101
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Florence WC, Xia C, Gordy LE, Chen W, Zhang Y, Scott-Browne J, Kinjo Y, Yu KOA, Keshipeddy S, Pellicci DG, Patel O, Kjer-Nielsen L, McCluskey J, Godfrey DI, Rossjohn J, Richardson SK, Porcelli SA, Howell AR, Hayakawa K, Gapin L, Zajonc DM, Wang PG, Joyce S. Adaptability of the semi-invariant natural killer T-cell receptor towards structurally diverse CD1d-restricted ligands. EMBO J 2009; 28:3579-90. [PMID: 19816402 DOI: 10.1038/emboj.2009.286] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2009] [Accepted: 09/03/2009] [Indexed: 11/09/2022] Open
Abstract
The semi-invariant natural killer (NK) T-cell receptor (NKTcr) recognises structurally diverse glycolipid antigens presented by the monomorphic CD1d molecule. While the alpha-chain of the NKTcr is invariant, the beta-chain is more diverse, but how this diversity enables the NKTcr to recognise diverse antigens, such as an alpha-linked monosaccharide (alpha-galactosylceramide and alpha-galactosyldiacylglycerol) and the beta-linked trisaccharide (isoglobotriaosylceramide), is unclear. We demonstrate here that NKTcrs, which varied in their beta-chain usage, recognised diverse glycolipid antigens with a similar binding mode on CD1d. Nevertheless, the NKTcrs recognised distinct epitopic sites within these antigens, including alpha-galactosylceramide, the structurally similar alpha-galactosyldiacylglycerol and the very distinct isoglobotriaosylceramide. We also show that the relative roles of the CDR loops within the NKTcr beta-chain varied as a function of the antigen. Thus, while NKTcrs characteristically use a conserved docking mode, the NKTcr beta-chain allows these cells to recognise unique aspects of structurally diverse CD1d-restricted ligands.
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Affiliation(s)
- William C Florence
- Department of Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN, USA
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102
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Li Y, Thapa P, Hawke D, Kondo Y, Furukawa K, Furukawa K, Hsu FF, Adlercreutz D, Weadge J, Palcic MM, Wang PG, Levery SB, Zhou D. Immunologic glycosphingolipidomics and NKT cell development in mouse thymus. J Proteome Res 2009; 8:2740-51. [PMID: 19284783 DOI: 10.1021/pr801040h] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Invariant NKT cells are a hybrid cell type of Natural Killer cells and T cells, whose development is dependent on thymic positive selection mediated by double positive thymocytes through their recognition of natural ligands presented by CD1d, a nonpolymorphic, non-MHC, MHC-like antigen presenting molecule. Genetic evidence suggested that beta-glucosylceramide derived glycosphingolipids (GSLs) are natural ligands for NKT cells. N-butyldeoxygalactonojirimycin (NB-DGJ), a drug that specifically inhibits the glucosylceramide synthase, inhibits the endogenous ligands for NKT cells. Furthermore, we and others have found a beta-linked glycosphingolipid, isoglobotriaosylceramide (iGb3), is a stimulatory NKT ligand. The iGb3 synthase knockout mice have a normal NKT development and function, indicating that other ligands exist and remain to be identified. In this study, we have performed a glycosphingolipidomics study of mouse thymus, and studied mice mutants which are deficient in beta-hexosaminidase b or alpha-galactosidase A, two glycosidases that are up- and downstream agents of iGb3 turnover, respectively. Our mass spectrometry methods generated a first database for glycosphingolipids expressed in mouse thymus, which are specifically regulated by rate-limiting glycosidases. Among the identified thymic glycosphingolipids, only iGb3 is a stimulatory ligand for NKT cells, suggesting that large-scale fractionation, enrichment and characterization of minor species of glycosphingolipids are necessary for identifying additional ligands for NKT cells. Our results also provide early insights into cellular lipidomics studies, with a specific focus on the important immunological functions of glycosphingolipids.
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Affiliation(s)
- Yunsen Li
- Department of Melanoma Medical Oncology, Mass Spectrometry Core Facility, The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77054, USA
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103
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Schiefner A, Fujio M, Wu D, Wong CH, Wilson IA. Structural evaluation of potent NKT cell agonists: implications for design of novel stimulatory ligands. J Mol Biol 2009; 394:71-82. [PMID: 19732779 DOI: 10.1016/j.jmb.2009.08.061] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2009] [Revised: 08/25/2009] [Accepted: 08/26/2009] [Indexed: 11/15/2022]
Abstract
Natural killer T (NKT) cells are a subset of T cells that are activated by CD1d-glycolipid complexes through a semi-invariant alphabeta T cell receptor (NKT TCR). Upon activation, NKT cells secrete regulatory cytokines that are implicated in T helper cell responses. alpha-Galactosylceramide (alpha-GalCer) is a potent NKT cell agonist when presented by CD1d. Phenyl ring substitutions of the alpha-GalCer fatty acid moiety were recently found to be superior in eliciting regulatory cytokines. Crystal structures of four new mouse CD1d-lipid complexes (five structures), a new PBS-25 complex, and CD1d with an endogenous ligand, at 1.6-1.9 A resolution, reveal that the alpha-GalCer phenyl analogues impart minor structural differences to the A'-pocket, while the sphingosine and galactose moieties, important for NKT TCR recognition, remain virtually unchanged. The observed differences in cytokine-release profiles appear to be associated with increased stability of the CD1d-glycolipid complexes rather than increased affinity for the NKT TCR. Furthermore, comparison of mouse CD1d-glycolipid complexes in different crystallographic space groups reveals considerable conformational variation, particularly above the F'-pocket, the primary site of interaction with the NKT TCR. We propose that modifications of the sphingosine moiety or other substitutions that decrease alpha-GalCer flexibility would stabilize the F'-pocket. Such compounds might then increase CD1d affinity for the NKT TCR and further enhance the stimulatory and regulatory properties of alpha-GalCer derivatives.
