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Khodoun MV, Morris SC, Shao WH, Potter C, Angerman E, Kiselev A, Yarawsky AE, Herr AB, Klausz K, Otte A, Peipp M, Finkelman FD. Suppression of IgE-mediated anaphylaxis and food allergy with monovalent anti-FcεRIα mAbs. J Allergy Clin Immunol 2021; 147:1838-1854.e4. [PMID: 33326804 PMCID: PMC8215870 DOI: 10.1016/j.jaci.2020.10.045] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 10/20/2020] [Accepted: 10/30/2020] [Indexed: 01/28/2023]
Abstract
BACKGROUND Mast cell and basophil activation by antigen cross-linking of FcεRI-bound IgE is central to allergy pathogenesis. We previously demonstrated global suppression of this process by rapid desensitization with anti-FcεRIα mAbs. OBJECTIVES We sought to determine whether use of monovalent (mv) anti-FcεRIα mAbs increases desensitization safety without loss of efficacy. METHODS mv anti-human (hu) FcεRIα mAbs were produced with mouse-derived immunoglobulin variable regions and huIgG1 or huIgG4 C regions and were used to suppress murine IgE-mediated anaphylaxis and food allergy. mAbs were administered as a single dose or as serially increasing doses to mice that express hu instead of mouse FcεRIα; mice that additionally have an allergy-promoting IL-4Rα mutation; and hu cord blood-reconstituted immunodeficient, hu cytokine-secreting, mice that have large numbers of activated hu mast cells. Anaphylaxis susceptibility was sometimes increased by treatment with IL-4 or a β-adrenergic receptor antagonist. RESULTS mv anti-hu FcεRIα mAbs are considerably less able than divalent mAbs are to induce anaphylaxis and deplete mast cell and basophil IgE, but mv mAbs still strongly suppress IgE-mediated disease. The mv mAbs can be safely administered as a single large dose to mice with typical susceptibility to anaphylaxis, while a rapid desensitization approach safely suppresses disease in mice with increased susceptibility. Our huIgG4 variant of mv anti-huFcεRIα mAb is safer than our huIgG1 variant is, apparently because reduced interactions with FcεRs decrease ability to indirectly cross-link FcεRI. CONCLUSIONS mv anti-FcεRIα mAbs more safely suppress IgE-mediated anaphylaxis and food allergy than divalent variants of the same mAbs do. These mv mAbs may be useful for suppression of huIgE-mediated disease.
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Affiliation(s)
- Marat V Khodoun
- Division of Allergy, Immunology and Rheumatology, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Suzanne C Morris
- Division of Allergy, Immunology and Rheumatology, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Wen-Hai Shao
- Division of Allergy, Immunology and Rheumatology, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Crystal Potter
- Division of Allergy, Immunology and Rheumatology, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Elizabeth Angerman
- Division of Immunobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Artem Kiselev
- Institute of Cytology, Russian Academy of Sciences, Saint Petersburg, Russia
| | - Alexander E Yarawsky
- Division of Immunobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Andrew B Herr
- Division of Immunobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio; Division of Infectious Diseases, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Katja Klausz
- Division of Stem Cell Transplantation and Immunotherapy, University Hospital Schleswig-Holstein, University of Kiel, Kiel, Germany
| | - Anna Otte
- Division of Stem Cell Transplantation and Immunotherapy, University Hospital Schleswig-Holstein, University of Kiel, Kiel, Germany
| | - Matthias Peipp
- Division of Stem Cell Transplantation and Immunotherapy, University Hospital Schleswig-Holstein, University of Kiel, Kiel, Germany
| | - Fred D Finkelman
- Division of Allergy, Immunology and Rheumatology, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio; Division of Immunobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.
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2
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Franks SE, Cambier JC. Putting on the Brakes: Regulatory Kinases and Phosphatases Maintaining B Cell Anergy. Front Immunol 2018; 9:665. [PMID: 29681901 PMCID: PMC5897502 DOI: 10.3389/fimmu.2018.00665] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 03/19/2018] [Indexed: 12/21/2022] Open
Abstract
B cell antigen receptor (BCR) signaling is a tightly regulated process governed by both positive and negative mediators/regulators to ensure appropriate responses to exogenous and autologous antigens. Upon naïve B cell recognition of antigen CD79 [the immunoreceptor tyrosine-based activation motif (ITAM)-containing signaling subunit of the BCR] is phosphorylated and recruits Src and Syk family kinases that then phosphorylate proximal intermediaries linked to downstream activating signaling circuitry. This plasma membrane localized signalosome activates PI3K leading to generation of PIP3 critical for membrane localization and activation of plecktrin homology domain-containing effectors. Conversely, in anergic B cells, chronic antigen stimulation drives biased monophosphorylation of CD79 ITAMs leading to recruitment of Lyn, but not Syk, which docks only to bi-phosphorylated ITAMS. In this context, Lyn appears to function primarily as a driver of inhibitory signaling pathways promoting the inhibition of the PI3K pathway by inositol phosphatases, SHIP-1 and PTEN, which hydrolyze PIP3 to PIP2. Lyn may also exert negative regulation of signaling through recruitment of SHP-1, a tyrosine phosphatase that dephosphorylates activating signaling molecules. Alleles of genes that encode or regulate expression of components of this axis, including SHIP-1, SHP-1, Csk/PTPn22, and Lyn, have been shown to confer risk of autoimmunity. This review will discuss functional interplay of components of this pathway and the impact of risk alleles on its function.
