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Sharma S, Dasgupta M, Vadaga BS, Kodgire P. Unfolding the symbiosis of AID, chromatin remodelers, and epigenetics-The ACE phenomenon of antibody diversity. Immunol Lett 2024; 269:106909. [PMID: 39128629 DOI: 10.1016/j.imlet.2024.106909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2024] [Revised: 08/01/2024] [Accepted: 08/08/2024] [Indexed: 08/13/2024]
Abstract
Activation-induced cytidine deaminase (AID) is responsible for the initiation of somatic hypermutation (SHM) and class-switch recombination (CSR), which result in antibody affinity maturation and isotype switching, thus producing pathogen-specific antibodies. Chromatin dynamics and accessibility play a significant role in determining AID expression and its targeting. Chromatin remodelers contribute to the accessibility of the chromatin structure, thereby influencing the targeting of AID to Ig genes. Epigenetic modifications, including DNA methylation, histone modifications, and miRNA expression, profoundly impact the regulation of AID and chromatin remodelers targeting Ig genes. Additionally, epigenetic modifications lead to chromatin rearrangement and thereby can change AID expression levels and its preferential targeting to Ig genes. This interplay is symbolized as the ACE phenomenon encapsulates three interconnected aspects: AID, Chromatin remodelers, and Epigenetic modifications. This review emphasizes the importance of understanding the intricate relationship between these aspects to unlock the therapeutic potential of these molecular processes and molecules.
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Affiliation(s)
- Saurav Sharma
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Simrol, Khandwa Road, Indore, 453552, India
| | - Mallar Dasgupta
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Simrol, Khandwa Road, Indore, 453552, India
| | - Bindu Sai Vadaga
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Simrol, Khandwa Road, Indore, 453552, India
| | - Prashant Kodgire
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Simrol, Khandwa Road, Indore, 453552, India.
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2
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Rangel V, Sterrenberg JN, Garawi A, Mezcord V, Folkerts ML, Calderon SE, Garcia YE, Wang J, Soyfer EM, Eng OS, Valerin JB, Tanjasiri SP, Quintero-Rivera F, Seldin MM, Masri S, Frock RL, Fleischman AG, Pannunzio NR. Increased AID results in mutations at the CRLF2 locus implicated in Latin American ALL health disparities. Nat Commun 2024; 15:6331. [PMID: 39068148 PMCID: PMC11283463 DOI: 10.1038/s41467-024-50537-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 07/10/2024] [Indexed: 07/30/2024] Open
Abstract
Activation-induced cytidine deaminase (AID) is a B cell-specific mutator required for antibody diversification. However, it is also implicated in the etiology of several B cell malignancies. Evaluating the AID-induced mutation load in patients at-risk for certain blood cancers is critical in assessing disease severity and treatment options. We have developed a digital PCR (dPCR) assay that allows us to quantify mutations resulting from AID modification or DNA double-strand break (DSB) formation and repair at sites known to be prone to DSBs. Implementation of this assay shows that increased AID levels in immature B cells increase genome instability at loci linked to chromosomal translocation formation. This includes the CRLF2 locus that is often involved in translocations associated with a subtype of acute lymphoblastic leukemia (ALL) that disproportionately affects Hispanics, particularly those with Latin American ancestry. Using dPCR, we characterize the CRLF2 locus in B cell-derived genomic DNA from both Hispanic ALL patients and healthy Hispanic donors and found increased mutations in both, suggesting that vulnerability to DNA damage at CRLF2 may be driving this health disparity. Our ability to detect and quantify these mutations will potentiate future risk identification, early detection of cancers, and reduction of associated cancer health disparities.
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Affiliation(s)
- Valeria Rangel
- Division of Hematology/Oncology, Department of Medicine, University of California, Irvine, Irvine, CA, USA
- Department of Biological Chemistry, University of California, Irvine, Irvine, CA, USA
| | - Jason N Sterrenberg
- Division of Hematology/Oncology, Department of Medicine, University of California, Irvine, Irvine, CA, USA
| | - Aya Garawi
- School of Biological Sciences, University of California, Irvine, Irvine, CA, USA
| | - Vyanka Mezcord
- Center for Applied Biotechnology Studies, Department of Biological Science, California State University Fullerton, Fullerton, CA, USA
| | - Melissa L Folkerts
- Division of Hematology/Oncology, Department of Medicine, University of California, Irvine, Irvine, CA, USA
- Department of Biological Chemistry, University of California, Irvine, Irvine, CA, USA
| | - Sabrina E Calderon
- School of Biological Sciences, University of California, Irvine, Irvine, CA, USA
| | - Yadhira E Garcia
- Department of Pharmaceutical Sciences, School of Pharmacy & Pharmaceutical Sciences, University of California, Irvine, CA, USA
| | - Jinglong Wang
- Division of Radiation and Cancer Biology, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | - Eli M Soyfer
- Division of Hematology/Oncology, Department of Medicine, University of California, Irvine, Irvine, CA, USA
- Department of Biological Chemistry, University of California, Irvine, Irvine, CA, USA
| | - Oliver S Eng
- Division of Surgical Oncology, Department of Surgery, University of California, Irvine, Irvine, CA, USA
- Chao Family Comprehensive Cancer Center, University of California, Irvine, Irvine, CA, USA
| | - Jennifer B Valerin
- Division of Hematology/Oncology, Department of Medicine, University of California, Irvine, Irvine, CA, USA
- Chao Family Comprehensive Cancer Center, University of California, Irvine, Irvine, CA, USA
| | - Sora Park Tanjasiri
- Chao Family Comprehensive Cancer Center, University of California, Irvine, Irvine, CA, USA
- Department of Health, Society and Behavior, University of California, Irvine, Irvine, CA, USA
| | - Fabiola Quintero-Rivera
- Department of Pathology and Laboratory Medicine, University of California, Irvine, Irvine, CA, USA
- Department of Pediatrics, University of California, Irvine, Irvine, CA, USA
| | - Marcus M Seldin
- Department of Biological Chemistry, University of California, Irvine, Irvine, CA, USA
- Chao Family Comprehensive Cancer Center, University of California, Irvine, Irvine, CA, USA
| | - Selma Masri
- Department of Biological Chemistry, University of California, Irvine, Irvine, CA, USA
- Chao Family Comprehensive Cancer Center, University of California, Irvine, Irvine, CA, USA
| | - Richard L Frock
- Division of Radiation and Cancer Biology, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | - Angela G Fleischman
- Division of Hematology/Oncology, Department of Medicine, University of California, Irvine, Irvine, CA, USA
- Department of Biological Chemistry, University of California, Irvine, Irvine, CA, USA
- Chao Family Comprehensive Cancer Center, University of California, Irvine, Irvine, CA, USA
| | - Nicholas R Pannunzio
- Division of Hematology/Oncology, Department of Medicine, University of California, Irvine, Irvine, CA, USA.
