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Baysac K, Sun G, Nakano H, Schmitz EG, Cruz AC, Fisher C, Bailey AC, Mace E, Milner JD, Ombrello MJ. PLCG2-associated immune dysregulation (PLAID) comprises broad and distinct clinical presentations related to functional classes of genetic variants. J Allergy Clin Immunol 2024; 153:230-242. [PMID: 37769878 PMCID: PMC11337301 DOI: 10.1016/j.jaci.2023.08.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 08/11/2023] [Accepted: 08/21/2023] [Indexed: 10/02/2023]
Abstract
BACKGROUND Pathogenic variants of phospholipase C gamma 2 (PLCG2) cause 2 related forms of autosomal-dominant immune dysregulation (ID), PLCγ2-associated antibody deficiency and immune dysregulation (PLAID) and autoinflammatory PLAID (APLAID). Since describing these conditions, many PLCG2 variants of uncertain significance have been identified by clinical sequencing of patients with diverse features of ID. OBJECTIVE We sought to functionally classify PLCG2 variants and explore known and novel genotype-function-phenotype relationships. METHODS Clinical data from patients with PLCG2 variants were obtained via standardized questionnaire. PLCG2 variants were generated by mutagenesis of enhanced green fluorescent protein (EGFP)-PLCG2 plasmid, which was overexpressed in Plcg2-deficient DT-40 B cells. B-cell receptor-induced calcium flux and extracellular signal-regulated kinase phosphorylation were assayed by flow cytometry. In some cases, stimulation-induced calcium flux was also measured in primary patient cells. RESULTS Three-fourths of PLCG2 variants produced functional alteration of B-cell activation, in vitro. Thirteen variants led to gain of function (GOF); however, most functional variants defined a new class of PLCG2 mutation, monoallelic loss of function (LOF). Susceptibility to infection and autoinflammation were common with both GOF and LOF variants, whereas a new phenotypic cluster consisting of humoral immune deficiency, autoinflammation, susceptibility to herpesvirus infection, and natural killer cell dysfunction was observed in association with multiple heterozygous LOF variants detected in both familial and sporadic cases. In some cases, PLCG2 variants produced greater effects in natural killer cells than in B cells. CONCLUSIONS This work expands the genotypic and phenotypic associations with functional variation in PLCG2, including a novel form of ID in carriers of heterozygous loss of PLCG2 function. It also demonstrates the need for more diverse assays for assessing the impact of PLCG2 variants on human disease.
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Affiliation(s)
- Kathleen Baysac
- Translational Genetics and Genomics Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Md
| | - Guangping Sun
- Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Md
| | - Hiroto Nakano
- Translational Genetics and Genomics Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Md
| | - Elizabeth G Schmitz
- Translational Genetics and Genomics Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Md
| | - Anthony C Cruz
- Translational Genetics and Genomics Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Md
| | - Charles Fisher
- Translational Genetics and Genomics Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Md
| | - Alexis C Bailey
- Translational Genetics and Genomics Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Md
| | - Emily Mace
- Division of Allergy, Immunology and Rheumatology, Department of Pediatrics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY
| | - Joshua D Milner
- Division of Allergy, Immunology and Rheumatology, Department of Pediatrics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY
| | - Michael J Ombrello
- Translational Genetics and Genomics Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Md.
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2
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Alinger JB, Mace EM, Porter JR, Mah-Som AY, Daugherty AL, Li S, Throm AA, Pingel JT, Saucier N, Yao A, Chinn IK, Lupski JR, Ehlayel M, Keller M, Bowman GR, Cooper MA, Orange JS, French AR. Human PLCG2 haploinsufficiency results in a novel natural killer cell immunodeficiency. J Allergy Clin Immunol 2024; 153:216-229. [PMID: 37714437 DOI: 10.1016/j.jaci.2023.09.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 08/30/2023] [Accepted: 09/04/2023] [Indexed: 09/17/2023]
Abstract
BACKGROUND Although most individuals effectively control herpesvirus infections, some suffer from severe and/or recurrent infections. A subset of these patients possess defects in natural killer (NK) cells, lymphocytes that recognize and lyse herpesvirus-infected cells; however, the genetic etiology is rarely diagnosed. PLCG2 encodes a signaling protein in NK-cell and B-cell signaling. Dominant-negative or gain-of-function variants in PLCG2 cause cold urticaria, antibody deficiency, and autoinflammation. However, loss-of-function variants and haploinsufficiency have not been reported to date. OBJECTIVES The investigators aimed to identify the genetic cause of NK-cell immunodeficiency in 2 families and herein describe the functional consequences of 2 novel loss-of-function variants in PLCG2. METHODS The investigators employed whole-exome sequencing in conjunction with mass cytometry, microscopy, functional assays, and a mouse model of PLCG2 haploinsufficiency to investigate 2 families with NK-cell immunodeficiency. RESULTS The investigators identified novel heterozygous variants in PLCG2 in 2 families with severe and/or recurrent herpesvirus infections. In vitro studies demonstrated that these variants were loss of function due to haploinsufficiency with impaired NK-cell calcium flux and cytotoxicity. In contrast to previous PLCG2 variants, B-cell function remained intact. Plcg2+/- mice also displayed impaired NK-cell function with preserved B-cell function, phenocopying human disease. CONCLUSIONS PLCG2 haploinsufficiency represents a distinct syndrome from previous variants characterized by NK-cell immunodeficiency with herpesvirus susceptibility, expanding the spectrum of PLCG2-related disease.
