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Weniger MA, Seifert M, Küppers R. B Cell Differentiation and the Origin and Pathogenesis of Human B Cell Lymphomas. Methods Mol Biol 2025; 2865:1-30. [PMID: 39424718 DOI: 10.1007/978-1-0716-4188-0_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2024]
Abstract
Immunoglobulin (IG) gene remodeling by V(D)J recombination plays a central role in the generation of normal B cells, and somatic hypermutation and class switching of IG genes are key processes during antigen-driven B cell differentiation in the germinal center reaction. However, errors of these processes are involved in the development of B cell lymphomas. IG locus-associated translocations of proto-oncogenes are a hallmark of many B cell malignancies. Additional transforming events include inactivating mutations in various tumor suppressor genes and also latent infection of B cells with viruses, such as Epstein-Barr virus. Most B cell lymphomas require B cell antigen receptor expression, and in several instances chronic antigenic stimulation plays a role in lymphoma development and/or sustaining tumor growth. Often, survival and proliferation signals provided by other cells in the microenvironment are a further critical factor in lymphoma development and pathophysiology. Most B cell malignancies derive from germinal center B cells, most likely due to the high proliferative activity of these B cells and aberrant mutations caused by their naturally active mutagenic processes.
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Affiliation(s)
- Marc A Weniger
- Institute of Cell Biology (Cancer Research), University of Duisburg-Essen, Medical School, Essen, Germany
| | - Marc Seifert
- Department of Haematology, Oncology and Clinical Immunology, Heinrich Heine University, Medical School, Düsseldorf, Germany
| | - Ralf Küppers
- Institute of Cell Biology (Cancer Research), University of Duisburg-Essen, Medical School, Essen, Germany.
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2
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Yang H, Sun C, Ye L, Xu Y, Lin S, Peng Q, Wang G, Lu X. Association of anti-HMGCR antibodies of the IgM isotype with refractory immune-mediated necrotizing myopathy. Arthritis Res Ther 2024; 26:158. [PMID: 39261921 PMCID: PMC11389351 DOI: 10.1186/s13075-024-03387-6] [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: 07/01/2024] [Accepted: 08/25/2024] [Indexed: 09/13/2024] Open
Abstract
OBJECTIVE Anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) autoantibodies are one of the myositis-specific antibodies which is associated with immune-mediated necrotizing myopathy (IMNM). However, the relationship between anti-HMGCR isotypes and prognosis has not yet been fully investigated. This study was conducted to gain insight into the association between anti-HMGCR isotypes and clinical, and prognosis in IMNM patients who were positive for anti-HMGCR antibodies. METHODS Levels of anti-HMGCR isotypes (IgG, IgA and IgM) were assessed by enzyme-linked immunosorbent assay (ELISA) in 123 consecutive serum samples obtained from 71 patients who were positive for anti-HMGCR IgG at baseline. Disease activity was assessed by manual muscle testing (MMT) 8, Physician's Global Assessment (PGA) visual analog scale (VAS), and muscle VAS. RESULTS Baseline anti-HMGCR IgG levels were correlated with PGA VAS (r = 0.24; p = 0.04), muscle VAS (r = 0.32; p < 0.01), and MMT8(r=-0.24; p = 0.04), and baseline anti-HMGCR IgM levels were positively correlated with PGA VAS (r = 0.27, p = 0.02), muscle VAS (r = 0.24, p = 0.04). Anti-HMGCR IgM positive patients had a lower age of onset [29(25,46) vs. 51(33,65), p = 0.006], and a higher proportion of neck weakness (63.5% vs. 34.6%, p = 0.031) compared with anti-HMGCR IgM negative patients. Longitudinal analysis showed that the changes in anti-HMGCR IgG levels were correlated with the changes in the PGA VAS (β = 3.830; p < 0.0001), muscle VAS (β = 2.893; p < 0.0001), MMT8 (β=-19.368; p < 0.0001), and creatine kinase (CK) levels (β = 3900.05, p < 0.0001). Anti-HMGCR IgM levels were weakly correlated with anti-HMGCR IgA levels at baseline (r = 0.33, p < 0.01), and the variations in anti-HMGCR IgA levels were correlated with the changes in anti-HMGCR IgM levels during follow-up (β = 0.885; p < 0.0001). There were more patients with anti-HMGCR IgM who showed a refractory course than those who were with anti-HMGCR IgM negative (polycyclic course: 40% vs. 25%; chronic continuous course: 46.7% vs. 20.5%, p = 0.018). CONCLUSION In anti-HMGCR IgG-positive IMNM patients, the levels of anti-HMGCR IgG are associated with disease activity, and anti-HMGCR IgM is associated with refractory outcome and poor prognosis.
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Affiliation(s)
- Hongxia Yang
- Department of Rheumatology, Key Lab of Myositis, China-Japan Friendship Hospital, 2 Yinghua Road, Chaoyang District, Beijing, China
- Department of Clinical Laboratory, Peking University First Hospital, Beijing, China
| | - Chao Sun
- Department of Rheumatology, Key Lab of Myositis, China-Japan Friendship Hospital, 2 Yinghua Road, Chaoyang District, Beijing, China
| | - Lifang Ye
- Department of Rheumatology, Key Lab of Myositis, China-Japan Friendship Hospital, 2 Yinghua Road, Chaoyang District, Beijing, China
| | - Yuetong Xu
- Department of Rheumatology, Key Lab of Myositis, China-Japan Friendship Hospital, 2 Yinghua Road, Chaoyang District, Beijing, China
| | - Sang Lin
- Department of Rheumatology, Key Lab of Myositis, China-Japan Friendship Hospital, 2 Yinghua Road, Chaoyang District, Beijing, China
| | - Qinglin Peng
- Department of Rheumatology, Key Lab of Myositis, China-Japan Friendship Hospital, 2 Yinghua Road, Chaoyang District, Beijing, China
| | - Guochun Wang
- Department of Rheumatology, Key Lab of Myositis, China-Japan Friendship Hospital, 2 Yinghua Road, Chaoyang District, Beijing, China
| | - Xin Lu
- Department of Rheumatology, Key Lab of Myositis, China-Japan Friendship Hospital, 2 Yinghua Road, Chaoyang District, Beijing, China.
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Wang K, Cai L, Wang H, Shan S, Hu X, Zhang J. Protocol for fast clonal family inference and analysis from large-scale B cell receptor repertoire sequencing data. STAR Protoc 2024; 5:102969. [PMID: 38502687 PMCID: PMC10963638 DOI: 10.1016/j.xpro.2024.102969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 01/26/2024] [Accepted: 03/03/2024] [Indexed: 03/21/2024] Open
Abstract
The expeditious identification and comprehensive analysis of clonal families from extensive B cell receptor (BCR) repertoire sequencing data are imperative for elucidating the intricacies of B cell immune responses. Here, we introduce a computational pipeline designed to swiftly deduce clonal families from bulk BCR heavy-chain sequencing data, accompanied by a suite of functional modules tailored to streamline post-clustering analysis. The outlined methodology encompasses guidelines for software installation, meticulous data preparation, and the systematic inference and analysis of clonal families. For complete details on the use and execution of this protocol, please refer to Wang et al.1.
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Affiliation(s)
- Kaixuan Wang
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Linru Cai
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Hao Wang
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China; Georgia Tech Shenzhen Institute (GTSI), Tianjin University, Shenzhen, Guangdong, China
| | - Shiwen Shan
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Xihao Hu
- GV20 Therapeutics, Cambridge, MA, USA
| | - Jian Zhang
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China.
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4
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Roy K, Chakraborty M, Kumar A, Manna AK, Roy NS. The NFκB signaling system in the generation of B-cell subsets: from germinal center B cells to memory B cells and plasma cells. Front Immunol 2023; 14:1185597. [PMID: 38169968 PMCID: PMC10758606 DOI: 10.3389/fimmu.2023.1185597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 11/09/2023] [Indexed: 01/05/2024] Open
Abstract
Memory B cells and antibody-secreting cells are the two prime effector B cell populations that drive infection- and vaccine-induced long-term antibody-mediated immunity. The antibody-mediated immunity mostly relies on the formation of specialized structures within secondary lymphoid organs, called germinal centers (GCs), that facilitate the interactions between B cells, T cells, and antigen-presenting cells. Antigen-activated B cells may proliferate and differentiate into GC-independent plasmablasts and memory B cells or differentiate into GC B cells. The GC B cells undergo proliferation coupled to somatic hypermutation of their immunoglobulin genes for antibody affinity maturation. Subsequently, affinity mature GC B cells differentiate into GC-dependent plasma cells and memory B cells. Here, we review how the NFκB signaling system controls B cell proliferation and the generation of GC B cells, plasmablasts/plasma cells, and memory B cells. We also identify and discuss some important unanswered questions in this connection.
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Affiliation(s)
- Koushik Roy
- Division of Microbiology and Immunology, Department of Pathology, School of Medicine, University of Utah, Salt Lake City, UT, United States
| | - Mainak Chakraborty
- Division of Immunology, Indian Council of Medical Research-National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Ashok Kumar
- Division of Microbiology and Immunology, Department of Pathology, School of Medicine, University of Utah, Salt Lake City, UT, United States
| | - Asit Kumar Manna
- Division of Microbiology and Immunology, Department of Pathology, School of Medicine, University of Utah, Salt Lake City, UT, United States
- Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT, United States
| | - Neeladri Sekhar Roy
- Department of Biochemistry, School of Medicine, Emory University, Atlanta, GA, United States
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5
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Wang K, Hu X, Zhang J. Fast clonal family inference from large-scale B cell repertoire sequencing data. CELL REPORTS METHODS 2023; 3:100601. [PMID: 37788671 PMCID: PMC10626204 DOI: 10.1016/j.crmeth.2023.100601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 07/31/2023] [Accepted: 09/08/2023] [Indexed: 10/05/2023]
Abstract
Advances in high-throughput sequencing technologies have facilitated the large-scale characterization of B cell receptor (BCR) repertoires. However, the vast amount and high diversity of the BCR sequences pose challenges for efficient and biologically meaningful analysis. Here, we introduce fastBCR, an efficient computational approach for inferring B cell clonal families from massive BCR heavy chain sequences. We demonstrate that fastBCR substantially reduces the running time while ensuring high accuracy on simulated datasets with diverse numbers of B cell lineages and varying mutation rates. We apply fastBCR to real BCR sequencing data from peripheral blood samples of COVID-19 patients, showing that the inferred clonal families display disease-associated features, as well as corresponding antigen-binding specificity and affinity. Overall, our results demonstrate the advantages of fastBCR for analyzing BCR repertoire data, which will facilitate the identification of disease-associated antibodies and improve our understanding of the B cell immune response.
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Affiliation(s)
- Kaixuan Wang
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Xihao Hu
- GV20 Therapeutics, Cambridge, MA, USA
| | - Jian Zhang
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China.
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6
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Wang J, Muste Sadurni M, Saponaro M. RNAPII response to transcription-blocking DNA lesions in mammalian cells. FEBS J 2023; 290:4382-4394. [PMID: 35731652 PMCID: PMC10952651 DOI: 10.1111/febs.16561] [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: 11/12/2021] [Revised: 05/15/2022] [Accepted: 06/21/2022] [Indexed: 09/21/2023]
Abstract
RNA polymerase II moves along genes to decode genetic information stored in the mammalian genome into messenger RNA and different forms of non-coding RNA. However, the transcription process is frequently challenged by DNA lesions caused by exogenous and endogenous insults, among which helix-distorting DNA lesions and double-stranded DNA breaks are particularly harmful for cell survival. In response to such DNA damage, RNA polymerase II transcription is regulated both locally and globally by multi-layer mechanisms, whereas transcription-blocking lesions are repaired before transcription can recover. Failure in DNA damage repair will cause genome instability and cell death. Although recent studies have expanded our understanding of RNA polymerase II regulation confronting DNA lesions, it is still not always clear what the direct contribution of RNA polymerase II is in the DNA damage repair processes. In this review, we focus on how RNA polymerase II and transcription are both repressed by transcription stalling lesions such as DNA-adducts and double strand breaks, as well as how they are actively regulated to support the cellular response to DNA damage and favour the repair of lesions.