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Affiliation(s)
- S Elizabeth Franks
- Department of Immunology and Microbiology, University of Colorado Denver School of Medicine, Aurora, CO, United States
| | - John C Cambier
- Department of Immunology and Microbiology, University of Colorado Denver School of Medicine, Aurora, CO, United States
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Slupsky JR. Does B cell receptor signaling in chronic lymphocytic leukaemia cells differ from that in other B cell types? SCIENTIFICA 2014; 2014:208928. [PMID: 25101192 PMCID: PMC4102070 DOI: 10.1155/2014/208928] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 06/02/2014] [Indexed: 06/03/2023]
Abstract
Chronic lymphocytic leukaemia (CLL) is an incurable malignancy of mature B cells. CLL is important clinically in Western countries because of its commonality and because of the significant morbidity and mortality associated with the progressive form of this incurable disease. The B cell receptor (BCR) expressed on the malignant cells in CLL contributes to disease pathogenesis by providing signals for survival and proliferation, and the signal transduction pathway initiated by engagement of this receptor is now the target of several therapeutic strategies. The purpose of this review is to outline current understanding of the BCR signal cascade in normal B cells and then question whether this understanding applies to CLL cells. In particular, this review studies the phenomenon of anergy in CLL cells, and whether certain adaptations allow the cells to overcome anergy and allow full BCR signaling to take place. Finally, this review analyzes how BCR signals can be therapeutically targeted for the treatment of CLL.
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Affiliation(s)
- Joseph R. Slupsky
- Department of Molecular and Clinical Cancer Medicine, University of Liverpool, 6th Floor, Duncan Building, Daulby Street, Liverpool L69 3GA, UK
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4
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Aviszus K, Macleod MKL, Kirchenbaum GA, Detanico TO, Heiser RA, St Clair JB, Guo W, Wysocki LJ. Antigen-specific suppression of humoral immunity by anergic Ars/A1 B cells. THE JOURNAL OF IMMUNOLOGY 2012; 189:4275-83. [PMID: 23008448 DOI: 10.4049/jimmunol.1201818] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Autoreactive anergic B lymphocytes are considered to be dangerous because of their potential for activation and recruitment into autoimmune responses. However, they persist for days and constitute ∼5% of the B cell pool. We assessed their functional potential in the Ars/A1 transgene model, where anergic B cells express a dual-reactive Ag receptor that binds, in addition to a self-Ag, the hapten p-azophenylarsonate (Ars). When Ars/A1 B cells were transferred into adoptive recipients that were immunized with foreign proteins covalently conjugated with Ars, endogenous IgG immune responses to both were selectively and severely diminished, and the development of T helper cells was impaired. Approximately 95% inhibition of the anti-Ars response was attained with ∼4000 transferred Ars/A1 B cells through redundant mechanisms, one of which depended on their expression of MHC class II but not upon secretion of IL-10 or IgM. This Ag-specific suppressive activity implicates the autoreactive anergic B cell as an enforcer of immunological tolerance to self-Ags.
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Affiliation(s)
- Katja Aviszus
- Integrated Department of Immunology, National Jewish Health and University of Colorado School of Medicine, Denver, CO 80206, USA
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5
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Liubchenko GA, Appleberry HC, Holers VM, Banda NK, Willis VC, Lyubchenko T. Potentially autoreactive naturally occurring transitional T3 B lymphocytes exhibit a unique signaling profile. J Autoimmun 2012; 38:293-303. [PMID: 22365785 DOI: 10.1016/j.jaut.2011.12.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2011] [Revised: 11/23/2011] [Accepted: 12/08/2011] [Indexed: 12/01/2022]
Abstract
B lymphocytes exhibit phenotypic differences that correlate with their developmental or functional stages and affect humoral immune responses. One recently described subset of naturally occurring immature transitional type 3 (T3) B lymphocytes is believed to consist of potentially autoimmune cells whose signaling properties have not been studied in detail. This study characterizes intracellular signaling in T3 B cells in wildtype C57BL/6 mice. Protein phosphorylation and Ca(2+) responses upon B-cell antigen receptor (BCR) engagement were measured by multicolor flow cytometry. We observed high baseline signaling activity and reduced BCR-mediated responses in T3 cells, which confirmed their anergy - a functional state in which lymphocytes recognize chronically present self-antigens but cannot produce immune response due to intrinsic signaling inhibition. Our results also revealed a previously unknown T3-specific phosphorylation pattern of 24 key signaling molecules involved in BCR signal transduction. These characteristics reflect the balance between stimulatory and inhibitory BCR signaling pathways in anergy. Results obtained in the collagen-induced arthritis model demonstrate the loss of anergy in T3 B cells during the onset of the disease. Our findings provide rationale for further investigating alterations in B-cell signaling patterns as earliest functional biomarkers of changes in the immune tolerance of autoreactive B cells.
