1
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Fawzy MM, Nazmy MH, El-Sheikh AAK, Fathy M. Evolutionary preservation of CpG dinucleotides in RAG1 may elucidate the relatively high rate of methylation-mediated mutagenesis of RAG1 transposase. Immunol Res 2024; 72:438-449. [PMID: 38240953 PMCID: PMC11217092 DOI: 10.1007/s12026-023-09451-8] [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: 08/10/2023] [Accepted: 12/24/2023] [Indexed: 07/03/2024]
Abstract
Recombination-activating gene 1 (RAG1) is a vital player in V(D)J recombination, a fundamental process in primary B cell and T cell receptor diversification of the adaptive immune system. Current vertebrate RAG evolved from RAG transposon; however, it has been modified to play a crucial role in the adaptive system instead of being irreversibly silenced by CpG methylation. By interrogating a range of publicly available datasets, the current study investigated whether RAG1 has retained a disproportionate level of its original CpG dinucleotides compared to other genes, thereby rendering it more exposed to methylation-mediated mutation. Here, we show that 57.57% of RAG1 pathogenic mutations and 51.6% of RAG1 disease-causing mutations were associated with CpG methylation, a percentage that was significantly higher than that of its RAG2 cofactor alongside the whole genome. The CpG scores and densities for all RAG ancestors suggested that RAG transposon was CpG denser. The percentage of the ancestral CpG of RAG1 and RAG2 were 6% and 4.2%, respectively, with no preference towards CG containing codons. Furthermore, CpG loci of RAG1 in sperms were significantly higher methylated than that of RAG2. In conclusion, RAG1 has been exposed to CpG mediated methylation mutagenesis more than RAG2 and the whole genome, presumably due to its late entry to the genome later with an initially higher CpG content.
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Affiliation(s)
- Mariam M Fawzy
- Department of Biochemistry, Faculty of Pharmacy, Minia University, Minia, 61519, Egypt
| | - Maiiada H Nazmy
- Department of Biochemistry, Faculty of Pharmacy, Minia University, Minia, 61519, Egypt
| | - Azza A K El-Sheikh
- Basic Health Sciences Department, College of Medicine, Princess Nourah bint Abdulrahman University, 11671, Riyadh, Saudi Arabia
| | - Moustafa Fathy
- Department of Biochemistry, Faculty of Pharmacy, Minia University, Minia, 61519, Egypt.
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2
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Chen R, Lukianova E, van der Loeff IS, Spegarova JS, Willet JDP, James KD, Ryder EJ, Griffin H, IJspeert H, Gajbhiye A, Lamoliatte F, Marin-Rubio JL, Woodbine L, Lemos H, Swan DJ, Pintar V, Sayes K, Ruiz-Morales ER, Eastham S, Dixon D, Prete M, Prigmore E, Jeggo P, Boyes J, Mellor A, Huang L, van der Burg M, Engelhardt KR, Stray-Pedersen A, Erichsen HC, Gennery AR, Trost M, Adams DJ, Anderson G, Lorenc A, Trynka G, Hambleton S. NUDCD3 deficiency disrupts V(D)J recombination to cause SCID and Omenn syndrome. Sci Immunol 2024; 9:eade5705. [PMID: 38787962 DOI: 10.1126/sciimmunol.ade5705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 04/24/2024] [Indexed: 05/26/2024]
Abstract
Inborn errors of T cell development present a pediatric emergency in which timely curative therapy is informed by molecular diagnosis. In 11 affected patients across four consanguineous kindreds, we detected homozygosity for a single deleterious missense variant in the gene NudC domain-containing 3 (NUDCD3). Two infants had severe combined immunodeficiency with the complete absence of T and B cells (T -B- SCID), whereas nine showed classical features of Omenn syndrome (OS). Restricted antigen receptor gene usage by residual T lymphocytes suggested impaired V(D)J recombination. Patient cells showed reduced expression of NUDCD3 protein and diminished ability to support RAG-mediated recombination in vitro, which was associated with pathologic sequestration of RAG1 in the nucleoli. Although impaired V(D)J recombination in a mouse model bearing the homologous variant led to milder immunologic abnormalities, NUDCD3 is absolutely required for healthy T and B cell development in humans.
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Affiliation(s)
- Rui Chen
- Translational and Clinical Research Institute, Newcastle University, NE2 4HH Newcastle upon Tyne, UK
| | - Elena Lukianova
- Wellcome Sanger Institute, Wellcome Genome Campus, CB10 1SA Hinxton, UK
| | - Ina Schim van der Loeff
- Translational and Clinical Research Institute, Newcastle University, NE2 4HH Newcastle upon Tyne, UK
- Great North Children's Hospital, Newcastle upon Tyne Hospitals NHS Foundation Trust, NE1 4LP Newcastle upon Tyne, UK
| | | | - Joseph D P Willet
- Translational and Clinical Research Institute, Newcastle University, NE2 4HH Newcastle upon Tyne, UK
| | - Kieran D James
- Institute of Immunology and Immunotherapy, University of Birmingham. B15 2TT Birmingham, UK
| | - Edward J Ryder
- Wellcome Sanger Institute, Wellcome Genome Campus, CB10 1SA Hinxton, UK
| | - Helen Griffin
- Translational and Clinical Research Institute, Newcastle University, NE2 4HH Newcastle upon Tyne, UK
| | - Hanna IJspeert
- Department of Immunology, Erasmus University Medical Center, Rotterdam 3000 CA, Netherlands
| | - Akshada Gajbhiye
- Biosciences Institute, Newcastle University, NE2 4HH Newcastle upon Tyne, UK
| | - Frederic Lamoliatte
- Biosciences Institute, Newcastle University, NE2 4HH Newcastle upon Tyne, UK
| | - Jose L Marin-Rubio
- Biosciences Institute, Newcastle University, NE2 4HH Newcastle upon Tyne, UK
| | - Lisa Woodbine
- Genome Damage and Stability Centre, University of Sussex, BN1 9RQ Brighton, UK
| | - Henrique Lemos
- Translational and Clinical Research Institute, Newcastle University, NE2 4HH Newcastle upon Tyne, UK
| | - David J Swan
- Translational and Clinical Research Institute, Newcastle University, NE2 4HH Newcastle upon Tyne, UK
| | - Valeria Pintar
- Translational and Clinical Research Institute, Newcastle University, NE2 4HH Newcastle upon Tyne, UK
| | - Kamal Sayes
- Translational and Clinical Research Institute, Newcastle University, NE2 4HH Newcastle upon Tyne, UK
| | | | - Simon Eastham
- Wellcome Sanger Institute, Wellcome Genome Campus, CB10 1SA Hinxton, UK
| | - David Dixon
- Biosciences Institute, Newcastle University, NE2 4HH Newcastle upon Tyne, UK
| | - Martin Prete
- Wellcome Sanger Institute, Wellcome Genome Campus, CB10 1SA Hinxton, UK
| | - Elena Prigmore
- Wellcome Sanger Institute, Wellcome Genome Campus, CB10 1SA Hinxton, UK
| | - Penny Jeggo
- Genome Damage and Stability Centre, University of Sussex, BN1 9RQ Brighton, UK
| | - Joan Boyes
- Faculty of Biological Sciences, University of Leeds, LS2 9JT Leeds, UK
| | - Andrew Mellor
- Translational and Clinical Research Institute, Newcastle University, NE2 4HH Newcastle upon Tyne, UK
| | - Lei Huang
- Translational and Clinical Research Institute, Newcastle University, NE2 4HH Newcastle upon Tyne, UK
| | - Mirjam van der Burg
- Department of Immunology, Erasmus University Medical Center, Rotterdam 3000 CA, Netherlands
| | - Karin R Engelhardt
- Translational and Clinical Research Institute, Newcastle University, NE2 4HH Newcastle upon Tyne, UK
| | - Asbjørg Stray-Pedersen
- Norwegian National Unit for Newborn Screening, Division of Pediatric and Adolescent Medicine, Oslo University Hospital, Oslo 0424, Norway
| | - Hans Christian Erichsen
- Division of Pediatric and Adolescent Medicine, Oslo University Hospital and Institute of Clinical Medicine, University of Oslo, Oslo 0424, Norway
| | - Andrew R Gennery
- Translational and Clinical Research Institute, Newcastle University, NE2 4HH Newcastle upon Tyne, UK
- Great North Children's Hospital, Newcastle upon Tyne Hospitals NHS Foundation Trust, NE1 4LP Newcastle upon Tyne, UK
| | - Matthias Trost
- Biosciences Institute, Newcastle University, NE2 4HH Newcastle upon Tyne, UK
| | - David J Adams
- Wellcome Sanger Institute, Wellcome Genome Campus, CB10 1SA Hinxton, UK
| | - Graham Anderson
- Institute of Immunology and Immunotherapy, University of Birmingham. B15 2TT Birmingham, UK
| | - Anna Lorenc
- Wellcome Sanger Institute, Wellcome Genome Campus, CB10 1SA Hinxton, UK
| | - Gosia Trynka
- Wellcome Sanger Institute, Wellcome Genome Campus, CB10 1SA Hinxton, UK
- Open Targets, Wellcome Genome Campus, CB10 1SA Hinxton, UK
| | - Sophie Hambleton
- Translational and Clinical Research Institute, Newcastle University, NE2 4HH Newcastle upon Tyne, UK
- Great North Children's Hospital, Newcastle upon Tyne Hospitals NHS Foundation Trust, NE1 4LP Newcastle upon Tyne, UK
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3
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Zhang R, Wang D, Ruan GX, Wang R, Li Y, Chen W, Huang H, Wang J, Meng L, Zhu Z, Lei D, Xu S, Ou X. Spliceosome component PHD finger 5A is essential for early B lymphopoiesis. Development 2024; 151:dev202247. [PMID: 38095286 DOI: 10.1242/dev.202247] [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: 08/08/2023] [Accepted: 12/08/2023] [Indexed: 01/12/2024]
Abstract
The spliceosome, a multi-megadalton ribonucleoprotein complex, is essential for pre-mRNA splicing in the nucleus and ensuring genomic stability. Its precise and dynamic assembly is pivotal for its function. Spliceosome malfunctions can lead to developmental abnormalities and potentially contribute to tumorigenesis. The specific role of the spliceosome in B cell development is poorly understood. Here, we reveal that the spliceosomal U2 snRNP component PHD finger protein 5A (Phf5a) is vital for early B cell development. Loss of Phf5a results in pronounced defects in B cell development, causing an arrest at the transition from pre-pro-B to early pro-B cell stage in the bone marrow of mutant mice. Phf5a-deficient B cells exhibit impaired immunoglobulin heavy (IgH) chain expression due to defective V-to-DJ gene rearrangement. Mechanistically, our findings suggest that Phf5a facilitates IgH gene rearrangement by regulating the activity of recombination-activating gene endonuclease and influencing chromatin interactions at the Igh locus.
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Affiliation(s)
- Rui Zhang
- Department of Immunology and Microbiology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Daoqin Wang
- Department of Immunology and Microbiology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Gui-Xin Ruan
- Medical School, Taizhou University, Taizhou 318000, China
| | - Ruisi Wang
- Department of Immunology and Microbiology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Yuxing Li
- Department of Immunology and Microbiology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Wenjing Chen
- Department of Immunology and Microbiology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Hengjun Huang
- Department of Immunology and Microbiology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Jing Wang
- Department of Immunology and Microbiology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Limin Meng
- Department of Immunology and Microbiology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Zhijian Zhu
- Department of Immunology and Microbiology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Dengfeng Lei
- Department of Ophthalmology, Southern University of Science and Technology Hospital, Shenzhen 518055, China
| | - Shengli Xu
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A*STAR), 8A Biomedical Grove, Immunos, Singapore 138648, Republic of Singapore
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 2 Medical Drive MD9, Singapore 117593, Republic of Singapore
| | - Xijun Ou
- Department of Immunology and Microbiology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
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4
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Allen D, Knop O, Itkowitz B, Kalter N, Rosenberg M, Iancu O, Beider K, Lee YN, Nagler A, Somech R, Hendel A. CRISPR-Cas9 engineering of the RAG2 locus via complete coding sequence replacement for therapeutic applications. Nat Commun 2023; 14:6771. [PMID: 37891182 PMCID: PMC10611791 DOI: 10.1038/s41467-023-42036-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 09/28/2023] [Indexed: 10/29/2023] Open
Abstract
RAG2-SCID is a primary immunodeficiency caused by mutations in Recombination-activating gene 2 (RAG2), a gene intimately involved in the process of lymphocyte maturation and function. ex-vivo manipulation of a patient's own hematopoietic stem and progenitor cells (HSPCs) using CRISPR-Cas9/rAAV6 gene editing could provide a therapeutic alternative to the only current treatment, allogeneic hematopoietic stem cell transplantation (HSCT). Here we show an innovative RAG2 correction strategy that replaces the entire endogenous coding sequence (CDS) for the purpose of preserving the critical endogenous spatiotemporal gene regulation and locus architecture. Expression of the corrective transgene leads to successful development into CD3+TCRαβ+ and CD3+TCRγδ+ T cells and promotes the establishment of highly diverse TRB and TRG repertoires in an in-vitro T-cell differentiation platform. Thus, our proof-of-concept study holds promise for safer gene therapy techniques of tightly regulated genes.