- Department of Biological Chemistry, University of California, Irvine, Irvine, CA, USA.
- Chao Family Comprehensive Cancer Center, University of California, Irvine, Irvine, CA, USA.
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3
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Hao Q, Li J, Yeap LS. Molecular mechanisms of DNA lesion and repair during antibody somatic hypermutation. SCIENCE CHINA. LIFE SCIENCES 2024:10.1007/s11427-024-2615-1. [PMID: 39048716 DOI: 10.1007/s11427-024-2615-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Accepted: 05/08/2024] [Indexed: 07/27/2024]
Abstract
Antibody diversification is essential for an effective immune response, with somatic hypermutation (SHM) serving as a key molecular process in this adaptation. Activation-induced cytidine deaminase (AID) initiates SHM by inducing DNA lesions, which are ultimately resolved into point mutations, as well as small insertions and deletions (indels). These mutational outcomes contribute to antibody affinity maturation. The mechanisms responsible for generating point mutations and indels involve the base excision repair (BER) and mismatch repair (MMR) pathways, which are well coordinated to maintain genomic integrity while allowing for beneficial mutations to occur. In this regard, translesion synthesis (TLS) polymerases contribute to the diversity of mutational outcomes in antibody genes by enabling the bypass of DNA lesions. This review summarizes our current understanding of the distinct molecular mechanisms that generate point mutations and indels during SHM. Understanding these mechanisms is critical for elucidating the development of broadly neutralizing antibodies (bnAbs) and autoantibodies, and has implications for vaccine design and therapeutics.
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Affiliation(s)
- Qian Hao
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Department of Endocrinology and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Jinfeng Li
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Department of Endocrinology and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Leng-Siew Yeap
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Department of Endocrinology and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
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Subramani PG, Fraszczak J, Helness A, Estall JL, Möröy T, Di Noia JM. Conserved role of hnRNPL in alternative splicing of epigenetic modifiers enables B cell activation. EMBO Rep 2024; 25:2662-2697. [PMID: 38744970 PMCID: PMC11169469 DOI: 10.1038/s44319-024-00152-3] [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: 10/05/2023] [Revised: 04/15/2024] [Accepted: 04/24/2024] [Indexed: 05/16/2024] Open
Abstract
The multifunctional RNA-binding protein hnRNPL is implicated in antibody class switching but its broader function in B cells is unknown. Here, we show that hnRNPL is essential for B cell activation, germinal center formation, and antibody responses. Upon activation, hnRNPL-deficient B cells show proliferation defects and increased apoptosis. Comparative analysis of RNA-seq data from activated B cells and another eight hnRNPL-depleted cell types reveals common effects on MYC and E2F transcriptional programs required for proliferation. Notably, while individual gene expression changes are cell type specific, several alternative splicing events affecting histone modifiers like KDM6A and SIRT1, are conserved across cell types. Moreover, hnRNPL-deficient B cells show global changes in H3K27me3 and H3K9ac. Epigenetic dysregulation after hnRNPL loss could underlie differential gene expression and upregulation of lncRNAs, and explain common and cell type-specific phenotypes, such as dysfunctional mitochondria and ROS overproduction in mouse B cells. Thus, hnRNPL is essential for the resting-to-activated B cell transition by regulating transcriptional programs and metabolism, at least in part through the alternative splicing of several histone modifiers.
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Affiliation(s)
- Poorani Ganesh Subramani
- Institut de Recherches Cliniques de Montréal, 110 avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada
- Department of Medicine, Division of Experimental Medicine, McGill University, 1001 Boulevard Decarie, Montreal, QC, H4A 3J1, Canada
| | - Jennifer Fraszczak
- Institut de Recherches Cliniques de Montréal, 110 avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada
| | - Anne Helness
- Institut de Recherches Cliniques de Montréal, 110 avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada
| | - Jennifer L Estall
- Institut de Recherches Cliniques de Montréal, 110 avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada
- Department of Medicine, Division of Experimental Medicine, McGill University, 1001 Boulevard Decarie, Montreal, QC, H4A 3J1, Canada
- Molecular Biology Programs, Université de Montréal, C.P. 6128, succ. Centre-ville, Montréal, QC, H3C 3J7, Canada
- Department of Medicine, Université de Montréal, C.P. 6128, succ. Centre-ville, Montréal, QC, H3C 3J7, Canada
| | - Tarik Möröy
- Institut de Recherches Cliniques de Montréal, 110 avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada
- Department of Medicine, Division of Experimental Medicine, McGill University, 1001 Boulevard Decarie, Montreal, QC, H4A 3J1, Canada
- Molecular Biology Programs, Université de Montréal, C.P. 6128, succ. Centre-ville, Montréal, QC, H3C 3J7, Canada
- Département de microbiologie, infectiologie et immunologie, Université de Montréal, 2900 Boul Edouard-Montpetit, Montréal, QC, H3T 1J4, Canada
| | - Javier M Di Noia
- Institut de Recherches Cliniques de Montréal, 110 avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada.
- Department of Medicine, Division of Experimental Medicine, McGill University, 1001 Boulevard Decarie, Montreal, QC, H4A 3J1, Canada.
