101
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Salerno-Gonçalves R, Fernandez-Viña M, Lewinsohn DM, Sztein MB. Identification of a human HLA-E-restricted CD8+ T cell subset in volunteers immunized with Salmonella enterica serovar Typhi strain Ty21a typhoid vaccine. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2004; 173:5852-62. [PMID: 15494539 DOI: 10.4049/jimmunol.173.9.5852] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Our previous studies in volunteers immunized with Salmonella enterica serovar Typhi (S. Typhi) have suggested an important role for CD8+ T cells in host defense. In this study we describe a novel subset of nonclassical human HLA-E-restricted S. Typhi-specific CD8+ T cells derived from PBMC of Ty21a typhoid vaccinees. CD3+CD8+CD4-CD56- T cells effectively killed S. Typhi-infected targets regardless of whether they share classical HLA class I molecules with them, by a FAS-independent, granule-dependent mechanism, as evidenced by induction of granzyme B release and the blocking effects of concanamycin and strontium ions. The expression of HLA-E Ags, but not CD1-a, -b, or -c, on the membrane of S. Typhi-infected targets rendered them susceptible to lysis. Moreover, anti-HLA-E Abs partially blocked these responses. We also demonstrated that presentation of S. Typhi Ags via HLA-E could stimulate IFN-gamma production. Increases in the net frequency of IFN-gamma spot-forming cells were observed in the presence of targets coated with peptides that contain S. Typhi GroEL HLA-E binding motifs. These results demonstrate that HLA-E binds nonamer peptides derived from bacterial proteins and trigger CD8+-mediated lysis and IFN-gamma production when exposed to infected targets, raising the possibility that this novel effector mechanism might contribute to host defense against intracellular bacterial infections.
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MESH Headings
- Adult
- Antibodies, Blocking/metabolism
- Antibodies, Monoclonal/metabolism
- Antigen Presentation/immunology
- Antigen-Presenting Cells/enzymology
- Antigen-Presenting Cells/immunology
- Antigens, Bacterial/immunology
- Antigens, Bacterial/metabolism
- Binding Sites, Antibody
- CD3 Complex/biosynthesis
- CD56 Antigen/biosynthesis
- CD8-Positive T-Lymphocytes/immunology
- CD8-Positive T-Lymphocytes/microbiology
- Cell Line
- Cell Line, Transformed
- Cytoplasmic Granules/enzymology
- Cytoplasmic Granules/immunology
- Cytoplasmic Granules/microbiology
- Cytotoxicity Tests, Immunologic/methods
- HLA Antigens/immunology
- HLA Antigens/metabolism
- Histocompatibility Antigens Class I/immunology
- Histocompatibility Antigens Class I/metabolism
- Humans
- Lymphocyte Count
- Middle Aged
- Peptide Fragments/immunology
- Peptide Fragments/metabolism
- Proteasome Endopeptidase Complex/metabolism
- Protein Binding/immunology
- Protein Processing, Post-Translational/immunology
- Salmonella typhi/immunology
- T-Lymphocytes, Cytotoxic/immunology
- T-Lymphocytes, Cytotoxic/microbiology
- Typhoid-Paratyphoid Vaccines/administration & dosage
- Typhoid-Paratyphoid Vaccines/immunology
- HLA-E Antigens
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102
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Hermel E, Hart AJ, Gunduz I, Acton H, Kim C, Wurth M, Uddin S, Smith C, Fischer Lindahl K, Aldrich CJ. Polymorphism and conservation of the genes encoding Qa1 molecules. Immunogenetics 2004; 56:639-49. [PMID: 15517242 DOI: 10.1007/s00251-004-0722-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2004] [Accepted: 08/25/2004] [Indexed: 11/24/2022]
Abstract
To evaluate the polymorphism and conservation of the major histocompatibility complex class Ib molecule Qa1 in wild mouse populations, we determined the nucleotide sequence of exons 1-3 of Qa1 of eight mouse haplotypes derived from wild mice, including Mus musculus domesticus, M. m. castaneus, M. m. bactrianus, and M. spretus, as well as two t haplotypes. Our data identify eight new alleles of Qa1. Taken together with previously published data on Qa1 among the common laboratory inbred strains, and in agreement with cytotoxic T-lymphocyte, serological, and biochemical data, these results further confirm the existence of two families of Qa1 molecules, Qa1(a)-like and Qa1(b)-like, and illuminate the extreme conservation of the peptide-binding region of these molecules, even across species.
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Affiliation(s)
- Evan Hermel
- Indiana University School of Medicine, Evansville Center, 8600 University Blvd., Evansville, IN 47712-3534, USA
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103
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Lafont BAP, Buckler-White A, Plishka R, Buckler C, Martin MA. Pig-tailed macaques (Macaca nemestrina) possess six MHC-E families that are conserved among macaque species: implication for their binding to natural killer receptor variants. Immunogenetics 2004; 56:142-54. [PMID: 15148641 DOI: 10.1007/s00251-004-0663-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2003] [Revised: 02/24/2004] [Indexed: 10/26/2022]
Abstract
MHC loci encode highly polymorphic molecules involved in the presentation of self and non-self peptides to cells of the adaptive and innate immune systems. Although variable, MHC-E genes are well conserved among primates and provide signals to natural killer cells. In this study, we sequenced and analyzed MHC-E alleles of pig-tailed macaque (Macaca nemestrina), a nonhuman primate used for HIV pathogenesis and vaccine studies. Among a group of seven macaques, the characterization of eight Mane-E alleles revealed an increased number of polymorphic sites compared with human HLA-E alleles. Phylogenetic analyses of MHC-E alleles from pig-tailed macaque, rhesus monkey (Macaca mulatta) and cynomolgus macaque (Macaca fascicularis) demonstrated that the three macaque species shared six families of macaque MHC-E alleles and indicated that these families existed in the common ancestor 5.5 million years ago. Polymorphic Mane-E sites were not concentrated within the peptide-binding pockets, but were distributed throughout the entire ORF. The peptide-binding domain of Mane-E is similar to its human analogue, and peptide substrates theoretically capable of binding to Mane-E molecules were found in the leader sequence of classical Mane-A and -B molecules. Additionally, the polymorphic amino acids located in the alpha(1) and alpha(2) domains of Mane-E molecules have side chains expected to be oriented toward solvent and away from the peptide-binding groove, suggesting that some of them (positions 19, 73, 79 and 145) might be available for interaction with polymorphic receptors of natural killer cells.
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Affiliation(s)
- Bernard A P Lafont
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 4 Center Drive, Bethesda, MD 20892, USA
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104
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Kambayashi T, Kraft-Leavy JR, Dauner JG, Sullivan BA, Laur O, Jensen PE. The nonclassical MHC class I molecule Qa-1 forms unstable peptide complexes. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2004; 172:1661-9. [PMID: 14734748 DOI: 10.4049/jimmunol.172.3.1661] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The MHC class Ib molecule Qa-1 is the primary ligand for mouse CD94/NKG2A inhibitory receptors expressed on NK cells, in addition to presenting Ags to a subpopulation of T cells. CD94/NKG2A receptors specifically recognize Qa-1 bound to the MHC class Ia leader sequence-derived peptide Qdm. Qdm is the dominant peptide loaded onto Qa-1 under physiological conditions and this peptide has an optimal sequence for binding to Qa-1. Peptide dissociation experiments demonstrated that Qdm dissociates from soluble or cell surface Qa-1(b) molecules with a t(1/2) of approximately 1.5 h at 37 degrees C. In comparison, complexes of an optimal peptide (SIINFEKL) bound to the MHC class Ia molecule H-2K(b) dissociated with a t(1/2) in the range from 11 to 31 h. In contrast to K(b), the stability of cell surface Qa-1(b) molecules was independent of bound peptides, and several observations suggested that empty cell surface Qa-1(b) molecules might be unusually stable. Consistent with the rapid dissociation rate of Qdm from Qa-1(b), cells become susceptible to lysis by CD94/NKG2A(+) NK cells under conditions in which new Qa-1(b)/Qdm complexes cannot be continuously generated at the cell surface. These results support the hypothesis that Qa-1 has been selected as a specialized MHC molecule that is unable to form highly stable peptide complexes. We propose that the CD94/NKG2A-Qa-1/Qdm recognition system has evolved as a rapid sensor of the integrity of the MHC class I biosynthesis and Ag presentation pathway.
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MESH Headings
- Animals
- Antigen Presentation/genetics
- Antigen Presentation/immunology
- Antigens, CD/metabolism
- Cell Line
- Cell Membrane/immunology
- Cell Membrane/metabolism
- Cytotoxicity Tests, Immunologic
- Dendritic Cells/drug effects
- Dendritic Cells/immunology
- Dendritic Cells/metabolism
- Emetine/pharmacology
- H-2 Antigens/metabolism
- HLA Antigens/metabolism
- Half-Life
- Histocompatibility Antigens Class I/genetics
- Histocompatibility Antigens Class I/metabolism
- Humans
- Killer Cells, Natural/immunology
- Killer Cells, Natural/metabolism
- Lectins, C-Type/metabolism
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- NK Cell Lectin-Like Receptor Subfamily C
- NK Cell Lectin-Like Receptor Subfamily D
- Peptides/genetics
- Peptides/metabolism
- Protein Binding/immunology
- Receptors, Immunologic/biosynthesis
- Receptors, Immunologic/metabolism
- Receptors, Natural Killer Cell
- Recombinant Proteins/metabolism
- Transfection
- HLA-E Antigens
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Affiliation(s)
- Taku Kambayashi
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
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105
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Abstract
NK cells are crucial components of the innate immune system, capable of directly eliminating infected or tumorigenic cells and regulating down-stream adaptive immune responses. Unlike T cells, where the key recognition event driving activation is mediated by the unique T cell receptor (TCR) expressed on a given cell, NK cells express multiple activating and inhibitory cell-surface receptors (NKRs), often with overlapping ligand specificities. NKRs display two ectodomain structural homologies, either immunoglobulin- or C-type lectin-like (CTLD). The CTLD immunoreceptor NKG2D is found on NK cells but is also widely expressed on T cells and other immune system cells, providing stimulatory or co-stimulatory signals. NKG2D drives target cell killing following engagement of diverse, conditionally expressed MHC class I-like protein ligands whose expression can signal cellular distress due to infection or transformation. The symmetric, homodimeric receptor interacts with its asymmetric, monomeric ligands in similar 2:1 complexes, with an equivalent surface on each NKG2D monomer binding extensively and intimately to distinct, structurally divergent surfaces on the ligands. Thus, NKG2D ligand-binding site recognition is highly degenerate, further demonstrated by NKG2D's ability to simultaneously accommodate multiple non-conservative allelic or isoform substitutions in the ligands. In TCRs, "induced-fit" recognition explains cross-reactivity, but structural, computational, thermodynamic and kinetic analyses of multiple NKG2D-ligand pairs show that rather than classical "induced-fit" binding, NKG2D degeneracy is achieved using distinct interaction mechanisms at each rigid interface: recognition degeneracy by "rigid adaptation." While likely forming similar complexes with their ligand (HLA-E), other NKG2x NKR family members do not require such recognition degeneracy.