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Affiliation(s)
- Joshua B Alinger
- Division of Rheumatology, Department of Pediatrics, St Louis Children's Hospital, Washington University School of Medicine, St Louis, Mo
| | - Emily M Mace
- Departments of Pediatrics, Baylor College of Medicine, Center for Human Immunobiology, Texas Children's Hospital, Houston, Tex; Center for Human Immunobiology, Texas Children's Hospital, Houston, Tex; Department of Pediatrics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
| | - Justin R Porter
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St Louis, Mo
| | - Annelise Y Mah-Som
- Division of Rheumatology, Department of Pediatrics, St Louis Children's Hospital, Washington University School of Medicine, St Louis, Mo
| | - Allyssa L Daugherty
- Division of Rheumatology, Department of Pediatrics, St Louis Children's Hospital, Washington University School of Medicine, St Louis, Mo
| | - Stephanie Li
- Division of Rheumatology, Department of Pediatrics, St Louis Children's Hospital, Washington University School of Medicine, St Louis, Mo
| | - Allison A Throm
- Division of Rheumatology, Department of Pediatrics, St Louis Children's Hospital, Washington University School of Medicine, St Louis, Mo
| | - Jeanette T Pingel
- Division of Rheumatology, Department of Pediatrics, St Louis Children's Hospital, Washington University School of Medicine, St Louis, Mo
| | - Nermina Saucier
- Division of Rheumatology, Department of Pediatrics, St Louis Children's Hospital, Washington University School of Medicine, St Louis, Mo
| | - Albert Yao
- Division of Rheumatology, Department of Pediatrics, St Louis Children's Hospital, Washington University School of Medicine, St Louis, Mo
| | - Ivan K Chinn
- Departments of Pediatrics, Baylor College of Medicine, Center for Human Immunobiology, Texas Children's Hospital, Houston, Tex; Center for Human Immunobiology, Texas Children's Hospital, Houston, Tex
| | - James R Lupski
- Departments of Molecular and Human Genetics, Baylor College of Medicine, Texas Children's Hospital, Houston, Tex
| | | | | | - Greg R Bowman
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St Louis, Mo
| | - Megan A Cooper
- Division of Rheumatology, Department of Pediatrics, St Louis Children's Hospital, Washington University School of Medicine, St Louis, Mo
| | - Jordan S Orange
- Departments of Pediatrics, Baylor College of Medicine, Center for Human Immunobiology, Texas Children's Hospital, Houston, Tex; Center for Human Immunobiology, Texas Children's Hospital, Houston, Tex; Department of Pediatrics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
| | - Anthony R French
- Division of Rheumatology, Department of Pediatrics, St Louis Children's Hospital, Washington University School of Medicine, St Louis, Mo.
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3
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Wade-Vallance AK, Yang Z, Libang JB, Robinson MJ, Tarlinton DM, Allen CD. B cell receptor ligation induces IgE plasma cell elimination. J Exp Med 2023; 220:e20220964. [PMID: 36880536 PMCID: PMC9997509 DOI: 10.1084/jem.20220964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 11/17/2022] [Accepted: 01/31/2023] [Indexed: 03/08/2023] Open
Abstract
The proper regulation of IgE production safeguards against allergic disease, highlighting the importance of mechanisms that restrict IgE plasma cell (PC) survival. IgE PCs have unusually high surface B cell receptor (BCR) expression, yet the functional consequences of ligating this receptor are unknown. Here, we found that BCR ligation induced BCR signaling in IgE PCs followed by their elimination. In cell culture, exposure of IgE PCs to cognate antigen or anti-BCR antibodies induced apoptosis. IgE PC depletion correlated with the affinity, avidity, amount, and duration of antigen exposure and required the BCR signalosome components Syk, BLNK, and PLCγ2. In mice with a PC-specific impairment of BCR signaling, the abundance of IgE PCs was selectively increased. Conversely, BCR ligation by injection of cognate antigen or anti-IgE depleted IgE PCs. These findings establish a mechanism for the elimination of IgE PCs through BCR ligation. This has important implications for allergen tolerance and immunotherapy as well as anti-IgE monoclonal antibody treatments.
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Affiliation(s)
- Adam K. Wade-Vallance
- Biomedical Sciences Graduate Program, University of California, San Francisco, San Francisco, CA, USA
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, USA
- Sandler Asthma Basic Research Center, University of California, San Francisco, San Francisco, CA, USA
| | - Zhiyong Yang
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, USA
- Sandler Asthma Basic Research Center, University of California, San Francisco, San Francisco, CA, USA
| | - Jeremy B. Libang
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, USA
- Sandler Asthma Basic Research Center, University of California, San Francisco, San Francisco, CA, USA
| | - Marcus J. Robinson
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, USA
- Sandler Asthma Basic Research Center, University of California, San Francisco, San Francisco, CA, USA
- Department of Immunology and Pathology, Monash University, Melbourne, Australia
| | - David M. Tarlinton
- Department of Immunology and Pathology, Monash University, Melbourne, Australia
| | - Christopher D.C. Allen
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, USA
- Sandler Asthma Basic Research Center, University of California, San Francisco, San Francisco, CA, USA
- Department of Anatomy, University of California, San Francisco, San Francisco, CA, USA
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4
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Li K, Ran B, Wang Y, Liu L, Li W. PLCγ2 impacts microglia-related effectors revealing variants and pathways important in Alzheimer’s disease. Front Cell Dev Biol 2022; 10:999061. [PMID: 36147734 PMCID: PMC9485805 DOI: 10.3389/fcell.2022.999061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 08/15/2022] [Indexed: 11/30/2022] Open
Abstract
Alzheimer’s disease (AD) is an irreversible neurodegenerative disease mainly characterized by memory loss and cognitive decline. The etiology of AD is complex and remains incompletely understood. In recent years, genome-wide association studies (GWAS) have increasingly highlighted the central role of microglia in AD pathology. As a trans-membrane receptor specifically present on the microglia in the central nervous system, phosphatidylinositol-specific phospholipase C gamma 2 (PLCγ2) plays an important role in neuroinflammation. GWAS data and corresponding pathological research have explored the effects of PLCG2 variants on amyloid burden and tau pathologies that underline AD. The link between PLCγ2 and other AD-related effectors in human and mouse microglia has also been established, placing PLCγ2 downstream of the triggering receptor expressed on myeloid cells 2 (TREM2), toll-like receptor 4 (TLR4), Bruton’s tyrosine kinase (BTK), and colony-stimulating factor 1 receptor (CSF1R). Because the research on PLCγ2’s role in AD is still in its early stages, few articles have been published, therefore in this paper, we integrate the relevant research published to date, review the structural features, expression patterns, and related pathways of PLCγ2, and summarize the recent studies on important PLCG2 variants related to AD. Furthermore, the possibility and challenge of using PLCγ2 to develop therapeutic drugs for AD are also discussed.
