1
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Rathakrishnan P, McShan AC. In silico identification and characterization of small molecule binding to the CD1d immunoreceptor. J Biomol Struct Dyn 2023:1-19. [PMID: 38109194 DOI: 10.1080/07391102.2023.2294388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 12/04/2023] [Indexed: 12/19/2023]
Abstract
CD1 immunoreceptors are a non-classical major histocompatibility complex (MHC) that present antigens to T cells to elucidate immune responses against disease. The antigen repertoire of CD1 has been composed primarily of lipids until recently when CD1d-restricted T cells were shown to be activated by non-lipidic small molecules, such as phenyl pentamethyl dihydrobenzofuran sulfonate (PPBF) and related benzofuran sulfonates. To date structural insights into PPBF/CD1d interactions are lacking, so it is unknown whether small molecule and lipid antigens are presented and recognized through similar mechanisms. Furthermore, it is unknown whether CD1d can bind to and present a broader range of small molecule metabolites to T cells, acting out functions analogous to the MHC class I related protein MR1. Here, we perform in silico docking and molecular dynamics simulations to structurally characterize small molecule interactions with CD1d. PPBF was supported to be presented to T cell receptors through the CD1d F' pocket. Virtual screening of CD1d against more than 17,000 small molecules with diverse geometry and chemistry identified several novel scaffolds, including phytosterols, cholesterols, triterpenes, and carbazole alkaloids, that serve as candidate CD1d antigens. Protein-ligand interaction profiling revealed conserved residues in the CD1d F' pocket that similarly anchor small molecules and lipids. Our results suggest that CD1d could have the intrinsic ability to bind and present a broad range of small molecule metabolites to T cells to carry out its function beyond lipid antigen presentation.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
| | - Andrew C McShan
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, USA
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2
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Van Rhijn I. Do antigen-presenting CD1a, CD1b, CD1c, and CD1d molecules bind different self-lipids? Trends Immunol 2023; 44:757-759. [PMID: 37730500 DOI: 10.1016/j.it.2023.08.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 08/30/2023] [Indexed: 09/22/2023]
Abstract
Humans express four different lipid antigen-presenting molecules, CD1a, CD1b, CD1c, and CD1d, that are differentially expressed on antigen-presenting cells and which recycle through different endosomal compartments. Huang et al. now answer the question on whether the four CD1 isoforms selectively bind certain lipids.
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Affiliation(s)
- Ildiko Van Rhijn
- Department of Medical Biology, Amsterdam University Medical Center, Amsterdam, The Netherlands; Department of Infectious Diseases and Immunology, School of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
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3
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Farquhar R, Van Rhijn I, Moody DB, Rossjohn J, Shahine A. αβ T-cell receptor recognition of self-phosphatidylinositol presented by CD1b. J Biol Chem 2023; 299:102849. [PMID: 36587766 PMCID: PMC9900620 DOI: 10.1016/j.jbc.2022.102849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 12/21/2022] [Accepted: 12/23/2022] [Indexed: 12/31/2022] Open
Abstract
CD1 glycoproteins present lipid-based antigens to T-cell receptors (TCRs). A role for CD1b in T-cell-mediated autoreactivity was proposed when it was established that CD1b can present self-phospholipids with short alkyl chains (∼C34) to T cells; however, the structural characteristics of this presentation and recognition are unclear. Here, we report the 1.9 Å resolution binary crystal structure of CD1b presenting a self-phosphatidylinositol-C34:1 and an endogenous scaffold lipid. Moreover, we also determined the 2.4 Å structure of CD1b-phosphatidylinositol complexed to an autoreactive αβ TCR, BC8B. We show that the TCR docks above CD1b and directly contacts the presented antigen, selecting for both the phosphoinositol headgroup and glycerol neck region via antigen remodeling within CD1b and allowing lateral escape of the inositol moiety through a channel formed by the TCR α-chain. Furthermore, through alanine scanning mutagenesis and surface plasmon resonance, we identified key CD1b residues mediating this interaction, with Glu-80 abolishing TCR binding. We in addition define a role for both CD1b α1 and CD1b α2 molecular domains in modulating this interaction. These findings suggest that the BC8B TCR contacts both the presented phospholipid and the endogenous scaffold lipid via a dual mechanism of corecognition. Taken together, these data expand our understanding into the molecular mechanisms of CD1b-mediated T-cell autoreactivity.
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Affiliation(s)
- Rachel Farquhar
- Infection and Immunity Program and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Ildiko Van Rhijn
- Division of Rheumatology, Inflammation, and Immunity, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA; Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands
| | - D Branch Moody
- Division of Rheumatology, Inflammation, and Immunity, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Jamie Rossjohn
- Infection and Immunity Program and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia; Institute of Infection and Immunity, Cardiff University, School of Medicine, Cardiff, United Kingdom.
| | - Adam Shahine
- Infection and Immunity Program and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia.
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4
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Novel Molecular Insights into Human Lipid-Mediated T Cell Immunity. Int J Mol Sci 2021; 22:ijms22052617. [PMID: 33807663 PMCID: PMC7961386 DOI: 10.3390/ijms22052617] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 03/02/2021] [Accepted: 03/03/2021] [Indexed: 12/17/2022] Open
Abstract
T cells represent a critical arm of our immune defense against pathogens. Over the past two decades, considerable inroads have been made in understanding the fundamental principles underpinning the molecular presentation of peptide-based antigens by the Major Histocompatibility Complex molecules (MHC-I and II), and their molecular recognition by specialized subsets of T cells. However, some T cells can recognize lipid-based antigens presented by MHC-I-like molecules that belong to the Cluster of Differentiation 1 (CD1) family. Here, we will review the advances that have been made in the last five years to understand the molecular mechanisms orchestrating the presentation of novel endogenous and exogenous lipid-based antigens by the CD1 glycoproteins and their recognition by specific populations of CD1-reactive T cells.
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5
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Ween MP, White JB, Tran HB, Mukaro V, Jones C, Macowan M, Hodge G, Trim PJ, Snel MF, Hodge SJ. The role of oxidised self-lipids and alveolar macrophage CD1b expression in COPD. Sci Rep 2021; 11:4106. [PMID: 33602992 PMCID: PMC7892841 DOI: 10.1038/s41598-021-82481-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 12/28/2020] [Indexed: 02/08/2023] Open
Abstract
In chronic obstructive pulmonary disease (COPD) apoptotic bronchial epithelial cells are increased, and their phagocytosis by alveolar macrophages (AM) is decreased alongside bacterial phagocytosis. Epithelial cellular lipids, including those exposed on uncleared apoptotic bodies, can become oxidized, and may be recognized and presented as non-self by antigen presenting cells. CD1b is a lipid-presenting protein, previously only described in dendritic cells. We investigated whether CD1b is upregulated in COPD AM, and whether lipid oxidation products are found in the airways of cigarette smoke (CS) exposed mice. We also characterise CD1b for the first time in a range of macrophages and assess CD1b expression and phagocytic function in response to oxidised lipid. Bronchoalveolar lavage and exhaled breath condensate were collected from never-smoker, current-smoker, and COPD patients and AM CD1b expression and airway 8-isoprostane levels assessed. Malondialdehyde was measured in CS-exposed mouse airways by confocal/immunofluorescence. Oxidation of lipids produced from CS-exposed 16HBE14o- (HBE) bronchial epithelial cells was assessed by spectrophotometry and changes in lipid classes assessed by mass spectrometry. 16HBE cell toxicity was measured by flow cytometry as was phagocytosis, CD1b expression, HLA class I/II, and mannose receptor (MR) in monocyte derived macrophages (MDM). AM CD1b was significantly increased in COPD smokers (4.5 fold), COPD ex-smokers (4.3 fold), and smokers (3.9 fold), and AM CD1b significantly correlated with disease severity (FEV1) and smoking pack years. Airway 8-isoprostane also increased in smokers and COPD smokers and ex-smokers. Malondialdehyde was significantly increased in the bronchial epithelium of CS-exposed mice (MFI of 18.18 vs 23.50 for control). Oxidised lipid was produced from CS-exposed bronchial epithelial cells (9.8-fold of control) and showed a different overall lipid makeup to that of control total cellular lipid. This oxidised epithelial lipid significantly upregulated MDM CD1b, caused bronchial epithelial cell toxicity, and reduced MDM phagocytic capacity and MR in a dose dependent manner. Increased levels of oxidised lipids in the airways of COPD patients may be responsible for reduced phagocytosis and may become a self-antigen to be presented by CD1b on macrophages to perpetuate disease progression despite smoking cessation.
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Affiliation(s)
- Miranda P Ween
- Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, Australia. .,School of Medicine, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia.
| | - Jake B White
- School of Medicine, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia.,Proteomics, Metabolomics and MS Imaging Core Facility, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, Australia.,Vascular Research Centre, Lifelong Health Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, Australia
| | - Hai B Tran
- Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, Australia.,School of Medicine, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia
| | - Violet Mukaro
- Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, Australia.,Department of Critical Care, Melbourne Medical School, University of Melbourne, Melbourne, Australia
| | - Charles Jones
- School of Medicine, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia
| | - Matthew Macowan
- Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, Australia.,School of Medicine, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia
| | - Gregory Hodge
- Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, Australia.,School of Medicine, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia
| | - Paul J Trim
- School of Medicine, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia.,Proteomics, Metabolomics and MS Imaging Core Facility, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, Australia
| | - Marten F Snel
- School of Medicine, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia.,Proteomics, Metabolomics and MS Imaging Core Facility, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, Australia
| | - Sandra J Hodge
- School of Medicine, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia
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6
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Wilson IA, Stanfield RL. 50 Years of structural immunology. J Biol Chem 2021; 296:100745. [PMID: 33957119 PMCID: PMC8163984 DOI: 10.1016/j.jbc.2021.100745] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 03/24/2021] [Accepted: 04/30/2021] [Indexed: 12/12/2022] Open
Abstract
Fifty years ago, the first landmark structures of antibodies heralded the dawn of structural immunology. Momentum then started to build toward understanding how antibodies could recognize the vast universe of potential antigens and how antibody-combining sites could be tailored to engage antigens with high specificity and affinity through recombination of germline genes (V, D, J) and somatic mutation. Equivalent groundbreaking structures in the cellular immune system appeared some 15 to 20 years later and illustrated how processed protein antigens in the form of peptides are presented by MHC molecules to T cell receptors. Structures of antigen receptors in the innate immune system then explained their inherent specificity for particular microbial antigens including lipids, carbohydrates, nucleic acids, small molecules, and specific proteins. These two sides of the immune system act immediately (innate) to particular microbial antigens or evolve (adaptive) to attain high specificity and affinity to a much wider range of antigens. We also include examples of other key receptors in the immune system (cytokine receptors) that regulate immunity and inflammation. Furthermore, these antigen receptors use a limited set of protein folds to accomplish their various immunological roles. The other main players are the antigens themselves. We focus on surface glycoproteins in enveloped viruses including SARS-CoV-2 that enable entry and egress into host cells and are targets for the antibody response. This review covers what we have learned over the past half century about the structural basis of the immune response to microbial pathogens and how that information can be utilized to design vaccines and therapeutics.
