitopes at the cell surface of nucleated cells for recognition by CD8+ T cells. Like other cell surface receptors, MHC class I molecules are continuously removed from the surface followed by intracellular degradation or recycling to the cell surface, in a process likely involving active quality control the mechanism of which remains unknown. The molecular players and pathways involved in internalization and recycling have previously been studied in model cell lines such as HeLa. However, dendritic cells (DCs), which rely on a specialized endocytic machinery that confers them the unique ability to “cross”-present antigens acquired by internalization, may use distinct MHC I recycling pathways and quality control mechanisms. By providing MHC I molecules cross-presenting antigens, these pathways may play an important role in one of the key functions of DCs, priming of T cell responses against pathogens and tumors. In this review, we will focus on endocytic recycling of MHC I molecules in various experimental conditions and cell types. We discuss the organization of the recycling pathway in model cell lines compared to DCs, highlighting the differences in the recycling rates and pathways of MHC I molecules between various cell types, and their putative functional consequences. Reviewing the literature, we find that conclusive evidence for significant recycling of MHC I molecules in primary DCs has yet to be demonstrated. We conclude that endocytic trafficking of MHC class I in DCs remains poorly understood and should be further studied because of its likely role in antigen cross-presentation.
Collapse
Affiliation(s)
- Sebastian Montealegre
- Institut National de la Santé et de la Recherche Médicale, Unité 1151, Paris, France.,Université Paris Descartes, Faculté de Médecine, Paris, France.,Centre National de la Recherche Scientifique, UMR8253, Paris, France
| | - Peter M van Endert
- Institut National de la Santé et de la Recherche Médicale, Unité 1151, Paris, France.,Université Paris Descartes, Faculté de Médecine, Paris, France.,Centre National de la Recherche Scientifique, UMR8253, Paris, France
| |
Collapse
|
25
|
Ilca FT, Neerincx A, Hermann C, Marcu A, Stevanović S, Deane JE, Boyle LH. TAPBPR mediates peptide dissociation from MHC class I using a leucine lever. eLife 2018; 7:40126. [PMID: 30484775 PMCID: PMC6307860 DOI: 10.7554/elife.40126] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Accepted: 11/28/2018] [Indexed: 11/29/2022] Open
Abstract
Tapasin and TAPBPR are known to perform peptide editing on major histocompatibility complex class I (MHC I) molecules; however, the precise molecular mechanism(s) involved in this process remain largely enigmatic. Here, using immunopeptidomics in combination with novel cell-based assays that assess TAPBPR-mediated peptide exchange, we reveal a critical role for the K22-D35 loop of TAPBPR in mediating peptide exchange on MHC I. We identify a specific leucine within this loop that enables TAPBPR to facilitate peptide dissociation from MHC I. Moreover, we delineate the molecular features of the MHC I F pocket required for TAPBPR to promote peptide dissociation in a loop-dependent manner. These data reveal that chaperone-mediated peptide editing on MHC I can occur by different mechanisms dependent on the C-terminal residue that the MHC I accommodates in its F pocket and provide novel insights that may inform the therapeutic potential of TAPBPR manipulation to increase tumour immunogenicity.
Collapse
Affiliation(s)
- F Tudor Ilca
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Andreas Neerincx
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Clemens Hermann
- Department of Integrative Biomedical Sciences, Division of Chemical and Systems Biology, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - Ana Marcu
- Department of Immunology, Interfaculty Institute for Cell Biology, University of Tübingen, Tübingen, Germany
| | - Stefan Stevanović
- Department of Immunology, Interfaculty Institute for Cell Biology, University of Tübingen, Tübingen, Germany.,DKFZ Partner Site Tübingen, German Cancer Consortium, Tübingen, Germany
| | - Janet E Deane
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Louise H Boyle
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| |
Collapse
|
26
|
Kelly A, Trowsdale J. Genetics of antigen processing and presentation. Immunogenetics 2018; 71:161-170. [PMID: 30215098 PMCID: PMC6394470 DOI: 10.1007/s00251-018-1082-2] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 08/24/2018] [Indexed: 12/31/2022]
Abstract
Immune response to disease requires coordinated expression of an army of molecules. The highly polymorphic MHC class I and class II molecules are key to control of specificity of antigen presentation. Processing of the antigen, to peptides or other moieties, requires other sets of molecules. For classical class I, this includes TAP peptide transporters, proteasome components and Tapasin, genes which are encoded within the MHC. Similarly, HLA-DO and -DM, which influence presentation by HLA class II molecules, are encoded in the MHC region. Analysis of MHC mutants, including point mutations and large deletions, has been central to understanding the roles of these genes. Mouse genetics has also played a major role. Many other genes have been identified including those controlling expression of HLA class I and class II at the transcriptional level. Another genetic approach that has provided insight has been the analysis of microorganisms, including viruses and bacteria that escape immune recognition by blocking these antigen processing and presentation pathways. Here, we provide a brief history of the genetic approaches, both traditional and modern, that have been used in the quest to understand antigen processing and presentation.
Collapse
Affiliation(s)
- Adrian Kelly
- Department of Pathology, University of Cambridge, Cambridge, CB21QP, UK
| | - John Trowsdale
- Department of Pathology, University of Cambridge, Cambridge, CB21QP, UK.
