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  1. Article: Mapping epitopes and antigenicity by site-directed masking.

    Paus, Didrik / Winter, Greg

    Proceedings of the National Academy of Sciences of the United States of America

    2006  Volume 103, Issue 24, Page(s) 9172–9177

    Abstract: Here we describe a method for mapping the binding of antibodies to the surface of a folded antigen. We first created a panel of mutant antigens (beta-lactamase) in which single surface-exposed residues were mutated to cysteine. We then chemically ... ...

    Abstract Here we describe a method for mapping the binding of antibodies to the surface of a folded antigen. We first created a panel of mutant antigens (beta-lactamase) in which single surface-exposed residues were mutated to cysteine. We then chemically tethered the cysteine residues to a solid phase, thereby masking a surface patch centered on each cysteine residue and blocking the binding of antibodies to this region of the surface. By these means we mapped the epitopes of several mAbs directed to beta-lactamase. Furthermore, by depleting samples of polyclonal antisera to the masked antigens and measuring the binding of each depleted sample of antisera to unmasked antigen, we mapped the antigenicity of 23 different epitopes. After immunization of mice and rabbits with beta-lactamase in Freund's adjuvant, we found that the antisera reacted with both native and denatured antigen and that the antibody response was mainly directed to an exposed and flexible loop region of the native antigen. By contrast, after immunization in PBS, we found that the antisera reacted only weakly with denatured antigen and that the antibody response was more evenly distributed over the antigenic surface. We suggest that denatured antigen (created during emulsification in Freund's adjuvant) elicits antibodies that bind mainly to the flexible regions of the native protein and that this explains the correlation between antigenicity and backbone flexibility. Denaturation of antigen during vaccination or natural infections would therefore be expected to focus the antibody response to the flexible loops.
    MeSH term(s) Animals ; Antibodies, Monoclonal/chemistry ; Antibodies, Monoclonal/immunology ; Antibody Specificity ; Antigens, Surface/chemistry ; Antigens, Surface/immunology ; Epitope Mapping/methods ; Freund's Adjuvant/metabolism ; Immunization/methods ; Mice ; Models, Molecular ; Mutation ; Protein Structure, Tertiary ; Rabbits ; beta-Lactamases/chemistry ; beta-Lactamases/immunology
    Chemical Substances Antibodies, Monoclonal ; Antigens, Surface ; Freund's Adjuvant (9007-81-2) ; beta-Lactamases (EC 3.5.2.6)
    Language English
    Publishing date 2006-06-05
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 209104-5
    ISSN 1091-6490 ; 0027-8424
    ISSN (online) 1091-6490
    ISSN 0027-8424
    DOI 10.1073/pnas.0600263103
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    In stock of ZB MED Cologne/Königswinter

    Zs.A 1148: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (1.OG)
    ab Jg. 2022: Lesesaal (EG)

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  2. Article: Visualizing the effects of antigen affinity on T-dependent B-cell differentiation.

    Brink, Robert / Phan, Tri Giang / Paus, Didrik / Chan, Tyani D

    Immunology and cell biology

    2007  Volume 86, Issue 1, Page(s) 31–39

    Abstract: Burnet's original description of the clonal selection hypothesis of antibody production included many prescient predictions of how 'lymphocytes carrying reactive sites' for foreign antigens might respond during immune responses. Somatic mutation, plasma ... ...