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5
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Newman R, Tolar P. Chronic calcium signaling in IgE + B cells limits plasma cell differentiation and survival. Immunity 2021; 54:2756-2771.e10. [PMID: 34879220 DOI: 10.1016/j.immuni.2021.11.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 07/30/2021] [Accepted: 11/12/2021] [Indexed: 01/28/2023]
Abstract
In contrast to other antibody isotypes, B cells switched to IgE respond transiently and do not give rise to long-lived plasma cells (PCs) or memory B cells. To better understand IgE-BCR-mediated control of IgE responses, we developed whole-genome CRISPR screening that enabled comparison of IgE+ and IgG1+ B cell requirements for proliferation, survival, and differentiation into PCs. IgE+ PCs exhibited dependency on the PI3K-mTOR axis that increased protein amounts of the transcription factor IRF4. In contrast, loss of components of the calcium-calcineurin-NFAT pathway promoted IgE+ PC differentiation. Mice bearing a B cell-specific deletion of calcineurin B1 exhibited increased production of IgE+ PCs. Mechanistically, sustained elevation of intracellular calcium in IgE+ PCs downstream of the IgE-BCR promoted BCL2L11-dependent apoptosis. Thus, chronic calcium signaling downstream of the IgE-BCR controls the self-limiting character of IgE responses and may be relevant to the accumulation of IgE-producing cells in allergic disease.
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Affiliation(s)
- Rebecca Newman
- Immune Receptor Activation Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Pavel Tolar
- Immune Receptor Activation Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK; Division of Infection and Immunity, Institute of Immunity and Transplantation, University College London, London NW3 2PF, UK.
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6
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Maguire E, Menzies GE, Phillips T, Sasner M, Williams HM, Czubala MA, Evans N, Cope EL, Sims R, Howell GR, Lloyd-Evans E, Williams J, Allen ND, Taylor PR. PIP2 depletion and altered endocytosis caused by expression of Alzheimer's disease-protective variant PLCγ2 R522. EMBO J 2021; 40:e105603. [PMID: 34254352 PMCID: PMC8408593 DOI: 10.15252/embj.2020105603] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 05/06/2021] [Accepted: 06/04/2021] [Indexed: 02/06/2023] Open
Abstract
Variants identified in genome-wide association studies have implicated immune pathways in the development of Alzheimer's disease (AD). Here, we investigated the mechanistic basis for protection from AD associated with PLCγ2 R522, a rare coding variant of the PLCG2 gene. We studied the variant's role in macrophages and microglia of newly generated PLCG2-R522-expressing human induced pluripotent cell lines (hiPSC) and knockin mice, which exhibit normal endogenous PLCG2 expression. In all models, cells expressing the R522 mutation show a consistent non-redundant hyperfunctionality in the context of normal expression of other PLC isoforms. This manifests as enhanced release of cellular calcium ion stores in response to physiologically relevant stimuli like Fc-receptor ligation or exposure to Aβ oligomers. Expression of the PLCγ2-R522 variant resulted in increased stimulus-dependent PIP2 depletion and reduced basal PIP2 levels in vivo. Furthermore, it was associated with impaired phagocytosis and enhanced endocytosis. PLCγ2 acts downstream of other AD-related factors, such as TREM2 and CSF1R, and alterations in its activity directly impact cell function. The inherent druggability of enzymes such as PLCγ2 raises the prospect of PLCγ2 manipulation as a future therapeutic approach in AD.
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Affiliation(s)
- Emily Maguire
- UK Dementia Research Institute at Cardiff, Cardiff, UK
| | - Georgina E Menzies
- UK Dementia Research Institute at Cardiff, Cardiff, UK.,School of Biosciences, Cardiff University, Cardiff, UK
| | | | | | | | | | - Neil Evans
- UK Dementia Research Institute at Cardiff, Cardiff, UK
| | - Emma L Cope
- School of Biosciences, Cardiff University, Cardiff, UK
| | - Rebecca Sims
- MRC Centre for Neuropsychiatric Genetics & Genomics, Cardiff, UK
| | | | | | - Julie Williams
- UK Dementia Research Institute at Cardiff, Cardiff, UK.,MRC Centre for Neuropsychiatric Genetics & Genomics, Cardiff, UK
| | | | - Philip R Taylor
- UK Dementia Research Institute at Cardiff, Cardiff, UK.,Systems Immunity University Research Institute, Cardiff, UK
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7
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Jackson JT, Mulazzani E, Nutt SL, Masters SL. The role of PLCγ2 in immunological disorders, cancer, and neurodegeneration. J Biol Chem 2021; 297:100905. [PMID: 34157287 PMCID: PMC8318911 DOI: 10.1016/j.jbc.2021.100905] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 06/15/2021] [Accepted: 06/18/2021] [Indexed: 02/06/2023] Open
Abstract
Phosphatidylinositol-specific phospholipase Cγ2 (PLCγ2) is a critical signaling molecule activated downstream from a variety of cell surface receptors that contain an intracellular immunoreceptor tyrosine-based activation motif. These receptors recruit kinases such as Syk, BTK, and BLNK to phosphorylate and activate PLCγ2, which then generates 1D-myo-inositol 1,4,5-trisphosphate and diacylglycerol. These well-known second messengers are required for diverse membrane functionality including cellular proliferation, endocytosis, and calcium flux. As a result, PLCγ2 dysfunction is associated with a variety of diseases including cancer, neurodegeneration, and immune disorders. The diverse pathologies associated with PLCγ2 are exemplified by distinct genetic variants. Inherited mutations at this locus cause PLCγ2-associated antibody deficiency and immune dysregulation, in some cases with autoinflammation. Acquired mutations at this locus, which often arise as a result of BTK inhibition to treat chronic lymphocytic leukemia, result in constitutive downstream signaling and lymphocyte proliferation. Finally, a third group of PLCγ2 variants actually has a protective effect in a variety of neurodegenerative disorders, presumably by increased uptake and degradation of deleterious neurological aggregates. Therefore, manipulating PLCγ2 activity either up or down could have therapeutic benefit; however, we require a better understanding of the signaling pathways propagated by these variants before such clinical utility can be realized. Here, we review the signaling roles of PLCγ2 in hematopoietic cells to help understand the effect of mutations driving immune disorders and cancer and extrapolate from this to roles which may relate to protection against neurodegeneration.