| |
Collapse
|
27
|
Natarajan K, Jiang J, May NA, Mage MG, Boyd LF, McShan AC, Sgourakis NG, Bax A, Margulies DH. The Role of Molecular Flexibility in Antigen Presentation and T Cell Receptor-Mediated Signaling. Front Immunol 2018; 9:1657. [PMID: 30065727 PMCID: PMC6056622 DOI: 10.3389/fimmu.2018.01657] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 07/04/2018] [Indexed: 01/20/2023] Open
Abstract
Antigen presentation is a cellular process that involves a number of steps, beginning with the production of peptides by proteolysis or aberrant synthesis and the delivery of peptides to cellular compartments where they are loaded on MHC class I (MHC-I) or MHC class II (MHC-II) molecules. The selective loading and editing of high-affinity immunodominant antigens is orchestrated by molecular chaperones: tapasin/TAP-binding protein, related for MHC-I and HLA-DM for MHC-II. Once peptide/MHC (pMHC) complexes are assembled, following various steps of quality control, they are delivered to the cell surface, where they are available for identification by αβ receptors on CD8+ or CD4+ T lymphocytes. In addition, recognition of cell surface peptide/MHC-I complexes by natural killer cell receptors plays a regulatory role in some aspects of the innate immune response. Many of the components of the pathways of antigen processing and presentation and of T cell receptor (TCR)-mediated signaling have been studied extensively by biochemical, genetic, immunological, and structural approaches over the past several decades. Until recently, however, dynamic aspects of the interactions of peptide with MHC, MHC with molecular chaperones, or of pMHC with TCR have been difficult to address experimentally, although computational approaches such as molecular dynamics (MD) simulations have been illuminating. Studies exploiting X-ray crystallography, cryo-electron microscopy, and multidimensional nuclear magnetic resonance (NMR) spectroscopy are beginning to reveal the importance of molecular flexibility as it pertains to peptide loading onto MHC molecules, the interactions between pMHC and TCR, and subsequent TCR-mediated signals. In addition, recent structural and dynamic insights into how molecular chaperones define peptide selection and fine-tune the MHC displayed antigen repertoire are discussed. Here, we offer a review of current knowledge that highlights experimental data obtained by X-ray crystallography and multidimensional NMR methodologies. Collectively, these findings strongly support a multifaceted role for protein plasticity and conformational dynamics throughout the antigen processing and presentation pathway in dictating antigen selection and recognition.
Collapse
Affiliation(s)
- Kannan Natarajan
- Molecular Biology Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Jiansheng Jiang
- Molecular Biology Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Nathan A May
- Molecular Biology Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Michael G Mage
- Molecular Biology Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Lisa F Boyd
- Molecular Biology Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Andrew C McShan
- Department of Chemistry and Biochemistry, University of California at Santa Cruz, Santa Cruz, CA, United States
| | - Nikolaos G Sgourakis
- Department of Chemistry and Biochemistry, University of California at Santa Cruz, Santa Cruz, CA, United States
| | - Ad Bax
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - David H Margulies
- Molecular Biology Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| |
Collapse
|
28
|
Geng J, Zaitouna AJ, Raghavan M. Selected HLA-B allotypes are resistant to inhibition or deficiency of the transporter associated with antigen processing (TAP). PLoS Pathog 2018; 14:e1007171. [PMID: 29995954 PMCID: PMC6056074 DOI: 10.1371/journal.ppat.1007171] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 07/23/2018] [Accepted: 06/20/2018] [Indexed: 11/18/2022] Open
Abstract
Major histocompatibility complex class I (MHC-I) molecules present antigenic peptides to CD8+ T cells, and are also important for natural killer (NK) cell immune surveillance against infections and cancers. MHC-I molecules are assembled via a complex assembly pathway in the endoplasmic reticulum (ER) of cells. Peptides present in the cytosol of cells are transported into the ER via the transporter associated with antigen processing (TAP). In the ER, peptides are assembled with MHC-I molecules via the peptide-loading complex (PLC). Components of the MHC-I assembly pathway are frequently targeted by viruses, in order to evade host immunity. Many viruses encode inhibitors of TAP, which is thought to be a central source of peptides for the assembly of MHC-I molecules. However, human MHC-I (HLA-I) genes are highly polymorphic, and it is conceivable that several variants can acquire peptides via TAP-independent pathways, thereby conferring resistance to pathogen-derived inhibitors of TAP. To broadly assess TAP-independent expression within the HLA-B locus, expression levels of 27 frequent HLA-B alleles were tested in cells with deficiencies in TAP. Approximately 15% of tested HLA-B allotypes are expressed at relatively high levels on the surface of TAP1 or TAP2-deficient cells and occur in partially peptide-receptive forms and Endoglycosidase H sensitive forms on the cell surface. Synergy between high peptide loading efficiency, broad specificity for peptides prevalent within unconventional sources and high intrinsic stability of the empty form allows for deviations from the conventional HLA-I assembly pathway for some HLA-B*35, HLA-B*57 and HLA-B*15 alleles. Allotypes that display higher expression in TAP-deficient cells are more resistant to viral TAP inhibitor-induced HLA-I down-modulation, and HLA-I down-modulation-induced NK cell activation. Conversely, the same allotypes are expected to mediate stronger CD8+ T cell responses under TAP-inhibited conditions. Thus, the degree of resistance to TAP inhibition functionally separates specific HLA-B allotypes. Human leukocyte antigen (HLA) class I molecules present pathogen-derived components (peptides) to cytotoxic T cells, thereby inducing the T cells to kill virus-infected cells. A complex cellular pathway involving the transporter associated with antigen processing (TAP) is typically required for the loading of peptides onto HLA class I molecules, and for effective anti-viral immunity mediated by cytotoxic T cells. Many viruses encode inhibitors of TAP as a means to evade anti-viral immunity by cytotoxic T cells. In humans, there are three sets of genes encoding HLA class I molecules, which are the HLA-A, HLA-B and HLA-C genes. These genes are highly variable, with thousands of allelic variants in human populations. Most individuals typically express two variants of each gene, one inherited from each parent. We demonstrate that about 15% of tested HLA-B allotypes have higher resistance to viral inhibitors of TAP or deficiency of TAP, compared to other HLA-B variants. HLA-B allotypes that are more resistant to TAP inhibition are expected to induce stronger CD8+ T cell responses against pathogens that inhibit TAP. Thus, unconventional TAP-independent assembly pathways are broadly prevalent among HLA-B variants. Such pathways provide mechanisms to effectively combat viruses that evade the conventional TAP-dependent HLA-B assembly pathway.