    Abstract Burnet's original description of the clonal selection hypothesis of antibody production included many prescient predictions of how 'lymphocytes carrying reactive sites' for foreign antigens might respond during immune responses. Somatic mutation, plasma cell differentiation and transition into memory cells were all described as potential fates for the 'variety of descendents' derived from proliferative expansion of antigen-reactive clones. After 50 years much is known about the molecular controls that drive these various processes. Comparatively little insight has been gained, however, into why particular daughter cells progress down one response pathway versus another. In this article, we briefly describe the evolution of the genetic technologies that now allow us to visualize the very processes predicted by Burnet. An in-depth description of the recently developed SW(HEL) mouse model and its utility for tracking in vivo B-cell responses to various forms of hen-egg lysozyme (HEL) is also provided. Recent data obtained with this system indicate that antigen-dependent variables play a critical role in regulating the differentiation of responding B cells into antibody-secreting plasma cells.
    MeSH term(s) Animals ; Antigen-Antibody Reactions ; B-Lymphocytes/immunology ; Cell Differentiation/immunology ; Flow Cytometry ; Immunoglobulins/immunology ; Lymphocyte Activation ; Lymphocyte Cooperation/immunology ; Mice ; Mice, Transgenic ; Muramidase/immunology ; Mutagenesis, Site-Directed ; Receptors, Antigen, B-Cell/immunology ; Receptors, Antigen, T-Cell/immunology ; Recombinant Proteins/immunology ; Self Tolerance/immunology ; T-Lymphocytes, Helper-Inducer/immunology
    Chemical Substances Immunoglobulins ; Receptors, Antigen, B-Cell ; Receptors, Antigen, T-Cell ; Recombinant Proteins ; hen egg lysozyme (EC 3.2.1.-) ; Muramidase (EC 3.2.1.17)
    Language English
    Publishing date 2007-11-20
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Review
    ZDB-ID 284057-1
    ISSN 1440-1711 ; 0818-9641
    ISSN (online) 1440-1711
    ISSN 0818-9641
    DOI 10.1038/sj.icb.7100143
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    Uc I Zs.175: Show issues Location:
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  3. Article ; Online: Guidance of B cells by the orphan G protein-coupled receptor EBI2 shapes humoral immune responses.

    Gatto, Dominique / Paus, Didrik / Basten, Antony / Mackay, Charles R / Brink, Robert

    Immunity

    2009  Volume 31, Issue 2, Page(s) 259–269

    Abstract: Humoral immunity depends on both rapid and long-term antibody production against invading pathogens. This is achieved by the generation of spatially distinct extrafollicular plasmablast and follicular germinal center (GC) B cell populations, but the ... ...

    Abstract Humoral immunity depends on both rapid and long-term antibody production against invading pathogens. This is achieved by the generation of spatially distinct extrafollicular plasmablast and follicular germinal center (GC) B cell populations, but the signals that guide responding B cells to these alternative compartments have not been fully elucidated. Here, we show that expression of the orphan G protein-coupled receptor Epstein-Barr virus-induced gene 2 (EBI2, also known as GPR183) by activated B cells was essential for their movement to extrafollicular sites and induction of early plasmablast responses. Conversely, downregulation of EBI2 enabled B cells to access the center of follicles and promoted efficient GC formation. EBI2 therefore provides a previously uncharacterized dimension to B cell migration that is crucial for coordinating rapid versus long-term antibody responses.
    MeSH term(s) Adoptive Transfer ; Animals ; Antibody Formation ; B-Lymphocytes/immunology ; B-Lymphocytes/metabolism ; Cell Movement/immunology ; Chemotaxis/immunology ; Cytokines/immunology ; Cytokines/metabolism ; Down-Regulation/genetics ; Down-Regulation/immunology ; Germinal Center/immunology ; Germinal Center/metabolism ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Mice, Transgenic ; Receptors, G-Protein-Coupled/genetics ; Receptors, G-Protein-Coupled/metabolism ; T-Lymphocytes/immunology ; T-Lymphocytes/metabolism
    Chemical Substances Cytokines ; Gpr183 protein, mouse ; Receptors, G-Protein-Coupled
    Language English
    Publishing date 2009-08-21
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 1217235-2
    ISSN 1097-4180 ; 1074-7613
    ISSN (online) 1097-4180
    ISSN 1074-7613
    DOI 10.1016/j.immuni.2009.06.016
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    Zs.A 4227: Show issues Location:
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    Zs.MG 69: Show issues

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  4. Article: Antigen recognition strength regulates the choice between extrafollicular plasma cell and germinal center B cell differentiation.

    Paus, Didrik / Phan, Tri Giang / Chan, Tyani D / Gardam, Sandra / Basten, Antony / Brink, Robert

    The Journal of experimental medicine

    2006  Volume 203, Issue 4, Page(s) 1081–1091

    Abstract: B cells responding to T-dependent antigen either differentiate rapidly into extrafollicular plasma cells or enter germinal centers and undergo somatic hypermutation and affinity maturation. However, the physiological cues that direct B cell ... ...