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Affiliation(s)
- Jacob T Jackson
- Immunology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
| | - Elisabeth Mulazzani
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Stephen L Nutt
- Immunology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Seth L Masters
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia; Immunology Laboratory, Guangzhou Institute of Paediatrics, Guangzhou Women and Children's Medical Centre, Guangzhou, Guangdong, China.
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8
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Pyfrom SC, Quinn CC, Dorando HK, Luo H, Payton JE. BCALM (AC099524.1) Is a Human B Lymphocyte-Specific Long Noncoding RNA That Modulates B Cell Receptor-Mediated Calcium Signaling. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2020; 205:595-607. [PMID: 32571842 PMCID: PMC7372127 DOI: 10.4049/jimmunol.2000088] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 05/27/2020] [Indexed: 12/12/2022]
Abstract
Of the thousands of long noncoding RNAs (lncRNA) identified in lymphocytes, very few have defined functions. In this study, we report the discovery and functional elucidation of a human B cell-specific lncRNA with high levels of expression in three types of B cell cancer and normal B cells. The AC099524.1 gene is upstream of the gene encoding the B cell-specific phospholipase C γ 2 (PLCG2), a B cell-specific enzyme that stimulates intracellular Ca2+ signaling in response to BCR activation. AC099524.1 (B cell-associated lncRNA modulator of BCR-mediated Ca+ signaling [BCALM]) transcripts are localized in the cytoplasm and, as expected, CRISPR/Cas9 knockout of AC099524.1 did not affect PLCG2 mRNA or protein expression. lncRNA interactome, RNA immunoprecipitation, and coimmunoprecipitation studies identified BCALM-interacting proteins in B cells, including phospholipase D 1 (PLD1), and kinase adaptor proteins AKAP9 (AKAP450) and AKAP13 (AKAP-Lbc). These two AKAP proteins form signaling complexes containing protein kinases A and C, which phosphorylate and activate PLD1 to produce phosphatidic acid (PA). BCR stimulation of BCALM-deficient B cells resulted in decreased PLD1 phosphorylation and increased intracellular Ca+ flux relative to wild-type cells. These results suggest that BCALM promotes negative feedback that downmodulates BCR-mediated Ca+ signaling by promoting phosphorylation of PLD1 by AKAP-associated kinases, enhancing production of PA. PA activates SHP-1, which negatively regulates BCR signaling. We propose the name BCALM for B-Cell Associated LncRNA Modulator of BCR-mediated Ca+ signaling. Our findings suggest a new, to our knowledge, paradigm for lncRNA-mediated modulation of lymphocyte activation and signaling, with implications for B cell immune response and BCR-dependent cancers.
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Affiliation(s)
- Sarah C Pyfrom
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - Chaz C Quinn
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - Hannah K Dorando
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - Hong Luo
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - Jacqueline E Payton
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
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9
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Abstract
Primary atopic disorders describes a series of monogenic diseases that have allergy- or atopic effector–related symptoms as a substantial feature. The underlying pathogenic genetic lesions help illustrate fundamental pathways in atopy, opening up diagnostic and therapeutic options for further study in those patients, but ultimately for common allergic diseases as well. Key pathways affected in these disorders include T cell receptor and B cell receptor signaling, cytokine signaling, skin barrier function, and mast cell function, as well as pathways that have not yet been elucidated. While comorbidities such as classically syndromic presentation or immune deficiency are often present, in some cases allergy alone is the presenting symptom, suggesting that commonly encountered allergic diseases exist on a spectrum of monogenic and complex genetic etiologies that are impacted by environmental risk factors.
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Affiliation(s)
- Joshua D. Milner
- Department of Pediatrics, Columbia University Irving Medical Center, New York, NY 10032, USA
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10
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Ahmed R, Omidian Z, Giwa A, Cornwell B, Majety N, Bell DR, Lee S, Zhang H, Michels A, Desiderio S, Sadegh-Nasseri S, Rabb H, Gritsch S, Suva ML, Cahan P, Zhou R, Jie C, Donner T, Hamad ARA. A Public BCR Present in a Unique Dual-Receptor-Expressing Lymphocyte from Type 1 Diabetes Patients Encodes a Potent T Cell Autoantigen. Cell 2020; 177:1583-1599.e16. [PMID: 31150624 DOI: 10.1016/j.cell.2019.05.007] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 12/10/2018] [Accepted: 05/02/2019] [Indexed: 12/17/2022]
Abstract
T and B cells are the two known lineages of adaptive immune cells. Here, we describe a previously unknown lymphocyte that is a dual expresser (DE) of TCR and BCR and key lineage markers of both B and T cells. In type 1 diabetes (T1D), DEs are predominated by one clonotype that encodes a potent CD4 T cell autoantigen in its antigen binding site. Molecular dynamics simulations revealed that this peptide has an optimal binding register for diabetogenic HLA-DQ8. In concordance, a synthetic version of the peptide forms stable DQ8 complexes and potently stimulates autoreactive CD4 T cells from T1D patients, but not healthy controls. Moreover, mAbs bearing this clonotype are autoreactive against CD4 T cells and inhibit insulin tetramer binding to CD4 T cells. Thus, compartmentalization of adaptive immune cells into T and B cells is not absolute, and violators of this paradigm are likely key drivers of autoimmune diseases.
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Affiliation(s)
- Rizwan Ahmed
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Zahra Omidian
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Adebola Giwa
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Benjamin Cornwell
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Neha Majety
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - David R Bell
- Computational Biology Center, IBM Thomas J. Watson Research Center, Yorktown Heights, NY 10598, USA
| | - Sangyun Lee
- Computational Biology Center, IBM Thomas J. Watson Research Center, Yorktown Heights, NY 10598, USA
| | - Hao Zhang
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Aaron Michels
- Barbara Davis Center for Diabetes, University of Colorado, Aurora, CO 80045, USA
| | - Stephen Desiderio
- Department of Molecular Biology and Genetics and Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | | | - Hamid Rabb
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Simon Gritsch
- Department of Pathology and Center for Cancer Research, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02114, USA
| | - Mario L Suva
- Department of Pathology and Center for Cancer Research, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02114, USA; Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Patrick Cahan
- Department of Molecular Biology and Genetics and Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Ruhong Zhou
- Computational Biology Center, IBM Thomas J. Watson Research Center, Yorktown Heights, NY 10598, USA; Department of Chemistry, Columbia University, New York, NY 10027, USA.