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MESH Headings
- Adaptive Immunity
- Allergy and Immunology/history
- Animals
- Antibodies, Viral/chemistry
- Antibodies, Viral/genetics
- Antibodies, Viral/immunology
- Antibody Specificity
- Antigen Presentation
- Antigens, Viral/chemistry
- Antigens, Viral/genetics
- Antigens, Viral/immunology
- COVID-19/immunology
- COVID-19/virology
- Crystallography/history
- Crystallography/methods
- History, 20th Century
- History, 21st Century
- Humans
- Immunity, Innate
- Protein Folding
- Protein Interaction Domains and Motifs
- Receptors, Antigen, T-Cell/chemistry
- Receptors, Antigen, T-Cell/genetics
- Receptors, Antigen, T-Cell/immunology
- Receptors, Cytokine/chemistry
- Receptors, Cytokine/genetics
- Receptors, Cytokine/immunology
- SARS-CoV-2/immunology
- SARS-CoV-2/pathogenicity
- V(D)J Recombination
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Affiliation(s)
- Ian A Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California, USA; The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California, USA.
| | - Robyn L Stanfield
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California, USA
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7
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Camacho F, Moreno E, Garcia-Alles LF, Chinea Santiago G, Gilleron M, Vasquez A, Choong YS, Reyes F, Norazmi MN, Sarmiento ME, Acosta A. A Direct Role for the CD1b Endogenous Spacer in the Recognition of a Mycobacterium tuberculosis Antigen by T-Cell Receptors. Front Immunol 2020; 11:566710. [PMID: 33162982 PMCID: PMC7591678 DOI: 10.3389/fimmu.2020.566710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 09/10/2020] [Indexed: 11/13/2022] Open
Abstract
Lipids, glycolipids and lipopeptides derived from Mycobacterium tuberculosis (Mtb) are presented to T cells by monomorphic molecules known as CD1. This is the case of the Mtb-specific sulfoglycolipid Ac2SGL, which is presented by CD1b molecules and is recognized by T cells found in tuberculosis (TB) patients and in individuals with latent infections. Our group, using filamentous phage display technology, obtained two specific ligands against the CD1b-Ac2SGL complex: (i) a single chain T cell receptor (scTCR) from a human T cell clone recognizing the CD1b-AcSGL complex; and (ii) a light chain domain antibody (dAbκ11). Both ligands showed lower reactivity to a synthetic analog of Ac2SGL (SGL12), having a shorter acyl chain as compared to the natural antigen. Here we put forward the hypothesis that the CD1b endogenous spacer lipid (EnSpacer) plays an important role in the recognition of the CD1b-Ac2SGL complex by specific T cells. To support this hypothesis we combined: (a) molecular binding assays for both the scTCR and the dAbκ11 antibody domain against a small panel of synthetic Ac2SGL analogs having different acyl chains, (b) molecular modeling of the CD1b-Ac2SGL/EnSpacer complex, and (c) modeling of the interactions of this complex with the scTCR. Our results contribute to understand the mechanisms of lipid presentation by CD1b molecules and their interactions with T-cell receptors and other specific ligands, which may help to develop specific tools targeting Mtb infected cells for therapeutic and diagnostic applications.
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Affiliation(s)
- Frank Camacho
- Biologicals Sciences School, University of Concepcion, Concepcion, Chile
| | - Ernesto Moreno
- Faculty of Basic Sciences, University of Medellin, Medellin, Colombia
| | | | | | - Martine Gilleron
- Institut de Pharmacologie et Biologie Structurale, Université de Toulouse, Toulouse, France
| | - Aleikar Vasquez
- Biologicals Sciences School, University of Concepcion, Concepcion, Chile
| | - Yee Siew Choong
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Minden, Malaysia
| | - Fátima Reyes
- Biologicals Sciences School, University of Concepcion, Concepcion, Chile
| | - Mohd Nor Norazmi
- School of Health Sciences, Health Campus, Universiti Sains Malaysia, Kubang Kerian, Malaysia
| | - Maria E. Sarmiento
- School of Health Sciences, Health Campus, Universiti Sains Malaysia, Kubang Kerian, Malaysia
| | - Armando Acosta
- School of Health Sciences, Health Campus, Universiti Sains Malaysia, Kubang Kerian, Malaysia
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8
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Ogg G, Cerundolo V, McMichael AJ. Capturing the antigen landscape: HLA-E, CD1 and MR1. Curr Opin Immunol 2019; 59:121-129. [PMID: 31445404 DOI: 10.1016/j.coi.2019.07.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 04/12/2019] [Accepted: 07/18/2019] [Indexed: 12/15/2022]
Abstract
T cell receptor (TCR) recognition of antigens presented by relatively non-polymorphic MHC-like molecules is emerging as a significant contributor to health and disease. These evolutionarily ancient pathways have been inappropriately labelled 'non-conventional' because their roles were discovered after viral-specific peptide presentation by polymorphic MHC class I molecules. We suggest that these pathways are complementary to mainstream peptide presentation. HLA-E, CD1 and MR1 can present diverse self and foreign antigens to TCRs and therefore contribute to tissue homeostasis, pathogen defence, inflammation and immune responses to cancer. Despite presenting different classes of antigens, they share many features and are under common selective pressures. Through understanding their roles in disease, therapeutic manipulation for disease prevention and treatment should become possible.
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Affiliation(s)
- Graham Ogg
- MRC Human Immunology Unit, and Oxford NIHR Biomedical Research Centre, University of Oxford, UK
| | | | - Andrew J McMichael
- Nuffield Department of Medicine Research Building, University of Oxford, UK.
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9
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Jiang J, Natarajan K, Margulies DH. MHC Molecules, T cell Receptors, Natural Killer Cell Receptors, and Viral Immunoevasins-Key Elements of Adaptive and Innate Immunity. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1172:21-62. [PMID: 31628650 DOI: 10.1007/978-981-13-9367-9_2] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Molecules encoded by the Major Histocompatibility Complex (MHC) bind self or foreign peptides and display these at the cell surface for recognition by receptors on T lymphocytes (designated T cell receptors-TCR) or on natural killer (NK) cells. These ligand/receptor interactions govern T cell and NK cell development as well as activation of T memory and effector cells. Such cells participate in immunological processes that regulate immunity to various pathogens, resistance and susceptibility to cancer, and autoimmunity. The past few decades have witnessed the accumulation of a huge knowledge base of the molecular structures of MHC molecules bound to numerous peptides, of TCRs with specificity for many different peptide/MHC (pMHC) complexes, of NK cell receptors (NKR), of MHC-like viral immunoevasins, and of pMHC/TCR and pMHC/NKR complexes. This chapter reviews the structural principles that govern peptide/MHC (pMHC), pMHC/TCR, and pMHC/NKR interactions, for both MHC class I (MHC-I) and MHC class II (MHC-II) molecules. In addition, we discuss the structures of several representative MHC-like molecules. These include host molecules that have distinct biological functions, as well as virus-encoded molecules that contribute to the evasion of the immune response.
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Affiliation(s)
- Jiansheng Jiang
- Molecular Biology Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bldg. 10, Room 11D07, 10 Center Drive, Bethesda, MD, 20892-1892, USA.
| | - Kannan Natarajan
- Molecular Biology Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bldg. 10, Room 11D07, 10 Center Drive, Bethesda, MD, 20892-1892, USA
| | - David H Margulies
- Molecular Biology Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bldg. 10, Room 11D12, 10 Center Drive, Bethesda, MD, 20892-1892, USA
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10
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Shahine A. The intricacies of self-lipid antigen presentation by CD1b. Mol Immunol 2018; 104:27-36. [PMID: 30399491 DOI: 10.1016/j.molimm.2018.09.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 08/31/2018] [Accepted: 09/29/2018] [Indexed: 01/13/2023]
Abstract
The CD1 family of glycoproteins are MHC class I-like molecules that present a wide array of self and foreign lipid antigens to T-cell receptors (TCRs) on T-cells. Humans express three classes of CD1 molecules, denoted as Group 1 (CD1a, CD1b, and CD1c), Group 2 (CD1d), and Group 3 (CD1e). Of the CD1 family of molecules, CD1b exhibits the largest and most complex antigen binding groove; allowing it the capabilities to present a broad spectrum of lipid antigens. While its role in foreign-lipid presentation in the context of mycobacterial infection are well characterized, understanding the roles of CD1b in autoreactivity are recently being elucidated. While the mechanisms governing proliferation of CD1b-restricted autoreactive T cells, regulation of CD1 gene expression, and the processes controlling CD1+ antigen presenting cell maturation are widely undercharacterized, the exploration of self-lipid antigens in the context of disease have recently come into focus. Furthermore, the recently expanded pool of CD1b crystal structures allow the opportunity to further analyze the molecular mechanisms of T-cell recognition and self-lipid presentation; where the intricacies of the two-compartment system, that accommodate both the presented self-lipid antigen and scaffold lipids, are scrutinized. This review delves into the immunological and molecular mechanisms governing presentation and T-cell recognition of the broad self-lipid repertoire of CD1b; with evidence mounting pointing towards a role in diseases such as microbial infection, autoimmune diseases, and cancer.
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Affiliation(s)
- Adam Shahine
- Infection and Immunity Program and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia; ARC Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton Victoria 3800, Australia.
