1
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Mina ED, Jackson KJL, Crawford AJI, Faulks ML, Pathmanandavel K, Acquarola N, O'Sullivan M, Kerre T, Naesens L, Claes K, Goodnow CC, Haerynck F, Kracker S, Meyts I, D'Orsogna LJ, Ma CS, Tangye SG. A Novel Heterozygous Variant in AICDA Impairs Ig Class Switching and Somatic Hypermutation in Human B Cells and is Associated with Autosomal Dominant HIGM2 Syndrome. J Clin Immunol 2024; 44:66. [PMID: 38363477 PMCID: PMC10873450 DOI: 10.1007/s10875-024-01665-1] [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: 09/24/2023] [Accepted: 01/21/2024] [Indexed: 02/17/2024]
Abstract
B cells and their secreted antibodies are fundamental for host-defense against pathogens. The generation of high-affinity class switched antibodies results from both somatic hypermutation (SHM) of the immunoglobulin (Ig) variable region genes of the B-cell receptor and class switch recombination (CSR) which alters the Ig heavy chain constant region. Both of these processes are initiated by the enzyme activation-induced cytidine deaminase (AID), encoded by AICDA. Deleterious variants in AICDA are causal of hyper-IgM syndrome type 2 (HIGM2), a B-cell intrinsic primary immunodeficiency characterised by recurrent infections and low serum IgG and IgA levels. Biallelic variants affecting exons 2, 3 or 4 of AICDA have been identified that impair both CSR and SHM in patients with autosomal recessive HIGM2. Interestingly, B cells from patients with autosomal dominant HIGM2, caused by heterozygous variants (V186X, R190X) located in AICDA exon 5 encoding the nuclear export signal (NES) domain, show abolished CSR but variable SHM. We herein report the immunological and functional phenotype of two related patients presenting with common variable immunodeficiency who were found to have a novel heterozygous variant in AICDA (L189X). This variant led to a truncated AID protein lacking the last 10 amino acids of the NES at the C-terminal domain. Interestingly, patients' B cells carrying the L189X variant exhibited not only greatly impaired CSR but also SHM in vivo, as well as CSR and production of IgG and IgA in vitro. Our findings demonstrate that the NES domain of AID can be essential for SHM, as well as for CSR, thereby refining the correlation between AICDA genotype and SHM phenotype as well as broadening our understanding of the pathophysiology of HIGM disorders.
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Affiliation(s)
- Erika Della Mina
- Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, NSW, 2010, Australia
- School of Clinical Medicine, Faculty of Medicine and Health, UNSW Sydney, Sydney, Australia
| | - Katherine J L Jackson
- Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, NSW, 2010, Australia
| | - Alexander J I Crawford
- Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, NSW, 2010, Australia
| | - Megan L Faulks
- Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, NSW, 2010, Australia
| | - Karrnan Pathmanandavel
- Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, NSW, 2010, Australia
- School of Clinical Medicine, Faculty of Medicine and Health, UNSW Sydney, Sydney, Australia
| | - Nicolino Acquarola
- Department of Clinical Immunology and PathWest, Fiona Stanley Hospital, Murdoch, WA, Australia
| | - Michael O'Sullivan
- Department of Clinical Immunology and PathWest, Fiona Stanley Hospital, Murdoch, WA, Australia
- Department of Immunology, Perth Children's Hospital, Perth, WA, Australia
| | - Tessa Kerre
- Department of Hematology, Department of Internal Medicine and Pediatrics, Ghent University, Ghent, Belgium
- Center for Primary Immunodeficiency Ghent (CPIG), Jeffrey Modell Diagnosis and Research Center, ERN Rita Network Center, Ghent University Hospital, Ghent, Belgium
| | - Leslie Naesens
- Center for Primary Immunodeficiency Ghent (CPIG), Jeffrey Modell Diagnosis and Research Center, ERN Rita Network Center, Ghent University Hospital, Ghent, Belgium
- Primary Immunodeficiency Research Lab, Department of Internal Medicine and Pediatrics, Ghent University, Ghent, Belgium
| | - Karlien Claes
- Center for Primary Immunodeficiency Ghent (CPIG), Jeffrey Modell Diagnosis and Research Center, ERN Rita Network Center, Ghent University Hospital, Ghent, Belgium
- Primary Immunodeficiency Research Lab, Department of Internal Medicine and Pediatrics, Ghent University, Ghent, Belgium
| | - Christopher C Goodnow
- Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, NSW, 2010, Australia
- School of Clinical Medicine, Faculty of Medicine and Health, UNSW Sydney, Sydney, Australia
| | - Filomeen Haerynck
- Center for Primary Immunodeficiency Ghent (CPIG), Jeffrey Modell Diagnosis and Research Center, ERN Rita Network Center, Ghent University Hospital, Ghent, Belgium
- Primary Immunodeficiency Research Lab, Department of Internal Medicine and Pediatrics, Ghent University, Ghent, Belgium
| | - Sven Kracker
- Laboratory of Human Lymphohematopoiesis, INSERM UMR 1163, Imagine Institute, 75015, Paris, France
- Université Paris Cité, 75015, Paris, France
| | - Isabelle Meyts
- Inborn Errors of Immunity, Department of Microbiology, Immunology and Transplantation, KU Leuven, Louvain, Belgium
- Pediatric Immunodeficiency, Department of Pediatrics, University Hospitals Leuven, Louvain, Belgium
| | - Lloyd J D'Orsogna
- Department of Clinical Immunology and PathWest, Fiona Stanley Hospital, Murdoch, WA, Australia
- School of Medicine, University of Western Australia, Nedlands, WA, Australia
| | - Cindy S Ma
- Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, NSW, 2010, Australia
- School of Clinical Medicine, Faculty of Medicine and Health, UNSW Sydney, Sydney, Australia
| | - Stuart G Tangye
- Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, NSW, 2010, Australia.
- School of Clinical Medicine, Faculty of Medicine and Health, UNSW Sydney, Sydney, Australia.
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2
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da Silva-Buttkus P, Spielmann N, Klein-Rodewald T, Schütt C, Aguilar-Pimentel A, Amarie OV, Becker L, Calzada-Wack J, Garrett L, Gerlini R, Kraiger M, Leuchtenberger S, Östereicher MA, Rathkolb B, Sanz-Moreno A, Stöger C, Hölter SM, Seisenberger C, Marschall S, Fuchs H, Gailus-Durner V, Hrabě de Angelis M. Knockout mouse models as a resource for the study of rare diseases. Mamm Genome 2023; 34:244-261. [PMID: 37160609 PMCID: PMC10290595 DOI: 10.1007/s00335-023-09986-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 03/07/2023] [Indexed: 05/11/2023]
Abstract
Rare diseases (RDs) are a challenge for medicine due to their heterogeneous clinical manifestations and low prevalence. There is a lack of specific treatments and only a few hundred of the approximately 7,000 RDs have an approved regime. Rapid technological development in genome sequencing enables the mass identification of potential candidates that in their mutated form could trigger diseases but are often not confirmed to be causal. Knockout (KO) mouse models are essential to understand the causality of genes by allowing highly standardized research into the pathogenesis of diseases. The German Mouse Clinic (GMC) is one of the pioneers in mouse research and successfully uses (preclinical) data obtained from single-gene KO mutants for research into monogenic RDs. As part of the International Mouse Phenotyping Consortium (IMPC) and INFRAFRONTIER, the pan-European consortium for modeling human diseases, the GMC expands these preclinical data toward global collaborative approaches with researchers, clinicians, and patient groups.Here, we highlight proprietary genes that when deleted mimic clinical phenotypes associated with known RD targets (Nacc1, Bach2, Klotho alpha). We focus on recognized RD genes with no pre-existing KO mouse models (Kansl1l, Acsf3, Pcdhgb2, Rabgap1, Cox7a2) which highlight novel phenotypes capable of optimizing clinical diagnosis. In addition, we present genes with intriguing phenotypic data (Zdhhc5, Wsb2) that are not presently associated with known human RDs.This report provides comprehensive evidence for genes that when deleted cause differences in the KO mouse across multiple organs, providing a huge translational potential for further understanding monogenic RDs and their clinical spectrum. Genetic KO studies in mice are valuable to further explore the underlying physiological mechanisms and their overall therapeutic potential.
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Affiliation(s)
- Patricia da Silva-Buttkus
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, Neuherberg, Germany
| | - Nadine Spielmann
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, Neuherberg, Germany
| | - Tanja Klein-Rodewald
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, Neuherberg, Germany
| | - Christine Schütt
- Institute of Experimental Genetics, Applied Computational Biology, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, Neuherberg, Germany
| | - Antonio Aguilar-Pimentel
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, Neuherberg, Germany
| | - Oana V Amarie
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, Neuherberg, Germany
| | - Lore Becker
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, Neuherberg, Germany
| | - Julia Calzada-Wack
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, Neuherberg, Germany
| | - Lillian Garrett
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, Neuherberg, Germany
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, Neuherberg, Germany
| | - Raffaele Gerlini
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, Neuherberg, Germany
| | - Markus Kraiger
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, Neuherberg, Germany
| | - Stefanie Leuchtenberger
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, Neuherberg, Germany
| | - Manuela A Östereicher
- Institute of Experimental Genetics, Applied Computational Biology, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, Neuherberg, Germany
| | - Birgit Rathkolb
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, Neuherberg, Germany
- German Center for Diabetes Research (DZD), Ingolstaedter Landstrasse 1, 85764, Neuherberg, Germany
- Institute of Molecular Animal Breeding and Biotechnology, Gene Center, Ludwig-Maximilians-Universität München, Feodor-Lynen Strasse 25, 81377, Munich, Germany
| | - Adrián Sanz-Moreno
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, Neuherberg, Germany
| | - Claudia Stöger
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, Neuherberg, Germany
| | - Sabine M Hölter
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, Neuherberg, Germany
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, Neuherberg, Germany
| | - Claudia Seisenberger
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, Neuherberg, Germany
| | - Susan Marschall
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, Neuherberg, Germany
| | - Helmut Fuchs
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, Neuherberg, Germany
| | - Valerie Gailus-Durner
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, Neuherberg, Germany
| | - Martin Hrabě de Angelis
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, Neuherberg, Germany.
- German Center for Diabetes Research (DZD), Ingolstaedter Landstrasse 1, 85764, Neuherberg, Germany.
- Chair of Experimental Genetics, TUM School of Life Sciences, Technische Universität München, Alte Akademie 8, 85354, Freising, Germany.
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3
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Sadeghalvad M, Rezaei N. Immunodeficiencies. Clin Immunol 2023. [DOI: 10.1016/b978-0-12-818006-8.00004-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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4
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Raymond LS, Leiding J, Forbes-Satter LR. Diagnostic Modalities in Primary Immunodeficiency. Clin Rev Allergy Immunol 2022; 63:90-98. [PMID: 35290615 DOI: 10.1007/s12016-022-08933-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/22/2022] [Indexed: 01/12/2023]
Abstract
As the field of inborn errors of immunity expands, providers continually update and fine-tune their diagnostic approach and selection of testing modalities to increase diagnostic accuracy. Here, we first describe a mechanistic consideration of laboratory testing, highlighting both benefits and drawbacks of currently clinically available testing modalities. Next, we provide methods in evaluation of patients presenting with concern for inborn errors of immunity as defined by the International Union of Immunological Societies 2019 phenotypic categories: primary antibody deficiencies, cellular and humoral immune deficiency, disorders of the innate immune system, and syndrome-associated and primary immune regulation disorders (PIRDs). Using the suggested approach in this paper as a roadmap highlights the importance of thorough history taking and physical examination as the foundation to guide further diagnostic tests. This is followed by enumeration and functional testing. Finally, to determine the underlying molecular etiology-specific genetic panels, chromosomal microarrays, and broad genetic testing (whole exome sequencing or whole genome sequencing) are available.