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Affiliation(s)
- Ganna A Liubchenko
- Division of Rheumatology, University of Colorado Denver School of Medicine, Mail Stop B115, 1775 Aurora Ct., Aurora, CO 80045, USA
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6
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O'Neill SK, Getahun A, Gauld SB, Merrell KT, Tamir I, Smith MJ, Dal Porto JM, Li QZ, Cambier JC. Monophosphorylation of CD79a and CD79b ITAM motifs initiates a SHIP-1 phosphatase-mediated inhibitory signaling cascade required for B cell anergy. Immunity 2011; 35:746-56. [PMID: 22078222 DOI: 10.1016/j.immuni.2011.10.011] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Revised: 08/16/2011] [Accepted: 10/13/2011] [Indexed: 12/17/2022]
Abstract
Anergic B cells are characterized by impaired signaling and activation after aggregation of their antigen receptors (BCR). The molecular basis of this impairment is not understood. In studies reported here, Src homology-2 (SH2)-containing inositol 5-phosphatase SHIP-1 and its adaptor Dok-1 were found to be constitutively phosphorylated in anergic B cells, and activation of this inhibitory circuit was dependent on Src-family kinase activity and consequent to biased BCR immunoreceptor tyrosine-based activation motif (ITAM) monophosphorylation. B cell-targeted deletion of SHIP-1 caused severe lupus-like disease. Moreover, absence of SHIP-1 in B cells led to loss of anergy as indicated by restoration of BCR signaling, loss of anergic surface phenotype, and production of autoantibodies. Thus, chronic BCR signals maintain anergy in part via ITAM monophosphorylation-directed activation of an inhibitory signaling circuit involving SHIP-1 and Dok-1.
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Affiliation(s)
- Shannon K O'Neill
- Integrated Department of Immunology, University of Colorado School of Medicine and National Jewish Health, Denver, CO 80206, USA
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7
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Busman-Sahay K, Sargent E, Harton JA, Drake JR. The Ia.2 epitope defines a subset of lipid raft-resident MHC class II molecules crucial to effective antigen presentation. THE JOURNAL OF IMMUNOLOGY 2011; 186:6710-7. [PMID: 21543648 DOI: 10.4049/jimmunol.1100336] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Previous work established that binding of the 11-5.2 anti-I-A(k) mAb, which recognizes the Ia.2 epitope on I-A(k) class II molecules, elicits MHC class II signaling, whereas binding of two other anti-I-A(k) mAbs that recognize the Ia.17 epitope fail to elicit signaling. Using a biochemical approach, we establish that the Ia.2 epitope recognized by the widely used 11-5.2 mAb defines a subset of cell surface I-A(k) molecules predominantly found within membrane lipid rafts. Functional studies demonstrate that the Ia.2-bearing subset of I-A(k) class II molecules is critically necessary for effective B cell-T cell interactions, especially at low Ag doses, a finding consistent with published studies on the role of raft-resident class II molecules in CD4 T cell activation. Interestingly, B cells expressing recombinant I-A(k) class II molecules possessing a β-chain-tethered hen egg lysosome peptide lack the Ia.2 epitope and fail to partition into lipid rafts. Moreover, cells expressing Ia.2(-) tethered peptide-class II molecules are severely impaired in their ability to present both tethered peptide or peptide derived from exogenous Ag to CD4 T cells. These results establish the Ia.2 epitope as defining a lipid raft-resident MHC class II conformer vital to the initiation of MHC class II-restricted B cell-T cell interactions.
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Affiliation(s)
- Kathleen Busman-Sahay
- Center for Immunology and Microbial Disease, Albany Medical College, Albany, NY 12208, USA
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8
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Abstract
A byproduct of the largely stochastic generation of a diverse B-cell specificity repertoire is production of cells that recognize autoantigens. Indeed, recent studies indicate that more than half of the primary repertoire consists of autoreactive B cells that must be silenced to prevent autoimmunity. While this silencing can occur by multiple mechanisms, it appears that most autoreactive B cells are silenced by anergy, wherein they populate peripheral lymphoid organs and continue to express unoccupied antigen receptors yet are unresponsive to antigen stimulation. Here we review molecular mechanisms that appear operative in maintaining the antigen unresponsiveness of anergic B cells. In addition, we present new data indicating that the failure of anergic B cells to mobilize calcium in response to antigen stimulation is not mediated by inactivation of stromal interacting molecule 1, a critical intermediary in intracellular store depletion-induced calcium influx.
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Affiliation(s)
- Yuval Yarkoni
- Integrated Department of Immunology, University of Colorado School of Medicine and National Jewish Health, Denver, CO, USA
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9
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Sigalov AB. The SCHOOL of nature: I. Transmembrane signaling. SELF/NONSELF 2010; 1:4-39. [PMID: 21559175 PMCID: PMC3091606 DOI: 10.4161/self.1.1.10832] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2009] [Revised: 11/30/2009] [Accepted: 12/01/2009] [Indexed: 11/19/2022]
Abstract
Receptor-mediated transmembrane signaling plays an important role in health and disease. Recent significant advances in our understanding of the molecular mechanisms linking ligand binding to receptor activation revealed previously unrecognized striking similarities in the basic structural principles of function of numerous cell surface receptors. In this work, I demonstrate that the Signaling Chain Homooligomerization (SCHOOL)-based mechanism represents a general biological mechanism of transmembrane signal transduction mediated by a variety of functionally unrelated single- and multichain activating receptors. within the SCHOOL platform, ligand binding-induced receptor clustering is translated across the membrane into protein oligomerization in cytoplasmic milieu. This platform resolves a long-standing puzzle in transmembrane signal transduction and reveals the major driving forces coupling recognition and activation functions at the level of protein-protein interactions-biochemical processes that can be influenced and controlled. The basic principles of transmembrane signaling learned from the SCHOOL model can be used in different fields of immunology, virology, molecular and cell biology and others to describe, explain and predict various phenomena and processes mediated by a variety of functionally diverse and unrelated receptors. Beyond providing novel perspectives for fundamental research, the platform opens new avenues for drug discovery and development.