| | - Chunfa Jie
- Department of Biochemistry and Nutrition, Des Moines University, Des Moines, IA 50312, USA
| | - Thomas Donner
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Abdel Rahim A Hamad
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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11
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Hajicek N, Keith NC, Siraliev-Perez E, Temple BRS, Huang W, Zhang Q, Harden TK, Sondek J. Structural basis for the activation of PLC-γ isozymes by phosphorylation and cancer-associated mutations. eLife 2019; 8:e51700. [PMID: 31889510 PMCID: PMC7004563 DOI: 10.7554/elife.51700] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 12/30/2019] [Indexed: 12/14/2022] Open
Abstract
Direct activation of the human phospholipase C-γ isozymes (PLC-γ1, -γ2) by tyrosine phosphorylation is fundamental to the control of diverse biological processes, including chemotaxis, platelet aggregation, and adaptive immunity. In turn, aberrant activation of PLC-γ1 and PLC-γ2 is implicated in inflammation, autoimmunity, and cancer. Although structures of isolated domains from PLC-γ isozymes are available, these structures are insufficient to define how release of basal autoinhibition is coupled to phosphorylation-dependent enzyme activation. Here, we describe the first high-resolution structure of a full-length PLC-γ isozyme and use it to underpin a detailed model of their membrane-dependent regulation. Notably, an interlinked set of regulatory domains integrates basal autoinhibition, tyrosine kinase engagement, and additional scaffolding functions with the phosphorylation-dependent, allosteric control of phospholipase activation. The model also explains why mutant forms of the PLC-γ isozymes found in several cancers have a wide spectrum of activities, and highlights how these activities are tuned during disease.
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Affiliation(s)
- Nicole Hajicek
- Department of PharmacologyThe University of North Carolina at Chapel HillChapel HillUnited States
| | - Nicholas C Keith
- Department of PharmacologyThe University of North Carolina at Chapel HillChapel HillUnited States
| | - Edhriz Siraliev-Perez
- Department of Biochemistry and BiophysicsThe University of North Carolina at Chapel HillChapel HillUnited States
| | - Brenda RS Temple
- Department of Biochemistry and BiophysicsThe University of North Carolina at Chapel HillChapel HillUnited States
- R L Juliano Structural Bioinformatics Core FacilityThe University of North Carolina at Chapel HillChapel HillUnited States
| | - Weigang Huang
- Division of Chemical Biology and Medicinal ChemistryThe University of North Carolina at Chapel HillChapel HillUnited States
| | - Qisheng Zhang
- Department of PharmacologyThe University of North Carolina at Chapel HillChapel HillUnited States
- Division of Chemical Biology and Medicinal ChemistryThe University of North Carolina at Chapel HillChapel HillUnited States
- Lineberger Comprehensive Cancer CenterThe University of North Carolina at Chapel HillChapel HillUnited States
| | - T Kendall Harden
- Department of PharmacologyThe University of North Carolina at Chapel HillChapel HillUnited States
| | - John Sondek
- Department of PharmacologyThe University of North Carolina at Chapel HillChapel HillUnited States
- Department of Biochemistry and BiophysicsThe University of North Carolina at Chapel HillChapel HillUnited States
- Lineberger Comprehensive Cancer CenterThe University of North Carolina at Chapel HillChapel HillUnited States
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12
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The regulators of BCR signaling during B cell activation. BLOOD SCIENCE 2019; 1:119-129. [PMID: 35402811 PMCID: PMC8975005 DOI: 10.1097/bs9.0000000000000026] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Accepted: 07/25/2019] [Indexed: 11/26/2022] Open
Abstract
B lymphocytes produce antibodies under the stimulation of specific antigens, thereby exerting an immune effect. B cells identify antigens by their surface B cell receptor (BCR), which upon stimulation, directs the cell to activate and differentiate into antibody generating plasma cells. Activation of B cells via their BCRs involves signaling pathways that are tightly controlled by various regulators. In this review, we will discuss three major BCR mediated signaling pathways (the PLC-γ2 pathway, PI3K pathway and MAPK pathway) and related regulators, which were roughly divided into positive, negative and mutual-balanced regulators, and the specific regulators of the specific signaling pathway based on regulatory effects.
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13
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Kwak K, Quizon N, Sohn H, Saniee A, Manzella-Lapeira J, Holla P, Brzostowski J, Lu J, Xie H, Xu C, Spillane KM, Tolar P, Pierce SK. Intrinsic properties of human germinal center B cells set antigen affinity thresholds. Sci Immunol 2019; 3:3/29/eaau6598. [PMID: 30504208 DOI: 10.1126/sciimmunol.aau6598] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 10/26/2018] [Indexed: 12/17/2022]
Abstract
Protective antibody responses to vaccination or infection depend on affinity maturation, a process by which high-affinity germinal center (GC) B cells are selected on the basis of their ability to bind, gather, and present antigen to T follicular helper (Tfh) cells. Here, we show that human GC B cells have intrinsically higher-affinity thresholds for both B cell antigen receptor (BCR) signaling and antigen gathering as compared with naïve B cells and that these functions are mediated by distinct cellular structures and pathways that ultimately lead to antigen affinity- and Tfh cell-dependent differentiation to plasma cells. GC B cells bound antigen through highly dynamic, actin- and ezrin-rich pod-like structures that concentrated BCRs. The behavior of these structures was dictated by the intrinsic antigen affinity thresholds of GC B cells. Low-affinity antigens triggered continuous engagement and disengagement of membrane-associated antigens, whereas high-affinity antigens induced stable synapse formation. The pod-like structures also mediated affinity-dependent antigen internalization by unconventional pathways distinct from those of naïve B cells. Thus, intrinsic properties of human GC B cells set thresholds for affinity selection.