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Affiliation(s)
- Loveita S Raymond
- Department of Medicine, Baylor College of Medicine, Houston, USA.,William T. Shearer Center for Human Immunobiology, Texas Children's Hospital, Houston, USA
| | - Jennifer Leiding
- Department of Pediatrics, John's Hopkins University, All Children's Hospital, Baltimore, USA
| | - Lisa R Forbes-Satter
- Department of Medicine, Baylor College of Medicine, Houston, USA. .,Department of Pediatrics, John's Hopkins University, All Children's Hospital, Baltimore, USA. .,William T. Shearer Center for Human Immunobiology, Texas Children's Hospital, Houston, USA.
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5
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Kermode W, De Santis D, Truong L, Della Mina E, Salman S, Thompson G, Nolan D, Loh R, Mallon D, Mclean-Tooke A, John M, Tangye SG, O'Sullivan M, D'Orsogna LJ. A Novel Targeted Amplicon Next-Generation Sequencing Gene Panel for the Diagnosis of Common Variable Immunodeficiency Has a High Diagnostic Yield: Results from the Perth CVID Cohort Study. J Mol Diagn 2022; 24:586-599. [PMID: 35570134 DOI: 10.1016/j.jmoldx.2022.02.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 12/23/2021] [Accepted: 02/09/2022] [Indexed: 11/18/2022] Open
Abstract
With the advent of next-generation sequencing (NGS), monogenic forms of common variable immunodeficiency (CVID) have been increasingly described. Our study aimed to identify disease-causing variants in a Western Australian CVID cohort using a novel targeted NGS panel. Targeted amplicon NGS was performed on 22 unrelated subjects who met the formal European Society for Immunodeficiencies-Pan-American Group for Immunodeficiency diagnostic criteria for CVID and had at least one of the following additional criteria: disease onset at age <18 years, autoimmunity, low memory B lymphocytes, family history, and/or history of lymphoproliferation. Candidate variants were assessed by in silico predictions of deleteriousness, comparison to the literature, and classified according to the American College of Medical Genetics and Genomics-Association for Molecular Pathology criteria. All detected genetic variants were verified independently by an external laboratory, and additional functional studies were performed if required. Pathogenic or likely pathogenic variants were detected in 6 of 22 (27%) patients. Monoallelic variants of uncertain significance were also identified in a further 4 of 22 patients (18%). Pathogenic variants, likely pathogenic variants, or variants of uncertain significance were found in TNFRSF13B, TNFRSF13C, ICOS, AICDA, IL21R, NFKB2, and CD40LG, including novel variants and variants with unexpected inheritance pattern. Targeted amplicon NGS is an effective tool to identify monogenic disease-causing variants in CVID, and is comparable or superior to other NGS methods. Moreover, targeted amplicon NGS identified patients who may benefit from targeted therapeutic strategies and had important implications for family members.
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Affiliation(s)
- William Kermode
- School of Medicine, University of Western Australia, Perth, Western Australia, Australia
| | - Dianne De Santis
- School of Medicine, University of Western Australia, Perth, Western Australia, Australia; Department of Clinical Immunology and PathWest, Fiona Stanley Hospital, Perth, Western Australia, Australia
| | - Linh Truong
- Department of Clinical Immunology and PathWest, Fiona Stanley Hospital, Perth, Western Australia, Australia
| | - Erika Della Mina
- Immunology and Immunodeficiency Laboratory, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia; St Vincent's Clinical School, Faculty of Medicine, University of New South Wales Sydney, Kensington, New South Wales, Australia
| | - Sam Salman
- Department of Clinical Immunology and PathWest, Queen Elizabeth II Medical Centre, Perth, Western Australia, Australia
| | - Grace Thompson
- Department of Clinical Immunology and PathWest, Queen Elizabeth II Medical Centre, Perth, Western Australia, Australia
| | - David Nolan
- Department of Clinical Immunology, Royal Perth Hospital, Perth, Western Australia, Australia
| | - Richard Loh
- Department of Immunology, Perth Children's Hospital, Perth, Western Australia, Australia
| | - Dominic Mallon
- Department of Clinical Immunology and PathWest, Fiona Stanley Hospital, Perth, Western Australia, Australia
| | - Andrew Mclean-Tooke
- Department of Clinical Immunology and PathWest, Queen Elizabeth II Medical Centre, Perth, Western Australia, Australia
| | - Mina John
- Department of Clinical Immunology, Royal Perth Hospital, Perth, Western Australia, Australia; Institute for Immunology and Infectious Diseases, Murdoch University, Perth, Western Australia, Australia
| | - Stuart G Tangye
- Immunology and Immunodeficiency Laboratory, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia; St Vincent's Clinical School, Faculty of Medicine, University of New South Wales Sydney, Kensington, New South Wales, Australia
| | - Michael O'Sullivan
- Department of Clinical Immunology and PathWest, Fiona Stanley Hospital, Perth, Western Australia, Australia; Department of Immunology, Perth Children's Hospital, Perth, Western Australia, Australia
| | - Lloyd J D'Orsogna
- School of Medicine, University of Western Australia, Perth, Western Australia, Australia; Department of Clinical Immunology and PathWest, Fiona Stanley Hospital, Perth, Western Australia, Australia.
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6
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Della Mina E, Tangye SG. Atypical Autosomal Recessive AID Deficiency-Yet Another Piece of the Hyper-IgM Puzzle. J Clin Immunol 2022; 42:713-715. [PMID: 35332417 DOI: 10.1007/s10875-022-01255-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 03/15/2022] [Indexed: 11/26/2022]
Affiliation(s)
- Erika Della Mina
- Immunology and Immunodeficiency Laboratory, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, New South Wales, 2010, Australia
- St. Vincent's Clinical School, UNSW Sydney, Darlinghurst, New South Wales, 2010, Australia
| | - Stuart G Tangye
- Immunology and Immunodeficiency Laboratory, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, New South Wales, 2010, Australia.
- St. Vincent's Clinical School, UNSW Sydney, Darlinghurst, New South Wales, 2010, Australia.
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7
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Xie X, Gan T, Rao B, Zhang W, Panchakshari RA, Yang D, Ji X, Cao Y, Alt FW, Meng FL, Hu J. C-terminal deletion-induced condensation sequesters AID from IgH targets in immunodeficiency. EMBO J 2022; 41:e109324. [PMID: 35471583 PMCID: PMC9156971 DOI: 10.15252/embj.2021109324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 04/07/2022] [Accepted: 04/08/2022] [Indexed: 11/09/2022] Open
Abstract
In activated B cells, activation-induced cytidine deaminase (AID) generates programmed DNA lesions required for antibody class switch recombination (CSR), which may also threaten genome integrity. AID dynamically shuttles between cytoplasm and nucleus, and the majority stays in the cytoplasm due to active nuclear export mediated by its C-terminal peptide. In immunodeficient-patient cells expressing mutant AID lacking its C-terminus, a catalytically active AID-delC protein accumulates in the nucleus but nevertheless fails to support CSR. To resolve this apparent paradox, we dissected the function of AID-delC proteins in the CSR process and found that they cannot efficiently target antibody genes. We demonstrate that AID-delC proteins form condensates both in vivo and in vitro, dependent on its N-terminus and on a surface arginine-rich patch. Co-expression of AID-delC and wild-type AID leads to an unbalanced nuclear AID-delC/AID ratio, with AID-delC proteins able to trap wild-type AID in condensates, resulting in a dominant-negative phenotype that could contribute to immunodeficiency. The co-condensation model of mutant and wild-type proteins could be an alternative explanation for the dominant-negative effect in genetic disorders.
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Affiliation(s)
- Xia Xie
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Tingting Gan
- The MOE Key Laboratory of Cell Proliferation and Differentiation, Genome Editing Research Center, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Bing Rao
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Weiwei Zhang
- The MOE Key Laboratory of Cell Proliferation and Differentiation, Genome Editing Research Center, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Rohit A Panchakshari
- Program in Cellular and Molecular Medicine, Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Dingpeng Yang
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Xiong Ji
- The MOE Key Laboratory of Cell Proliferation and Differentiation, Genome Editing Research Center, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Yu Cao
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Frederick W Alt
- Program in Cellular and Molecular Medicine, Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Fei-Long Meng
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Jiazhi Hu
- The MOE Key Laboratory of Cell Proliferation and Differentiation, Genome Editing Research Center, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
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8
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Smith T, Cunningham-Rundles C. Primary B-cell immunodeficiencies. Hum Immunol 2018; 80:351-362. [PMID: 30359632 DOI: 10.1016/j.humimm.2018.10.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 10/05/2018] [Accepted: 10/21/2018] [Indexed: 12/13/2022]
Abstract
Primary B-cell immunodeficiencies refer to diseases resulting from impaired antibody production due to either molecular defects intrinsic to B-cells or a failure of interaction between B-cells and T-cells. Patients typically have recurrent infections and can vary with presentation and complications depending upon where the defect has occurred in B-cell development or the degree of functional impairment. In this review, we describe B-cell specific immune defects categorized by presence or absence of peripheral B-cells, immunoglobulins isotypes and evidence of antibody impairment.
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Affiliation(s)
- Tukisa Smith
- Division of Allergy and Clinical Immunology, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, New York, NY 10029-6574, United States; The Rockefeller University, Laboratory of Biochemical Genetics and Metabolism, 1230 York Avenue, Box 179, New York, NY 10065, United States.
| | - Charlotte Cunningham-Rundles
- Division of Allergy and Clinical Immunology, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, New York, NY 10029-6574, United States.
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9
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Jhamnani RD, Nunes-Santos CJ, Bergerson J, Rosenzweig SD. Class-Switch Recombination (CSR)/Hyper-IgM (HIGM) Syndromes and Phosphoinositide 3-Kinase (PI3K) Defects. Front Immunol 2018; 9:2172. [PMID: 30319630 PMCID: PMC6168630 DOI: 10.3389/fimmu.2018.02172] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 09/03/2018] [Indexed: 11/13/2022] Open
Abstract
Antibody production and function represent an essential part of the immune response, particularly in fighting bacterial and viral infections. Multiple immunological phenotypes can result in dysregulation of the immune system humoral compartment, including class-switch recombination (CSR) defects associated with hyper-IgM (HIGM) syndromes. The CSR/HIGM syndromes are defined by the presence of normal or elevated plasma IgM levels in the context of low levels of switched IgG, IgA, and IgE isotypes. Recently described autosomal dominant gain-of-function (GOF) mutations in PIK3CD and PIK3R1 cause combined immunodeficiencies that can also present as CSR/HIGM defects. These defects, their pathophysiology and derived clinical manifestations are described in depth. Previously reported forms of CSR/HIGM syndromes are briefly reviewed and compared to the phosphoinositide 3-kinase (PI3K) pathway defects. Diseases involving the PI3K pathway represent a distinctive subset of CSR/HIGM syndromes, presenting with their own characteristic clinical and laboratory attributes as well as individual therapeutic approaches.