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Affiliation(s)
- Jianming Wang
- Transcription Associated Genome Instability Laboratory, Institute of Cancer and Genomic SciencesUniversity of BirminghamUK
| | - Martina Muste Sadurni
- Transcription Associated Genome Instability Laboratory, Institute of Cancer and Genomic SciencesUniversity of BirminghamUK
| | - Marco Saponaro
- Transcription Associated Genome Instability Laboratory, Institute of Cancer and Genomic SciencesUniversity of BirminghamUK
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Huang J, Wu C, Kloeber JA, Gao H, Gao M, Zhu Q, Chang Y, Zhao F, Guo G, Luo K, Dai H, Liu S, Huang Q, Kim W, Zhou Q, Zhu S, Wu Z, Tu X, Yin P, Deng M, Wang L, Yuan J, Lou Z. SLFN5-mediated chromatin dynamics sculpt higher-order DNA repair topology. Mol Cell 2023; 83:1043-1060.e10. [PMID: 36854302 PMCID: PMC10467573 DOI: 10.1016/j.molcel.2023.02.004] [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: 05/17/2022] [Revised: 12/23/2022] [Accepted: 02/01/2023] [Indexed: 03/02/2023]
Abstract
Repair of DNA double-strand breaks (DSBs) elicits three-dimensional (3D) chromatin topological changes. A recent finding reveals that 53BP1 assembles into a 3D chromatin topology pattern around DSBs. How this formation of a higher-order structure is configured and regulated remains enigmatic. Here, we report that SLFN5 is a critical factor for 53BP1 topological arrangement at DSBs. Using super-resolution imaging, we find that SLFN5 binds to 53BP1 chromatin domains to assemble a higher-order microdomain architecture by driving damaged chromatin dynamics at both DSBs and deprotected telomeres. Mechanistically, we propose that 53BP1 topology is shaped by two processes: (1) chromatin mobility driven by the SLFN5-LINC-microtubule axis and (2) the assembly of 53BP1 oligomers mediated by SLFN5. In mammals, SLFN5 deficiency disrupts the DSB repair topology and impairs non-homologous end joining, telomere fusions, class switch recombination, and sensitivity to poly (ADP-ribose) polymerase inhibitor. We establish a molecular mechanism that shapes higher-order chromatin topologies to safeguard genomic stability.
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Affiliation(s)
- Jinzhou Huang
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Chenming Wu
- Key Laboratory of Arrhythmias of the Ministry of Education of China, Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China
| | - Jake A Kloeber
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA; Medical Scientist Training Program, Mayo Clinic, Rochester, MN 55905, USA
| | - Huanyao Gao
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN 55905, USA
| | - Ming Gao
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Qian Zhu
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Yiming Chang
- Jinzhou Medical University, Shanghai East Hospital, Shanghai 200120, China
| | - Fei Zhao
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Guijie Guo
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Kuntian Luo
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Haiming Dai
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Sijia Liu
- Department of Artificial Intelligence and Informatics, Mayo Clinic, Rochester, MN 55905, USA
| | - Qiru Huang
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Wootae Kim
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Qin Zhou
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Shouhai Zhu
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Zheming Wu
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Xinyi Tu
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Ping Yin
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Min Deng
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Liewei Wang
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN 55905, USA
| | - Jian Yuan
- Key Laboratory of Arrhythmias of the Ministry of Education of China, Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China; Department of Biochemistry and Molecular Biology, Tongji University School of Medicine, Shanghai 200092, China.
| | - Zhenkun Lou
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA.
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Sible E, Attaway M, Fiorica G, Michel G, Chaudhuri J, Vuong BQ. Ataxia Telangiectasia Mutated and MSH2 Control Blunt DNA End Joining in Ig Class Switch Recombination. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2023; 210:369-376. [PMID: 36603026 PMCID: PMC9915862 DOI: 10.4049/jimmunol.2200590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 12/09/2022] [Indexed: 01/06/2023]
Abstract
Class-switch recombination (CSR) produces secondary Ig isotypes and requires activation-induced cytidine deaminase (AID)-dependent DNA deamination of intronic switch regions within the IgH (Igh) gene locus. Noncanonical repair of deaminated DNA by mismatch repair (MMR) or base excision repair (BER) creates DNA breaks that permit recombination between distal switch regions. Ataxia telangiectasia mutated (ATM)-dependent phosphorylation of AID at serine 38 (pS38-AID) promotes its interaction with apurinic/apyrimidinic endonuclease 1 (APE1), a BER protein, suggesting that ATM regulates CSR through BER. However, pS38-AID may also function in MMR during CSR, although the mechanism remains unknown. To examine whether ATM modulates BER- and/or MMR-dependent CSR, Atm-/- mice were bred to mice deficient for the MMR gene mutS homolog 2 (Msh2). Surprisingly, the predicted Mendelian frequencies of Atm-/-Msh2-/- adult mice were not obtained. To generate ATM and MSH2-deficient B cells, Atm was conditionally deleted on an Msh2-/- background using a floxed ATM allele (Atmf) and B cell-specific Cre recombinase expression (CD23-cre) to produce a deleted ATM allele (AtmD). As compared with AtmD/D and Msh2-/- mice and B cells, AtmD/DMsh2-/- mice and B cells display a reduced CSR phenotype. Interestingly, Sμ-Sγ1 junctions from AtmD/DMsh2-/- B cells that were induced to switch to IgG1 in vitro showed a significant loss of blunt end joins and an increase in insertions as compared with wild-type, AtmD/D, or Msh2-/- B cells. These data indicate that the absence of both ATM and MSH2 blocks nonhomologous end joining, leading to inefficient CSR. We propose a model whereby ATM and MSH2 function cooperatively to regulate end joining during CSR through pS38-AID.
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Affiliation(s)
- Emily Sible
- Biology PhD Program, The Graduate Center, The City University of New York, New York, NY
- Department of Biology, City College of New York, The City University of New York, New York, NY; and
| | - Mary Attaway
- Department of Biology, City College of New York, The City University of New York, New York, NY; and
| | - Giuseppe Fiorica
- Department of Biology, City College of New York, The City University of New York, New York, NY; and
| | - Genesis Michel
- Department of Biology, City College of New York, The City University of New York, New York, NY; and
| | | | - Bao Q. Vuong
- Biology PhD Program, The Graduate Center, The City University of New York, New York, NY
- Department of Biology, City College of New York, The City University of New York, New York, NY; and
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Role of Protein Kinase A Activation in the Immune System with an Emphasis on Lipopolysaccharide-Responsive and Beige-like Anchor Protein in B Cells. Int J Mol Sci 2023; 24:ijms24043098. [PMID: 36834508 PMCID: PMC9962394 DOI: 10.3390/ijms24043098] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 01/13/2023] [Accepted: 01/17/2023] [Indexed: 02/08/2023] Open
Abstract
Cyclic AMP-dependent protein kinase A (PKA) is a ubiquitous enzymatic complex that is involved in a broad spectrum of intracellular receptor signaling. The activity of PKA depends on A-kinase anchoring proteins (AKAPs) that attach to PKAs close to their substrates to control signaling. Although the relevance of PKA-AKAP signaling in the immune system is evident in T cells, its relevance in B and other immune cells remains relatively unclear. In the last decade, lipopolysaccharide-responsive and beige-like anchor protein (LRBA) has emerged as an AKAP that is ubiquitously expressed in B and T cells, specifically after activation. A deficiency of LRBA leads to immune dysregulation and immunodeficiency. The cellular mechanisms regulated by LRBA have not yet been investigated. Therefore, this review summarizes the functions of PKA in immunity and provides the most recent information regarding LRBA deficiency to deepen our understanding of immune regulation and immunological diseases.
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Luo L, Jiang P, Chen Q, Chang J, Jing Y, Luo X, Gu H, Huang Y, Chen R, Liu J, Kang D, Liu Q, Wang Y, Fang G, Zhu Y, Guan F, Lei J, Yang L, Liu C, Dai X. c-Abl controls BCR signaling and B cell differentiation by promoting B cell metabolism. Immunology 2022; 167:181-196. [PMID: 35753034 DOI: 10.1111/imm.13525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Accepted: 03/15/2022] [Indexed: 11/30/2022] Open
Abstract
As a non-receptor tyrosine kinase, c-Abl was first studied in chronic myelogenous leukemia, and its role in lymphocytes has been well characterized. c-Abl is involved in B cell development and CD19 associated B cell antigen receptor (BCR) signaling. Although c-Abl regulates different metabolic pathways, the role of c-Abl is still unknown in B cell metabolism. In this study, B cell specific c-Abl knockout (KO) mice (Mb1Cre+/- c-Ablfl/fl ) were used to investigate how c-Abl regulates B cell metabolism and BCR signaling. We found that the levels of activation positive BCR signaling proximal molecules, phosphorylated spleen tyrosine kinase (pSYK) and phosphorylated Bruton tyrosine kinase (pBTK), were decreased, while the level of key negative regulator, phosphorylated SH2-containing inositol phosphatase (pSHIP1), was increased in Mb1Cre+/- c-Ablfl/fl mice. Furthermore, we found c-Abl deficiency weakened the B cell spreading, formation of BCR signalosomes, and the polymerization of actin during BCR activation, and also impaired the differentiation of germinal center (GC) B cells both in quiescent condition and after immunization. Moreover, B cell mitochondrial respiration and the expression of B cell metabolism regulating molecules were downregulated in c-Abl deficiency mice. Overall, c-Abl, which involved in actin remodeling and B cell metabolism, positively regulates BCR signaling and promotes GC differentiation. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Li Luo
- Department of Pathogen Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Panpan Jiang
- Department of Pathogen Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qianglin Chen
- Department of Immunology, School of Medicine, Yangtze University, Jingzhou, China
| | - Jiang Chang
- Department of Pathogen Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yukai Jing
- Department of Pathogen Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xi Luo
- Department of Pathogen Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Heng Gu
- Department of Pathogen Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yanmei Huang
- Department of Pathogen Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ran Chen
- Department of Pathogen Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ju Liu
- Department of Pathogen Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Danqing Kang
- Department of Pathogen Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qi Liu
- Department of Immunology, School of Medicine, Yangtze University, Jingzhou, China
| | - Yi Wang
- Department of Pathogen Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Guofeng Fang
- Department of Pathogen Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yingzi Zhu
- Department of Pathogen Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Fei Guan
- Department of Pathogen Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jiahui Lei
- Department of Pathogen Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Lu Yang
- Department of Pathogen Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Chaohong Liu
- Department of Pathogen Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xin Dai
- Department of Pathogen Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Lougaris V, Plebani A. Predominantly Antibody Deficiencies. ENCYCLOPEDIA OF INFECTION AND IMMUNITY 2022:482-496. [DOI: 10.1016/b978-0-12-818731-9.00097-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2025]
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12
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ASTE1 promotes shieldin-complex-mediated DNA repair by attenuating end resection. Nat Cell Biol 2021; 23:894-904. [PMID: 34354233 DOI: 10.1038/s41556-021-00723-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 06/25/2021] [Indexed: 12/23/2022]
Abstract
The shieldin complex functions as the downstream effector of 53BP1-RIF1 to promote DNA double-strand break end-joining by restricting end resection. The SHLD2 subunit binds to single-stranded DNA ends and blocks end resection through OB-fold domains. Besides blocking end resection, it is unclear how the shieldin complex processes SHLD2-bound single-stranded DNA and promotes non-homologous end-joining. Here, we identify a downstream effector of the shieldin complex, ASTE1, as a structure-specific DNA endonuclease that specifically cleaves single-stranded DNA and 3' overhang DNA. ASTE1 localizes to DNA damage sites in a shieldin-dependent manner. Loss of ASTE1 impairs non-homologous end-joining, leads to hyper-resection and causes defective immunoglobulin class switch recombination. ASTE1 deficiency also causes resistance to poly(ADP-ribose) polymerase inhibitors in BRCA1-deficient cells owing to restoration of homologous recombination. These findings suggest that ASTE1-mediated 3' single-stranded DNA end cleavage contributes to the control of DSB repair choice by 53BP1, RIF1 and shieldin.
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13
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Reiman D, Manakkat Vijay GK, Xu H, Sonin A, Chen D, Salomonis N, Singh H, Khan AA. Pseudocell Tracer-A method for inferring dynamic trajectories using scRNAseq and its application to B cells undergoing immunoglobulin class switch recombination. PLoS Comput Biol 2021; 17:e1008094. [PMID: 33939691 PMCID: PMC8118552 DOI: 10.1371/journal.pcbi.1008094] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 05/13/2021] [Accepted: 03/30/2021] [Indexed: 11/19/2022] Open
Abstract
Single cell RNA sequencing (scRNAseq) can be used to infer a temporal ordering of cellular states. Current methods for the inference of cellular trajectories rely on unbiased dimensionality reduction techniques. However, such biologically agnostic ordering can prove difficult for modeling complex developmental or differentiation processes. The cellular heterogeneity of dynamic biological compartments can result in sparse sampling of key intermediate cell states. To overcome these limitations, we develop a supervised machine learning framework, called Pseudocell Tracer, which infers trajectories in pseudospace rather than in pseudotime. The method uses a supervised encoder, trained with adjacent biological information, to project scRNAseq data into a low-dimensional manifold that maps the transcriptional states a cell can occupy. Then a generative adversarial network (GAN) is used to simulate pesudocells at regular intervals along a virtual cell-state axis. We demonstrate the utility of Pseudocell Tracer by modeling B cells undergoing immunoglobulin class switch recombination (CSR) during a prototypic antigen-induced antibody response. Our results revealed an ordering of key transcription factors regulating CSR to the IgG1 isotype, including the concomitant expression of Nfkb1 and Stat6 prior to the upregulation of Bach2 expression. Furthermore, the expression dynamics of genes encoding cytokine receptors suggest a poised IL-4 signaling state that preceeds CSR to the IgG1 isotype.