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Affiliation(s)
- Alexander B Sigalov
- Department of Pathology; University of Massachusetts Medical School; Worcester, MA USA
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10
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Tanaka T, Ichimura K, Sato Y, Takata K, Morito T, Tamura M, Kondo E, Ohara N, Yanai H, Sakai M, Takahashi S, Yoshino T. Frequent downregulation or loss of CD79a expression in plasma cell myelomas: Potential clue for diagnosis. Pathol Int 2009; 59:804-8. [DOI: 10.1111/j.1440-1827.2009.02448.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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11
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Preissler MT, Kaiser L, Drake JR, Gosselin EJ. Low-Level Signaling Generated by FcγRIIB-B Cell Receptor Co-Ligation Establishes a State of Global B Cell Receptor Nonresponsiveness. Immunol Invest 2009. [DOI: 10.1081/imm-47385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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12
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Duty JA, Szodoray P, Zheng NY, Koelsch KA, Zhang Q, Swiatkowski M, Mathias M, Garman L, Helms C, Nakken B, Smith K, Farris AD, Wilson PC. Functional anergy in a subpopulation of naive B cells from healthy humans that express autoreactive immunoglobulin receptors. ACTA ACUST UNITED AC 2008; 206:139-51. [PMID: 19103878 PMCID: PMC2626668 DOI: 10.1084/jem.20080611] [Citation(s) in RCA: 172] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Self-reactive B cells not controlled by receptor editing or clonal deletion may become anergic. We report that fully mature human B cells negative for surface IgM and retaining only IgD are autoreactive and functionally attenuated (referred to as naive IgD+IgM− B cells [BND]). These BND cells typically make up 2.5% of B cells in the peripheral blood, have antibody variable region genes in germline (unmutated) configuration, and, by all current measures, are fully mature. Analysis of 95 recombinant antibodies expressed from the variable genes of single BND cells demonstrated that they are predominantly autoreactive, binding to HEp-2 cell antigens and DNA. Upon B cell receptor cross-linkage, BND cells have a reduced capacity to mobilize intracellular calcium or phosphorylate tyrosines, demonstrating that they are anergic. However, intense stimulation causes BND cells to fully respond, suggesting that these cells could be the precursors of autoantibody secreting plasma cells in autoimmune diseases such as systemic lupus erythematosus or rheumatoid arthritis. This is the first identification of a distinct mature human B cell subset that is naturally autoreactive and controlled by the tolerizing mechanism of functional anergy.
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Affiliation(s)
- J Andrew Duty
- Immunobiology and Cancer, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
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13
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Signaling Chain Homooligomerization (SCHOOL) Model. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2008; 640:121-63. [DOI: 10.1007/978-0-387-09789-3_12] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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14
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Polyak MJ, Li H, Shariat N, Deans JP. CD20 homo-oligomers physically associate with the B cell antigen receptor. Dissociation upon receptor engagement and recruitment of phosphoproteins and calmodulin-binding proteins. J Biol Chem 2008; 283:18545-52. [PMID: 18474602 DOI: 10.1074/jbc.m800784200] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
B cell antigen receptor (BCR) signaling initiates sustained cellular calcium influx necessary for the development, differentiation, and activation of B lymphocytes. CD20 is a B cell-restricted tetraspanning protein organized in the plasma membrane as multimeric molecular complexes involved in BCR-activated calcium entry. Using coprecipitation of native CD20 with tagged or truncated forms of the molecule, we provide here direct evidence of CD20 homo-oligomerization into tetramers. Additionally, the function of CD20 was explored by examining its association with surface-labeled and intracellular proteins before and after BCR signaling. Two major surface-labeled proteins that coprecipitated with CD20 were identified as the heavy and light chains of cell surface IgM, the antigen-binding components of the BCR. After activation, BCR-CD20 complexes dissociated, and phosphoproteins and calmodulin-binding proteins were transiently recruited to CD20. These data provide new evidence of the involvement of CD20 in signaling downstream of the BCR and, together with the previously described involvement of CD20 in calcium influx, the first evidence of physical coupling of the BCR to a calcium entry pathway.
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Affiliation(s)
- Maria J Polyak
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada
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15
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Cambier JC, Gauld SB, Merrell KT, Vilen BJ. B-cell anergy: from transgenic models to naturally occurring anergic B cells? Nat Rev Immunol 2007; 7:633-43. [PMID: 17641666 PMCID: PMC3714009 DOI: 10.1038/nri2133] [Citation(s) in RCA: 259] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Anergy, a condition in which cells persist in the periphery but are unresponsive to antigen, is responsible for silencing many self-reactive B cells. Loss of anergy is known to contribute to the development of autoimmune diseases, including systemic lupus erythematosus and type 1 diabetes. Multiple transgenic mouse models have enabled the dissection of mechanisms that underlie anergy, and recently, anergic B cells have been identified in the periphery of wild-type mice. Heterogeneity of mechanistic concepts developed using model systems has complicated our understanding of anergy and its biological features. In this Review, we compare and contrast the salient features of anergic B cells with a view to developing unifying mechanistic hypotheses that explain their lifestyles.
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Affiliation(s)
- John C Cambier
- Department of Immunology, University of Colorado Health Science Center and National Jewish Medical Research Center, 1400 Jackson Street, Denver, Colorado 80206, USA.