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Affiliation(s)
- Rekha D Jhamnani
- Allergy and Immunology Fellowship Program, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Cristiane J Nunes-Santos
- Immunology Service, Department of Laboratory Medicine, National Institutes of Health Clinical Center, National Institutes of Health, Bethesda, MD, United States.,Instituto da Crianca, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - Jenna Bergerson
- Laboratory of Clinical Immunology and Microbiology, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Sergio D Rosenzweig
- Immunology Service, Department of Laboratory Medicine, National Institutes of Health Clinical Center, National Institutes of Health, Bethesda, MD, United States
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10
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Avery DT, Kane A, Nguyen T, Lau A, Nguyen A, Lenthall H, Payne K, Shi W, Brigden H, French E, Bier J, Hermes JR, Zahra D, Sewell WA, Butt D, Elliott M, Boztug K, Meyts I, Choo S, Hsu P, Wong M, Berglund LJ, Gray P, O'Sullivan M, Cole T, Holland SM, Ma CS, Burkhart C, Corcoran LM, Phan TG, Brink R, Uzel G, Deenick EK, Tangye SG. Germline-activating mutations in PIK3CD compromise B cell development and function. J Exp Med 2018; 215:2073-2095. [PMID: 30018075 PMCID: PMC6080914 DOI: 10.1084/jem.20180010] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 05/15/2018] [Accepted: 06/20/2018] [Indexed: 11/04/2022] Open
Abstract
Gain-of-function (GOF) mutations in PIK3CD, encoding the p110δ subunit of phosphatidylinositide 3-kinase (PI3K), cause a primary immunodeficiency. Affected individuals display impaired humoral immune responses following infection or immunization. To establish mechanisms underlying these immune defects, we studied a large cohort of patients with PIK3CD GOF mutations and established a novel mouse model using CRISPR/Cas9-mediated gene editing to introduce a common pathogenic mutation in Pik3cd In both species, hyperactive PI3K severely affected B cell development and differentiation in the bone marrow and the periphery. Furthermore, PI3K GOF B cells exhibited intrinsic defects in class-switch recombination (CSR) due to impaired induction of activation-induced cytidine deaminase (AID) and failure to acquire a plasmablast gene signature and phenotype. Importantly, defects in CSR, AID expression, and Ig secretion were restored by leniolisib, a specific p110δ inhibitor. Our findings reveal key roles for balanced PI3K signaling in B cell development and long-lived humoral immunity and memory and establish the validity of treating affected individuals with p110δ inhibitors.
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Affiliation(s)
- Danielle T Avery
- Immunology Division, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
| | - Alisa Kane
- Immunology Division, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia.,St. Vincent's Clinical School, University of New South Wales (UNSW), New South Wales, Australia.,Department of Immunology and Allergy, Liverpool Hospital, Liverpool, New South Wales, Australia.,South Western Sydney Clinical School, UNSW Sydney, Liverpool, New South Wales, Australia.,Clinical Immunogenomics Research Consortia Australia (CIRCA), Sydney, New South Wales, Australia
| | - Tina Nguyen
- Immunology Division, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia.,St. Vincent's Clinical School, University of New South Wales (UNSW), New South Wales, Australia
| | - Anthony Lau
- Immunology Division, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia.,St. Vincent's Clinical School, University of New South Wales (UNSW), New South Wales, Australia
| | - Akira Nguyen
- Immunology Division, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia.,St. Vincent's Clinical School, University of New South Wales (UNSW), New South Wales, Australia
| | - Helen Lenthall
- Immunology Division, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
| | - Kathryn Payne
- Immunology Division, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
| | - Wei Shi
- Molecular Immunology and Bioinformatics Divisions, Walter & Eliza Hall Institute for Medical Research, Parkville, Victoria, Australia.,University of Melbourne, Parkville, Victoria, Australia
| | - Henry Brigden
- Immunology Division, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
| | - Elise French
- Immunology Division, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
| | - Julia Bier
- Immunology Division, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia.,St. Vincent's Clinical School, University of New South Wales (UNSW), New South Wales, Australia
| | - Jana R Hermes
- Immunology Division, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
| | - David Zahra
- Immunology Division, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
| | - William A Sewell
- Immunology Division, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia.,St. Vincent's Clinical School, University of New South Wales (UNSW), New South Wales, Australia.,Immunology Department, SydPath, St. Vincent's Hospital, Sydney, New South Wales, Australia
| | - Danyal Butt
- Immunology Division, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia.,St. Vincent's Clinical School, University of New South Wales (UNSW), New South Wales, Australia
| | - Michael Elliott
- Sydney Medical School, University of Sydney, Sydney, Australia.,Chris O'Brien Lifehouse Cancer Centre, Royal Prince Alfred Hospital, Sydney, Australia
| | - Kaan Boztug
- Ludwig Boltzmann Institute for Rare and Undiagnosed Diseases, Vienna, Austria.,CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria.,St. Anna Children's Hospital and Children's Cancer Research Institute, Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - Isabelle Meyts
- Department of Immunology and Microbiology, Childhood Immunology, Department of Pediatrics, University Hospitals Leuven and KU Leuven, Leuven, Belgium
| | - Sharon Choo
- Department of Allergy and Immunology, Royal Children's Hospital Melbourne, Victoria, Australia
| | - Peter Hsu
- Clinical Immunogenomics Research Consortia Australia (CIRCA), Sydney, New South Wales, Australia.,Children's Hospital at Westmead, New South Wales, Australia
| | - Melanie Wong
- Clinical Immunogenomics Research Consortia Australia (CIRCA), Sydney, New South Wales, Australia.,Children's Hospital at Westmead, New South Wales, Australia
| | - Lucinda J Berglund
- Clinical Immunogenomics Research Consortia Australia (CIRCA), Sydney, New South Wales, Australia.,Immunopathology Department, Westmead Hospital, Westmead, New South Wales, Australia.,Faculty of Medicine, University of Sydney, Sydney, New South Wales, Australia
| | - Paul Gray
- Clinical Immunogenomics Research Consortia Australia (CIRCA), Sydney, New South Wales, Australia.,University of New South Wales School of Women's and Children's Health, New South Wales, Australia
| | - Michael O'Sullivan
- Department of Immunology and Allergy, Princess Margaret Hospital, Subiaco, Western Australia, Australia
| | - Theresa Cole
- Department of Allergy and Immunology, Royal Children's Hospital Melbourne, Victoria, Australia
| | - Steven M Holland
- Laboratory of Clinical Immunology and Microbiology, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD
| | - Cindy S Ma
- Immunology Division, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia.,St. Vincent's Clinical School, University of New South Wales (UNSW), New South Wales, Australia.,Clinical Immunogenomics Research Consortia Australia (CIRCA), Sydney, New South Wales, Australia
| | - Christoph Burkhart
- Novartis Institutes for BioMedical Research, Novartis Pharma AG, Basel, Switzerland
| | - Lynn M Corcoran
- Molecular Immunology and Bioinformatics Divisions, Walter & Eliza Hall Institute for Medical Research, Parkville, Victoria, Australia.,University of Melbourne, Parkville, Victoria, Australia
| | - Tri Giang Phan
- Immunology Division, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia.,St. Vincent's Clinical School, University of New South Wales (UNSW), New South Wales, Australia.,Clinical Immunogenomics Research Consortia Australia (CIRCA), Sydney, New South Wales, Australia
| | - Robert Brink
- Immunology Division, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia.,St. Vincent's Clinical School, University of New South Wales (UNSW), New South Wales, Australia.,Clinical Immunogenomics Research Consortia Australia (CIRCA), Sydney, New South Wales, Australia
| | - Gulbu Uzel
- Laboratory of Clinical Immunology and Microbiology, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD
| | - Elissa K Deenick
- Immunology Division, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia .,St. Vincent's Clinical School, University of New South Wales (UNSW), New South Wales, Australia.,Clinical Immunogenomics Research Consortia Australia (CIRCA), Sydney, New South Wales, Australia
| | - Stuart G Tangye
- Immunology Division, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia .,St. Vincent's Clinical School, University of New South Wales (UNSW), New South Wales, Australia.,Clinical Immunogenomics Research Consortia Australia (CIRCA), Sydney, New South Wales, Australia
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11
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The Antiviral and Cancer Genomic DNA Deaminase APOBEC3H Is Regulated by an RNA-Mediated Dimerization Mechanism. Mol Cell 2017; 69:75-86.e9. [PMID: 29290613 DOI: 10.1016/j.molcel.2017.12.010] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 10/25/2017] [Accepted: 12/13/2017] [Indexed: 01/23/2023]
Abstract
Human APOBEC3H and homologous single-stranded DNA cytosine deaminases are unique to mammals. These DNA-editing enzymes function in innate immunity by restricting the replication of viruses and transposons. APOBEC3H also contributes to cancer mutagenesis. Here, we address the fundamental nature of RNA in regulating human APOBEC3H activities. APOBEC3H co-purifies with RNA as an inactive protein, and RNase A treatment enables strong DNA deaminase activity. RNA-binding-defective mutants demonstrate clear separation of function by becoming DNA hypermutators. Biochemical and crystallographic data demonstrate a mechanism in which double-stranded RNA mediates enzyme dimerization. Additionally, APOBEC3H separation-of-function mutants show that RNA binding is required for cytoplasmic localization, packaging into HIV-1 particles, and antiviral activity. Overall, these results support a model in which structured RNA negatively regulates the potentially harmful DNA deamination activity of APOBEC3H while, at the same time, positively regulating its antiviral activity.
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12
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de la Morena MT. Clinical Phenotypes of Hyper-IgM Syndromes. THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY-IN PRACTICE 2017; 4:1023-1036. [PMID: 27836054 DOI: 10.1016/j.jaip.2016.09.013] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 09/21/2016] [Accepted: 09/23/2016] [Indexed: 02/05/2023]
Abstract
The primary immunodeficiency (PID) diseases comprise a heterogeneous group of inherited disorders of immune function. Technical advancements in whole-genome, whole-exome, and RNA-sequencing have seen the explosion of genetic discoveries in the field of PIDs. The present review aims to focus on a group of immunodeficiency disorders associated with elevated levels of IgM (hyper IgM; HIGM) and provides a clinical differential diagnosis. Most patients present for evaluation of immunodeficiency due to recurrent infections, and laboratory studies show either a clear isolated elevation of serum immunoglobulin M (IgM) with low or absent IgG, IgA, and IgE. Alternatively, IgM levels may be normal or moderately elevated while other serum immunoglobulins are reported below the norms for age but not absent. Mechanistically, these disorders are recognized as defects in immunoglobulin (Ig) class switch recombination (CSR). Importantly, to safeguard genetic stability, CSR utilizes elements of the DNA repair machinery including multi-protein complexes involved in mismatch repair (MMR). Therefore, it is not uncommon for defects in the DNA repair machinery, to present with laboratory findings of HIGM. This review will discuss clinical phenotypes associated with congenital defects associated with HIGM. Clinical manifestations, relevant immunologic testing, inheritance pattern, molecular diagnosis, presumed pathogenesis, and OMIM number, when annotated are compiled. Accepted therapeutic options, when available, are reviewed for each condition discussed.
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Affiliation(s)
- M Teresa de la Morena
- Division of Allergy and Immunology, Department of Pediatrics and Internal Medicine, University of Texas, Southwestern Medical Center, Dallas, Texas.