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Affiliation(s)
- Daniel Allen
- Institute of Nanotechnology and Advanced Materials, The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, 5290002, Israel
| | - Orli Knop
- Institute of Nanotechnology and Advanced Materials, The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, 5290002, Israel
| | - Bryan Itkowitz
- Institute of Nanotechnology and Advanced Materials, The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, 5290002, Israel
| | - Nechama Kalter
- Institute of Nanotechnology and Advanced Materials, The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, 5290002, Israel
| | - Michael Rosenberg
- Institute of Nanotechnology and Advanced Materials, The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, 5290002, Israel
| | - Ortal Iancu
- Institute of Nanotechnology and Advanced Materials, The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, 5290002, Israel
| | - Katia Beider
- The Division of Hematology and Bone Marrow Transplantation, Chaim Sheba Medical Center, Tel-Hashomer, Ramat Gan, 5266202, Israel
| | - Yu Nee Lee
- Sackler Faculty of Medicine, Tel Aviv University, 6997801, Tel Aviv, Israel
- Pediatric Department A and the Immunology Service, Jeffrey Modell Foundation Center, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Ramat Gan, 5266202, Israel
| | - Arnon Nagler
- The Division of Hematology and Bone Marrow Transplantation, Chaim Sheba Medical Center, Tel-Hashomer, Ramat Gan, 5266202, Israel
- Sackler Faculty of Medicine, Tel Aviv University, 6997801, Tel Aviv, Israel
| | - Raz Somech
- Sackler Faculty of Medicine, Tel Aviv University, 6997801, Tel Aviv, Israel
- Pediatric Department A and the Immunology Service, Jeffrey Modell Foundation Center, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Ramat Gan, 5266202, Israel
| | - Ayal Hendel
- Institute of Nanotechnology and Advanced Materials, The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, 5290002, Israel.
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5
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Hoolehan W, Harris JC, Rodgers KK. Molecular Mechanisms of DNA Sequence Selectivity in V(D)J Recombination. ACS OMEGA 2023; 8:34206-34214. [PMID: 37779976 PMCID: PMC10536018 DOI: 10.1021/acsomega.3c05601] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 09/07/2023] [Indexed: 10/03/2023]
Abstract
Antigen receptor (AgR) diversity is central to the ability of adaptive immunity in jawed vertebrates to protect against pathogenic agents. The production of highly diverse AgR repertoires is initiated during B and T cell lymphopoiesis by V(D)J recombination, which assembles the receptor genes from component gene segments in a cut-and-paste recombination reaction. Recombination activating proteins, RAG1 and RAG2 (RAG1/2), catalyze V(D)J recombination by cleaving adjacent to recombination signal sequences (RSSs) that flank AgR gene segments. Previous studies defined the consensus RSS as containing conserved heptamer and nonamer sequences separated by a less conserved 12 or 23 base-pair spacer sequence. However, many RSSs deviate from the consensus sequence, and the molecular mechanism for semiselective V(D)J recombination specificity is unknown. The modulation of chromatin structure during V(D)J recombination is essential in the formation of diverse AgRs in adaptive immunity while also reducing the likelihood for off-target recombination events that can result in chromosomal aberrations and genomic instability. Here we review what is presently known regarding mechanisms that facilitate assembly of RAG1/2 with RSSs, the ensuing conformational changes required for DNA cleavage activity, and how the readout of the RSS sequence affects reaction efficiency.
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Affiliation(s)
- Walker Hoolehan
- Department
of Biochemistry and Molecular Biology, Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, United States
| | - Justin C. Harris
- Department
of Biochemistry and Molecular Biology, Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, United States
| | - Karla K. Rodgers
- Department
of Biochemistry and Molecular Biology, Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, United States
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6
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Liang Z, Zhao L, Ye AY, Lin SG, Zhang Y, Guo C, Dai HQ, Ba Z, Alt FW. Contribution of the IGCR1 regulatory element and the 3' Igh CTCF-binding elements to regulation of Igh V(D)J recombination. Proc Natl Acad Sci U S A 2023; 120:e2306564120. [PMID: 37339228 PMCID: PMC10293834 DOI: 10.1073/pnas.2306564120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Accepted: 05/12/2023] [Indexed: 06/22/2023] Open
Abstract
Immunoglobulin heavy chain variable region exons are assembled in progenitor-B cells, from VH, D, and JH gene segments located in separate clusters across the Igh locus. RAG endonuclease initiates V(D)J recombination from a JH-based recombination center (RC). Cohesin-mediated extrusion of upstream chromatin past RC-bound RAG presents Ds for joining to JHs to form a DJH-RC. Igh has a provocative number and organization of CTCF-binding elements (CBEs) that can impede loop extrusion. Thus, Igh has two divergently oriented CBEs (CBE1 and CBE2) in the IGCR1 element between the VH and D/JH domains, over 100 CBEs across the VH domain convergent to CBE1, and 10 clustered 3'Igh-CBEs convergent to CBE2 and VH CBEs. IGCR1 CBEs segregate D/JH and VH domains by impeding loop extrusion-mediated RAG-scanning. Downregulation of WAPL, a cohesin unloader, in progenitor-B cells neutralizes CBEs, allowing DJH-RC-bound RAG to scan the VH domain and perform VH-to-DJH rearrangements. To elucidate potential roles of IGCR1-based CBEs and 3'Igh-CBEs in regulating RAG-scanning and elucidate the mechanism of the ordered transition from D-to-JH to VH-to-DJH recombination, we tested effects of inverting and/or deleting IGCR1 or 3'Igh-CBEs in mice and/or progenitor-B cell lines. These studies revealed that normal IGCR1 CBE orientation augments RAG-scanning impediment activity and suggest that 3'Igh-CBEs reinforce ability of the RC to function as a dynamic loop extrusion impediment to promote optimal RAG scanning activity. Finally, our findings indicate that ordered V(D)J recombination can be explained by a gradual WAPL downregulation mechanism in progenitor-B cells as opposed to a strict developmental switch.
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Affiliation(s)
- Zhuoyi Liang
- HHMI, Boston Children’s Hospital, Boston, MA02115
- Program in Cellular and Molecular Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, MA02115
- Department of Genetics, Harvard Medical School, Boston, MA02115
| | - Lijuan Zhao
- HHMI, Boston Children’s Hospital, Boston, MA02115
- Program in Cellular and Molecular Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, MA02115
- Department of Genetics, Harvard Medical School, Boston, MA02115
| | - Adam Yongxin Ye
- HHMI, Boston Children’s Hospital, Boston, MA02115
- Program in Cellular and Molecular Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, MA02115
- Department of Genetics, Harvard Medical School, Boston, MA02115
| | - Sherry G. Lin
- HHMI, Boston Children’s Hospital, Boston, MA02115
- Program in Cellular and Molecular Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, MA02115
- Department of Genetics, Harvard Medical School, Boston, MA02115
| | - Yiwen Zhang
- HHMI, Boston Children’s Hospital, Boston, MA02115
- Program in Cellular and Molecular Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, MA02115
- Department of Genetics, Harvard Medical School, Boston, MA02115
| | - Chunguang Guo
- HHMI, Boston Children’s Hospital, Boston, MA02115
- Program in Cellular and Molecular Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, MA02115
- Department of Genetics, Harvard Medical School, Boston, MA02115
| | - Hai-Qiang Dai
- HHMI, Boston Children’s Hospital, Boston, MA02115
- Program in Cellular and Molecular Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, MA02115
- Department of Genetics, Harvard Medical School, Boston, MA02115
| | - Zhaoqing Ba
- HHMI, Boston Children’s Hospital, Boston, MA02115
- Program in Cellular and Molecular Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, MA02115
- Department of Genetics, Harvard Medical School, Boston, MA02115
| | - Frederick W. Alt
- HHMI, Boston Children’s Hospital, Boston, MA02115
- Program in Cellular and Molecular Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, MA02115
- Department of Genetics, Harvard Medical School, Boston, MA02115
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7
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Liang Z, Zhao L, Yongxin Ye A, Lin SG, Zhang Y, Guo C, Dai HQ, Ba Z, Alt FW. Contribution of the IGCR1 regulatory element and the 3 'Igh CBEs to Regulation of Igh V(D)J Recombination. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.21.537836. [PMID: 37163018 PMCID: PMC10168220 DOI: 10.1101/2023.04.21.537836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Immunoglobulin heavy chain variable region exons are assembled in progenitor-B cells, from V H , D, and J H gene segments located in separate clusters across the Igh locus. RAG endonuclease initiates V(D)J recombination from a J H -based recombination center (RC). Cohesin-mediated extrusion of upstream chromatin past RC-bound RAG presents Ds for joining to J H s to form a DJ H -RC. Igh has a provocative number and organization of CTCF-binding-elements (CBEs) that can impede loop extrusion. Thus, Igh has two divergently oriented CBEs (CBE1 and CBE2) in the IGCR1 element between the V H and D/J H domains, over 100 CBEs across the V H domain convergent to CBE1, and 10 clustered 3' Igh -CBEs convergent to CBE2 and V H CBEs. IGCR1 CBEs segregate D/J H and V H domains by impeding loop extrusion-mediated RAG-scanning. Down-regulation of WAPL, a cohesin unloader, in progenitor-B cells neutralizes CBEs, allowing DJ H -RC-bound RAG to scan the VH domain and perform VH-to-DJH rearrangements. To elucidate potential roles of IGCR1-based CBEs and 3' Igh -CBEs in regulating RAG-scanning and elucidate the mechanism of the "ordered" transition from D-to-J H to V H -to-DJ H recombination, we tested effects of deleting or inverting IGCR1 or 3' Igh -CBEs in mice and/or progenitor-B cell lines. These studies revealed that normal IGCR1 CBE orientation augments RAG-scanning impediment activity and suggest that 3' Igh -CBEs reinforce ability of the RC to function as a dynamic loop extrusion impediment to promote optimal RAG scanning activity. Finally, our findings indicate that ordered V(D)J recombination can be explained by a gradual WAPL down-regulation mechanism in progenitor B cells as opposed to a strict developmental switch. SIGNIFICANCE STATEMENT To counteract diverse pathogens, vertebrates evolved adaptive immunity to generate diverse antibody repertoires through a B lymphocyte-specific somatic gene rearrangement process termed V(D)J recombination. Tight regulation of the V(D)J recombination process is vital to generating antibody diversity and preventing off-target activities that can predispose the oncogenic translocations. Recent studies have demonstrated V(D)J rearrangement is driven by cohesin-mediated chromatin loop extrusion, a process that establishes genomic loop domains by extruding chromatin, predominantly, between convergently-oriented CTCF looping factor-binding elements (CBEs). By deleting and inverting CBEs within a critical antibody heavy chain gene locus developmental control region and a loop extrusion chromatin-anchor at the downstream end of this locus, we reveal how these elements developmentally contribute to generation of diverse antibody repertoires.
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8
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Zhang X, Kang X, Yang M, Cai Z, Song Y, Zhou X, Cao J, Wang C, Huang K, Peng Y, He J, Xiao Z. A variant of RAG1 gene identified in severe combined immunodeficiency: a case report. BMC Pediatr 2023; 23:56. [PMID: 36732712 PMCID: PMC9896705 DOI: 10.1186/s12887-022-03822-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 12/24/2022] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND The recombination-activating gene 1 (RAG1) protein is essential for the V (variable)-D (diversity)-J (joining) recombination process. Mutations in RAG1 have been reported to be associated with several types of immune disorders. Typical clinical features driven by RAG1 variants include persistent infections, severe lymphopenia, and decreased immunoglobulin levels . CASE PRESENTATION In this study, a 2-month-24-days-old infant with recurrent fever was admitted to our hospital with multiple infections and absence of T and B lymphocytes. The infant was diagnosed with severe combined immunodeficiency (SCID). A homozygous variation c.2147G>A (NM_000448.2: exonme2: c.2147G>A (p.Arg716Gln)) was identified in the RAG1 gene using whole-exome sequencing and Sanger sequencing. The predicted 3D structure of variant RAG1 indicated altered protein stability. Additionally, decreased expression of variant RAG1 gene was detected at both the mRNA and protein levels. CONCLUSIONS Our study identified a novel homozygous variant in RAG1 gene that causes SCID. This finding expands the variant spectrum of RAG1 in SCID and provides further evidence for the clinical diagnosis of SCID.
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Affiliation(s)
- Xinping Zhang
- grid.440223.30000 0004 1772 5147Department of Pediatric Intensive Care Unit of Hunan Children’s Hospital, Changsha, Hunan People’s Republic of China
| | - Xiayan Kang
- grid.440223.30000 0004 1772 5147Department of Pediatric Intensive Care Unit of Hunan Children’s Hospital, Changsha, Hunan People’s Republic of China
| | - Meiyu Yang
- grid.440223.30000 0004 1772 5147Department of Pediatric Intensive Care Unit of Hunan Children’s Hospital, Changsha, Hunan People’s Republic of China
| | - Zili Cai
- grid.440223.30000 0004 1772 5147Department of Pediatric Intensive Care Unit of Hunan Children’s Hospital, Changsha, Hunan People’s Republic of China
| | - Yulei Song
- grid.440223.30000 0004 1772 5147Department of Pediatric Intensive Care Unit of Hunan Children’s Hospital, Changsha, Hunan People’s Republic of China
| | - Xiong Zhou
- grid.440223.30000 0004 1772 5147Department of Pediatric Intensive Care Unit of Hunan Children’s Hospital, Changsha, Hunan People’s Republic of China
| | - Jianshe Cao
- grid.440223.30000 0004 1772 5147Department of Pediatric Intensive Care Unit of Hunan Children’s Hospital, Changsha, Hunan People’s Republic of China
| | - Chengjuan Wang
- grid.440223.30000 0004 1772 5147Department of Pediatric Intensive Care Unit of Hunan Children’s Hospital, Changsha, Hunan People’s Republic of China
| | - Kang Huang
- grid.440223.30000 0004 1772 5147Department of Pediatric Intensive Care Unit of Hunan Children’s Hospital, Changsha, Hunan People’s Republic of China
| | - Yani Peng
- grid.440223.30000 0004 1772 5147Department of Pediatric Intensive Care Unit of Hunan Children’s Hospital, Changsha, Hunan People’s Republic of China
| | - Jie He
- grid.440223.30000 0004 1772 5147Department of Pediatric Intensive Care Unit of Hunan Children’s Hospital, Changsha, Hunan People’s Republic of China
| | - Zhenghui Xiao
- Department of Pediatric Intensive Care Unit of Hunan Children's Hospital, Changsha, Hunan, People's Republic of China.