- Molecular Biology Programs, Université de Montréal, C.P. 6128, succ. Centre-ville, Montréal, QC, H3C 3J7, Canada.
- Department of Medicine, Université de Montréal, C.P. 6128, succ. Centre-ville, Montréal, QC, H3C 3J7, Canada.
- Département de microbiologie, infectiologie et immunologie, Université de Montréal, 2900 Boul Edouard-Montpetit, Montréal, QC, H3T 1J4, Canada.
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Mu DP, Scharer CD, Kaminski NE, Zhang Q. A multiscale spatial modeling framework for the germinal center response. Front Immunol 2024; 15:1377303. [PMID: 38881901 PMCID: PMC11179717 DOI: 10.3389/fimmu.2024.1377303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2024] [Accepted: 05/14/2024] [Indexed: 06/18/2024] Open
Abstract
The germinal center response or reaction (GCR) is a hallmark event of adaptive humoral immunity. Unfolding in the B cell follicles of the secondary lymphoid organs, a GC culminates in the production of high-affinity antibody-secreting plasma cells along with memory B cells. By interacting with follicular dendritic cells (FDC) and T follicular helper (Tfh) cells, GC B cells exhibit complex spatiotemporal dynamics. Driving the B cell dynamics are the intracellular signal transduction and gene regulatory network that responds to cell surface signaling molecules, cytokines, and chemokines. As our knowledge of the GC continues to expand in depth and in scope, mathematical modeling has become an important tool to help disentangle the intricacy of the GCR and inform novel mechanistic and clinical insights. While the GC has been modeled at different granularities, a multiscale spatial simulation framework - integrating molecular, cellular, and tissue-level responses - is still rare. Here, we report our recent progress toward this end with a hybrid stochastic GC framework developed on the Cellular Potts Model-based CompuCell3D platform. Tellurium is used to simulate the B cell intracellular molecular network comprising NF-κB, FOXO1, MYC, AP4, CXCR4, and BLIMP1 that responds to B cell receptor (BCR) and CD40-mediated signaling. The molecular outputs of the network drive the spatiotemporal behaviors of B cells, including cyclic migration between the dark zone (DZ) and light zone (LZ) via chemotaxis; clonal proliferative bursts, somatic hypermutation, and DNA damage-induced apoptosis in the DZ; and positive selection, apoptosis via a death timer, and emergence of plasma cells in the LZ. Our simulations are able to recapitulate key molecular, cellular, and morphological GC events, including B cell population growth, affinity maturation, and clonal dominance. This novel modeling framework provides an open-source, customizable, and multiscale virtual GC simulation platform that enables qualitative and quantitative in silico investigations of a range of mechanistic and applied research questions on the adaptive humoral immune response in the future.
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Affiliation(s)
- Derek P. Mu
- Montgomery Blair High School, Silver Spring, MD, United States
| | - Christopher D. Scharer
- Department of Microbiology and Immunology, School of Medicine, Emory University, Atlanta, GA, United States
| | - Norbert E. Kaminski
- Department of Pharmacology & Toxicology, Institute for Integrative Toxicology, Center for Research on Ingredient Safety, Michigan State University, East Lansing, MI, United States
| | - Qiang Zhang
- Gangarosa Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, United States
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Tambe A, MacCarthy T, Pavri R. Interpretable deep learning reveals the role of an E-box motif in suppressing somatic hypermutation of AGCT motifs within human immunoglobulin variable regions. Front Immunol 2024; 15:1407470. [PMID: 38863710 PMCID: PMC11165027 DOI: 10.3389/fimmu.2024.1407470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Accepted: 05/08/2024] [Indexed: 06/13/2024] Open
Abstract
Introduction Somatic hypermutation (SHM) of immunoglobulin variable (V) regions by activation induced deaminase (AID) is essential for robust, long-term humoral immunity against pathogen and vaccine antigens. AID mutates cytosines preferentially within WRCH motifs (where W=A or T, R=A or G and H=A, C or T). However, it has been consistently observed that the mutability of WRCH motifs varies substantially, with large variations in mutation frequency even between multiple occurrences of the same motif within a single V region. This has led to the notion that the immediate sequence context of WRCH motifs contributes to mutability. Recent studies have highlighted the potential role of local DNA sequence features in promoting mutagenesis of AGCT, a commonly mutated WRCH motif. Intriguingly, AGCT motifs closer to 5' ends of V regions, within the framework 1 (FW1) sub-region1, mutate less frequently, suggesting an SHM-suppressing sequence context. Methods Here, we systematically examined the basis of AGCT positional biases in human SHM datasets with DeepSHM, a machine-learning model designed to predict SHM patterns. This was combined with integrated gradients, an interpretability method, to interrogate the basis of DeepSHM predictions. Results DeepSHM predicted the observed positional differences in mutation frequencies at AGCT motifs with high accuracy. For the conserved, lowly mutating AGCT motifs in FW1, integrated gradients predicted a large negative contribution of 5'C and 3'G flanking residues, suggesting that a CAGCTG context in this location was suppressive for SHM. CAGCTG is the recognition motif for E-box transcription factors, including E2A, which has been implicated in SHM. Indeed, we found a strong, inverse relationship between E-box motif fidelity and mutation frequency. Moreover, E2A was found to associate with the V region locale in two human B cell lines. Finally, analysis of human SHM datasets revealed that naturally occurring mutations in the 3'G flanking residues, which effectively ablate the E-box motif, were associated with a significantly increased rate of AGCT mutation. Discussion Our results suggest an antagonistic relationship between mutation frequency and the binding of E-box factors like E2A at specific AGCT motif contexts and, therefore, highlight a new, suppressive mechanism regulating local SHM patterns in human V regions.