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Affiliation(s)
- Derek Reiman
- University of Illinois at Chicago, Department of Bioengineering, Chicago, Illinois, United States of America
| | - Godhev Kumar Manakkat Vijay
- University of Pittsburgh, Center for Systems Immunology, Departments of Immunology and Computational and Systems Biology, Pittsburgh, Pennsylvania, United States of America
| | - Heping Xu
- Key Laboratory of Growth Regulation and Translation Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang Province, China
- Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang Province, China
| | - Andrew Sonin
- Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia
| | - Dianyu Chen
- Key Laboratory of Growth Regulation and Translation Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang Province, China
- Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang Province, China
| | - Nathan Salomonis
- Division of Biomedical Informatics, Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - Harinder Singh
- University of Pittsburgh, Center for Systems Immunology, Departments of Immunology and Computational and Systems Biology, Pittsburgh, Pennsylvania, United States of America
- * E-mail: (HS); (AAK)
| | - Aly A. Khan
- University of Chicago, Department of Pathology, Chicago, Illinois, United States of America
- * E-mail: (HS); (AAK)
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14
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ATM: Translating the DNA Damage Response to Adaptive Immunity. Trends Immunol 2021; 42:350-365. [PMID: 33663955 DOI: 10.1016/j.it.2021.02.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 01/22/2021] [Accepted: 02/01/2021] [Indexed: 12/20/2022]
Abstract
ATM is often dubbed the master regulator of the DNA double stranded break (DSB) response. Since proper induction and repair of DNA DSBs forms the core of immunological diversity, it is surprising that patients with ataxia telangiectasia generally have a mild immunodeficiency in contrast to other DSB repair syndromes. In this review, we address this discrepancy by delving into the functions of ATM in DSB repair and cell cycle control and translate these to adaptive immunity. We conclude that ATM, despite its myriad functions, is not an absolute requirement for acquiring sufficient levels of immunological diversity to prevent severe viral and opportunistic infections. There is, however, a more clinically pronounced antibody deficiency in ataxia telangiectasia due to disturbed class switch recombination.
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15
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Jiang Y, Dong Y, Luo Y, Jiang S, Meng FL, Tan M, Li J, Zang Y. AMPK-mediated phosphorylation on 53BP1 promotes c-NHEJ. Cell Rep 2021; 34:108713. [PMID: 33596428 DOI: 10.1016/j.celrep.2021.108713] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 11/12/2020] [Accepted: 01/12/2021] [Indexed: 12/25/2022] Open
Abstract
AMP-activated protein kinase (AMPK) is an energy sensor that plays roles in multiple biological processes beyond metabolism. Several studies have suggested that AMPK is involved in the DNA damage response (DDR), but the mechanisms remain unclear. Herein, we demonstrate that AMPK promotes classic non-homologous end joining (c-NHEJ) in double-strand break (DSB) repair through recruiting a key chromatin-based mediator named p53-binding protein 1 (53BP1), which facilitates the end joining of distal DNA ends during DDR. We find that the interaction of AMPK and 53BP1 spatially occurs under DSB stress. In the context of DSBs, AMPK directly phosphorylates 53BP1 at Ser1317 and promotes 53BP1 recruitment during DDR for an efficient c-NHEJ, thus maintaining genomic stability and diversity of the immune repertoire. Taken together, our study demonstrates that AMPK is a regulator of 53BP1 and controls c-NHEJ choice by phospho-regulation.
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Affiliation(s)
- Yuejing Jiang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; University of Chinese Academy of Sciences, No. 19(A) Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Ying Dong
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; University of Chinese Academy of Sciences, No. 19(A) Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Yifeng Luo
- University of Chinese Academy of Sciences, No. 19(A) Yuquan Road, Shijingshan District, Beijing 100049, China; 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, 320 Yueyang Road, Shanghai 200031, China
| | - Shangwen Jiang
- Chemical Proteomics Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Fei-Long Meng
- University of Chinese Academy of Sciences, No. 19(A) Yuquan Road, Shijingshan District, Beijing 100049, China; 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, 320 Yueyang Road, Shanghai 200031, China
| | - Minjia Tan
- University of Chinese Academy of Sciences, No. 19(A) Yuquan Road, Shijingshan District, Beijing 100049, China; Chemical Proteomics Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Jia Li
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; University of Chinese Academy of Sciences, No. 19(A) Yuquan Road, Shijingshan District, Beijing 100049, China; Open Studio for Druggability Research of Marine Natural Products, Pilot National Laboratory for Marine Science and Technology (Qingdao), 1 Wenhai Road, Aoshanwei, Jimo, Qingdao 266237, China; School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310024, China.
| | - Yi Zang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; University of Chinese Academy of Sciences, No. 19(A) Yuquan Road, Shijingshan District, Beijing 100049, China; School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310024, China.
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16
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Gong R, Wu J, Jin Y, Chen T. Defective Toll-Like Receptors Driven B Cell Response in Hyper IgE Syndrome Patients With STAT3 Mutations. Front Pediatr 2021; 9:738799. [PMID: 34805040 PMCID: PMC8604043 DOI: 10.3389/fped.2021.738799] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 10/05/2021] [Indexed: 01/26/2023] Open
Abstract
Autosomal dominant hyper-IgE syndrome (AD-HIES) is a rare inherited primary immunodeficient disease (PIDs), which is caused by STAT3 gene mutations. Previous studies indicated a defective Toll-like receptor (TLR) 9-induced B cell response in AD-HIES patients, including proliferation, and IgG production. However, the other TLRs-mediated B cell responses in AD-HIES patients were not fully elucidated. In this study, we systematically studied the B cell response to TLRs signaling pathways in AD-HIES patients, including proliferation, activation, apoptosis, cytokine, and immunoglobulin production. Our results showed that the TLRs-induced B cell proliferation and activation was significantly impaired in AD-HIES patients. Besides, AD-HIES patients had defects in TLRs-induced B cell class switch, as well as IgG/IgM secretion and IL-10 production in B cells. Taken together, we first systematically reported the deficiency of TLRs driven B cell response in AD-HIES patients, which help to have a better understanding of the pathology of AD-HIES.
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Affiliation(s)
- Ruolan Gong
- Division of Immunology, Institute of Pediatric Translational Medicine, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Jing Wu
- Division of Immunology, Institute of Pediatric Translational Medicine, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Allergy/Immunology Innovation Team, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yingying Jin
- Allergy/Immunology Innovation Team, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Department of Rheumatology/Immunology, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Tongxin Chen
- Division of Immunology, Institute of Pediatric Translational Medicine, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Allergy/Immunology Innovation Team, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Department of Rheumatology/Immunology, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
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17
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Brochu HN, Tseng E, Smith E, Thomas MJ, Jones AM, Diveley KR, Law L, Hansen SG, Picker LJ, Gale M, Peng X. Systematic Profiling of Full-Length Ig and TCR Repertoire Diversity in Rhesus Macaque through Long Read Transcriptome Sequencing. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2020; 204:3434-3444. [PMID: 32376650 PMCID: PMC7276939 DOI: 10.4049/jimmunol.1901256] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 04/13/2020] [Indexed: 12/19/2022]
Abstract
The diversity of Ig and TCR repertoires is a focal point of immunological studies. Rhesus macaques (Macaca mulatta) are key for modeling human immune responses, placing critical importance on the accurate annotation and quantification of their Ig and TCR repertoires. However, because of incomplete reference resources, the coverage and accuracy of the traditional targeted amplification strategies for profiling rhesus Ig and TCR repertoires are largely unknown. In this study, using long read sequencing, we sequenced four Indian-origin rhesus macaque tissues and obtained high-quality, full-length sequences for over 6000 unique Ig and TCR transcripts, without the need for sequence assembly. We constructed, to our knowledge, the first complete reference set for the constant regions of all known isotypes and chain types of rhesus Ig and TCR repertoires. We show that sequence diversity exists across the entire variable regions of rhesus Ig and TCR transcripts. Consequently, existing strategies using targeted amplification of rearranged variable regions comprised of V(D)J gene segments miss a significant fraction (27-53% and 42-49%) of rhesus Ig/TCR diversity. To overcome these limitations, we designed new rhesus-specific assays that remove the need for primers conventionally targeting variable regions and allow single cell level Ig and TCR repertoire analysis. Our improved approach will enable future studies to fully capture rhesus Ig and TCR repertoire diversity and is applicable for improving annotations in any model organism.
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Affiliation(s)
- Hayden N Brochu
- Department of Molecular Biomedical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, NC 27607
- Bioinformatics Graduate Program, North Carolina State University, Raleigh, NC 27695
| | | | - Elise Smith
- Department of Immunology, University of Washington, Seattle, WA 98109
| | - Matthew J Thomas
- Department of Immunology, University of Washington, Seattle, WA 98109
- Center for Innate Immunity and Immune Diseases, University of Washington, Seattle, WA 98109
| | - Aiden M Jones
- Department of Molecular Biomedical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, NC 27607
- Genetics Graduate Program, North Carolina State University, Raleigh, NC 27695
| | - Kayleigh R Diveley
- Department of Molecular Biomedical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, NC 27607
- Genetics Graduate Program, North Carolina State University, Raleigh, NC 27695
| | - Lynn Law
- Department of Immunology, University of Washington, Seattle, WA 98109
- Center for Innate Immunity and Immune Diseases, University of Washington, Seattle, WA 98109
| | - Scott G Hansen
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, OR 97006
| | - Louis J Picker
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, OR 97006
| | - Michael Gale
- Department of Immunology, University of Washington, Seattle, WA 98109
- Center for Innate Immunity and Immune Diseases, University of Washington, Seattle, WA 98109
- Washington National Primate Research Center, University of Washington, Seattle, WA 98121; and
| | - Xinxia Peng
- Department of Molecular Biomedical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, NC 27607;
- Bioinformatics Graduate Program, North Carolina State University, Raleigh, NC 27695
- Bioinformatics Research Center, North Carolina State University, Raleigh, NC 27695
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18
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Xu H, Ding J, Porter CBM, Wallrapp A, Tabaka M, Ma S, Fu S, Guo X, Riesenfeld SJ, Su C, Dionne D, Nguyen LT, Lefkovith A, Ashenberg O, Burkett PR, Shi HN, Rozenblatt-Rosen O, Graham DB, Kuchroo VK, Regev A, Xavier RJ. Transcriptional Atlas of Intestinal Immune Cells Reveals that Neuropeptide α-CGRP Modulates Group 2 Innate Lymphoid Cell Responses. Immunity 2020; 51:696-708.e9. [PMID: 31618654 DOI: 10.1016/j.immuni.2019.09.004] [Citation(s) in RCA: 193] [Impact Index Per Article: 38.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 08/06/2019] [Accepted: 09/06/2019] [Indexed: 12/17/2022]
Abstract
Signaling abnormalities in immune responses in the small intestine can trigger chronic type 2 inflammation involving interaction of multiple immune cell types. To systematically characterize this response, we analyzed 58,067 immune cells from the mouse small intestine by single-cell RNA sequencing (scRNA-seq) at steady state and after induction of a type 2 inflammatory reaction to ovalbumin (OVA). Computational analysis revealed broad shifts in both cell-type composition and cell programs in response to the inflammation, especially in group 2 innate lymphoid cells (ILC2s). Inflammation induced the expression of exon 5 of Calca, which encodes the alpha-calcitonin gene-related peptide (α-CGRP), in intestinal KLRG1+ ILC2s. α-CGRP antagonized KLRG1+ ILC2s proliferation but promoted IL-5 expression. Genetic perturbation of α-CGRP increased the proportion of intestinal KLRG1+ ILC2s. Our work highlights a model where α-CGRP-mediated neuronal signaling is critical for suppressing ILC2 expansion and maintaining homeostasis of the type 2 immune machinery.