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MESH Headings
- Amino Acid Sequence
- Animals
- Histocompatibility Antigens Class I/immunology
- Humans
- Killer Cells, Natural/immunology
- Ligands
- Models, Molecular
- Molecular Sequence Data
- NK Cell Lectin-Like Receptor Subfamily K
- Phylogeny
- Protein Binding
- Protein Structure, Tertiary
- Receptors, Antigen, T-Cell/immunology
- Receptors, Immunologic/genetics
- Receptors, Immunologic/immunology
- Receptors, Immunologic/metabolism
- Receptors, Natural Killer Cell
- Sequence Homology, Amino Acid
- Structure-Activity Relationship
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Affiliation(s)
- Roland K Strong
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
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106
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Wada H, Matsumoto N, Maenaka K, Suzuki K, Yamamoto K. The inhibitory NK cell receptor CD94/NKG2A and the activating receptor CD94/NKG2C bind the top of HLA-E through mostly shared but partly distinct sets of HLA-E residues. Eur J Immunol 2004; 34:81-90. [PMID: 14971033 DOI: 10.1002/eji.200324432] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The human non-classical MHC class I molecule HLA-E is a ligand for both an inhibitory NK cell receptor (CD94/NKG2A) and an activating receptor (CD94/NKG2C). To identify HLA-E surface recognized by both receptors, especially to determine if both receptors recognize the same epitope, we made a series of individually Ala-substituted HLA-E proteins and analyzed their binding to CD94/NKG2A orCD94/NKG2C. Eight HLA-E mutations that significantly impaired HLA-E binding to CD94/NKG2A are all found in the top of alpha1/alpha2 domain of HLA-E. These results suggest that CD94/NKG2A binds a HLA-E surface equivalent to a NKG2D binding site on MICA. Of the eight mutations that impaired HLA-E binding to CD94/NKG2A, six significantly impaired HLA-E binding to CD94/NKG2C suggesting that CD94/NKG2C also binds a similar surface of HLA-E. Unexpectedly, the two HLA-E mutations (D69A and H155A) selectively abrogated HLA-E binding to CD94/NKG2A, not largely affected CD94/NKG2C. These results indicate that a mostly shared, but partly distinct set of HLA-E residues is discriminated by the two receptors.
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Affiliation(s)
- Haruka Wada
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, Chiba, Japan
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107
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Jensen PE, Sullivan BA, Reed-Loisel LM, Weber DA. Qa-1, a nonclassical class I histocompatibility molecule with roles in innate and adaptive immunity. Immunol Res 2004; 29:81-92. [PMID: 15181272 DOI: 10.1385/ir:29:1-3:081] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Qa-1, a nonclassical class I histocompatibility molecule expressed in mice, predominantly assembles with a single nonameric peptide, Qdm, derived from the signal sequence of certain class Ia molecules. The Qa-1/Qdm complex is the primary ligand for CD94/NKG2A inhibitory receptors expressed on a major fraction of natural killer (NK) cells. Cells become susceptible to killing by NK cells under conditions where surface expression of the Qa-1/Qdm inhibitory ligand is reduced. The CD94/NKG2 "missing-self" recognition system serves as mechanism for removing cells that have abnormalities in the intracellular machinery required for assembly and expression of class I-peptides complexes, as a consequence of viral infection, for example. Despite its highly focused peptide-binding specificity, Qa-1 also has a capacity to act as an antigen-presentation molecule for CD8+ T cells. It appears that a small subpopulation of these T cells undergoes positive selection by interaction with Qa-1 in the thymus, and they maintain their specificity for Qa-1 after maturation. The role of these unusual T cells in adaptive immune responses remains to be defined.
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Affiliation(s)
- Peter E Jensen
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA.
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108
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Lee N, Geraghty DE. HLA-F Surface Expression on B Cell and Monocyte Cell Lines Is Partially Independent from Tapasin and Completely Independent from TAP. THE JOURNAL OF IMMUNOLOGY 2003; 171:5264-71. [PMID: 14607927 DOI: 10.4049/jimmunol.171.10.5264] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In this study we examined HLA-F expression in normal cells and cell lines, with a particular focus on identifying cells that express surface protein. While HLA-F protein was expressed in a number of diverse tissues and cell lines, including bladder, skin, and liver cell lines, no surface expression could be detected in the majority of them. However, surface expression was observed on EBV-transformed lymphoblastoid cell lines and on some monocyte cell lines. Expression on B lymphoblastoid cell lines was observed, while no surface expression on normal B cells or on any peripheral blood lymphocytes could be detected. Surface expression correlated with the presence of a limited amount of endoglycosidase H (Endo H)-resistant HLA-F. However, clearly not all surface-expressed HLA-F was fully glycosylated. We further examined the requirement of HLA-F surface expression for functional TAP and tapasin molecules and identified a clear departure from the dependence shown by other class I molecules on TAP. In contrast, of the two surface glycosylation forms expressed, an Endo H-sensitive form was tapasin independent, while an Endo H-resistant form was clearly tapasin dependent. Finally, we tested whether HLA-F could be stabilized for surface expression without peptide by using the classical cold treatment for surface stabilization of empty class I. Of several cell lines tested, only MHC deletion mutant 721.221 demonstrated a typical class I phenotype, indicating that control of surface stabilization may have a genetic basis resident in the MHC.
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Affiliation(s)
- Ni Lee
- The Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
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109
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Ishitani A, Sageshima N, Lee N, Dorofeeva N, Hatake K, Marquardt H, Geraghty DE. Protein expression and peptide binding suggest unique and interacting functional roles for HLA-E, F, and G in maternal-placental immune recognition. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 171:1376-84. [PMID: 12874228 DOI: 10.4049/jimmunol.171.3.1376] [Citation(s) in RCA: 253] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In this study we focused on the structure and expression of the HLA-E, F, and G class I complexes in placental tissue. Structural analysis included an examination of the peptides bound to soluble and membrane forms of the HLA-G complex isolated directly from placenta. An important distinction was observed from HLA-G bound peptides previously isolated from transfectant cells. Thus, the number of distinct moieties bound to placental-derived proteins was substantially lower than that bound to transfectant-derived HLA-G. Indeed, a single peptide species derived from a cytokine-related protein alone accounted for 15% of the molar ratio of HLA-G bound peptide. To further examine HLA-E and its potential to bind peptide, notably that derived from HLA-G, we combined new Abs to examine expression in placental tissues for all the known forms of the nonclassical class I molecules. Whereas membrane HLA-G was found in extravillous trophoblasts, soluble HLA-G was found in all placental trophoblasts, including villous cytotrophoblasts and syncitiotrophoblasts. Further, HLA-E was found in all cells that expressed either form of HLA-G, consistent with HLA-E being complexed with the HLA-G signal sequence-derived nonamer in these cells. Finally, using new reagents specific for HLA-F, a restricted pattern of expression was observed, primarily on extravillous trophoblasts that had invaded the maternal decidua. Comparative staining indicated that HLA-F was on the surface of these cells, defining them as the first to demonstrate surface expression of this Ag and the first cell type identified to express all three nonclassical HLA class I Ags simultaneously.
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110
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Zajonc DM, Elsliger MA, Teyton L, Wilson IA. Crystal structure of CD1a in complex with a sulfatide self antigen at a resolution of 2.15 A. Nat Immunol 2003; 4:808-15. [PMID: 12833155 DOI: 10.1038/ni948] [Citation(s) in RCA: 189] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2003] [Accepted: 05/19/2003] [Indexed: 11/09/2022]
Abstract
CD1 antigens bind a variety of self and foreign lipid and glycolipid antigens for presentation to CD1-restricted T cell receptors (TCRs). Here we report the crystal structure of human CD1a in complex with a sulfatide self antigen at a resolution of 2.15 A. The lipid adopts an S-shaped conformation, with the sphingosine chain completely buried in the A' pocket and the fatty acid chain emerging from the interface of the A' pocket into the more exposed F' pocket. The headgroup is anchored in the A'-F' junction and protrudes into the F' pocket for TCR recognition. Because the A' pocket is narrow with a fixed terminus, it can act as a molecular 'ruler' to select alkyl chains of a particular length.
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Affiliation(s)
- Dirk M Zajonc
- Department of Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
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111
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Miller JD, Weber DA, Ibegbu C, Pohl J, Altman JD, Jensen PE. Analysis of HLA-E peptide-binding specificity and contact residues in bound peptide required for recognition by CD94/NKG2. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 171:1369-75. [PMID: 12874227 DOI: 10.4049/jimmunol.171.3.1369] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The MHC class Ib molecule HLA-E is the primary ligand for CD94/NKG2A-inhibitory receptors expressed on NK cells, and there is also evidence for TCR-mediated recognition of this molecule. HLA-E preferentially assembles with a homologous set of peptides derived from the leader sequence of class Ia molecules, but its capacity to bind and present other peptides remains to be fully explored. The peptide-binding motif of HLA-E was investigated by folding HLA-E in vitro in the presence of peptide libraries derived from a nonameric leader peptide sequence randomized at individual anchor positions. A high degree of selectivity was observed at four of five total anchor positions, with preference for amino acids present in HLA-E-binding peptides from class Ia leader sequences. Selectivity was also observed at the nonanchor P5 position, with preference for positively charged amino acids, suggesting that electrostatic interactions involving the P5 side chain may facilitate assembly of HLA-E peptide complexes. The observed HLA-E peptide-binding motif was strikingly similar to that previously identified for the murine class Ib molecule, Qa-1. Experiments with HLA-E tetramers bearing peptides substituted at nonanchor positions demonstrated that P5 and P8 are primary contact residues for interaction with CD94/NKG2 receptors. A conservative replacement of Arg for Lys at P5 completely abrogated binding to CD94/NKG2. Despite conservation of peptide-binding specificity in HLA-E and Qa-1, cross-species tetramer-staining experiments demonstrated that the interaction surfaces on CD94/NKG2 and the class Ib ligands have diverged between primates and rodents.