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11
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DeWitt WS, Yu KKQ, Wilburn DB, Sherwood A, Vignali M, Day CL, Scriba TJ, Robins HS, Swanson WJ, Emerson RO, Bradley PH, Seshadri C. A Diverse Lipid Antigen-Specific TCR Repertoire Is Clonally Expanded during Active Tuberculosis. THE JOURNAL OF IMMUNOLOGY 2018; 201:888-896. [PMID: 29914888 DOI: 10.4049/jimmunol.1800186] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 05/21/2018] [Indexed: 01/06/2023]
Abstract
Human T cells that recognize lipid Ags presented by highly conserved CD1 proteins often express semi-invariant TCRs, but the true diversity of lipid Ag-specific TCRs remains unknown. We use CD1b tetramers and high-throughput immunosequencing to analyze thousands of TCRs from ex vivo-sorted or in vitro-expanded T cells specific for the mycobacterial lipid Ag, glucose monomycolate. Our results reveal a surprisingly diverse repertoire resulting from editing of germline-encoded gene rearrangements analogous to MHC-restricted TCRs. We used a distance-based metric (TCRDist) to show how this diverse TCR repertoire builds upon previously reported conserved motifs by including subject-specific TCRs. In a South African cohort, we show that TCRDist can identify clonal expansion of diverse glucose monomycolate-specific TCRs and accurately distinguish patients with active tuberculosis from control subjects. These data suggest that similar mechanisms govern the selection and expansion of peptide and lipid Ag-specific T cells despite the nonpolymorphic nature of CD1.
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Affiliation(s)
- William S DeWitt
- Adaptive Biotechnologies, Seattle, WA 98102.,Computational Biology Program, Fred Hutchinson Cancer Research Center, Seattle, WA 98109.,Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Krystle K Q Yu
- Department of Medicine, University of Washington, Seattle, WA 98195
| | - Damien B Wilburn
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | | | | | - Cheryl L Day
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322.,Emory Vaccine Center, Atlanta, GA 30329
| | - Thomas J Scriba
- South African Tuberculosis Vaccine Initiative, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town 7925, South Africa.,Division of Immunology, Department of Pathology, University of Cape Town, Cape Town 7925, South Africa
| | - Harlan S Robins
- Adaptive Biotechnologies, Seattle, WA 98102.,Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109
| | - Willie J Swanson
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | | | - Philip H Bradley
- Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109; and.,Institute for Protein Design, University of Washington, Seattle, WA 98195
| | - Chetan Seshadri
- Department of Medicine, University of Washington, Seattle, WA 98195;
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12
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Shahine A, Van Rhijn I, Cheng TY, Iwany S, Gras S, Moody DB, Rossjohn J. A molecular basis of human T cell receptor autoreactivity toward self-phospholipids. Sci Immunol 2018; 2:2/16/eaao1384. [PMID: 29054999 PMCID: PMC6649662 DOI: 10.1126/sciimmunol.aao1384] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Accepted: 08/25/2017] [Indexed: 12/14/2022]
Abstract
Human T cell autoreactivity toward lipid antigens presented by CD1 proteins can manifest in numerous diseases, including psoriasis, contact hypersensitivities, and allergies. However, the molecular mechanisms for regulating T cell autoreactivity toward lipid antigens remain unclear. We determined the basis for T cell receptor (TCR) autoreactivity toward CD1b bound to self-phospholipids. The spectrum of self-antigens captured by CD1b skews toward abundant membrane phospholipids such as phosphatidylcholine and phosphatidylethanolamine. However, TCRs can specifically recognize rare phospholipids, including phosphatidylglycerol (PG). The structure of an autoreactive TCR bound to CD1b-PG shows that discrimination occurs through a marked induced fit movement of PG so that its polar head group fits snugly into the cationic cup of the TCR. Conversely, TCR binding toward ubiquitous self-phospholipids was sterically or electrostatically repelled. Accordingly, we describe a mechanism of TCR autoreactivity toward rare phospholipids and avoidance of autoreactivity to the most abundant self-phospholipids.
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Affiliation(s)
- Adam Shahine
- Infection and Immunity Program and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia.,Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Victoria 3800, Australia
| | - Ildiko Van Rhijn
- Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.,Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 1, 3584CL Utrecht, Netherlands
| | - Tan-Yun Cheng
- Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Sarah Iwany
- Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Stephanie Gras
- Infection and Immunity Program and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia. .,Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Victoria 3800, Australia
| | - D Branch Moody
- Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
| | - Jamie Rossjohn
- Infection and Immunity Program and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia. .,Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Victoria 3800, Australia.,Institute of Infection and Immunity, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK
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13
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Lepore M, Mori L, De Libero G. The Conventional Nature of Non-MHC-Restricted T Cells. Front Immunol 2018; 9:1365. [PMID: 29963057 PMCID: PMC6010553 DOI: 10.3389/fimmu.2018.01365] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 06/01/2018] [Indexed: 12/17/2022] Open
Abstract
The definition “unconventional T cells” identifies T lymphocytes that recognize non-peptide antigens presented by monomorphic antigen-presenting molecules. Two cell populations recognize lipid antigens and small metabolites presented by CD1 and MR1 molecules, respectively. A third cell population expressing the TCR Vγ9Vδ2 is stimulated by small phosphorylated metabolites. In the recent past, we have learnt a lot about the selection, tissue distribution, gene transcription programs, mode of expansion after antigen recognition, and persistence of these cells. These studies depict their functions in immune homeostasis and diseases. Current investigations are revealing that unconventional T cells include distinct sub-populations, which display unexpected similarities to classical MHC-restricted T cells in terms of TCR repertoire diversity, antigen specificity variety, functional heterogeneity, and naïve-to-memory differentiation dynamic. This review discusses the latest findings with a particular emphasis on these T cells, which appear to be more conventional than previously appreciated, and with the perspective of using CD1 and MR1-restricted T cells in vaccination and immunotherapy.
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Affiliation(s)
- Marco Lepore
- Experimental Immunology, Department of Biomedicine, University of Basel and University Hospital of Basel, Basel, Switzerland
| | - Lucia Mori
- Experimental Immunology, Department of Biomedicine, University of Basel and University Hospital of Basel, Basel, Switzerland
| | - Gennaro De Libero
- Experimental Immunology, Department of Biomedicine, University of Basel and University Hospital of Basel, Basel, Switzerland
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14
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Gras S, Van Rhijn I, Shahine A, Le Nours J. Molecular recognition of microbial lipid-based antigens by T cells. Cell Mol Life Sci 2018; 75:1623-1639. [PMID: 29340708 PMCID: PMC6328055 DOI: 10.1007/s00018-018-2749-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 12/17/2017] [Accepted: 01/08/2018] [Indexed: 02/06/2023]
Abstract
The immune system has evolved to protect hosts from pathogens. T cells represent a critical component of the immune system by their engagement in host defence mechanisms against microbial infections. Our knowledge of the molecular recognition by T cells of pathogen-derived peptidic antigens that are presented by the major histocompatibility complex glycoproteins is now well established. However, lipids represent an additional, distinct chemical class of molecules that when presented by the family of CD1 antigen-presenting molecules can serve as antigens, and be recognized by specialized subsets of T cells leading to antigen-specific activation. Over the past decades, numerous CD1-presented self- and bacterial lipid-based antigens have been isolated and characterized. However, our understanding at the molecular level of T cell immunity to CD1 molecules presenting microbial lipid-based antigens is still largely unexplored. Here, we review the insights and the molecular basis underpinning the recognition of microbial lipid-based antigens by T cells.
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Affiliation(s)
- Stephanie Gras
- Infection and Immunity Program and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
- Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, VIC, 3800, Australia
| | - Ildiko Van Rhijn
- Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital/Harvard Medical School, Boston, USA
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, University Utrecht, Utrecht, The Netherlands
| | - Adam Shahine
- Infection and Immunity Program and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
- Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, VIC, 3800, Australia
| | - Jérôme Le Nours
- Infection and Immunity Program and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia.
- Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, VIC, 3800, Australia.
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15
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Chancellor A, Gadola SD, Mansour S. The versatility of the CD1 lipid antigen presentation pathway. Immunology 2018; 154:196-203. [PMID: 29460282 DOI: 10.1111/imm.12912] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 02/12/2018] [Accepted: 02/14/2018] [Indexed: 12/19/2022] Open
Abstract
The family of non-classical major histocompatibility complex (MHC) class-I like CD1 molecules has an emerging role in human disease. Group 1 CD1 includes CD1a, CD1b and CD1c, which function to display lipids on the cell surface of antigen-presenting cells for direct recognition by T-cells. The recent advent of CD1 tetramers and the identification of novel lipid ligands has contributed towards the increasing number of CD1-restricted T-cell clones captured. These advances have helped to identify novel donor unrestricted and semi-invariant T-cell populations in humans and new mechanisms of T-cell recognition. However, although there is an opportunity to design broadly acting lipids and harness the therapeutic potential of conserved T-cells, knowledge of their role in health and disease is lacking. We briefly summarize the current evidence implicating group 1 CD1 molecules in infection, cancer and autoimmunity and show that although CD1 are not as diverse as MHC, recent discoveries highlight their versatility as they exhibit intricate mechanisms of antigen presentation.
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Affiliation(s)
- Andrew Chancellor
- Faculty of Medicine, Academic Unit of Clinical and Experimental Sciences, Southampton, UK
| | - Stephan D Gadola
- Faculty of Medicine, Academic Unit of Clinical and Experimental Sciences, Southampton, UK.,F.Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Salah Mansour
- Faculty of Medicine, Academic Unit of Clinical and Experimental Sciences, Southampton, UK
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16
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Chancellor A, Tocheva AS, Cave-Ayland C, Tezera L, White A, Al Dulayymi JR, Bridgeman JS, Tews I, Wilson S, Lissin NM, Tebruegge M, Marshall B, Sharpe S, Elliott T, Skylaris CK, Essex JW, Baird MS, Gadola S, Elkington P, Mansour S. CD1b-restricted GEM T cell responses are modulated by Mycobacterium tuberculosis mycolic acid meromycolate chains. Proc Natl Acad Sci U S A 2017; 114:E10956-E10964. [PMID: 29158404 PMCID: PMC5754766 DOI: 10.1073/pnas.1708252114] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Tuberculosis (TB), caused by Mycobacterium tuberculosis, remains a major human pandemic. Germline-encoded mycolyl lipid-reactive (GEM) T cells are donor-unrestricted and recognize CD1b-presented mycobacterial mycolates. However, the molecular requirements governing mycolate antigenicity for the GEM T cell receptor (TCR) remain poorly understood. Here, we demonstrate CD1b expression in TB granulomas and reveal a central role for meromycolate chains in influencing GEM-TCR activity. Meromycolate fine structure influences T cell responses in TB-exposed individuals, and meromycolate alterations modulate functional responses by GEM-TCRs. Computational simulations suggest that meromycolate chain dynamics regulate mycolate head group movement, thereby modulating GEM-TCR activity. Our findings have significant implications for the design of future vaccines that target GEM T cells.