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Affiliation(s)
- Heping Xu
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou 310024, Zhejiang Province, China; Laboratory of Systems Immunology, Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou 310024, Zhejiang Province, China.
| | - Jiarui Ding
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | | | - Antonia Wallrapp
- Evergrande Center for Immunologic Diseases, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02114, USA
| | - Marcin Tabaka
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Sai Ma
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Shujie Fu
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou 310024, Zhejiang Province, China; Laboratory of Systems Immunology, Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou 310024, Zhejiang Province, China
| | - Xuanxuan Guo
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou 310024, Zhejiang Province, China; Laboratory of Systems Immunology, Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou 310024, Zhejiang Province, China
| | | | - Chienwen Su
- Mucosal Immunology and Biology Research Center, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Danielle Dionne
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Lan T Nguyen
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Ariel Lefkovith
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Orr Ashenberg
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Patrick R Burkett
- Evergrande Center for Immunologic Diseases, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02114, USA
| | - Hai Ning Shi
- Mucosal Immunology and Biology Research Center, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | | | - Daniel B Graham
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA; Gastrointestinal Unit and Center for the Study of Inflammatory Bowel Disease, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA; Center for Microbiome Informatics and Therapeutics, Massachusetts Institute of Technology, Cambridge, MA 02114, USA
| | - Vijay K Kuchroo
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Evergrande Center for Immunologic Diseases, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02114, USA
| | - Aviv Regev
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Howard Hughes Medical Institute and Koch Institute for Integrative Cancer Research, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.
| | - Ramnik J Xavier
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA; Gastrointestinal Unit and Center for the Study of Inflammatory Bowel Disease, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA; Center for Microbiome Informatics and Therapeutics, Massachusetts Institute of Technology, Cambridge, MA 02114, USA; Center for Computational and Integrative Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
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19
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Regulation of long non-coding RNAs and genome dynamics by the RNA surveillance machinery. Nat Rev Mol Cell Biol 2020; 21:123-136. [PMID: 32020081 DOI: 10.1038/s41580-019-0209-0] [Citation(s) in RCA: 149] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/19/2019] [Indexed: 02/07/2023]
Abstract
Much of the mammalian genome is transcribed, generating long non-coding RNAs (lncRNAs) that can undergo post-transcriptional surveillance whereby only a subset of the non-coding transcripts is allowed to attain sufficient stability to persist in the cellular milieu and control various cellular functions. Paralleling protein turnover by the proteasome complex, lncRNAs are also likely to exist in a dynamic equilibrium that is maintained through constant monitoring by the RNA surveillance machinery. In this Review, we describe the RNA surveillance factors and discuss the vital role of lncRNA surveillance in orchestrating various biological processes, including the protection of genome integrity, maintenance of pluripotency of embryonic stem cells, antibody-gene diversification, coordination of immune cell activation and regulation of heterochromatin formation. We also discuss examples of human diseases and developmental defects associated with the failure of RNA surveillance mechanisms, further highlighting the importance of lncRNA surveillance in maintaining cell and organism functions and health.
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20
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Lambert JM, Srour N, Delpy L. The Yin and Yang of RNA surveillance in B lymphocytes and antibody-secreting plasma cells. BMB Rep 2019. [PMID: 31619318 PMCID: PMC6941761 DOI: 10.5483/bmbrep.2019.52.12.232] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The random V(D)J recombination process ensures the diversity of the primary immunoglobulin (Ig) repertoire. In two thirds of cases, imprecise recombination between variable (V), diversity (D), and joining (J) segments induces a frameshift in the open reading frame that leads to the appearance of premature termination codons (PTCs). Thus, many B lineage cells harbour biallelic V(D)J-rearrangements of Ig heavy or light chain genes, with a productively-recombined allele encoding the functional Ig chain and a nonproductive allele potentially encoding truncated Ig polypeptides. Since the pattern of Ig gene expression is mostly biallelic, transcription initiated from nonproductive Ig alleles generates considerable amounts of primary transcripts with out-of-frame V(D)J junctions. How RNA surveillance pathways cooperate to control the noise from nonproductive Ig genes will be discussed in this review, focusing on the benefits of nonsense-mediated mRNA decay (NMD) activation during B-cell development and detrimental effects of nonsense-associated altered splicing (NAS) in terminally differentiated plasma cells.
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Affiliation(s)
- Jean-Marie Lambert
- UMR CNRS 7276 - INSERM 1268 - Université de Limoges, Centre de Biologie et de Recherche en Santé, 2 rue du Dr Marcland, Limoges F-87025, France
| | - Nivine Srour
- UMR CNRS 7276 - INSERM 1268 - Université de Limoges, Centre de Biologie et de Recherche en Santé, 2 rue du Dr Marcland, Limoges F-87025, France
| | - Laurent Delpy
- UMR CNRS 7276 - INSERM 1268 - Université de Limoges, Centre de Biologie et de Recherche en Santé, 2 rue du Dr Marcland, Limoges F-87025, France
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21
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Auladell M, Jia X, Hensen L, Chua B, Fox A, Nguyen THO, Doherty PC, Kedzierska K. Recalling the Future: Immunological Memory Toward Unpredictable Influenza Viruses. Front Immunol 2019; 10:1400. [PMID: 31312199 PMCID: PMC6614380 DOI: 10.3389/fimmu.2019.01400] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 06/03/2019] [Indexed: 01/09/2023] Open
Abstract
Persistent and durable immunological memory forms the basis of any successful vaccination protocol. Generation of pre-existing memory B cell and T cell pools is thus the key for maintaining protective immunity to seasonal, pandemic and avian influenza viruses. Long-lived antibody secreting cells (ASCs) are responsible for maintaining antibody levels in peripheral blood. Generated with CD4+ T help after naïve B cell precursors encounter their cognate antigen, the linked processes of differentiation (including Ig class switching) and proliferation also give rise to memory B cells, which then can change rapidly to ASC status after subsequent influenza encounters. Given that influenza viruses evolve rapidly as a consequence of antibody-driven mutational change (antigenic drift), the current influenza vaccines need to be reformulated frequently and annual vaccination is recommended. Without that process of regular renewal, they provide little protection against “drifted” (particularly H3N2) variants and are mainly ineffective when a novel pandemic (2009 A/H1N1 “swine” flu) strain suddenly emerges. Such limitation of antibody-mediated protection might be circumvented, at least in part, by adding a novel vaccine component that promotes cross-reactive CD8+ T cells specific for conserved viral peptides, presented by widely distributed HLA types. Such “memory” cytotoxic T lymphocytes (CTLs) can rapidly be recalled to CTL effector status. Here, we review how B cells and follicular T cells are elicited following influenza vaccination and how they survive into a long-term memory. We describe how CD8+ CTL memory is established following influenza virus infection, and how a robust CTL recall response can lead to more rapid virus elimination by destroying virus-infected cells, and recovery. Exploiting long-term, cross-reactive CTL against the continuously evolving and unpredictable influenza viruses provides a possible mechanism for preventing a disastrous pandemic comparable to the 1918-1919 H1N1 “Spanish flu,” which killed more than 50 million people worldwide.
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Affiliation(s)
- Maria Auladell
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia
| | - Xiaoxiao Jia
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia
| | - Luca Hensen
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia
| | - Brendon Chua
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia.,Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Annette Fox
- WHO Collaborating Centre for Reference and Research on Influenza, Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
| | - Thi H O Nguyen
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia
| | - Peter C Doherty
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia.,Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Katherine Kedzierska
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia
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22
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Pilzecker B, Jacobs H. Mutating for Good: DNA Damage Responses During Somatic Hypermutation. Front Immunol 2019; 10:438. [PMID: 30915081 PMCID: PMC6423074 DOI: 10.3389/fimmu.2019.00438] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 02/19/2019] [Indexed: 11/13/2022] Open
Abstract
Somatic hypermutation (SHM) of immunoglobulin (Ig) genes plays a key role in antibody mediated immunity. SHM in B cells provides the molecular basis for affinity maturation of antibodies. In this way SHM is key in optimizing antibody dependent immune responses. SHM is initiated by targeting the Activation-Induced Cytidine Deaminase (AID) to rearranged V(D)J and switch regions of Ig genes. The mutation rate of this programmed mutagenesis is ~10-3 base pairs per generation, a million-fold higher than the non-AID targeted genome of B cells. AID is a processive enzyme that binds single-stranded DNA and deaminates cytosines in DNA. Cytosine deamination generates highly mutagenic deoxy-uracil (U) in the DNA of both strands of the Ig loci. Mutagenic processing of the U by the DNA damage response generates the entire spectrum of base substitutions characterizing SHM at and around the initial U lesion. Starting from the U as a primary lesion, currently five mutagenic DNA damage response pathways have been identified in generating a well-defined SHM spectrum of C/G transitions, C/G transversions, and A/T mutations around this initial lesion. These pathways include (1) replication opposite template U generates transitions at C/G, (2) UNG2-dependent translesion synthesis (TLS) generates transversions at C/G, (3) a hybrid pathway comprising non-canonical mismatch repair (ncMMR) and UNG2-dependent TLS generates transversions at C/G, (4) ncMMR generates mutations at A/T, and (5) UNG2- and PCNA Ubiquitination (PCNA-Ub)-dependent mutations at A/T. Furthermore, specific strand-biases of SHM spectra arise as a consequence of a biased AID targeting, ncMMR, and anti-mutagenic repriming. Here, we review mammalian SHM with special focus on the mutagenic DNA damage response pathways involved in processing AID induced Us, the origin of characteristic strand biases, and relevance of the cell cycle.
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Affiliation(s)
| | - Heinz Jacobs
- Division of Tumor Biology & Immunology, The Netherlands Cancer Institute, Amsterdam, Netherlands
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Ministro J, Manuel AM, Goncalves J. Therapeutic Antibody Engineering and Selection Strategies. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2019; 171:55-86. [PMID: 31776591 DOI: 10.1007/10_2019_116] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Antibody drugs became an increasingly important element of the therapeutic landscape. Their accomplishment has been driven by many unique properties, in particular by their very high specificity and selectivity, in contrast to the off-target liabilities of small molecules (SMs). Antibodies can bring additional functionality to the table with their ability to interact with the immune system, and this can be further manipulated with advances in antibody engineering.The expansion of strategies related to discovery technologies of monoclonal antibodies (mAbs) (phage display, yeast display, ribosome display, bacterial display, mammalian cell surface display, mRNA display, DNA display, transgenic animal, and human B cell derived) opened perspectives for the screening and the selection of therapeutic antibodies for, theoretically, any target from any kind of organism. Moreover, antibody engineering technologies were developed and explored to obtain chosen characteristics of selected leading candidates such as high affinity, low immunogenicity, improved functionality, improved protein production, improved stability, and others. This chapter contains an overview of discovery technologies, mainly display methods and antibody humanization methods for the selection of therapeutic humanized and human mAbs that appeared along the development of these technologies and thereafter. The increasing applications of these technologies will be highlighted in the antibody engineering area (affinity maturation, guided selection to obtain human antibodies) giving promising perspectives for the development of future therapeutics.
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Affiliation(s)
| | - Ana Margarida Manuel
- iMed - Research Institute for Medicines, Faculty of Pharmacy at University of Lisbon, Lisbon, Portugal
| | - Joao Goncalves
- iMed - Research Institute for Medicines, Faculty of Pharmacy at University of Lisbon, Lisbon, Portugal.
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Abstract
Immunoglobulin (IG) gene remodeling by V(D)J recombination plays a central role in the generation of normal B cells, and somatic hypermutation and class switching of IG genes are key processes during antigen-driven B cell differentiation. However, errors of these processes are involved in the development of B cell lymphomas. IG locus-associated translocations of proto-oncogenes are a hallmark of many B cell malignancies. Additional transforming events include inactivating mutations in various tumor suppressor genes and also latent infection of B cells with viruses, such as Epstein-Barr virus. Many B cell lymphomas require B cell antigen receptor expression, and in several instances, chronic antigenic stimulation plays a role in lymphoma development and/or sustaining tumor growth. Often, survival and proliferation signals provided by other cells in the microenvironment are a further critical factor in lymphoma development and pathophysiology. Many B cell malignancies derive from germinal center B cells, most likely because of the high proliferation rate of these cells and the high activity of mutagenic processes.