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Affiliation(s)
- Kihyuck Kwak
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Nicolas Quizon
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Haewon Sohn
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Avva Saniee
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Javier Manzella-Lapeira
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Prasida Holla
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Joseph Brzostowski
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Jinghua Lu
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - HengYi Xie
- MOE Key Laboratory of Protein Sciences, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, School of Life Sciences, Institute for Immunology, Tsinghua University, Beijing, China
| | - Chenguang Xu
- MOE Key Laboratory of Protein Sciences, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, School of Life Sciences, Institute for Immunology, Tsinghua University, Beijing, China
| | - Katelyn M Spillane
- Department of Physics, King's College London, London WC2R 2LS, UK.,Immune Receptor Activation Laboratory, Francis Crick Institute, London NW1 1AT, UK.,Division of Immunology and Inflammation, Imperial College London, London SW7 2AZ, UK
| | - Pavel Tolar
- Immune Receptor Activation Laboratory, Francis Crick Institute, London NW1 1AT, UK.,Division of Immunology and Inflammation, Imperial College London, London SW7 2AZ, UK
| | - Susan K Pierce
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA.
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14
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Xiao B, Li J, Zhou M, Li X, Huang X, Hang J, Sun Z, Li L. [Structure and function of B-cell linker and its role in the development of B cell-related diseases]. NAN FANG YI KE DA XUE XUE BAO = JOURNAL OF SOUTHERN MEDICAL UNIVERSITY 2019; 39:253-256. [PMID: 30890517 DOI: 10.12122/j.issn.1673-4254.2019.02.20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
B cell linker (BLNK) is a key linker protein of B cell receptor (BCR) signaling pathway. BLNK participates in the regulation of PLC-γactivity and the activation of Ras pathway through its typical structure and interaction network with other proteins, and is thus widely involved in the regulation of B cell proliferation, differentiation, apoptosis and signal transduction. Furthermore, it is closely related to anaphylactic diseases, multiple sclerosis, chromosomal aneuploidy, aneuglobulinemia, B lymphocytic leukemia and lymphoma. Herein we review the structure and biological function of BLNK and its role in B cell-related diseases. BLNK can cooperate with a series of effective proteins to activate BCR signaling pathway, thereby regulating the development, maturation and function of B cells. The functional mutation of BLNK can destroy the homeostasis of B cells and affect the development and maturation of B cells, which leads to the occurrence of B cell related diseases. A comprehensive understanding of the biological functions of BLNK not only provides insights into the pathogenesis of B cell-related diseases, but also inspires new ideas and helps to find breakthroughs for the treatment of these diseases with BLNK as the therapeutic target.
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Affiliation(s)
- Bin Xiao
- Department of Laboratory Medicine, General Hospital of Southern Theatre Command of PLA, Guangzhou 510010, China
| | - Jiaying Li
- Department of Clinical Laboratory, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Mengsi Zhou
- Department of Clinical Laboratory, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Xiaoqing Li
- Department of Laboratory Medicine, General Hospital of Southern Theatre Command of PLA, Guangzhou 510010, China
| | - Xiaoyan Huang
- Department of Laboratory Medicine, General Hospital of Southern Theatre Command of PLA, Guangzhou 510010, China
| | - Jianfeng Hang
- Department of Laboratory Medicine, General Hospital of Southern Theatre Command of PLA, Guangzhou 510010, China
| | - Zhaohui Sun
- Department of Laboratory Medicine, General Hospital of Southern Theatre Command of PLA, Guangzhou 510010, China
| | - Linhai Li
- Department of Laboratory Medicine, General Hospital of Southern Theatre Command of PLA, Guangzhou 510010, China
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15
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Bajaj T, Ramirez A, Wagner-Thelen H. Genetik der Alzheimer-Krankheit. MED GENET-BERLIN 2018. [DOI: 10.1007/s11825-018-0193-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Zusammenfassung
Die Alzheimer-Erkrankung („Alzheimer’s disease“, AD) ist die häufigste Ursache der neurodegenerativen Demenzen. Im Gegensatz zu monogenen und meist frühmanifesten Formen der AD, welche auf hochpenetrante Mutationen in den Genen APP, PSEN1 und PSEN2 zurückzuführen sind, wird die Suszeptibilität für die sporadische, oft spätmanifeste Form der AD durch eine komplexe Wechselwirkung zwischen genetischen und epigenetischen Faktoren wie auch umwelt- und lebensstilbedingten Faktoren bestimmt. Obgleich APOE ε4 der stärkste genetische Risikofaktor für die AD ist, macht der Effekt des APOE ε4 lediglich 27,3 % der geschätzten Heritabilität von 58–79 % aus. Durch den kontinuierlichen technischen Fortschritt von GWAS (genomweite Assoziationsstudien) und automatisierten Sequenziermethoden der nächsten Generation gelingt es Wissenschaftlern in groß angelegten Kollaborationen sukzessive die fehlende Heritabilität aufzudecken. Wichtige Erkenntnisse aus GWAS und Signalweganalysen suggerieren, dass Mikroglia, die residenten Immunzellen des ZNS, eine entscheidende Rolle bei der Pathogenese der AD spielen. Eine beachtliche Anzahl der in genetischen Studien identifizierten Risikogene weisen immunsystembezogene Funktionen auf und werden in höchstem Maße von Mikroglia exprimiert. Durch die Beschreibung von Risikovarianten in CR1, CLU, SPI1, CD33, MS4A, ABCA7, EPHA1, HLA-DRB5/1, INPP5D, TYROBP, TREM2, PLCG2 und ABI3 nimmt die Mikroglia vermittelte Immunantwort bei der Pathogenese der AD eine zentrale Rolle ein. Von besonderer Bedeutung könnte sein, dass die PLCγ2-Variante p.P522R einen protektiven Effekt auf die LOAD („late-onset“ AD; spätmanifeste Form der AD) ausübt und als Enzym ein klassisches Ziel für eine therapeutische Modulation von komplexen Formen der AD darstellt.