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Affiliation(s)
- Andrew Chancellor
- Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, United Kingdom
- Public Health England, National Infections Service, Porton Down, Salisbury SP4 0JQ, United Kingdom
| | - Anna S Tocheva
- Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, United Kingdom
| | - Chris Cave-Ayland
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Liku Tezera
- Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, United Kingdom
| | - Andrew White
- Public Health England, National Infections Service, Porton Down, Salisbury SP4 0JQ, United Kingdom
| | - Juma'a R Al Dulayymi
- School of Chemistry, Bangor University, Bangor, Gwynedd LL57 2UW, United Kingdom
| | | | - Ivo Tews
- School of Biological Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
- Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Susan Wilson
- Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, United Kingdom
- Histochemistry Unit, University of Southampton, Southampton SO16 6YD, United Kingdom
| | | | - Marc Tebruegge
- Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, United Kingdom
- Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
- NIHR Southampton Biomedical Research Centre, Southampton SO17 1BJ, United Kingdom
- Global Health Research Institute, University of Southampton, Southampton SO17 1BJ, United Kingdom
- Department of Paediatrics, Faculty of Medicine, University of Melbourne, 3052 Parkville, Australia
- Department of Paediatric Infectious Diseases & Immunology, Evelina London Children's Hospital, Guy's and St. Thomas' NHS Foundation Trust, London SE1 7EH, United Kingdom
| | - Ben Marshall
- Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, United Kingdom
- Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
- NIHR Southampton Biomedical Research Centre, Southampton SO17 1BJ, United Kingdom
| | - Sally Sharpe
- Public Health England, National Infections Service, Porton Down, Salisbury SP4 0JQ, United Kingdom
| | - Tim Elliott
- Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
- Cancer Sciences Unit, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, United Kingdom
| | - Chris-Kriton Skylaris
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
- Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Jonathan W Essex
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
- Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Mark S Baird
- School of Chemistry, Bangor University, Bangor, Gwynedd LL57 2UW, United Kingdom
| | - Stephan Gadola
- Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, United Kingdom
- Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
- F. Hoffmann-La Roche Ltd., 4070 Basel, Switzerland
| | - Paul Elkington
- Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, United Kingdom
- Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
- NIHR Southampton Biomedical Research Centre, Southampton SO17 1BJ, United Kingdom
- Global Health Research Institute, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Salah Mansour
- Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, United Kingdom;
- Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
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17
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18
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Le Nours J, Shahine A, Gras S. Molecular features of lipid-based antigen presentation by group 1 CD1 molecules. Semin Cell Dev Biol 2017; 84:48-57. [PMID: 29113870 DOI: 10.1016/j.semcdb.2017.11.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 09/12/2017] [Accepted: 11/02/2017] [Indexed: 11/18/2022]
Abstract
Lipids are now widely considered to play a variety of important roles in T-cell mediated immunity, including serving as antigens. Lipid-based antigens are presented by a specialised group of glycoproteins termed CD1. In humans, three classes of CD1 molecules exist: group 1 (CD1a, CD1b, CD1c), group 2 (CD1d), and group 3 (CD1e). While CD1d-mediated T-cell immunity has been extensively investigated, we have only recently gained insights into the structure and function of group 1 CD1 molecules. Structural studies have revealed how lipid-based antigens are presented by group 1 CD1 molecules, as well as shedding light on the molecular requirements for T-cell recognition. Here, we provide an overview of our current understanding of lipid presentation by group 1 CD1 molecules in humans and their recognition by T-cells, as well as examining the potential differences in lipid presentation that may occur across different species.
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Affiliation(s)
- Jérôme Le Nours
- Infection and Immunity Program and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia; Australian Research Council Centre of Excellence for Advanced Molecular Imaging, Monash University, Clayton, Victoria 3800, Australia
| | - Adam Shahine
- Infection and Immunity Program and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia
| | - Stephanie Gras
- Infection and Immunity Program and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia; Australian Research Council Centre of Excellence for Advanced Molecular Imaging, Monash University, Clayton, Victoria 3800, Australia.
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19
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Van Rhijn I, Iwany SK, Fodran P, Cheng TY, Gapin L, Minnaard AJ, Moody DB. CD1b-mycolic acid tetramers demonstrate T-cell fine specificity for mycobacterial lipid tails. Eur J Immunol 2017; 47:1525-1534. [PMID: 28665555 DOI: 10.1002/eji.201747062] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 05/22/2017] [Accepted: 06/26/2017] [Indexed: 11/12/2022]
Abstract
Mycobacterium tuberculosis synthesizes a thick cell wall comprised of mycolic acids (MA), which are foreign antigens for human T cells. T-cell clones from multiple donors were used to determine the fine specificity of MA recognition by human αβ T cells. Most CD1-presented lipid antigens contain large hydrophilic head groups comprised of carbohydrates or peptides that dominate patterns of T-cell specificity. MA diverges from the consensus antigen motif in that it lacks a head group. Using multiple forms of natural and synthetic MA and MA-specific T-cells with different T-cell receptors, we found that, unlike antigens with larger head groups, lipid length strongly controlled T-cell responses to MA. In addition, the three forms of MA that naturally occur in M. tuberculosis that differ in modifications on the lipid tail, differ in their potency for activating MA-specific T-cell clones. Thus, naturally occurring MA forms should be considered as separate, partly cross-reactive antigens. Two of the three forms of MA could be loaded onto human CD1b proteins, creating working CD1b-MA tetramers. The creation of CD1b-MA tetramers represents a new tool for future studies that track the effector functions and kinetics of MA-specific T-cells ex vivo.
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Affiliation(s)
- Ildiko Van Rhijn
- Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.,Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Sarah K Iwany
- Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Peter Fodran
- Stratingh Institute for Chemistry, University of Groningen, Groningen, The Netherlands
| | - Tan-Yun Cheng
- Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Laurent Gapin
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus and National Jewish Health, Aurora, CO, USA
| | - Adriaan J Minnaard
- Stratingh Institute for Chemistry, University of Groningen, Groningen, The Netherlands
| | - D Branch Moody
- Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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20
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Four pathways of CD1 antigen presentation to T cells. Curr Opin Immunol 2017; 46:127-133. [PMID: 28756303 DOI: 10.1016/j.coi.2017.07.013] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 07/07/2017] [Accepted: 07/12/2017] [Indexed: 12/28/2022]
Abstract
CD1a, CD1b, CD1c and CD1d proteins migrate through distinct subcellular compartments of antigen presenting cells and so can be considered to take four separate pathways leading to display of lipid antigens to T cell receptors. This review discusses the intersection of CD1 trafficking and lipid antigen loading mechanisms in cells, highlighting key controversies relating to CD1 gene expression, size mismatches between antigens and CD1 binding clefts and unexpected mechanisms of T cell receptor-based recognition.
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21
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Kaczmarek R, Pasciak M, Szymczak-Kulus K, Czerwinski M. CD1: A Singed Cat of the Three Antigen Presentation Systems. Arch Immunol Ther Exp (Warsz) 2017; 65:201-214. [PMID: 28386696 PMCID: PMC5434122 DOI: 10.1007/s00005-017-0461-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 02/20/2017] [Indexed: 02/07/2023]
Abstract
Contrary to general view that the MHC Class I and II are the kapellmeisters of recognition and response to antigens, there is another big player in that part of immunity, represented by CD1 glycoproteins. In contrast to MHC Class I or II, which present peptides, CD1 molecules present lipids. Humans express five CD1 proteins (CD1a-e), four of which (CD1a-d) are trafficked to the cell surface, where they may display lipid antigens to T-cell receptors. This interaction may lead to both non-cognate and cognate T cell help to B cells, the latter eliciting anti-lipid antibody response. All CD1 proteins can bind a broad range of structurally different exogenous and endogenous lipids, but each shows a preference to one or more lipid classes. This unorthodox binding behavior is the result of elaborate architectures of CD1 binding clefts and distinct intracellular trafficking routes. Together, these features make CD1 system a versatile player in immune response, sitting at the crossroads of innate and adaptive immunity. While CD1 system may be involved in numerous infectious, inflammatory, and autoimmune diseases, its involvement may lead to opposite outcomes depending on different pathologies. Despite these ambiguities and complexity, CD1 system draws growing attention and continues to show glimmers of therapeutic potential. In this review, we summarize the current knowledge about CD1 proteins, their structures, lipid-binding profiles, and roles in immunity, and evaluate the role of CD1 proteins in eliciting humoral immune response.
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Affiliation(s)
- Radoslaw Kaczmarek
- Laboratory of Glycoconjugate Immunochemistry, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wrocław, Poland
| | - Mariola Pasciak
- Laboratory of Medical Microbiology, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wrocław, Poland
| | - Katarzyna Szymczak-Kulus
- Laboratory of Glycoconjugate Immunochemistry, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wrocław, Poland
| | - Marcin Czerwinski
- Laboratory of Glycoconjugate Immunochemistry, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wrocław, Poland. .,Faculty of Physiotherapy and Physical Education, Opole University of Technology, Opole, Poland.
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22
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CD1-Restricted T Cells at the Crossroad of Innate and Adaptive Immunity. J Immunol Res 2016; 2016:2876275. [PMID: 28070524 PMCID: PMC5192300 DOI: 10.1155/2016/2876275] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 11/13/2016] [Indexed: 11/17/2022] Open
Abstract
Lipid-specific T cells comprise a group of T cells that recognize lipids bound to the MHC class I-like CD1 molecules. There are four isoforms of CD1 that are expressed at the surface of antigen presenting cells and therefore capable of presenting lipid antigens: CD1a, CD1b, CD1c, and CD1d. Each one of these isoforms has distinct structural features and cellular localizations, which promotes binding to a broad range of different types of lipids. Lipid antigens originate from either self-tissues or foreign sources, such as bacteria, fungus, or plants and their recognition by CD1-restricted T cells has important implications in infection but also in cancer and autoimmunity. In this review, we describe the characteristics of CD1 molecules and CD1-restricted lipid-specific T cells, highlighting the innate-like and adaptive-like features of different CD1-restricted T cell subtypes.