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9
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Kenter AL, Priyadarshi S, Drake EB. Locus architecture and RAG scanning determine antibody diversity. Trends Immunol 2023; 44:119-128. [PMID: 36706738 PMCID: PMC10128066 DOI: 10.1016/j.it.2022.12.005] [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: 12/01/2022] [Revised: 12/07/2022] [Accepted: 12/08/2022] [Indexed: 01/27/2023]
Abstract
Diverse mammalian antibody repertoires are produced via distant genomic contacts involving immunoglobulin Igh variable (V), diversity (D), and joining (J) gene segments and result in V(D)J recombination. How such interactions determine V gene usage remains unclear. The recombination-activating gene (RAG) chromatin scanning model posits that RAG recombinase bound to the recombination center (RC) linearly tracks along chromatin by means of cohesin-mediated loop extrusion; a proposition supported by cohesin depletion studies. A mechanistic role for chromatin loop extrusion has also been implicated for Igh locus contraction. In this opinion, we provide perspective on how loop extrusion interfaces with the 3D conformation of the Igh locus and newly identified enhancers that regionally regulate VH gene usage during V(D)J recombination, shaping the preselected repertoire.
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Affiliation(s)
- Amy L Kenter
- Department of Microbiology and Immunology, University of Illinois College of Medicine, Chicago, IL 60612-7344, USA.
| | - Saurabh Priyadarshi
- Department of Microbiology and Immunology, University of Illinois College of Medicine, Chicago, IL 60612-7344, USA
| | - Ellen B Drake
- Department of Microbiology and Immunology, University of Illinois College of Medicine, Chicago, IL 60612-7344, USA
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10
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Wu B, Zhang Q, Hong P, Liu L, Peng H, Xia C, Wang T, Wang Y, Weng Q, Liu X, Geng Y, Wang J, Wu H. Antigen-specific TCR-T cells from Rag2 gene-deleted pluripotent stem cells impede solid tumour growth in a mouse model. Cell Prolif 2023; 56:e13389. [PMID: 36592612 PMCID: PMC10068938 DOI: 10.1111/cpr.13389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 12/08/2022] [Accepted: 12/12/2022] [Indexed: 01/04/2023] Open
Abstract
The technology of adoptive transfer of T-cell receptor (TCR) engineered T cells is wildly investigated as it has the potential to treat solid cancers. However, the therapeutic application of TCR-T cells is hampered by the poor quality derived mainly from patients' peripheral blood, as well as heterogeneous TCRs caused by the mismatch between transgenic and endogenous TCRs. To improve the homogeneity, antigen-specificity and reduce possible autoreactivity, here we developed a technique to generate antigen-specific T cells from Rag2 gene-deleted pluripotent stem cells (PSCs) and further measured their anti-tumour efficacy. PSCs were first targeted with OT1 TCR into the Rag2 locus to prevent TCR rearrangement during T-cell development. The engineered PSCs were then differentiated through a two-step strategy, in vitro generation of haematopoietic progenitor cells, and in vivo development and maturation of TCR-T cells. Finally, the response to tumour cells was assessed in vitro and in vivo. The regenerated OT1-iT displayed monoclonal antigen-specific TCR expression, and phonotypic normalities in the spleen and lymph node tissues. Importantly, the OT1-iT cells eliminated tumour cells while releasing specific cytokines in vitro. Furthermore, adoptive transfer of OT1-iT cells suppresses solid tumour growth in tumour-bearing animals. Our study presents a novel and straightforward strategy for producing antigen-specific TCR-T cells in vivo from PSCs, allowing for allogeneic transplantation and therapy of solid tumours.
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Affiliation(s)
- Bingyan Wu
- CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Qi Zhang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute for Stem Cell and Regeneration, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Pingshan Hong
- Liwan People's Hospital of Guangzhou, Guangzhou, China
| | - Lijuan Liu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute for Stem Cell and Regeneration, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Huan Peng
- CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Chengxiang Xia
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, China
| | - Tongjie Wang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute for Stem Cell and Regeneration, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Yao Wang
- CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Qitong Weng
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute for Stem Cell and Regeneration, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Xiaofei Liu
- CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Yang Geng
- CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Jinyong Wang
- CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.,University of Chinese Academy of Sciences, Beijing, China.,State Key Laboratory of Stem Cell and Reproductive Biology, Institute for Stem Cell and Regeneration, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, China.,Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou, China
| | - Hongling Wu
- CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
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11
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Watanabe G, Lieber MR. Dynamics of the Artemis and DNA-PKcs Complex in the Repair of Double-Strand Breaks. J Mol Biol 2022; 434:167858. [PMID: 36270581 PMCID: PMC9940633 DOI: 10.1016/j.jmb.2022.167858] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 10/11/2022] [Accepted: 10/11/2022] [Indexed: 11/05/2022]
Abstract
Pathologic chromosome breaks occur in human dividing cells ∼10 times per day, and physiologic breaks occur in each lymphoid cell many additional times per day. Nonhomologous DNA end joining (NHEJ) is the major pathway for the repair of all of these double-strand breaks (DSBs) during most of the cell cycle. Nearly all broken DNA ends require trimming before they can be suitable for joining by ligation. Artemis is the major nuclease for this purpose. Artemis is tightly regulated by one of the largest protein kinases, which tethers Artemis to its surface. This kinase is called DNA-dependent protein kinase catalytic subunit (or DNA-PKcs) because it is only active when it encounters a broken DNA end. With this activation, DNA-PKcs permits the Artemis catalytic domain to enter a large cavity in the center of DNA-PKcs. Given this remarkably tight supervision of Artemis by DNA-PKcs, it is an appropriate time to ask what we know about the Artemis:DNA-PKcs complex, as we integrate recent structural information with the biochemistry of the complex and how this relates to other NHEJ proteins and to V(D)J recombination in the immune system.
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Affiliation(s)
- Go Watanabe
- Department of Pathology, Department of Biochemistry & Molecular Biology, Department of Molecular Microbiology & Immunology, and Section of Molecular & Computational Biology, USC Norris Comprehensive Cancer Center, University of Southern California Keck School of Medicine, 1441 Eastlake Ave, Rm. 5428, Los Angeles, CA 90089, USA
| | - Michael R Lieber
- Department of Pathology, Department of Biochemistry & Molecular Biology, Department of Molecular Microbiology & Immunology, and Section of Molecular & Computational Biology, USC Norris Comprehensive Cancer Center, University of Southern California Keck School of Medicine, 1441 Eastlake Ave, Rm. 5428, Los Angeles, CA 90089, USA.
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12
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Anderson MK, da Rocha JDB. Direct regulation of TCR rearrangement and expression by E proteins during early T cell development. WIREs Mech Dis 2022; 14:e1578. [PMID: 35848146 PMCID: PMC9669112 DOI: 10.1002/wsbm.1578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 05/22/2022] [Accepted: 06/17/2022] [Indexed: 11/12/2022]
Abstract
γδ T cells are widely distributed throughout mucosal and epithelial cell-rich tissues and are an important early source of IL-17 in response to several pathogens. Like αβ T cells, γδ T cells undergo a stepwise process of development in the thymus that requires recombination of genome-encoded segments to assemble mature T cell receptor (TCR) genes. This process is tightly controlled on multiple levels to enable TCR segment assembly while preventing the genomic instability inherent in the double-stranded DNA breaks that occur during this process. Each TCR locus has unique aspects in its structure and requirements, with different types of regulation before and after the αβ/γδ T cell fate choice. It has been known that Runx and Myb are critical transcriptional regulators of TCRγ and TCRδ expression, but the roles of E proteins in TCRγ and TCRδ regulation have been less well explored. Multiple lines of evidence show that E proteins are involved in TCR expression at many different levels, including the regulation of Rag recombinase gene expression and protein stability, induction of germline V segment expression, chromatin remodeling, and restriction of the fetal and adult γδTCR repertoires. Importantly, E proteins interact directly with the cis-regulatory elements of the TCRγ and TCRδ loci, controlling the predisposition of a cell to become an αβ T cell or a γδ T cell, even before the lineage-dictating TCR signaling events. This article is categorized under: Immune System Diseases > Stem Cells and Development Immune System Diseases > Genetics/Genomics/Epigenetics.
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Affiliation(s)
- Michele K Anderson
- Department Immunology, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
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13
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The role of chromatin loop extrusion in antibody diversification. Nat Rev Immunol 2022; 22:550-566. [PMID: 35169260 PMCID: PMC9376198 DOI: 10.1038/s41577-022-00679-3] [Citation(s) in RCA: 43] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/12/2022] [Indexed: 12/15/2022]
Abstract
Cohesin mediates chromatin loop formation across the genome by extruding chromatin between convergently oriented CTCF-binding elements. Recent studies indicate that cohesin-mediated loop extrusion in developing B cells presents immunoglobulin heavy chain (Igh) variable (V), diversity (D) and joining (J) gene segments to RAG endonuclease through a process referred to as RAG chromatin scanning. RAG initiates V(D)J recombinational joining of these gene segments to generate the large number of different Igh variable region exons that are required for immune responses to diverse pathogens. Antigen-activated mature B cells also use chromatin loop extrusion to mediate the synapsis, breakage and end joining of switch regions flanking Igh constant region exons during class-switch recombination, which allows for the expression of different antibody constant region isotypes that optimize the functions of antigen-specific antibodies to eliminate pathogens. Here, we review recent advances in our understanding of chromatin loop extrusion during V(D)J recombination and class-switch recombination at the Igh locus.
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14
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Luo S, Qiao R, Zhang X. DNA Damage Response and Repair in Adaptive Immunity. Front Cell Dev Biol 2022; 10:884873. [PMID: 35663402 PMCID: PMC9157429 DOI: 10.3389/fcell.2022.884873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 03/31/2022] [Indexed: 11/16/2022] Open
Abstract
The diversification of B-cell receptor (BCR), as well as its secreted product, antibody, is a hallmark of adaptive immunity, which has more specific roles in fighting against pathogens. The antibody diversification is from recombination-activating gene (RAG)-initiated V(D)J recombination, activation-induced cytidine deaminase (AID)-initiated class switch recombination (CSR), and V(D)J exon somatic hypermutation (SHM). The proper repair of RAG- and AID-initiated DNA lesions and double-strand breaks (DSBs) is required for promoting antibody diversification, suppressing genomic instability, and oncogenic translocations. DNA damage response (DDR) factors and DSB end-joining factors are recruited to the RAG- and AID-initiated DNA lesions and DSBs to coordinately resolve them for generating productive recombination products during antibody diversification. Recently, cohesin-mediated loop extrusion is proposed to be the underlying mechanism of V(D)J recombination and CSR, which plays essential roles in promoting the orientation-biased deletional end-joining . Here, we will discuss the mechanism of DNA damage repair in antibody diversification.
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Affiliation(s)
- Sha Luo
- Biomedical Pioneering Innovation Center, Innovation Center for Genomics, Peking University, Beijing, China
- Academy for Advanced Interdisciplinery Studies, Peking University, Beijing, China
| | - Ruolin Qiao
- Biomedical Pioneering Innovation Center, Innovation Center for Genomics, Peking University, Beijing, China
- Academy for Advanced Interdisciplinery Studies, Peking University, Beijing, China
| | - Xuefei Zhang
- Biomedical Pioneering Innovation Center, Innovation Center for Genomics, Peking University, Beijing, China
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15
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Christie SM, Fijen C, Rothenberg E. V(D)J Recombination: Recent Insights in Formation of the Recombinase Complex and Recruitment of DNA Repair Machinery. Front Cell Dev Biol 2022; 10:886718. [PMID: 35573672 PMCID: PMC9099191 DOI: 10.3389/fcell.2022.886718] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 04/01/2022] [Indexed: 11/13/2022] Open
Abstract
V(D)J recombination is an essential mechanism of the adaptive immune system, producing a diverse set of antigen receptors in developing lymphocytes via regulated double strand DNA break and subsequent repair. DNA cleavage is initiated by the recombinase complex, consisting of lymphocyte specific proteins RAG1 and RAG2, while the repair phase is completed by classical non-homologous end joining (NHEJ). Many of the individual steps of this process have been well described and new research has increased the scale to understand the mechanisms of initiation and intermediate stages of the pathway. In this review we discuss 1) the regulatory functions of RAGs, 2) recruitment of RAGs to the site of recombination and formation of a paired complex, 3) the transition from a post-cleavage complex containing RAGs and cleaved DNA ends to the NHEJ repair phase, and 4) the potential redundant roles of certain factors in repairing the break. Regulatory (non-core) domains of RAGs are not necessary for catalytic activity, but likely influence recruitment and stabilization through interaction with modified histones and conformational changes. To form long range paired complexes, recent studies have found evidence in support of large scale chromosomal contraction through various factors to utilize diverse gene segments. Following the paired cleavage event, four broken DNA ends must now make a regulated transition to the repair phase, which can be controlled by dynamic conformational changes and post-translational modification of the factors involved. Additionally, we examine the overlapping roles of certain NHEJ factors which allows for prevention of genomic instability due to incomplete repair in the absence of one, but are lethal in combined knockouts. To conclude, we focus on the importance of understanding the detail of these processes in regards to off-target recombination or deficiency-mediated clinical manifestations.
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Affiliation(s)
- Shaun M. Christie
- *Correspondence: Shaun M. Christie, ; Carel Fijen, ; Eli Rothenberg,
| | - Carel Fijen
- *Correspondence: Shaun M. Christie, ; Carel Fijen, ; Eli Rothenberg,
| | - Eli Rothenberg
- *Correspondence: Shaun M. Christie, ; Carel Fijen, ; Eli Rothenberg,
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16
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Ruan GX, Li Y, Chen W, Huang H, Zhang R, Chen C, Lam KP, Xu S, Ou X. The spliceosome component Usp39 controls B cell development by regulating immunoglobulin gene rearrangement. Cell Rep 2022; 38:110338. [PMID: 35139388 DOI: 10.1016/j.celrep.2022.110338] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 11/18/2021] [Accepted: 01/13/2022] [Indexed: 12/17/2022] Open
Abstract
The spliceosome is a large ribonucleoprotein complex responsible for pre-mRNA splicing and genome stability maintenance. Disruption of the spliceosome activity may lead to developmental disorders and tumorigenesis. However, the physiological role that the spliceosome plays in B cell development and function is still poorly defined. Here, we demonstrate that ubiquitin-specific peptidase 39 (Usp39), a spliceosome component of the U4/U6.U5 tri-snRNP complex, is essential for B cell development. Ablation of Usp39 in B cell lineage blocks pre-pro-B to pro-B cell transition in the bone marrow, leading to a profound reduction of mature B cells in the periphery. We show that Usp39 specifically regulates immunoglobulin gene rearrangement in a spliceosome-dependent manner, which involves modulating chromatin interactions at the Igh locus. Moreover, our results indicate that Usp39 deletion reduces the pre-malignant B cells in Eμ-Myc transgenic mice and significantly improves their survival.