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16
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Kitaura Y, Jang IK, Wang Y, Han YC, Inazu T, Cadera EJ, Schlissel M, Hardy RR, Gu H. Control of the B cell-intrinsic tolerance programs by ubiquitin ligases Cbl and Cbl-b. Immunity 2007; 26:567-78. [PMID: 17493844 PMCID: PMC1948079 DOI: 10.1016/j.immuni.2007.03.015] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2006] [Revised: 01/04/2007] [Accepted: 03/29/2007] [Indexed: 01/13/2023]
Abstract
B cell receptor (BCR) signaling plays a critical role in B cell tolerance and activation. Here, we show that mice with B cell-specific ablation of both Cbl and Cbl-b (Cbl-/-Cblb-/-) manifested systemic lupus erythematosus (SLE)-like autoimmune disease. The Cbl double deficiency resulted in a substantial increase in marginal zone (MZ) and B1 B cells. The mutant B cells were not hyperresponsive in terms of proliferation and antibody production upon BCR stimulation; however, B cell anergy to protein antigen appeared to be impaired. Concomitantly, BCR-proximal signaling, including tyrosine phosphorylation of Syk tyrosine kinase, Phospholipase C-gamma2 (PLC-gamma2), and Rho-family GTP-GDP exchange factor Vav, and Ca2+ mobilization were enhanced, whereas tyrosine phosphorylation of adaptor protein BLNK was substantially attenuated in the mutant B cells. These results suggested that the loss of coordination between these pathways was responsible for the impaired B cell tolerance induction. Thus, Cbl proteins control B cell-intrinsic checkpoint of immune tolerance, possibly through coordinating multiple BCR-proximal signaling pathways during anergy induction.
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Affiliation(s)
- Yasuyuki Kitaura
- Department of Microbiology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
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17
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Abstract
Signalling through the B cell antigen receptor (BCR) is required for peripheral B lymphocyte maturation, maintenance, activation and silencing. In mature B cells, the antigen receptor normally consists of two isotypes, membrane IgM and IgD (mIgM, mIgD). Although the signals initiated from both isotypes differ in kinetics and intensity, in vivo, the BCR of either isotype seems to be able to compensate for the loss of the other, reflected by the mild phenotypes of mice deficient for mIgM or mIgD. Thus, it is still unclear why mature B cells need expression of mIgD in addition to mIgM. In the current review we suggest that the view that IgD has a simply definable function centred around the basic signalling function should be replaced by the assumption that IgD fine tunes humoral responses, modulates B cell selection and homeostasis and thus shapes the B cell repertoire, defining IgD to be a key modulator of the humoral immune response.
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Affiliation(s)
- Roland Geisberger
- University of Salzburg, Department of Molecular Biology, Salzburg, Austria
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18
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Hou P, Araujo E, Zhao T, Zhang M, Massenburg D, Veselits M, Doyle C, Dinner AR, Clark MR. B cell antigen receptor signaling and internalization are mutually exclusive events. PLoS Biol 2006; 4:e200. [PMID: 16719564 PMCID: PMC1470458 DOI: 10.1371/journal.pbio.0040200] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2005] [Accepted: 04/13/2006] [Indexed: 02/03/2023] Open
Abstract
Engagement of the B cell antigen receptor initiates two concurrent processes, signaling and receptor internalization. While both are required for normal humoral immune responses, the relationship between these two processes is unknown. Herein, we demonstrate that following receptor ligation, a small subpopulation of B cell antigen receptors are inductively phosphorylated and selectively retained at the cell surface where they can serve as scaffolds for the assembly of signaling molecules. In contrast, the larger population of non-phosphorylated receptors is rapidly endocytosed. Each receptor can undergo only one of two mutually exclusive fates because the tyrosine-based motifs that mediate signaling when phosphorylated mediate internalization when not phosphorylated. Mathematical modeling indicates that the observed competition between receptor phosphorylation and internalization enhances signaling responses to low avidity ligands.
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Affiliation(s)
- Ping Hou
- 1Department of Medicine and Section of Rheumatology, University of Chicago, Chicago, Illinois, United States of America
- 2Committee on Immunology, University of Chicago, Chicago, Illinois, United States of America
| | - Elizabeth Araujo
- 1Department of Medicine and Section of Rheumatology, University of Chicago, Chicago, Illinois, United States of America
- 2Committee on Immunology, University of Chicago, Chicago, Illinois, United States of America
| | - Tong Zhao
- 3Department of Chemistry, University of Chicago, Chicago, Illinois, United States of America
- 4Institute for Biophysical Dynamics, University of Chicago, Chicago, Illinois, United States of America
- 5James Franck Institute, University of Chicago, Chicago, Illinois, United States of America
| | - Miao Zhang
- 1Department of Medicine and Section of Rheumatology, University of Chicago, Chicago, Illinois, United States of America
| | - Don Massenburg
- 1Department of Medicine and Section of Rheumatology, University of Chicago, Chicago, Illinois, United States of America
- 2Committee on Immunology, University of Chicago, Chicago, Illinois, United States of America
| | - Margaret Veselits
- 1Department of Medicine and Section of Rheumatology, University of Chicago, Chicago, Illinois, United States of America
- 2Committee on Immunology, University of Chicago, Chicago, Illinois, United States of America
| | - Colleen Doyle
- 2Committee on Immunology, University of Chicago, Chicago, Illinois, United States of America
| | - Aaron R Dinner
- 2Committee on Immunology, University of Chicago, Chicago, Illinois, United States of America