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13
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Morio T. Recent advances in the study of immunodeficiency and DNA damage response. Int J Hematol 2017; 106:357-365. [PMID: 28550350 DOI: 10.1007/s12185-017-2263-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 05/17/2017] [Indexed: 12/13/2022]
Abstract
DNA breaks can be induced by exogenous stimuli or by endogenous stress, but are also generated during recombination of V, D, and J genes (V(D)J recombination), immunoglobulin class switch recombination (CSR). Among various DNA breaks generated, DNA double strand break (DSB) is the most deleterious one. DNA damage response (DDR) is initiated when DSBs are detected, leading to DNA break repair by non-homologous end joining (NHEJ). The process is critically important for the generation of diversity for foreign antigens; and failure to exert DNA repair leads to immunodeficiency such as severe combined immunodeficiency and hyper-IgM syndrome. In V(D)J recombination, DSBs are induced by RAG1/2; and generated post-cleavage hairpins are resolved by Artemis/DNA-PKcs/KU70/KU80. DDR is initiated by ataxia-telangiectasia mutated as a master regulator together with MRE11/RAD50/NBS1 complex. Finally, DSBs are repaired by NHEJ. The defect of one of the molecules shows various degree of immunodeficiency and radiosensitivity. Upon CSR inducing signal, DSBs induced by activation-induced cytidine deaminase and endonucleases elicit DDR. Broken ends are repaired either by NHEJ or by mismatch repair system. Patients with radiosensitive SCID require hematopoietic cell transplantation as a curative therapy; but the procedures for eradication of recipient hematopoietic cells are often associated with severe toxicity.
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Affiliation(s)
- Tomohiro Morio
- Department of Pediatrics and Developmental Biology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
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14
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Fazel A, Kashef S, Aleyasin S, Harsini S, Karamizadeh Z, Zoghi S, Flores SK, Boztug K, Rezaei N. Novel AICDA mutation in a case of autosomal recessive hyper-IgM syndrome, growth hormone deficiency and autoimmunity. Allergol Immunopathol (Madr) 2017; 45:82-86. [PMID: 27789066 DOI: 10.1016/j.aller.2016.08.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 07/13/2016] [Accepted: 08/01/2016] [Indexed: 01/02/2023]
Abstract
BACKGROUND The Hyper-immunoglobulin M syndromes (HIGM) are a heterogeneous group of genetic disorders, which have been rarely reported to be associated with growth hormone deficiency (GHD). METHODS AND RESULTS A nine-year-old girl with recurrent urinary tract infections, diarrhoea, sinopulmonary infections, and failure to thrive since the age of six months had normal CD3+, CD4+, CD8+T lymphocytes, and CD19+B lymphocytes and natural killer (NK) cells, but extremely elevated IgM and significantly decreased IgG and IgA. In view of the patient's short stature, growth hormone evaluation was carried out and growth hormone deficiency established. The patient underwent Ig replacement therapy and received growth hormone therapy in addition to antibiotics and responded well. Furthermore, the patient developed benign cervical lymphadenopathy, as well as elevated erythrocyte sedimentation rate, positive autoantibodies to SSA-Ro, and severely dry eyes, which partially responded to both the punctate occlusion and systemic corticosteroids, at the age of seven years. Sequencing analysis of the exons from activation-induced cytidine deaminase (AICDA) gene revealed that the patient was homozygous for a single T to C transversion at position 455 in exon 4, which replaces a Valine with an Alanine. CONCLUSIONS To our knowledge, this is a new AICDA mutation, which has not been reported previously in HIGM. The mutation analysis could improve diagnosis of HIGM patients and also elaborating on the spectrum of AICDA mutations.
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Affiliation(s)
- A Fazel
- Allergy Research Center, Division of Pediatric Immunology and Allergy, Shiraz University of Medical Sciences, Shiraz, Iran
| | - S Kashef
- Allergy Research Center, Division of Pediatric Immunology and Allergy, Shiraz University of Medical Sciences, Shiraz, Iran.
| | - S Aleyasin
- Allergy Research Center, Division of Pediatric Immunology and Allergy, Shiraz University of Medical Sciences, Shiraz, Iran
| | - S Harsini
- Research Center for Immunodeficiencies, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran; Network of Immunity in Infection, Malignancy and Autoimmunity (NIIMA), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Z Karamizadeh
- Division of Pediatric Endocrinology, Shiraz University of Medical Sciences, Shiraz, Iran
| | - S Zoghi
- Network of Immunity in Infection, Malignancy and Autoimmunity (NIIMA), Universal Scientific Education and Research Network (USERN), Tehran, Iran; Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - S K Flores
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - K Boztug
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria; Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - N Rezaei
- Research Center for Immunodeficiencies, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran; Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Primary Immunodeficiency Diseases Network (PIDNet), Universal Scientific Education and Research Network (USERN), Sheffield, UK.
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15
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Almejún MB, Campos BC, Patiño V, Galicchio M, Zelazko M, Oleastro M, Oppezzo P, Danielian S. Noninfectious complications in patients with pediatric-onset common variable immunodeficiency correlated with defects in somatic hypermutation but not in class-switch recombination. J Allergy Clin Immunol 2016; 139:913-922. [PMID: 27713077 DOI: 10.1016/j.jaci.2016.08.030] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 08/03/2016] [Accepted: 08/10/2016] [Indexed: 11/17/2022]
Abstract
BACKGROUND Common variable immunodeficiency (CVID) is a heterogeneous syndrome characterized by impaired immunoglobulin production and usually presents with a normal quantity of peripheral B cells. Most attempts aiming to classify these patients have mainly been focused on T- or B-cell phenotypes and their ability to produce protective antibodies, but it is still a major challenge to find a suitable classification that includes the clinical and immunologic heterogeneity of these patients. OBJECTIVE In this study we evaluated the late stages of B-cell differentiation in a heterogeneous population of patients with pediatric-onset CVID to clinically correlate and assess their ability to perform somatic hypermutation (SHM), class-switch recombination (CSR), or both. METHODS We performed a previously reported assay, the restriction enzyme hotspot mutation assay (IgκREHMA), to evaluate in vivo SHM status. We amplified switch regions from genomic DNA to investigate the quality of the double-strand break repairs in the class-switch recombination process in vivo. We also tested the ability to generate immunoglobulin germline and circle transcripts and to upregulate the activation-induced cytidine deaminase gene through in vitro T-dependent and T-independent stimuli. RESULTS Our results showed that patients could be classified into 2 groups according to their degree of SHM alteration. This stratification showed a significant association between patients of group A, severe alteration, and the presence of noninfectious complications. Additionally, 60% of patients presented with increased microhomology use at switched regions. In vitro activation revealed that patients with CVID behaved heterogeneously in terms of responsiveness to T-dependent stimuli. CONCLUSIONS The correlation between noninfectious complications and SHM could be an important tool for physicians to further characterize patients with CVID. This categorization would help to improve elucidation of the complex mechanisms involved in B-cell differentiation pathways.
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Affiliation(s)
- María Belén Almejún
- Servicio de Immunología y Reumatología, Hospital Nacional de Pediatría Prof. Dr Juan P. Garrahan, Buenos Aires, Argentina.
| | - Bárbara Carolina Campos
- Coordinación de Laboratorio, Hospital Nacional de Pediatría Prof. Dr Juan P. Garrahan, Buenos Aires, Argentina
| | - Virginia Patiño
- Unidad de Proteínas Recombinantes, Instituto Pasteur, Montevideo, Uruguay
| | - Miguel Galicchio
- Hospital de Niños Víctor J. Vilela, Rosario, Santa Fé, Argentina
| | - Marta Zelazko
- Servicio de Immunología y Reumatología, Hospital Nacional de Pediatría Prof. Dr Juan P. Garrahan, Buenos Aires, Argentina
| | - Matías Oleastro
- Servicio de Immunología y Reumatología, Hospital Nacional de Pediatría Prof. Dr Juan P. Garrahan, Buenos Aires, Argentina
| | - Pablo Oppezzo
- Unidad de Proteínas Recombinantes, Instituto Pasteur, Montevideo, Uruguay
| | - Silvia Danielian
- Servicio de Immunología y Reumatología, Hospital Nacional de Pediatría Prof. Dr Juan P. Garrahan, Buenos Aires, Argentina
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16
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Aryan Z, Aghamohammadi A, Rezaei N. Toward the stratification and personalization of common variable immunodeficiency treatment. Expert Opin Orphan Drugs 2016. [DOI: 10.1080/21678707.2016.1205480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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17
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Enrichment of rare variants in population isolates: single AICDA mutation responsible for hyper-IgM syndrome type 2 in Finland. Eur J Hum Genet 2016; 24:1473-8. [PMID: 27142677 PMCID: PMC5027683 DOI: 10.1038/ejhg.2016.37] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 02/12/2016] [Accepted: 03/15/2016] [Indexed: 01/21/2023] Open
Abstract
Antibody class-switch recombination and somatic hypermutation critically depend on the function of activation-induced cytidine deaminase (AID). Rare variants in its gene AICDA have been reported to cause autosomal recessive AID deficiency (autosomal recessive hyper-IgM syndrome type 2 (HIGM2)). Exome sequencing of a multicase Finnish family with an HIGM2 phenotype identified a rare, homozygous, variant (c.416T>C, p.(Met139Thr)) in the AICDA gene, found to be significantly enriched in the Finnish population compared with other populations of European origin (38.56-fold, P<0.001). The population history of Finland, characterized by a restricted number of founders, isolation and several population bottlenecks, has caused enrichment of certain rare disease-causing variants and losses of others, as part of a phenomenon called the Finnish Disease Heritage. Accordingly, rare founder mutations cause the majority of observed Finnish cases in these mostly autosomal recessive disorders that consequently are more frequent in Finland than elsewhere. Screening of all currently known Finnish patients with an HIGM2 phenotype showed them to be homozygous for p.(Met139Thr). All the Finnish p.(Met139Thr) carriers with available data on their geographic descent originated from the eastern and northeastern parts of Finland. They were observed to share more of their genome identity by descent (IBD) than Finns in general (P<0.001), and they all carried a 207.5-kb ancestral haplotype containing the variant. In conclusion, the identified p.(Met139Thr) variant is significantly enriched in Finns and explains all thus far found AID deficiencies in Finland.