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Affiliation(s)
- Gui-Xin Ruan
- Harbin Institute of Technology, Harbin 150001, China; Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Yuxing Li
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Wenjing Chen
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Hengjun Huang
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Rui Zhang
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Changxu Chen
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Kong-Peng Lam
- Singapore Immunology Network, Agency for Science, Technology and Research, Singapore 138648, Singapore; Departments of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599, Singapore; Department of Pediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599, Singapore
| | - Shengli Xu
- Singapore Immunology Network, Agency for Science, Technology and Research, Singapore 138648, Singapore; Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599, Singapore
| | - Xijun Ou
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China.
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17
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Kaiser C, Bradu A, Gamble N, Caldwell JA, Koh AS. AIRE in context: Leveraging chromatin plasticity to trigger ectopic gene expression. Immunol Rev 2022; 305:59-76. [PMID: 34545959 PMCID: PMC9250823 DOI: 10.1111/imr.13026] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Accepted: 08/26/2021] [Indexed: 12/22/2022]
Abstract
The emergence of antigen receptor diversity in clonotypic lymphocytes drove the evolution of a novel gene, Aire, that enabled the adaptive immune system to discriminate foreign invaders from self-constituents. AIRE functions in the epithelial cells of the thymus to express genes highly restricted to alternative cell lineages. This somatic plasticity facilitates the selection of a balanced repertoire of T cells that protects the host from harmful self-reactive clones, yet maintains a wide range of affinities for virtually any foreign antigen. Here, we review the latest understanding of AIRE's molecular actions with a focus on its interplay with chromatin. We argue that AIRE is a multi-valent chromatin effector that acts late in the transcription cycle to modulate the activity of previously poised non-coding regulatory elements of tissue-specific genes. We postulate a role for chromatin instability-caused in part by ATP-dependent chromatin remodeling-that variably sets the scope of the accessible landscape on which AIRE can act. We highlight AIRE's intrinsic repressive function and its relevance in providing feedback control. We synthesize these recent advances into a putative model for the mechanistic modes by which AIRE triggers ectopic transcription for immune repertoire selection.
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Affiliation(s)
- Caroline Kaiser
- Department of Pathology, University of Chicago, Chicago, Illinois, USA
- Department of Human Genetics, University of Chicago, Chicago, Illinois, USA
| | - Alexandra Bradu
- Department of Pathology, University of Chicago, Chicago, Illinois, USA
| | - Noah Gamble
- Department of Pathology, University of Chicago, Chicago, Illinois, USA
- Graduate Program in Biophysical Sciences, University of Chicago, Chicago, Illinois, USA
| | - Jason A. Caldwell
- Department of Pathology, University of Chicago, Chicago, Illinois, USA
| | - Andrew S. Koh
- Department of Pathology, University of Chicago, Chicago, Illinois, USA
- Institute for Biophysical Dynamics, University of Chicago, Chicago, Illinois, USA
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18
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Dauba A, Khamlichi AA. Long-Range Control of Class Switch Recombination by Transcriptional Regulatory Elements. Front Immunol 2021; 12:738216. [PMID: 34594340 PMCID: PMC8477019 DOI: 10.3389/fimmu.2021.738216] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 08/17/2021] [Indexed: 01/18/2023] Open
Abstract
Immunoglobulin class switch recombination (CSR) plays a crucial role in adaptive immune responses through a change of the effector functions of antibodies and is triggered by T-cell-dependent as well as T-cell-independent antigens. Signals generated following encounter with each type of antigen direct CSR to different isotypes. At the genomic level, CSR occurs between highly repetitive switch sequences located upstream of the constant gene exons of the immunoglobulin heavy chain locus. Transcription of switch sequences is mandatory for CSR and is induced in a stimulation-dependent manner. Switch transcription takes place within dynamic chromatin domains and is regulated by long-range regulatory elements which promote alignment of partner switch regions in CSR centers. Here, we review recent work and models that account for the function of long-range transcriptional regulatory elements and the chromatin-based mechanisms involved in the control of CSR.
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Affiliation(s)
- Audrey Dauba
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, Université Paul Sabatier, Toulouse, France
| | - Ahmed Amine Khamlichi
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, Université Paul Sabatier, Toulouse, France
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19
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Ghorbani A, Quinlan EM, Larijani M. Evolutionary Comparative Analyses of DNA-Editing Enzymes of the Immune System: From 5-Dimensional Description of Protein Structures to Immunological Insights and Applications to Protein Engineering. Front Immunol 2021; 12:642343. [PMID: 34135887 PMCID: PMC8201067 DOI: 10.3389/fimmu.2021.642343] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 04/06/2021] [Indexed: 01/02/2023] Open
Abstract
The immune system is unique among all biological sub-systems in its usage of DNA-editing enzymes to introduce targeted gene mutations and double-strand DNA breaks to diversify antigen receptor genes and combat viral infections. These processes, initiated by specific DNA-editing enzymes, often result in mistargeted induction of genome lesions that initiate and drive cancers. Like other molecules involved in human health and disease, the DNA-editing enzymes of the immune system have been intensively studied in humans and mice, with little attention paid (< 1% of published studies) to the same enzymes in evolutionarily distant species. Here, we present a systematic review of the literature on the characterization of one such DNA-editing enzyme, activation-induced cytidine deaminase (AID), from an evolutionary comparative perspective. The central thesis of this review is that although the evolutionary comparative approach represents a minuscule fraction of published works on this and other DNA-editing enzymes, this approach has made significant impacts across the fields of structural biology, immunology, and cancer research. Using AID as an example, we highlight the value of the evolutionary comparative approach in discoveries already made, and in the context of emerging directions in immunology and protein engineering. We introduce the concept of 5-dimensional (5D) description of protein structures, a more nuanced view of a structure that is made possible by evolutionary comparative studies. In this higher dimensional view of a protein's structure, the classical 3-dimensional (3D) structure is integrated in the context of real-time conformations and evolutionary time shifts (4th dimension) and the relevance of these dynamics to its biological function (5th dimension).
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Affiliation(s)
- Atefeh Ghorbani
- Program in Immunology and Infectious Diseases, Department of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada.,Department of Molecular Biology and Biochemistry, Faculty of Science, Simon Fraser University, Burnaby, BC, Canada
| | - Emma M Quinlan
- Program in Immunology and Infectious Diseases, Department of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Mani Larijani
- Program in Immunology and Infectious Diseases, Department of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada.,Department of Molecular Biology and Biochemistry, Faculty of Science, Simon Fraser University, Burnaby, BC, Canada
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20
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Ku70 suppresses alternative end joining in G1-arrested progenitor B cells. Proc Natl Acad Sci U S A 2021; 118:2103630118. [PMID: 34006647 DOI: 10.1073/pnas.2103630118] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Classical nonhomologous end joining (C-NHEJ) repairs DNA double-strand breaks (DSBs) throughout interphase but predominates in G1 phase when homologous recombination is unavailable. Complexes containing the Ku70/80 ("Ku") and XRCC4/ligase IV (Lig4) core C-NHEJ factors are required, respectively, for sensing and joining DSBs. While XRCC4/Lig4 are absolutely required for joining RAG1/2 endonuclease ("RAG")-initiated DSBs during V(D)J recombination in G1-phase progenitor lymphocytes, cycling cells deficient for XRCC4/Lig4 also can join chromosomal DSBs by alternative end-joining (A-EJ) pathways. Restriction of V(D)J recombination by XRCC4/Lig4-mediated joining has been attributed to RAG shepherding V(D)J DSBs exclusively into the C-NHEJ pathway. Here, we report that A-EJ of DSB ends generated by RAG1/2, Cas9:gRNA, and Zinc finger endonucleases in Lig4-deficient G1-arrested progenitor B cell lines is suppressed by Ku. Thus, while diverse DSBs remain largely as free broken ends in Lig4-deficient G1-arrested progenitor B cells, deletion of Ku70 increases DSB rejoining and translocation levels to those observed in Ku70-deficient counterparts. Correspondingly, while RAG-initiated V(D)J DSB joining is abrogated in Lig4-deficient G1-arrested progenitor B cell lines, joining of RAG-generated DSBs in Ku70-deficient and Ku70/Lig4 double-deficient lines occurs through a translocation-like A-EJ mechanism. Thus, in G1-arrested, Lig4-deficient progenitor B cells are functionally end-joining suppressed due to Ku-dependent blockage of A-EJ, potentially in association with G1-phase down-regulation of Lig1. Finally, we suggest that differential impacts of Ku deficiency versus Lig4 deficiency on V(D)J recombination, neuronal apoptosis, and embryonic development results from Ku-mediated inhibition of A-EJ in the G1 cell cycle phase in Lig4-deficient developing lymphocyte and neuronal cells.
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21
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Paganini J, Pontarotti P. Search for MHC/TCR-Like Systems in Living Organisms. Front Immunol 2021; 12:635521. [PMID: 34017326 PMCID: PMC8129030 DOI: 10.3389/fimmu.2021.635521] [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: 11/30/2020] [Accepted: 04/07/2021] [Indexed: 12/02/2022] Open
Abstract
Highly polymorphic loci evolved many times over the history of species. These polymorphic loci are involved in three types of functions: kind recognition, self-incompatibility, and the jawed vertebrate adaptive immune system (AIS). In the first part of this perspective, we reanalyzed and described some cases of polymorphic loci reported in the literature. There is a convergent evolution within each functional category and between functional categories, suggesting that the emergence of these self/non-self recognition loci has occurred multiple times throughout the evolutionary history. Most of the highly polymorphic loci are coding for proteins that have a homophilic interaction or heterophilic interaction between linked loci, leading to self or non-self-recognition. The highly polymorphic MHCs, which are involved in the AIS have a different functional mechanism, as they interact through presented self or non-self-peptides with T cell receptors, whose diversity is generated by somatic recombination. Here we propose a mechanism called “the capacity of recognition competition mechanism” that might contribute to the evolution of MHC polymorphism. We propose that the published cases corresponding to these three biological categories represent a small part of what can be found throughout the tree of life, and that similar mechanisms will be found many times, including the one where polymorphic loci interact with somatically generated loci.
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Affiliation(s)
| | - Pierre Pontarotti
- XEGEN, Gemenos, France.,Aix Marseille Université, IRD, APHM, MEPHI, IHU Méditerranée Infection, Marseille, France.,SNC5039 CNRS, Marseille, France
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22
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Repair of programmed DNA lesions in antibody class switch recombination: common and unique features. ACTA ACUST UNITED AC 2021; 2:115-125. [PMID: 33817557 PMCID: PMC7996122 DOI: 10.1007/s42764-021-00035-0] [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] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 02/22/2021] [Accepted: 03/04/2021] [Indexed: 01/31/2023]
Abstract
The adaptive immune system can diversify the antigen receptors to eliminate various pathogens through programmed DNA lesions at antigen receptor genes. In immune diversification, general DNA repair machineries are applied to transform the programmed DNA lesions into gene mutation or recombination events with common and unique features. Here we focus on antibody class switch recombination (CSR), and review the initiation of base damages, the conversion of damaged base to DNA double-strand break, and the ligation of broken ends. With an emphasis on the unique features in CSR, we discuss recent advances in the understanding of DNA repair/replication coordination, and ERCC6L2-mediated deletional recombination. We further elaborate the application of CSR in end-joining, resection and translesion synthesis assays. In the time of the COVID-19 pandemic, we hope it help to understand the generation of therapeutic antibodies.
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23
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Pontarotti P, Abi-Rached L, Yeh JH, Paganini J. Self-Peptidome Variation Shapes Individual Immune Responses. Trends Genet 2020; 37:414-420. [PMID: 33867017 PMCID: PMC7577255 DOI: 10.1016/j.tig.2020.10.001] [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] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 09/28/2020] [Accepted: 10/01/2020] [Indexed: 12/17/2022]
Abstract
The relationship between human genetic variation and disease has not been fully elucidated. According to the present view on infectious diseases pathogen resistance is linked to human leukocyte antigen (HLA) class I/II variants and their individual capacity to present pathogen-derived peptides. Yet, T cell education in the thymus occurs through negative and positive selection, and both processes are controlled by a combination of HLA class I/II variants and peptides from the self. Therefore, the capacity of given HLA class I/II variants to bind pathogen-derived peptides is only one part of the selective process to generate effective immune responses. We thus propose that peptidome variation contributes to shaping T cell receptor (TCR) repertoires and hence individual immune responses, and that this variation represents inherent modulator epitopes. TCR repertoires emerge in the thymus in each individual as T cells undergo positive and negative selection. T cell education is controlled by the combination of HLA class I/II molecules and their peptide pools (peptidome). HLA class I/II molecules are highly plastic in human populations but the peptidome is also a source of variation. Hence combined diversity of HLA class I/II molecules and of self-peptides shapes individual immune responses. Self-peptide variants that affect T cell repertoires represent inherent modulator epitopes.