    Abstract B cells responding to T-dependent antigen either differentiate rapidly into extrafollicular plasma cells or enter germinal centers and undergo somatic hypermutation and affinity maturation. However, the physiological cues that direct B cell differentiation down one pathway versus the other are unknown. Here we show that the strength of the initial interaction between B cell receptor (BCR) and antigen is a primary determinant of this decision. B cells expressing a defined BCR specificity for hen egg lysozyme (HEL) were challenged with sheep red blood cell conjugates of a series of recombinant mutant HEL proteins engineered to bind this BCR over a 10,000-fold affinity range. Decreasing either initial BCR affinity or antigen density was found to selectively remove the extrafollicular plasma cell response but leave the germinal center response intact. Moreover, analysis of competing B cells revealed that high affinity specificities are more prevalent in the extrafollicular plasma cell versus the germinal center B cell response. Thus, the effectiveness of early T-dependent antibody responses is optimized by preferentially steering B cells reactive against either high affinity or abundant epitopes toward extrafollicular plasma cell differentiation. Conversely, responding clones with weaker antigen reactivity are primarily directed to germinal centers where they undergo affinity maturation.
    MeSH term(s) Animals ; Antigens, Differentiation, B-Lymphocyte/metabolism ; B-Lymphocytes/cytology ; B-Lymphocytes/immunology ; B-Lymphocytes/metabolism ; Cell Differentiation/immunology ; Cells, Cultured ; Germinal Center/cytology ; Germinal Center/immunology ; Germinal Center/metabolism ; Mice ; Mice, Inbred C57BL ; Plasma Cells/cytology ; Plasma Cells/immunology ; Plasma Cells/metabolism ; Receptors, Antigen, B-Cell/metabolism
    Chemical Substances Antigens, Differentiation, B-Lymphocyte ; Receptors, Antigen, B-Cell
    Language English
    Publishing date 2006-04-10
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 218343-2
    ISSN 1540-9538 ; 0022-1007
    ISSN (online) 1540-9538
    ISSN 0022-1007
    DOI 10.1084/jem.20060087
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    Ua VI Zs.107: Show issues Location:
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  5. Article: High affinity germinal center B cells are actively selected into the plasma cell compartment.

    Phan, Tri Giang / Paus, Didrik / Chan, Tyani D / Turner, Marian L / Nutt, Stephen L / Basten, Antony / Brink, Robert

    The Journal of experimental medicine

    2006  Volume 203, Issue 11, Page(s) 2419–2424

    Abstract: A hallmark of T cell-dependent immune responses is the progressive increase in the ability of serum antibodies to bind antigen and provide immune protection. Affinity maturation of the antibody response is thought to be connected with the preferential ... ...

    Abstract A hallmark of T cell-dependent immune responses is the progressive increase in the ability of serum antibodies to bind antigen and provide immune protection. Affinity maturation of the antibody response is thought to be connected with the preferential survival of germinal centre (GC) B cells that have acquired increased affinity for antigen via somatic hypermutation of their immunoglobulin genes. However, the mechanisms that drive affinity maturation remain obscure because of the difficulty in tracking the affinity-based selection of GC B cells and their differentiation into plasma cells. We describe a powerful new model that allows these processes to be followed as they occur in vivo. In contrast to evidence from in vitro systems, responding GC B cells do not undergo plasma cell differentiation stochastically. Rather, only GC B cells that have acquired high affinity for the immunizing antigen form plasma cells. Affinity maturation is therefore driven by a tightly controlled mechanism that ensures only antibodies with the greatest possibility of neutralizing foreign antigen are produced. Because the body can sustain only limited numbers of plasma cells, this "quality control" over plasma cell differentiation is likely critical for establishing effective humoral immunity.
    MeSH term(s) Amino Acid Substitution/genetics ; Animals ; B-Lymphocyte Subsets/cytology ; B-Lymphocyte Subsets/immunology ; Cell Differentiation/immunology ; Genes, Immunoglobulin ; Germinal Center/cytology ; Germinal Center/immunology ; Immunoglobulin Heavy Chains/genetics ; Mice ; Mice, Transgenic ; Plasma Cells/cytology ; Plasma Cells/immunology
    Chemical Substances Immunoglobulin Heavy Chains
    Language English
    Publishing date 2006-10-30
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 218343-2
    ISSN 1540-9538 ; 0022-1007
    ISSN (online) 1540-9538
    ISSN 0022-1007
    DOI 10.1084/jem.20061254
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    In stock of ZB MED Cologne/Königswinter

    Ua VI Zs.107: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 2021: Bestellungen von Artikeln über das Online-Bestellformular
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    Zs.MG 45: Show issues

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