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Affiliation(s)
- Abhik Tambe
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY, United States
| | - Thomas MacCarthy
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, NY, United States
| | - Rushad Pavri
- Research Institute of Molecular Pathology (IMP), Vienna, Austria
- Peter Gorer Department of Immunobiology, School of Immunology & Microbial Sciences, King’s College London, London, United Kingdom
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Chen R, Mu H, Chen X, Tsumura M, Zhou L, Jiang X, Zhang Z, Tang X, Chen Y, Jia Y, Okada S, Zhao X, An Y. Qualitative Immunoglobulin Deficiency Causes Bacterial Infections in Patients with STAT1 Gain-of-Function Mutations. J Clin Immunol 2024; 44:124. [PMID: 38758476 DOI: 10.1007/s10875-024-01720-x] [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: 01/09/2024] [Accepted: 04/22/2024] [Indexed: 05/18/2024]
Abstract
PURPOSES STAT1 is a transduction and transcriptional regulator that functions within the classical JAK/STAT pathway. In addition to chronic mucocutaneous candidiasis, bacterial infections are a common occurrence in patients with STAT1 gain-of-function (GOF) mutations. These patients often exhibit skewing of B cell subsets; however, the impact of STAT1-GOF mutations on B cell-mediated humoral immunity remains largely unexplored. It is also unclear whether these patients with IgG within normal range require regular intravenous immunoglobulin (IVIG) therapy. METHODS Eleven patients (harboring nine different STAT1-GOF mutations) were enrolled. Reporter assays and immunoblot analyses were performed to confirm STAT1 mutations. Flow cytometry, deep sequencing, ELISA, and ELISpot were conducted to assess the impact of STAT1-GOF on humoral immunity. RESULTS All patients exhibited increased levels of phospho-STAT1 and total STAT1 protein, with two patients carrying novel mutations. In vitro assays showed that these two novel mutations were GOF mutations. Three patients with normal total IgG levels received regular IVIG infusions, resulting in effective control of bacterial infections. Four cases showed impaired affinity and specificity of pertussis toxin-specific antibodies, accompanied by reduced generation of class-switched memory B cells. Patients also had a disrupted immunoglobulin heavy chain (IGH) repertoire, coupled with a marked reduction in the somatic hypermutation frequency of switched Ig transcripts. CONCLUSION STAT1-GOF mutations disrupt B cell compartments and skew IGH characteristics, resulting in impaired affinity and antigen-specificity of antibodies and recurrent bacterial infections. Regular IVIG therapy can control these infections in patients, even those with normal total IgG levels.
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Affiliation(s)
- Ran Chen
- National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Child Rare Diseases in Infection and Immunity, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Huilin Mu
- National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Child Rare Diseases in Infection and Immunity, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Xuemei Chen
- Department of Rheumatology and Immunology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Miyuki Tsumura
- Department of Pediatrics, Graduate School of Biomedical and Health Sciences, 1-2-3 Kasumi, Minami-Ku, Hiroshima, 734-8551, Japan
| | - Lina Zhou
- National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Child Rare Diseases in Infection and Immunity, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Xinhui Jiang
- Department of Nephrology and Immunology, Guiyang Maternal & Child Health Care Hospital, Guiyang, China
| | - Zhiyong Zhang
- National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Child Rare Diseases in Infection and Immunity, Children's Hospital of Chongqing Medical University, Chongqing, China
- Department of Rheumatology and Immunology, Children's Hospital of Chongqing Medical University, No. 136, Zhongshan 2nd Road, Yuzhong District, Chongqing, 400014, China
| | - Xuemei Tang
- National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Child Rare Diseases in Infection and Immunity, Children's Hospital of Chongqing Medical University, Chongqing, China
- Department of Rheumatology and Immunology, Children's Hospital of Chongqing Medical University, No. 136, Zhongshan 2nd Road, Yuzhong District, Chongqing, 400014, China
| | - Yongwen Chen
- Institute of Immunology, PLA, Third Military Medical University, Chongqing, 400038, People's Republic of China
| | - Yanjun Jia
- National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Child Rare Diseases in Infection and Immunity, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Satoshi Okada
- Department of Pediatrics, Graduate School of Biomedical and Health Sciences, 1-2-3 Kasumi, Minami-Ku, Hiroshima, 734-8551, Japan.
| | - Xiaodong Zhao
- National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Child Rare Diseases in Infection and Immunity, Children's Hospital of Chongqing Medical University, Chongqing, China.
- Department of Rheumatology and Immunology, Children's Hospital of Chongqing Medical University, No. 136, Zhongshan 2nd Road, Yuzhong District, Chongqing, 400014, China.
| | - Yunfei An
- National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Child Rare Diseases in Infection and Immunity, Children's Hospital of Chongqing Medical University, Chongqing, China.
- Department of Rheumatology and Immunology, Children's Hospital of Chongqing Medical University, No. 136, Zhongshan 2nd Road, Yuzhong District, Chongqing, 400014, China.
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8
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Mu Y, Chen Z, Plummer JB, Zelazowska MA, Dong Q, Krug LT, McBride KM. UNG-RPA interaction governs the choice between high-fidelity and mutagenic uracil repair. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.30.591927. [PMID: 38746347 PMCID: PMC11092621 DOI: 10.1101/2024.04.30.591927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Mammalian Uracil DNA glycosylase (UNG) removes uracils and initiates high-fidelity base excision repair to maintain genomic stability. During B cell development, activation-induced cytidine deaminase (AID) creates uracils that UNG processes in an error-prone fashion to accomplish immunoglobulin (Ig) somatic hypermutation (SHM) or class switch recombination (CSR). The mechanism that governs high-fidelity versus mutagenic uracil repair is not understood. The B cell tropic gammaherpesvirus (GHV) encodes a functional homolog of UNG that can process AID induced genomic uracils. GHVUNG does not support hypermutation, suggesting intrinsic properties of UNG influence repair outcome. Noting the structural divergence between the UNGs, we define the RPA interacting motif as the determinant of mutation outcome. UNG or RPA mutants unable to interact with each other, only support high-fidelity repair. In B cells, transversions at the Ig variable region are abated while CSR is supported. Thus UNG-RPA governs the generation of mutations and has implications for locus specific mutagenesis in B cells and deamination associated mutational signatures in cancer.