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Affiliation(s)
- Pierre Pontarotti
- Aix Marseille Université, IRD, APHM, MEPHI, IHU Méditerranée Infection, 19-21 Boulevard Jean Moulin, 13005 Marseille, France; SNC5039 CNRS, 19-21 Boulevard Jean Moulin, 13005 Marseille, France; XEGEN, 15 rue Dominique Piazza, 13420 Gemenos, France.
| | - Laurent Abi-Rached
- Aix Marseille Université, IRD, APHM, MEPHI, IHU Méditerranée Infection, 19-21 Boulevard Jean Moulin, 13005 Marseille, France; SNC5039 CNRS, 19-21 Boulevard Jean Moulin, 13005 Marseille, France
| | - Jung-Hua Yeh
- Prokarium Ltd., London Bioscience Innovation Centre, 2 Royal College Street, London NW1 0NH, UK
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24
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Ba Z, Lou J, Ye AY, Dai HQ, Dring EW, Lin SG, Jain S, Kyritsis N, Kieffer-Kwon KR, Casellas R, Alt FW. CTCF orchestrates long-range cohesin-driven V(D)J recombinational scanning. Nature 2020; 586:305-310. [PMID: 32717742 PMCID: PMC7554077 DOI: 10.1038/s41586-020-2578-0] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 05/18/2020] [Indexed: 12/17/2022]
Abstract
The RAG endonuclease initiates Igh locus V(D)J recombination in progenitor (pro)-B cells1. Upon binding a recombination centre-based JH, RAG scans upstream chromatin via loop extrusion, potentially mediated by cohesin, to locate Ds and assemble a DJH-based recombination centre2. CTCF looping factor-bound elements (CBEs) within IGCR1 upstream of Ds impede RAG scanning3-5; however, their inactivation allows scanning to proximal VHs, where additional CBEs activate rearrangement and impede scanning any further upstream5. Distal VH utilization is thought to involve diffusional access to the recombination centre following large-scale Igh locus contraction6-8. Here we test the potential of linear RAG scanning to mediate distal VH usage in G1-arrested v-Abl pro-B cell lines9, which undergo robust D-to-JH but little VH-to-DJH rearrangements, presumably owing to lack of locus contraction2,5. Through an auxin-inducible approach10, we degraded the cohesin component RAD2110-12 or CTCF12,13 in these G1-arrested lines. Degradation of RAD21 eliminated all V(D)J recombination and interactions associated with RAG scanning, except for reecombination centre-located DQ52-to-JH joining, in which synapsis occurs by diffusion2. Remarkably, while degradation of CTCF suppressed most CBE-based chromatin interactions, it promoted robust recombination centre interactions with, and robust VH-to-DJH joining of, distal VHs, with patterns similar to those of 'locus-contracted' primary pro-B cells. Thus, downmodulation of CTCF-bound scanning-impediment activity promotes cohesin-driven RAG scanning across the 2.7-Mb Igh locus.
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Affiliation(s)
- Zhaoqing Ba
- Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA.
- Department of Genetics, Harvard Medical School, Boston, MA, USA.
| | - Jiangman Lou
- Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Adam Yongxin Ye
- Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Hai-Qiang Dai
- Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Edward W Dring
- Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Sherry G Lin
- Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Suvi Jain
- Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Nia Kyritsis
- Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Kyong-Rim Kieffer-Kwon
- Lymphocyte Nuclear Biology, NIAMS, NIH, Bethesda, MD, USA
- Center of Cancer Research, NCI, NIH, Bethesda, MD, USA
| | - Rafael Casellas
- Lymphocyte Nuclear Biology, NIAMS, NIH, Bethesda, MD, USA.
- Center of Cancer Research, NCI, NIH, Bethesda, MD, USA.
| | - Frederick W Alt
- Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA.
- Department of Genetics, Harvard Medical School, Boston, MA, USA.
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25
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Znc2 module of RAG1 contributes towards structure-specific nuclease activity of RAGs. Biochem J 2020; 477:3567-3582. [PMID: 32886094 DOI: 10.1042/bcj20200361] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 09/01/2020] [Accepted: 09/04/2020] [Indexed: 02/06/2023]
Abstract
Recombination activating genes (RAGs), consisting of RAG1 and RAG2 have ability to perform spatially and temporally regulated DNA recombination in a sequence specific manner. Besides, RAGs also cleave at non-B DNA structures and are thought to contribute towards genomic rearrangements and cancer. The nonamer binding domain of RAG1 binds to the nonamer sequence of the signal sequence during V(D)J recombination. However, deletion of NBD did not affect RAG cleavage on non-B DNA structures. In the present study, we investigated the involvement of other RAG domains when RAGs act as a structure-specific nuclease. Studies using purified central domain (CD) and C-terminal domain (CTD) of the RAG1 showed that CD of RAG1 exhibited high affinity and specific binding to heteroduplex DNA, which was irrespective of the sequence of single-stranded DNA, unlike CTD which showed minimal binding. Furthermore, we show that ZnC2 of RAG1 is crucial for its binding to DNA structures as deletion and point mutations abrogated the binding of CD to heteroduplex DNA. Our results also provide evidence that unlike RAG cleavage on RSS, central domain of RAG1 is sufficient to cleave heteroduplex DNA harbouring pyrimidines, but not purines. Finally, we show that a point mutation in the DDE catalytic motif is sufficient to block the cleavage of CD on heteroduplex DNA. Therefore, in the present study we demonstrate that the while ZnC2 module in central domain of RAG1 is required for binding to non-B DNA structures, active site amino acids are important for RAGs to function as a structure-specific nuclease.
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26
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Shinoda K, Maman Y, Canela A, Schatz DG, Livak F, Nussenzweig A. Intra-Vκ Cluster Recombination Shapes the Ig Kappa Locus Repertoire. Cell Rep 2020; 29:4471-4481.e6. [PMID: 31875554 DOI: 10.1016/j.celrep.2019.11.088] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 11/04/2019] [Accepted: 11/21/2019] [Indexed: 10/25/2022] Open
Abstract
During V(D)J recombination, RAG proteins introduce DNA double-strand breaks (DSBs) at recombination signal sequences (RSSs) that contain either 12- or 23-nt spacer regions. Coordinated 12/23 cleavage predicts that DSBs at variable (V) gene segments should equal the level of breakage at joining (J) segments. Contrary to this, here we report abundant RAG-dependent DSBs at multiple Vκ gene segments independent of V-J rearrangement. We find that a large fraction of Vκ gene segments are flanked not only by a bone-fide 12 spacer but also an overlapping, 23-spacer flipped RSS. These compatible pairs of RSSs mediate recombination and deletion inside the Vκ cluster even in the complete absence of Jκ gene segments and support a V(D)J recombination center (RC) independent of the conventional Jκ-centered RC. We propose an improved model of Vκ-Jκ repertoire formation by incorporating these surprisingly frequent, evolutionarily conserved intra-Vκ cluster recombination events.
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Affiliation(s)
- Kenta Shinoda
- Laboratory of Genome Integrity, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Yaakov Maman
- Laboratory of Genome Integrity, National Cancer Institute, NIH, Bethesda, MD, USA; The Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Andres Canela
- Laboratory of Genome Integrity, National Cancer Institute, NIH, Bethesda, MD, USA; The Hakubi Center for Advanced Research and Radiation Biology Center, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - David G Schatz
- Department of Immunobiology, Yale School of Medicine, New Haven, CT, USA
| | - Ferenc Livak
- Laboratory of Genome Integrity, National Cancer Institute, NIH, Bethesda, MD, USA.
| | - André Nussenzweig
- Laboratory of Genome Integrity, National Cancer Institute, NIH, Bethesda, MD, USA.
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27
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Qiu X, Ma F, Zhao M, Cao Y, Shipp L, Liu A, Dutta A, Singh A, Braikia FZ, De S, Wood WH, Becker KG, Zhou W, Ji H, Zhao K, Atchison ML, Sen R. Altered 3D chromatin structure permits inversional recombination at the IgH locus. SCIENCE ADVANCES 2020; 6:eaaz8850. [PMID: 32851160 PMCID: PMC7428332 DOI: 10.1126/sciadv.aaz8850] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 07/01/2020] [Indexed: 05/05/2023]
Abstract
Immunoglobulin heavy chain (IgH) genes are assembled by two sequential DNA rearrangement events that are initiated by recombination activating gene products (RAG) 1 and 2. Diversity (DH) gene segments rearrange first, followed by variable (VH) gene rearrangements. Here, we provide evidence that each rearrangement step is guided by different rules of engagement between rearranging gene segments. DH gene segments, which recombine by deletion of intervening DNA, must be located within a RAG1/2 scanning domain for efficient recombination. In the absence of intergenic control region 1, a regulatory sequence that delineates the RAG scanning domain on wild-type IgH alleles, VH and DH gene segments can recombine with each other by both deletion and inversion of intervening DNA. We propose that VH gene segments find their targets by distinct mechanisms from those that apply to DH gene segments. These distinctions may underlie differential allelic choice associated with each step of IgH gene assembly.
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Affiliation(s)
- Xiang Qiu
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, Baltimore, MD 21224, USA
| | - Fei Ma
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, Baltimore, MD 21224, USA
| | - Mingming Zhao
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, Baltimore, MD 21224, USA
| | - Yaqiang Cao
- Laboratory of Epigenome Biology, Systems Biology Center, National Heart Lung and Blood Institute, Bethesda, MD 20892, USA
| | - Lillian Shipp
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, Baltimore, MD 21224, USA
| | - Angela Liu
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, Baltimore, MD 21224, USA
| | - Arun Dutta
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, Baltimore, MD 21224, USA
| | - Amit Singh
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, Baltimore, MD 21224, USA
| | - Fatima Zohra Braikia
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, Baltimore, MD 21224, USA
| | - Supriyo De
- Laboratory of Genetics and Genomics, National Institute on Aging, Baltimore, MD 21224, USA
| | - William H. Wood
- Laboratory of Genetics and Genomics, National Institute on Aging, Baltimore, MD 21224, USA
| | - Kevin G. Becker
- Laboratory of Genetics and Genomics, National Institute on Aging, Baltimore, MD 21224, USA
| | - Weiqiang Zhou
- Department of Biostatistics, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, 21205, USA
| | - Hongkai Ji
- Department of Biostatistics, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, 21205, USA
| | - Keji Zhao
- Laboratory of Epigenome Biology, Systems Biology Center, National Heart Lung and Blood Institute, Bethesda, MD 20892, USA
| | - Michael L. Atchison
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Ranjan Sen
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, Baltimore, MD 21224, USA
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28
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Swann JB, Holland SJ, Petersen M, Pietsch TW, Boehm T. The immunogenetics of sexual parasitism. Science 2020; 369:1608-1615. [PMID: 32732279 DOI: 10.1126/science.aaz9445] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 07/17/2020] [Indexed: 01/29/2023]
Abstract
Sexual parasitism has evolved as a distinctive mode of reproduction among deep-sea anglerfishes. The permanent attachment of males to host females observed in these species represents a form of anatomical joining, which is otherwise unknown in nature. Pronounced modifications to immune facilities are associated with this reproductive trait. The genomes of species with temporarily attaching males lack functional aicda genes that underpin affinity maturation of antibodies. Permanent attachment is associated with additional alterations, culminating in the loss of functional rag genes in some species, abolishing somatic diversification of antigen receptor genes, the hallmark of canonical adaptive immunity. In anglerfishes, coevolution of innate and adaptive immunity has been disentangled, implying that an alternative form of immunity supported the emergence of this evolutionarily successful group of vertebrates.
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Affiliation(s)
- Jeremy B Swann
- Department of Developmental Immunology, Max Planck Institute of Immunobiology and Epigenetics, D-79108 Freiburg, Germany.
| | - Stephen J Holland
- Department of Developmental Immunology, Max Planck Institute of Immunobiology and Epigenetics, D-79108 Freiburg, Germany
| | - Malte Petersen
- Department of Developmental Immunology, Max Planck Institute of Immunobiology and Epigenetics, D-79108 Freiburg, Germany
| | - Theodore W Pietsch
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA 98105-5020, USA
| | - Thomas Boehm
- Department of Developmental Immunology, Max Planck Institute of Immunobiology and Epigenetics, D-79108 Freiburg, Germany.
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29
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Oudinet C, Braikia FZ, Dauba A, Khamlichi AA. Mechanism and regulation of class switch recombination by IgH transcriptional control elements. Adv Immunol 2020; 147:89-137. [PMID: 32981636 DOI: 10.1016/bs.ai.2020.06.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Class switch recombination (CSR) plays an important role in humoral immunity by generating antibodies with different effector functions. CSR to a particular antibody isotype is induced by external stimuli, and occurs between highly repetitive switch (S) sequences. CSR requires transcription across S regions, which generates long non-coding RNAs and secondary structures that promote accessibility of S sequences to activation-induced cytidine deaminase (AID). AID initiates DNA double-strand breaks (DSBs) intermediates that are repaired by general DNA repair pathways. Switch transcription is controlled by various regulatory elements, including enhancers and insulators. The current paradigm posits that transcriptional control of CSR involves long-range chromatin interactions between regulatory elements and chromatin loops-stabilizing factors, which promote alignment of partner S regions in a CSR centre (CSRC) and initiation of CSR. In this review, we focus on the role of IgH transcriptional control elements in CSR and the chromatin-based mechanisms underlying this control.
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Affiliation(s)
- Chloé Oudinet
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, Toulouse, France; Institut de Pharmacologie et de Biologie Structurale, CNRS, Université Paul Sabatier, Toulouse, France
| | - Fatima-Zohra Braikia
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, Toulouse, France; Institut de Pharmacologie et de Biologie Structurale, CNRS, Université Paul Sabatier, Toulouse, France
| | - Audrey Dauba
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, Toulouse, France; Institut de Pharmacologie et de Biologie Structurale, CNRS, Université Paul Sabatier, Toulouse, France
| | - Ahmed Amine Khamlichi
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, Toulouse, France; Institut de Pharmacologie et de Biologie Structurale, CNRS, Université Paul Sabatier, Toulouse, France.
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30
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Oudinet C, Braikia FZ, Dauba A, Khamlichi AA. Recombination may occur in the absence of transcription in the immunoglobulin heavy chain recombination centre. Nucleic Acids Res 2020; 48:3553-3566. [PMID: 32086526 PMCID: PMC7144927 DOI: 10.1093/nar/gkaa108] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 02/06/2020] [Accepted: 02/19/2020] [Indexed: 12/18/2022] Open
Abstract
Developing B cells undergo V(D)J recombination to generate a vast repertoire of Ig molecules. V(D)J recombination is initiated by the RAG1/RAG2 complex in recombination centres (RCs), where gene segments become accessible to the complex. Whether transcription is the causal factor of accessibility or whether it is a side product of other processes that generate accessibility remains a controversial issue. At the IgH locus, V(D)J recombination is controlled by Eμ enhancer, which directs the transcriptional, epigenetic and recombinational events in the IgH RC. Deletion of Eμ enhancer affects both transcription and recombination, making it difficult to conclude if Eμ controls the two processes through the same or different mechanisms. By using a mouse line carrying a CpG-rich sequence upstream of Eμ enhancer and analyzing transcription and recombination at the single-cell level, we found that recombination could occur in the RC in the absence of detectable transcription, suggesting that Eμ controls transcription and recombination through distinct mechanisms. Moreover, while the normally Eμ-dependent transcription and demethylating activities were impaired, recruitment of chromatin remodeling complexes was unaffected. RAG1 was efficiently recruited, thus compensating for the defective transcription-associated recruitment of RAG2, and providing a mechanistic basis for RAG1/RAG2 assembly to initiate V(D)J recombination.