Collapse
Affiliation(s)
- Jie Geng
- Department of Microbiology and Immunology, Michigan Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Anita J. Zaitouna
- Department of Microbiology and Immunology, Michigan Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Malini Raghavan
- Department of Microbiology and Immunology, Michigan Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail:
| |
Collapse
|
29
|
Jiang J, Natarajan K, Boyd LF, Morozov GI, Mage MG, Margulies DH. Crystal structure of a TAPBPR-MHC I complex reveals the mechanism of peptide editing in antigen presentation. Science 2017; 358:1064-1068. [PMID: 29025991 PMCID: PMC6320693 DOI: 10.1126/science.aao5154] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 10/04/2017] [Indexed: 12/15/2022]
Abstract
Central to CD8+ T cell-mediated immunity is the recognition of peptide-major histocompatibility complex class I (p-MHC I) proteins displayed by antigen-presenting cells. Chaperone-mediated loading of high-affinity peptides onto MHC I is a key step in the MHC I antigen presentation pathway. However, the structure of MHC I with a chaperone that facilitates peptide loading has not been determined. We report the crystal structure of MHC I in complex with the peptide editor TAPBPR (TAP-binding protein-related), a tapasin homolog. TAPBPR remodels the peptide-binding groove of MHC I, resulting in the release of low-affinity peptide. Changes include groove relaxation, modifications of key binding pockets, and domain adjustments. This structure captures a peptide-receptive state of MHC I and provides insights into the mechanism of peptide editing by TAPBPR and, by analogy, tapasin.
Collapse
Affiliation(s)
- Jiansheng Jiang
- Molecular Biology Section, Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kannan Natarajan
- Molecular Biology Section, Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Lisa F Boyd
- Molecular Biology Section, Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Giora I Morozov
- Molecular Biology Section, Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
- Hebrew University of Jerusalem, Robert H. Smith Faculty of Agriculture, Food and Environment, Rehovot 76100, Israel
| | - Michael G Mage
- Molecular Biology Section, Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - David H Margulies
- Molecular Biology Section, Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
| |
Collapse
|
30
|
Ayres CM, Corcelli SA, Baker BM. Peptide and Peptide-Dependent Motions in MHC Proteins: Immunological Implications and Biophysical Underpinnings. Front Immunol 2017; 8:935. [PMID: 28824655 PMCID: PMC5545744 DOI: 10.3389/fimmu.2017.00935] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 07/21/2017] [Indexed: 01/28/2023] Open
Abstract
Structural biology of peptides presented by class I and class II MHC proteins has transformed immunology, impacting our understanding of fundamental immune mechanisms and allowing researchers to rationalize immunogenicity and design novel vaccines. However, proteins are not static structures as often inferred from crystallographic structures. Their components move and breathe individually and collectively over a range of timescales. Peptides bound within MHC peptide-binding grooves are no exception and their motions have been shown to impact recognition by T cell and other receptors in ways that influence function. Furthermore, peptides tune the motions of MHC proteins themselves, which impacts recognition of peptide/MHC complexes by other proteins. Here, we review the motional properties of peptides in MHC binding grooves and discuss how peptide properties can influence MHC motions. We briefly review theoretical concepts about protein motion and highlight key data that illustrate immunological consequences. We focus primarily on class I systems due to greater availability of data, but segue into class II systems as the concepts and consequences overlap. We suggest that characterization of the dynamic “energy landscapes” of peptide/MHC complexes and the resulting functional consequences is one of the next frontiers in structural immunology.
Collapse
Affiliation(s)
- Cory M Ayres
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States.,Harper Cancer Research Institute, University of Notre Dame, South Bend, IN, United States
| | - Steven A Corcelli
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States
| | - Brian M Baker
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States.,Harper Cancer Research Institute, University of Notre Dame, South Bend, IN, United States
| |
Collapse
|
31
|
Abstract
Cross-presentation of internalized antigens by dendritic cells requires efficient delivery of Major Histocompatibility Complex (MHC) class I molecules to peptide-loading compartments. Strong evidence suggests that such loading can occur outside of the endoplasmic reticulum; however, the trafficking pathways and sources of class I molecules involved are poorly understood. Examination of non-professional, non-phagocytic cells has revealed a clathrin-independent, Arf6-dependent recycling pathway likely traveled by internalized optimally loaded (closed) class I molecules. Some closed and all open MHC class I molecules travel to late endosomes to be degraded but might also partly be re-loaded with peptides and recycled. Studies of viral interference revealed pathways in which class I molecules are directed to degradation in lysosomes upon ubiquitination at the surface, or upon AP-1 and HIV-nef-dependent misrouting from the Golgi network to lysosomes. While many observations made in non-professional cells remain to be re-examined in dendritic cells, available evidence suggests that both recycling and neo-synthesized class I molecules can be loaded with cross-presented peptides. Recycling molecules can be recruited to phagosomes triggered by innate signals such as TLR4 ligands, and may therefore specialize in loading with phagocytosed antigens. In contrast, AP-1-dependent accumulation at, or trafficking through, a Golgi compartment of newly synthesized molecules appears to be important for cross-presentation of soluble proteins and possibly of long peptides that are processed in the so-called vacuolar pathway. However, significant cell biological work will be required to confirm this or any other model and to integrate knowledge on MHC class I biochemistry and trafficking in models of CD8(+) T-cell priming by dendritic cells.
Collapse
Affiliation(s)
- Peter van Endert
- Institut National de la Santé et de la Recherche Médicale, Unité 1151, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France.,Centre National de la Recherche Scientifique, Unité 8253, Paris, France
| |
Collapse
|
32
|
Fisette O, Wingbermühle S, Schäfer LV. Partial Dissociation of Truncated Peptides Influences the Structural Dynamics of the MHCI Binding Groove. Front Immunol 2017; 8:408. [PMID: 28458665 PMCID: PMC5394104 DOI: 10.3389/fimmu.2017.00408] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 03/22/2017] [Indexed: 12/29/2022] Open
Abstract
Antigen processing on MHCI involves the exchange of low-affinity peptides by high-affinity, immunodominant ones. This peptide editing process is mediated by tapasin and ERAAP at the peptide C- and N-terminus, respectively. Since tapasin does not contact the peptide directly, a sensing mechanism involving conformational changes likely allows tapasin to distinguish antigen-loaded MHCI molecules from those occupied by weakly bound, non-specific peptides. To understand this mechanism at the atomic level, we performed molecular dynamics simulations of MHCI allele B*44:02 loaded with peptides truncated or modified at the C- or N-terminus. We show that the deletion of peptide anchor residues leads to reversible, partial dissociation of the peptide from MHCI on the microsecond timescale. Fluctuations in the MHCI α2-1 helix segment, bordering the binding groove and cradled by tapasin in the PLC, are influenced by the peptide C-terminus occupying the nearby F-pocket. Simulations of tapasin complexed with MHCI bound to a low-affinity peptide show that tapasin widens the MHCI binding groove near the peptide C-terminus and weakens the attractive forces between MHCI and the peptide. Our simulations thus provide a detailed, spatially resolved picture of MHCI plasticity, revealing how peptide loading status can affect key structural regions contacting tapasin.