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MESH Headings
- Amino Acid Motifs/genetics
- Amino Acid Motifs/immunology
- Amino Acid Substitution/genetics
- Animals
- Antigens, CD/metabolism
- Binding, Competitive/genetics
- Binding, Competitive/immunology
- Epitopes/genetics
- Epitopes/metabolism
- Escherichia coli/genetics
- Escherichia coli/immunology
- HLA Antigens/genetics
- HLA Antigens/metabolism
- Histocompatibility Antigens Class I/genetics
- Histocompatibility Antigens Class I/metabolism
- Humans
- Immunoassay
- Killer Cells, Natural/immunology
- Killer Cells, Natural/metabolism
- Lectins, C-Type/antagonists & inhibitors
- Lectins, C-Type/metabolism
- Lysine/genetics
- Lysine/metabolism
- Macaca mulatta
- Mice
- Mice, Inbred C57BL
- NK Cell Lectin-Like Receptor Subfamily C
- NK Cell Lectin-Like Receptor Subfamily D
- Oligopeptides/chemical synthesis
- Oligopeptides/genetics
- Oligopeptides/immunology
- Oligopeptides/metabolism
- Peptide Library
- Protein Binding/genetics
- Protein Binding/immunology
- Protein Folding
- Receptors, Immunologic/antagonists & inhibitors
- Receptors, Immunologic/metabolism
- Receptors, Natural Killer Cell
- Recombinant Proteins/chemical synthesis
- Recombinant Proteins/metabolism
- HLA-E Antigens
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Affiliation(s)
- Joseph D Miller
- Emory Vaccine Research Center, Emory University School of Medicine, Atlanta, GA 30322, USA
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112
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Davies A, Kalb S, Liang B, Aldrich CJ, Lemonnier FA, Jiang H, Cotter R, Soloski MJ. A peptide from heat shock protein 60 is the dominant peptide bound to Qa-1 in the absence of the MHC class Ia leader sequence peptide Qdm. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:5027-33. [PMID: 12734347 DOI: 10.4049/jimmunol.170.10.5027] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The MHC class Ib molecule Qa-1 binds specifically and predominantly to a single 9-aa peptide (AMAPRTLLL) derived from the leader sequence of many MHC class Ia proteins. This peptide is referred to as Qdm. In this study, we report the isolation and sequencing of a heat shock protein 60-derived peptide (GMKFDRGYI) from Qa-1. This peptide is the dominant peptide bound to Qa-1 in the absence of Qdm. A Qa-1-restricted CTL clone recognizes this heat shock protein 60 peptide, further verifying that it binds to Qa-1 and a peptide from the homologous Salmonella typhimurium protein GroEL (GMQFDRGYL). These observations have implications for how Qa-1 can influence NK cell and T cell effector function via the TCR and CD94/NKG2 family members, and how this effect can change under conditions that cause the peptides bound to Qa-1 to change.
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Affiliation(s)
- Adrian Davies
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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113
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Cardoso CS, de Sousa M. HFE, the MHC and hemochromatosis: paradigm for an extended function for MHC class I. TISSUE ANTIGENS 2003; 61:263-75. [PMID: 12753664 DOI: 10.1034/j.1399-0039.2003.00065.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
HFE was discovered as the hereditary hemochromatosis (HH) gene. It is located on chromosome 6 (6p21.3), 4Mb telomeric to the HLA-A locus, and its product has a structure similar to MHC class I molecules. HFE encodes two frequent mutations: C282Y and H63D. One of these (C282Y) is present in a large proportion of Caucasian HH patients. HFE has a tissue distribution compatible with a role in iron absorption (intestine), recycling (macrophages) and transport to the fetus (placenta).
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Affiliation(s)
- C S Cardoso
- Molecular Immunology, Institute for Molecular and Cell Biology, Oporto, Portugal Molecular Pathology and Immunology, Instituto de Ciências Biomédicas Abel Salazar, OPorto, Portugal
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114
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Strong RK, Holmes MA, Li P, Braun L, Lee N, Geraghty DE. HLA-E allelic variants. Correlating differential expression, peptide affinities, crystal structures, and thermal stabilities. J Biol Chem 2003; 278:5082-90. [PMID: 12411439 DOI: 10.1074/jbc.m208268200] [Citation(s) in RCA: 236] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Previous studies of HLA-E allelic polymorphism have indicated that balancing selection may be acting to maintain two major alleles in most populations, indicating that a functional difference may exist between the alleles. The alleles differ at only one amino acid position, where an arginine at position 107 in HLA-E*0101 (E(R)) is replaced by a glycine in HLA-E*0103 (E(G)). To investigate possible functional differences, we have undertaken a study of the physical and biochemical properties of these two proteins. By comparing expression levels, we found that whereas steady-state protein levels were similar, the two alleles did in fact differ with respect to cell surface levels. To help explain this difference, we undertook studies of the relative differences in peptide affinity, complex stability, and three-dimensional structure between the alleles. The crystal structures for HLA-E(G) complexed with two distinct peptides were determined, and both were compared with the HLA-E(R) structure. No significant differences in the structure of HLA-E were induced as a result of binding different peptides or by the allelic substitution at position 107. However, there were clear differences in the relative affinity for peptide of each heavy chain, which correlated with and may be explained by differences between their thermal stabilities. These differences were completely consistent with the relative levels of the HLA-E alleles on the cell surface and may indeed correlate with functional differences. This in turn may help explain the apparent balancing selection acting on this locus.
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Affiliation(s)
- Roland K Strong
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA.
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115
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Long EO, Rajagopalan S. Stress signals activate natural killer cells. J Exp Med 2002; 196:1399-402. [PMID: 12461075 PMCID: PMC2194264 DOI: 10.1084/jem.20021747] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2002] [Revised: 10/22/2002] [Accepted: 10/21/2002] [Indexed: 12/01/2022] Open
Affiliation(s)
- Eric O Long
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12441 Parklawn Drive, Rockville, MD 20852, USA.
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116
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Michaëlsson J, Teixeira de Matos C, Achour A, Lanier LL, Kärre K, Söderström K. A signal peptide derived from hsp60 binds HLA-E and interferes with CD94/NKG2A recognition. J Exp Med 2002; 196:1403-14. [PMID: 12461076 PMCID: PMC2194258 DOI: 10.1084/jem.20020797] [Citation(s) in RCA: 188] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2002] [Revised: 07/26/2002] [Accepted: 09/13/2002] [Indexed: 11/21/2022] Open
Abstract
Human histocompatibility leukocyte antigen (HLA)-E is a nonclassical major histocompatibility complex (MHC) class I molecule which presents a restricted set of nonameric peptides, derived mainly from the signal sequence of other MHC class I molecules. It interacts with CD94/NKG2 receptors expressed on the surface of natural killer (NK) cells and T cell subsets. Here we demonstrate that HLA-E also presents a peptide derived from the leader sequence of human heat shock protein 60 (hsp60). This peptide gains access to HLA-E intracellularly, resulting in up-regulated HLA-E/hsp60 signal peptide cell-surface levels on stressed cells. Notably, HLA-E molecules in complex with the hsp60 signal peptide are no longer recognized by CD94/NKG2A inhibitory receptors. Thus, during cellular stress an increased proportion of HLA-E molecules may bind the nonprotective hsp60 signal peptide, leading to a reduced capacity to inhibit a major NK cell population. Such stress induced peptide interference would gradually uncouple CD94/NKG2A inhibitory recognition and provide a mechanism for NK cells to detect stressed cells in a peptide-dependent manner.
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Affiliation(s)
- Jakob Michaëlsson
- Microbiology and Tumor Biology Center, Karolinska Institutet, 171 77 Stockholm, Sweden
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117
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Allan DSJ, Lepin EJM, Braud VM, O'Callaghan CA, McMichael AJ. Tetrameric complexes of HLA-E, HLA-F, and HLA-G. J Immunol Methods 2002; 268:43-50. [PMID: 12213342 DOI: 10.1016/s0022-1759(02)00199-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
HLA-E, HLA-F, and HLA-G are human nonclassical MHC class Ib molecules. To study the function and identify potential ligands of these molecules, we constructed tetrameric complexes. In this brief review, we discuss the methods used to produce such tetramers and the interesting results they provided. HLA-E tetramers bound to natural killer (NK) cells and T cells, allowing the identification of CD94/NKG2 molecules as receptors for HLA-E. HLA-G tetramers interacted with immunoglobulin-like transcript-2 (ILT2) and ILT4 receptors, aiding the understanding of HLA-G function during pregnancy. Tetrameric complexes of HLA-F also bound to ILT2 and ILT4.
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Affiliation(s)
- David S J Allan
- Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Oxford, OX3 9DS, UK.
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118
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Abstract
Natural killer (NK) cells have been known for a long time to be a very important component of the innate immune system. However, it is only during the last 10 years that knowledge of their receptors has emerged. Described in the present review are those receptor families killer inhibitory receptor (KIR) (belonging to the immunoglobulin superfamily), and killer lectin like receptor (KLR) CD94/NKG2, that both use HLA as a ligand and have inhibiting and activating types of receptors, and natural cytotoxic receptors (NCR) which do not associate with HLA. Association of the receptor gives rise to either an inhibiting or activating signal leading to either failure or success in lysing a target cell. The KIR receptors are very polymorphic both in the number of genes expressed in an individual and the alleles present for a gene. They would appear to have had a rapid evolution compared to the CD94/NKG2 receptors. The roles that NK cells and their receptors have with various facets of transplantation, disease, pregnancy and control of virus infection in humans are described.
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MESH Headings
- Animals
- Antigens, CD/immunology
- Autoimmune Diseases/immunology
- Chromosomes, Human, Pair 19/genetics
- Cytotoxicity, Immunologic
- Evolution, Molecular
- Female
- HLA Antigens/immunology
- Histocompatibility Antigens Class I/immunology
- Humans
- Killer Cells, Lymphokine-Activated/immunology
- Killer Cells, Natural/immunology
- Lectins, C-Type/immunology
- Ligands
- Lymphocyte Activation
- Mice
- Models, Molecular
- NK Cell Lectin-Like Receptor Subfamily C
- NK Cell Lectin-Like Receptor Subfamily D
- Pregnancy
- Protein Conformation
- Receptors, Immunologic/genetics
- Receptors, Immunologic/immunology
- Receptors, KIR
- Receptors, Natural Killer Cell
- Transplantation Immunology
- HLA-E Antigens
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Affiliation(s)
- Derek Middleton
- Northern Ireland Regional Histocompatibility and Immunogenetics Laboratory, Belfast City Hospital, Belfast, UK.
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119
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Guethlein LA, Flodin LR, Adams EJ, Parham P. NK cell receptors of the orangutan (Pongo pygmaeus): a pivotal species for tracking the coevolution of killer cell Ig-like receptors with MHC-C. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 169:220-9. [PMID: 12077248 DOI: 10.4049/jimmunol.169.1.220] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CD94, NKG2, Ly49, and killer cell Ig-like receptor (KIR) expressed by orangutan peripheral blood cells were examined by cloning and sequencing cDNA from a panel of individuals. Orthologs of human CD94, NKG2A, D, and F were defined. NKG2C and E are represented by one gene, Popy-NKG2CE, that is equidistant from the two human genes. Several Popy-CD94, NKG2A, and NKG2CE alleles were defined. Popy-Ly49L is expressed in cultured NK cells and has a sequence consistent with it encoding a functional receptor. Orangutan KIR corresponding to the three KIR lineages expressed in humans and chimpanzees were defined. Popy-KIR2DL4 of lineage I is the only ortholog of a human or chimpanzee KIR, but in all individuals examined, the transcripts of this gene produced premature termination, either in the D2 domain or at the beginning of the cytoplasmic domain. Ten Popy-KIR3DL and one Popy-KIR3DS of lineage II are all closely related, but represent the products of at least two genes. The two Popy-KIR2DL and four Popy-KIR2DS of lineage III also represent two genes, both being more related to KIR2DS4 than to other human and chimpanzee KIR of lineage III. The Popy-KIR2D include ones predicted to be specific for the C1 epitope of MHC-C, but none specific for C2. This correlates with the observation that all orangutan MHC-C allotypes examined have the C1 motif.