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Ng JCF, Montamat Garcia G, Stewart AT, Blair P, Mauri C, Dunn-Walters DK, Fraternali F. sciCSR infers B cell state transition and predicts class-switch recombination dynamics using single-cell transcriptomic data. Nat Methods 2024; 21:823-834. [PMID: 37932398 PMCID: PMC11093741 DOI: 10.1038/s41592-023-02060-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 10/02/2023] [Indexed: 11/08/2023]
Abstract
Class-switch recombination (CSR) is an integral part of B cell maturation. Here we present sciCSR (pronounced 'scissor', single-cell inference of class-switch recombination), a computational pipeline that analyzes CSR events and dynamics of B cells from single-cell RNA sequencing (scRNA-seq) experiments. Validated on both simulated and real data, sciCSR re-analyzes scRNA-seq alignments to differentiate productive heavy-chain immunoglobulin transcripts from germline 'sterile' transcripts. From a snapshot of B cell scRNA-seq data, a Markov state model is built to infer the dynamics and direction of CSR. Applying sciCSR on severe acute respiratory syndrome coronavirus 2 vaccination time-course scRNA-seq data, we observe that sciCSR predicts, using data from an earlier time point in the collected time-course, the isotype distribution of B cell receptor repertoires of subsequent time points with high accuracy (cosine similarity ~0.9). Using processes specific to B cells, sciCSR identifies transitions that are often missed by conventional RNA velocity analyses and can reveal insights into the dynamics of B cell CSR during immune response.
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Affiliation(s)
- Joseph C F Ng
- Department of Structural and Molecular Biology, Division of Biosciences and Institute of Structural and Molecular Biology, University College London, London, UK.
| | - Guillem Montamat Garcia
- Division of Infection and Immunity and Institute of Immunity and Transplantation, Royal Free Hospital, University College London, London, UK
| | | | - Paul Blair
- Division of Infection and Immunity and Institute of Immunity and Transplantation, Royal Free Hospital, University College London, London, UK
| | - Claudia Mauri
- Division of Infection and Immunity and Institute of Immunity and Transplantation, Royal Free Hospital, University College London, London, UK
| | | | - Franca Fraternali
- Department of Structural and Molecular Biology, Division of Biosciences and Institute of Structural and Molecular Biology, University College London, London, UK.
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10
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Mu DP, Scharer CD, Kaminski NE, Zhang Q. A Multiscale Spatial Modeling Framework for the Germinal Center Response. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.26.577491. [PMID: 38501122 PMCID: PMC10945589 DOI: 10.1101/2024.01.26.577491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/20/2024]
Abstract
The germinal center response or reaction (GCR) is a hallmark event of adaptive humoral immunity. Unfolding in the B cell follicles of the secondary lymph organs, a GC culminates in the production of high-affinity antibody-secreting plasma cells along with memory B cells. By interacting with follicular dendritic cells (FDC) and T follicular helper (Tfh) cells, GC B cells exhibit complex spatiotemporal dynamics. Driving the B cell dynamics are the intracellular signal transduction and gene regulatory network that responds to cell surface signaling molecules, cytokines, and chemokines. As our knowledge of the GC continues to expand in depth and in scope, mathematical modeling has become an important tool to help disentangle the intricacy of the GCR and inform novel mechanistic and clinical insights. While the GC has been modeled at different granularities, a multiscale spatial simulation framework - integrating molecular, cellular, and tissue-level responses - is still rare. Here, we report our recent progress toward this end with a hybrid stochastic GC framework developed on the Cellular Potts Model-based CompuCell3D platform. Tellurium is used to simulate the B cell intracellular molecular network comprising NF-κB, FOXO1, MYC, AP4, CXCR4, and BLIMP1 that responds to B cell receptor (BCR) and CD40-mediated signaling. The molecular outputs of the network drive the spatiotemporal behaviors of B cells, including cyclic migration between the dark zone (DZ) and light zone (LZ) via chemotaxis; clonal proliferative bursts, somatic hypermutation, and DNA damage-induced apoptosis in the DZ; and positive selection, apoptosis via a death timer, and emergence of plasma cells in the LZ. Our simulations are able to recapitulate key molecular, cellular, and morphological GC events including B cell population growth, affinity maturation, and clonal dominance. This novel modeling framework provides an open-source, customizable, and multiscale virtual GC simulation platform that enables qualitative and quantitative in silico investigations of a range of mechanic and applied research questions in future.
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11
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Hayran AB, Liabakk NB, Aas PA, Kusnierczyk A, Vågbø CB, Sarno A, Iveland TS, Chawla K, Zahn A, Di Noia JM, Slupphaug G, Kavli B. RPA guides UNG to uracil in ssDNA to facilitate antibody class switching and repair of mutagenic uracil at the replication fork. Nucleic Acids Res 2024; 52:784-800. [PMID: 38000394 PMCID: PMC10810282 DOI: 10.1093/nar/gkad1115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 10/27/2023] [Accepted: 11/06/2023] [Indexed: 11/26/2023] Open
Abstract
Activation-induced cytidine deaminase (AID) interacts with replication protein A (RPA), the major ssDNA-binding protein, to promote deamination of cytosine to uracil in transcribed immunoglobulin (Ig) genes. Uracil-DNA glycosylase (UNG) acts in concert with AID during Ig diversification. In addition, UNG preserves genome integrity by base-excision repair (BER) in the overall genome. How UNG is regulated to support both mutagenic processing and error-free repair remains unknown. UNG is expressed as two isoforms, UNG1 and UNG2, which both contain an RPA-binding helix that facilitates uracil excision from RPA-coated ssDNA. However, the impact of this interaction in antibody diversification and genome maintenance has not been investigated. Here, we generated B-cell clones with targeted mutations in the UNG RPA-binding motif, and analysed class switch recombination (CSR), mutation frequency (5' Ig Sμ), and genomic uracil in clones representing seven Ung genotypes. We show that the UNG:RPA interaction plays a crucial role in both CSR and repair of AID-induced uracil at the Ig loci. By contrast, the interaction had no significant impact on total genomic uracil levels. Thus, RPA coordinates UNG during CSR and pre-replicative repair of mutagenic uracil in ssDNA but is not essential in post-replicative and canonical BER of uracil in dsDNA.