Collapse
Affiliation(s)
- Olivier Fisette
- Center for Theoretical Chemistry, Faculty of Chemistry and Biochemistry, Ruhr-University, Bochum, Germany
| | - Sebastian Wingbermühle
- Center for Theoretical Chemistry, Faculty of Chemistry and Biochemistry, Ruhr-University, Bochum, Germany
| | - Lars V. Schäfer
- Center for Theoretical Chemistry, Faculty of Chemistry and Biochemistry, Ruhr-University, Bochum, Germany
| |
Collapse
|
33
|
Wieczorek M, Abualrous ET, Sticht J, Álvaro-Benito M, Stolzenberg S, Noé F, Freund C. Major Histocompatibility Complex (MHC) Class I and MHC Class II Proteins: Conformational Plasticity in Antigen Presentation. Front Immunol 2017. [PMID: 28367149 DOI: 10.3389/fimmu.2017.00292.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Antigen presentation by major histocompatibility complex (MHC) proteins is essential for adaptive immunity. Prior to presentation, peptides need to be generated from proteins that are either produced by the cell's own translational machinery or that are funneled into the endo-lysosomal vesicular system. The prolonged interaction between a T cell receptor and specific pMHC complexes, after an extensive search process in secondary lymphatic organs, eventually triggers T cells to proliferate and to mount a specific cellular immune response. Once processed, the peptide repertoire presented by MHC proteins largely depends on structural features of the binding groove of each particular MHC allelic variant. Additionally, two peptide editors-tapasin for class I and HLA-DM for class II-contribute to the shaping of the presented peptidome by favoring the binding of high-affinity antigens. Although there is a vast amount of biochemical and structural information, the mechanism of the catalyzed peptide exchange for MHC class I and class II proteins still remains controversial, and it is not well understood why certain MHC allelic variants are more susceptible to peptide editing than others. Recent studies predict a high impact of protein intermediate states on MHC allele-specific peptide presentation, which implies a profound influence of MHC dynamics on the phenomenon of immunodominance and the development of autoimmune diseases. Here, we review the recent literature that describe MHC class I and II dynamics from a theoretical and experimental point of view and we highlight the similarities between MHC class I and class II dynamics despite the distinct functions they fulfill in adaptive immunity.
Collapse
Affiliation(s)
- Marek Wieczorek
- Protein Biochemistry, Institute for Biochemistry, Freie Universität Berlin , Berlin , Germany
| | - Esam T Abualrous
- Computational Molecular Biology Group, Institute for Mathematics , Berlin , Germany
| | - Jana Sticht
- Protein Biochemistry, Institute for Biochemistry, Freie Universität Berlin , Berlin , Germany
| | - Miguel Álvaro-Benito
- Protein Biochemistry, Institute for Biochemistry, Freie Universität Berlin , Berlin , Germany
| | | | - Frank Noé
- Computational Molecular Biology Group, Institute for Mathematics , Berlin , Germany
| | - Christian Freund
- Protein Biochemistry, Institute for Biochemistry, Freie Universität Berlin , Berlin , Germany
| |
Collapse
|
34
|
Wieczorek M, Abualrous ET, Sticht J, Álvaro-Benito M, Stolzenberg S, Noé F, Freund C. Major Histocompatibility Complex (MHC) Class I and MHC Class II Proteins: Conformational Plasticity in Antigen Presentation. Front Immunol 2017; 8:292. [PMID: 28367149 PMCID: PMC5355494 DOI: 10.3389/fimmu.2017.00292] [Citation(s) in RCA: 543] [Impact Index Per Article: 77.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 02/28/2017] [Indexed: 11/21/2022] Open
Abstract
Antigen presentation by major histocompatibility complex (MHC) proteins is essential for adaptive immunity. Prior to presentation, peptides need to be generated from proteins that are either produced by the cell’s own translational machinery or that are funneled into the endo-lysosomal vesicular system. The prolonged interaction between a T cell receptor and specific pMHC complexes, after an extensive search process in secondary lymphatic organs, eventually triggers T cells to proliferate and to mount a specific cellular immune response. Once processed, the peptide repertoire presented by MHC proteins largely depends on structural features of the binding groove of each particular MHC allelic variant. Additionally, two peptide editors—tapasin for class I and HLA-DM for class II—contribute to the shaping of the presented peptidome by favoring the binding of high-affinity antigens. Although there is a vast amount of biochemical and structural information, the mechanism of the catalyzed peptide exchange for MHC class I and class II proteins still remains controversial, and it is not well understood why certain MHC allelic variants are more susceptible to peptide editing than others. Recent studies predict a high impact of protein intermediate states on MHC allele-specific peptide presentation, which implies a profound influence of MHC dynamics on the phenomenon of immunodominance and the development of autoimmune diseases. Here, we review the recent literature that describe MHC class I and II dynamics from a theoretical and experimental point of view and we highlight the similarities between MHC class I and class II dynamics despite the distinct functions they fulfill in adaptive immunity.