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MESH Headings
- Alleles
- Amino Acid Motifs/genetics
- Amino Acid Motifs/immunology
- Amino Acid Sequence
- Animals
- Antigens, CD/chemistry
- Antigens, CD/genetics
- Antigens, Ly
- Evolution, Molecular
- HLA-C Antigens/chemistry
- HLA-C Antigens/genetics
- Humans
- Killer Cells, Natural/immunology
- Killer Cells, Natural/metabolism
- Lectins/chemistry
- Lectins/genetics
- Lectins, C-Type
- Male
- Membrane Glycoproteins/chemistry
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/physiology
- Molecular Sequence Data
- NK Cell Lectin-Like Receptor Subfamily C
- NK Cell Lectin-Like Receptor Subfamily D
- Phylogeny
- Pongo pygmaeus/genetics
- Pongo pygmaeus/immunology
- Protein Binding/genetics
- Protein Binding/immunology
- Receptors, Immunologic/chemistry
- Receptors, Immunologic/genetics
- Receptors, Immunologic/metabolism
- Receptors, KIR
- Receptors, KIR2DL4
- Receptors, Natural Killer Cell
- Sequence Homology, Amino Acid
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Affiliation(s)
- Lisbeth A Guethlein
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305-5126, USA
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120
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Natarajan K, Dimasi N, Wang J, Mariuzza RA, Margulies DH. Structure and function of natural killer cell receptors: multiple molecular solutions to self, nonself discrimination. Annu Rev Immunol 2002; 20:853-85. [PMID: 11861620 DOI: 10.1146/annurev.immunol.20.100301.064812] [Citation(s) in RCA: 235] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In contrast to T cell receptors, signal transducing cell surface membrane molecules involved in the regulation of responses by cells of the innate immune system employ structures that are encoded in the genome rather than generated by somatic recombination and that recognize either classical MHC-I molecules or their structural relatives (such as MICA, RAE-1, or H-60). Considerable progress has recently been made in our understanding of molecular recognition by such molecules based on the determination of their three-dimensional structure, either in isolation or in complex with their MHC-I ligands. Those best studied are the receptors that are expressed on natural killer (NK) cells, but others are found on populations of T cells and other hematopoietic cells. These molecules fall into two major structural classes, those of the immunoglobulin superfamily (KIRs and LIRs) and of the C-type lectin-like family (Ly49, NKG2D, and CD94/NKG2). Here we summarize, in a functional context, the structures of the murine and human molecules that have recently been determined, with emphasis on how they bind different regions of their MHC-I ligands, and how this allows the discrimination of tumor or virus-infected cells from normal cells of the host.
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MESH Headings
- Alleles
- Amino Acid Sequence
- Animals
- Antigens, CD/chemistry
- Antigens, CD/genetics
- Antigens, CD/metabolism
- Antigens, Ly
- Histocompatibility Antigens Class I/chemistry
- Histocompatibility Antigens Class I/metabolism
- Humans
- Killer Cells, Natural/immunology
- Lectins, C-Type
- Leukocyte Immunoglobulin-like Receptor B1
- Macromolecular Substances
- Membrane Glycoproteins/chemistry
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/metabolism
- Mice
- Models, Molecular
- Molecular Sequence Data
- Molecular Structure
- NK Cell Lectin-Like Receptor Subfamily D
- Receptors, Immunologic/chemistry
- Receptors, Immunologic/genetics
- Receptors, Immunologic/metabolism
- Receptors, KIR
- Receptors, KIR2DL1
- Receptors, NK Cell Lectin-Like
- Self Tolerance
- Sequence Homology, Amino Acid
- Signal Transduction
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Affiliation(s)
- Kannan Natarajan
- Molecular Biology Section, Laboratory of Immunology, NIAID, NIH, Bethesda, Maryland 20892-1892, USA.
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121
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Matsunami K, Miyagawa S, Nakai R, Yamada M, Shirakura R. Modulation of the leader peptide sequence of the HLA-E gene up-regulates its expression and down-regulates natural killer cell-mediated swine endothelial cell lysis. Transplantation 2002; 73:1582-9. [PMID: 12042643 DOI: 10.1097/00007890-200205270-00010] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The inhibitory function of HLA class I molecules, HLA-G1 and HLA-E, on natural killer (NK) cell-mediated cytolysis has previously been reported. In this study, we report on a study of the effects of the co-expression of these molecules on the inhibition of NK cell-mediated cytolysis, using a newly constructed gene. METHODS Complementary DNA (cDNA) of HLA-G (G1 and G3), HLA-E, and human beta2-microglobulin (hbeta2m) were prepared and transfected into swine endothelial cell (SEC) and Chinese hamster ovarian tumor (CHO) cell. The leader peptide sequences of HLA-G1 and HLA -E genes were changed to VMAPRTLFL or VMAPRTLVL, which corresponds to the original HLA-G1 and HLA-A2. The cell surface expression of the modified genes was evaluated by flow cytometry, and NK cell-mediated cytolysis by human peripheral blood mononuclear cells (PBMC) was assessed. RESULTS The transfectant with the hbeta2m and HLA-G1 genes showed a clear expression of the HLA-G1 molecule and had an inhibitory effect on NK cell-mediated SEC lysis. Whereas neither the transfectant with the hbeta2m and HLA-E genes, nor that with the hbeta2m and HLA-G3 genes, expressed the HLA molecule on SEC, the transfectant with triple genes, hbeta2m, HLA-E, and HLA-G3, expressed the HLA-E molecule and also inhibited NK-mediated SEC lysis. Conversely, the modification of the leader sequence of the HLA-E gene successfully induced the expression of the HLA-E molecule on the SEC surface. Furthermore, the transfectant expressed both HLA-G1 and HLA-E molecules, thus efficiently enhancing the inhibition of NK-mediated SEC lysis. CONCLUSION The co-expression of HLA-G1 and HLA-E molecules with the modified genes has potential for use in preventing xenograft rejection, as mediated by human NK cells.
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Affiliation(s)
- Katsuyoshi Matsunami
- Division of Organ Transplantation, Department of Regenerative Medicine, Osaka University Graduate School of Medicine, Japan
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122
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García P, Llano M, de Heredia AB, Willberg CB, Caparrós E, Aparicio P, Braud VM, López-Botet M. Human T cell receptor-mediated recognition of HLA-E. Eur J Immunol 2002; 32:936-44. [PMID: 11920559 DOI: 10.1002/1521-4141(200204)32:4<936::aid-immu936>3.0.co;2-m] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The HLA-E class Ib molecule presents hydrophobic peptides derived from the leader sequences of other class I molecules, constituting the ligands for CD94/NKG2 lectin-like receptors. Along the course of our studies on human CD94+ T cells, we characterized an alpha beta CD8+CD94/NKG2C+ CTL clone (K14). In cytolytic assays against the murine TAP-deficient RMA-S cells transfected with human beta2 microglobulin and HLA-E (RMA-S/HLA-E), loaded with different synthetic peptides, K14 displayed a pattern of specific recognition distinct to that observed in CD94/NKG2C+ NK clones tested in parallel. RMA-S/HLA-E cells loaded with some but not all HLA class I leader sequence peptides were efficiently recognized by K14 but not by CD94/NKG2C clones, andvice versa. Remarkably, K14 also reacted with HLA-E loaded with a peptide derived from the BZLF-1 Epstein-Barr virus protein. Anti-CD94 mAb did not prevent K14 cytotoxicity against RMA-S/HLA-E cells, whereas incubation with anti-clonotypic mAb specific for the K14 TCR markedly inhibited lysis. Soluble HLA-E tetramers refolded with different peptides (i.e. VMAPRTVLL, VMAPRTLIL, VMAPRTLFL) specifically stained K14 cells. HLA-E tetramer binding was minimally reduced by pretreatment with anti-CD94 mAb alone, but was completely prevented in combination with anti-clonotypic mAb. Altogether, the data unequivocally imply the generation of human T cells potentially recognizing through the alpha beta TCR HLA-E molecules that bind to class I- and virus-derived peptides.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily B, Member 3
- ATP-Binding Cassette Transporters/immunology
- Animals
- Antibodies, Monoclonal/immunology
- Antigen Presentation
- Antigens, CD/immunology
- Antigens, Viral/chemistry
- Antigens, Viral/immunology
- Biopolymers
- Clone Cells/immunology
- Cytotoxicity, Immunologic
- DNA-Binding Proteins/chemistry
- DNA-Binding Proteins/immunology
- HLA Antigens/genetics
- HLA Antigens/immunology
- HLA-A Antigens/chemistry
- HLA-A Antigens/immunology
- HLA-B Antigens/chemistry
- HLA-B Antigens/immunology
- HLA-C Antigens/chemistry
- HLA-C Antigens/immunology
- Herpesvirus 4, Human/immunology
- Histocompatibility Antigens Class I/genetics
- Histocompatibility Antigens Class I/immunology
- Humans
- Killer Cells, Natural/immunology
- Lectins, C-Type
- Membrane Glycoproteins/immunology
- Mice
- NK Cell Lectin-Like Receptor Subfamily D
- Peptide Fragments/immunology
- Protein Sorting Signals
- Receptors, Antigen, T-Cell, alpha-beta/immunology
- Recombinant Fusion Proteins/immunology
- Trans-Activators/chemistry
- Trans-Activators/immunology
- Transfection
- Viral Proteins
- beta 2-Microglobulin/genetics
- HLA-E Antigens
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Affiliation(s)
- Pilar García
- DCEXS (Inmunología), Universitat Pompeu Fabra, Barcelona, Spain
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123
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He X, Tabaczewski P, Ho J, Stroynowski I, Garcia KC. Promiscuous antigen presentation by the nonclassical MHC Ib Qa-2 is enabled by a shallow, hydrophobic groove and self-stabilized peptide conformation. Structure 2001; 9:1213-24. [PMID: 11738047 DOI: 10.1016/s0969-2126(01)00689-x] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Qa-2 is a nonclassical MHC Ib antigen, which has been implicated in both innate and adaptive immune responses, as well as embryonic development. Qa-2 has an unusual peptide binding specificity in that it requires two dominant C-terminal anchor residues and is capable of associating with a substantially more diverse array of peptide sequences than other nonclassical MHC. RESULTS We have determined the crystal structure, to 2.3 A, of the Q9 gene of murine Qa-2 complexed with a self-peptide derived from the L19 ribosomal protein, which is abundant in the pool of peptides eluted from the Q9 groove. The 9 amino acid peptide is bound high in a shallow, hydrophobic binding groove of Q9, which is missing a C pocket. The peptide makes few specific contacts and exhibits extremely poor shape complementarity to the MHC groove, which facilitates the presentation of a degenerate array of sequences. The L19 peptide is in a centrally bulged conformation that is stabilized by intramolecular interactions from the invariant P7 histidine anchor residue and by a hydrophobic core of preferred secondary anchor residues that have minimal interaction with the MHC. CONCLUSIONS Unexpectedly, the preferred secondary peptide residues that exhibit tenuous contact with Q9 contribute significantly to the overall stability of the peptide-MHC complex. The structure of this complex implies a "conformational" selection by Q9 for peptide residues that optimally stabilize the large bulge rather than making intimate contact with the MHC pockets.