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Affiliation(s)
- Abdul B Hayran
- Department of Clinical and Molecular Medicine, NTNU Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Nina B Liabakk
- Department of Clinical and Molecular Medicine, NTNU Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Per A Aas
- Department of Clinical and Molecular Medicine, NTNU Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Anna Kusnierczyk
- Department of Clinical and Molecular Medicine, NTNU Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
- PROMEC - Proteomics and Modomics Experimental Core Facility at NTNU and the Central Norway Regional Health Authority, NO-7491 Trondheim, Norway
| | - Cathrine B Vågbø
- Department of Clinical and Molecular Medicine, NTNU Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
- PROMEC - Proteomics and Modomics Experimental Core Facility at NTNU and the Central Norway Regional Health Authority, NO-7491 Trondheim, Norway
| | - Antonio Sarno
- Department of Clinical and Molecular Medicine, NTNU Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Tobias S Iveland
- Department of Clinical and Molecular Medicine, NTNU Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
- Cancer Clinic, St. Olav's Hospital, Trondheim University Hospital, NO-7006 Trondheim, Norway
| | - Konika Chawla
- Department of Clinical and Molecular Medicine, NTNU Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
- BioCore - Bioinformatics Core Facility at NTNU and the Central Norway Regional Health Authority, NO-7491 Trondheim, Norway
| | - Astrid Zahn
- Institut de Recherches Cliniques de Montréal, 110 Av des Pins Ouest, Montréal, QC H2W 1R7, Canada
| | - Javier M Di Noia
- Institut de Recherches Cliniques de Montréal, 110 Av des Pins Ouest, Montréal, QC H2W 1R7, Canada
- Département of Médicine, Université de Montréal H3C 3J7 Montréal, Québec, Canada
| | - Geir Slupphaug
- Department of Clinical and Molecular Medicine, NTNU Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
- PROMEC - Proteomics and Modomics Experimental Core Facility at NTNU and the Central Norway Regional Health Authority, NO-7491 Trondheim, Norway
- Clinic of Laboratory Medicine, St. Olav's Hospital, Trondheim University Hospital, NO-7006 Trondheim, Norway
| | - Bodil Kavli
- Department of Clinical and Molecular Medicine, NTNU Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
- Clinic of Laboratory Medicine, St. Olav's Hospital, Trondheim University Hospital, NO-7006 Trondheim, Norway
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12
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Salem GM, Galula JU, Wu SR, Liu JH, Chen YH, Wang WH, Wang SF, Song CS, Chen FC, Abarientos AB, Chen GW, Wang CI, Chao DY. Antibodies from dengue patients with prior exposure to Japanese encephalitis virus are broadly neutralizing against Zika virus. Commun Biol 2024; 7:15. [PMID: 38267569 PMCID: PMC10808242 DOI: 10.1038/s42003-023-05661-w] [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: 10/07/2023] [Accepted: 12/01/2023] [Indexed: 01/26/2024] Open
Abstract
Exposure to multiple mosquito-borne flaviviruses within a lifetime is not uncommon; however, how sequential exposures to different flaviviruses shape the cross-reactive humoral response against an antigen from a different serocomplex has yet to be explored. Here, we report that dengue-infected individuals initially primed with the Japanese encephalitis virus (JEV) showed broad, highly neutralizing potencies against Zika virus (ZIKV). We also identified a rare class of ZIKV-cross-reactive human monoclonal antibodies with increased somatic hypermutation and broad neutralization against multiple flaviviruses. One huMAb, K8b, binds quaternary epitopes with heavy and light chains separately interacting with overlapping envelope protein dimer units spanning domains I, II, and III through cryo-electron microscopy and structure-based mutagenesis. JEV virus-like particle immunization in mice further confirmed that such cross-reactive antibodies, mainly IgG3 isotype, can be induced and proliferate through heterologous dengue virus (DENV) serotype 2 virus-like particle stimulation. Our findings highlight the role of prior immunity in JEV and DENV in shaping the breadth of humoral response and provide insights for future vaccination strategies in flavivirus-endemic countries.
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Affiliation(s)
- Gielenny M Salem
- Graduate Institute of Microbiology and Public Health, College of Veterinary Medicine, National Chung Hsing University, Taichung City, 402, Taiwan
| | - Jedhan Ucat Galula
- Graduate Institute of Microbiology and Public Health, College of Veterinary Medicine, National Chung Hsing University, Taichung City, 402, Taiwan
| | - Shang-Rung Wu
- Institute of Oral Medicine, School of Dentistry, College of Medicine, National Cheng Kung University, Tainan City, 701, Taiwan
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan City, 701, Taiwan
| | - Jyung-Hurng Liu
- Graduate Institute of Genomics and Bioinformatics, College of Life Sciences, National Chung Hsing University, Taichung City, 40227, Taiwan
| | - Yen-Hsu Chen
- School of Medicine, College of Medicine, National Sun Yat-Sen University, Kaohsiung City, 80424, Taiwan
- Center for Tropical Medicine and Infectious Disease Research, Kaohsiung Medical University, Kaohsiung City, 80708, Taiwan
- Division of Infectious Diseases, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung City, 80708, Taiwan
| | - Wen-Hung Wang
- School of Medicine, College of Medicine, National Sun Yat-Sen University, Kaohsiung City, 80424, Taiwan
- Center for Tropical Medicine and Infectious Disease Research, Kaohsiung Medical University, Kaohsiung City, 80708, Taiwan
- Division of Infectious Diseases, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung City, 80708, Taiwan
| | - Sheng-Fan Wang
- Center for Tropical Medicine and Infectious Disease Research, Kaohsiung Medical University, Kaohsiung City, 80708, Taiwan
- Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, Kaohsiung City, 80708, Taiwan
| | - Cheng-Sheng Song
- Graduate Institute of Microbiology and Public Health, College of Veterinary Medicine, National Chung Hsing University, Taichung City, 402, Taiwan
| | - Fan-Chi Chen
- Doctoral Program in Microbial Genomics, National Chung Hsing University and Academia Sinica, Taichung City, 402, Taiwan
| | - Adrian B Abarientos
- Graduate Institute of Microbiology and Public Health, College of Veterinary Medicine, National Chung Hsing University, Taichung City, 402, Taiwan
| | - Guan-Wen Chen
- Institute of Oral Medicine, School of Dentistry, College of Medicine, National Cheng Kung University, Tainan City, 701, Taiwan
| | - Cheng-I Wang
- Singapore Immunology Network, Agency for Science, Technology and Research (A*STAR), 8A Biomedical Grove, Immunos, Singapore, 138648, Singapore
| | - Day-Yu Chao
- Graduate Institute of Microbiology and Public Health, College of Veterinary Medicine, National Chung Hsing University, Taichung City, 402, Taiwan.