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Affiliation(s)
- Chloé Oudinet
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, Université Paul Sabatier, 31077 Toulouse, France
| | - Fatima-Zohra Braikia
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, Université Paul Sabatier, 31077 Toulouse, France
| | - Audrey Dauba
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, Université Paul Sabatier, 31077 Toulouse, France
| | - Ahmed Amine Khamlichi
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, Université Paul Sabatier, 31077 Toulouse, France
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31
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Yen WF, Sharma R, Cols M, Lau CM, Chaudhry A, Chowdhury P, Yewdell WT, Vaidyanathan B, Sun A, Coffre M, Pucella JN, Chen CC, Jasin M, Sun JC, Rudensky AY, Koralov SB, Chaudhuri J. Distinct Requirements of CHD4 during B Cell Development and Antibody Response. Cell Rep 2020; 27:1472-1486.e5. [PMID: 31042474 PMCID: PMC6527137 DOI: 10.1016/j.celrep.2019.04.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 03/15/2019] [Accepted: 04/01/2019] [Indexed: 11/21/2022] Open
Abstract
The immunoglobulin heavy chain (Igh) locus features a dynamic chromatin landscape to promote class switch recombination (CSR), yet the mechanisms that regulate this landscape remain poorly understood. CHD4, a component of the chromatin remodeling NuRD complex, directly binds H3K9me3, an epigenetic mark present at the Igh locus during CSR. We find that CHD4 is essential for early B cell development but is dispensable for the homeostatic maintenance of mature, naive B cells. However, loss of CHD4 in mature B cells impairs CSR because of suboptimal targeting of AID to the Igh locus. Additionally, we find that CHD4 represses p53 expression to promote B cell proliferation. This work reveals distinct roles for CHD4 in B cell development and CSR and links the H3K9me3 epigenetic mark with AID recruitment to the Igh locus. Yen et al. demonstrate that CHD4, a component of the NuRD remodeling complex, is essential for early B cell development, represses p53 expression in mature B cells, and influences the recruitment of AID to DNA during class switch recombination.
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Affiliation(s)
- Wei-Feng Yen
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Biochemistry, Cellular and Molecular Biology Program, Weill Graduate School of Medical Sciences, New York, NY, USA
| | - Rahul Sharma
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Montserrat Cols
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Colleen M Lau
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Ashutosh Chaudhry
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Priyanka Chowdhury
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Immunology and Microbial Pathogenesis Program, Weill Cornell Graduate School of Medical Sciences, New York, NY, USA
| | - William T Yewdell
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Bharat Vaidyanathan
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Immunology and Microbial Pathogenesis Program, Weill Cornell Graduate School of Medical Sciences, New York, NY, USA
| | - Amy Sun
- Department of Pathology, New York University School of Medicine, New York, NY, USA
| | - Maryaline Coffre
- Department of Pathology, New York University School of Medicine, New York, NY, USA
| | - Joseph N Pucella
- Gerstner Sloan Kettering Graduate School of Biomedical Sciences, New York, NY, USA
| | - Chun-Chin Chen
- Biochemistry, Cellular and Molecular Biology Program, Weill Graduate School of Medical Sciences, New York, NY, USA; Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Maria Jasin
- Biochemistry, Cellular and Molecular Biology Program, Weill Graduate School of Medical Sciences, New York, NY, USA; Gerstner Sloan Kettering Graduate School of Biomedical Sciences, New York, NY, USA; Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Joseph C Sun
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Immunology and Microbial Pathogenesis Program, Weill Cornell Graduate School of Medical Sciences, New York, NY, USA; Gerstner Sloan Kettering Graduate School of Biomedical Sciences, New York, NY, USA
| | - Alexander Y Rudensky
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Immunology and Microbial Pathogenesis Program, Weill Cornell Graduate School of Medical Sciences, New York, NY, USA; Gerstner Sloan Kettering Graduate School of Biomedical Sciences, New York, NY, USA; Howard Hughes Medical Institute, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Sergei B Koralov
- Department of Pathology, New York University School of Medicine, New York, NY, USA
| | - Jayanta Chaudhuri
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Immunology and Microbial Pathogenesis Program, Weill Cornell Graduate School of Medical Sciences, New York, NY, USA; Gerstner Sloan Kettering Graduate School of Biomedical Sciences, New York, NY, USA.
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32
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Wang XS, Lee BJ, Zha S. The recent advances in non-homologous end-joining through the lens of lymphocyte development. DNA Repair (Amst) 2020; 94:102874. [PMID: 32623318 DOI: 10.1016/j.dnarep.2020.102874] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/16/2020] [Accepted: 05/24/2020] [Indexed: 12/17/2022]
Abstract
Lymphocyte development requires ordered assembly and subsequent modifications of the antigen receptor genes through V(D)J recombination and Immunoglobulin class switch recombination (CSR), respectively. While the programmed DNA cleavage events are initiated by lymphocyte-specific factors, the resulting DNA double-strand break (DSB) intermediates activate the ATM kinase-mediated DNA damage response (DDR) and rely on the ubiquitously expressed classical non-homologous end-joining (cNHEJ) pathway including the DNA-dependent protein kinase (DNA-PK), and, in the case of CSR, also the alternative end-joining (Alt-EJ) pathway, for repair. Correspondingly, patients and animal models with cNHEJ or DDR defects develop distinct types of immunodeficiency reflecting their specific DNA repair deficiency. The unique end-structure, sequence context, and cell cycle regulation of V(D)J recombination and CSR also provide a valuable platform to study the mechanisms of, and the interplay between, cNHEJ and DDR. Here, we compare and contrast the genetic consequences of DNA repair defects in V(D)J recombination and CSR with a focus on the newly discovered cNHEJ factors and the kinase-dependent structural roles of ATM and DNA-PK in animal models. Throughout, we try to highlight the pending questions and emerging differences that will extend our understanding of cNHEJ and DDR in the context of primary immunodeficiency and lymphoid malignancies.
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Affiliation(s)
- Xiaobin S Wang
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States; Graduate Program of Pathobiology and Molecular Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States
| | - Brian J Lee
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States
| | - Shan Zha
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States; Department of Pediatrics, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States; Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States; Department of Immunology and Microbiology, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States.
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33
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Tsakou-Ngouafo L, Paganini J, Kaufman J, Pontarotti P. Origins of the RAG Transposome and the MHC. Trends Immunol 2020; 41:561-571. [PMID: 32467030 DOI: 10.1016/j.it.2020.05.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 05/04/2020] [Accepted: 05/06/2020] [Indexed: 01/12/2023]
Abstract
How innate immunity gave rise to adaptive immunity in vertebrates remains unknown. We propose an evolutionary scenario beginning with pathogen-associated molecular pattern(s) (PAMPs) being presented by molecule(s) on one cell to specific receptor(s) on other cells, much like MHC molecules and T cell receptors (TCRs). In this model, mutations in MHC-like molecule(s) that bound new PAMP(s) would not be recognized by original TCR-like molecule(s), and new MHC-like gene(s) would be lost by neutral drift. Integrating recombination activating gene (RAG) transposon(s) in a TCR-like gene would result in greater recognition diversity, with new MHC-like variants recognized and selected, along with a new RAG/TCR-like system. MHC genes would be selected to present many peptides, through multigene families, allelic polymorphism, and peptide-binding promiscuity.
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Affiliation(s)
- Louis Tsakou-Ngouafo
- Aix Marseille University IRD, APHM, MEPHI, IHU Méditerranée Infection, Marseille France 3, 19-21 Boulevard Jean Moulin, 13005 Marseille, France
| | | | - Jim Kaufman
- University of Cambridge, Department of Pathology, Tennis Court Road, Cambridge CB2 1QP, UK; University of Cambridge, Department of Veterinary Medicine, Madingley Road, Cambridge CB2 0ES, UK; University of Edinburgh, Institute for Immunology and Infection Research, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK.
| | - Pierre Pontarotti
- Aix Marseille University IRD, APHM, MEPHI, IHU Méditerranée Infection, Marseille France 3, 19-21 Boulevard Jean Moulin, 13005 Marseille, France; SNC5039 CNRS, 19-21 Boulevard Jean Moulin, 13005 Marseilles, France.
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34
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Sun A, Xu K, Liu H, Li H, Shi Y, Zhu X, Liang T, Li X, Cao X, Ji Y, Jiang T, Xu C, Liu X. The evolution of zebrafish RAG2 protein is required for adapting to the elevated body temperature of the higher endothermic vertebrates. Sci Rep 2020; 10:4126. [PMID: 32139788 PMCID: PMC7057966 DOI: 10.1038/s41598-020-61019-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 02/19/2020] [Indexed: 11/21/2022] Open
Abstract
The recombination activating gene (RAG or RAG1/RAG2 complex)-mediated adaptive immune system is a hallmark of jawed vertebrates. It has been reported that RAG originated in invertebrates. However, whether RAG further evolved once it arose in jawed vertebrates remains largely unknown. Here, we found that zebrafish RAG (zRAG) had a lower activity than mouse RAG (mRAG). Intriguingly, the attenuated stability of zebrafish RAG2 (zRAG2), but not zebrafish RAG1, caused the reduced V(D)J recombination efficiency compared to mRAG at 37 °C which are the body temperature of most endotherms except birds. Importantly, the lower temperature 28 °C, which is the best temperature for zebrafish growth, made the recombination efficiency of zRAG similar to that of mRAG by improving the stability of zRAG2. Consistent with the prementioned observation, the V(D)J recombination of Rag2KI/KI mice, which zRAG2 was substituted for mRAG2, was also severely impaired. Unexpectedly, Rag2KI/KI mice developed cachexia syndromes accompanied by premature death. Taken together, our findings illustrate that the evolution of zebrafish RAG2 protein is required for adapting to the elevated body temperature of the higher endothermic vertebrates.
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Affiliation(s)
- Ao Sun
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200031, China
| | - Ke Xu
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200031, China
| | - Haifeng Liu
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200031, China
| | - Hua Li
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200031, China
| | - Yaohuang Shi
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200031, China.,School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Xiaoyan Zhu
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200031, China
| | - Tao Liang
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200031, China
| | - Xinyue Li
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200031, China
| | - Xianxia Cao
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200031, China.,School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Yanhong Ji
- Department of Pathogenic Biology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Centre, Xi'an, Shaanxi, 710061, China
| | - Taijiao Jiang
- Center of System Medicine, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100005, China
| | - Chenqi Xu
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200031, China
| | - Xiaolong Liu
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200031, China. .,School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
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Chi X, Li Y, Qiu X. V(D)J recombination, somatic hypermutation and class switch recombination of immunoglobulins: mechanism and regulation. Immunology 2020; 160:233-247. [PMID: 32031242 DOI: 10.1111/imm.13176] [Citation(s) in RCA: 116] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Revised: 12/30/2019] [Accepted: 01/08/2020] [Indexed: 02/06/2023] Open
Abstract
Immunoglobulins emerging from B lymphocytes and capable of recognizing almost all kinds of antigens owing to the extreme diversity of their antigen-binding portions, known as variable (V) regions, play an important role in immune responses. The exons encoding the V regions are known as V (variable), D (diversity), or J (joining) genes. V, D, J segments exist as multiple copy arrays on the chromosome. The recombination of the V(D)J gene is the key mechanism to produce antibody diversity. The recombinational process, including randomly choosing a pair of V, D, J segments, introducing double-strand breaks adjacent to each segment, deleting (or inverting in some cases) the intervening DNA and ligating the segments together, is defined as V(D)J recombination, which contributes to surprising immunoglobulin diversity in vertebrate immune systems. To enhance both the ability of immunoglobulins to recognize and bind to foreign antigens and the effector capacities of the expressed antibodies, naive B cells will undergo class switching recombination (CSR) and somatic hypermutation (SHM). However, the genetics mechanisms of V(D)J recombination, CSR and SHM are not clear. In this review, we summarize the major progress in mechanism studies of immunoglobulin V(D)J gene recombination and CSR as well as SHM, and their regulatory mechanisms.
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Affiliation(s)
- Xiying Chi
- Department of Immunology, School of Basic Medical Sciences, Peking University, Beijing, China.,NHC Key Laboratory of Medical Immunology, Peking University, Beijing, China
| | - Yue Li
- Department of Immunology, School of Basic Medical Sciences, Peking University, Beijing, China.,NHC Key Laboratory of Medical Immunology, Peking University, Beijing, China
| | - Xiaoyan Qiu
- Department of Immunology, School of Basic Medical Sciences, Peking University, Beijing, China.,NHC Key Laboratory of Medical Immunology, Peking University, Beijing, China
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36
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Analyses of RAG1 and RAG2 genes suggest different evolutionary rates in the Cetacea lineage. Mol Immunol 2019; 117:131-138. [PMID: 31770676 DOI: 10.1016/j.molimm.2019.10.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 10/14/2019] [Accepted: 10/23/2019] [Indexed: 01/01/2023]
Abstract
V(D)J recombination is a process of somatic recombination catalyzed by proteins encoded by RAG1 and RAG2 genes, both restricted to the genome of jawed vertebrates. Their proteins constitute the enzymatic core of V(D)J recombination machinery and are crucial for jawed vertebrate adaptive immunity. Mammals possess great ecological diversity, and their complex evolutionary history associated with radiation to different environments presented many distinct pathogenic challenges from these different habitats. Cetaceans comprise a mammalian order of fully aquatic mammals that have arisen from a complete terrestrial ancestor and, accordingly, was confronted with challenges from changing environmental pathogens while they transitioned from land to sea. In this study we undertook molecular evolutionary analyses of RAG1 and RAG2 genes, exploring the possible role of natural selection acting on these genes focusing on the cetacean lineage. We performed phylogenetic reconstructions on IQ-TREE, together with selection analyses in the codeml program of the PAML package, and in the FITMODEL program for codon evolution and switching on both the RAG1 and RAG2 genes. Our findings demonstrate that RAG1 and RAG2 remained fairly conserved among tetrapods, with purifying selection acting on both genes, with evidence for a few punctuated shifts in nucleotide substitution rates of both genes along tetrapod evolution. We demonstrate differential evolution in the closely linked genes RAG1 and RAG2 specifically in cetaceans.