Collapse
Affiliation(s)
- Marek Wieczorek
- Protein Biochemistry, Institute for Biochemistry, Freie Universität Berlin , Berlin , Germany
| | - Esam T Abualrous
- Computational Molecular Biology Group, Institute for Mathematics , Berlin , Germany
| | - Jana Sticht
- Protein Biochemistry, Institute for Biochemistry, Freie Universität Berlin , Berlin , Germany
| | - Miguel Álvaro-Benito
- Protein Biochemistry, Institute for Biochemistry, Freie Universität Berlin , Berlin , Germany
| | | | - Frank Noé
- Computational Molecular Biology Group, Institute for Mathematics , Berlin , Germany
| | - Christian Freund
- Protein Biochemistry, Institute for Biochemistry, Freie Universität Berlin , Berlin , Germany
| |
Collapse
|
35
|
van Hateren A, Bailey A, Elliott T. Recent advances in Major Histocompatibility Complex (MHC) class I antigen presentation: Plastic MHC molecules and TAPBPR-mediated quality control. F1000Res 2017; 6:158. [PMID: 28299193 PMCID: PMC5321123 DOI: 10.12688/f1000research.10474.1] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/13/2017] [Indexed: 01/25/2023] Open
Abstract
We have known since the late 1980s that the function of classical major histocompatibility complex (MHC) class I molecules is to bind peptides and display them at the cell surface to cytotoxic T cells. Recognition by these sentinels of the immune system can lead to the destruction of the presenting cell, thus protecting the host from pathogens and cancer. Classical MHC class I molecules (MHC I hereafter) are co-dominantly expressed, polygenic, and exceptionally polymorphic and have significant sequence diversity. Thus, in most species, there are many different MHC I allotypes expressed, each with different peptide-binding specificity, which can have a dramatic effect on disease outcome. Although MHC allotypes vary in their primary sequence, they share common tertiary and quaternary structures. Here, we review the evidence that, despite this commonality, polymorphic amino acid differences between allotypes alter the ability of MHC I molecules to change shape (that is, their conformational plasticity). We discuss how the peptide loading co-factor tapasin might modify this plasticity to augment peptide loading. Lastly, we consider recent findings concerning the functions of the non-classical MHC I molecule HLA-E as well as the tapasin-related protein TAPBPR (transporter associated with antigen presentation binding protein-related), which has been shown to act as a second quality-control stage in MHC I antigen presentation.
Collapse
Affiliation(s)
- Andy van Hateren
- Institute for Life Sciences and Cancer Sciences Unit, University of Southampton, Southampton, UK
| | - Alistair Bailey
- Institute for Life Sciences and Cancer Sciences Unit, University of Southampton, Southampton, UK
| | - Tim Elliott
- Institute for Life Sciences and Cancer Sciences Unit, University of Southampton, Southampton, UK
| |
Collapse
|
36
|
Thomas C, Tampé R. Proofreading of Peptide-MHC Complexes through Dynamic Multivalent Interactions. Front Immunol 2017; 8:65. [PMID: 28228754 PMCID: PMC5296336 DOI: 10.3389/fimmu.2017.00065] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 01/16/2017] [Indexed: 11/18/2022] Open
Abstract
The adaptive immune system is able to detect and destroy cells that are malignantly transformed or infected by intracellular pathogens. Specific immune responses against these cells are elicited by antigenic peptides that are presented on major histocompatibility complex class I (MHC I) molecules and recognized by cytotoxic T lymphocytes at the cell surface. Since these MHC I-presented peptides are generated in the cytosol by proteasomal protein degradation, they can be metaphorically described as a window providing immune cells with insights into the state of the cellular proteome. A crucial element of MHC I antigen presentation is the peptide-loading complex (PLC), a multisubunit machinery, which contains as key constituents the transporter associated with antigen processing (TAP) and the MHC I-specific chaperone tapasin (Tsn). While TAP recognizes and shuttles the cytosolic antigenic peptides into the endoplasmic reticulum (ER), Tsn samples peptides in the ER for their ability to form stable complexes with MHC I, a process called peptide proofreading or peptide editing. Through its selection of peptides that improve MHC I stability, Tsn contributes to the hierarchy of immunodominant peptide epitopes. Despite the fact that it concerns a key event in adaptive immunity, insights into the catalytic mechanism of peptide proofreading carried out by Tsn have only lately been gained via biochemical, biophysical, and structural studies. Furthermore, a Tsn homolog called TAP-binding protein-related (TAPBPR) has only recently been demonstrated to function as a second MHC I-specific chaperone and peptide proofreader. Although TAPBPR is PLC-independent and has a distinct allomorph specificity, it is likely to share a common catalytic mechanism with Tsn. This review focuses on the current knowledge of the multivalent protein–protein interactions and the concomitant dynamic molecular processes underlying peptide-proofreading catalysis. We do not only derive a model that highlights the common mechanistic principles shared by the MHC I editors Tsn and TAPBPR, and the MHC II editor HLA-DM, but also illustrate the distinct quality control strategies employed by these chaperones to sample epitopes. Unraveling the mechanistic underpinnings of catalyzed peptide proofreading will be crucial for a thorough understanding of many aspects of immune recognition, from infection control and tumor immunity to autoimmune diseases and transplant rejection.
Collapse
Affiliation(s)
- Christoph Thomas
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt , Frankfurt am Main , Germany
| | - Robert Tampé
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt , Frankfurt am Main , Germany
| |
Collapse
|
37
|
Prevosto C, Usmani MF, McDonald S, Gumienny AM, Key T, Goodman RS, Gaston JSH, Deery MJ, Busch R. Allele-Independent Turnover of Human Leukocyte Antigen (HLA) Class Ia Molecules. PLoS One 2016; 11:e0161011. [PMID: 27529174 PMCID: PMC4987023 DOI: 10.1371/journal.pone.0161011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 07/28/2016] [Indexed: 11/29/2022] Open
Abstract
Major histocompatibility complex class I (MHCI) glycoproteins present cytosolic peptides to CD8+ T cells and regulate NK cell activity. Their heavy chains (HC) are expressed from up to three MHC gene loci (human leukocyte antigen [HLA]-A, -B, and -C in humans), whose extensive polymorphism maps predominantly to the antigen-binding groove, diversifying the bound peptide repertoire. Codominant expression of MHCI alleles is thus functionally critical, but how it is regulated is not fully understood. Here, we have examined the effect of polymorphism on the turnover rates of MHCI molecules in cell lines with functional MHCI peptide loading pathways and in monocyte-derived dendritic cells (MoDCs). Proteins were labeled biosynthetically with heavy water (2H2O), folded MHCI molecules immunoprecipitated, and tryptic digests analysed by mass spectrometry. MHCI-derived peptides were assigned to specific alleles and isotypes, and turnover rates quantified by 2H incorporation, after correcting for cell growth. MHCI turnover half-lives ranged from undetectable to a few hours, depending on cell type, activation state, donor, and MHCI isotype. However, in all settings, the turnover half-lives of alleles of the same isotype were similar. Thus, MHCI protein turnover rates appear to be allele-independent in normal human cells. We propose that this is an important feature enabling the normal function and codominant expression of MHCI alleles.