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25
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Epidemiology, pathogenesis, molecular characteristics, classification and prognosis of the diffuse large B-cell lymphoma. Fam Med 2018. [DOI: 10.30841/2307-5112.5.2018.165327] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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26
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Brennecke AM, Düber S, Roy B, Thomsen I, Garbe AI, Klawonn F, Pabst O, Kretschmer K, Weiss S. Induced B Cell Development in Adult Mice. Front Immunol 2018; 9:2483. [PMID: 30429851 PMCID: PMC6220648 DOI: 10.3389/fimmu.2018.02483] [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: 06/01/2018] [Accepted: 10/08/2018] [Indexed: 11/30/2022] Open
Abstract
We employed the B-Indu-Rag1 model in which the coding exon of recombination-activating gene 1 (Rag1) is inactivated by inversion. It is flanked by inverted loxP sites. Accordingly, B cell development is stopped at the pro/pre B-I cell precursor stage. A B cell-specific Cre recombinase fused to a mutated estrogen receptor allows the induction of RAG1 function and B cell development by application of Tamoxifen. Since Rag1 function is recovered in a non-self-renewing precursor cell, only single waves of development can be induced. Using this system, we could determine that B cells minimally require 5 days to undergo development from pro/preB-I cells to the large and 6 days to the small preB-II cell stage. First immature transitional (T) 1 and T2 B cells could be detected in the bone marrow at day 6 and day 7, respectively, while their appearance in the spleen took one additional day. We also tested a contribution of adult bone marrow to the pool of B-1 cells. Sublethally irradiated syngeneic WT mice were adoptively transferred with bone marrow of B-Indu-Rag1 mice and B cell development was induced after 6 weeks. A significant portion of donor derived B-1 cells could be detected in such adult mice. Finally, early VH gene usage was tested after induction of B cell development. During the earliest time points the VH genes proximal to D/J were found to be predominantly rearranged. At later time points, the large family of the most distal VH prevailed.
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Affiliation(s)
| | - Sandra Düber
- Molecular Immunology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Bishnudeo Roy
- Molecular Immunology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Irene Thomsen
- Medical School Hannover, Institute of Immunology, Hannover, Germany
| | - Annette I Garbe
- Molecular Immunology, Helmholtz Centre for Infection Research, Braunschweig, Germany.,Osteoimmunology, DFG-Center for Regenerative Therapies Dresden, Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Dresden, Germany
| | - Frank Klawonn
- Biostatistics Group, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Oliver Pabst
- Medical School Hannover, Institute of Immunology, Hannover, Germany.,Institute of Molecular Medicine, RWTH Aachen University, Aachen, Germany
| | - Karsten Kretschmer
- Molecular Immunology, Helmholtz Centre for Infection Research, Braunschweig, Germany.,Molecular and Cellular Immunology/Immune Regulation, DFG-Center for Regenerative Therapies Dresden, Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Dresden, Germany
| | - Siegfried Weiss
- Molecular Immunology, Helmholtz Centre for Infection Research, Braunschweig, Germany.,Medical School Hannover, Institute of Immunology, Hannover, Germany
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A Single Locus Controls Interferon Gamma-Independent Antiretroviral Neutralizing Antibody Responses. J Virol 2018; 92:JVI.00725-18. [PMID: 29875252 DOI: 10.1128/jvi.00725-18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 06/01/2018] [Indexed: 11/20/2022] Open
Abstract
An essential step in the development of effective antiviral humoral responses is cytokine-triggered class switch recombination resulting in the production of antibodies of a specific isotype. Most viral and parasitic infections in mice induce predominantly IgG2a-specific antibody responses that are stimulated by interferon gamma (IFN-γ). However, in some mice deficient in IFN-γ, class switching to IgG2a antibodies is relatively unaffected, indicating that another signal(s) can be generated upon viral or parasitic infections that trigger this response. Here, we found that a single recessive locus, provisionally called IFN-γ-independent IgG2a (Igii), confers the ability to produce IFN-γ-independent production of IgG2a antibodies upon retroviral infection. The Igii locus was mapped to chromosome 9 and was found to function in the radiation-resistant compartment. Thus, our data implicate nonhematopoietic cells in activation of antiviral antibody responses in the absence of IFN-γ.IMPORTANCE Understanding the signals that stimulate antibody production and class switch recombination to specific antibody isotypes is crucial for the development of novel vaccines and adjuvants. While an interferon gamma-mediated switch to the IgG2a isotype upon viral infection in mice has been well established, this investigation reveals a noncanonical, interferon gamma-independent pathway for antiretroviral antibody production and IgG2a class switch recombination that is controlled by a single recessive locus. Furthermore, this study indicates that the radiation-resistant compartment can direct antiviral antibody responses, suggesting that detection of infection by nonhematopoietic cells is involved is stimulating adaptive immunity.
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Morman RE, Schweickert PG, Konieczny SF, Taparowsky EJ. BATF regulates the expression of Nfil3, Wnt10a and miR155hg for efficient induction of antibody class switch recombination in mice. Eur J Immunol 2018; 48:1492-1505. [PMID: 29898247 DOI: 10.1002/eji.201747360] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 05/14/2018] [Accepted: 06/08/2018] [Indexed: 12/16/2022]
Abstract
BATF functions in T cells and B cells to control the host response to antigen and promote the production of class switched immunoglobulins. In this study, we demonstrate that BATF expression increases rapidly, and transiently, following B cell stimulation and use an inducible murine model of BATF deletion to show that this induction is necessary, and sufficient, for immunoglobulin (Ig) class switch recombination (CSR). We examine two genes (Nfil3 and miR155gh) that are positively regulated, and one gene (Wnt10a) that is negatively regulated by BATF during CSR. These genes play essential roles in CSR and each impacts the expression and/or function of the others. Our observations allow these targets of BATF regulation to be positioned in a network upstream of the activation of germline transcripts (GLT) from the IgH locus and of transcriptional activation of Aicda - the gene encoding the enzyme directing Ig gene rearrangements. This work extends the knowledge of the molecular control of CSR and, importantly, positions the induction and function of BATF as an early event in this process.
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Affiliation(s)
- Rosemary E Morman
- Department of Biological Sciences and Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN, USA
| | - Patrick G Schweickert
- Department of Biological Sciences and Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN, USA
| | - Stephen F Konieczny
- Department of Biological Sciences and Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN, USA
| | - Elizabeth J Taparowsky
- Department of Biological Sciences and Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN, USA
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Choudhary M, Tamrakar A, Singh AK, Jain M, Jaiswal A, Kodgire P. AID Biology: A pathological and clinical perspective. Int Rev Immunol 2017; 37:37-56. [PMID: 28933967 DOI: 10.1080/08830185.2017.1369980] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Activation-induced cytidine deaminase (AID), primarily expressed in activated mature B lymphocytes in germinal centers, is the key factor in adaptive immune response against foreign antigens. AID is responsible for producing high-affinity and high-specificity antibodies against an infectious agent, through the physiological DNA alteration processes of antibody genes by somatic hypermutation (SHM) and class-switch recombination (CSR) and functions by deaminating deoxycytidines (dC) to deoxyuridines (dU), thereby introducing point mutations and double-stranded chromosomal breaks (DSBs). The beneficial physiological role of AID in antibody diversification is outweighed by its detrimental role in the genesis of several chronic immune diseases, under non-physiological conditions. This review offers a comprehensive and better understanding of AID biology and its pathological aspects, as well as addresses the challenges involved in AID-related cancer therapeutics, based on various recent advances and evidence available in the literature till date. In this article, we discuss ways through which our interpretation of AID biology may reflect upon novel clinical insights, which could be successfully translated into designing clinical trials and improving patient prognosis and disease management.
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Affiliation(s)
- Meenal Choudhary
- a Centre for Biosciences and Biomedical Engineering , Indian Institute of Technology Indore , Simrol , Indore , Madhya Pradesh , India
| | - Anubhav Tamrakar
- a Centre for Biosciences and Biomedical Engineering , Indian Institute of Technology Indore , Simrol , Indore , Madhya Pradesh , India
| | - Amit Kumar Singh
- a Centre for Biosciences and Biomedical Engineering , Indian Institute of Technology Indore , Simrol , Indore , Madhya Pradesh , India
| | - Monika Jain
- a Centre for Biosciences and Biomedical Engineering , Indian Institute of Technology Indore , Simrol , Indore , Madhya Pradesh , India
| | - Ankit Jaiswal
- a Centre for Biosciences and Biomedical Engineering , Indian Institute of Technology Indore , Simrol , Indore , Madhya Pradesh , India
| | - Prashant Kodgire
- a Centre for Biosciences and Biomedical Engineering , Indian Institute of Technology Indore , Simrol , Indore , Madhya Pradesh , India
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30
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Gupta S, Gupta A. Selective IgM Deficiency-An Underestimated Primary Immunodeficiency. Front Immunol 2017; 8:1056. [PMID: 28928736 PMCID: PMC5591887 DOI: 10.3389/fimmu.2017.01056] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 08/14/2017] [Indexed: 11/18/2022] Open
Abstract
Although selective IgM deficiency (SIGMD) was described almost five decades ago, it was largely ignored as a primary immunodeficiency. SIGMD is defined as serum IgM levels below two SD of mean with normal serum IgG and IgA. It appears to be more common than originally realized. SIGMD is observed in both children and adults. Patients with SIGMD may be asymptomatic; however, approximately 80% of patients with SIGMD present with infections with bacteria, viruses, fungi, and protozoa. There is an increased frequency of allergic and autoimmune diseases in SIGMD. A number of B cell subset abnormalities have been reported and impaired specific antibodies to Streptococcus pneumoniae responses are observed in more than 45% of cases. Innate immunity, T cells, T cell subsets, and T cell functions are essentially normal. The pathogenesis of SIGMD remains unclear. Mice selectively deficient in secreted IgM are also unable to control infections from bacterial, viral, and fungal pathogens, and develop autoimmunity. Immunological and clinical similarities and differences between mouse models of deficiency of secreted IgM and humans with SIGMD have been discussed. Patients with SIGMD presenting with recurrent infections and specific antibody deficiency responses appear to improve clinically on immunoglobulin therapy.
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Affiliation(s)
- Sudhir Gupta
- Program in Primary Immunodeficiency and Aging, Division of Basic and Clinical Immunology, University of California at Irvine, Irvine, CA, United States
| | - Ankmalika Gupta
- Program in Primary Immunodeficiency and Aging, Division of Basic and Clinical Immunology, University of California at Irvine, Irvine, CA, United States
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31
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Deng J, Lü S, Liu H, Liu B, Jiang C, Xu Q, Feng J, Wang X. Homocysteine Activates B Cells via Regulating PKM2-Dependent Metabolic Reprogramming. THE JOURNAL OF IMMUNOLOGY 2016; 198:170-183. [PMID: 27903739 DOI: 10.4049/jimmunol.1600613] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 10/24/2016] [Indexed: 01/16/2023]
Abstract
The overactivation of immune cells plays an important role in the pathogenesis of hyperhomocysteinemia (HHcy)-accelerated atherosclerosis. Homocysteine (Hcy) activates B cell proliferation and Ab secretion; however, the underlying mechanisms for these effects remain largely unknown. Metabolic reprogramming is critical for lymphocyte activation and effector function. In this study, we showed that Hcy-activated B cells displayed an increase in both oxidative phosphorylation and glycolysis, with a tendency to shift toward the latter, as well as an accumulation of intermediates in the pentose phosphate pathway, to provide energy and biosynthetic substrates for cell growth and function. Mechanistically, Hcy increased both the protein expression and glycolytic enzyme activity of the pyruvate kinase muscle isozyme 2 (PKM2) in B cells, whereas the PKM2 inhibitor shikonin restored Hcy-induced metabolic changes, as well as B cell proliferation and Ab secretion both in vivo and in vitro, indicating that PKM2 plays a critical role in metabolic reprogramming in Hcy-activated B cells. Further investigation revealed that the Akt-mechanistic target of rapamycin signaling pathway was involved in this process, as the mechanistic target of rapamycin inhibitor rapamycin inhibited Hcy-induced changes in PKM2 enzyme activity and B cell activation. Notably, shikonin treatment effectively attenuated HHcy-accelerated atherosclerotic lesion formation in apolipoprotein E-deficient mice. In conclusion, our results demonstrate that PKM2 is required to support metabolic reprogramming for Hcy-induced B cell activation and function, and it might serve as a critical regulator in HHcy-accelerated initiation of atherosclerosis.