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18
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Mousallem T, Urban TJ, McSweeney KM, Kleinstein SE, Zhu M, Adeli M, Parrott RE, Roberts JL, Krueger B, Buckley RH, Goldstein DB. Clinical application of whole-genome sequencing in patients with primary immunodeficiency. J Allergy Clin Immunol 2015; 136:476-9.e6. [PMID: 25981738 DOI: 10.1016/j.jaci.2015.02.040] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Revised: 12/19/2014] [Accepted: 02/03/2015] [Indexed: 11/17/2022]
Affiliation(s)
- Talal Mousallem
- Departments of Internal Medicine and Pediatrics, Wake Forest School of Medicine, Winston-Salem, NC; Department of Pediatrics, Duke University Medical Center, Durham, NC.
| | - Thomas J Urban
- Center for Human Genome Variation, Duke University School of Medicine, Durham, NC; Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC
| | - K Melodi McSweeney
- Center for Human Genome Variation, Duke University School of Medicine, Durham, NC; Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC; Institute for Genomic Medicine, Columbia University Medical Center, New York, NY
| | - Sarah E Kleinstein
- Center for Human Genome Variation, Duke University School of Medicine, Durham, NC; Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC; Institute for Genomic Medicine, Columbia University Medical Center, New York, NY
| | - Mingfu Zhu
- Center for Human Genome Variation, Duke University School of Medicine, Durham, NC
| | | | - Roberta E Parrott
- Department of Pediatrics, Duke University Medical Center, Durham, NC
| | - Joseph L Roberts
- Department of Pediatrics, Duke University Medical Center, Durham, NC
| | - Brian Krueger
- Center for Human Genome Variation, Duke University School of Medicine, Durham, NC; Institute for Genomic Medicine, Columbia University Medical Center, New York, NY
| | - Rebecca H Buckley
- Department of Pediatrics, Duke University Medical Center, Durham, NC; Department of Immunology, Duke University School of Medicine, Durham, NC.
| | - David B Goldstein
- Center for Human Genome Variation, Duke University School of Medicine, Durham, NC; Institute for Genomic Medicine, Columbia University Medical Center, New York, NY
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19
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Kracker S, Di Virgilio M, Schwartzentruber J, Cuenin C, Forveille M, Deau MC, McBride KM, Majewski J, Gazumyan A, Seneviratne S, Grimbacher B, Kutukculer N, Herceg Z, Cavazzana M, Jabado N, Nussenzweig MC, Fischer A, Durandy A. An inherited immunoglobulin class-switch recombination deficiency associated with a defect in the INO80 chromatin remodeling complex. J Allergy Clin Immunol 2015; 135:998-1007.e6. [PMID: 25312759 PMCID: PMC4382329 DOI: 10.1016/j.jaci.2014.08.030] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Revised: 07/31/2014] [Accepted: 08/05/2014] [Indexed: 11/29/2022]
Abstract
BACKGROUND Immunoglobulin class-switch recombination defects (CSR-D) are rare primary immunodeficiencies characterized by impaired production of switched immunoglobulin isotypes and normal or elevated IgM levels. They are caused by impaired T:B cooperation or intrinsic B cell defects. However, many immunoglobulin CSR-Ds are still undefined at the molecular level. OBJECTIVE This study's objective was to delineate new causes of immunoglobulin CSR-Ds and thus gain further insights into the process of immunoglobulin class-switch recombination (CSR). METHODS Exome sequencing in 2 immunoglobulin CSR-D patients identified variations in the INO80 gene. Functional experiments were performed to assess the function of INO80 on immunoglobulin CSR. RESULTS We identified recessive, nonsynonymous coding variations in the INO80 gene in 2 patients affected by defective immunoglobulin CSR. Expression of wild-type INO80 in patients' fibroblastic cells corrected their hypersensitivity to high doses of γ-irradiation. In murine CH12-F3 cells, the INO80 complex accumulates at Sα and Eμ regions of the IgH locus, and downregulation of INO80 as well as its partners Reptin and Pontin impaired CSR. In addition, Reptin and Pontin were shown to interact with activation-induced cytidine deaminase. Finally, an abnormal separation of sister chromatids was observed upon INO80 downregulation in CH12-F3 cells, pinpointing its role in cohesin activity. CONCLUSION INO80 deficiency appears to be associated with defective immunoglobulin CSR. We propose that the INO80 complex modulates cohesin function that may be required during immunoglobulin switch region synapsis.
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Affiliation(s)
- Sven Kracker
- INSERM UMR 1163, The Human Lymphohematopoiesis Laboratory, Imagine Institute, Paris, France; Paris Descartes Sorbonne Paris Cité University, Imagine Institute, Paris, France
| | - Michela Di Virgilio
- Laboratory of Molecular Immunology, Howard Hughes Medical Institute, the Rockefeller University, New York, NY
| | - Jeremy Schwartzentruber
- Department of Human Genetics, McGill University and Genome Quebec Innovation Centre, Montreal, Quebec, Canada
| | - Cyrille Cuenin
- International Agency for Research on Cancer, F-69008 Lyon, Lyon, France
| | - Monique Forveille
- Center for Primary Immunodeficiencies, Hôpital Necker Enfants Malades, F-75015 Paris, Paris, France
| | - Marie-Céline Deau
- INSERM UMR 1163, The Human Lymphohematopoiesis Laboratory, Imagine Institute, Paris, France; Paris Descartes Sorbonne Paris Cité University, Imagine Institute, Paris, France
| | - Kevin M McBride
- Laboratory of Molecular Immunology, Howard Hughes Medical Institute, the Rockefeller University, New York, NY
| | - Jacek Majewski
- Department of Human Genetics, McGill University and Genome Quebec Innovation Centre, Montreal, Quebec, Canada
| | - Anna Gazumyan
- Laboratory of Molecular Immunology, Howard Hughes Medical Institute, the Rockefeller University, New York, NY
| | - Suranjith Seneviratne
- UCL Institute of Immunity and Transplantation, Royal Free London NHS Foundation Tust, London, United Kingdom
| | - Bodo Grimbacher
- UCL Institute of Immunity and Transplantation, Royal Free London NHS Foundation Tust, London, United Kingdom; Centre of Chronic Immunodeficiency, University Medical Center Freiburg and University of Freiburg, D-79106 Freiburg, Freiburg, Germany
| | - Necil Kutukculer
- Ege University Faculty of Medicine, Department of Pediatric Immunology, 35100 Bornova, Izmir, Turkey
| | - Zdenko Herceg
- International Agency for Research on Cancer, F-69008 Lyon, Lyon, France
| | - Marina Cavazzana
- INSERM UMR 1163, The Human Lymphohematopoiesis Laboratory, Imagine Institute, Paris, France; Paris Descartes Sorbonne Paris Cité University, Imagine Institute, Paris, France; Department of Biotherapy, AP-HP Hôpital Necker Enfants Malades, F-75015 Paris, Paris, France; Clinical Investigation Center (CIC)-Biotherapy GHU Ouest, INSERM-APHP (Assistance Publique des Hôpitaux de Paris), Paris, France
| | - Nada Jabado
- Department of Pediatrics, McGill University and McGill University Health Center, Montreal, Quebec, Canada
| | - Michel C Nussenzweig
- Laboratory of Molecular Immunology, Howard Hughes Medical Institute, the Rockefeller University, New York, NY
| | - Alain Fischer
- INSERM UMR 1163, The Human Lymphohematopoiesis Laboratory, Imagine Institute, Paris, France; Paris Descartes Sorbonne Paris Cité University, Imagine Institute, Paris, France; Department of Immunology and Hematology, Hôpital Necker Enfants Malades, F-75015 Paris, Paris, France; Collège de France, Paris, France
| | - Anne Durandy
- INSERM UMR 1163, The Human Lymphohematopoiesis Laboratory, Imagine Institute, Paris, France; Paris Descartes Sorbonne Paris Cité University, Imagine Institute, Paris, France; Department of Immunology and Hematology, Hôpital Necker Enfants Malades, F-75015 Paris, Paris, France.
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20
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Locke BA, Dasu T, Verbsky JW. Laboratory diagnosis of primary immunodeficiencies. Clin Rev Allergy Immunol 2014; 46:154-68. [PMID: 24569953 DOI: 10.1007/s12016-014-8412-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Primary immune deficiency disorders represent a highly heterogeneous group of disorders with an increased propensity to infections and other immune complications. A careful history to delineate the pattern of infectious organisms and other complications is important to guide the workup of these patients, but a focused laboratory evaluation is essential to the diagnosis of an underlying primary immunodeficiency. Initial workup of suspected immune deficiencies should include complete blood counts and serologic tests of immunoglobulin levels, vaccine titers, and complement levels, but these tests are often insufficient to make a diagnosis. Recent advancements in the understanding of the immune system have led to the development of novel immunologic assays to aid in the diagnosis of these disorders. Classically utilized to enumerate lymphocyte subsets, flow cytometric-based assays are increasingly utilized to test immune cell function (e.g., neutrophil oxidative burst, NK cytotoxicity), intracellular cytokine production (e.g., TH17 production), cellular signaling pathways (e.g., phosphor-STAT analysis), and protein expression (e.g., BTK, Foxp3). Genetic testing has similarly expanded greatly as more primary immune deficiencies are defined, and the use of mass sequencing technologies is leading to the identification of novel disorders. In order to utilize these complex assays in clinical care, one must have a firm understanding of the immunologic assay, how the results are interpreted, pitfalls in the assays, and how the test affects treatment decisions. This article will provide a systematic approach of the evaluation of a suspected primary immunodeficiency, as well as provide a comprehensive list of testing options and their results in the context of various disease processes.
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Affiliation(s)
- Bradley A Locke
- Department of Pediatrics, Division of Allergy and Clinical Immunology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
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21
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Dahlberg CIM, He M, Visnes T, Torres ML, Cortizas EM, Verdun RE, Westerberg LS, Severinson E, Ström L. A novel mouse model for the hyper-IgM syndrome: a spontaneous activation-induced cytidine deaminase mutation leading to complete loss of Ig class switching and reduced somatic hypermutation. THE JOURNAL OF IMMUNOLOGY 2014; 193:4732-8. [PMID: 25252954 DOI: 10.4049/jimmunol.1401242] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We describe a spontaneously derived mouse line that completely failed to induce Ig class switching in vitro and in vivo. The mice inherited abolished IgG serum titers in a recessive manner caused by a spontaneous G → A transition mutation in codon 112 of the aicda gene, leading to an arginine to histidine replacement (AID(R112H)). Ig class switching was completely reconstituted by expressing wild-type AID. Mice homozygous for AID(R112H) had peripheral B cell hyperplasia and large germinal centers in the absence of Ag challenge. Immunization with SRBCs elicited an Ag-specific IgG1 response in wild-type mice, whereas AID(R112H) mice failed to produce IgG1 and had reduced somatic hypermutation. The phenotype recapitulates the human hyper-IgM (HIGM) syndrome that is caused by point mutations in the orthologous gene in humans, and the AID(R112H) mutation is frequently found in HIGM patients. The AID(R112H) mouse model for HIGM provides a powerful and more precise tool than conventional knockout strategies.
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Affiliation(s)
- Carin I M Dahlberg
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Minghui He
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Torkild Visnes
- Department of Cell and Molecular Biology, Karolinska Institutet, SE-171 77 Stockholm, Sweden; and
| | - Magda Liz Torres
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Elena M Cortizas
- Division of Gerontology and Geriatric Medicine, Department of Medicine, Miller School of Medicine, University of Miami, Miami, FL 33136
| | - Ramiro E Verdun
- Division of Gerontology and Geriatric Medicine, Department of Medicine, Miller School of Medicine, University of Miami, Miami, FL 33136
| | - Lisa S Westerberg
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, SE-171 77 Stockholm, Sweden;
| | - Eva Severinson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden;
| | - Lena Ström
- Department of Cell and Molecular Biology, Karolinska Institutet, SE-171 77 Stockholm, Sweden; and
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22
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Aghamohammadi A, Mohammadinejad P, Abolhassani H, Mirminachi B, Movahedi M, Gharagozlou M, Parvaneh N, Zeiaee V, Mirsaeed-Ghazi B, Chavoushzadeh Z, Mahdaviani A, Mansouri M, Yousefzadegan S, Sharifi B, Zandieh F, Hedayat E, Nadjafi A, Sherkat R, Shakerian B, Sadeghi-Shabestari M, Farid Hosseini R, Jabbari-Azad F, Ahanchian H, Behmanesh F, Zandkarimi M, Shirkani A, Cheraghi T, Fayezi A, Mohammadzadeh I, Amin R, Aleyasin S, Moghtaderi M, Ghaffari J, Arshi S, Javahertrash N, Nabavi M, Bemanian MH, Shafiei A, Kalantari N, Ahmadiafshar A, Khazaei HA, Atarod L, Rezaei N. Primary Immunodeficiency Disorders in Iran: Update and New Insights from the Third Report of the National Registry. J Clin Immunol 2014; 34:478-90. [DOI: 10.1007/s10875-014-0001-z] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2013] [Accepted: 02/12/2014] [Indexed: 12/22/2022]
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23
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Activation induced deaminase C-terminal domain links DNA breaks to end protection and repair during class switch recombination. Proc Natl Acad Sci U S A 2014; 111:E988-97. [PMID: 24591601 DOI: 10.1073/pnas.1320486111] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Activation-induced deaminase (AID) triggers antibody class switch recombination (CSR) in B cells by initiating DNA double strand breaks that are repaired by nonhomologous end-joining pathways. A role for AID at the repair step is unclear. We show that specific inactivation of the C-terminal AID domain encoded by exon 5 (E5) allows very efficient deamination of the AID target regions but greatly impacts the efficiency and quality of subsequent DNA repair. Specifically eliminating E5 not only precludes CSR but also, causes an atypical, enzymatic activity-dependent dominant-negative effect on CSR. Moreover, the E5 domain is required for the formation of AID-dependent Igh-cMyc chromosomal translocations. DNA breaks at the Igh switch regions induced by AID lacking E5 display defective end joining, failing to recruit DNA damage response factors and undergoing extensive end resection. These defects lead to nonproductive resolutions, such as rearrangements and homologous recombination that can antagonize CSR. Our results can explain the autosomal dominant inheritance of AID variants with truncated E5 in patients with hyper-IgM syndrome 2 and establish that AID, through the E5 domain, provides a link between DNA damage and repair during CSR.