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23
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T cell receptor recognition of CD1b presenting a mycobacterial glycolipid. Nat Commun 2016; 7:13257. [PMID: 27807341 PMCID: PMC5095289 DOI: 10.1038/ncomms13257] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 09/15/2016] [Indexed: 01/15/2023] Open
Abstract
CD1 proteins present microbial lipids to T cells. Germline-encoded mycolyl lipid-reactive (GEM) T cells with conserved αβ T cell receptors (TCRs) recognize CD1b presenting mycobacterial mycolates. As the molecular basis underpinning TCR recognition of CD1b remains unknown, here we determine the structure of a GEM TCR bound to CD1b presenting glucose-6-O-monomycolate (GMM). The GEM TCR docks centrally above CD1b, whereby the conserved TCR α-chain extensively contacts CD1b and GMM. Through mutagenesis and study of T cells from tuberculosis patients, we identify a consensus CD1b footprint of TCRs present among GEM T cells. Using both the TCR α- and β-chains as tweezers to surround and grip the glucose moiety of GMM, GEM TCRs create a highly specific mechanism for recognizing this mycobacterial glycolipid. Germline-encoded mycolyl lipid-reactive (GEM) T cells recognize CD1b proteins presenting mycobacterial mycolates via their T-cell receptors (TCRs). Here, the authors present the structure of this interaction and provide a molecular basis for the co-recognition of CD1b and a mycobacterial glycolipid.
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24
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Huang S, Moody DB. Donor-unrestricted T cells in the human CD1 system. Immunogenetics 2016; 68:577-96. [PMID: 27502318 PMCID: PMC5915868 DOI: 10.1007/s00251-016-0942-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 07/14/2016] [Indexed: 02/06/2023]
Abstract
The CD1 and MHC systems are specialized for lipid and peptide display, respectively. Here, we review evidence showing how cellular CD1a, CD1b, CD1c, and CD1d proteins capture and display many cellular lipids to T cell receptors (TCRs). Increasing evidence shows that CD1-reactive T cells operate outside two classical immunogenetic concepts derived from the MHC paradigm. First, because CD1 proteins are non-polymorphic in human populations, T cell responses are not restricted to the donor's genetic background. Second, the simplified population genetics of CD1 antigen-presenting molecules can lead to simplified patterns of TCR usage. As contrasted with donor-restricted patterns of MHC-TCR interaction, the donor-unrestricted nature of CD1-TCR interactions raises the prospect that lipid agonists and antagonists of T cells could be developed.
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Affiliation(s)
- Shouxiong Huang
- Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA.
| | - D Branch Moody
- Divison of Rheumatology, Immunology and Allergy, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
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25
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Zajonc DM. The CD1 family: serving lipid antigens to T cells since the Mesozoic era. Immunogenetics 2016; 68:561-76. [PMID: 27368414 DOI: 10.1007/s00251-016-0931-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 06/22/2016] [Indexed: 12/20/2022]
Abstract
Class I-like CD1 molecules are in a family of antigen-presenting molecules that bind lipids and lipopeptides, rather than peptides for immune surveillance by T cells. Since CD1 lacks the high degree of polymorphism found in their major histocompatibility complex (MHC) class I molecules, different species express different numbers of CD1 isotypes, likely to be able to present structurally diverse classes of lipid antigens. In this review, we will present a historical overview of the structures of the different human CD1 isotypes and also discuss species-specific adaptations of the lipid-binding groove. We will discuss how single amino acid changes alter the shape and volume of the CD1 binding groove, how these minor changes can give rise to different numbers of binding pockets, and how these pockets affect the lipid repertoire that can be presented by any given CD1 protein. We will compare the structures of various lipid antigens and finally, we will discuss recognition of CD1-presented lipid antigens by antigen receptors on T cells (TCRs).
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Affiliation(s)
- Dirk M Zajonc
- Division of Cell Biology, La Jolla Institute for Allergy and Immunology (LJI), La Jolla, CA, 92037, USA. .,Department of Internal Medicine, Faculty of Medicine and Health Sciences, Ghent University, 9000, Ghent, Belgium.
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26
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Sun L, Middleton DR, Wantuch PL, Ozdilek A, Avci FY. Carbohydrates as T-cell antigens with implications in health and disease. Glycobiology 2016; 26:1029-1040. [PMID: 27236197 DOI: 10.1093/glycob/cww062] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Revised: 05/11/2016] [Accepted: 05/23/2016] [Indexed: 12/27/2022] Open
Abstract
Glycosylation is arguably the most ubiquitous post-translational modification on proteins in microbial and mammalian cells. During the past few years, there has been intensive research demonstrating that carbohydrates, either in pure forms or in conjunction with proteins or lipids, evoke and modulate adaptive immune responses. We now know that carbohydrates can be directly recognized by T cells or participate in T-cell stimulation as components of T-cell epitopes. T-cell recognition of carbohydrate antigens takes place via their presentation by major histocompatibility complex pathways on antigen-presenting cells. In this review, we summarize studies on carbohydrates as T-cell antigens modulating adaptive immune responses. Through discussion of glycan-containing antigens, such as glycoproteins, glycolipids, zwitterionic polysaccharides and carbohydrate-based glycoconjugate vaccines, we will illustrate the key molecular and cellular interactions between carbohydrate antigens and T cells and the implications of these interactions in health and disease.
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Affiliation(s)
- Lina Sun
- Department of Biochemistry and Molecular Biology, Center for Molecular Medicine, and Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | - Dustin R Middleton
- Department of Biochemistry and Molecular Biology, Center for Molecular Medicine, and Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | - Paeton L Wantuch
- Department of Biochemistry and Molecular Biology, Center for Molecular Medicine, and Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | - Ahmet Ozdilek
- Department of Biochemistry and Molecular Biology, Center for Molecular Medicine, and Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | - Fikri Y Avci
- Department of Biochemistry and Molecular Biology, Center for Molecular Medicine, and Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
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27
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Mansour S, Tocheva AS, Cave-Ayland C, Machelett MM, Sander B, Lissin NM, Molloy PE, Baird MS, Stübs G, Schröder NWJ, Schumann RR, Rademann J, Postle AD, Jakobsen BK, Marshall BG, Gosain R, Elkington PT, Elliott T, Skylaris CK, Essex JW, Tews I, Gadola SD. Cholesteryl esters stabilize human CD1c conformations for recognition by self-reactive T cells. Proc Natl Acad Sci U S A 2016; 113:E1266-75. [PMID: 26884207 PMCID: PMC4780616 DOI: 10.1073/pnas.1519246113] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Cluster of differentiation 1c (CD1c)-dependent self-reactive T cells are abundant in human blood, but self-antigens presented by CD1c to the T-cell receptors of these cells are poorly understood. Here we present a crystal structure of CD1c determined at 2.4 Å revealing an extended ligand binding potential of the antigen groove and a substantially different conformation compared with known CD1c structures. Computational simulations exploring different occupancy states of the groove reenacted these different CD1c conformations and suggested cholesteryl esters (CE) and acylated steryl glycosides (ASG) as new ligand classes for CD1c. Confirming this, we show that binding of CE and ASG to CD1c enables the binding of human CD1c self-reactive T-cell receptors. Hence, human CD1c adopts different conformations dependent on ligand occupancy of its groove, with CE and ASG stabilizing CD1c conformations that provide a footprint for binding of CD1c self-reactive T-cell receptors.
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Affiliation(s)
- Salah Mansour
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO17 1BJ, United Kingdom; Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom;
| | - Anna S Tocheva
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Chris Cave-Ayland
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Moritz M Machelett
- Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom; Centre for Biological Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Barbara Sander
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | | | - Peter E Molloy
- Immunocore Limited, Abingdon, Oxon OX14 4RY, United Kingdom
| | - Mark S Baird
- School of Chemistry, Bangor University, Bangor, Gwynedd LL57 2DG, United Kingdom
| | - Gunthard Stübs
- Institute for Community Medicine, University Medicine Greifswald, 17489 Greifswald, Germany
| | - Nicolas W J Schröder
- Institute for Pathology, Otto-von-Guericke University Magdeburg, 39106 Magdeburg, Germany
| | - Ralf R Schumann
- Institute for Microbiology and Hygiene, Charité University Medical Center, 10117 Berlin, Germany
| | - Jörg Rademann
- Division of Medicinal Chemistry, Institute of Pharmacy, Freie Universität Berlin, 14195 Berlin, Germany
| | - Anthony D Postle
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | | | - Ben G Marshall
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO17 1BJ, United Kingdom; Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Rajendra Gosain
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Paul T Elkington
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO17 1BJ, United Kingdom; Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Tim Elliott
- Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom; Cancer Sciences Unit, Faculty of Medicine, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Chris-Kriton Skylaris
- Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom; School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Jonathan W Essex
- Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom; School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Ivo Tews
- Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom; Centre for Biological Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Stephan D Gadola
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO17 1BJ, United Kingdom; Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom; Novartis Institutes of Biomedical Research, 4058 Basel, Switzerland
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Smith DG, Williams SJ. Immune sensing of microbial glycolipids and related conjugates by T cells and the pattern recognition receptors MCL and Mincle. Carbohydr Res 2016; 420:32-45. [DOI: 10.1016/j.carres.2015.11.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 11/24/2015] [Accepted: 11/28/2015] [Indexed: 10/22/2022]
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Li W, Gu S, Fleming J, Bi L. Crystal structure of FadD32, an enzyme essential for mycolic acid biosynthesis in mycobacteria. Sci Rep 2015; 5:15493. [PMID: 26628098 PMCID: PMC4667280 DOI: 10.1038/srep15493] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 09/04/2015] [Indexed: 02/01/2023] Open
Abstract
Fatty acid degradation protein D32 (FadD32), an enzyme required for mycolic acid biosynthesis and essential for mycobacterial growth, has recently been identified as a valid and promising target for anti-tuberculosis drug development. Here we report the crystal structures of Mycobacterium smegmatis FadD32 in the apo and ATP-bound states at 2.4 Å and 2.25 Å resolution, respectively. FadD32 consists of two globular domains connected by a flexible linker. ATP binds in a cleft at the interface between the N- and C-terminal domains and its binding induces significant local conformational changes in FadD32. The binding sites of meromycolic acid and phosphopantetheine are identified by structural comparison with other members of the adenylating enzyme superfamily. These results will improve our understanding of the catalytic mechanism of FadD32 and help in the design of inhibitors of this essential enzyme.