- Doctoral Program in Microbial Genomics, National Chung Hsing University and Academia Sinica, Taichung City, 402, Taiwan.
- Department of Post-Baccalaureate Medicine, College of Medicine, National Chung Hsing University, Taichung City, 402, Taiwan.
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13
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Šenigl F, Soikkeli A, Prost S, Schatz DG, Slavková M, Hejnar J, Alinikula J. The SV40 virus enhancer functions as a somatic hypermutation-targeting element with potential oncogenic activity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.09.574829. [PMID: 38260396 PMCID: PMC10802419 DOI: 10.1101/2024.01.09.574829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Simian virus 40 (SV40) is a monkey virus associated with several types of human cancers. SV40 is most frequently detected in mesotheliomas, brain and bone tumors and lymphomas, but the mechanism for SV40 tumorigenesis in humans is not clear. SV40 relative Merkel cell polyomavirus (MCPyV) causes Merkel cell carcinoma (MCC) in humans by expressing truncated large tumor antigen (LT) caused by APOBEC cytidine deaminase family enzymes induced mutations. AID (activation-induced cytidine deaminase), a member of the APOBEC family, is the initiator of the antibody diversification process known as somatic hypermutation (SHM) and its aberrant expression and targeting is a frequent source of lymphomagenesis. In this study, we investigated whether AID-induced mutations could cause truncation of SV40 LT. We demonstrate that the SV40 enhancer has strong SHM targeting activity in several cell types and that AID-induced mutations accumulate to SV40 LT in B cells and kidney cells and cause truncated LT expression in B cells. Our results argue that the ability of the SV40 enhancer to target SHM to LT is a potential source of LT truncation events in various cell types that could contribute to carcinogenesis.
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14
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Dolbec D, Lehoux M, de Beauville AA, Zahn A, Di Noia JM, Segura M. Unmutated but T cell dependent IgM antibodies targeting Streptococcus suis play an essential role in bacterial clearance. PLoS Pathog 2024; 20:e1011957. [PMID: 38241393 PMCID: PMC10829992 DOI: 10.1371/journal.ppat.1011957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 01/31/2024] [Accepted: 01/08/2024] [Indexed: 01/21/2024] Open
Abstract
Streptococcus suis serotype 2 is an important encapsulated bacterial swine pathogen and zoonotic agent for which no effective vaccine exists. The interaction with B cells and the humoral response against S. suis are poorly understood despite their likely relevance for a potential vaccine. We evaluated germinal center (GC) B cell kinetics, as well as the production and role of S. suis-specific antibodies following infections in a mouse model. We found that mice infected with S. suis developed GC that peaked 13-21 days post-infection. GC further increased and persisted upon periodic reinfection that mimics real life conditions in swine farms. Anti-S. suis IgM and several IgG subclasses were produced, but antibodies against the S. suis capsular polysaccharide (CPS) were largely IgM. Interestingly, depletion of total IgG from the wild-type mice sera had no effect on bacterial killing by opsonophagocytosis in vitro. Somatic hypermutation and isotype switching were dispensable for controlling the infection or anti-CPS IgM production. However, T cell-deficient (Tcrb-/-) mice were unable to control bacteremia, produce optimal anti-CPS IgM titers, or elicit antibodies with opsonophagocytic activity. SAP deficiency, which prevents GC formation but not extrafollicular B cell responses, ablated anti S. suis-IgG production but maintained IgM production and eliminated the infection. In contrast, B cell deficient mice were unable to control bacteremia. Collectively, our results indicate that the antibody response plays a large role in immunity against S. suis, with GC-independent but T cell-dependent germline IgM being the major effective antibody specificities. Our results further highlight the importance IgM, and potentially anti-CPS antibodies, in clearing S. suis infections and provide insight for future development of S. suis vaccines.
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Affiliation(s)
- Dominic Dolbec
- Research Group on Infectious Diseases in Production Animals (GREMIP) and Swine and Poultry Infectious Diseases Research Center (CRIPA), Department of Pathology and Microbiology, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, Quebec, Canada
| | - Mélanie Lehoux
- Research Group on Infectious Diseases in Production Animals (GREMIP) and Swine and Poultry Infectious Diseases Research Center (CRIPA), Department of Pathology and Microbiology, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, Quebec, Canada
| | - Alexis Asselin de Beauville
- Research Group on Infectious Diseases in Production Animals (GREMIP) and Swine and Poultry Infectious Diseases Research Center (CRIPA), Department of Pathology and Microbiology, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, Quebec, Canada
| | - Astrid Zahn
- Institut de Recherches Cliniques de Montréal, Center for Immunity, Inflammation and Infectious Diseases, Quebec, Canada
| | - Javier Marcelo Di Noia
- Institut de Recherches Cliniques de Montréal, Center for Immunity, Inflammation and Infectious Diseases, Quebec, Canada
- Department of Medicine, Faculty of Sciences, University of Montreal, Montreal, Quebec, Canada
| | - Mariela Segura
- Research Group on Infectious Diseases in Production Animals (GREMIP) and Swine and Poultry Infectious Diseases Research Center (CRIPA), Department of Pathology and Microbiology, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, Quebec, Canada
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15
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Malzl D, Peycheva M, Rahjouei A, Gnan S, Klein KN, Nazarova M, Schoeberl UE, Gilbert DM, Buonomo SCB, Di Virgilio M, Neumann T, Pavri R. RIF1 regulates early replication timing in murine B cells. Nat Commun 2023; 14:8049. [PMID: 38081811 PMCID: PMC10713614 DOI: 10.1038/s41467-023-43778-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 11/20/2023] [Indexed: 12/18/2023] Open
Abstract
The mammalian DNA replication timing (RT) program is crucial for the proper functioning and integrity of the genome. The best-known mechanism for controlling RT is the suppression of late origins of replication in heterochromatin by RIF1. Here, we report that in antigen-activated, hypermutating murine B lymphocytes, RIF1 binds predominantly to early-replicating active chromatin and promotes early replication, but plays a minor role in regulating replication origin activity, gene expression and genome organization in B cells. Furthermore, we find that RIF1 functions in a complementary and non-epistatic manner with minichromosome maintenance (MCM) proteins to establish early RT signatures genome-wide and, specifically, to ensure the early replication of highly transcribed genes. These findings reveal additional layers of regulation within the B cell RT program, driven by the coordinated activity of RIF1 and MCM proteins.