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Affiliation(s)
- André Schiefner
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
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104
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Abstract
A crucial role has been suggested for invariant natural killer T cells (iNKT) in regulating the development of asthma, a complex and heterogeneous disease characterized by airway inflammation and airway hyperreactivity (AHR). iNKT cells constitute a unique subset of T cells responding to endogenous and exogenous lipid antigens, rapidly secreting a large amount of cytokines, which amplify both innate and adaptive immunity. Herein, we review recent studies showing a requirement for iNKT cells in various models of asthma in mice and monkeys as well as studies in human patients. Surprisingly, in several different murine models of asthma, distinct subsets of iNKT cells were required, suggesting that iNKT cells serve as a common critical pathogenic element for many different forms of asthma. The importance of iNKT cells in both allergic and non-allergic forms of asthma, which are independent of adaptive immunity and associated with airway neutrophils, may explain situations previously found to be incompatible with the Th2 paradigm of asthma.
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105
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Pellicci DG, Patel O, Kjer-Nielsen L, Pang SS, Sullivan LC, Kyparissoudis K, Brooks AG, Reid HH, Gras S, Lucet IS, Koh R, Smyth MJ, Mallevaey T, Matsuda JL, Gapin L, McCluskey J, Godfrey DI, Rossjohn J. Differential recognition of CD1d-alpha-galactosyl ceramide by the V beta 8.2 and V beta 7 semi-invariant NKT T cell receptors. Immunity 2009; 31:47-59. [PMID: 19592275 DOI: 10.1016/j.immuni.2009.04.018] [Citation(s) in RCA: 187] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2008] [Revised: 04/01/2009] [Accepted: 04/24/2009] [Indexed: 11/26/2022]
Abstract
The semi-invariant natural killer T cell receptor (NKT TCR) recognizes CD1d-lipid antigens. Although the TCR alpha chain is typically invariant, the beta chain expression is more diverse, where three V beta chains are commonly expressed in mice. We report the structures of V alpha 14-V beta 8.2 and V alpha 14-V beta 7 NKT TCRs in complex with CD1d-alpha-galactosylceramide (alpha-GalCer) and the 2.5 A structure of the human NKT TCR-CD1d-alpha-GalCer complex. Both V beta 8.2 and V beta 7 NKT TCRs and the human NKT TCR ligated CD1d-alpha-GalCer in a similar manner, highlighting the evolutionarily conserved interaction. However, differences within the V beta domains of the V beta 8.2 and V beta 7 NKT TCR-CD1d complexes resulted in altered TCR beta-CD1d-mediated contacts and modulated recognition mediated by the invariant alpha chain. Mutagenesis studies revealed the differing contributions of V beta 8.2 and V beta 7 residues within the CDR2 beta loop in mediating contacts with CD1d. Collectively we provide a structural basis for the differential NKT TCR V beta usage in NKT cells.
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Affiliation(s)
- Daniel G Pellicci
- Department of Microbiology and Immunology, University of Melbourne, Parkville, Victoria 3010, Australia
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106
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Kasmar A, Rhijn IV, Moody DB. The evolved functions of CD1 during infection. Curr Opin Immunol 2009; 21:397-403. [PMID: 19541469 PMCID: PMC2725205 DOI: 10.1016/j.coi.2009.05.022] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2009] [Revised: 05/18/2009] [Accepted: 05/19/2009] [Indexed: 10/20/2022]
Abstract
CD1 proteins display lipid antigens to T cell receptors. Studies using CD1d tetramers and CD1d-deficient mice provide important insight into the immunological functions of invariant NK T cells (iNKT) during viral and bacterial infections. However, the mouse CD1 locus is atypical because it encodes only CD1d, whereas most mammalian species have retained many CD1 genes. Viewed from the perspective that CD1 is a diverse gene family that activates several of classes of T cells, new insights into lipid loading and infection response are emerging.
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Affiliation(s)
- Anne Kasmar
- Division of Rheumatology, Immunology and Allergy Brigham and Women's Hospital Harvard Medical School 1 Jimmy Fund Way Boston MA 02115
| | - Ildiko Van Rhijn
- Division of Infectious Diseases and Immunity, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
| | - D. Branch Moody
- Division of Rheumatology, Immunology and Allergy Brigham and Women's Hospital Harvard Medical School 1 Jimmy Fund Way Boston MA 02115
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107
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Pilones KA, Kawashima N, Yang AM, Babb JS, Formenti SC, Demaria S. Invariant natural killer T cells regulate breast cancer response to radiation and CTLA-4 blockade. Clin Cancer Res 2009; 15:597-606. [PMID: 19147765 DOI: 10.1158/1078-0432.ccr-08-1277] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
PURPOSE Immunoregulatory and suppressive mechanisms represent major obstacles to the success of immunotherapy in cancer patients. We have shown that the combination of radiotherapy to the primary tumor and CTL-associated protein 4 (CTLA-4) blockade induces antitumor immunity, inhibiting metastases and extending the survival of mice bearing the poorly immunogenic and highly metastatic 4T1 mammary carcinoma. Similarly to patients with metastatic cancer, however, mice were seldom cured. Here we tested the hypothesis that invariant natural killer T (iNKT) cells, a subset with unique regulatory functions, can regulate the response to radiotherapy and CTLA-4 blockade. EXPERIMENTAL DESIGN The growth of 4T1 primary tumors and lung metastases was compared in wild-type and iNKT cell-deficient (iNKT-/-) mice. Treatment was started on day 13 when the primary tumors were palpable. Mice received radiotherapy to the primary tumor in two doses of 12 Gy in combination or not with 9H10 monoclonal antibody against CTLA-4. Response to treatment was assessed by measuring primary tumor growth delay/regression, survival, and number of lung metastases. RESULTS The response to radiotherapy plus 9H10 was markedly enhanced in the absence of iNKT cells, with 50% of iNKT-/- versus 0% of wild-type mice showing complete tumor regression, long-term survival, and resistance to a challenge with 4T1 cells. Administration of the iNKT cell activator alpha-galactosylceramide did not enhance the response of wild-type mice to radiotherapy plus 9H10. Tumor-infiltrating iNKT cells were markedly reduced in wild-type mice treated with radiotherapy plus 9H10. CONCLUSIONS iNKT cells play a major role in regulating the response to treatment with local radiotherapy and CTLA-4 blockade.