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Affiliation(s)
- Wenjuan Li
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Shoujin Gu
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Joy Fleming
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Lijun Bi
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
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Dellabona P, Consonni M, de Lalla C, Casorati G. Group 1 CD1-restricted T cells and the pathophysiological implications of self-lipid antigen recognition. ACTA ACUST UNITED AC 2015; 86:393-405. [PMID: 26514448 DOI: 10.1111/tan.12689] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
T cell responses are generally regarded as specific for protein-derived peptide antigens. This is based on the molecular paradigm dictated by the T cell receptor (TCR) recognition of peptide-major histocompatibility complexs, which provides the molecular bases of the specificity and restriction of the T cell responses. An increasing number of findings in the last 20 years have challenged this paradigm, by showing the existence of T cells specific for lipid antigens presented by CD1 molecules. CD1-restricted T cells have been proven to be frequent components of the immune system and to recognize exogenous lipids, derived from pathogenic bacteria, as well as cell-endogenous self-lipids. This represents a young and exciting area of research in immunology with intriguing biological bases and a potential direct impact on human health.
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Affiliation(s)
- P Dellabona
- Experimental Immunology Unit, Division of Immunology, Transplantation and Infectious Diseases, San Raffaele Scientific Institute, Milano, Italy
| | - M Consonni
- Experimental Immunology Unit, Division of Immunology, Transplantation and Infectious Diseases, San Raffaele Scientific Institute, Milano, Italy
| | - C de Lalla
- Experimental Immunology Unit, Division of Immunology, Transplantation and Infectious Diseases, San Raffaele Scientific Institute, Milano, Italy
| | - G Casorati
- Experimental Immunology Unit, Division of Immunology, Transplantation and Infectious Diseases, San Raffaele Scientific Institute, Milano, Italy
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Abstract
The structure and amino acid diversity of the T-cell receptor (TCR), similar in nature to that of Fab portions of antibodies, would suggest that these proteins have a nearly infinite capacity to recognize antigen. Yet all currently defined native T cells expressing an α and β chain in their TCR can only sense antigen when presented in the context of a major histocompatibility complex (MHC) molecule. This MHC molecule can be one of many that exist in vertebrates, presenting small peptide fragments, lipid molecules, or small molecule metabolites. Here we review the pattern of TCR recognition of MHC molecules throughout a broad sampling of species and T-cell lineages and also touch upon T cells that do not appear to require MHC presentation for their surveillance function. We review the diversity of MHC molecules and information on the corresponding T-cell lineages identified in divergent species. We also discuss TCRs with structural domains unlike that of conventional TCRs of mouse and human. By presenting this broad view of TCR sequence, structure, domain organization, and function, we seek to explore how this receptor has evolved across time and been selected for alternative antigen-recognition capabilities in divergent lineages.
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Affiliation(s)
- Caitlin C. Castro
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA
- Committee on Immunology, University of Chicago, Chicago, IL, USA
| | - Adrienne M. Luoma
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA
- Committee on Immunology, University of Chicago, Chicago, IL, USA
| | - Erin J. Adams
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA
- Committee on Immunology, University of Chicago, Chicago, IL, USA
- Committee on Cancer Biology, University of Chicago, Chicago, IL, USA
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32
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Salio M, Cerundolo V. Regulation of Lipid Specific and Vitamin Specific Non-MHC Restricted T Cells by Antigen Presenting Cells and Their Therapeutic Potentials. Front Immunol 2015; 6:388. [PMID: 26284072 PMCID: PMC4517378 DOI: 10.3389/fimmu.2015.00388] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 07/13/2015] [Indexed: 12/17/2022] Open
Abstract
Since initial reports, more than 25 years ago, that T cells recognize lipids in the context on non-polymorphic CD1 molecules, our understanding of antigen presentation to non-peptide-specific T cell populations has deepened. It is now clear that αβ T cells bearing semi-invariant T cell receptor, as well as subsets of γδ T cells, recognize a variety of self and non-self lipids and contribute to shaping immune responses via cross talk with dendritic cells and B cells. Furthermore, it has been demonstrated that small molecules derived from the microbial riboflavin biosynthetic pathway (vitamin B2) bind monomorphic MR1 molecules and activate mucosal-associated invariant T cells, another population of semi-invariant T cells. Novel insights in the biological relevance of non-peptide-specific T cells have emerged with the development of tetrameric CD1 and MR1 molecules, which has allowed accurate enumeration and functional analysis of CD1- and MR1-restricted T cells in humans and discovery of novel populations of semi-invariant T cells. The phenotype and function of non-peptide-specific T cells will be discussed in the context of the known distribution of CD1 and MR1 molecules by different subsets of antigen-presenting cells at steady state and following infection. Concurrent modulation of CD1 transcription and lipid biosynthetic pathways upon TLR stimulation, coupled with efficient lipid antigen processing, result in the increased cell surface expression of antigenic CD1-lipid complexes. Similarly, MR1 expression is almost undetectable in resting APC and it is upregulated following bacterial infection, likely due to stabilization of MR1 molecules by microbial antigens. The tight regulation of CD1 and MR1 expression at steady state and during infection may represent an important mechanism to limit autoreactivity, while promoting T cell responses to foreign antigens.
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Affiliation(s)
- Mariolina Salio
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Vincenzo Cerundolo
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
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33
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Siddiqui S, Visvabharathy L, Wang CR. Role of Group 1 CD1-Restricted T Cells in Infectious Disease. Front Immunol 2015; 6:337. [PMID: 26175733 PMCID: PMC4484338 DOI: 10.3389/fimmu.2015.00337] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 06/16/2015] [Indexed: 12/12/2022] Open
Abstract
The evolutionarily conserved CD1 family of antigen-presenting molecules presents lipid antigens rather than peptide antigens to T cells. CD1 molecules, unlike classical MHC molecules, display limited polymorphism, making CD1-restricted lipid antigens attractive vaccine targets that could be recognized in a genetically diverse human population. Group 1 CD1 (CD1a, CD1b, and CD1c)-restricted T cells have been implicated to play critical roles in a variety of autoimmune and infectious diseases. In this review, we summarize current knowledge and recent discoveries on the development of group 1 CD1-restricted T cells and their function in different infection models. In particular, we focus on (1) newly identified microbial and self-lipid antigens, (2) kinetics, phenotype, and unique properties of group 1 CD1-restricted T cells during infection, and (3) the similarities of group 1 CD1-restricted T cells to the closely related group 2 CD1-restricted T cells.
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Affiliation(s)
- Sarah Siddiqui
- Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine , Chicago, IL , USA
| | - Lavanya Visvabharathy
- Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine , Chicago, IL , USA
| | - Chyung-Ru Wang
- Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine , Chicago, IL , USA
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34
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Abstract
For decades, proteins were thought to be the sole or at least the dominant source of antigens for T cells. Studies in the 1990s demonstrated that CD1 proteins and mycobacterial lipids form specific targets of human αβ T cells. The molecular basis by which T-cell receptors (TCRs) recognize CD1-lipid complexes is now well understood. Many types of mycobacterial lipids function as antigens in the CD1 system, and new studies done with CD1 tetramers identify T-cell populations in the blood of tuberculosis patients. In human populations, a fundamental difference between the CD1 and major histocompatibility complex systems is that all humans express nearly identical CD1 proteins. Correspondingly, human CD1 responsive T cells show evidence of conserved TCRs. In addition to natural killer T cells and mucosal-associated invariant T (MAIT cells), conserved TCRs define other subsets of human T cells, including germline-encoded mycolyl-reactive (GEM) T cells. The simple immunogenetics of the CD1 system and new investigative tools to measure T-cell responses in humans now creates a situation in which known lipid antigens can be developed as immunodiagnostic and immunotherapeutic reagents for tuberculosis disease.
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Affiliation(s)
- Ildiko Van Rhijn
- Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA; Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
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35
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Layre E, de Jong A, Moody DB. Human T cells use CD1 and MR1 to recognize lipids and small molecules. Curr Opin Chem Biol 2014; 23:31-8. [DOI: 10.1016/j.cbpa.2014.09.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 08/28/2014] [Accepted: 09/10/2014] [Indexed: 12/13/2022]
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Nakamura T, Fukiage M, Suzuki Y, Yano I, Miyazaki J, Nishiyama H, Akaza H, Harashima H. Mechanism responsible for the antitumor effect of BCG-CWS using the LEEL method in a mouse bladder cancer model. J Control Release 2014; 196:161-7. [PMID: 25315488 DOI: 10.1016/j.jconrel.2014.10.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2014] [Revised: 09/26/2014] [Accepted: 10/06/2014] [Indexed: 10/24/2022]
Abstract
We previously reported on the development of a water soluble formulation of the cell wall skeleton of BCG (BCG-CWS), a major immune active center of BCG, by encapsulating it into a nanoparticle (CWS-NP). The CWS-NP allowed us to clarify the machinery associated with the BCG mediated anti-bladder tumor effect, especially the roles of bladder cancer cells and dendritic cells (DCs) in the initial step, which remains poorly understood. We show herein that the internalization of BCG-CWS by bladder cancer cells, but not DCs, is indispensable for the induction of an antitumor effect against bladder cancer. Tumor growth was significantly inhibited in mice that had been inoculated with mouse bladder cancer (MBT-2) cells containing internalized BCG-CWS. On the other hand, the internalization of BCG-CWS by DCs had only a minor effect on inducing an antitumor effect against MBT-2 tumors. This was clarified for the first time by using the CWS-NP. This finding provides insights into our understanding of the role of bladder cancer cells and DCs in BCG therapy against bladder cancer.