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37
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Type II DNA Topoisomerases Cause Spontaneous Double-Strand Breaks in Genomic DNA. Genes (Basel) 2019; 10:genes10110868. [PMID: 31671674 PMCID: PMC6895833 DOI: 10.3390/genes10110868] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/22/2019] [Accepted: 10/26/2019] [Indexed: 12/31/2022] Open
Abstract
Type II DNA topoisomerase enzymes (TOP2) catalyze topological changes by strand passage reactions. They involve passing one intact double stranded DNA duplex through a transient enzyme-bridged break in another (gated helix) followed by ligation of the break by TOP2. A TOP2 poison, etoposide blocks TOP2 catalysis at the ligation step of the enzyme-bridged break, increasing the number of stable TOP2 cleavage complexes (TOP2ccs). Remarkably, such pathological TOP2ccs are formed during the normal cell cycle as well as in postmitotic cells. Thus, this ‘abortive catalysis’ can be a major source of spontaneously arising DNA double-strand breaks (DSBs). TOP2-mediated DSBs are also formed upon stimulation with physiological concentrations of androgens and estrogens. The frequent occurrence of TOP2-mediated DSBs was previously not appreciated because they are efficiently repaired. This repair is performed in collaboration with BRCA1, BRCA2, MRE11 nuclease, and tyrosyl-DNA phosphodiesterase 2 (TDP2) with nonhomologous end joining (NHEJ) factors. This review first discusses spontaneously arising DSBs caused by the abortive catalysis of TOP2 and then summarizes proteins involved in repairing stalled TOP2ccs and discusses the genotoxicity of the sex hormones.
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38
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Zhang Y, Zhang X, Ba Z, Liang Z, Dring EW, Hu H, Lou J, Kyritsis N, Zurita J, Shamim MS, Presser Aiden A, Lieberman Aiden E, Alt FW. The fundamental role of chromatin loop extrusion in physiological V(D)J recombination. Nature 2019; 573:600-604. [PMID: 31511698 PMCID: PMC6867615 DOI: 10.1038/s41586-019-1547-y] [Citation(s) in RCA: 96] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 08/12/2019] [Indexed: 11/24/2022]
Abstract
RAG endonuclease initiates IgH locus (Igh) V(D)J assembly in progenitor (pro)-B cells by joining Ds to JHs, before joining upstream VHs to DJH intermediates1. In mouse pro-B cells, the CTCF-binding element (CBE)-anchored chromatin loop domain2 at the 3’end of Igh contains an internal sub-domain spanning the 5’CBE anchor (IGCR1)3, the DHs, and a RAG-bound recombination center (RC)4. The RC comprises JH-proximal D (DQ52), 4 JHs, and the intronic enhancer (“iEμ”)5. Robust RAG cleavage is restricted to paired V(D)J segments flanked by complementary recombination signal sequences (12RSSs and 23RSSs)6. Ds are flanked downstream and upstream by 12RSSs that, respectively, mediate deletional joining with convergently-oriented JH-23RSSs and VH-23RSSs6. Despite 12/23 compatibility, inversional D to JH joining via upstream D-12RSSs is rare7,8. Plasmid-based assays attributed lack of inversional D to JH joining to sequence-based preference for downstream D-12RSSs9, as opposed to putative linear scanning mechanisms10,11. Given recent findings that RAG linearly scans convergent CBE-anchored chromatin loops4,12-14, potentially formed by cohesin-mediated loop extrusion15-18, we revisited a scanning role. Here, we report that JH-23RSS chromosomal orientation programs RC-bound RAG to linearly scan upstream chromatin in the 3’Igh sub-domain for convergently-oriented D-12RSSs and, thereby, to mediate deletional joining of all Ds, except RC-based DQ52 that joins by a diffusion-related mechanism. In a DQ52-based RC, formed in the absence of JHs, RAG bound by the downstream DQ52-RSS scans the downstream constant region exon-containing 3’Igh sub-domain in which scanning can be impeded by targeted nuclease-dead Cas9 (dCas9) binding, by transcription through repetitive Igh switch sequences, and by the 3’Igh CBE-based loop anchor. Notably, each scanning impediment focally increases RAG activity on potential substrate sequences within the impeded region. High resolution mapping of RC chromatin interactions reveals that such focal RAG targeting is associated with corresponding impediments to the loop extrusion process that drives chromatin past RC-bound RAG.
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Affiliation(s)
- Yu Zhang
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA.,Howard Hughes Medical Institute, Boston, MA, USA.,Center for Immunobiology, Department of Biomedical Sciences, Western Michigan University Homer Stryker M.D. School of Medicine, Kalamazoo, MI, USA.,Center for Immunobiology, Department of Biomedical Sciences, Western Michigan University Homer Stryker M.D. School of Medicine, Kalamazoo, MI, USA
| | - Xuefei Zhang
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA.,Howard Hughes Medical Institute, Boston, MA, USA
| | - Zhaoqing Ba
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA.,Howard Hughes Medical Institute, Boston, MA, USA
| | - Zhuoyi Liang
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA.,Howard Hughes Medical Institute, Boston, MA, USA
| | - Edward W Dring
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA.,Howard Hughes Medical Institute, Boston, MA, USA
| | - Hongli Hu
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA.,Howard Hughes Medical Institute, Boston, MA, USA
| | - Jiangman Lou
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA.,Howard Hughes Medical Institute, Boston, MA, USA
| | - Nia Kyritsis
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA.,Howard Hughes Medical Institute, Boston, MA, USA
| | - Jeffrey Zurita
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA.,Howard Hughes Medical Institute, Boston, MA, USA
| | - Muhammad S Shamim
- The Center for Genome Architecture, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,Department of Bioengineering, Rice University, Houston, TX, USA.,Department of Computer Science, Rice University, Houston, TX, USA.,Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, USA
| | - Aviva Presser Aiden
- The Center for Genome Architecture, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,Department of Bioengineering, Rice University, Houston, TX, USA.,Department of Pediatrics, Texas Children's Hospital, Houston, TX, USA
| | - Erez Lieberman Aiden
- The Center for Genome Architecture, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,Department of Computer Science, Rice University, Houston, TX, USA.,Center for Theoretical Biological Physics, Rice University, Houston, TX, USA.,Broad Institute of MIT and Harvard, Cambridge, MA, USA.,Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China
| | - Frederick W Alt
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA. .,Department of Genetics, Harvard Medical School, Boston, MA, USA. .,Howard Hughes Medical Institute, Boston, MA, USA.
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39
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Nbn-Mre11 interaction is required for tumor suppression and genomic integrity. Proc Natl Acad Sci U S A 2019; 116:15178-15183. [PMID: 31285322 DOI: 10.1073/pnas.1905305116] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
We derived a mouse model in which a mutant form of Nbn/Nbs1mid8 (hereafter Nbnmid8) exhibits severely impaired binding to the Mre11-Rad50 core of the Mre11 complex. The Nbn mid8 allele was expressed exclusively in hematopoietic lineages (in Nbn -/mid8vav mice). Unlike Nbn flox/floxvav mice with Nbn deficiency in the bone marrow, Nbn -/mid8vav mice were viable. Nbn -/mid8vav mice hematopoiesis was profoundly defective, exhibiting reduced cellularity of thymus and bone marrow, and stage-specific blockage of B cell development. Within 6 mo, Nbn -/mid8 mice developed highly penetrant T cell leukemias. Nbn -/mid8vav leukemias recapitulated mutational features of human T cell acute lymphoblastic leukemia (T-ALL), containing mutations in NOTCH1, TP53, BCL6, BCOR, and IKZF1, suggesting that Nbn mid8 mice may provide a venue to examine the relationship between the Mre11 complex and oncogene activation in the hematopoietic compartment. Genomic analysis of Nbn -/mid8vav malignancies showed focal amplification of 9qA2, causing overexpression of MRE11 and CHK1 We propose that overexpression of MRE11 compensates for the metastable Mre11-Nbnmid8 interaction, and that selective pressure for overexpression reflects the essential role of Nbn in promoting assembly and activity of the Mre11 complex.
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40
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Lapp HE, Hunter RG. Early life exposures, neurodevelopmental disorders, and transposable elements. Neurobiol Stress 2019; 11:100174. [PMID: 31193573 PMCID: PMC6536887 DOI: 10.1016/j.ynstr.2019.100174] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 03/27/2019] [Accepted: 05/21/2019] [Indexed: 12/26/2022] Open
Abstract
Transposable elements make up a much larger portion of the genome than protein-coding genes, yet we know relatively little about their function in the human genome. However, we are beginning to more fully understand their role in brain development, neuroinflammation, and adaptation to environmental insults such as stress. For instance, glucocorticoid receptor activation regulates transposable elements in the brain following acute stress. Early life is a period of substantial brain development during which transposable elements play a role. Environmental exposures and experiences during early life that promote abnormal regulation of transposable elements may lead to a cascade of events that ultimately increase susceptibility to disorders later in life. Recent attention to transposable elements in psychiatric illness has begun to clarify associations indicative of dysregulation of different classes of transposable elements in stress-related and neurodevelopmental illness. Though individual susceptibility or resiliency to psychiatric illness has not been explained by traditional genetic studies, the wide inter-individual variability in transposable element composition in the human genome make TEs attractive candidates to elucidate this differential susceptibility. In this review, we discuss evidence that regulation of transposable elements in the brain are stage-specific, sensitive to environmental factors, and may be impacted by early life perturbations. We further present evidence of associations with stress-related and neurodevelopmental psychiatric illness from a developmental perspective.
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Affiliation(s)
- Hannah E Lapp
- University of Massachusetts Boston, 100 Morrissey Blvd Boston, MA, 02125, USA
| | - Richard G Hunter
- University of Massachusetts Boston, 100 Morrissey Blvd Boston, MA, 02125, USA
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41
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Rodgers W, Byrum JN, Simpson DA, Hoolehan W, Rodgers KK. RAG2 localization and dynamics in the pre-B cell nucleus. PLoS One 2019; 14:e0216137. [PMID: 31075127 PMCID: PMC6510410 DOI: 10.1371/journal.pone.0216137] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 04/16/2019] [Indexed: 12/31/2022] Open
Abstract
RAG2 of the V(D)J recombinase is essential for lymphocyte development. Within the RAG2 noncore region is a plant homeodomain (PHD) that interacts with the modified histone H3K4me3, and this interaction is important for relieving inhibition of the RAG recombinase for V(D)J recombination. However, the effect of the noncore region on RAG2 localization and dynamics in cell nuclei is poorly understood. Here, we used cell imaging to measure the effect of mutating the RAG2 noncore region on properties of the full length protein. We measured GFP-labeled full length RAG2 (FL), the RAG2 core region alone (Core), and a T490A mutant in the noncore region, which has unique regulatory properties. This showed that FL, T490A, and Core localized to nuclear domains that were adjacent to DAPI-rich heterochromatin, and that contained the active chromatin marker H3K4me3. Within the RAG2-enriched regions, T490A exhibited greater colocalization with H3K4me3 than either FL or Core. Furthermore, colocalization of H3K4me3 with FL and T490A, but not Core, increased in conditions that increased H3K4me3 levels. Superresolution imaging showed H3K4me3 was distributed as puncta that RAG2 abutted, and mobility measurements showed that T490A had a significantly lower rate of diffusion within the nucleus than either FL or Core proteins. Finally, mutating Trp453 of the T490A mutant (W453A,T490A), which blocks PHD-dependent interactions with H3K4me3, abolished the T490A-mediated increased colocalization with H3K4me3 and slower mobility compared to FL. Altogether, these data show that Thr490 in the noncore region modulates RAG2 localization and dynamics in the pre-B cell nucleus, such as by affecting RAG2 interactions with H3K4me3.
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Affiliation(s)
- William Rodgers
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma, United States of America
| | - Jennifer N. Byrum
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Destiny A. Simpson
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Walker Hoolehan
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Karla K. Rodgers
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
- * E-mail:
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42
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Abstract
Vast repertoires of unique antigen receptors are created in developing lymphocytes. The antigen receptor loci contain many variable (V), diversity (D), and joining (J) gene segments that are arrayed across very large genomic expanses and are joined to form variable-region exons. This process creates the potential for an organism to respond to large numbers of different pathogens. Here, we consider the underlying molecular mechanisms that favor some V genes for recombination prior to selection of the final antigen receptor repertoire. We discuss chromatin structures that form in antigen receptor loci to permit spatial proximity among the V, D, and J gene segments and how these relate to the generation of antigen receptor diversity.
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Affiliation(s)
- Amy L Kenter
- Department of Microbiology and Immunology, University of Illinois College of Medicine, Chicago, IL, 60612-7344, USA
| | - Ann J Feeney
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, 92037, USA
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43
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Villa A, Notarangelo LD. RAG gene defects at the verge of immunodeficiency and immune dysregulation. Immunol Rev 2019; 287:73-90. [PMID: 30565244 PMCID: PMC6309314 DOI: 10.1111/imr.12713] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 08/21/2018] [Indexed: 12/18/2022]
Abstract
Mutations of the recombinase activating genes (RAG) in humans underlie a broad spectrum of clinical and immunological phenotypes that reflect different degrees of impairment of T- and B-cell development and alterations of mechanisms of central and peripheral tolerance. Recent studies have shown that this phenotypic heterogeneity correlates, albeit imperfectly, with different levels of recombination activity of the mutant RAG proteins. Furthermore, studies in patients and in newly developed animal models carrying hypomorphic RAG mutations have disclosed various mechanisms underlying immune dysregulation in this condition. Careful annotation of clinical outcome and immune reconstitution in RAG-deficient patients who have received hematopoietic stem cell transplantation has shown that progress has been made in the treatment of this disease, but new approaches remain to be tested to improve stem cell engraftment and durable immune reconstitution. Finally, initial attempts have been made to treat RAG deficiency with gene therapy.