Collapse
Affiliation(s)
- Claudia Prevosto
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - M. Farooq Usmani
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Sarah McDonald
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | | | - Tim Key
- Tissue Typing Laboratory, Addenbrooke’s Hospital, Cambridge, United Kingdom
| | - Reyna S. Goodman
- Tissue Typing Laboratory, Addenbrooke’s Hospital, Cambridge, United Kingdom
| | - J. S. Hill Gaston
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Michael J. Deery
- Cambridge Centre for Proteomics, University of Cambridge, Cambridge, United Kingdom
| | - Robert Busch
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
- Department of Life Sciences, University of Roehampton, London, United Kingdom
| |
Collapse
|
38
|
Dynamic characterization of HLA-B*44 Alleles: A comparative molecular dynamics simulation study. Comput Biol Chem 2016; 62:12-6. [DOI: 10.1016/j.compbiolchem.2016.02.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 02/19/2016] [Accepted: 02/25/2016] [Indexed: 11/24/2022]
|
39
|
Fisette O, Wingbermühle S, Tampé R, Schäfer LV. Molecular mechanism of peptide editing in the tapasin-MHC I complex. Sci Rep 2016; 6:19085. [PMID: 26754481 PMCID: PMC4709564 DOI: 10.1038/srep19085] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Accepted: 11/30/2015] [Indexed: 11/30/2022] Open
Abstract
Immune recognition of infected or malignantly transformed cells relies on antigenic peptides exposed at the cell surface by major histocompatibility complex class I (MHC I) molecules. Selection and loading of peptides onto MHC I is orchestrated by the peptide-loading complex (PLC), a multiprotein assembly whose structure has not yet been resolved. Tapasin, a central component of the PLC, stabilises MHC I and catalyses the exchange of low-affinity against high-affinity, immunodominant peptides. Up to now, the molecular basis of this peptide editing mechanism remained elusive. Here, using all-atom molecular dynamics (MD) simulations, we unravel the atomic details of how tapasin and antigen peptides act on the MHC I binding groove. Force distribution analysis reveals an intriguing molecular tug-of-war mechanism: only high-affinity peptides can exert sufficiently large forces to close the binding groove, thus overcoming the opposite forces exerted by tapasin to open it. Tapasin therefore accelerates the release of low-affinity peptides until a high-affinity antigen binds, promoting subsequent PLC break-down. Fluctuation and entropy analyses show how tapasin chaperones MHC I by stabilising it in a peptide-receptive conformation. Our results explain previous experiments and mark a key step towards a better understanding of adaptive immunity.
Collapse
Affiliation(s)
- Olivier Fisette
- Lehrstuhl für Theoretische Chemie, Ruhr-University Bochum, 44780, Germany
| | | | - Robert Tampé
- Institute of Biochemistry, Biocenter, Goethe-University Frankfurt, 60438, Germany
| | - Lars V. Schäfer
- Lehrstuhl für Theoretische Chemie, Ruhr-University Bochum, 44780, Germany
| |
Collapse
|
40
|
van Hateren A, Bailey A, Werner JM, Elliott T. Plasticity of empty major histocompatibility complex class I molecules determines peptide-selector function. Mol Immunol 2015; 68:98-101. [PMID: 25818313 PMCID: PMC4726658 DOI: 10.1016/j.molimm.2015.03.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 03/04/2015] [Accepted: 03/09/2015] [Indexed: 11/28/2022]
Abstract
Major histocompatibility complex class I (MHC I) proteins provide protection from intracellular pathogens and cancer via each of a cell's MHC I molecules binding and presenting a peptide to cytotoxic T lymphocytes. MHC I genes are highly polymorphic and can have significant diversity, with polymorphisms predominantly localised in the peptide-binding groove where they can change peptide-binding specificity. However, polymorphic residues may also determine other functional properties, such as how dependent MHC I alleles are on the peptide-loading complex for optimal acquisition of peptide cargo. We describe how differences in the peptide-binding properties of two MHC I alleles correlates with altered conformational flexibility in the peptide-empty state. We hypothesise that plasticity is an intrinsic property encoded by the protein sequence, and that co-ordinated movements of the membrane-proximal and membrane-distal domains collectively determines how dependent MHC I are on the peptide-loading complex for efficient assembly with high affinity peptides.
Collapse
Affiliation(s)
- Andy van Hateren
- Institute for Life Sciences, Building 85, M55, University of Southampton, SO17 1BJ, UK; Cancer Sciences Unit, Faculty of Medicine, University of Southampton, SO16 6YD, UK.
| | - Alistair Bailey
- Institute for Life Sciences, Building 85, M55, University of Southampton, SO17 1BJ, UK; Cancer Sciences Unit, Faculty of Medicine, University of Southampton, SO16 6YD, UK; Centre for Biological Sciences, Faculty of Natural & Environmental Sciences, Building 85, M55, University of Southampton, SO17 1BJ, UK.
| | - Jörn M Werner
- Institute for Life Sciences, Building 85, M55, University of Southampton, SO17 1BJ, UK; Centre for Biological Sciences, Faculty of Natural & Environmental Sciences, Building 85, M55, University of Southampton, SO17 1BJ, UK.
| | - Tim Elliott
- Institute for Life Sciences, Building 85, M55, University of Southampton, SO17 1BJ, UK; Cancer Sciences Unit, Faculty of Medicine, University of Southampton, SO16 6YD, UK.
| |
Collapse
|
41
|
Hermann C, Trowsdale J, Boyle LH. TAPBPR: a new player in the MHC class I presentation pathway. ACTA ACUST UNITED AC 2015; 85:155-66. [PMID: 25720504 DOI: 10.1111/tan.12538] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
In order to provide specificity for T cell responses against pathogens and tumours, major histocompatibility complex (MHC) class I molecules present high-affinity peptides at the cell surface to T cells. A key player for peptide loading is the MHC class I-dedicated chaperone tapasin. Recently we discovered a second MHC class I-dedicated chaperone, the tapasin-related protein TAPBPR. Here, we review the major steps in the MHC class I pathway and the TAPBPR data. We discuss the potential function of TAPBPR in the MHC class I pathway and the involvement of this previously uncharacterised protein in human health and disease.