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Affiliation(s)
- Takashi Nakamura
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
| | - Masafumi Fukiage
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
| | - Yoshiteru Suzuki
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
| | - Ikuya Yano
- Japan BCG Central Laboratory, Kiyose, Japan
| | - Jun Miyazaki
- Department of Urology, Faculty of Medicine, Tsukuba University, Tsukuba, Japan
| | - Hiroyuki Nishiyama
- Department of Urology, Faculty of Medicine, Tsukuba University, Tsukuba, Japan
| | - Hideyuki Akaza
- The University of Tokyo, Research Center for Advanced Science and Technology, Tokyo, Japan
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37
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Pierce BG, Vreven T, Weng Z. Modeling T cell receptor recognition of CD1-lipid and MR1-metabolite complexes. BMC Bioinformatics 2014; 15:319. [PMID: 25260513 PMCID: PMC4261541 DOI: 10.1186/1471-2105-15-319] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2014] [Accepted: 09/22/2014] [Indexed: 11/10/2022] Open
Abstract
Background T cell receptors (TCRs) can recognize diverse lipid and metabolite antigens presented by MHC-like molecules CD1 and MR1, and the molecular basis of many of these interactions has not been determined. Here we applied our protein docking algorithm TCRFlexDock, previously developed to perform docking of TCRs to peptide-MHC (pMHC) molecules, to predict the binding of αβ and γδ TCRs to CD1 and MR1, starting with the structures of the unbound molecules. Results Evaluating against TCR-CD1d complexes with crystal structures, we achieved near-native structures in the top 20 models for two out of four cases, and an acceptable-rated prediction for a third case. We also predicted the structure of an interaction between a MAIT TCR and MR1-antigen that has not been structurally characterized, yielding a top-ranked model that agreed remarkably with a characterized TCR-MR1-antigen structure that has a nearly identical TCR α chain but a different β chain, highlighting the likely dominance of the conserved α chain in MR1-antigen recognition. Docking performance was improved by re-training our scoring function with a set of TCR-pMHC complexes, and for a case with an outlier binding mode, we found that alternative docking start positions improved predictive accuracy. We then performed unbound docking with two mycolyl-lipid specific TCRs that recognize lipid-bound CD1b, which represent a class of interactions that is not structurally characterized. Highly-ranked models of these complexes showed remarkable agreement between their binding topologies, as expected based on their shared germline sequences, while differences in residue-level interactions with their respective antigens point to possible mechanisms underlying their distinct specificities. Conclusions Together these results indicate that flexible docking simulations can provide accurate models and atomic-level insights into TCR recognition of MHC-like molecules presenting lipid and other small molecule antigens. Electronic supplementary material The online version of this article (doi:10.1186/1471-2105-15-319) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Brian G Pierce
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA 01605, USA.
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38
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The CD1 size problem: lipid antigens, ligands, and scaffolds. Cell Mol Life Sci 2014; 71:3069-79. [PMID: 24658584 DOI: 10.1007/s00018-014-1603-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 02/10/2014] [Accepted: 03/06/2014] [Indexed: 01/17/2023]
Abstract
Whereas research on CD1d has emphasized a few glycosyl ceramides, the broader family of four human CD1 antigen-presenting molecules binds hundreds of distinct self-lipids. Individual lipid types bind within CD1 grooves in different ways, such that they partially fill the groove, match the groove volume, or protrude substantially from the groove. These differing modes of binding can now be connected to differing immunological functions, as individual lipids can act as stimulatory antigens, inhibitory ligands, or space-filling scaffolds. Because each type of CD1 protein folds to produce antigen-binding grooves with differing sizes and shapes, CD1a, CD1b, CD1c, CD1d, and CD1e have distinct mechanisms of capturing self-lipids and exchanging them for foreign lipids. The size discrepancy between endogeneous lipids and groove volume is most pronounced for CD1b. Recent studies show that the large CD1b cavity can simultaneously bind two self-lipids, the antigen, and its scaffold lipid, which can be exchanged for one large bacterial lipid. In this review, we will highlight recent studies showing how cells regulate lipid antigen loading and the roles CD1 groove structures have in control of the presentation of chemically diverse lipids to T cells.
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Thirunavukkarasu S, de Silva K, Plain KM, J Whittington R. Role of host- and pathogen-associated lipids in directing the immune response in mycobacterial infections, with emphasis on Mycobacterium avium subsp. paratuberculosis. Crit Rev Microbiol 2014; 42:262-75. [PMID: 25163812 DOI: 10.3109/1040841x.2014.932327] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Mycobacteria have a complex cell wall with a high lipid content that confers unique advantages for bacterial survival in the hostile host environment, leading to long-term infection. There is a wealth of evidence suggesting the role cell wall-associated lipid antigens play at the host-pathogen interface by contributing to bacterial virulence. One pathway that pathogenic mycobacteria use to subvert host immune pathways to their advantage is host cholesterol/lipid homeostasis. This review focuses on the possible role of pathogen- and host-associated lipids in the survival and persistence of pathogenic mycobacteria with emphasis on Mycobacterium avium subsp. paratuberculosis. We draw upon literature in diverse areas of infectious and metabolic diseases and explain a mechanism by which mycobacterial-induced changes in the host cellular energy state could account for phenomena that are a hallmark of chronic mycobacterial diseases.
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Affiliation(s)
| | - Kumudika de Silva
- a Faculty of Veterinary Science , University of Sydney , Camden , Australia
| | - Karren M Plain
- a Faculty of Veterinary Science , University of Sydney , Camden , Australia
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40
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De Libero G, Singhal A, Lepore M, Mori L. Nonclassical T cells and their antigens in tuberculosis. Cold Spring Harb Perspect Med 2014; 4:a018473. [PMID: 25059739 DOI: 10.1101/cshperspect.a018473] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
T cells that recognize nonpeptidic antigens, and thereby are identified as nonclassical, represent important yet poorly characterized effectors of the immune response. They are present in large numbers in circulating blood and tissues and are as abundant as T cells recognizing peptide antigens. Nonclassical T cells exert multiple functions including immunoregulation, tumor control, and protection against infections. They recognize complexes of nonpeptidic antigens such as lipid and glycolipid molecules, vitamin B2 precursors, and phosphorylated metabolites of the mevalonate pathway. Each of these antigens is presented by antigen-presenting molecules other than major histocompatibility complex (MHC), including CD1, MHC class I-related molecule 1 (MR1), and butyrophilin 3A1 (BTN3A1) molecules. Here, we discuss how nonclassical T cells participate in the recognition of mycobacterial antigens and in the mycobacterial-specific immune response.
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Affiliation(s)
- Gennaro De Libero
- SIgN (Singapore Immunology Network), A*STAR (Agency for Science, Technology and Research), 138648 Singapore Experimental Immunology, Department of Biomedicine, University Hospital Basel, CH-4031 Basel, Switzerland
| | - Amit Singhal
- SIgN (Singapore Immunology Network), A*STAR (Agency for Science, Technology and Research), 138648 Singapore
| | - Marco Lepore
- Experimental Immunology, Department of Biomedicine, University Hospital Basel, CH-4031 Basel, Switzerland
| | - Lucia Mori
- SIgN (Singapore Immunology Network), A*STAR (Agency for Science, Technology and Research), 138648 Singapore Experimental Immunology, Department of Biomedicine, University Hospital Basel, CH-4031 Basel, Switzerland
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41
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De Libero G, Mori L. The T-Cell Response to Lipid Antigens of Mycobacterium tuberculosis. Front Immunol 2014; 5:219. [PMID: 24904574 PMCID: PMC4033098 DOI: 10.3389/fimmu.2014.00219] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 04/30/2014] [Indexed: 11/13/2022] Open
Abstract
T-cells recognize lipid antigens presented by dedicated antigen-presenting molecules that belong to the CD1 family. This review discusses the structural properties of CD1 molecules, the nature of mycobacterial lipid antigens, and the phenotypic and functional properties of T-cells recognizing mycobacterial lipids. In humans, the five CD1 genes encode structurally similar glycoproteins that recycle in and thus survey different cellular endosomal compartments. The structure of the CD1-lipid-binding pockets, their mode of intracellular recycling and the type of CD1-expressing antigen-presenting cells all contribute to diversify lipid immunogenicity and presentation to T-cells. Mycobacteria produce a large variety of lipids, which form stable complexes with CD1 molecules and stimulate specific T-cells. The structures of antigenic lipids may be greatly different from each other and each lipid may induce unique T-cells capable of discriminating small lipid structural changes. The important functions of some lipid antigens within mycobacterial cells prevent the generation of negative mutants capable of escaping this type of immune response. T-cells specific for lipid antigens are stimulated in tuberculosis and exert protective functions. The mechanisms of antigen recognition, the type of effector functions and the mode of lipid-specific T-cell priming are discussed, emphasizing recent evidence of the roles of lipid-specific T-cells in tuberculosis.
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Affiliation(s)
- Gennaro De Libero
- Singapore Immunology Network, Agency for Science, Technology and Research (ASTAR) , Singapore , Singapore ; Experimental Immunology, Department of Biomedicine, University Hospital Basel , Basel , Switzerland
| | - Lucia Mori
- Singapore Immunology Network, Agency for Science, Technology and Research (ASTAR) , Singapore , Singapore
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42
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Abstract
Over the past 15 years, investigators have shown that T lymphocytes can recognize not only peptides in the context of MHC class I and class II molecules but also foreign and self-lipids in association with the nonclassical MHC class I-like molecules, CD1 proteins. In this review, we describe the most recent events in the field, with particular emphasis on (a) structural and functional aspects of lipid presentation by CD1 molecules, (b) the development of CD1d-restricted invariant natural killer T (iNKT) cells and transcription factors required for their differentiation, (c) the ability of iNKT cells to modulate innate and adaptive immune responses through their cross talk with lymphoid and myeloid cells, and (d) MR1-restricted and group I (CD1a, CD1b, and CD1c)-restricted T cells.
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Affiliation(s)
- Mariolina Salio
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DU, United Kingdom;
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Myelin recovery in multiple sclerosis: the challenge of remyelination. Brain Sci 2013; 3:1282-324. [PMID: 24961530 PMCID: PMC4061877 DOI: 10.3390/brainsci3031282] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 08/12/2013] [Accepted: 08/12/2013] [Indexed: 12/26/2022] Open
Abstract
Multiple sclerosis (MS) is the most common demyelinating and an autoimmune disease of the central nervous system characterized by immune-mediated myelin and axonal damage, and chronic axonal loss attributable to the absence of myelin sheaths. T cell subsets (Th1, Th2, Th17, CD8+, NKT, CD4+CD25+ T regulatory cells) and B cells are involved in this disorder, thus new MS therapies seek damage prevention by resetting multiple components of the immune system. The currently approved therapies are immunoregulatory and reduce the number and rate of lesion formation but are only partially effective. This review summarizes current understanding of the processes at issue: myelination, demyelination and remyelination—with emphasis upon myelin composition/architecture and oligodendrocyte maturation and differentiation. The translational options target oligodendrocyte protection and myelin repair in animal models and assess their relevance in human. Remyelination may be enhanced by signals that promote myelin formation and repair. The crucial question of why remyelination fails is approached is several ways by examining the role in remyelination of available MS medications and avenues being actively pursued to promote remyelination including: (i) cytokine-based immune-intervention (targeting calpain inhibition), (ii) antigen-based immunomodulation (targeting glycolipid-reactive iNKT cells and sphingoid mediated inflammation) and (iii) recombinant monoclonal antibodies-induced remyelination.