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Affiliation(s)
- X He
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
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124
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Radaev S, Rostro B, Brooks AG, Colonna M, Sun PD. Conformational plasticity revealed by the cocrystal structure of NKG2D and its class I MHC-like ligand ULBP3. Immunity 2001; 15:1039-49. [PMID: 11754823 DOI: 10.1016/s1074-7613(01)00241-2] [Citation(s) in RCA: 123] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
NKG2D is known to trigger the natural killer (NK) cell lysis of various tumor and virally infected cells. In the NKG2D/ULBP3 complex, the structure of ULBP3 resembles the alpha1 and alpha2 domains of classical MHC molecules without a bound peptide. The lack of alpha3 and beta2m domains is compensated by replacing two hydrophobic patches at the underside of the class I MHC-like beta sheet floor with a group of hydrophilic and charged residues in ULBP3. NKG2D binds diagonally across the ULBP3 alpha helices, creating a complementary interface, an asymmetrical subunit orientation, and local conformational adjustments in the receptor. The interface is stabilized primarily by hydrogen bonds and hydrophobic interactions. Unlike the KIR receptors that recognize a conserved HLA region by a lock-and-key mechanism, NKG2D recognizes diverse ligands by an induced-fit mechanism.
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MESH Headings
- Amino Acid Sequence
- Antigens, CD/metabolism
- Carrier Proteins/chemistry
- Carrier Proteins/metabolism
- Crystallization
- Crystallography, X-Ray
- GPI-Linked Proteins
- HLA Antigens/chemistry
- HLA-C Antigens/chemistry
- Hemochromatosis Protein
- Histocompatibility Antigens Class I/chemistry
- Histocompatibility Antigens Class I/metabolism
- Humans
- Hydrogen Bonding
- Intercellular Signaling Peptides and Proteins
- Killer Cells, Natural/immunology
- Lectins, C-Type
- Ligands
- Macromolecular Substances
- Membrane Glycoproteins/metabolism
- Membrane Proteins
- Models, Molecular
- Molecular Sequence Data
- Multigene Family
- NK Cell Lectin-Like Receptor Subfamily D
- NK Cell Lectin-Like Receptor Subfamily K
- Protein Binding
- Protein Conformation
- Protein Structure, Tertiary
- Receptors, Antigen, T-Cell, alpha-beta/chemistry
- Receptors, Fc/chemistry
- Receptors, Immunologic/chemistry
- Receptors, Immunologic/genetics
- Receptors, Immunologic/metabolism
- Receptors, Natural Killer Cell
- Recombinant Fusion Proteins/chemistry
- Sequence Alignment
- Sequence Homology, Amino Acid
- Structure-Activity Relationship
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Affiliation(s)
- S Radaev
- Structural Biology Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12441 Parklawn Drive, Rockville, MD 20852, USA
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125
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Stevens J, Joly E, Trowsdale J, Butcher GW. Peptide binding characteristics of the non-classical class Ib MHC molecule HLA-E assessed by a recombinant random peptide approach. BMC Immunol 2001; 2:5. [PMID: 11432755 PMCID: PMC33820 DOI: 10.1186/1471-2172-2-5] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2001] [Accepted: 06/20/2001] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Increasing evidence suggests that the effect of HLA-E on Natural Killer (NK) cell activity can be affected by the nature of the peptides bound to this non-classical, MHC class Ib molecule. However, its reduced cell surface expression, and until recently, the lack of specific monoclonal antibodies hinder studying the peptide-binding specificity HLA-E. RESULTS An in vitro refolding system was used to assess binding of recombinant HLA-E to either specific peptides or a nonamer random peptide library. Peptides eluted from HLA-E molecules refolded around the nonamer library were then used to determine a binding motif for HLA-E. Hydrophobic and non-charged amino acids were found to predominate along the peptide motif, with a leucine anchor at P9, but surprisingly there was no methionine preference at P2, as suggested by previous studies. CONCLUSIONS Compared to the results obtained with rat classical class Ia MHC molecules, RT1-A1c and RT1-Au, HLA-E appears to refold around a random peptide library to reduced but detectable levels, suggesting that this molecule's specificity is tight but probably not as exquisite as has been previously suggested. This, and a previous report that it can associate with synthetic peptides carrying a viral sequence, suggests that HLA-E, similar to its mouse counterpart (Qa-1b), could possibly bind peptides different from MHC class I leader peptides and present them to T lymphocytes.
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Affiliation(s)
- James Stevens
- Laboratory of Functional Immunogenetics, The Babraham Institute, Cambridge CB2 4AT, UK
- Department of Pathology, Division of Immunology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Etienne Joly
- Laboratory of Functional Immunogenetics, The Babraham Institute, Cambridge CB2 4AT, UK
- UPCM, CNRS UPS 2163, CHU Purpan, 31300 Toulouse, France
| | - John Trowsdale
- Department of Pathology, Division of Immunology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Geoffrey W Butcher
- Laboratory of Functional Immunogenetics, The Babraham Institute, Cambridge CB2 4AT, UK
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126
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Li P, Morris DL, Willcox BE, Steinle A, Spies T, Strong RK. Complex structure of the activating immunoreceptor NKG2D and its MHC class I-like ligand MICA. Nat Immunol 2001; 2:443-51. [PMID: 11323699 DOI: 10.1038/87757] [Citation(s) in RCA: 291] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The major histocompatibility complex (MHC) class I homolog, MICA, is a stress-inducible ligand for NKG2D, a C-type lectin-like activating immunoreceptor. The crystal structure of this ligand-receptor complex that we report here reveals an NKG2D homodimer bound to a MICA monomer in an interaction that is analogous to that seen in T cell receptor-MHC class I protein complexes. Similar surfaces on each NKG2D monomer interact with different surfaces on either the alpha1 or alpha2 domains of MICA. The binding interactions are large in area and highly complementary. The central section of the alpha2-domain helix, disordered in the structure of MICA alone, is ordered in the complex and forms part of the NKG2D interface. The extensive flexibility of the interdomain linker of MICA is shown by its altered conformation when crystallized alone or in complex with NKG2D.
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Affiliation(s)
- P Li
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109 USA
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127
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Affiliation(s)
- S Bahram
- Centre de Recherche d'Immunologie et d'Hématologie, Strasbourg, France
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128
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Gays F, Fraser KP, Toomey JA, Diamond AG, Millrain MM, Dyson PJ, Brooks CG. Functional analysis of the molecular factors controlling Qa1-mediated protection of target cells from NK lysis. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:1601-10. [PMID: 11160201 DOI: 10.4049/jimmunol.166.3.1601] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CD94/NKG2 receptors on mouse NK cells recognize the nonclassical class I molecule Qa1 and can deliver inhibitory signals that prevent NK cells from lysing Qa1-expressing cells. However, the exact circumstances under which Qa1 protects cells from NK lysis and, in particular, the role of the dominant Qa1-associated peptide, Qdm, are unclear. In this study, we examined in detail the lysis of Qa1-expressing cells by fetal NK cells that express CD94/NKG2 receptors for Qa1 but that lack receptors for classical class I molecules. Whereas mouse L cells and human C1R cells transfected with Qa1 were resistant to lysis by these effectors, Qa1-transfected TAP-deficient human T2 cells showed no resistance despite expressing high levels of surface Qa1. However, these cells could be efficiently protected by exposure to low concentrations of Qdm peptide or certain Qdm-related peptides. By contrast, even prolonged exposure of TAP-deficient RMA/S cells to high doses of Qdm peptide failed to induce levels of surface Qa1 detectable with a Qa1-specific mAb or to protect them from NK lysis, although such treatment induced sensitivity to lysis by Qa1-specific CTL. Collectively, these findings indicate that high surface expression of Qa1 is necessary but not sufficient for protection, and that effective protection requires the expression of sufficient levels of suitable Qa1-peptide complexes to overcome activatory signals. Results obtained with a series of substituted Qdm peptides suggest that residues at positions 3, 4, 5, and 8 of the Qdm sequence, AMAPRTLLL, are important for recognition of Qa1-Qdm complexes by inhibitory CD94/NKG2 receptors.
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MESH Headings
- ATP-Binding Cassette Transporters/genetics
- Animals
- Antigens, CD/metabolism
- Cell Line
- Cytotoxicity Tests, Immunologic/methods
- Cytotoxicity, Immunologic/genetics
- Fetus
- Histocompatibility Antigens Class I/biosynthesis
- Histocompatibility Antigens Class I/genetics
- Histocompatibility Antigens Class I/immunology
- Histocompatibility Antigens Class I/metabolism
- Humans
- Killer Cells, Natural/immunology
- Killer Cells, Natural/metabolism
- L Cells
- Lectins, C-Type
- Membrane Glycoproteins/metabolism
- Mice
- Mice, Inbred C57BL
- NK Cell Lectin-Like Receptor Subfamily C
- NK Cell Lectin-Like Receptor Subfamily D
- Peptide Fragments/immunology
- Peptide Fragments/metabolism
- Peptides/immunology
- Peptides/metabolism
- Peptides/pharmacology
- Protein Binding/immunology
- Protein Sorting Signals
- Receptors, Antigen/biosynthesis
- Receptors, Immunologic/metabolism
- Receptors, Natural Killer Cell
- Species Specificity
- Temperature
- Transfection
- Tumor Cells, Cultured
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Affiliation(s)
- F Gays
- Department of Microbiology and Immunology, The Medical School, Newcastle, United Kingdom
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129
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Lepin EJ, Bastin JM, Allan DS, Roncador G, Braud VM, Mason DY, van der Merwe PA, McMichael AJ, Bell JI, Powis SH, O'Callaghan CA. Functional characterization of HLA-F and binding of HLA-F tetramers to ILT2 and ILT4 receptors. Eur J Immunol 2000; 30:3552-61. [PMID: 11169396 DOI: 10.1002/1521-4141(200012)30:12<3552::aid-immu3552>3.0.co;2-l] [Citation(s) in RCA: 160] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
HLA-F is a human non-classical MHC molecule. Recombinant HLA-F heavy chain was refolded with 2-microglobulin to form a stable complex. This complex was used as an immunogen to produce a highly specific, high-affinity monoclonal antibody (FG1) that was used to study directly the cellular biology and tissue distribution of HLA-F. HLA-F has a restricted pattern of tissue expression in tonsil, spleen, and thymus. HLA-F could be immunoprecipitated from B cell lines and from HUT-78, a T cell line. HLA-F binds TAP, but unlike the classical human class I molecules, was undetected at the cell surface. HLA-F tetramers stain peripheral blood monocytes and B cells. HLA-F tetramer binding could be conferred on non-binding cells by transfection with the inhibitory receptors ILT2 and ILT4. Surface plasmon resonance studies demonstrated a direct molecular interaction of HLA-F with ILT2 and ILT4. These results, together with structural predictions based on the sequence of HLA-F, suggest that HLA-F may be a peptide binding molecule and may reach the cell surface under favorable conditions, which may include the presence of specific peptide or peptides. At the cell surface it would be capable of interacting with LIR1 (ILT2) and LIR2 (ILT4) receptors and so altering the activation threshold of immune effector cells.