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Affiliation(s)
- Karsten A Pilones
- Department of Pathology, New York University School of Medicine and NYU Langone Medical Center, New York, New York 10016, USA
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108
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Mallevaey T, Scott-Browne JP, Matsuda JL, Young MH, Pellicci DG, Patel O, Thakur M, Kjer-Nielsen L, Richardson SK, Cerundolo V, Howell AR, McCluskey J, Godfrey DI, Rossjohn J, Marrack P, Gapin L. T cell receptor CDR2 beta and CDR3 beta loops collaborate functionally to shape the iNKT cell repertoire. Immunity 2009; 31:60-71. [PMID: 19592274 PMCID: PMC2965025 DOI: 10.1016/j.immuni.2009.05.010] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2008] [Revised: 04/21/2009] [Accepted: 05/22/2009] [Indexed: 12/12/2022]
Abstract
Mouse type I natural killer T cell receptors (iNKT TCRs) use a single V alpha 14-J alpha 18 sequence and V beta s that are almost always V beta 8.2, V beta 7, or V beta 2, although the basis of this differential usage is unclear. We showed that the V beta bias occurred as a consequence of the CDR2 beta loops determining the affinity of the iNKT TCR for CD1d-glycolipids, thus controlling positive selection. Within a conserved iNKT-TCR-CD1d docking framework, these inherent V beta-CD1d affinities are further modulated by the hypervariable CDR3 beta loop, thereby defining a functional interplay between the two iNKT TCR CDR beta loops. These V beta biases revealed a broadly hierarchical response in which V beta 8.2 > V beta 7 > V beta 2 in the recognition of diverse CD1d ligands. This restriction of the iNKT TCR repertoire during thymic selection paradoxically ensures that each peripheral iNKT cell recognizes a similar spectrum of antigens.
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MESH Headings
- Animals
- Antigens, CD1d/immunology
- Antigens, CD1d/metabolism
- Mice
- Mice, Inbred C57BL
- Natural Killer T-Cells/immunology
- Natural Killer T-Cells/metabolism
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Antigen, T-Cell, alpha-beta/immunology
- Receptors, Antigen, T-Cell, alpha-beta/metabolism
- Thymus Gland/immunology
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Affiliation(s)
- Thierry Mallevaey
- Department of Immunology, University of Colorado Denver and National Jewish Health, Denver, CO 80206, USA
| | - James P. Scott-Browne
- Department of Immunology, University of Colorado Denver and National Jewish Health, Denver, CO 80206, USA
| | - Jennifer L. Matsuda
- Department of Immunology, University of Colorado Denver and National Jewish Health, Denver, CO 80206, USA
| | - Mary H. Young
- Department of Immunology, University of Colorado Denver and National Jewish Health, Denver, CO 80206, USA
| | - Daniel G. Pellicci
- Department of Microbiology & Immunology, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Onisha Patel
- The Protein Crystallography Unit, ARC Centre of Excellence in Structural and Functional Microbial Genomics, Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Meena Thakur
- Department of Chemistry, University of Connecticut, Storrs, CT, USA
| | - Lars Kjer-Nielsen
- Department of Microbiology & Immunology, University of Melbourne, Parkville, Victoria 3010, Australia
| | | | - Vincenzo Cerundolo
- Tumour Immunology Group, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Oxford, United Kingdom
| | - Amy R. Howell
- Department of Chemistry, University of Connecticut, Storrs, CT, USA
| | - James McCluskey
- Department of Microbiology & Immunology, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Dale I. Godfrey
- Department of Microbiology & Immunology, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Jamie Rossjohn
- The Protein Crystallography Unit, ARC Centre of Excellence in Structural and Functional Microbial Genomics, Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Philippa Marrack
- Department of Immunology, University of Colorado Denver and National Jewish Health, Denver, CO 80206, USA
- Howard Hughes Medical Institute, University of Colorado Denver school of Medicine, Denver, CO 80220, USA
- Department of Medicine, University of Colorado Denver school of Medicine, Denver, CO 80220, USA
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver school of Medicine, Denver, CO 80220, USA
| | - Laurent Gapin
- Department of Immunology, University of Colorado Denver and National Jewish Health, Denver, CO 80206, USA
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109
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Zajonc DM, Kronenberg M. Carbohydrate specificity of the recognition of diverse glycolipids by natural killer T cells. Immunol Rev 2009; 230:188-200. [DOI: 10.1111/j.1600-065x.2009.00802.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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110
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Raju R, Castillo BF, Richardson SK, Thakur M, Severins R, Kronenberg M, Howell AR. Synthesis and evaluation of 3''- and 4''-deoxy and -fluoro analogs of the immunostimulatory glycolipid, KRN7000. Bioorg Med Chem Lett 2009; 19:4122-5. [PMID: 19535248 DOI: 10.1016/j.bmcl.2009.06.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Revised: 05/28/2009] [Accepted: 06/01/2009] [Indexed: 12/25/2022]
Abstract
Four 3''- and 4''-deoxy and -fluorogalactosyl ceramides were synthesized, and their ability to stimulate iNKT cells, based on levels of IL-2 production, was assessed in three NKT cell receptor hybridomas. In two of the hybridomas, 1.2 and 2H4, all of the analogs were immunostimulatory, while in the 1.4 hybridoma only the 4''-fluoro analog led to the production of significant levels of IL-2.