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Adams EJ, Luoma AM. The adaptable major histocompatibility complex (MHC) fold: structure and function of nonclassical and MHC class I-like molecules. Annu Rev Immunol 2013; 31:529-61. [PMID: 23298204 DOI: 10.1146/annurev-immunol-032712-095912] [Citation(s) in RCA: 138] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The MHC fold is found in proteins that have a range of functions in the maintenance of an organism's health, from immune regulation to fat metabolism. Well adapted for antigen presentation, as seen for peptides in the classical MHC molecules and for lipids in CD1 molecules, the MHC fold has also been modified to perform Fc-receptor activity (e.g., FcRn) and for roles in host homeostasis (e.g., with HFE and ZAG). The more divergent MHC-like molecules, such as some of those that interact with the NKG2D receptor, represent the minimal MHC fold, doing away with the α3 domain and β2m while maintaining the α1/α2 platform domain for receptor engagement. Viruses have also co-opted the MHC fold for immune-evasive functions. The variations on the theme of a β-sheet topped by two semiparallel α-helices are discussed in this review, highlighting the fantastic adaptability of this fold for good and for bad.
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Affiliation(s)
- Erin J Adams
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois 60637, USA.
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Van Rhijn I, Ly D, Moody DB. CD1a, CD1b, and CD1c in immunity against mycobacteria. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 783:181-97. [PMID: 23468110 DOI: 10.1007/978-1-4614-6111-1_10] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
The CD1 system is composed of five types of human CD1 proteins, CD1a, CD1b, CD1c, CD1d, and CD1e, and their mammalian orthologs. Each type of CD1 protein has a distinct antigen binding groove and shows differing patterns of expression within cells and in different tissues. Here we review the molecular mechanisms by which CD1a, CD1b, and CD1c capture distinct classes of self- and mycobacterial antigens. We discuss how CD1-restricted T cells participate in the immune response, emphasizing new evidence for mycobacterial recognition in vivo in human and non-human models.
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Affiliation(s)
- Ildiko Van Rhijn
- Division of Rheumatology, Harvard Medical School, Boston, MA, USA.
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Geerdink D, Horst BT, Lepore M, Mori L, Puzo G, Hirsch AKH, Gilleron M, de Libero G, Minnaard AJ. Total synthesis, stereochemical elucidation and biological evaluation of Ac2SGL; a 1,3-methyl branched sulfoglycolipid from Mycobacterium tuberculosis. Chem Sci 2013. [DOI: 10.1039/c2sc21620e] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Major T cell response to a mycolyl glycolipid is mediated by CD1c molecules in rhesus macaques. Infect Immun 2012; 81:311-6. [PMID: 23132493 DOI: 10.1128/iai.00871-12] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human CD1b molecules contain a maze of hydrophobic pockets and a tunnel capable of accommodating the unusually long, branched acyl chain of mycolic acids, an essential fatty acid component of the cell wall of mycobacteria. It has been accepted that CD1b-bound mycolic acids constitute a scaffold for mycolate-containing (glyco)lipids stimulating CD1b-restricted T cells. Remarkable homology in amino acid sequence is observed between human and monkey CD1b molecules, and indeed, monkey CD1b molecules are able to bind glucose monomycolate (GMM), a glucosylated species of mycolic acids, and present it to specific human T cells in vitro. Nevertheless, we found, unexpectedly, that Mycobacterium bovis bacillus Calmette-Guerin (BCG)-vaccinated monkeys exhibited GMM-specific T cell responses that were restricted by CD1c rather than CD1b molecules. GMM-specific, CD1c-restricted T cells were detected in the circulation of all 4 rhesus macaque monkeys tested after but not before vaccination with BCG. The circulating GMM-specific T cells were detected broadly in both CD4(+) and CD8(+) cell populations, and upon antigenic stimulation, a majority of the GMM-specific T cells produced both gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α), two major host protective cytokines functioning against infection with mycobacteria. Furthermore, the GMM-specific T cells were able to extravasate and approach the site of infection where CD1c(+) cells accumulated. These observations indicate a previously inconceivable role for primate CD1c molecules in eliciting T cell responses to mycolate-containing antigens.
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Girardi E, Zajonc DM. Molecular basis of lipid antigen presentation by CD1d and recognition by natural killer T cells. Immunol Rev 2012; 250:167-79. [PMID: 23046129 PMCID: PMC3471380 DOI: 10.1111/j.1600-065x.2012.01166.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Together with peptides, T lymphocytes respond to hydrophobic molecules, mostly lipids, presented by the non-classical CD1 family (CD1a-e). These molecules have evolved complex and diverse binding grooves in order to survey different cellular compartments for self and exogenous antigens, which are then presented for recognition to T-cell receptors (TCRs) on the surface of T cells. In particular, most CD1d-presented antigens are recognized by a population of lymphocytes denominated natural killer T (NKT) cells, characterized by a strong immunomodulatory potential. Among NKT cells, two major subsets (type I and type II NKT cells) have been described, based on their TCR repertoire and antigen specificity. Here we review recent structural and biochemical studies that have shed light on the molecular details of CD1d-mediated antigen recognition by type I and II NKT cells, which are in many aspects distinct from what has been observed for peptide major histocompatibility complex-reactive TCRs.
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MESH Headings
- Animals
- Antigen-Presenting Cells/cytology
- Antigen-Presenting Cells/immunology
- Antigen-Presenting Cells/metabolism
- Antigens/chemistry
- Antigens/immunology
- Antigens/metabolism
- Antigens, CD1d/chemistry
- Antigens, CD1d/immunology
- Antigens, CD1d/metabolism
- Binding Sites
- Epitopes
- Humans
- Killer Cells, Natural/cytology
- Killer Cells, Natural/immunology
- Killer Cells, Natural/metabolism
- Lipids/chemistry
- Lipids/immunology
- Mice
- Models, Molecular
- Protein Binding
- Protein Conformation
- Protein Multimerization
- Receptors, Antigen, T-Cell/chemistry
- Receptors, Antigen, T-Cell/immunology
- Receptors, Antigen, T-Cell/metabolism
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Affiliation(s)
- Enrico Girardi
- Division of Cell Biology, La Jolla Institute for Allergy and Immunology, CA, USA
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Mycoketide: a CD1c-presented antigen with important implications in mycobacterial infection. Clin Dev Immunol 2012; 2012:981821. [PMID: 22536277 PMCID: PMC3318773 DOI: 10.1155/2012/981821] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Accepted: 01/24/2012] [Indexed: 11/18/2022]
Abstract
Mycobacterium tuberculosis and related mycobacteria species are unique in that the acid-fast bacilli possess a highly lipid-rich cell wall that not simply confers resistance to treatment with acid alcohol, but also controls their survival and virulence. It has recently been established that a fraction of the cell wall lipid components of mycobacteria can function as antigens targeted by the acquired immunity of the host. Human group 1 CD1 molecules (CD1a, CD1b, and CD1c) bind a pool of lipid antigens expressed by mycobacteria and present them to specific T cells, thereby mediating an effective pathway for host defense against tuberculosis. The contrasting and mutually complementary functions of CD1a and CD1b molecules in terms of the repertoire of antigens they bind have been well appreciated, but it remains to be established how CD1c may play a unique role. Nevertheless, recent advances in our understanding of the CD1c structure as well as the biosynthetic pathway of a CD1c-presented antigen, mannose-1, β-phosphomycoketide, expressed by pathogenic mycobacteria now unravel a new aspect of the group 1 CD1 biology that has not been appreciated in previous studies of CD1a and CD1b molecules.
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Huang S, Cheng TY, Young DC, Layre E, Madigan CA, Shires J, Cerundolo V, Altman JD, Moody DB. Discovery of deoxyceramides and diacylglycerols as CD1b scaffold lipids among diverse groove-blocking lipids of the human CD1 system. Proc Natl Acad Sci U S A 2011; 108:19335-40. [PMID: 22087000 PMCID: PMC3228429 DOI: 10.1073/pnas.1112969108] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Unlike the dominant role of one class II invariant chain peptide (CLIP) in blocking MHC class II, comparative lipidomics analysis shows that human cluster of differentiation (CD) proteins CD1a, CD1b, CD1c, and CD1d bind lipids corresponding to hundreds of diverse accurate mass retention time values. Although most ions were observed in association with several CD1 proteins, ligands binding selectively to one CD1 isoform allowed the study of how differing antigen-binding grooves influence lipid capture. Although the CD1b groove is distinguished by its unusually large volume (2,200 Å(3)) and the T' tunnel, the average mass of compounds eluted from CD1b was similar to that of lipids from CD1 proteins with smaller grooves. Elution of small ligands from the large CD1b groove might be explained if two small lipids bind simultaneously in the groove. Crystal structures indicate that all CD1 proteins can capture one antigen with its hydrophilic head group exposed for T-cell recognition, but CD1b structures show scaffold lipids seated below the antigen. We found that ligands selectively associated with CD1b lacked the hydrophilic head group that is generally needed for antigen recognition but interferes with scaffold function. Furthermore, we identified the scaffolds as deoxyceramides and diacylglycerols and directly demonstrate a function in augmenting presentation of a small glycolipid antigen to T cells. Thus, unlike MHC class II, CD1 proteins capture highly diverse ligands in the secretory pathway. CD1b has a mechanism for presenting either two small or one large lipid, allowing presentation of antigens with an unusually broad range of chain lengths.
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Affiliation(s)
- Shouxiong Huang
- Department of Medicine, Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115
| | - Tan-Yun Cheng
- Department of Medicine, Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115
| | - David C. Young
- Department of Medicine, Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115
| | - Emilie Layre
- Department of Medicine, Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115
| | - Cressida A. Madigan
- Department of Medicine, Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115
| | - John Shires
- Emory Vaccine Center, Emory School of Medicine, Atlanta, GA 30322; and
| | - Vincenzo Cerundolo
- Medical Research Council Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, United Kingdom
| | - John D. Altman
- Emory Vaccine Center, Emory School of Medicine, Atlanta, GA 30322; and
| | - D. Branch Moody
- Department of Medicine, Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115
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