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Affiliation(s)
- E J Lepin
- Centre for Nephrology, Royal Free and University College Medical School, University College London, London, GB
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130
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Kraft JR, Vance RE, Pohl J, Martin AM, Raulet DH, Jensen PE. Analysis of Qa-1(b) peptide binding specificity and the capacity of CD94/NKG2A to discriminate between Qa-1-peptide complexes. J Exp Med 2000; 192:613-24. [PMID: 10974028 PMCID: PMC2193274 DOI: 10.1084/jem.192.5.613] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The major histocompatibility complex class Ib protein, Qa-1(b), serves as a ligand for murine CD94/NKG2A natural killer (NK) cell inhibitory receptors. The Qa-1(b) peptide-binding site is predominantly occupied by a single nonameric peptide, Qa-1 determinant modifier (Qdm), derived from the leader sequence of H-2D and L molecules. Five anchor residues were identified in this study by measuring the peptide-binding affinities of substituted Qdm peptides in experiments with purified recombinant Qa-1(b). A candidate peptide-binding motif was determined by sequence analysis of peptides eluted from Qa-1 that had been folded in the presence of random peptide libraries or pools of Qdm derivatives randomized at specific anchor positions. The results indicate that Qa-1(b) can bind a diverse repertoire of peptides but that Qdm has an optimal primary structure for binding Qa-1(b). Flow cytometry experiments with Qa-1(b) tetramers and NK target cell lysis assays demonstrated that CD94/NKG2A discriminates between Qa-1(b) complexes containing peptides with substitutions at nonanchor positions P4, P5, or P8. Our findings suggest that it may be difficult for viruses to generate decoy peptides that mimic Qdm and raise the possibility that competitive replacement of Qdm with other peptides may provide a novel mechanism for activation of NK cells.
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Affiliation(s)
- Jennifer R. Kraft
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Russell E. Vance
- Department of Molecular and Cell Biology and Cancer Research Laboratory, University of California at Berkeley, Berkeley, California 94720
| | - Jan Pohl
- Microchemical Facility, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Amy M. Martin
- Microchemical Facility, Emory University School of Medicine, Atlanta, Georgia 30322
| | - David H. Raulet
- Department of Molecular and Cell Biology and Cancer Research Laboratory, University of California at Berkeley, Berkeley, California 94720
| | - Peter E. Jensen
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia 30322
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131
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Soloski MJ, Szperka ME, Davies A, Wooden SL. Host immune response to intracellular bacteria: A role for MHC-linked class-Ib antigen-presenting molecules. PROCEEDINGS OF THE SOCIETY FOR EXPERIMENTAL BIOLOGY AND MEDICINE. SOCIETY FOR EXPERIMENTAL BIOLOGY AND MEDICINE (NEW YORK, N.Y.) 2000; 224:231-9. [PMID: 10964257 DOI: 10.1046/j.1525-1373.2000.22426.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
MHC-linked class-Ib molecules are a subfamily of class-I molecules that display limited genetic polymorphism. At one time these molecules were considered to have an enigmatic function. However, recent studies have shown that MHC-linked class-Ib molecules can function as antigen presentation structures that bind bacteria-derived epitopes for recognition by CD8+ effector T cells. This role for class-Ib molecules has been demonstrated across broad classes of intracellular bacteria including Listeria moncytogenes, Salmonella typhimurium, and Mycobacterium tuberculosis. Additionally, evidence is emerging that MHC-linked class-Ib molecules also serve an integral role as recognition elements for NK cells as well as several TCR alpha/beta and TCR gamma/delta T-cell subsets. Thus, MHC-linked class-Ib molecules contribute to the host immune response by serving as antigen presentation molecules and recognition ligands in both the innate and adaptive immune response to infection. In this review, we will attempt to summarize the work that supports a role for MHC-linked class-Ib molecules in the host response to infection with intracellular bacteria.
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Affiliation(s)
- M J Soloski
- Division of Rheumatology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
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132
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Gao GF, Willcox BE, Wyer JR, Boulter JM, O'Callaghan CA, Maenaka K, Stuart DI, Jones EY, Van Der Merwe PA, Bell JI, Jakobsen BK. Classical and nonclassical class I major histocompatibility complex molecules exhibit subtle conformational differences that affect binding to CD8alphaalpha. J Biol Chem 2000; 275:15232-8. [PMID: 10809759 DOI: 10.1074/jbc.275.20.15232] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The cell surface molecules CD4 and CD8 greatly enhance the sensitivity of T-cell antigen recognition, acting as "co-receptors" by binding to the same major histocompatibility complex (MHC) molecules as the T-cell receptor (TCR). Here we use surface plasmon resonance to study the binding of CD8alphaalpha to class I MHC molecules. CD8alphaalpha bound the classical MHC molecules HLA-A*0201, -A*1101, -B*3501, and -C*0702 with dissociation constants (K(d)) of 90-220 microm, a range of affinities distinctly lower than that of TCR/peptide-MHC interaction. We suggest such affinities apply to most CD8alphaalpha/classical class I MHC interactions and may be optimal for T-cell recognition. In contrast, CD8alphaalpha bound both HLA-A*6801 and B*4801 with a significantly lower affinity (>/=1 mm), consistent with the finding that interactions with these alleles are unable to mediate cell-cell adhesion. Interestingly, CD8alphaalpha bound normally to the nonclassical MHC molecule HLA-G (K(d) approximately 150 microm), but only weakly to the natural killer cell receptor ligand HLA-E (K(d) >/= 1 mm). Site-directed mutagenesis experiments revealed that variation in CD8alphaalpha binding affinity can be explained by amino acid differences within the alpha3 domain. Taken together with crystallographic studies, these results indicate that subtle conformational changes in the solvent exposed alpha3 domain loop (residues 223-229) can account for the differential ability of both classical and nonclassical class I MHC molecules to bind CD8.
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Affiliation(s)
- G F Gao
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, Cambridge, Massachusetts 02138, USA
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133
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Abstract
NK cells recognize several HLA class Ib molecules employing both immunoglobulin-like (Ig-like) and C-type lectin receptors. The CD94/NKG2 and NKG2D lectin-like molecules, respectively, interact with HLA-E and MICA; CD94/NKG2A functions as an inhibitory receptor, while CD94/NKG2C and NKG2D trigger NK cell activity. HLA-E predominantly presents nonamers from the leader sequences of other class I molecules; a peptide derived from HLA-G1 constitutes the highest affinity ligand for both CD94/NKG2 receptors. Members of the Ig-like transcript (ILT) or leucocyte Ig-like receptor (LIR) family (ILT2 or LIR-1 and ILT4 or LIR-2), expressed by other leucocyte lineages, interact with a broad spectrum of HLA class Ia molecules and HLA-G1. Among Ig-like KIRs, the KIR2DL4 (p49) receptor has been shown to specifically recognize HLA-G1; this molecule displays an unusual hybrid structure, sharing features with inhibitory and triggering KIRs.
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Affiliation(s)
- M López-Botet
- Servicio de Inmunología, Hospital Universitario de la Princesa, Diego de Léon 62, Madrid, 28006, Spain
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134
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O'Callaghan CA. Natural killer cell surveillance of intracellular antigen processing pathways mediated by recognition of HLA-E and Qa-1b by CD94/NKG2 receptors. Microbes Infect 2000; 2:371-80. [PMID: 10817639 DOI: 10.1016/s1286-4579(00)00330-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
HLA-E binds specifically to MHC class Ia leader peptides in a TAP (transporter associated with antigen processing)-dependent manner. It interacts with CD94/NKG2A receptors on natural killer cells and this inhibits natural killer cell lysis of the cell displaying HLA-E. The crystal structure of HLA-E demonstrates that the specificity of leader peptide binding is a structurally defined intrinsic property of HLA-E.
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Affiliation(s)
- C A O'Callaghan
- Nuffield Department of Medicine, Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, UK
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135
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Zappacosta F, Tabaczewski P, Parker KC, Coligan JE, Stroynowski I. The murine liver-specific nonclassical MHC class I molecule Q10 binds a classical peptide repertoire. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 164:1906-15. [PMID: 10657640 DOI: 10.4049/jimmunol.164.4.1906] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The biological properties of the nonclassical class I MHC molecules secreted into blood and tissue fluids are not currently understood. To address this issue, we studied the murine Q10 molecule, one of the most abundant, soluble class Ib molecules. Mass spectrometry analyses of hybrid Q10 polypeptides revealed that alpha1alpha2 domains of Q10 associate with 8-9 long peptides similar to the classical class I MHC ligands. Several of the sequenced peptides matched intracellularly synthesized murine proteins. This finding and the observation that the Q10 hybrid assembly is TAP2-dependent supports the notion that Q10 groove is loaded by the classical class I Ag presentation pathway. Peptides eluted from Q10 displayed a binding motif typical of H-2K, D, and L ligands. They carried conserved residues at P2 (Gly), P6 (Leu), and Pomega (Phe/Leu). The role of these residues as anchors/auxiliary anchors was confirmed by Ala substitution experiments. The Q10 peptide repertoire was heterogeneous, with 75% of the groove occupied by a multitude of diverse peptides; however, 25% of the molecules bound a single peptide identical to a region of a TCR V beta-chain. Since this peptide did not display enhanced binding affinity for Q10 nor does its origin and sequence suggest that it is functionally significant, we propose that the nonclassical class I groove of Q10 resembles H-2K, D, and L grooves more than the highly specialized clefts of nonclassical class I Ags such as Qa-1, HLA-E, and M3.
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Affiliation(s)
- F Zappacosta
- Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
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136
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López-Botet M, Bellón T, Llano M, Navarro F, García P, de Miguel M. Paired inhibitory and triggering NK cell receptors for HLA class I molecules. Hum Immunol 2000; 61:7-17. [PMID: 10658973 DOI: 10.1016/s0198-8859(99)00161-5] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Human natural killer (NK) cells specifically interact with major histocompatibility complex (MHC) class I molecules employing different receptor systems, shared with subsets of alphabeta and gammadelta T lymphocytes. Killer cell immunoglobulin-like receptors (KIRs) recognize groups of human leukocyte antigen (HLA) class Ia proteins displaying common structural features at the alpha-1 domain; among them, KIR2DL4 has been proposed to specifically interact with the class Ib molecule HLA-G1. Members of a related family of immunoglobulin (Ig)-like receptors (ILT2 or LIR-1 and ILT4 or LIR-2), expressed by other leukocyte lineages, interact with a broad spectrum of class Ia molecules and HLA-G1. On the other hand, CD94/NKG2-A(-C) and NKG2D lectin-like receptors, respectively, recognize the class Ib molecules HLA-E and MICA. A recurrent finding within the different receptor families is the existence of pairs of homologous molecules that often share the same ligands but display divergent functions. Inhibitory receptors tend to exhibit an affinity for HLA molecules higher than their activating counterparts. Recruitment of SH2 domain-bearing tyrosine phosphatases (SHP) by cytoplasmic phosphorylated immunoreceptor tyrosine-based inhibition motifs (ITIMs) is a crucial event for the inhibitory signalling pathway. By contrast, triggering receptors assemble with homodimers of immune tyrosine-based activation motif (ITAM)-bearing adaptor molecules (i.e., DAP12, CD3 xi) that engage tyrosine kinases (ZAP70 and syk).
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Affiliation(s)
- M López-Botet
- Servicio de Immunología, Hospital Universitario de la Princesa, Madrid, Spain.