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Affiliation(s)
- Ravinder Raju
- Department of Chemistry, University of Connecticut, Storrs, CT 06269-3060, United States
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111
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Abstract
Mucosal-associated invariant T cells are newly identified subpopulation of T cells. A new study highlights their developmental pathway and functional features that allow these cells to assume a unique position in the family of unconventional T cells.
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112
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Scott-Browne JP, White J, Kappler JW, Gapin L, Marrack P. Germline-encoded amino acids in the alphabeta T-cell receptor control thymic selection. Nature 2009; 458:1043-6. [PMID: 19262510 PMCID: PMC2679808 DOI: 10.1038/nature07812] [Citation(s) in RCA: 131] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2008] [Accepted: 01/20/2009] [Indexed: 11/15/2022]
Abstract
An alphabeta T-cell response depends on the recognition of antigen plus major histocompatibility complex (MHC) proteins by its antigen receptor (TCR). The ability of peripheral alphabeta T cells to recognize MHC is at least partly determined by MHC-dependent thymic selection, by which an immature T cell survives only if its TCR can recognize self MHC. This process may allow MHC-reactive TCRs to be selected from a repertoire with completely random and unbiased specificities. However, analysis of thymocytes before positive selection indicated that TCR proteins might have a predetermined ability to bind MHC. Here we show that specific germline-encoded amino acids in the TCR promote 'generic' MHC recognition and control thymic selection. In mice expressing single, rearranged TCR beta-chains, individual mutation of amino acids in the complementarity-determining region (CDR) 2beta to Ala reduced development of the entire TCR repertoire. Altogether, these results show that thymic selection is controlled by germline-encoded MHC contact points in the alphabeta TCR and indicate that the diversity of the peripheral T-cell repertoire is enhanced by this 'built-in' specificity.
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MESH Headings
- Amino Acids/genetics
- Amino Acids/metabolism
- Animals
- Bone Marrow/immunology
- Bone Marrow/metabolism
- Cell Line
- Chimera/immunology
- Chimera/metabolism
- Complementarity Determining Regions/chemistry
- Complementarity Determining Regions/genetics
- Complementarity Determining Regions/immunology
- Germ Cells/metabolism
- Hybridomas/immunology
- Major Histocompatibility Complex/immunology
- Mice
- Receptors, Antigen, T-Cell, alpha-beta/chemistry
- Receptors, Antigen, T-Cell, alpha-beta/deficiency
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Antigen, T-Cell, alpha-beta/immunology
- Thymus Gland/cytology
- Thymus Gland/immunology
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Affiliation(s)
- James P Scott-Browne
- Integrated Department of Immunology, National Jewish Health and University of Colorado Denver, Denver, Colorado 80206, USA.
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113
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Looringh van Beeck FA, Reinink P, Hermsen R, Zajonc DM, Laven MJ, Fun A, Troskie M, Schoemaker NJ, Morar D, Lenstra JA, Vervelde L, Rutten VP, van Eden W, Van Rhijn I. Functional CD1d and/or NKT cell invariant chain transcript in horse, pig, African elephant and guinea pig, but not in ruminants. Mol Immunol 2009; 46:1424-31. [PMID: 19185921 PMCID: PMC2669151 DOI: 10.1016/j.molimm.2008.12.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2008] [Accepted: 12/16/2008] [Indexed: 10/28/2022]
Abstract
CD1d-restricted invariant natural killer T cells (NKT cells) have been well characterized in humans and mice, but it is unknown whether they are present in other species. Here we describe the invariant TCR alpha chain and the full length CD1d transcript of pig and horse. Molecular modeling predicts that porcine (po) invariant TCR alpha chain/poCD1d/alpha-GalCer and equine (eq) invariant TCR alpha chain/eqCD1d/alpha-GalCer form complexes that are highly homologous to the human complex. Since a prerequisite for the presence of NKT cells is the expression of CD1d protein, we performed searches for CD1D genes and CD1d transcripts in multiple species. Previously, cattle and guinea pig have been suggested to lack CD1D genes. The CD1D genes of European taurine cattle (Bos taurus) are known to be pseudogenes because of disrupting mutations in the start codon and in the donor splice site of the first intron. Here we show that the same mutations are found in six other ruminants: African buffalo, sheep, bushbuck, bongo, N'Dama cattle, and roe deer. In contrast, intact CD1d transcripts were found in guinea pig, African elephant, horse, rabbit, and pig. Despite the discovery of a highly homologous NKT/CD1d system in pig and horse, our data suggest that functional CD1D and CD1d-restricted NKT cells are not universally present in mammals.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antigens, CD1d/genetics
- Antigens, CD1d/metabolism
- Antigens, Differentiation, B-Lymphocyte/genetics
- Antigens, Differentiation, B-Lymphocyte/metabolism
- Cats
- Cattle
- Dogs
- Elephants/genetics
- Elephants/immunology
- Elephants/metabolism
- Guinea Pigs
- Histocompatibility Antigens Class II/genetics
- Histocompatibility Antigens Class II/metabolism
- Horses/genetics
- Horses/immunology
- Horses/metabolism
- Humans
- Models, Molecular
- Molecular Sequence Data
- Natural Killer T-Cells/metabolism
- RNA, Messenger/analysis
- RNA, Messenger/metabolism
- Ruminants/genetics
- Ruminants/immunology
- Ruminants/metabolism
- Sequence Homology, Amino Acid
- Sheep
- Swine/genetics
- Swine/immunology
- Swine/metabolism
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Affiliation(s)
- Frank A. Looringh van Beeck
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, University Utrecht, Utrecht, The Netherlands
| | - Peter Reinink
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, University Utrecht, Utrecht, The Netherlands
| | - Roel Hermsen
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, University Utrecht, Utrecht, The Netherlands
| | - Dirk M. Zajonc
- Division of Cell Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA, USA
| | - Marielle J. Laven
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, University Utrecht, Utrecht, The Netherlands
| | - Axel Fun
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, University Utrecht, Utrecht, The Netherlands
| | - Milana Troskie
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, South Africa
| | - Nico J. Schoemaker
- Department of Clinical Sciences of Companion Animals, University Utrecht, Utrecht, The Netherlands
| | - Darshana Morar
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, South Africa
| | | | - Lonneke Vervelde
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, University Utrecht, Utrecht, The Netherlands
| | - Victor P.M.G. Rutten
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, University Utrecht, Utrecht, The Netherlands
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, South Africa
| | - Willem van Eden