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Abstract
In this review, I discuss the currently available experimental evidence concerning the molecular interactions of the activation-induced cytidine deaminase (AID) with transcription of its target genes. The basic question that underlies the transcription relationship is how the process of somatic hypermutation of Ig genes can be restricted to their variable (V) regions. This hallmark of SHM assures that high affinity antibodies can be created while the biological functions of their constant (C) region are undisturbed. I present a revised model of AID function in somatic hypermutation (SHM): In a B cell that produces AID protein and undergoes mutation of the V regions of the expressed Ig heavy and light chain genes, only some of the transcription complexes initiating at the active V-region promoters are associated with AID. When AID travels with the elongating RNA polymerase (pol), it attracts proteins that cause the pausing/stalling of pol and termination of transcription, followed by termination of SHM. This differential AID loading model would allow the mutating B cell to continue producing full-length Ig proteins that are required to avoid apoptosis by permitting the cell to assemble functional B cell receptors.
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Affiliation(s)
- Ursula Storb
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, Illinois, USA.
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25
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Hwang IY, Park C, Luong T, Harrison KA, Birnbaumer L, Kehrl JH. The loss of Gnai2 and Gnai3 in B cells eliminates B lymphocyte compartments and leads to a hyper-IgM like syndrome. PLoS One 2013; 8:e72596. [PMID: 23977324 PMCID: PMC3747273 DOI: 10.1371/journal.pone.0072596] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 07/18/2013] [Indexed: 11/22/2022] Open
Abstract
B lymphocytes are compartmentalized within lymphoid organs. The organization of these compartments depends upon signaling initiated by G-protein linked chemoattractant receptors. To address the importance of the G-proteins Gαi2 and Gαi3 in chemoattractant signaling we created mice lacking both proteins in their B lymphocytes. While bone marrow B cell development and egress is grossly intact; mucosal sites, splenic marginal zones, and lymph nodes essentially lack B cells. There is a partial block in splenic follicular B cell development and a 50-60% reduction in splenic B cells, yet normal numbers of splenic T cells. The absence of Gαi2 and Gαi3 in B cells profoundly disturbs the architecture of lymphoid organs with loss of B cell compartments in the spleen, thymus, lymph nodes, and gastrointestinal tract. This results in a severe disruption of B cell function and a hyper-IgM like syndrome. Beyond the pro-B cell stage, B cells are refractory to chemokine stimulation, and splenic B cells are poorly responsive to antigen receptor engagement. Gαi2 and Gαi3 are therefore critical for B cell chemoattractant receptor signaling and for normal B cell function. These mice provide a worst case scenario of the consequences of losing chemoattractant receptor signaling in B cells.
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Affiliation(s)
- Il-Young Hwang
- B Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Chung Park
- B Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Thuyvi Luong
- B Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Kathleen A. Harrison
- B Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Lutz Birnbaumer
- Laboratory of Neurobiology, National Institute of Environmental Health Sciences, National Institutes of Health/Department of Health and Human Services, Durham, North Carolina, United States of America
| | - John H. Kehrl
- B Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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26
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Caratão N, Cortesão CS, Reis PH, Freitas RF, Jacob CM, Pastorino AC, Carneiro-Sampaio M, Barreto VM. A novel activation-induced cytidine deaminase (AID) mutation in Brazilian patients with hyper-IgM type 2 syndrome. Clin Immunol 2013; 148:279-86. [DOI: 10.1016/j.clim.2013.05.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 05/22/2013] [Accepted: 05/31/2013] [Indexed: 12/30/2022]
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27
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Salek Farrokhi A, Aghamohammadi A, Pourhamdi S, Mohammadinejad P, Abolhassani H, Moazzeni SM. Evaluation of class switch recombination in B lymphocytes of patients with common variable immunodeficiency. J Immunol Methods 2013; 394:94-9. [DOI: 10.1016/j.jim.2013.05.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 05/20/2013] [Accepted: 05/20/2013] [Indexed: 10/26/2022]
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Durandy A, Cantaert T, Kracker S, Meffre E. Potential roles of activation-induced cytidine deaminase in promotion or prevention of autoimmunity in humans. Autoimmunity 2013; 46:148-56. [PMID: 23215867 DOI: 10.3109/08916934.2012.750299] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Autoimmune manifestations are paradoxical and frequent complications of primary immunodeficiencies, including T and/or B cell defects. Among pure B cell defects, the Activation-induced cytidine Deaminase (AID)-deficiency, characterized by a complete lack of immunoglobulin class switch recombination and somatic hypermutation, is especially complicated by autoimmune disorders. We summarized in this review the different autoimmune and inflammatory manifestations present in 13 patients out of a cohort of 45 patients. Moreover, we also review the impact of AID mutations on B-cell tolerance and discuss hypotheses that may explain why central and peripheral B-cell tolerance was abnormal in the absence of functional AID. Hence, AID plays an essential role in controlling autoreactive B cells in humans and prevents the development of autoimmune syndromes.
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Affiliation(s)
- Anne Durandy
- INSERM, Unité U768, Hôpital Necker Enfants-Malades, Paris, France.
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29
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Schroeder HW, Szymanska-Mroczek E. Primary antibody deficiencies. Clin Immunol 2013. [DOI: 10.1016/b978-0-7234-3691-1.00051-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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30
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Jaszczur M, Bertram JG, Pham P, Scharff MD, Goodman MF. AID and Apobec3G haphazard deamination and mutational diversity. Cell Mol Life Sci 2012. [PMID: 23178850 DOI: 10.1007/s00018-012-1212-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Activation-induced deoxycytidine deaminase (AID) and Apobec 3G (Apo3G) cause mutational diversity by initiating mutations on regions of single-stranded (ss) DNA. Expressed in B cells, AID deaminates C → U in actively transcribed immunoglobulin (Ig) variable and switch regions to initiate the somatic hypermutation (SHM) and class switch recombination (CSR) that are essential for antibody diversity. Apo3G expressed in T cells catalyzes C deaminations on reverse transcribed cDNA causing HIV-1 retroviral inactivation. When operating properly, AID- and Apo3G-initiated mutations boost human fitness. Yet, both enzymes are potentially powerful somatic cell "mutators". Loss of regulated expression and proper genome targeting can cause human cancer. Here, we review well-established biological roles of AID and Apo3G. We provide a synopsis of AID partnering proteins during SHM and CSR, and describe how an Apo2 crystal structure provides "surrogate" insight for AID and Apo3G biochemical behavior. However, large gaps remain in our understanding of how dC deaminases search ssDNA to identify trinucleotide motifs to deaminate. We discuss two recent methods to analyze ssDNA scanning and deamination. Apo3G scanning and deamination is visualized in real-time using single-molecule FRET, and AID deamination efficiencies are determined with a random walk analysis. AID and Apo3G encounter many candidate deamination sites while scanning ssDNA. Generating mutational diversity is a principal aim of AID and an important ancillary property of Apo3G. Success seems likely to involve hit and miss deamination motif targeting, biased strongly toward miss.
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Affiliation(s)
- Malgorzata Jaszczur
- Departments of Biological Sciences and Chemistry, Molecular and Computational Biology Section, University of Southern California, Los Angeles, CA 90089-2910, USA
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Immunoglobulin gene repertoire in chronic lymphocytic leukemia: insight into antigen selection and microenvironmental interactions. Mediterr J Hematol Infect Dis 2012; 4:e2012052. [PMID: 22973496 PMCID: PMC3435129 DOI: 10.4084/mjhid.2012.052] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2012] [Accepted: 07/16/2012] [Indexed: 11/08/2022] Open
Abstract
Immunogenetic analysis of the B cell receptors (BCRs) has been a richly rewarding field for unraveling the pathogenesis of human lymphomas, including CLL. A biased immunoglobulin gene repertoire is seen as evidence for selection of CLL progenitor cells by antigen. Additional corroborative evidence is provided by the differential prognosis of cases with distinct mutational status of the clonotypic BCRs. However, perhaps the strongest immunogenetic evidence for the importance of interactions with microenvironment in driving CLL development and evolution is the existence of subsets of patients with quasi-identical, stereotyped BCRs, collectively accounting for a remarkable one-third of the entire cohort. These observations have been instrumental in shaping the notion that CLL ontogeny is functionally driven and dynamic, rather than a simple stochastic process. From a clinical perspective, ample evidence indicates that immunogenetic information can be used for the biologically and clinically rational categorization of CLL, with important potential implications for basic, translational and clinical research.
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32
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Abstract
Immunoglobulin class-switch recombination deficiencies (Ig-CSR-Ds) are rare primary immunodeficiencies characterized by defective switched isotype (IgG/IgA/IgE) production. Depending on the molecular defect in question, the Ig-CSR-D may be combined with an impairment in somatic hypermutation (SHM). Some of the mechanisms underlying Ig-CSR and SHM have been described by studying natural mutants in humans. This approach has revealed that T cell-B cell interaction (resulting in CD40-mediated signaling), intrinsic B-cell mechanisms (activation-induced cytidine deaminase-induced DNA damage), and complex DNA repair machineries (including uracil-N-glycosylase and mismatch repair pathways) are all involved in class-switch recombination and SHM. However, several of the mechanisms required for full antibody maturation have yet to be defined. Elucidation of the molecular defects underlying the diverse set of Ig-CSR-Ds is essential for understanding Ig diversification and has prompted better definition of the clinical spectrum of diseases and the development of increasingly accurate diagnostic and therapeutic approaches.
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Duarte-Rey C, Bogdanos DP, Leung PS, Anaya JM, Gershwin ME. IgM predominance in autoimmune disease: Genetics and gender. Autoimmun Rev 2012; 11:A404-12. [DOI: 10.1016/j.autrev.2011.12.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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de Miranda NF, Björkman A, Pan-Hammarström Q. DNA repair: the link between primary immunodeficiency and cancer. Ann N Y Acad Sci 2012; 1246:50-63. [PMID: 22236430 DOI: 10.1111/j.1749-6632.2011.06322.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The adaptive component of the immune system depends greatly on the generation of genetic diversity provided by lymphocyte-specific genomic rearrangements. V(D)J recombination, class switch recombination (CSR), and somatic hypermutation (SHM) constitute complex and vulnerable processes that are orchestrated by a multitude of DNA repair pathways. When inherited defects in certain DNA repair proteins are present, lymphocyte development can be compromised and, consequently, patients can develop primary immunodeficiencies (PIDs). PID patients often have a strong predisposition for cancer development as a result of genomic instability generated from defective DNA repair mechanisms. Tumors of lymphoid origin are one of the most common PID-associated cancers, likely due to DNA lesions resulting from defective V(D)J, CSR, and SHM. In this review, we describe PID syndromes that confer an increased risk for cancer development. Furthermore, we discuss the role of the affected proteins in tumorigenesis/lymphomagenesis.