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137
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Chiu NM, Wang B, Kerksiek KM, Kurlander R, Pamer EG, Wang CR. The selection of M3-restricted T cells is dependent on M3 expression and presentation of N-formylated peptides in the thymus. J Exp Med 1999; 190:1869-78. [PMID: 10601361 PMCID: PMC2195718 DOI: 10.1084/jem.190.12.1869] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/1999] [Accepted: 09/27/1999] [Indexed: 11/24/2022] Open
Abstract
The major histocompatibility complex (MHC) class Ib molecule H2-M3 binds N-formylated peptides from mitochondria and bacteria. To explore the role of M3 expression and peptide supply in positive and negative selection, we generated transgenic mice expressing an M3-restricted TCR-alpha/beta from a CD8(+) T cell hybridoma (D7) specific for a listerial peptide (LemA). Development of M3-restricted transgenic T cells is impaired in both beta2-microglobulin-deficient and transporter associated with antigen processing (TAP)-deficient mice, but is not diminished by changes in the H-2 haplotype. Maturation of M3/LemA-specific CD8(+) single positive cells in fetal thymic organ culture was sensitive to M3 expression levels as determined by antibody blocking and use of the castaneus mutant allele of M3. Positive selection was rescued in TAP(-/-) lobes by nonagonist mitochondrial and bacterial peptides, whereas LemA and a partial agonist variant caused negative selection. Thus, M3-restricted CD8(+) T cells are positively and negatively selected by M3, with no contribution from the more abundant class Ia molecules. These results demonstrate that class Ib molecules can function in thymic education like class Ia molecules, despite limited ligand diversity and low levels of expression.
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Affiliation(s)
- Nancy M. Chiu
- Gwen Knapp Center for Lupus and Immunology Research, Committee on Immunology and Department of Pathology, University of Chicago, Chicago, Illinois 60637
| | - Bin Wang
- Gwen Knapp Center for Lupus and Immunology Research, Committee on Immunology and Department of Pathology, University of Chicago, Chicago, Illinois 60637
| | - Kristen M. Kerksiek
- Section of Infectious Diseases, Yale University, New Haven, Connecticut 06520
- the Section of Immunobiology, Yale University, New Haven, Connecticut 06520
| | - Roger Kurlander
- Clinical Pathology Department, Clinical Center, National Institutes of Health, Bethesda, Maryland 20892-1508
| | - Eric G. Pamer
- Section of Infectious Diseases, Yale University, New Haven, Connecticut 06520
- the Section of Immunobiology, Yale University, New Haven, Connecticut 06520
| | - Chyung-Ru Wang
- Gwen Knapp Center for Lupus and Immunology Research, Committee on Immunology and Department of Pathology, University of Chicago, Chicago, Illinois 60637
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138
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Abstract
During the past year, a plethora of structural information has provided detailed insights into the interactions between classical MHC class I molecules and their cognate receptors on T cells. Likewise, there have been major advances in our knowledge of the structures and functions of five nonclassical MHC-like molecules: HLA-DM (murine H2-M), HLA-E, HFE, ZAG and MIC-A.
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Affiliation(s)
- K Maenaka
- Structural Biology, Wellcome Trust Centre for Human Genetics, Headington, OX3 7BN, UK.
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139
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Kronenberg M, Brossay L, Kurepa Z, Forman J. Conserved lipid and peptide presentation functions of nonclassical class I molecules. IMMUNOLOGY TODAY 1999; 20:515-21. [PMID: 10529780 DOI: 10.1016/s0167-5699(99)01521-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- M Kronenberg
- La Jolla Institute for Allergy and Immunology, 10355 Science Center Drive, San Diego, CA 92121, USA.
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140
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Petersson E, Holmdahl R, Butcher GW, Hedlund G. Activation and selection of NK cells via recognition of an allogeneic, non-classical MHC class I molecule, RT1-E. Eur J Immunol 1999; 29:3663-73. [PMID: 10556822 DOI: 10.1002/(sici)1521-4141(199911)29:11<3663::aid-immu3663>3.0.co;2-f] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Previous studies have established that NK cells express both inhibitory and activatory receptors. The inhibitory receptors have been shown to recognize major MHC class I molecules, but the physiological ligands for the activatory receptors have been only partly characterized. In this study we investigated whether NK cells could be activated by recognizing specific non-classical MHC class Ib molecules. NK cells from BN (RT1(n)) rats immunized in vivo with MHC-incompatible WF (RT1(u)) cells displayed cytolytic activity specific for product(s) of the MHC class Ib RT1-E(u) / C(u) region. These cells were shown to kill Rat2 fibroblast cells transfected with cDNA for RT1-E(u) but neither untransfected Rat2 nor a transfectant with the class Ia allele, RT1-A(u). Cytolysis of Rat2-RT1-E(u) was inhibited by the anti-RT1-E(u) antibody 70-3-C2. In addition, NK cells cytolytic against PVG (RT1(c)) targets, but not against WF (RT1(u)) or other allogeneic targets were activated after PVG immunization of BN rats. The generation of NK populations cytolytic for target cells of the same haplotype as the immunizing cells, but not for third-party targets, strongly suggests the existence of a selective NK-mediated response in vivo. We conclude that recognition of an allogeneic MHC class Ib RT1-E molecule activates NK cells and the specific cytolytic response could be regarded as adaptive.
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Affiliation(s)
- E Petersson
- Section of Tumor Immunology, Department of Cell and Molecular Biology, Lund University, Lund, Sweden.
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141
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Fan QR, Wiley DC. Structure of human histocompatibility leukocyte antigen (HLA)-Cw4, a ligand for the KIR2D natural killer cell inhibitory receptor. J Exp Med 1999; 190:113-23. [PMID: 10429675 PMCID: PMC2195553 DOI: 10.1084/jem.190.1.113] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
The crystal structure of the human class I major histocompatibility complex molecule, human histocompatibility leukocyte antigen (HLA)-Cw4, the ligand for a natural killer (NK) cell inhibitory receptor, has been determined, complexed with a nonameric consensus peptide (QYDDAVYKL). Relative to HLA-A2, the peptide binding groove is widened around the COOH terminus of the alpha 1 helix, which contains residues that determine the specificity of HLA-Cw4 for the inhibitory NK receptor, KIR2D. The structure reveals an unusual pattern of internal hydrogen bonding among peptide residues. The peptide is anchored in four specificity pockets in the cleft and secured by extensive hydrogen bonds between the peptide main chain and the cleft. The surface of HLA-Cw4 has electrostatic complementarity to the surface of the NK cell inhibitory receptor KIR2D.
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Affiliation(s)
- Q R Fan
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, Harvard University, Cambridge, Massachusetts 02138, USA
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142
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Navarro F, Llano M, García P, López-Botet M. NK cell mediated recognition of HLA class Ib molecules: role of CD94/NKG2 receptors. J Reprod Immunol 1999; 43:167-73. [PMID: 10479052 DOI: 10.1016/s0165-0378(99)00030-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- F Navarro
- Servicio De InmunologIa, Hospital Universitario De La Princesa, Madrid, Spain
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143
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Martinozzi S, Pacasova R, Boulouis HJ, Ulbrecht M, Weiss EH, Sigaux F, Pla M. Cutting Edge: Requirement of Class I Signal Sequence-Derived Peptides for HLA-E Recognition by a Mouse Cytotoxic T Cell Clone. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.162.10.5662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
The human nonclassical MHC class I molecule HLA-E has recently been shown to act as a major ligand for NK cell inhibitory receptors. Using HLA-E-expressing transgenic mice, we produced a cytotoxic T cell clone that specifically recognizes the HLA-E molecule. We report here that this T cell clone lyses HLA-E-transfected RMA-S target cells sensitized with synthetic class I signal sequence nonamers. Moreover, this T cell clone lyses human EBV-infected B lymphocytes, PHA blasts, and PBL, formally demonstrating the surface expression of HLA-E/class I signal-derived peptide complex on human cells. Furthermore, these data show that HLA-E complexed with class I signal sequence-derived peptides is not only a ligand for NK cell inhibitory receptors, but can also trigger cytotoxic T cells (CTL).
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Affiliation(s)
- Silvia Martinozzi
- * Mouse Immunogenetics, Institut National de la Santé et de la Recherche Médicale, Unite 462, Institute of Hematology, Hôpital Saint-Louis, Paris, France
| | - Rita Pacasova
- * Mouse Immunogenetics, Institut National de la Santé et de la Recherche Médicale, Unite 462, Institute of Hematology, Hôpital Saint-Louis, Paris, France
| | - Henri-Jean Boulouis
- * Mouse Immunogenetics, Institut National de la Santé et de la Recherche Médicale, Unite 462, Institute of Hematology, Hôpital Saint-Louis, Paris, France
| | - Matthias Ulbrecht
- † Institut für Anthropologie und Humangenetik, Ludwig Maximilians-Universität, Munich, Germany
| | - Elisabeth H. Weiss
- † Institut für Anthropologie und Humangenetik, Ludwig Maximilians-Universität, Munich, Germany
| | - François Sigaux
- * Mouse Immunogenetics, Institut National de la Santé et de la Recherche Médicale, Unite 462, Institute of Hematology, Hôpital Saint-Louis, Paris, France
| | - Marika Pla
- * Mouse Immunogenetics, Institut National de la Santé et de la Recherche Médicale, Unite 462, Institute of Hematology, Hôpital Saint-Louis, Paris, France
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144
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Pacasova R, Martinozzi S, Boulouis HJ, Ulbrecht M, Vieville JC, Sigaux F, Weiss EH, Pla M. Cell-Surface Expression and Alloantigenic Function of a Human Nonclassical Class I Molecule (HLA-E) in Transgenic Mice. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.162.9.5190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
We have introduced the gene (E*01033) encoding the heavy chain of the human nonclassical MHC class I Ag, HLA-E, into the mouse genome. Two founder mice carry a 21-kb fragment, the others bear an 8-kb fragment. Each of the founder mice was mated to mice of an already established C57BL/10 transgenic line expressing human β2-microglobulin (β2m). Cell surface HLA-E was detected on lymph node cells by flow cytometry only in the presence of endogenous human β2m. However, HLA-E-reactive mouse CTL (H-2-unrestricted) lysed efficiently the target cells originating from HLA-E transgenic mice without human β2m, showing that the HLA-E protein can be transported to the cell surface in the absence of human β2m, presumably by association with murine β2m. Rejection of skin grafts from HLA-E transgenic mice demonstrates that HLA-E behaves as a transplantation Ag in mice. HLA-E transgenic spleen cells are effective in stimulating an allogeneic CTL response in normal and human classical class I (HLA-B27) transgenic mice. Furthermore, results from split-well analysis indicate that the majority of the primary in vivo-induced CTL recognizes HLA-E as an intact molecule (H-2-unrestricted recognition) and not as an HLA-E-derived peptide presented by a mouse MHC molecule, although a small fraction (ranging from 4 to 21%) of the primary in vivo-induced CTL is able to recognize HLA-E in an H-2-restricted manner. Based on these observations, we conclude that HLA-E exhibits alloantigenic properties that are indistinguishable from classical HLA class I molecules when expressed in transgenic mice.