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, University Utrecht, Utrecht, The Netherlands
| | - Ildiko Van Rhijn
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, University Utrecht, Utrecht, The Netherlands
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114
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Garcia KC, Adams JJ, Feng D, Ely LK. The molecular basis of TCR germline bias for MHC is surprisingly simple. Nat Immunol 2009; 10:143-7. [PMID: 19148199 PMCID: PMC3982143 DOI: 10.1038/ni.f.219] [Citation(s) in RCA: 186] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The elusive etiology of germline bias of the T cell receptor (TCR) for major histocompatibility complex (MHC) has been clarified by recent 'proof-of-concept' structural results demonstrating the conservation of specific TCR-MHC interfacial contacts in complexes bearing common variable segments and MHC allotypes. We suggest that each TCR variable-region gene product engages each type of MHC through a 'menu' of structurally coded recognition motifs that have arisen through coevolution. The requirement for MHC-restricted T cell recognition during thymic selection and peripheral surveillance has necessitated the existence of such a coded recognition system. Given these findings, a reconsideration of the TCR-peptide-MHC structural database shows that not only have the answers been there all along but also they were predictable by the first principles of physical chemistry.
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Affiliation(s)
- K Christopher Garcia
- Department of Molecular & Cellular Physiology, Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California 94305, USA.
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115
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Kinjo Y, Kronenberg M. Detection of microbes by natural killer T cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2009; 633:17-26. [PMID: 19209678 DOI: 10.1007/978-0-387-79311-5_3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Yuki Kinjo
- La Jolla Institute for Allergy and Immunology, CA 92037, USA
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116
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Cerundolo V, Silk JD, Masri SH, Salio M. Harnessing invariant NKT cells in vaccination strategies. Nat Rev Immunol 2009; 9:28-38. [DOI: 10.1038/nri2451] [Citation(s) in RCA: 272] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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117
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Silk JD, Salio M, Brown J, Jones EY, Cerundolo V. Structural and functional aspects of lipid binding by CD1 molecules. Annu Rev Cell Dev Biol 2008; 24:369-95. [PMID: 18593354 DOI: 10.1146/annurev.cellbio.24.110707.175359] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Over the past ten 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 molecules the CD1 proteins. We describe the events that have led to the discovery of the role of CD1 molecules, their pattern of intracellular trafficking, and their ability to sample different intracellular compartments for self- and foreign lipids. Structural and functional aspects of lipid presentation by CD1 molecules are presented in the context of the function of CD1-restricted T cells in antimicrobial responses, antitumor immunity, and the regulation of the tolerance and autoimmunity immunoregulatory axis. Particular emphasis is on invariant NKT (iNKT) cells and their ability to modulate innate and adaptive immune responses.
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Affiliation(s)
- Jonathan D Silk
- Tumour Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, United Kingdom
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118
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Christiansen D, Milland J, Mouhtouris E, Vaughan H, Pellicci DG, McConville MJ, Godfrey DI, Sandrin MS. Humans lack iGb3 due to the absence of functional iGb3-synthase: implications for NKT cell development and transplantation. PLoS Biol 2008; 6:e172. [PMID: 18630988 PMCID: PMC2459210 DOI: 10.1371/journal.pbio.0060172] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2007] [Accepted: 06/06/2008] [Indexed: 11/18/2022] Open
Abstract
The glycosphingolipid isoglobotrihexosylceramide, or isogloboside 3 (iGb3), is believed to be critical for natural killer T (NKT) cell development and self-recognition in mice and humans. Furthermore, iGb3 may represent an important obstacle in xenotransplantation, in which this lipid represents the only other form of the major xenoepitope Galα(1,3)Gal. The role of iGb3 in NKT cell development is controversial, particularly with one study that suggested that NKT cell development is normal in mice that were rendered deficient for the enzyme iGb3 synthase (iGb3S). We demonstrate that spliced iGb3S mRNA was not detected after extensive analysis of human tissues, and furthermore, the iGb3S gene contains several mutations that render this product nonfunctional. We directly tested the potential functional activity of human iGb3S by expressing chimeric molecules containing the catalytic domain of human iGb3S. These hybrid molecules were unable to synthesize iGb3, due to at least one amino acid substitution. We also demonstrate that purified normal human anti-Gal immunoglobulin G can bind iGb3 lipid and mediate complement lysis of transfected human cells expressing iGb3. Collectively, our data suggest that iGb3S is not expressed in humans, and even if it were expressed, this enzyme would be inactive. Consequently, iGb3 is unlikely to represent a primary natural ligand for NKT cells in humans. Furthermore, the absence of iGb3 in humans implies that it is another source of foreign Galα(1,3)Gal xenoantigen, with obvious significance in the field of xenotransplantation. Identification of endogenous antigens that regulate natural killer T (NKT) cell development and function is a major goal in immunology. Originally the glycosphingolipid, iGb3, was suggested to be the main endogenous ligand in both mice and humans. However, recent studies have challenged this hypothesis. From a xenotransplantation (animal to human transplants) perspective, iGb3 expression is also important as it represents another form of the major xenoantigen Galα(1,3)Gal. In this study, we assessed whether humans expressed a functional iGb3 synthase (iGb3S), the enzyme responsible for lipid synthesis. We showed that spliced iGb3S mRNA was not detected in any human tissue analysed. Furthermore, chimeric molecules composed of the catalytic domain of human iGb3S were unable to synthesize iGb3 lipid, due to at least one amino acid substitution. We also demonstrated that purified human anti-Gal antibodies bound iGb3 lipid and mediated destruction of cells transfected to express iGb3. A nonfunctional iGb3S in humans has two major consequences: (1) iGb3 is unlikely to be a natural human NKT ligand and (2) natural human anti-Gal antibodies in human serum could react with iGb3 on the surface of organs from pigs, marking these tissues for immunological destruction. Controversy surrounds the glycolipid iGb3. Our data show that humans do not express this lipid. This has important implications in natural killer T cell development, self-recognition, and transplantation.