- 3Department of Chemistry, University of Chicago, Chicago, Illinois, United States of America
- 4Institute for Biophysical Dynamics, University of Chicago, Chicago, Illinois, United States of America
- 5James Franck Institute, University of Chicago, Chicago, Illinois, United States of America
| | - Marcus R Clark
- 1Department of Medicine and Section of Rheumatology, University of Chicago, Chicago, Illinois, United States of America
- 2Committee on Immunology, University of Chicago, Chicago, Illinois, United States of America
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19
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Bléry M, Tze L, Miosge LA, Jun JE, Goodnow CC. Essential role of membrane cholesterol in accelerated BCR internalization and uncoupling from NF-kappa B in B cell clonal anergy. ACTA ACUST UNITED AC 2006; 203:1773-83. [PMID: 16801401 PMCID: PMC2118358 DOI: 10.1084/jem.20060552] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Divergent hypotheses exist to explain how signaling by the B cell receptor (BCR) is initiated after antigen binding and how it is qualitatively altered in anergic B cells to selectively uncouple from nuclear factor kappaB and c-Jun N-terminal kinase pathways while continuing to activate extracellular signal-regulated kinase and calcium-nuclear factor of activated T cell pathways. Here we find that BCRs on anergic cells are endocytosed at a very enhanced rate upon binding antigen, resulting in a large steady-state pool of intracellularly sequestered receptors that appear to be continuously cycling between surface and intracellular compartments. This endocytic mechanism is exquisitely sensitive to the lowering of plasma membrane cholesterol by methyl-beta-cyclodextrin, and, when blocked in this way, the sequestered BCRs return to the cell surface and RelA nuclear accumulation is stimulated. In contrast, when plasma membrane cholesterol is lowered and GM1 sphingolipid markers of membrane rafts are depleted in naive B cells, this does not diminish BCR signaling to calcium or RelA. These results provide a possible explanation for the signaling changes in clonal anergy and indicate that a chief function of membrane cholesterol in B cells is not to initiate BCR signaling, but instead to terminate a subset of signals by rapid receptor internalization.
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Affiliation(s)
- Mathieu Bléry
- John Curtin School of Medical Research, The Australian National University, Canberra ACT 2601, Australia
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20
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Tolar P, Sohn HW, Pierce SK. The initiation of antigen-induced B cell antigen receptor signaling viewed in living cells by fluorescence resonance energy transfer. Nat Immunol 2005; 6:1168-76. [PMID: 16200067 DOI: 10.1038/ni1262] [Citation(s) in RCA: 184] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2005] [Accepted: 09/12/2005] [Indexed: 11/09/2022]
Abstract
Binding of antigen to the B cell antigen receptor (BCR) triggers signaling that ultimately leads to B cell activation. Using quantitative fluorescence resonance energy transfer imaging, we provide evidence here that the BCR is a monomer on the surface of resting cells. Binding of multivalent antigen clustered the BCR, resulting in the simultaneous phosphorylation of and a conformational change in the BCR cytoplasmic domains from a closed to an open form. Notably, the open conformation required immunoreceptor tyrosine-activation motif and continuous Src family kinase activity but not binding of the kinase Syk. Thus, the initiation of BCR signaling is a very dynamic process accompanied by reversible conformational changes induced by Src family kinase activity.
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Affiliation(s)
- Pavel Tolar
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland 20852, USA
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21
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Sigalov AB. Multichain immune recognition receptor signaling: different players, same game? Trends Immunol 2005; 25:583-9. [PMID: 15489186 DOI: 10.1016/j.it.2004.08.009] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Alexander B Sigalov
- Department of Pathology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA.
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22
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Liu X, Manser T. Antinuclear antigen B cells that down-regulate surface B cell receptor during development to mature, follicular phenotype do not display features of anergy in vitro. THE JOURNAL OF IMMUNOLOGY 2005; 174:4505-15. [PMID: 15814671 DOI: 10.4049/jimmunol.174.8.4505] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
We previously demonstrated that B cells expressing a transgenic BCR with "dual reactivity" for the hapten arsonate and nuclear autoantigens efficiently complete development to follicular phenotype and stably reside in follicles in vivo. These B cells express very low levels of surface IgM and IgD, suggesting that they avoid central deletion and peripheral anergy by reducing their avidity for autoantigen via surface BCR (sBCR) down-regulation. Since a variety of states of B cell anergy have been previously described, a thorough examination of the functional capabilities of these B cells was required to test this hypothesis. In this study, we show that surface Ig cross-linking induces amounts of proximal BCR signaling in these B cells commensurate with their reduced sBCR levels. Functionally, however, they are comparable to nonautoreactive B cells in cell cycle progression, up-regulation of activation and costimulatory molecules, and Ab-forming cell differentiation when treated with a variety of stimuli in vitro. In addition, these B cells can efficiently process and present Ag and are capable of undergoing cognate interaction with naive TCR-transgenic T cells, resulting in robust IL-2 production. Together, these data reveal a lack of intrinsic anergy involving any known mechanism, supporting the idea that this type of antinuclear Ag B cell becomes indifferent to cognate autoantigen by down-regulating sBCR.