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Affiliation(s)
- Jiacheng Deng
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, People's Republic of China; and
| | - Silin Lü
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, People's Republic of China; and
| | - Huiying Liu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, People's Republic of China; and
| | - Bo Liu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, People's Republic of China; and
| | - Changtao Jiang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, People's Republic of China; and
| | - Qingbo Xu
- Cardiovascular Division, British Heart Foundation Centre for Vascular Regeneration, King's College London, London SE5 9NU, United Kingdom
| | - Juan Feng
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, People's Republic of China; and
| | - Xian Wang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, People's Republic of China; and
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Massaad MJ, Zhou J, Tsuchimoto D, Chou J, Jabara H, Janssen E, Glauzy S, Olson BG, Morbach H, Ohsumi TK, Schmitz K, Kyriacos M, Kane J, Torisu K, Nakabeppu Y, Notarangelo LD, Chouery E, Megarbane A, Kang PB, Al-Idrissi E, Aldhekri H, Meffre E, Mizui M, Tsokos GC, Manis JP, Al-Herz W, Wallace SS, Geha RS. Deficiency of base excision repair enzyme NEIL3 drives increased predisposition to autoimmunity. J Clin Invest 2016; 126:4219-4236. [PMID: 27760045 DOI: 10.1172/jci85647] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 09/06/2016] [Indexed: 12/17/2022] Open
Abstract
Alterations in the apoptosis of immune cells have been associated with autoimmunity. Here, we have identified a homozygous missense mutation in the gene encoding the base excision repair enzyme Nei endonuclease VIII-like 3 (NEIL3) that abolished enzymatic activity in 3 siblings from a consanguineous family. The NEIL3 mutation was associated with fatal recurrent infections, severe autoimmunity, hypogammaglobulinemia, and impaired B cell function in these individuals. The same homozygous NEIL3 mutation was also identified in an asymptomatic individual who exhibited elevated levels of serum autoantibodies and defective peripheral B cell tolerance, but normal B cell function. Further analysis of the patients revealed an absence of LPS-responsive beige-like anchor (LRBA) protein expression, a known cause of immunodeficiency. We next examined the contribution of NEIL3 to the maintenance of self-tolerance in Neil3-/- mice. Although Neil3-/- mice displayed normal B cell function, they exhibited elevated serum levels of autoantibodies and developed nephritis following treatment with poly(I:C) to mimic microbial stimulation. In Neil3-/- mice, splenic T and B cells as well as germinal center B cells from Peyer's patches showed marked increases in apoptosis and cell death, indicating the potential release of self-antigens that favor autoimmunity. These findings demonstrate that deficiency in NEIL3 is associated with increased lymphocyte apoptosis, autoantibodies, and predisposition to autoimmunity.
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Lyalina T, Zubareva A, Varlamov V, Svirshchevskaya E. Cross-presentation of lactoferrin encapsulated into chitosan-based nanoparticles. Nanobiomedicine (Rij) 2016; 3:1849543516667355. [PMID: 29942386 PMCID: PMC5998264 DOI: 10.1177/1849543516667355] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Accepted: 08/11/2016] [Indexed: 12/20/2022] Open
Abstract
Induction of CD8+ cytotoxic T-cell response is essential for the protection from intracellular pathogens. It requires major histocompatibility complex class I processing of newly synthesized proteins transported from the cytosolic pathway. Presentation of mature soluble proteins occurs via a cross-presentation (CP) pathway that is much less efficient in the activation of cytotoxic response. Encapsulation of proteins into polymeric nanoparticles (NPs) can modulate the efficacy of antigen CP. In this article, a model antigen lactoferrin (L) was encapsulated into polysaccharide NPs with different physicochemical properties (size, charge, and hydrophobicity) and used as an immunogen. CD8+ or CD4+ associated IgG2a or IgG1 subclasses of L-specific antibodies, respectively, served as a measure of CD8+ versus CD4+ T-cell activation. Among five types of NPs produced, only succinylchitosan–galactomannan (LSG) and succinylchitosan–PEG-chitosan (LSPC) NPs induced a significant IgG2a response. IgG1 production was comparable in all but hydrophobic succinyl-dodecyl-chitosan (LSD) NPs, where it was only marginal. Confocal studies demonstrated that galactomannan-equipped LSG-NPs induced vacuolar type of CP, while positively charged LSPC-NPs were transported mostly via the cytosolic CP pathway.
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Affiliation(s)
- Tatiana Lyalina
- Enzyme engineering laboratory, Institute of Bioengineering, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russian Federation
| | - Anastasia Zubareva
- Enzyme engineering laboratory, Institute of Bioengineering, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russian Federation
| | - Valery Varlamov
- Enzyme engineering laboratory, Institute of Bioengineering, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russian Federation
| | - Elena Svirshchevskaya
- Immunology Department, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Moscow, Russian Federation
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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: 0.9] [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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De Winter LM, Geusens P, Lenaerts J, Vanhoof J, Stinissen P, Somers V. The isotype repertoire of antibodies against novel UH-RA peptides in rheumatoid arthritis. Arthritis Res Ther 2016; 18:130. [PMID: 27267896 PMCID: PMC4896030 DOI: 10.1186/s13075-016-1030-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 05/20/2016] [Indexed: 12/25/2022] Open
Abstract
Background Recently, autoantibodies against novel UH-RA peptides (UH-RA.1 and UH-RA.21) were identified as candidate biomarkers for patients with rheumatoid arthritis (RA) who are seronegative for the current diagnostic markers rheumatoid factor and anticitrullinated protein antibodies. Previously, screening for anti-UH-RA autoantibodies was based on measuring the immunoglobulin (Ig) G response. We aimed to investigate whether measurement of other isotypes could improve the performance of diagnostic testing. In addition, assigning the isotype profile might provide valuable information on effector functions of the antibodies. Methods The isotype profile of antibodies against UH-RA.1 and UH-RA.21 was studied. The IgG, IgM, and IgA classes, together with the 4 different IgG subclasses, were determined in 285 patients with RA, 88 rheumatic control subjects, and 90 healthy control subjects. Results Anti-UH-RA.1 antibodies were primarily of the IgM isotype and twice as prevalent as IgG (IgG3-dominated) and IgA. RA sensitivity when testing for anti-UH-RA.1 IgM was shown to be higher than when testing for the IgG isotype: 18 % versus 9 % sensitivity when RA specificity was set to 90 %. Within antibodies against UH-RA.21, IgG and IgA were more common than IgM. Different anti-UH-RA.21 IgG subclasses were found, with the highest prevalence found for IgG2. Combined testing for IgG and IgA slightly increased RA sensitivity of UH-RA.21-specific antibody testing to 27 % compared with solely testing for IgG (23 %). Notably, a higher number of anti-UH-RA.21 antibody isotypes was related to increased levels of erythrocyte sedimentation rate. Finally, for both antibody responses, the full antibody isotype use was demonstrated in early and seronegative disease. Conclusions The isotype distribution of anti-UH-RA.1 and anti-UH-RA.21 antibodies was successfully outlined, and, for antibodies against UH-RA.1, we found that isotype-specific testing might have implications for diagnostic testing. The exact mechanisms by which the different antibody isotypes act still have to be unraveled.
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Affiliation(s)
- Liesbeth M De Winter
- Biomedical Research Institute, Hasselt University, and School of Life Sciences, transnational University Limburg, Martelarenlaan 42, 3500, Hasselt, Belgium
| | - Piet Geusens
- Biomedical Research Institute, Hasselt University, and School of Life Sciences, transnational University Limburg, Martelarenlaan 42, 3500, Hasselt, Belgium.,ReumaClinic, Genk, Belgium.,Rheumatology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Jan Lenaerts
- Reuma Instituut, Hasselt, Belgium.,Jessa Hospitals, Hasselt, Belgium
| | | | - Piet Stinissen
- Biomedical Research Institute, Hasselt University, and School of Life Sciences, transnational University Limburg, Martelarenlaan 42, 3500, Hasselt, Belgium
| | - Veerle Somers
- Biomedical Research Institute, Hasselt University, and School of Life Sciences, transnational University Limburg, Martelarenlaan 42, 3500, Hasselt, Belgium.
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36
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Related Mechanisms of Antibody Somatic Hypermutation and Class Switch Recombination. Microbiol Spectr 2016; 3:MDNA3-0037-2014. [PMID: 26104555 DOI: 10.1128/microbiolspec.mdna3-0037-2014] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The primary antibody repertoire is generated by mechanisms involving the assembly of the exons that encode the antigen-binding variable regions of immunoglobulin heavy (IgH) and light (IgL) chains during the early development of B lymphocytes. After antigen-dependent activation, mature B lymphocytes can further alter their IgH and IgL variable region exons by the process of somatic hypermutation (SHM), which allows the selection of B cells in which SHMs resulted in the production of antibodies with increased antigen affinity. In addition, during antigen-dependent activation, B cells can also change the constant region of their IgH chain through a DNA double-strand-break (DSB) dependent process referred to as IgH class switch recombination (CSR), which generates B cell progeny that produce antibodies with different IgH constant region effector functions that are best suited for a elimination of a particular pathogen or in a particular setting. Both the mutations that underlie SHM and the DSBs that underlie CSR are initiated in target genes by activation-induced cytidine deaminase (AID). This review describes in depth the processes of SHM and CSR with a focus on mechanisms that direct AID cytidine deamination in activated B cells and mechanisms that promote the differential outcomes of such cytidine deamination.
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37
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Bregenhorn S, Kallenberger L, Artola-Borán M, Peña-Diaz J, Jiricny J. Non-canonical uracil processing in DNA gives rise to double-strand breaks and deletions: relevance to class switch recombination. Nucleic Acids Res 2016; 44:2691-705. [PMID: 26743004 PMCID: PMC4824095 DOI: 10.1093/nar/gkv1535] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 12/23/2015] [Indexed: 12/24/2022] Open
Abstract
During class switch recombination (CSR), antigen-stimulated B-cells rearrange their immunoglobulin constant heavy chain (CH) loci to generate antibodies with different effector functions. CSR is initiated by activation-induced deaminase (AID), which converts cytosines in switch (S) regions, repetitive sequences flanking the CH loci, to uracils. Although U/G mispairs arising in this way are generally efficiently repaired to C/Gs by uracil DNA glycosylase (UNG)-initiated base excision repair (BER), uracil processing in S-regions of activated B-cells occasionally gives rise to double strand breaks (DSBs), which trigger CSR. Surprisingly, genetic experiments revealed that CSR is dependent not only on AID and UNG, but also on mismatch repair (MMR). To elucidate the role of MMR in CSR, we studied the processing of uracil-containing DNA substrates in extracts of MMR-proficient and –deficient human cells, as well as in a system reconstituted from recombinant BER and MMR proteins. Here, we show that the interplay of these repair systems gives rise to DSBs in vitro and to genomic deletions and mutations in vivo, particularly in an S-region sequence. Our findings further suggest that MMR affects pathway choice in DSB repair. Given its amenability to manipulation, our system represents a powerful tool for the molecular dissection of CSR.
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Affiliation(s)
- Stephanie Bregenhorn
- Institute of Molecular Cancer Research, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland Department of Biology, Swiss Federal Institute of Technology (ETH) Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Lia Kallenberger
- Institute of Molecular Cancer Research, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Mariela Artola-Borán
- Institute of Molecular Cancer Research, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Javier Peña-Diaz
- Institute of Molecular Cancer Research, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland University of Copenhagen, Faculty of Health Sciences Center for Healthy Aging, Department of Neuroscience and Pharmacology, Blegdamsvej 3b, DK-2200 Copenhagen N, Denmark
| | - Josef Jiricny
- Institute of Molecular Cancer Research, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland Department of Biology, Swiss Federal Institute of Technology (ETH) Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
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38
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Srour N, Chemin G, Tinguely A, Ashi MO, Oruc Z, Péron S, Sirac C, Cogné M, Delpy L. A plasma cell differentiation quality control ablates B cell clones with biallelic Ig rearrangements and truncated Ig production. J Exp Med 2015; 213:109-22. [PMID: 26666261 PMCID: PMC4710196 DOI: 10.1084/jem.20131511] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 11/12/2015] [Indexed: 01/26/2023] Open
Abstract
Aberrantly rearranged immunoglobulin (Ig) alleles are frequent. They are usually considered sterile and innocuous as a result of nonsense-mediated mRNA decay. However, alternative splicing can yield internally deleted proteins from such nonproductively V(D)J-rearranged loci. We show that nonsense codons from variable (V) Igκ exons promote exon-skipping and synthesis of V domain-less κ light chains (ΔV-κLCs). Unexpectedly, such ΔV-κLCs inhibit plasma cell (PC) differentiation. Accordingly, in wild-type mice, rearrangements encoding ΔV-κLCs are rare in PCs, but frequent in B cells. Likewise, enforcing expression of ΔV-κLCs impaired PC differentiation and antibody responses without disturbing germinal center reactions. In addition, PCs expressing ΔV-κLCs synthesize low levels of Ig and are mostly found among short-lived plasmablasts. ΔV-κLCs have intrinsic toxic effects in PCs unrelated to Ig assembly, but mediated by ER stress-associated apoptosis, making PCs producing ΔV-κLCs highly sensitive to proteasome inhibitors. Altogether, these findings demonstrate a quality control checkpoint blunting terminal PC differentiation by eliminating those cells expressing nonfunctionally rearranged Igκ alleles. This truncated Ig exclusion (TIE) checkpoint ablates PC clones with ΔV-κLCs production and exacerbated ER stress response. The TIE checkpoint thus mediates selection of long-lived PCs with limited ER stress supporting high Ig secretion, but with a cost in terms of antigen-independent narrowing of the repertoire.