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Affiliation(s)
- Dale Christiansen
- Department of Surgery, The University of Melbourne, Austin Health/Northern Health, Heidelberg, Victoria, Australia
| | - Julie Milland
- Department of Surgery, The University of Melbourne, Austin Health/Northern Health, Heidelberg, Victoria, Australia
| | - Effie Mouhtouris
- Department of Surgery, The University of Melbourne, Austin Health/Northern Health, Heidelberg, Victoria, Australia
| | - Hilary Vaughan
- Department of Surgery, The University of Melbourne, Austin Health/Northern Health, Heidelberg, Victoria, Australia
| | - Daniel G Pellicci
- Department of Microbiology and Immunology, The University of Melbourne, Parkville, Victoria, Australia
| | - Malcolm J McConville
- Department of Biochemistry and Molecular Biology, The University of Melbourne, Bio21 Molecular Science and Biotechnology Institute, Melbourne, Victoria, Australia
| | - Dale I Godfrey
- Department of Microbiology and Immunology, The University of Melbourne, Parkville, Victoria, Australia
| | - Mauro S Sandrin
- Department of Surgery, The University of Melbourne, Austin Health/Northern Health, Heidelberg, Victoria, Australia
- * To whom correspondence should be addressed. E-mail:
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119
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T-cells behaving badly: structural insights into alloreactivity and autoimmunity. Curr Opin Immunol 2008; 20:575-80. [DOI: 10.1016/j.coi.2008.07.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2008] [Accepted: 07/08/2008] [Indexed: 11/22/2022]
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120
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Abstract
The CD1 family of antigen-presenting molecules consists of five members, CD1a to e. Of these molecules CD1d has been the subject of much interest over the past 10 years following the discovery that this molecule presents antigens to a group of T cells known as invariant natural killer T cells (iNKT). iNKT cells carry an invariant T cell receptor which contains homologous gene segments in mouse and man. iNKT cells are positively selected in the thymus in the same manner as major histocompatibility complex restricted T cells, except iNKT cells require CD1d to be presented by thymocytes rather than epithelial cells. Once in peripheral organs, iNKT cells appear to play multiple roles in host defence against pathogens and cancer. If the numbers of iNKT cells are not correctly regulated it can result in autoimmune disorders, such as diabetes. The ligands for iNKT cells have been the subject of much research but identifying physiologically relevant candidate ligands for positive selection or activation has proved technically very challenging. This is largely due to the fact that the ligands for iNKT cells are lipids. The lipid ligands for thymic selection and some of those involved in peripheral activation are self-derived. Glycosphingolipids are suggested to be the class of lipid for iNKT cell thymic development. For peripheral activation it appears multiple classes of self-derived lipids may play a role, in addition to pathogen-derived lipids. This review will cover essential background to iNKT cell and CD1d biology with emphasis on the candidate iNKT cell ligands proposed to date.
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Affiliation(s)
- Anneliese O Speak
- Department of Pharmacology, University of Oxford, and Weatherall Institute of Molecular Medicine, Tumour Immunology Group, John Radcliffe Hospital, Oxford, UK.
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121
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CD1d-restricted glycolipid antigens: presentation principles, recognition logic and functional consequences. Expert Rev Mol Med 2008; 10:e20. [PMID: 18601810 DOI: 10.1017/s1462399408000732] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Invariant natural killer T (iNKT) cells are innate lymphocytes whose functions are regulated by self and foreign glycolipid antigens presented by the antigen-presenting molecule CD1d. Activation of iNKT cells in vivo results in rapid release of copious amounts of effector cytokines and chemokines with which they regulate innate and adaptive immune responses to pathogens, certain types of cancers and self-antigens. The nature of CD1d-restricted antigens, the manner in which they are recognised and the unique effector functions of iNKT cells suggest an innate immunoregulatory role for this subset of T cells. Their ability to respond fast and our ability to steer iNKT cell cytokine response to altered lipid antigens make them an important target for vaccine design and immunotherapies against autoimmune diseases. This review summarises our current understanding of CD1d-restricted antigen presentation, the recognition of such antigens by an invariant T-cell receptor on iNKT cells, and the functional consequences of these interactions.