Collapse
Affiliation(s)
- C Hermann
- Department of Pathology, University of Cambridge, Cambridge CB2 1QP, UK
| | | | | |
Collapse
|
42
|
Fleischmann G, Fisette O, Thomas C, Wieneke R, Tumulka F, Schneeweiss C, Springer S, Schäfer LV, Tampé R. Mechanistic Basis for Epitope Proofreading in the Peptide-Loading Complex. THE JOURNAL OF IMMUNOLOGY 2015; 195:4503-13. [DOI: 10.4049/jimmunol.1501515] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 08/31/2015] [Indexed: 02/02/2023]
|
43
|
Abualrous ET, Saini SK, Ramnarayan VR, Ilca FT, Zacharias M, Springer S. The Carboxy Terminus of the Ligand Peptide Determines the Stability of the MHC Class I Molecule H-2Kb: A Combined Molecular Dynamics and Experimental Study. PLoS One 2015; 10:e0135421. [PMID: 26270965 PMCID: PMC4535769 DOI: 10.1371/journal.pone.0135421] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Accepted: 07/21/2015] [Indexed: 11/18/2022] Open
Abstract
Major histocompatibility complex (MHC) class I molecules (proteins) bind peptides of eight to ten amino acids to present them at the cell surface to cytotoxic T cells. The class I binding groove binds the peptide via hydrogen bonds with the peptide termini and via diverse interactions with the anchor residue side chains of the peptide. To elucidate which of these interactions is most important for the thermodynamic and kinetic stability of the peptide-bound state, we have combined molecular dynamics simulations and experimental approaches in an investigation of the conformational dynamics and binding parameters of a murine class I molecule (H-2Kb) with optimal and truncated natural peptide epitopes. We show that the F pocket region dominates the conformational and thermodynamic properties of the binding groove, and that therefore the binding of the C terminus of the peptide to the F pocket region plays a crucial role in bringing about the peptide-bound state of MHC class I.
Collapse
Affiliation(s)
- Esam Tolba Abualrous
- Department of Chemistry and Life Sciences, Jacobs University Bremen, Campus Ring 1, 28759 Bremen, Germany
- Department of Physics, Faculty of Science, Ain Shams University, Cairo, Egypt
| | - Sunil Kumar Saini
- Department of Chemistry and Life Sciences, Jacobs University Bremen, Campus Ring 1, 28759 Bremen, Germany
| | - Venkat Raman Ramnarayan
- Department of Chemistry and Life Sciences, Jacobs University Bremen, Campus Ring 1, 28759 Bremen, Germany
| | - Florin Tudor Ilca
- Department of Chemistry and Life Sciences, Jacobs University Bremen, Campus Ring 1, 28759 Bremen, Germany
| | - Martin Zacharias
- Physik-Department T38, Technische Universität München, James-Franck-Strasse 1, 85748 Garching, Germany
| | - Sebastian Springer
- Department of Chemistry and Life Sciences, Jacobs University Bremen, Campus Ring 1, 28759 Bremen, Germany
- * E-mail:
| |
Collapse
|
44
|
Fritzsche S, Abualrous ET, Borchert B, Momburg F, Springer S. Release from endoplasmic reticulum matrix proteins controls cell surface transport of MHC class I molecules. Traffic 2015; 16:591-603. [PMID: 25753898 DOI: 10.1111/tra.12279] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 01/12/2015] [Accepted: 01/30/2015] [Indexed: 02/01/2023]
Abstract
The anterograde transport of secretory proteins from the endoplasmic reticulum (ER) to the plasma membrane is a multi-step process. Secretory proteins differ greatly in their transport rates to the cell surface, but the contribution of each individual step to this difference is poorly understood. Transport rates may be determined by protein folding, chaperone association in the ER, access to ER exit sites (ERES) and retrieval from the ER-Golgi intermediate compartment or the cis-Golgi to the ER. We have used a combination of folding and trafficking assays to identify the differential step in the cell surface transport of two natural allotypes of the murine major histocompatibility complex (MHC) class I peptide receptor, H-2D(b) and H-2K(b) . We find that a novel pre-ER exit process that acts on the folded lumenal part of MHC class I molecules and that drastically limits their access to ERES accounts for the transport difference of the two allotypes. Our observations support a model in which the cell surface transport of MHC class I molecules and other type I transmembrane proteins is governed by the affinity of all their folding and maturation states to the proteins of the ER matrix.
Collapse
Affiliation(s)
- Susanne Fritzsche
- Department of Life Sciences and Chemistry, Jacobs University Bremen, Bremen, Germany
| | - Esam T Abualrous
- Department of Life Sciences and Chemistry, Jacobs University Bremen, Bremen, Germany
| | - Britta Borchert
- Department of Life Sciences and Chemistry, Jacobs University Bremen, Bremen, Germany
| | - Frank Momburg
- Department of Translational Immunology, German Cancer Research Center/NCT, Heidelberg, Germany
| | - Sebastian Springer
- Department of Life Sciences and Chemistry, Jacobs University Bremen, Bremen, Germany
| |
Collapse
|
45
|
Transport and quality control of MHC class I molecules in the early secretory pathway. Curr Opin Immunol 2015; 34:83-90. [PMID: 25771183 DOI: 10.1016/j.coi.2015.02.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Revised: 02/21/2015] [Accepted: 02/24/2015] [Indexed: 12/26/2022]
Abstract
Folding and peptide binding of major histocompatibility complex (MHC) class I molecules have been thoroughly researched, but the mechanistic connection between these biochemical events and the progress of class I through the early secretory pathway is much less well understood. This review focuses on the question how the partially assembled forms of class I (which lack high-affinity peptide and/or the light chain beta-2 microglobulin) are retained inside the cell. Such investigations offer researchers exciting chances to understand the connections between class I structure, conformational dynamics, peptide binding kinetics and thermodynamics, intracellular transport, and antigen presentation.