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Affiliation(s)
- Noel Fcc de Miranda
- Division of Clinical Immunology, Department of Laboratory Medicine, Karolinska Institutet at Karolinska University Hospital Huddinge, Stockholm, Sweden
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Micol R, Kayal S, Mahlaoui N, Beauté J, Brosselin P, Dudoit Y, Obenga G, Barlogis V, Aladjidi N, Kebaili K, Thomas C, Dulieu F, Monpoux F, Nové-Josserand R, Pellier I, Lambotte O, Salmon A, Masseau A, Galanaud P, Oksenhendler E, Tabone MD, Teira P, Coignard-Biehler H, Lanternier F, Join-Lambert O, Mouillot G, Theodorou I, Lecron JC, Alyanakian MA, Picard C, Blanche S, Hermine O, Suarez F, Debré M, Lecuit M, Lortholary O, Durandy A, Fischer A. Protective effect of IgM against colonization of the respiratory tract by nontypeable Haemophilus influenzae in patients with hypogammaglobulinemia. J Allergy Clin Immunol 2011; 129:770-7. [PMID: 22153772 DOI: 10.1016/j.jaci.2011.09.047] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Revised: 09/01/2011] [Accepted: 09/26/2011] [Indexed: 11/29/2022]
Abstract
BACKGROUND Primary immunoglobulin deficiencies lead to recurrent bacterial infections of the respiratory tract and bronchiectasis, even with adequate immunoglobulin replacement therapy. It is not known whether patients able to secrete IgM (eg, those with hyper-IgM [HIgM] syndrome) are as susceptible to these infections as patients who lack IgM production (eg, those with panhypogammaglobulinemia [PHG]). OBJECTIVE This study is aimed at identifying specific microbiological and clinical (infections) characteristics that distinguish immunoglobulin-substituted patients with PHG from patients with HIgM syndrome. METHODS A cohort of patients with HIgM syndrome (n = 25) and a cohort of patients with PHG (n = 86) were monitored prospectively for 2 years while receiving similar polyvalent immunoglobulin replacement therapies. Regular bacterial analyses of nasal swabs and sputum were performed, and clinical events were recorded. In parallel, serum and saliva IgM antibody concentrations were measured. RESULTS When compared with patients with PHG, patients with HIgM syndrome were found to have a significantly lower risk of nontypeable Haemophilus influenzae carriage in particular (relative risk, 0.39; 95% CI, 0.21-0.63). Moreover, patients with HIgM syndrome (including those unable to generate somatic hypermutations of immunoglobulin genes) displayed anti-nontypeable H influenzae IgM antibodies in their serum and saliva. Also, patients with HIgM syndrome had a lower incidence of acute respiratory tract infections. CONCLUSIONS IgM antibodies appear to be microbiologically and clinically protective and might thus attenuate the infectious consequences of a lack of production of other immunoglobulin isotypes in patients with HIgM syndrome. Polyvalent IgG replacement therapy might not fully compensate for IgM deficiency. It might thus be worth adapting long-term antimicrobial prophylactic regimens according to the underlying B-cell immunodeficiency phenotype.
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Affiliation(s)
- Romain Micol
- CEREDIH Network (French National Reference Center for Primary Immunodeficiencies), Hôpital Necker-Enfants Malades, AP-HP, Paris, France
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Study of patients with Hyper-IgM type IV phenotype who recovered spontaneously during late childhood and review of the literature. Eur J Pediatr 2011; 170:1039-47. [PMID: 21274562 DOI: 10.1007/s00431-011-1400-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2010] [Accepted: 01/11/2011] [Indexed: 01/21/2023]
Abstract
UNLABELLED Hyper-IgM syndromes are characterized by normal or elevated serum IgM levels with the absence or reduced levels of other immunoglobulins. There are some patients with defective class-switch recombination (CSR) who do not have CD40L, CD40, AID, and UNG defects. The aim of this study is to determine the B-cell functions of patients with Hyper-IgM type 4 phenotype. Ten patients (seven males and three females) 84.2 ± 16.5 months of age with initial low serum IgG and IgA and high or normal IgM levels were included. Clinically, 50% had recurrent upper respiratory tract, 10% urinary tract, 10% lower respiratory tract infections, and 30% had mixed type infections. Lymphoid hyperplasia, overt autoimmune manifestations, or malignancy was not noted. Seven of 10 patients were studied twice; at the age of 34.2 ± 13.7 and at 86.6 ± 12.3 months. Absolute lymphocyte counts and lymphocyte subsets were normal in all cases. All of them had normal expression of CD40 on B cells and CD40L on activated T cells for males. At first examination, all patients had normal in vitro sCD40L+rIL-4-induced B cell proliferation response and somatic hypermutation but CSR towards IgE was absent. AID and UNG genes did not show any abnormalities. All showed improvement in both clinical findings and Ig levels during the follow-up period of 55.8 ± 14.8 months. Ages for normalization of IgG and IgA were 68.2 ± 8.7 and 70.2 ± 21.6 months, respectively. During the second evaluation: In vitro sCD40L+rIL-4-induced B-cell proliferation was normal in all cases, whereas CSR was still abnormal in five of eight patients. Two of the patients had an increase in in vitro CSR response but still low IgG2 subclass levels. Three patients with initially absent in vitro CSR response also normalized. CONCLUSION Clinical manifestations and immunoglobulin levels of the patients with Hyper-IgM type 4 phenotype recovered in late childhood at about 6 years of age. There was a transient CSR defect which was not observed in cases with transient hypogammaglobulinemia of infancy. Detection of a non-AID or non-UNG associated CSR defect in infancy should be confirmed later on since spontaneous recovery may occur.
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Distribution, clinical features and treatment in Taiwanese patients with symptomatic primary immunodeficiency diseases (PIDs) in a nationwide population-based study during 1985-2010. Immunobiology 2011; 216:1286-94. [PMID: 21782277 DOI: 10.1016/j.imbio.2011.06.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2011] [Revised: 05/29/2011] [Accepted: 06/13/2011] [Indexed: 01/14/2023]
Abstract
Primary immunodeficiency diseases (PIDs) are a group of rare diseases with wide geographic and ethnic variations in incidence, prevalence, and distribution patterns. The aim of this study was to examine the distribution pattern and clinical spectrum of PIDs in Taiwan at a national referral institute. From 1985 to 2010, 215 patients from 183 families were diagnosed and grouped according to the updated classification of PIDs. Eighty-one (37.7%) patients had "other well-defined immunodeficiency syndromes", followed by "predominantly antibody deficiencies" (54 patients; 25.1%), "T- and B-cell immunodeficiencies" (34; 15.8%), "congenital defects of phagocytes" (25; 20.2%), "complement deficiencies" (15; 7.0%), and "disease in immune dysregulation" (5; 2.3%). The last category included two patients with Chediak-Higashi syndrome, and one each with familial hemophagocytosis, IPEX, and hypogammaglobulinemia and albinism. One female had cold-induced auto-inflammatory disease. There were no cases of "defects in innate immunity". Pseudomonas and Streptococcus pneumoniae were the two most identified microorganisms in septicemia (42.7%; 44/103 episodes). Stem cell transplantation was successful in 13 of 22 patients, while 34 patients (15.8%) died. Molecular defects were identified in 109 individuals (from 90 families). There were relatively fewer cases of "predominantly antibody deficiencies" due to there being only a few patients with adult-onset PIDs, implying certainty bias rather than ethnic variation. Awareness of under-diagnosis among physicians rather than pediatricians is vital for timely diagnosis and consequently adequate treatment.
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38
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TNFRSF13B/TACI Alterations in Greek Patients with Antibody Deficiencies. J Clin Immunol 2011; 31:550-9. [DOI: 10.1007/s10875-011-9536-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 04/12/2011] [Indexed: 10/18/2022]
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Wilson DM, Kim D, Berquist BR, Sigurdson AJ. Variation in base excision repair capacity. Mutat Res 2010; 711:100-12. [PMID: 21167187 DOI: 10.1016/j.mrfmmm.2010.12.004] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Revised: 11/29/2010] [Accepted: 12/07/2010] [Indexed: 01/20/2023]
Abstract
The major DNA repair pathway for coping with spontaneous forms of DNA damage, such as natural hydrolytic products or oxidative lesions, is base excision repair (BER). In particular, BER processes mutagenic and cytotoxic DNA lesions such as non-bulky base modifications, abasic sites, and a range of chemically distinct single-strand breaks. Defects in BER have been linked to cancer predisposition, neurodegenerative disorders, and immunodeficiency. Recent data indicate a large degree of sequence variability in DNA repair genes and several studies have associated BER gene polymorphisms with disease risk, including cancer of several sites. The intent of this review is to describe the range of BER capacity among individuals and the functional consequences of BER genetic variants. We also discuss studies that associate BER deficiency with disease risk and the current state of BER capacity measurement assays.
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Affiliation(s)
- David M Wilson
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, United States.
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40
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Hasham MG, Donghia NM, Coffey E, Maynard J, Snow KJ, Ames J, Wilpan RY, He Y, King BL, Mills KD. Widespread genomic breaks generated by activation-induced cytidine deaminase are prevented by homologous recombination. Nat Immunol 2010; 11:820-6. [PMID: 20657597 PMCID: PMC2930818 DOI: 10.1038/ni.1909] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2010] [Accepted: 06/22/2010] [Indexed: 01/21/2023]
Abstract
Activation induced cytidine deaminase (AID) is required for somatic hypermutation and immunoglobulin class switching in activated B cells. Because AID possesses no known target site specificity, there have been efforts to identify non-immunoglobulin AID targets. We show that AID acts promiscuously, generating widespread DNA double strand breaks (DSB), genomic instability and cytotoxicity in B cells with diminished homologous recombination (HR) capability. We demonstrate that the HR factor XRCC2 suppresses AID-induced off-target DSBs, promoting B cell survival. Finally, we suggest that aberrations affecting human chromosome 7q36, including XRCC2, correlate with genomic instability in B cell cancers. Our findings demonstrate that AID has promiscuous genomic DSB-inducing activity, identify HR as a safeguard against off-target AID action, and have implications for genomic instability in B cell cancers.
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41
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Fagarasan S, Kawamoto S, Kanagawa O, Suzuki K. Adaptive immune regulation in the gut: T cell-dependent and T cell-independent IgA synthesis. Annu Rev Immunol 2010; 28:243-73. [PMID: 20192805 DOI: 10.1146/annurev-immunol-030409-101314] [Citation(s) in RCA: 350] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In mammals, the gastrointestinal tract harbors an extraordinarily dense and complex community of microorganisms. The gut microbiota provide strong selective pressure to the host to evolve adaptive immune responses required for the maintenance of local and systemic homeostasis. The continuous antigenic presence in the gut imposes a dynamic remodeling of gut-associated lymphoid tissues (GALT) and the selection of multiple layered strategies for immunoglobulin (Ig) A production. The composite and dynamic gut environment also necessitates heterogeneous, versatile, and convertible T cells, capable of inhibiting (Foxp3(+) T cells) or helping (T(FH) cells) local immune responses. In this review, we describe recent advances in our understanding of dynamic pathways that lead to IgA synthesis, in gut follicular structures and in extrafollicular sites, by T cell-dependent and T cell-independent mechanisms. We discuss the finely tuned regulatory mechanisms for IgA production and emphasize the role of mucosal IgA in the selection and maintenance of the appropriate microbial composition that is necessary for immune homeostasis.