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Affiliation(s)
- Nivine Srour
- Centre National de la Recherche Scientifique UMR 7276, Université de Limoges, 87000 Limoges, France
| | - Guillaume Chemin
- Centre National de la Recherche Scientifique UMR 7276, Université de Limoges, 87000 Limoges, France
| | - Aurélien Tinguely
- Centre National de la Recherche Scientifique UMR 7276, Université de Limoges, 87000 Limoges, France
| | - Mohamad Omar Ashi
- Centre National de la Recherche Scientifique UMR 7276, Université de Limoges, 87000 Limoges, France
| | - Zéliha Oruc
- Centre National de la Recherche Scientifique UMR 7276, Université de Limoges, 87000 Limoges, France
| | - Sophie Péron
- Centre National de la Recherche Scientifique UMR 7276, Université de Limoges, 87000 Limoges, France
| | - Christophe Sirac
- Centre National de la Recherche Scientifique UMR 7276, Université de Limoges, 87000 Limoges, France
| | - Michel Cogné
- Centre National de la Recherche Scientifique UMR 7276, Université de Limoges, 87000 Limoges, France Institut Universitaire de France, Université de Limoges, 87000 Limoges, France
| | - Laurent Delpy
- Centre National de la Recherche Scientifique UMR 7276, Université de Limoges, 87000 Limoges, France
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The FOXO1 Transcription Factor Instructs the Germinal Center Dark Zone Program. Immunity 2015; 43:1064-74. [PMID: 26620759 DOI: 10.1016/j.immuni.2015.10.015] [Citation(s) in RCA: 194] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 08/30/2015] [Accepted: 10/22/2015] [Indexed: 12/18/2022]
Abstract
The pathways regulating formation of the germinal center (GC) dark zone (DZ) and light zone (LZ) are unknown. In this study we show that FOXO1 transcription factor expression was restricted to the GC DZ and was required for DZ formation, since its absence in mice led to the loss of DZ gene programs and the formation of LZ-only GCs. FOXO1-negative GC B cells displayed normal somatic hypermutation but defective affinity maturation and class switch recombination. The function of FOXO1 in sustaining the DZ program involved the trans-activation of the chemokine receptor CXCR4, and cooperation with the BCL6 transcription factor in the trans-repression of genes involved in immune activation, DNA repair, and plasma cell differentiation. These results also have implications for the role of FOXO1 in lymphomagenesis because they suggest that constitutive FOXO1 activity might be required for the oncogenic activity of deregulated BCL6 expression.
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40
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Chen Z, Getahun A, Chen X, Dollin Y, Cambier JC, Wang JH. Imbalanced PTEN and PI3K Signaling Impairs Class Switch Recombination. THE JOURNAL OF IMMUNOLOGY 2015; 195:5461-5471. [PMID: 26500350 DOI: 10.4049/jimmunol.1501375] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 09/24/2015] [Indexed: 02/05/2023]
Abstract
Class switch recombination (CSR) generates isotype-switched Abs with distinct effector functions. B cells express phosphatase and tensin homolog (PTEN) and multiple isoforms of class IA PI3K catalytic subunits, including p110α and p110δ, whose roles in CSR remain unknown or controversial. In this article, we demonstrate a direct effect of PTEN on CSR signaling by acute deletion of Pten specifically in mature B cells, thereby excluding the developmental impact of Pten deletion. We show that mature B cell-specific PTEN overexpression enhances CSR. More importantly, we establish a critical role for p110α in CSR. Furthermore, we identify a cooperative role for p110α and p110δ in suppressing CSR. Mechanistically, dysregulation of p110α or PTEN inversely affects activation-induced deaminase expression via modulating AKT activity. Thus, our study reveals that a signaling balance between PTEN and PI3K isoforms is essential to maintain normal CSR.
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Affiliation(s)
- Zhangguo Chen
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, School of Medicine, Aurora, CO 80045.,Department of Biomedical Research, National Jewish Health, Denver, CO 80206
| | - Andrew Getahun
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, School of Medicine, Aurora, CO 80045.,Department of Biomedical Research, National Jewish Health, Denver, CO 80206
| | - Xiaomi Chen
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, School of Medicine, Aurora, CO 80045
| | - Yonatan Dollin
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, School of Medicine, Aurora, CO 80045
| | - John C Cambier
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, School of Medicine, Aurora, CO 80045.,Department of Biomedical Research, National Jewish Health, Denver, CO 80206
| | - Jing H Wang
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, School of Medicine, Aurora, CO 80045.,Department of Biomedical Research, National Jewish Health, Denver, CO 80206
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41
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Complexity of the human memory B-cell compartment is determined by the versatility of clonal diversification in germinal centers. Proc Natl Acad Sci U S A 2015; 112:E5281-9. [PMID: 26324941 DOI: 10.1073/pnas.1511270112] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Our knowledge about the clonal composition and intraclonal diversity of the human memory B-cell compartment and the relationship between memory B-cell subsets is still limited, although these are central issues for our understanding of adaptive immunity. We performed a deep sequencing analysis of rearranged immunoglobulin (Ig) heavy chain genes from biological replicates, covering more than 100,000 memory B lymphocytes from two healthy adults. We reveal a highly similar B-cell receptor repertoire among the four main human IgM(+) and IgG(+) memory B-cell subsets. Strikingly, in both donors, 45% of sequences could be assigned to expanded clones, demonstrating that the human memory B-cell compartment is characterized by many, often very large, B-cell clones. Twenty percent of the clones consisted of class switched and IgM(+)(IgD(+)) members, a feature that correlated significantly with clone size. Hence, we provide strong evidence that the vast majority of Ig mutated B cells--including IgM(+)IgD(+)CD27(+) B cells--are post-germinal center (GC) memory B cells. Clone members showed high intraclonal sequence diversity and high intraclonal versatility in Ig class and IgG subclass composition, with particular patterns of memory B-cell clone generation in GC reactions. In conclusion, GC produce amazingly large, complex, and diverse memory B-cell clones, equipping the human immune system with a versatile and highly diverse compartment of IgM(+)(IgD(+)) and class-switched memory B cells.
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42
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Khair L, Baker RE, Linehan EK, Schrader CE, Stavnezer J. Nbs1 ChIP-Seq Identifies Off-Target DNA Double-Strand Breaks Induced by AID in Activated Splenic B Cells. PLoS Genet 2015; 11:e1005438. [PMID: 26263206 PMCID: PMC4532491 DOI: 10.1371/journal.pgen.1005438] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 07/10/2015] [Indexed: 01/03/2023] Open
Abstract
Activation-induced cytidine deaminase (AID) is required for initiation of Ig class switch recombination (CSR) and somatic hypermutation (SHM) of antibody genes during immune responses. AID has also been shown to induce chromosomal translocations, mutations, and DNA double-strand breaks (DSBs) involving non-Ig genes in activated B cells. To determine what makes a DNA site a target for AID-induced DSBs, we identify off-target DSBs induced by AID by performing chromatin immunoprecipitation (ChIP) for Nbs1, a protein that binds DSBs, followed by deep sequencing (ChIP-Seq). We detect and characterize hundreds of off-target AID-dependent DSBs. Two types of tandem repeats are highly enriched within the Nbs1-binding sites: long CA repeats, which can form Z-DNA, and tandem pentamers containing the AID target hotspot WGCW. These tandem repeats are not nearly as enriched at AID-independent DSBs, which we also identified. Msh2, a component of the mismatch repair pathway and important for genome stability, increases off-target DSBs, similar to its effect on Ig switch region DSBs, which are required intermediates during CSR. Most of the off-target DSBs are two-ended, consistent with generation during G1 phase, similar to DSBs in Ig switch regions. However, a minority are one-ended, presumably due to conversion of single-strand breaks to DSBs during replication. One-ended DSBs are repaired by processes involving homologous recombination, including break-induced replication repair, which can lead to genome instability. Off-target DSBs, especially those present during S phase, can lead to chromosomal translocations, deletions and gene amplifications, resulting in the high frequency of B cell lymphomas derived from cells that express or have expressed AID. Activation-induced cytidine deaminase (AID) is required for diversifying antibodies during immune responses, and it does this by introducing mutations and DNA breaks into antibody genes. How AID is targeted is not understood, and it induces chromosomal translocations, mutations, and double-strand breaks (DSBs) at sites other than antibody genes in activated B cells. To determine what makes an off-target DNA site a target for AID-induced DSBs, we identify and characterize hundreds of genome-wide DSBs induced by AID during B cell activation. Interestingly, many of the DSBs are within or adjacent to two types of tandemly repeated simple sequences, which have characteristics that might explain why they are targeted. We find that most of the DSBs are two-ended, consistent with their generation during G1 phase of the cell cycle, which is when AID induces DNA breaks in antibody genes. However, a minority is one-ended, consistent with replication encountering an AID-induced single-strand break, thereby creating a DSB. Both types of off-target DSBs, but especially those present during S phase of the cell cycle, lead to chromosomal translocations, deletions and gene amplifications that can promote B cell lymphomagenesis.
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Affiliation(s)
- Lyne Khair
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Richard E. Baker
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Erin K. Linehan
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Carol E. Schrader
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Janet Stavnezer
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- * E-mail:
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43
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Bonaud A, Lechouane F, Le Noir S, Monestier O, Cogné M, Sirac C. Efficient AID targeting of switch regions is not sufficient for optimal class switch recombination. Nat Commun 2015; 6:7613. [PMID: 26146363 DOI: 10.1038/ncomms8613] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 05/26/2015] [Indexed: 02/07/2023] Open
Abstract
Antibody affinity maturation relies on activation-induced cytidine deaminase (AID)-dependent somatic hypermutation (SHM) of immunoglobulin (Ig) loci. Class switch recombination (CSR) can in parallel occur between AID-targeted, transcribed, spliced and repetitive switch (S) regions. AID thus initiates not only mutations but also double-strand breaks (DSBs). What governs the choice between those two outcomes remains uncertain. Here we explore whether insertion of transcribed intronic S regions in a locus (Igκ) strongly recruiting AID is sufficient for efficient CSR. Although strongly targeted by AID and carrying internal deletions, the knocked-in S regions only undergo rare CSR-like events. This model confirms S regions as exquisite SHM targets, extending AID activity far from transcription initiation sites, and shows that such spliced and repetitive AID targets are not sufficient by themselves for CSR. Beyond transcription and AID recruitment, additional IgH elements are thus needed for CSR, restricting this hazardous gene remodelling to IgH loci.
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Affiliation(s)
- Amélie Bonaud
- Immunology, CNRS UMR 7276, Centre Nationale de la Recherche Scientifique, Université de Limoges, Limoges 87025, France
| | - Fabien Lechouane
- Immunology, CNRS UMR 7276, Centre Nationale de la Recherche Scientifique, Université de Limoges, Limoges 87025, France
| | - Sandrine Le Noir
- Immunology, CNRS UMR 7276, Centre Nationale de la Recherche Scientifique, Université de Limoges, Limoges 87025, France
| | - Olivier Monestier
- Immunology, CNRS UMR 7276, Centre Nationale de la Recherche Scientifique, Université de Limoges, Limoges 87025, France
| | - Michel Cogné
- 1] Immunology, CNRS UMR 7276, Centre Nationale de la Recherche Scientifique, Université de Limoges, Limoges 87025, France. [2] Institut Universitaire de France, Paris 75000, France
| | - Christophe Sirac
- Immunology, CNRS UMR 7276, Centre Nationale de la Recherche Scientifique, Université de Limoges, Limoges 87025, France
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44
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Batoulis H, Wunsch M, Birkenheier J, Rottlaender A, Gorboulev V, Kuerten S. Central nervous system infiltrates are characterized by features of ongoing B cell-related immune activity in MP4-induced experimental autoimmune encephalomyelitis. Clin Immunol 2015; 158:47-58. [PMID: 25796192 DOI: 10.1016/j.clim.2015.03.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2014] [Revised: 03/11/2015] [Accepted: 03/12/2015] [Indexed: 12/25/2022]
Abstract
In multiple sclerosis (MS) lymphoid follicle-like aggregates have been reported in the meninges of patients. Here we investigated the functional relevance of B cell infiltration into the central nervous system (CNS) in MP4-induced experimental autoimmune encephalomyelitis (EAE), a B cell-dependent mouse model of MS. In chronic EAE, B cell aggregates were characterized by the presence of CXCL13(+) and germinal center CD10(+) B cells. Germline transcripts were expressed in the CNS and particularly related to TH17-associated isotypes. We also observed B cells with restricted VH gene usage that differed from clones found in the spleen. Finally, we detected CNS-restricted spreading of the antigen-specific B cell response towards a myelin and a neuronal autoantigen. These data imply the development of autonomous B cell-mediated autoimmunity in the CNS in EAE - a concept that might also apply to MS itself.