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Affiliation(s)
- Thomas Bajaj
- Aff1 0000 0000 8852 305X grid.411097.a Sektion für Neurogenetik und Molekulare Neuropsychiatrie an der Klinik für Psychiatrie und Psychotherapie Uniklinik Köln Kerpener Straße 62 50937 Köln Deutschland
| | - Alfredo Ramirez
- Aff1 0000 0000 8852 305X grid.411097.a Sektion für Neurogenetik und Molekulare Neuropsychiatrie an der Klinik für Psychiatrie und Psychotherapie Uniklinik Köln Kerpener Straße 62 50937 Köln Deutschland
- Aff2 0000 0000 8786 803X grid.15090.3d Klinik für Neurodegenerative Erkrankungen und Gerontopsychiatrie Universitätsklinikum Bonn Sigmund-Freud-Straße 25 53127 Bonn Deutschland
| | - Holger Wagner-Thelen
- Aff1 0000 0000 8852 305X grid.411097.a Sektion für Neurogenetik und Molekulare Neuropsychiatrie an der Klinik für Psychiatrie und Psychotherapie Uniklinik Köln Kerpener Straße 62 50937 Köln Deutschland
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16
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Xu C, Xie H, Guo X, Gong H, Liu L, Qi H, Xu C, Liu W. A PIP 2-derived amplification loop fuels the sustained initiation of B cell activation. Sci Immunol 2018; 2:2/17/eaan0787. [PMID: 29150438 DOI: 10.1126/sciimmunol.aan0787] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 10/04/2017] [Indexed: 12/28/2022]
Abstract
Lymphocytes have evolved sophisticated signaling amplification mechanisms to efficiently activate downstream signaling after detection of rare ligands in their microenvironment. B cell receptor microscopic clusters (BCR microclusters) are assembled on the plasma membrane and recruit signaling molecules for the initiation of lymphocyte signaling after antigen binding. We identified a signaling amplification loop derived from phosphatidylinositol 4,5-biphosphate (PIP2) for the sustained B cell activation. Upon antigen recognition, PIP2 was depleted by phospholipase C-γ2 (PLC-γ2) within the BCR microclusters and was regenerated by phosphatidic acid-dependent type I phosphatidylinositol 4-phosphate 5-kinase outside the BCR microclusters. The hydrolysis of PIP2 inside the BCR microclusters induced a positive feedback mechanism for its synthesis outside the BCR microclusters. The falling gradient of PIP2 across the boundary of BCR microclusters was important for the efficient formation of BCR microclusters. Our results identified a PIP2-derived amplification loop that fuels the sustained initiation of B cell activation.
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Affiliation(s)
- Chenguang Xu
- Ministry of Education (MOE) Key Laboratory of Protein Sciences, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, School of Life Sciences, Institute for Immunology, Tsinghua University, Beijing 100084, China
| | - Hengyi Xie
- Ministry of Education (MOE) Key Laboratory of Protein Sciences, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, School of Life Sciences, Institute for Immunology, Tsinghua University, Beijing 100084, China
| | - Xingdong Guo
- National Center for Protein Science Shanghai, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Haipeng Gong
- MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Lei Liu
- Tsinghua-Peking Center for Life Sciences, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (MOE), Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Hai Qi
- Tsinghua-Peking Center for Life Sciences, Laboratory of Dynamic Immunobiology, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Chenqi Xu
- National Center for Protein Science Shanghai, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.,School of Life Science, ShanghaiTech University, Shanghai 201210, China
| | - Wanli Liu
- Ministry of Education (MOE) Key Laboratory of Protein Sciences, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, School of Life Sciences, Institute for Immunology, Tsinghua University, Beijing 100084, China.
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17
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Akkaya M, Akkaya B, Kim AS, Miozzo P, Sohn H, Pena M, Roesler AS, Theall BP, Henke T, Kabat J, Lu J, Dorward DW, Dahlstrom E, Skinner J, Miller LH, Pierce SK. Toll-like receptor 9 antagonizes antibody affinity maturation. Nat Immunol 2018; 19:255-266. [PMID: 29476183 PMCID: PMC5839995 DOI: 10.1038/s41590-018-0052-z] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 01/10/2018] [Indexed: 12/21/2022]
Abstract
Key events in T cell-dependent antibody responses, including affinity maturation, are dependent on the B cell’s presentation of antigen to helper T cells at critical check points in germinal center formation in secondary lymphoid organs. Here we show that Toll-like receptor 9 (TLR9) signaling blocked the ability of antigen-specific B cells to capture, process and present antigen and to activate antigen-specific helper T cells in vitro. In a mouse model in vivo and in a human clinical trial the TLR9 agonist, CpG, enhanced the magnitude of the antibody response to a protein vaccine but failed to promote affinity maturation. Thus, TLR9 signaling may enhance antibody titers at the expense of the ability of B cells to engage in germinal center events that are highly dependent on B cells’ antigen capture and presentation.
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Affiliation(s)
- Munir Akkaya
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Billur Akkaya
- Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Ann S Kim
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Pietro Miozzo
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Haewon Sohn
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Mirna Pena
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Alexander S Roesler
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Brandon P Theall
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Travis Henke
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Juraj Kabat
- Research Technologies Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Jinghua Lu
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - David W Dorward
- Research Technologies Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Eric Dahlstrom
- Research Technologies Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Jeff Skinner
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Louis H Miller
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Susan K Pierce
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA.
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18
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Cool-temperature-mediated activation of phospholipase C-γ2 in the human hereditary disease PLAID. Cell Signal 2016; 28:1237-1251. [PMID: 27196803 DOI: 10.1016/j.cellsig.2016.05.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Revised: 05/10/2016] [Accepted: 05/12/2016] [Indexed: 12/24/2022]
Abstract
Deletions in the gene encoding signal-transducing inositol phospholipid-specific phospholipase C-γ2 (PLCγ2) are associated with the novel human hereditary disease PLAID (PLCγ2-associated antibody deficiency and immune dysregulation). PLAID is characterized by a rather puzzling concurrence of augmented and diminished functions of the immune system, such as cold urticaria triggered by only minimal decreases in temperature, autoimmunity, and immunodeficiency. Understanding of the functional effects of the genomic alterations at the level of the affected enzyme, PLCγ2, is currently lacking. PLCγ2 is critically involved in coupling various cell surface receptors to regulation of important functions of immune cells such as mast cells, B cells, monocytes/macrophages, and neutrophils. PLCγ2 is unique by carrying three Src (SH) and one split pleckstrin homology domain (spPH) between the two catalytic subdomains (spPHn-SH2n-SH2c-SH3-spPHc). Prevailing evidence suggests that activation of PLCγ2 is primarily due to loss of SH-region-mediated autoinhibition and/or enhanced plasma membrane translocation. Here, we show that the two PLAID PLCγ2 mutants lacking portions of the SH region are strongly (>100-fold), rapidly, and reversibly activated by cooling by only a few degrees. We found that the mechanism(s) underlying PLCγ2 PLAID mutant activation by cool temperatures is distinct from a mere loss of SH-region-mediated autoinhibition and dependent on both the integrity and the pliability of the spPH domain. The results suggest a new mechanism of PLCγ activation with unique thermodynamic features and assign a novel regulatory role to its spPH domain. Involvement of this mechanism in other human disease states associated with cooling such as exertional asthma and certain acute coronary events appears an intriguing possibility.