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122
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Silk JD, Salio M, Reddy BG, Shepherd D, Gileadi U, Brown J, Masri SH, Polzella P, Ritter G, Besra GS, Jones EY, Schmidt RR, Cerundolo V. Cutting edge: nonglycosidic CD1d lipid ligands activate human and murine invariant NKT cells. THE JOURNAL OF IMMUNOLOGY 2008; 180:6452-6. [PMID: 18453560 DOI: 10.4049/jimmunol.180.10.6452] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Invariant NKT cells (iNKT cells) recognize CD1d/glycolipid complexes. We demonstrate that the nonglycosidic compound threitolceramide efficiently activates iNKT cells, resulting in dendritic cell (DC) maturation and the priming of Ag-specific T and B cells. Threitolceramide-pulsed DCs are more resistant to iNKT cell-dependent lysis than alpha-galactosylceramide-pulsed DCs due to the weaker affinity of the human iNKT TCR for CD1d/ threitolceramide than CD1d/alpha-galactosylceramide complexes. iNKT cells stimulated with threitolceramide also recover more quickly from activation-induced anergy. Kinetic and functional experiments showed that shortening or lengthening the threitol moiety by one hydroxymethylene group modulates ligand recognition, as human and murine iNKT cells recognize glycerolceramide and arabinitolceramide differentially. Our data broaden the range of potential iNKT cell agonists. The ability of these compounds to assist the priming of Ag-specific immune responses while minimizing iNKT cell-dependent DC lysis makes them attractive adjuvants for vaccination strategies.
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Affiliation(s)
- Jonathan D Silk
- Tumour Immunology Group, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Oxford, UK
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123
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Marrack P, Scott-Browne JP, Dai S, Gapin L, Kappler JW. Evolutionarily conserved amino acids that control TCR-MHC interaction. Annu Rev Immunol 2008; 26:171-203. [PMID: 18304006 DOI: 10.1146/annurev.immunol.26.021607.090421] [Citation(s) in RCA: 206] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The rules for the conserved reaction of alphabeta T cell receptors (TCRs) with major histocompatibility complex (MHC) proteins plus peptides are poorly understood, probably because thymocytes bearing TCRs with the strongest MHC reactivity are lost by negative selection. Thus, only TCRs with an attenuated ability to react with MHC appear on mature T cells. Also, the interaction sites between TCRs and MHC may be inherently flexible and hence difficult to spot. We reevaluated contacts between TCRs and MHC in the solved structures of their complexes with these points in mind. Relatively conserved amino acids in the TCR complementarity-determining regions (CDR) 1 and CDR2 are often used to bind exposed areas of the MHC alpha-helices. These areas are exposed because of small amino acids that allow somewhat flexible binding of the TCRs. The TCR amino acids involved are specific to families of variable (V) regions and to some extent different rules may govern the recognition of MHCI versus MHCII.
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Affiliation(s)
- Philippa Marrack
- Howard Hughes Medical Institute, University of Colorado Denver Health Science Center, Denver, Colorado 80206, USA.
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124
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Matsuda JL, Mallevaey T, Scott-Browne J, Gapin L. CD1d-restricted iNKT cells, the 'Swiss-Army knife' of the immune system. Curr Opin Immunol 2008; 20:358-68. [PMID: 18501573 DOI: 10.1016/j.coi.2008.03.018] [Citation(s) in RCA: 310] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2008] [Revised: 03/27/2008] [Accepted: 03/31/2008] [Indexed: 10/22/2022]
Abstract
Natural Killer T cells are a distinct lymphocyte lineage that regulates a broad range of immune responses. NKT cells recognize glycolipids presented by the non-classical MHC molecule CD1d. Structural insight into the TCR/glycolipid/CD1d tri-complex has revealed an unusual and unexpected mode of recognition. Recent studies have also identified some of the signaling events during NKT cell development that give NKT cells their innate phenotype. Pathogen-derived glycolipid antigens continue to be found, and new mechanisms of NKT cell activation have been described. Finally, NKT cells have been shown to be remarkably versatile in function during various immune responses. Whether these extensive functional capacities can be attributed to a single population sensitive to environmental cues or if functionally distinct NKT cell subpopulations exist remains unresolved.
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Affiliation(s)
- Jennifer L Matsuda
- Integrated Department of Immunology, University of Colorado Health Sciences Center, National Jewish Medical and Research Center, Denver, CO 80206, USA
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125
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Zajonc DM, Savage PB, Bendelac A, Wilson IA, Teyton L. Crystal structures of mouse CD1d-iGb3 complex and its cognate Valpha14 T cell receptor suggest a model for dual recognition of foreign and self glycolipids. J Mol Biol 2008; 377:1104-16. [PMID: 18295796 PMCID: PMC2579742 DOI: 10.1016/j.jmb.2008.01.061] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2007] [Revised: 01/10/2008] [Accepted: 01/14/2008] [Indexed: 10/22/2022]
Abstract
The semi-invariant Valpha14Jalpha18 T cell receptor (TCR) is expressed by regulatory NKT cells and has the unique ability to recognize chemically diverse ligands presented by CD1d. The crystal structure of CD1d complexed to a natural, endogenous ligand, isoglobotrihexosylceramide (iGb3), illustrates the extent of this diversity when compared to the binding of potent, exogenous ligands, such as alpha-galactosylceramide (alpha-GalCer). A single mode of recognition for these two classes of ligands would then appear problematic for a single T cell receptor. However, the Valpha14 TCR adopts two different conformations in the crystal where, in one configuration, the presence of a larger cavity between the two CDR3 regions could accommodate iGb3 and, in the other, a smaller cavity fits alpha-GalCer more snugly. Alternatively, the extended iGb3 headgroup could be "squashed" upon docking of the TCR and accommodated between the CD1 and TCR surfaces. Thus, the same TCR may adopt alternative modes of recognition for these foreign and self-ligands for NKT cell activation.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antigens, CD1/chemistry
- Antigens, CD1/metabolism
- Autoantigens/metabolism
- Cells, Cultured