Collapse
|
46
|
Abualrous ET, Fritzsche S, Hein Z, Al-Balushi MS, Reinink P, Boyle LH, Wellbrock U, Antoniou AN, Springer S. F pocket flexibility influences the tapasin dependence of two differentially disease-associated MHC Class I proteins. Eur J Immunol 2015; 45:1248-57. [PMID: 25615938 DOI: 10.1002/eji.201445307] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 12/06/2014] [Accepted: 01/19/2015] [Indexed: 01/01/2023]
Abstract
The human MHC class I protein HLA-B*27:05 is statistically associated with ankylosing spondylitis, unlike HLA-B*27:09, which differs in a single amino acid in the F pocket of the peptide-binding groove. To understand how this unique amino acid difference leads to a different behavior of the proteins in the cell, we have investigated the conformational stability of both proteins using a combination of in silico and experimental approaches. Here, we show that the binding site of B*27:05 is conformationally disordered in the absence of peptide due to a charge repulsion at the bottom of the F pocket. In agreement with this, B*27:05 requires the chaperone protein tapasin to a greater extent than the conformationally stable B*27:09 in order to remain structured and to bind peptide. Taken together, our data demonstrate a method to predict tapasin dependence and physiological behavior from the sequence and crystal structure of a particular class I allotype. Also watch the Video Abstract.
Collapse
Affiliation(s)
- Esam T Abualrous
- Department of Life Science and Chemistry, Jacobs University Bremen, Bremen, Germany; Department of Physics, Faculty of Science, Ain Shams University, Cairo, Egypt
| | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Ostermeir K, Springer S, Zacharias M. Coupling between side chain interactions and binding pocket flexibility in HLA-B*44:02 molecules investigated by molecular dynamics simulations. Mol Immunol 2015; 63:312-9. [DOI: 10.1016/j.molimm.2014.07.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 07/27/2014] [Accepted: 07/29/2014] [Indexed: 02/02/2023]
|
48
|
The first step of peptide selection in antigen presentation by MHC class I molecules. Proc Natl Acad Sci U S A 2015; 112:1505-10. [PMID: 25605945 DOI: 10.1073/pnas.1416543112] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
MHC class I molecules present a variable but limited repertoire of antigenic peptides for T-cell recognition. Understanding how peptide selection is achieved requires mechanistic insights into the interactions between the MHC I and candidate peptides. We find that, at first encounter, MHC I H-2K(b) considers a wide range of peptides, including those with expanded N termini and unfitting anchor residues. Discrimination occurs in the second step, when noncanonical peptides dissociate with faster exchange rates. This second step exhibits remarkable temperature sensitivity, as illustrated by numerous noncanonical peptides presented by H-2K(b) in cells cultured at 26 °C relative to 37 °C. Crystallographic analyses of H-2K(b)-peptide complexes suggest that a conformational adaptation of H-2K(b) drives the decisive step in peptide selection. We propose that MHC class I molecules consider initially a large peptide pool, subsequently refined by a temperature-sensitive induced-fit mechanism to retain the canonical peptide repertoire.
Collapse
|
49
|
Sun Y, Liu Q. Differential structural dynamics and antigenicity of two similar influenza H5N1 virus HA-specific HLA-A*0201-restricted CLT epitopes. RSC Adv 2015. [DOI: 10.1039/c4ra08874c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The free RI-10 and KI-10 peptides showed bent rather than extended conformations as binding in the cleft of the HLA-A*0201 molecule, and KI-10–HLA-A*0201 processed a much higher flexibility than RI-10–HLA-A*0201.
Collapse
Affiliation(s)
- Yeping Sun
- CAS Key Laboratory of Pathogenic Microbiology and Immunology
- Institute of Microbiology
- Chinese Academy of Sciences
- Beijing 100101
- P. R. China
| | - Qian Liu
- Supercomputing Center
- Chinese Academy of Sciences
- Beijing 100101
- P. R. China
| |
Collapse
|
50
|
Janßen L, Ramnarayan VR, Aboelmagd M, Iliopoulou M, Hein Z, Majoul I, Fritzsche S, Halenius A, Springer S. The murine cytomegalovirus immunoevasin gp40 binds MHC class I molecules to retain them in the early secretory pathway. J Cell Sci 2015; 129:219-27. [DOI: 10.1242/jcs.175620] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 10/26/2015] [Indexed: 12/30/2022] Open
Abstract
In the presence of the murine cytomegalovirus (mCMV) gp40 (m152) protein, murine major histocompatibility complex (MHC) class I molecules do not reach the cell surface but are retained in an early compartment of the secretory pathway. We find that gp40 does not impair folding or high-affinity peptide binding of class I molecules but binds to them to retain them in the endoplasmic reticulum (ER), the ER-Golgi intermediate compartment (ERGIC), and the cis-Golgi, most likely by retrieval from the cis-Golgi to the ER. We identify a sequence in gp40 that is required for both its own retention in the early secretory pathway and for that of class I molecules.
Collapse
Affiliation(s)
- Linda Janßen
- Department of Life Sciences and Chemistry, Jacobs University Bremen, Germany
| | | | - Mohamed Aboelmagd
- Department of Life Sciences and Chemistry, Jacobs University Bremen, Germany
| | - Maria Iliopoulou
- Department of Life Sciences and Chemistry, Jacobs University Bremen, Germany
| | - Zeynep Hein
- Department of Life Sciences and Chemistry, Jacobs University Bremen, Germany
| | - Irina Majoul
- Institute of Biology, University of Lübeck, Germany
| | - Susanne Fritzsche
- Department of Life Sciences and Chemistry, Jacobs University Bremen, Germany
| | - Anne Halenius
- Institute of Virology, University of Freiburg, Germany
| | - Sebastian Springer
- Department of Life Sciences and Chemistry, Jacobs University Bremen, Germany
| |
Collapse
|