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42
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Kracker S, Gardes P, Mazerolles F, Durandy A. Immunoglobulin class switch recombination deficiencies. Clin Immunol 2010; 135:193-203. [DOI: 10.1016/j.clim.2010.01.012] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2009] [Revised: 01/25/2010] [Accepted: 01/25/2010] [Indexed: 01/01/2023]
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43
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Li L, Halaby MJ, Hakem A, Cardoso R, El Ghamrasni S, Harding S, Chan N, Bristow R, Sanchez O, Durocher D, Hakem R. Rnf8 deficiency impairs class switch recombination, spermatogenesis, and genomic integrity and predisposes for cancer. ACTA ACUST UNITED AC 2010; 207:983-97. [PMID: 20385750 PMCID: PMC2867283 DOI: 10.1084/jem.20092437] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Signaling and repair of DNA double-strand breaks (DSBs) are critical for preventing immunodeficiency and cancer. These DNA breaks result from exogenous and endogenous DNA insults but are also programmed to occur during physiological processes such as meiosis and immunoglobulin heavy chain (IgH) class switch recombination (CSR). Recent studies reported that the E3 ligase RNF8 plays important roles in propagating DNA DSB signals and thereby facilitating the recruitment of various DNA damage response proteins, such as 53BP1 and BRCA1, to sites of damage. Using mouse models for Rnf8 mutation, we report that Rnf8 deficiency leads to impaired spermatogenesis and increased sensitivity to ionizing radiation both in vitro and in vivo. We also demonstrate the existence of alternative Rnf8-independent mechanisms that respond to irradiation and accounts for the partial recruitment of 53bp1 to sites of DNA damage in activated Rnf8(-/-) B cells. Remarkably, IgH CSR is impaired in a gene dose-dependent manner in Rnf8 mutant mice, revealing that these mice are immunodeficient. In addition, Rnf8(-/-) mice exhibit increased genomic instability and elevated risks for tumorigenesis indicating that Rnf8 is a novel tumor suppressor. These data unravel the in vivo pleiotropic effects of Rnf8.
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Affiliation(s)
- Li Li
- Department of Medical Biophysics, University of Toronto and Ontario Cancer Institute, University Health Network, Toronto, Ontario M5G 2M9, Canada
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44
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Chaplin DD. Overview of the immune response. J Allergy Clin Immunol 2010; 125:S3-23. [PMID: 20176265 DOI: 10.1016/j.jaci.2009.12.980] [Citation(s) in RCA: 978] [Impact Index Per Article: 69.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2009] [Revised: 12/18/2009] [Accepted: 12/21/2009] [Indexed: 12/12/2022]
Abstract
The immune system has evolved to protect the host from a universe of pathogenic microbes that are themselves constantly evolving. The immune system also helps the host eliminate toxic or allergenic substances that enter through mucosal surfaces. Central to the immune system's ability to mobilize a response to an invading pathogen, toxin, or allergen is its ability to distinguish self from nonself. The host uses both innate and adaptive mechanisms to detect and eliminate pathogenic microbes, and both of these mechanisms include self-nonself discrimination. This overview identifies key mechanisms used by the immune system to respond to invading microbes and other exogenous threats and identifies settings in which disturbed immune function exacerbates tissue injury.
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Affiliation(s)
- David D Chaplin
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294-2170, USA.
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45
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Hennig C, Baumann U, Ilginus C, Horneff G, Foell J, Hansen G. Successful treatment of autoimmune and lymphoproliferative complications of patients with intrinsic B-cell immunodeficiencies with Rituximab. Br J Haematol 2010; 148:445-8. [DOI: 10.1111/j.1365-2141.2009.07987.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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46
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van Maldegem F, Jibodh RA, van Dijk R, Bende RJ, van Noesel CJM. Activation-induced cytidine deaminase splice variants are defective because of the lack of structural support for the catalytic site. THE JOURNAL OF IMMUNOLOGY 2010; 184:2487-91. [PMID: 20118283 DOI: 10.4049/jimmunol.0903102] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Recently, conflicting results were reported on the hypermutation activity of activation-induced cytidine deaminase (AID) splice variants. With the generation of single point mutations, we studied the structure-function relationship of the amino acids that are commonly absent from all described splice variants. The results from this analysis pointed to several amino acids that are required for class switch recombination (CSR), without perturbing cellular localization or nucleocytoplasmic shuttling. A defect in deaminase activity was found to underlie this CSR deficiency. Interestingly, the most debilitating mutations concentrated on hydrophobic amino acids, suggesting a structural role for this part of the protein. Indeed, by generating homologous amino acid replacements, CSR activity could be restored. These results are in agreement with recent reports on the protein structure of the AID homolog APOBEC3G, suggesting a similar protein composition. In addition, the findings underscore that AID splice variants are unlikely to have preservation of catalytic activity.
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Affiliation(s)
- Febe van Maldegem
- Department of Pathology, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
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47
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Basso K, Dalla-Favera R. BCL6: master regulator of the germinal center reaction and key oncogene in B cell lymphomagenesis. Adv Immunol 2010; 105:193-210. [PMID: 20510734 DOI: 10.1016/s0065-2776(10)05007-8] [Citation(s) in RCA: 224] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BCL6 is a transcriptional repressor which has emerged as a critical regulator of germinal centers (GC), the sites where B cells are selected based on the production of antibodies with high affinity for the antigen. BCL6 is also a frequently activated oncogene in the pathogenesis of human B cell lymphomas, most of which derive from the GC B cells. A thorough understanding of the biological role of BCL6 in normal B cell development and lymphomagenesis depends upon the identification of the full set of genes that are targets of its transcriptional regulatory function. Recently, the identification of BCL6 targets has been implemented with the use of genome-wide chromatin immunoprecipitation and gene expression profiling approaches. A large set of promoters have been shown to be physically bound by BCL6, but only a fraction of them appears to be subjected to transcriptional repression in GC B cells. This set of BCL6 targets points to a number of cellular functions which are likely to be directly controlled by BCL6 during GC development, including activation, survival, DNA-damage response, cell cycle arrest, cytokine-, toll-like receptor-, TGFbeta-, WNT-signaling, and differentiation. Overall, BCL6 is revealing its dual role of "safe-keeper" in preventing centroblasts from responding to signals leading to a premature exit from the GC and of contributor to lymphomagenesis by allowing the instauration of conditions favorable to malignant transformation.
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Affiliation(s)
- Katia Basso
- Institute for Cancer Genetics, Columbia University, New York, NY, USA
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48
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Pone EJ, Zan H, Zhang J, Al-Qahtani A, Xu Z, Casali P. Toll-like receptors and B-cell receptors synergize to induce immunoglobulin class-switch DNA recombination: relevance to microbial antibody responses. Crit Rev Immunol 2010; 30:1-29. [PMID: 20370617 PMCID: PMC3038989 DOI: 10.1615/critrevimmunol.v30.i1.10] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Differentiation of naïve B cells, including immunoglobulin class-switch DNA recombination, is critical for the immune response and depends on the extensive integration of signals from the B-cell receptor (BCR), tumor necrosis factor (TNF) family members, Toll-like receptors (TLRs), and cytokine receptors. TLRs and BCR synergize to induce class-switch DNA recombination in T cell-dependent and T cell-independent antibody responses to microbial pathogens. BCR triggering together with simultaneous endosomal TLR engagement leads to enhanced B-cell differentiation and antibody responses. Te requirement of both BCR and TLR engagement would ensure appropriate antigen-specific activation in an infection. Co-stimulation of TLRs and BCR likely plays a significant role in anti-microbial antibody responses to contain pathogen loads until the T cell-dependent antibody responses peak. Furthermore, the temporal sequence of different signals is also critical for optimal B cell responses, as exemplified by the activation of B cells by initial TLR engagement, leading to the up-regulation of co-stimulatory CD80 and MCH-II receptors, which result in more efficient interactions with T cells, thereby enhancing the germinal center reaction and antibody affinity maturation. Overall, BCR and TLR stimulation and the integration with signals from the pathogen or immune cells and their products determine the ensuing B-cell antibody response.
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Affiliation(s)
- Egest J. Pone
- Institute for Immunology, School of Medicine and School of Biological Sciences, University of California, Irvine, CA 92697-4120, USA
| | - Hong Zan
- Institute for Immunology, School of Medicine and School of Biological Sciences, University of California, Irvine, CA 92697-4120, USA
| | - Jinsong Zhang
- Institute for Immunology, School of Medicine and School of Biological Sciences, University of California, Irvine, CA 92697-4120, USA
| | - Ahmed Al-Qahtani
- Institute for Immunology, School of Medicine and School of Biological Sciences, University of California, Irvine, CA 92697-4120, USA
| | - Zhenming Xu
- Institute for Immunology, School of Medicine and School of Biological Sciences, University of California, Irvine, CA 92697-4120, USA
| | - Paolo Casali
- Institute for Immunology, School of Medicine and School of Biological Sciences, University of California, Irvine, CA 92697-4120, USA
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49
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Primary immunodeficiencies. J Allergy Clin Immunol 2009; 125:S182-94. [PMID: 20042228 DOI: 10.1016/j.jaci.2009.07.053] [Citation(s) in RCA: 298] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2009] [Revised: 07/27/2009] [Accepted: 07/30/2009] [Indexed: 12/14/2022]
Abstract
In the last years, advances in molecular genetics and immunology have resulted in the identification of a growing number of genes causing primary immunodeficiencies (PIDs) in human subjects and a better understanding of the pathophysiology of these disorders. Characterization of the molecular mechanisms of PIDs has also facilitated the development of novel diagnostic assays based on analysis of the expression of the protein encoded by the PID-specific gene. Pilot newborn screening programs for the identification of infants with severe combined immunodeficiency have been initiated. Finally, significant advances have been made in the treatment of PIDs based on the use of subcutaneous immunoglobulins, hematopoietic cell transplantation from unrelated donors and cord blood, and gene therapy. In this review we will discuss the pathogenesis, diagnosis, and treatment of PIDs, with special attention to recent advances in the field.
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50
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Conley ME. Genetics of hypogammaglobulinemia: what do we really know? Curr Opin Immunol 2009; 21:466-71. [PMID: 19651503 DOI: 10.1016/j.coi.2009.07.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2009] [Revised: 07/03/2009] [Accepted: 07/03/2009] [Indexed: 11/19/2022]
Abstract
In the past, immunodeficiencies were categorized based on clinical and laboratory findings in the affected patient. Now we are more likely to define them based on the specific gene involved. One might expect this shift to increase the precision and clarity of diagnosis but in the last few years it has become increasingly clear that identification of a mutation in a specific gene may not tell the whole story. Some gene defects may reliably result in clinical disease, others may act as susceptibility factors that are more common in patients with immunodeficiency but can also be found in otherwise healthy individuals. Distinguishing between these two types of gene defects is essential for informative genetic counseling.
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Affiliation(s)
- Mary Ellen Conley
- Department of Pediatrics, University of Tennessee College of Medicine, Memphis, TN, USA.
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