- Crystallography, X-Ray
- Globosides/chemistry
- Globosides/metabolism
- Glycolipids/metabolism
- Humans
- Killer Cells, Natural/metabolism
- Lymphocyte Activation/physiology
- Mice
- Models, Biological
- Models, Molecular
- Molecular Sequence Data
- Protein Binding
- Receptors, Antigen, T-Cell, alpha-beta/chemistry
- Sequence Homology, Amino Acid
- Trihexosylceramides/chemistry
- Trihexosylceramides/metabolism
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Affiliation(s)
- Dirk M Zajonc
- Department of Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Rd., La Jolla, CA 92037, USA
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126
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Wun KS, Borg NA, Kjer-Nielsen L, Beddoe T, Koh R, Richardson SK, Thakur M, Howell AR, Scott-Browne JP, Gapin L, Godfrey DI, McCluskey J, Rossjohn J. A minimal binding footprint on CD1d-glycolipid is a basis for selection of the unique human NKT TCR. ACTA ACUST UNITED AC 2008; 205:939-49. [PMID: 18378792 PMCID: PMC2292230 DOI: 10.1084/jem.20072141] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Although it has been established how CD1 binds a variety of lipid antigens (Ag), data are only now emerging that show how alphabeta T cell receptors (TCRs) interact with CD1-Ag. Using the structure of the human semiinvariant NKT TCR-CD1d-alpha-galactosylceramide (alpha-GalCer) complex as a guide, we undertook an alanine scanning mutagenesis approach to define the energetic basis of this interaction between the NKT TCR and CD1d. Moreover, we explored how analogues of alpha-GalCer affected this interaction. The data revealed that an identical energetic footprint underpinned the human and mouse NKT TCR-CD1d-alpha-GalCer cross-reactivity. Some, but not all, of the contact residues within the Jalpha18-encoded invariant CDR3alpha loop and Vbeta11-encoded CDR2beta loop were critical for recognizing CD1d. The residues within the Valpha24-encoded CDR1alpha and CDR3alpha loops that contacted the glycolipid Ag played a smaller energetic role compared with the NKT TCR residues that contacted CD1d. Collectively, our data reveal that the region distant to the protruding Ag and directly above the F' pocket of CD1d was the principal factor in the interaction with the NKT TCR. Accordingly, although the structural footprint at the NKT TCR-CD1d-alpha-GalCer is small, the energetic footprint is smaller still, and reveals the minimal requirements for CD1d restriction.
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Affiliation(s)
- Kwok S Wun
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria, Australia
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127
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Petrie EJ, Clements CS, Lin J, Sullivan LC, Johnson D, Huyton T, Heroux A, Hoare HL, Beddoe T, Reid HH, Wilce MCJ, Brooks AG, Rossjohn J. CD94-NKG2A recognition of human leukocyte antigen (HLA)-E bound to an HLA class I leader sequence. J Exp Med 2008; 205:725-35. [PMID: 18332182 PMCID: PMC2275392 DOI: 10.1084/jem.20072525] [Citation(s) in RCA: 159] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2007] [Accepted: 02/14/2008] [Indexed: 11/04/2022] Open
Abstract
The recognition of human leukocyte antigen (HLA)-E by the heterodimeric CD94-NKG2 natural killer (NK) receptor family is a central innate mechanism by which NK cells monitor the expression of other HLA molecules, yet the structural basis of this highly specific interaction is unclear. Here, we describe the crystal structure of CD94-NKG2A in complex with HLA-E bound to a peptide derived from the leader sequence of HLA-G. The CD94 subunit dominated the interaction with HLA-E, whereas the NKG2A subunit was more peripheral to the interface. Moreover, the invariant CD94 subunit dominated the peptide-mediated contacts, albeit with poor surface and chemical complementarity. This unusual binding mode was consistent with mutagenesis data at the CD94-NKG2A-HLA-E interface. There were few conformational changes in either CD94-NKG2A or HLA-E upon ligation, and such a "lock and key" interaction is typical of innate receptor-ligand interactions. Nevertheless, the structure also provided insight into how this interaction can be modulated by subtle changes in the peptide ligand or by the pairing of CD94 with other members of the NKG2 family. Differences in the docking strategies used by the NKG2D and CD94-NKG2A receptors provided a basis for understanding the promiscuous nature of ligand recognition by NKG2D compared with the fidelity of the CD94-NKG2 receptors.
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Affiliation(s)
- Emma J Petrie
- The Protein Crystallography Unit, ARC Centre of Excellence in Structural and Functional Microbial Genomics, Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria 3800, Australia
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128
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129
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How T cells get grip on lipid antigens. Curr Opin Immunol 2008; 20:96-104. [DOI: 10.1016/j.coi.2007.10.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2007] [Accepted: 10/31/2007] [Indexed: 11/18/2022]
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130
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Li Y, Teneberg S, Thapa P, Bendelac A, Levery SB, Zhou D. Sensitive detection of isoglobo and globo series tetraglycosylceramides in human thymus by ion trap mass spectrometry. Glycobiology 2007; 18:158-65. [PMID: 18056651 DOI: 10.1093/glycob/cwm129] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Glycosphingolipids serve as ligands for receptors involved in signal transduction and immune recognition, as exemplified by isoglobotrihexosylceramide, an antigenic ligand for T cell receptors. Mechanistic studies on the regulation of isoglobotrihexosylceramide require biochemical measurement of its lysosomal precursor, isoglobotetraglycosylceramide. It remains a challenge to distinguish between complex tetraglycosylceramide glycosphingolipid isomers with the same sugar components but diverse internal linkages. Here we established a simple and sensitive method to separate globo- and isoglobotetraglycosylceramide by MS5 ion trap mass spectrometry, and report the identification of isoglobotetraglycosylceramide in a CHO cell line transfected by iGb3 synthase, as well as in human thymus.
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Affiliation(s)
- Yunsen Li
- Department of Melanoma Medical Oncology, The University of Texas M.D. Anderson Cancer Center, Houston, TX 77054, USA
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131
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