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MESH Headings
- Animals
- Antibody-Producing Cells/cytology
- Antibody-Producing Cells/immunology
- Antigen Presentation
- Autoantigens/metabolism
- B-Lymphocytes/cytology
- B-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/immunology
- Cell Cycle
- Cell Differentiation
- Cell Nucleus/immunology
- Clonal Anergy
- Down-Regulation
- Hybridomas/immunology
- In Vitro Techniques
- Lymphocyte Activation
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Mutation
- Phenotype
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, Antigen, B-Cell/genetics
- Receptors, Antigen, B-Cell/metabolism
- Receptors, Antigen, T-Cell/genetics
- Receptors, Antigen, T-Cell/metabolism
- Signal Transduction
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Affiliation(s)
- Xiaohe Liu
- Department of Microbiology and Immunology and Kimmel Cancer Center, Jefferson Medical College, Philadelphia, PA 19017-5541, USA
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23
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Vuillier F, Dumas G, Magnac C, Prevost MC, Lalanne AI, Oppezzo P, Melanitou E, Dighiero G, Payelle-Brogard B. Lower levels of surface B-cell-receptor expression in chronic lymphocytic leukemia are associated with glycosylation and folding defects of the μ and CD79a chains. Blood 2005; 105:2933-40. [PMID: 15591116 DOI: 10.1182/blood-2004-09-3643] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractLow levels of B-cell-receptor (BCR) expression are the hallmark of tumoral B lymphocytes in B-cell chronic lymphocytic leukemia (B-CLL). These cells also respond inadequately to stimulation through the BCR. This receptor consists of a surface immunoglobulin associated with a CD79a/CD79b heterodimer. We previously showed that the intracellular synthesis of BCR components, from transcription onward, is normal. Here, we investigated the glycosylation status and cellular localization of μ, CD79a, and CD79b chains in 10 CLL patients differing in surface immunoglobulin M (IgM) expression. We reported a severe impairment of the glycosylation and folding of μ and CD79a. These defects were associated with the retention of both chains in the endoplasmic reticulum and lower levels of surface IgM expression. In contrast, no clear impairment of glycosylation and folding was observed for CD79b. No sequence defects were identified for BCR components and for the chaperone proteins involved in BCR folding processes. These data show, for the first time, that lower levels of BCR surface expression observed in CLL are accounted for by an impaired glycosylation and folding of the μ and CD79a chains.
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MESH Headings
- Aged
- Antigens, CD/chemistry
- Antigens, CD/genetics
- Antigens, CD/metabolism
- B-Lymphocytes/metabolism
- B-Lymphocytes/ultrastructure
- CD79 Antigens
- Dimerization
- Endoplasmic Reticulum/metabolism
- Endoplasmic Reticulum/ultrastructure
- Female
- Gene Expression Regulation, Leukemic
- Glycosylation
- Golgi Apparatus/metabolism
- Golgi Apparatus/ultrastructure
- Humans
- Immunoglobulin M/chemistry
- Immunoglobulin M/genetics
- Immunoglobulin M/metabolism
- Leukemia, Lymphocytic, Chronic, B-Cell/metabolism
- Leukemia, Lymphocytic, Chronic, B-Cell/physiopathology
- Male
- Microscopy, Electron
- Middle Aged
- Molecular Chaperones/metabolism
- Protein Folding
- Receptor Aggregation
- Receptors, Antigen, B-Cell/chemistry
- Receptors, Antigen, B-Cell/genetics
- Receptors, Antigen, B-Cell/metabolism
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Affiliation(s)
- Françoise Vuillier
- Unité d'Immuno-Hématologie et d'Immunopathologie, Plate-forme de Microscopie Electronique, Institut Pasteur, 28 rue du Dr Roux, 75724 Paris Cedex 15, France.
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24
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Harnett MM, Katz E, Ford CA. Differential signalling during B-cell maturation. Immunol Lett 2005; 98:33-44. [PMID: 15790506 DOI: 10.1016/j.imlet.2004.11.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2004] [Revised: 11/04/2004] [Accepted: 11/07/2004] [Indexed: 11/30/2022]
Abstract
The molecular mechanism by which the antigen receptors (BCR) on B cells can elicit differential maturation state-specific responses is one of the central problems in B-cell differentiation yet to be resolved. Indeed, many of the early signalling events detected following BCR ligation, such as activation of protein tyrosine kinases (PTK), phospholipase C (PLC), phosphoinositide-3-kinase (PI 3K), protein kinase C (PKC) and the RasMAPK (mitogen activating protein kinase) signalling cascades are observed throughout B-cell maturation. However, it is becoming clear that the differential functional responses of these BCR-coupled signals observed during B-cell maturation are dependent on a number of parameters including signal strength and duration, subcellular localisation of the signal, maturation-restricted expression of downstream signalling effector elements/isoforms and modulation of signal by co-receptors. Thus, the combined signature of BCR signalling is likely to dictate the functional response and act as a developmental checkpoint for B-cell maturation.
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Affiliation(s)
- Margaret M Harnett
- Division of Immunology, Infection and Inflammation, University of Glasgow, Glasgow G116NT, UK.
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25
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Dighiero G. Perspectives in chronic lymphocytic leukemia biology and management. Hematol Oncol Clin North Am 2004; 18:927-43, x. [PMID: 15325707 DOI: 10.1016/j.hoc.2004.04.002] [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: 11/24/2022]
Abstract
Considerable progress has been achieved in the comprehension of the pathogenesis, prognosis, assessment, and treatment of chronic lymphocytic leukemia. However, this progress also has introduced new enigmas in the fields of biology, prognosis, and treatment. This article discusses some unanswered questions in these different topics.
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MESH Headings
- Genes, Immunoglobulin
- Humans
- Leukemia, Lymphocytic, Chronic, B-Cell/immunology
- Leukemia, Lymphocytic, Chronic, B-Cell/pathology
- Leukemia, Lymphocytic, Chronic, B-Cell/physiopathology
- Leukemia, Lymphocytic, Chronic, B-Cell/therapy
- Prognosis
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Affiliation(s)
- Guillaume Dighiero
- Unité d'Immuno-Hématologie et d'Immunopathologie, Institut Pasteur, 28 rue du Dr Roux F-75724 Paris cedex 15, France.