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Affiliation(s)
- Anna Villa
- San Raffaele Telethon Institute for Gene Therapy (SR-TIGET), Division of Regenerative Medicine, Stem Cell and Gene Therapy, San Raffaele Scientific Institute, Milan, Italy
- Milan Unit, Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, Milan, Italy
| | - Luigi D Notarangelo
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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Lin SG, Ba Z, Alt FW, Zhang Y. RAG Chromatin Scanning During V(D)J Recombination and Chromatin Loop Extrusion are Related Processes. Adv Immunol 2018; 139:93-135. [PMID: 30249335 DOI: 10.1016/bs.ai.2018.07.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
An effective adaptive immune system depends on the ability of developing B and T cells to generate diverse immunoglobulin (Ig) and T cell receptor repertoires, respectively. Such diversity is achieved through a programmed somatic recombination process whereby germline V, D, and J segments of antigen receptor loci are assembled to form the variable region V(D)J exons of Ig and TCRs. Studies of this process, termed V(D)J recombination, have provided key insights into our understanding of a variety of general gene regulatory and DNA repair processes over the last several decades. V(D)J recombination is initiated by the RAG endonuclease which generates DNA double-stranded breaks at the borders of V, D, and J segments. In this review, we cover recent work that has elucidated RAG structure and work that revealed that RAG has a novel chromatin scanning activity, likely mediated by chromatin loop extrusion, that contributes to its ability to locate V, D, J gene segment substrates within large chromosomal loop domains bounded by CTCF-binding elements (CBEs). This latter function, coupled with the role CBE-based chromatin loop domains and subdomains within them play in focusing V(D)J recombination activity within antigen receptor loci, provide mechanistic explanations for long-standing questions regarding V(D)J segment usage diversification and in limiting potentially deleterious off-target RAG-initiated recombination events genome-wide. This review will focus mainly on studies of the mouse Ig heavy chain locus, but the principles described also apply to other Ig loci and to TCR loci in mice and humans.
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Affiliation(s)
- Sherry G Lin
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, and Department of Genetics, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, United States
| | - Zhaoqing Ba
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, and Department of Genetics, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, United States
| | - Frederick W Alt
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, and Department of Genetics, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, United States.
| | - Yu Zhang
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, and Department of Genetics, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, United States
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Jain S, Ba Z, Zhang Y, Dai HQ, Alt FW. CTCF-Binding Elements Mediate Accessibility of RAG Substrates During Chromatin Scanning. Cell 2018; 174:102-116.e14. [PMID: 29804837 PMCID: PMC6026039 DOI: 10.1016/j.cell.2018.04.035] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 04/07/2018] [Accepted: 04/25/2018] [Indexed: 01/06/2023]
Abstract
RAG endonuclease initiates antibody heavy chain variable region exon assembly from V, D, and J segments within a chromosomal V(D)J recombination center (RC) by cleaving between paired gene segments and flanking recombination signal sequences (RSSs). The IGCR1 control region promotes DJH intermediate formation by isolating Ds, JHs, and RCs from upstream VHs in a chromatin loop anchored by CTCF-binding elements (CBEs). How VHs access the DJHRC for VH to DJH rearrangement was unknown. We report that CBEs immediately downstream of frequently rearranged VH-RSSs increase recombination potential of their associated VH far beyond that provided by RSSs alone. This CBE activity becomes particularly striking upon IGCR1 inactivation, which allows RAG, likely via loop extrusion, to linearly scan chromatin far upstream. VH-associated CBEs stabilize interactions of D-proximal VHs first encountered by the DJHRC during linear RAG scanning and thereby promote dominant rearrangement of these VHs by an unanticipated chromatin accessibility-enhancing CBE function.
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MESH Headings
- Animals
- CCCTC-Binding Factor/metabolism
- Cell Line
- Chromatin/metabolism
- DNA, Intergenic/genetics
- DNA, Intergenic/metabolism
- DNA-Binding Proteins/deficiency
- DNA-Binding Proteins/genetics
- Homeodomain Proteins/metabolism
- Immunoglobulin Heavy Chains/genetics
- Immunoglobulin Heavy Chains/metabolism
- Immunoglobulin Variable Region/genetics
- Immunoglobulin Variable Region/metabolism
- Mice
- Mice, Inbred C57BL
- Models, Molecular
- Mutagenesis
- Protein Sorting Signals
- Receptors, Antigen, T-Cell/genetics
- Receptors, Antigen, T-Cell/metabolism
- V(D)J Recombination
- RNA, Guide, CRISPR-Cas Systems
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Affiliation(s)
- Suvi Jain
- Howard Hughes Medical Institute; Program in Cellular and Molecular Medicine, Boston Children's Hospital, and Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Zhaoqing Ba
- Howard Hughes Medical Institute; Program in Cellular and Molecular Medicine, Boston Children's Hospital, and Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Yu Zhang
- Howard Hughes Medical Institute; Program in Cellular and Molecular Medicine, Boston Children's Hospital, and Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Hai-Qiang Dai
- Howard Hughes Medical Institute; Program in Cellular and Molecular Medicine, Boston Children's Hospital, and Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Frederick W Alt
- Howard Hughes Medical Institute; Program in Cellular and Molecular Medicine, Boston Children's Hospital, and Department of Genetics, Harvard Medical School, Boston, MA 02115, USA.
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46
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Hypomorphic Rag1 mutations alter the preimmune repertoire at early stages of lymphoid development. Blood 2018; 132:281-292. [PMID: 29743177 DOI: 10.1182/blood-2017-12-820985] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2017] [Accepted: 04/30/2018] [Indexed: 12/13/2022] Open
Abstract
Hypomorphic RAG1 mutations allowing residual T- and B-cell development have been found in patients presenting with delayed-onset combined immune deficiency with granulomas and/or autoimmunity (CID-G/AI) and abnormalities of the peripheral T- and B-cell repertoire. To examine how hypomorphic Rag1 mutations affect the earliest stages of lymphocyte development, we used CRISPR/Cas9 to generate mouse models with mutations equivalent to those found in patients with CID-G/AI. Immunological characterization showed partial development of T and B lymphocytes, with persistence of naïve cells and preserved serum immunoglobulin but impaired antibody responses and presence of autoantibodies, thereby recapitulating the phenotype seen in patients with CID-G/AI. By using high-throughput sequencing, we identified marked skewing of Igh V and Trb V gene usage in early progenitors, with a bias for productive Igh and Trb rearrangements after selection occurred and increased apoptosis of B-cell progenitors. Rearrangement at the Igk locus was impaired, and polyreactive immunoglobulin M antibodies were detected. This study provides novel insights into how hypomorphic Rag1 mutations alter the primary repertoire of T and B cells, setting the stage for immune dysregulation frequently seen in patients.
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Iarovaia OV, Ioudinkova ES, Razin SV, Vassetzky YS. Role of the Nucleolus in Rearrangements of the IGH Locus. Mol Biol 2018. [DOI: 10.1134/s0026893317050211] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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48
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Dubois E, Mathy N, Régnier V, Bischerour J, Baudry C, Trouslard R, Bétermier M. Multimerization properties of PiggyMac, a domesticated piggyBac transposase involved in programmed genome rearrangements. Nucleic Acids Res 2017; 45:3204-3216. [PMID: 28104713 PMCID: PMC5389696 DOI: 10.1093/nar/gkw1359] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 12/28/2016] [Indexed: 02/05/2023] Open
Abstract
During sexual processes, the ciliate Paramecium eliminates 25–30% of germline DNA from its somatic genome. DNA elimination includes excision of ∼45 000 short, single-copy internal eliminated sequences (IESs) and depends upon PiggyMac (Pgm), a domesticated piggyBac transposase that is essential for DNA cleavage at IES ends. Pgm carries a core transposase region with a putative catalytic domain containing three conserved aspartic acids, and a downstream cysteine-rich (CR) domain. A C-terminal extension of unknown function is predicted to adopt a coiled-coil (CC) structure. To address the role of the three domains, we designed an in vivo complementation assay by expressing wild-type or mutant Pgm-GFP fusions in cells depleted for their endogenous Pgm. The DDD triad and the CR domain are essential for Pgm activity and mutations in either domain have a dominant-negative effect in wild-type cells. A mutant lacking the CC domain is partially active in the presence of limiting Pgm amounts, but inactive when Pgm is completely absent, suggesting that presence of the mutant protein increases the overall number of active complexes. We conclude that IES excision involves multiple Pgm subunits, of which at least a fraction must contain the CC domain.
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Affiliation(s)
- Emeline Dubois
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Nathalie Mathy
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Vinciane Régnier
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France.,Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Julien Bischerour
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Céline Baudry
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Raphaëlle Trouslard
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Mireille Bétermier
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
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Abstract
OPINION STATEMENT Cutaneous T cell lymphomas (CTCLs) are non-Hodgkin lymphomas of skin homing T cells. Although early-stage disease may be limited to the skin, tumor cells in later stage disease can populate the blood, the lymph nodes, and the visceral organs. Unfortunately, there are few molecular biomarkers to guide diagnosis, staging, or treatment of CTCL. Diagnosis of CTCL can be challenging and requires the synthesis of clinical findings, histopathology, and T cell clonality studies; however, none of these tests are entirely sensitive or specific for CTCL. Treatment of CTCL is often empiric and is not typically based on specific molecular alterations, as is common in other cancers. In part, limitations in diagnosis and treatment selection reflect the limited insight into the genetic basis of CTCL. Recent next-generation sequencing has revolutionized our understanding of the mutational landscape in this disease. These analyses have uncovered ultraviolet radiation and recombination activating gene (RAG) endonucleases as important mutagens. Furthermore, these studies have revealed potentially targetable oncogenic mutations in the T cell receptor complex, NF-κB, and JAK-STAT signaling pathways. Collectively, these somatic mutations drive lymphomagenesis via cancer-promoting changes in proliferation, apoptosis, and T cell effector function. We expect that these genetic findings will launch a new era of precision medicine in CTCL.
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50
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Dong Y, Wu C, Zhao X, Zhang P, Zhang H, Zheng M, Li S, Jiao J, Yu X, Lv Z, Ji Y. Epigenetic modifications of the V H region after DJ H recombination in Pro-B cells. Immunology 2017; 152:218-231. [PMID: 28502113 DOI: 10.1111/imm.12758] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Revised: 04/27/2017] [Accepted: 05/08/2017] [Indexed: 12/19/2022] Open
Abstract
The variable region of murine immunoglobulin heavy chain (Igh) is assembled by sequential DH -JH and VH -DJH recombination. The accessibility of the Igh locus determines the order of rearrangement. Because of the large number of VH genes and the lack of a suitable model, the epigenetic modifications of VH genes after DJH recombination have not previously been characterized. Here, we employed two v-Abl pro-B cell lines, in which the Igh locus is in germline and DJH -recombined configurations, respectively. The DJH junction displays the characteristics of a recombination centre, such as high levels of activation-associated histone modifications and recombination-activating gene protein (RAG) binding in DJH -rearranged pro-B cells, which extend the recombination centre model proposed for the germline Igh locus. The different domains of the VH region have distinct epigenetic characteristics after DJH recombination. Distal VH genes have higher levels of active histone modifications, germline transcription and Pax5 binding, and good quality recombination signal sequences. Proximal VH genes are relatively close to the DJH recombination centre, which partially compensates for the low levels of the above active epigenetic modifications. DJH recombination centre might serve as a cis-acting element to regulate the accessibility of the VH region. Furthermore, we demonstrate that RAG weakly binds to functional VH genes, which is the first detailed assessment of RAG dynamic binding to VH genes. We provide a way for VH -DJH recombination in which the VH gene is brought into close proximity with the DJH recombination centre for RAG binding by a Pax5-dependent chromosomal compaction event, and held in this position for subsequent cleavage and VH -DJH joining.
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Affiliation(s)
- Yanying Dong
- Department of Pathogenic Biology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Centre, Xi'an, Shaanxi, China.,Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education of China, Xi'an, Shaanxi, China
| | - Caijun Wu
- Department of Pathogenic Biology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Centre, Xi'an, Shaanxi, China.,Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education of China, Xi'an, Shaanxi, China
| | - Xiaohui Zhao
- Department of Pathogenic Biology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Centre, Xi'an, Shaanxi, China.,Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education of China, Xi'an, Shaanxi, China
| | - Ping Zhang
- Department of Pathogenic Biology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Centre, Xi'an, Shaanxi, China.,Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education of China, Xi'an, Shaanxi, China
| | - Hua Zhang
- Department of Pathogenic Biology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Centre, Xi'an, Shaanxi, China.,Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education of China, Xi'an, Shaanxi, China
| | - Mingzhe Zheng
- Department of Pathogenic Biology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Centre, Xi'an, Shaanxi, China.,Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education of China, Xi'an, Shaanxi, China
| | - Shichang Li
- Department of Pathogenic Biology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Centre, Xi'an, Shaanxi, China.,Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education of China, Xi'an, Shaanxi, China
| | - Junna Jiao
- Department of Pathogenic Biology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Centre, Xi'an, Shaanxi, China.,Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education of China, Xi'an, Shaanxi, China
| | - Xiaozhuo Yu
- Department of Pathogenic Biology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Centre, Xi'an, Shaanxi, China.,Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education of China, Xi'an, Shaanxi, China
| | - Zhuangwei Lv
- Department of Pathogenic Biology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Centre, Xi'an, Shaanxi, China.,Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education of China, Xi'an, Shaanxi, China
| | - Yanhong Ji
- Department of Pathogenic Biology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Centre, Xi'an, Shaanxi, China.,Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education of China, Xi'an, Shaanxi, China
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