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Affiliation(s)
- Helena Batoulis
- Department of Anatomy I, University of Cologne, Joseph-Stelzmann-Str. 9, 50931 Cologne, Germany
| | - Marie Wunsch
- Department of Anatomy and Cell Biology, University of Wuerzburg, Koellikerstr. 6, 97070 Wuerzburg, Germany
| | - Johannes Birkenheier
- Department of Anatomy I, University of Cologne, Joseph-Stelzmann-Str. 9, 50931 Cologne, Germany
| | - Andrea Rottlaender
- Department of Anatomy and Cell Biology, University of Wuerzburg, Koellikerstr. 6, 97070 Wuerzburg, Germany
| | - Valentin Gorboulev
- Department of Anatomy and Cell Biology, University of Wuerzburg, Koellikerstr. 6, 97070 Wuerzburg, Germany
| | - Stefanie Kuerten
- Department of Anatomy and Cell Biology, University of Wuerzburg, Koellikerstr. 6, 97070 Wuerzburg, Germany.
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45
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Savage P. Clinical observations on chemotherapy curable malignancies: unique genetic events, frozen development and enduring apoptotic potential. BMC Cancer 2015; 15:11. [PMID: 25605631 PMCID: PMC4308945 DOI: 10.1186/s12885-015-1006-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 12/31/2014] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND A select number of relatively rare metastatic malignancies comprising trophoblast tumours, the rare childhood cancers, germ cells tumours, leukemias and lymphomas have been routinely curable with chemotherapy for more than 30 years. However for the more common metastatic malignancies chemotherapy treatment frequently brings clinical benefits but cure is not expected. Clinically this clear divide in outcome between the tumour types can appear at odds with the classical theories of chemotherapy sensitivity and resistance that include rates of proliferation, genetic development of drug resistance and drug efflux pumps. We have looked at the clinical characteristics of the chemotherapy curable malignancies to see if they have any common factors that could explain this extreme differential sensitivity to chemotherapy. DISCUSSION It has previously been noted how the onset of malignancy can leave malignant cells fixed with some key cellular functions remaining frozen at the point in development at which malignant transformation occurred. In the chemotherapy curable malignancies the onset of malignancy is in each case closely linked to one of the unique genetic events of; nuclear fusion for molar pregnancies, choriocarcinoma and placental site trophoblast tumours, gastrulation for the childhood cancers, meiosis for testicular cancer and ovarian germ cell tumours and VDJ rearrangement and somatic hypermutation for acute leukemia and lymphoma. These processes are all linked to natural periods of supra-physiological apoptotic potential and it appears that the malignant cells arising from them usually retain this heightened sensitivity to DNA damage. To investigate this hypothesis we have examined the natural history of the healthy cells during these processes and the chemotherapy sensitivity of malignancies arising before, during and after the events. To add to the debate on chemotherapy resistance and sensitivity, we would argue that malignancies can be functionally divided into 2 groups. Firstly those that arise in cells with naturally heightened apoptotic potential as a result of their proximity to the unique genetic events, where the malignancies are generally chemotherapy curable and then the more common malignancies that arise in cells of standard apoptotic potential that are not curable with classical cytotoxic drugs.
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Affiliation(s)
- Philip Savage
- BCCA Vancouver Island, 2410 Lee Avenue, Victoria, BC, V8R 6V5, Canada.
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46
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Sasaki Y, Iwai K. Roles of the NF-κB Pathway in B-Lymphocyte Biology. Curr Top Microbiol Immunol 2015; 393:177-209. [PMID: 26275874 DOI: 10.1007/82_2015_479] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
NF-κB was originally identified as a family of transcription factors that bind the enhancer of the immunoglobulin κ light-chain gene. Although its function in the regulation of immunoglobulin κ light-chain gene remains unclear, NF-κB plays critical roles in development, survival, and activation of B lymphocytes. In B cells, many receptors, including B-cell antigen receptor (BCR), activate NF-κB pathway, and the molecular mechanism of receptor-mediated activation of IκB kinase (IKK) complex has been partially revealed. In addition to normal B lymphocytes, NF-κB is also involved in the growth of some types of B-cell lymphomas, and many oncogenic mutations involved in constitutive activation of the NF-κB pathway were recently identified in such cancers. In this review, we first summarize the function of NF-κB in B-cell development and activation, and then describe recent progress in understanding the molecular mechanism of receptor-mediated activation of the IKK complex, focusing on the roles of the ubiquitin system. In the last section, we describe oncogenic mutations that induce NF-κB activation in B-cell lymphoma.
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Affiliation(s)
- Yoshiteru Sasaki
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Kyoto University, Kyoto, 606-8501, Japan.
| | - Kazuhiro Iwai
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Kyoto University, Kyoto, 606-8501, Japan
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Chen Z, Ranganath S, Viboolsittiseri SS, Eder MD, Chen X, Elos MT, Yuan S, Yuan S, Hansen E, Wang JH. AID-initiated DNA lesions are differentially processed in distinct B cell populations. THE JOURNAL OF IMMUNOLOGY 2014; 193:5545-56. [PMID: 25339658 DOI: 10.4049/jimmunol.1401549] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Activation-induced deaminase (AID) initiates U:G mismatches, causing point mutations or DNA double-stranded breaks at Ig loci. How AID-initiated lesions are prevented from inducing genome-wide damage remains elusive. A differential DNA repair mechanism might protect certain non-Ig loci such as c-myc from AID attack. However, determinants regulating such protective mechanisms are largely unknown. To test whether target DNA sequences modulate protective mechanisms via altering the processing manner of AID-initiated lesions, we established a knock-in model by inserting an Sγ2b region, a bona fide AID target, into the first intron of c-myc. Unexpectedly, we found that the inserted S region did not mutate or enhance c-myc genomic instability, due to error-free repair of AID-initiated lesions, in Ag-stimulated germinal center B cells. In contrast, in vitro cytokine-activated B cells display a much higher level of c-myc genomic instability in an AID- and S region-dependent manner. Furthermore, we observe a comparable frequency of AID deamination events between the c-myc intronic sequence and inserted S region in different B cell populations, demonstrating a similar frequency of AID targeting. Thus, our study reveals a clear difference between germinal center and cytokine-activated B cells in their ability to develop genomic instability, attributable to a differential processing of AID-initiated lesions in distinct B cell populations. We propose that locus-specific regulatory mechanisms (e.g., transcription) appear to not only override the effects of S region sequence on AID targeting frequency but also influence the repair manner of AID-initiated lesions.
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Affiliation(s)
- Zhangguo Chen
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045; Department of Biomedical Research, National Jewish Health, Denver, CO 80206; and
| | - Sheila Ranganath
- Boston Children's Hospital, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115
| | - Sawanee S Viboolsittiseri
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045
| | - Maxwell D Eder
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045
| | - Xiaomi Chen
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045; Department of Biomedical Research, National Jewish Health, Denver, CO 80206; and
| | - Mihret T Elos
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045
| | - Shunzong Yuan
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045
| | | | - Erica Hansen
- Boston Children's Hospital, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115
| | - Jing H Wang
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045; Department of Biomedical Research, National Jewish Health, Denver, CO 80206; and
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Shih HY, Sciumè G, Poholek AC, Vahedi G, Hirahara K, Villarino AV, Bonelli M, Bosselut R, Kanno Y, Muljo SA, O'Shea JJ. Transcriptional and epigenetic networks of helper T and innate lymphoid cells. Immunol Rev 2014; 261:23-49. [PMID: 25123275 PMCID: PMC4321863 DOI: 10.1111/imr.12208] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The discovery of the specification of CD4(+) helper T cells to discrete effector 'lineages' represented a watershed event in conceptualizing mechanisms of host defense and immunoregulation. However, our appreciation for the actual complexity of helper T-cell subsets continues unabated. Just as the Sami language of Scandinavia has 1000 different words for reindeer, immunologists recognize the range of fates available for a CD4(+) T cell is numerous and may be underestimated. Added to the crowded scene for helper T-cell subsets is the continuously growing family of innate lymphoid cells (ILCs), endowed with common effector responses and the previously defined 'master regulators' for CD4(+) helper T-cell subsets are also shared by ILC subsets. Within the context of this extraordinary complexity are concomitant advances in the understanding of transcriptomes and epigenomes. So what do terms like 'lineage commitment' and helper T-cell 'specification' mean in the early 21st century? How do we put all of this together in a coherent conceptual framework? It would be arrogant to assume that we have a sophisticated enough understanding to seriously answer these questions. Instead, we review the current status of the flexibility of helper T-cell responses in relation to their genetic regulatory networks and epigenetic landscapes. Recent data have provided major surprises as to what master regulators can or cannot do, how they interact with other transcription factors and impact global genome-wide changes, and how all these factors come together to influence helper cell function.
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Affiliation(s)
- Han-Yu Shih
- Molecular Immunology and Inflammation Branch, National Institute of Arthritis, and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
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Hamperl S, Cimprich KA. The contribution of co-transcriptional RNA:DNA hybrid structures to DNA damage and genome instability. DNA Repair (Amst) 2014; 19:84-94. [PMID: 24746923 PMCID: PMC4051866 DOI: 10.1016/j.dnarep.2014.03.023] [Citation(s) in RCA: 202] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Accurate DNA replication and DNA repair are crucial for the maintenance of genome stability, and it is generally accepted that failure of these processes is a major source of DNA damage in cells. Intriguingly, recent evidence suggests that DNA damage is more likely to occur at genomic loci with high transcriptional activity. Furthermore, loss of certain RNA processing factors in eukaryotic cells is associated with increased formation of co-transcriptional RNA:DNA hybrid structures known as R-loops, resulting in double-strand breaks (DSBs) and DNA damage. However, the molecular mechanisms by which R-loop structures ultimately lead to DNA breaks and genome instability is not well understood. In this review, we summarize the current knowledge about the formation, recognition and processing of RNA:DNA hybrids, and discuss possible mechanisms by which these structures contribute to DNA damage and genome instability in the cell.
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Affiliation(s)
- Stephan Hamperl
- Department of Chemical, Systems Biology, Stanford University School of Medicine, 318 Campus Drive, Stanford, CA 94305-5441, USA
| | - Karlene A Cimprich
- Department of Chemical, Systems Biology, Stanford University School of Medicine, 318 Campus Drive, Stanford, CA 94305-5441, USA.
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Miyashita A, Kizaki H, Kawasaki K, Sekimizu K, Kaito C. Primed immune responses to gram-negative peptidoglycans confer infection resistance in silkworms. J Biol Chem 2014; 289:14412-21. [PMID: 24706746 DOI: 10.1074/jbc.m113.525139] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
A heightened immune response, in which immune responses are primed by repeated exposure to a pathogen, is an important characteristic of vertebrate adaptive immunity. In the present study, we examined whether invertebrate animals also exhibit a primed immune response. The LD50 of Gram-negative enterohemorrhagic Escherichia coli O157:H7 Sakai in silkworms was increased 100-fold by pre-injection of heat-killed Sakai cells. Silkworms pre-injected with heat-killed cells of a Gram-positive bacterium, Staphylococcus aureus, did not have resistance to Sakai. Silkworms preinjected with enterohemorrhagic E. coli peptidoglycans, cell surface components of bacteria, were resistant to Sakai infection. Silkworms preinjected with S. aureus peptidoglycans, however, were not resistant to Sakai. Silkworms preinjected with heat-killed Sakai cells showed persistent resistance to Sakai infection even after pupation. Repeated injection of heat-killed Sakai cells into the silkworms induced earlier and greater production of antimicrobial peptides than a single injection of heat-killed Sakai cells. These findings suggest that silkworm recognition of Gram-negative peptidoglycans leads to a primed immune reaction and increased resistance to a second round of bacterial infection.
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Affiliation(s)
- Atsushi Miyashita
- From the Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 3-1, 7-chome, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hayato Kizaki
- From the Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 3-1, 7-chome, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Kiyoshi Kawasaki
- the Laboratory of Microbiology, Faculty of Pharmaceutical Sciences, Doshisha Women's College, Kyotanabe 610-0395, Japan
| | - Kazuhisa Sekimizu
- From the Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 3-1, 7-chome, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Chikara Kaito
- From the Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 3-1, 7-chome, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan,
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