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26
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Stevenson FK, Caligaris-Cappio F. Chronic lymphocytic leukemia: revelations from the B-cell receptor. Blood 2004; 103:4389-95. [PMID: 14962897 DOI: 10.1182/blood-2003-12-4312] [Citation(s) in RCA: 305] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
The finding that chronic lymphocytic leukemia (CLL) consists of 2 clinical subsets, distinguished by the incidence of somatic mutations in the immunoglobulin (Ig) variable region (V) genes, has clearly linked prognosis to biology. Antigen encounter by the cell of origin is indicated in both subsets by selective but distinct expression of V genes, with evidence for continuing stimulation after transformation. The key to distinctive tumor behavior likely relates to the differential ability of the B-cell receptor (BCR) to respond. Both subsets may be undergoing low-level signaling in vivo, although analysis of blood cells limits knowledge of critical events in the tissue microenvironment. Analysis of signal competence in vitro reveals that unmutated CLL generally continues to respond, whereas mutated CLL is anergized. Differential responsiveness may reflect the increased ability of post-germinal center B cells to be triggered by antigen, leading to long-term anergy. This could minimize cell division in mutated CLL and account for prognostic differences. Unifying features of CLL include low responsiveness, expression of CD25, and production of immunosuppressive cytokines. These properties are reminiscent of regulatory T cells and suggest that the cell of origin of CLL might be a regulatory B cell. Continuing regulatory activity, mediated via autoantigen, could suppress Ig production and lead to disease-associated hypogammaglobulinemia. (Blood. 2004;103:4389-4395)
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Affiliation(s)
- Freda K Stevenson
- Molecular Immunology Group, Tenovus Laboratory, Cancer Sciences Division, Southampton University Hospitals Trust, Southampton SO16 6YD, United Kingdom.
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27
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Coffield VM, Jiang Q, Su L. A genetic approach to inactivating chemokine receptors using a modified viral protein. Nat Biotechnol 2003; 21:1321-7. [PMID: 14555957 PMCID: PMC4414054 DOI: 10.1038/nbt889] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2003] [Accepted: 08/22/2003] [Indexed: 11/09/2022]
Abstract
We have developed a genetic system, called degrakine, that specifically and stably inactivates chemokine receptors (CKR) by redirecting the ability of the HIV-1 protein, Vpu, to degrade CD4 in the endoplasmic reticulum (ER) via the host proteasome machinery. To harness Vpu's proteolytic targeting capability to degrade new receptors, we fused a chemokine with the C terminal region of Vpu. The fusion protein, or degrakine, accumulates in the ER, trapping and functionally inactivating its target CKR. We have demonstrated that degrakines based on SDF-1 (CXCL12), MDC (CCL22) and RANTES (CCL5) specifically inactivate their respective receptor functions. Using a retroviral vector expressing the SDF-1 degrakine, we have established that CXCR4 is required for the homing of hematopoietic stem/progenitor cells (HSPC) to the bone marrow immediately after transplantation. Thus the degrakine provides an effective genetic tool to dissect receptor functions in a number of biological systems in vitro and in vivo.
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Affiliation(s)
- V McNeil Coffield
- Curriculum in Genetics and Molecular Biology, and 22-048 Lineberger Cancer Center, School of Medicine, The University of North Carolina, Chapel Hill, NC 27599-7295, USA
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28
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Abstract
The lymphocyte's decision between tolerance and immunity/autoimmunity is regulated at many levels. Two important parameters in this decision are the maturation state of the antigen presenting cells (APCs) and the amount of self antigen that is detected by the immune system. Maturation of APCs occurs as a consequence of signals received by the innate immune system and may lead to the breakdown of tolerance. Particularly relevant to this process are the Toll-like receptors and mechanisms of cross presentation of self antigens. In addition, genetic alterations in a variety of cell surface receptors, signalling components and regulators of apoptosis/survival can break tolerance and lead to autoimmunity in vivo.
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Affiliation(s)
- Pamela S Ohashi
- University Health Network, Ontario Cancer Institute, Toronto, Canada.
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29
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Shaffer AL, Rosenwald A, Staudt LM. Lymphoid malignancies: the dark side of B-cell differentiation. Nat Rev Immunol 2002; 2:920-32. [PMID: 12461565 DOI: 10.1038/nri953] [Citation(s) in RCA: 305] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
When the regulation of B-cell differentiation and activation is disrupted, lymphomas and leukaemias can occur. The processes that normally create immunoglobulin diversity might be misdirected, resulting in oncogenic chromosomal translocations that block differentiation, prevent apoptosis and/or promote proliferation. Prolonged or unregulated antigenic stimulation might contribute further to the development and progression of some malignancies. Lymphoid malignancies often resemble normal stages of B-cell differentiation, as shown by molecular techniques such as gene-expression profiling. The similarities and differences between malignant and normal B cells indicate strategies for the treatment of these cancers.
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Affiliation(s)
- A L Shaffer
- Metabolism Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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30
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Baldari CT. Antigen receptor signaling under the Tuscan sun. Nat Immunol 2002; 3:1053-5. [PMID: 12407415 DOI: 10.1038/ni1102-1053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Cosima T Baldari
- Department of Evolutionary Biology, University of Siena, Via A. Moro 2, 53100 Siena, Italy.
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