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19
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Abstract
PLCG2 associated antibody deficiency and immune dysregulation (PLAID) is a complex dominantly inherited disease characterized almost universally by cold urticaria, and variably by recurrent bacterial infection, autoimmunty and skin granuloma formation. Several striking phenotypes can emerge from this disease, and the pathophysiology leads to a complex mix of loss and gain of function in cellular signaling. This review discusses the key phenotypic characteristics and pathophysiologic observations seen in PLAID, and contrasts PLAID to several related disorders in order to best contextualize this fascinating disease.
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Affiliation(s)
- Joshua D Milner
- Genetics and Pathogenesis of Allergy Section, Laboratory of Allergic Diseases, NIAID, NIH, 10 Center Drive, NIH Building 10-CRC 5-3950, Bethesda, MD, 20892, USA.
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20
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Boisson B, Quartier P, Casanova JL. Immunological loss-of-function due to genetic gain-of-function in humans: autosomal dominance of the third kind. Curr Opin Immunol 2015; 32:90-105. [PMID: 25645939 PMCID: PMC4364384 DOI: 10.1016/j.coi.2015.01.005] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 01/06/2015] [Accepted: 01/12/2015] [Indexed: 12/29/2022]
Abstract
All the human primary immunodeficiencies (PIDs) recognized as such in the 1950s were Mendelian traits and, whether autosomal or X-linked, displayed recessive inheritance. The first autosomal dominant (AD) PID, hereditary angioedema, was recognized in 1963. However, since the first identification of autosomal recessive (AR), X-linked recessive (XR) and AD PID-causing genes in 1985 (ADA; severe combined immunodeficiency), 1986 (CYBB, chronic granulomatous disease) and 1989 (SERPING1; hereditary angioedema), respectively, the number of genetically defined AD PIDs has increased more rapidly than that of any other type of PID. AD PIDs now account for 61 of the 260 known conditions (23%). All known AR PIDs are caused by alleles with some loss-of-function (LOF). A single XR PID is caused by gain-of-function (GOF) mutations (WASP-related neutropenia, 2001). In contrast, only 44 of 61 AD defects are caused by LOF alleles, which exert dominance by haploinsufficiency or negative dominance. Since 2003, up to 17 AD disorders of the third kind, due to GOF alleles, have been described. Remarkably, six of the 17 genes concerned also harbor monoallelic (STAT3), biallelic (C3, CFB, CARD11, PIK3R1) or both monoallelic and biallelic (STAT1) LOF alleles in patients with other clinical phenotypes. Most heterozygous GOF alleles result in auto-inflammation, auto-immunity, or both, with a wide range of immunological and clinical forms. Some also underlie infections and, fewer, allergies, by impairing or enhancing immunity to non-self. Malignancies are also rare. The enormous diversity of immunological and clinical phenotypes is thought provoking and mirrors the diversity and pleiotropy of the underlying genotypes. These experiments of nature provide a unique insight into the quantitative regulation of human immunity.
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Affiliation(s)
- Bertrand Boisson
- St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, NY 10065, USA
| | - Pierre Quartier
- Paris Descartes University, Imagine Institute, Paris 75015, France
- Pediatric Hematology-Immunology and Rheumatology Unit, Necker Hospital for Sick Children, Paris 75015, France
| | - Jean-Laurent Casanova
- St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, NY 10065, USA
- Paris Descartes University, Imagine Institute, Paris 75015, France
- Pediatric Hematology-Immunology and Rheumatology Unit, Necker Hospital for Sick Children, Paris 75015, France
- Howard Hughes Medical Institute, New York, NY 10065, USA
- Laboratory of Human Genetics of Infectious Diseases, Necker Branch, INSERM U1163, Necker Hospital for Sick Children, Paris 75015, France
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21
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Corneth OBJ, Klein Wolterink RGJ, Hendriks RW. BTK Signaling in B Cell Differentiation and Autoimmunity. Curr Top Microbiol Immunol 2015; 393:67-105. [PMID: 26341110 DOI: 10.1007/82_2015_478] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Since the original identification of Bruton's tyrosine kinase (BTK) as the gene defective in the primary immunodeficiency X-linked agammaglobulinemia (XLA) in 1993, our knowledge on the physiological function of BTK has expanded impressively. In this review, we focus on the role of BTK during B cell differentiation in vivo, both in the regulation of expansion and in the developmental progression of pre-B cells in the bone marrow and as a crucial signal transducer of signals downstream of the IgM or IgG B cell antigen receptor (BCR) in mature B cells governing proliferation, survival, and differentiation. In particular, we highlight BTK function in B cells in the context of host defense and autoimmunity. Small-molecule inhibitors of BTK have very recently shown impressive anti-tumor activity in clinical studies in patients with various B cell malignancies. Since promising effects of BTK inhibition were also seen in experimental animal models for lupus and rheumatoid arthritis, BTK may be a good target for controlling autoreactive B cells in patients with systemic autoimmune disease.
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Affiliation(s)
- Odilia B J Corneth
- Department of Pulmonary Medicine, Erasmus MC Rotterdam, Room Ee2251a, PO Box 2040, NL 3000, CA, Rotterdam, The Netherlands
| | - Roel G J Klein Wolterink
- Department of Pulmonary Medicine, Erasmus MC Rotterdam, Room Ee2251a, PO Box 2040, NL 3000, CA, Rotterdam, The Netherlands
| | - Rudi W Hendriks
- Department of Pulmonary Medicine, Erasmus MC Rotterdam, Room Ee2251a, PO Box 2040, NL 3000, CA, Rotterdam, The Netherlands.
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