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Affiliation(s)
- Rita Pacasova
- *Mouse Immunogenetics, U462, Institut National de la Santé et de la Recherche Médicale, Institute of Hematology, Saint-Louis Hospital, Paris, France; and
| | - Silvia Martinozzi
- †Institut für Anthropologie und Humangenetik, Ludwig-Maximilians-Universität, Munich, Germany
| | - Henri-Jean Boulouis
- *Mouse Immunogenetics, U462, Institut National de la Santé et de la Recherche Médicale, Institute of Hematology, Saint-Louis Hospital, Paris, France; and
| | - Matthias Ulbrecht
- †Institut für Anthropologie und Humangenetik, Ludwig-Maximilians-Universität, Munich, Germany
| | - Jean-Claude Vieville
- *Mouse Immunogenetics, U462, Institut National de la Santé et de la Recherche Médicale, Institute of Hematology, Saint-Louis Hospital, Paris, France; and
| | - François Sigaux
- *Mouse Immunogenetics, U462, Institut National de la Santé et de la Recherche Médicale, Institute of Hematology, Saint-Louis Hospital, Paris, France; and
| | - Elisabeth H. Weiss
- †Institut für Anthropologie und Humangenetik, Ludwig-Maximilians-Universität, Munich, Germany
| | - Marika Pla
- *Mouse Immunogenetics, U462, Institut National de la Santé et de la Recherche Médicale, Institute of Hematology, Saint-Louis Hospital, Paris, France; and
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145
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Matsuo H, Corlett L, Hawke S, Nicolle M, Driscoll P, Deshpande S, Spack E, Willcox N. Distant interactions between dimorphisms in HLA-DR4 radically affect recognition of defined peptides by a specific T cell clone. Int Immunol 1999; 11:835-43. [PMID: 10330288 DOI: 10.1093/intimm/11.5.835] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Several isolated dimorphisms recur in many HLA class II alleles, but it is not clear whether they merely influence the binding of peptides locally or have more general effects on their recognition by T cells. For example, interchanges in HLA-DRbeta include 86Gly <--> Val and 57Asp <--> Ser at either end of its alpha helix, and 71Arg <--> Lys in the middle. In DR4, the existence of six subtypes differing by single substitutions at these sites enabled us to assess their functional effects--both in isolation and in their natural context--on peptide presentation to a specific T cell clone with unusually broad cross-restrictions. Unexpectedly, the restriction imposed by 86Val was much more severe in the context of 71Arg than 71Lys, but was also more readily overcome by reducing the bulk of the 'p1' peptide 'anchor' residue (149Trp --> Phe). Moreover, when there was also a distant 57Asp-->Ser substitution, compensating similarly for 86Val proved much more difficult. Thus 86Val and 57Ser in combination had far more drastic effects on peptide presentation than they did separately, when peptide binding was also largely unchanged. These and other interactions with position 71 together provide strong evidence that the configuration of the peptide-DR4 complex is critical for T cell recognition, which could be affected by subtle conformational influences on the p1-9 core of the peptide or on the alpha helix of DR4beta (between positions 86 and 57). Ideally, therefore, the effects of individual class II substitutions should be considered in their natural context rather than in isolation.
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Affiliation(s)
- H Matsuo
- Neurosciences Group, Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
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146
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Lo WF, Ong H, Metcalf ES, Soloski MJ. T Cell Responses to Gram-Negative Intracellular Bacterial Pathogens: A Role for CD8+ T Cells in Immunity to Salmonella Infection and the Involvement of MHC Class Ib Molecules. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.162.9.5398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Despite being a major group of intracellular pathogens, the role of class I-restricted T cells in the clearance of Gram-negative bacteria is not resolved. Using a murine typhoid model, a role for class I-restricted T cells in the immune response to the Gram-negative pathogen Salmonella typhimurium is revealed. Class I-deficient β2-microglobulin−/− mice show increased susceptibility to infection with S. typhimurium. Following infection, CD8+ CTLs specific for Salmonella-infected targets can be readily detected. The Salmonella-specific CTLs recognize infected H-2-mismatched targets, suggesting the involvement of shared class Ib molecules. Studies using transfectants expressing defined class Ia and class Ib molecules indicate the involvement of the class Ib molecule, Qa-1. Ab-blocking studies and the measurement of bacteria-specific CTL frequencies identified Qa-1 as a dominant restricting element. The Qa-1-restricted CTL recognition depends on TAP and proteasome functions. Surprisingly, Qa-1-restricted CTLs recognized cells infected with other closely related Gram-negative bacteria. Taken together, these observations indicate that Salmonella-specific CTLs recognize a cross-reactive epitope presented by Qa-1 molecules and, as such, may be novel targets for vaccine development.
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Affiliation(s)
- Wei-Feng Lo
- *Division of Molecular and Clinical Rheumatology, Department of Medicine, and Graduate Program in Immunology, Johns Hopkins University School of Medicine, Baltimore, MD 21205; and
| | - Helena Ong
- *Division of Molecular and Clinical Rheumatology, Department of Medicine, and Graduate Program in Immunology, Johns Hopkins University School of Medicine, Baltimore, MD 21205; and
| | - Eleanor S. Metcalf
- †Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814
| | - Mark J. Soloski
- *Division of Molecular and Clinical Rheumatology, Department of Medicine, and Graduate Program in Immunology, Johns Hopkins University School of Medicine, Baltimore, MD 21205; and
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147
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Abstract
T-lymphocytes recognize short peptide antigens bound stably to polymorphic major histocompatibility complex (MHC)-encoded glycoproteins expressed on the surface of antigen-presenting cells (APC). Two general pathways have evolved to generate peptide-MHC complexes. The MHC class II antigen processing pathway provides a mechanism for sampling proteins present in endosomal compartments. CD4+ regulatory T-cells recognize peptides bound to MHC class II molecules, which are selectively expressed in specialized APC that have efficient mechanisms for uptake of microbial antigens, and express costimulatory molecules required for activating naive T-cells. CD8+ T-cells recognize peptides bound to MHC class I molecules. Class I molecules are widely expressed and bind peptides derived from the normal turnover of cellular proteins, providing a mechanism to display a sampling of cellular components to be monitored for abnormalities by cytotoxic T-cells. Specialized accessory proteins influence the efficiency of antigen presentation and the specificity of immune responses through their roles in generating peptides, targeting antigen and MHC glycoproteins to selected intracellular compartments, and by direct participation in the peptide-loading mechanism. It has recently been discovered that some viruses have evolved ways to inhibit or subvert discrete steps in antigen processing, providing a mechanism to evade immune recognition.
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Affiliation(s)
- P E Jensen
- The Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
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148
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Braud VM, Allan DS, McMichael AJ. Functions of nonclassical MHC and non-MHC-encoded class I molecules. Curr Opin Immunol 1999; 11:100-8. [PMID: 10047540 DOI: 10.1016/s0952-7915(99)80018-1] [Citation(s) in RCA: 159] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Fascinating recent discoveries have focused attention on the nonclassical class I molecules. They can exert their function at most levels of the immune response, being part of both innate and adaptive immune systems. They not only have specialized antigen-presentation functions but also play important immunoregulatory roles: HLA-E regulates natural killer cells by interacting with CD94/NKG2 receptors; the MIC (MHC class I chain related) glycoproteins appear crucial to the activation of gammadelta T cells in the gastrointestinal epithelium; HLA-G may play a role in controlling the immune response to the fetus; and CD1 molecules are important in defense against bacterial infections, as well as in the development and regulation of a subset of NKT cells expressing a highly restricted TCR repertoire; however not all nonclassical class I molecules have an immunological function, as demonstrated by HFE which is implicated in iron metabolism.
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Affiliation(s)
- V M Braud
- Institute of Molecular Medicine, John Radcliffe Hospital, Oxford, UK.
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149
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Ulbrecht M, Couturier A, Martinozzi S, Pla M, Srivastava R, Peterson PA, Weiss EH. Cell surface expression of HLA-E: interaction with human beta2-microglobulin and allelic differences. Eur J Immunol 1999; 29:537-47. [PMID: 10064069 DOI: 10.1002/(sici)1521-4141(199902)29:02<537::aid-immu537>3.0.co;2-6] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The formation of a trimeric complex composed of MHC class I heavy chain, beta2-microglobulin (beta2m) and peptide ligand is a prerequisite for its efficient transport to the cell surface. We have previously demonstrated impaired intracellular transport of the human class Ib molecule HLA-E in mouse myeloma X63 cells cotransfected with the genes for HLA-E and human beta2m (hbeta2m), which is most likely attributable to inefficient intracellular peptide loading of the HLA-E molecule. Here we demonstrate that cell surface expression of HLA-E in mouse cells strictly depends on the coexpression of hbeta2m and that soluble empty complexes of HLA-E and hbeta2m display a low degree of thermostability. Both observations imply that low affinity interaction of HLA-E with beta2m accounts to a considerable extent for the observed low degree of peptide uptake in the endoplasmic reticulum. Moreover, we show that the only allelic variation present in the caucasoid population located at amino acid position 107 (Gly or Arg) greatly affects intracellular transport and cell surface expression upon transfection of the respective alleles into mouse cells. No obvious difference was found with regard to the sequence of the peptide ligand.
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Affiliation(s)
- M Ulbrecht
- Institut für Anthropologie und Humangenetik, Ludwig-Maximillians-Universität München, Germany
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150
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Leong LYW, Le Rolle AF, Deverson EV, Powis SJ, Larkins AP, Vaage JT, Stokland A, Lambracht-Washington D, Rolstad B, Joly E, Butcher GW. RT1-U: Identification of a Novel, Active, Class Ib Alloantigen of the Rat MHC. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.162.2.743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
In common with other mammalian species, the laboratory rat (Rattus norvegicus) expresses MHC class I molecules that have been categorized as either classical (class Ia) or nonclassical (class Ib). This distinction separates the class Ia molecules that play a conventional role in peptide Ag presentation to CD8 T cells from the others, whose function is unconventional or undefined. The class Ia molecules are encoded by the RT1-A region of the rat MHC, while the RT1-C/E/M region encodes up to 60 other class I genes or gene fragments, a number of which are known to be expressed (or to be expressible). Here we report upon novel MHC class Ib genes of the rat that we have expression cloned using new monoclonal alloantibodies and which we term RT1-U. The products detected by these Abs were readily identifiable by two-dimensional analysis of immunoprecipitates and were shown to be distinct from the class Ia products. Cellular studies of these molecules indicate that they function efficiently as targets for cytotoxic killing by appropriately raised polyclonal alloreactive CTL populations. The sequences of these class Ib genes group together in phylogenetic analysis, suggesting a unique locus or family. The combined serological, CTL, and sequence data all indicate that these products are genetically polymorphic.
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Affiliation(s)
- Louise Y. W. Leong
- *Department of Immunology, The Babraham Institute, Cambridge, United Kingdom
| | | | - Edward V. Deverson
- *Department of Immunology, The Babraham Institute, Cambridge, United Kingdom
| | - Simon J. Powis
- †Department of Biochemistry, University of Dundee, Dundee, United Kingdom
| | - Audrey P. Larkins
- *Department of Immunology, The Babraham Institute, Cambridge, United Kingdom
| | - John T. Vaage
- ‡Department of Anatomy, University of Oslo, Blindern, Norway; and
| | - Aasa Stokland
- ‡Department of Anatomy, University of Oslo, Blindern, Norway; and
| | | | - Bent Rolstad
- ‡Department of Anatomy, University of Oslo, Blindern, Norway; and
| | - Etienne Joly
- *Department of Immunology, The Babraham Institute, Cambridge, United Kingdom
| | - Geoffrey W. Butcher
- *Department of Immunology, The Babraham Institute, Cambridge, United Kingdom
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