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Affiliation(s)
- Daniel Malzl
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter, 1030, Vienna, Austria
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090, Lazarettgasse 14, Vienna, Austria
| | - Mihaela Peycheva
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter, 1030, Vienna, Austria
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090, Lazarettgasse 14, Vienna, Austria
| | - Ali Rahjouei
- Max-Delbruck Center for Molecular Medicine in the Helmholtz Association (MDC), 13125, Berlin, Germany
| | - Stefano Gnan
- School of Biological Sciences, Institute of Cell Biology, University of Edinburgh, Edinburgh, EH9 3FF, UK
| | - Kyle N Klein
- San Diego Biomedical Research Institute, San Diego, CA, 92121, USA
| | - Mariia Nazarova
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter, 1030, Vienna, Austria
| | - Ursula E Schoeberl
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter, 1030, Vienna, Austria
| | - David M Gilbert
- San Diego Biomedical Research Institute, San Diego, CA, 92121, USA
| | - Sara C B Buonomo
- School of Biological Sciences, Institute of Cell Biology, University of Edinburgh, Edinburgh, EH9 3FF, UK
| | - Michela Di Virgilio
- Max-Delbruck Center for Molecular Medicine in the Helmholtz Association (MDC), 13125, Berlin, Germany
| | - Tobias Neumann
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter, 1030, Vienna, Austria.
- Quantro Therapeutics, Vienna Biocenter, 1030, Vienna, Austria.
| | - Rushad Pavri
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter, 1030, Vienna, Austria.
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16
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Molina E, García-Gutiérrez L, Junco V, Perez-Olivares M, de Yébenes VG, Blanco R, Quevedo L, Acosta JC, Marín AV, Ulgiati D, Merino R, Delgado MD, Varela I, Regueiro JR, Moreno de Alborán I, Ramiro AR, León J. MYC directly transactivates CR2/CD21, the receptor of the Epstein-Barr virus, enhancing the viral infection of Burkitt lymphoma cells. Oncogene 2023; 42:3358-3370. [PMID: 37773203 DOI: 10.1038/s41388-023-02846-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 09/12/2023] [Accepted: 09/18/2023] [Indexed: 10/01/2023]
Abstract
MYC is an oncogenic transcription factor dysregulated in about half of total human tumors. While transcriptomic studies reveal more than 1000 genes regulated by MYC, a much smaller fraction of genes is directly transactivated by MYC. Virtually all Burkitt lymphoma (BL) carry chromosomal translocations involving MYC oncogene. Most endemic BL and a fraction of sporadic BL are associated with Epstein-Barr virus (EBV) infection. The currently accepted mechanism is that EBV is the BL-causing agent inducing MYC translocation. Herein we show that the EBV receptor, CR2 (also called CD21), is a direct MYC target gene. This is based on several pieces of evidence: MYC induces CR2 expression in both proliferating and arrested cells and in the absence of protein synthesis, binds the CR2 promoter and transactivates CR2 in an E-box-dependent manner. Moreover, using mice with conditional MYC ablation we show that MYC induces CR2 in primary B cells. Importantly, modulation of MYC levels directly correlates with EBV's ability of infection in BL cells. Altogether, in contrast to the widely accepted hypothesis for the correlation between EBV and BL, we propose an alternative hypothesis in which MYC dysregulation could be the first event leading to the subsequent EBV infection.
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Affiliation(s)
- Ester Molina
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain
- Departamento de Biología Molecular, Universidad de Cantabria, Santander, Spain
- The Hormel Institute, University of Minnesota, Austin, MN, USA
| | - Lucía García-Gutiérrez
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain
- Departamento de Biología Molecular, Universidad de Cantabria, Santander, Spain
| | - Vanessa Junco
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain
- Departamento de Biología Molecular, Universidad de Cantabria, Santander, Spain
| | - Mercedes Perez-Olivares
- Department of Immunology and Oncology, Centro Nacional de Biotecnología (CNB)-CSIC, Madrid, Spain
| | - Virginia G de Yébenes
- Centro Nacional de Investigaciones Cardiovasculares-CNIC Carlos III, Madrid, Spain
- Department of Immunology, Ophthalmology and ENT, Universidad Complutense, School of Medicine and 12 de Octubre Health Research Institute (imas12), Madrid, Spain
| | - Rosa Blanco
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain
- Departamento de Biología Molecular, Universidad de Cantabria, Santander, Spain
| | - Laura Quevedo
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain
- Departamento de Biología Molecular, Universidad de Cantabria, Santander, Spain
| | - Juan C Acosta
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain
- Departamento de Biología Molecular, Universidad de Cantabria, Santander, Spain
| | - Ana V Marín
- Department of Immunology, Ophthalmology and ENT, Universidad Complutense, School of Medicine and 12 de Octubre Health Research Institute (imas12), Madrid, Spain
| | - Daniela Ulgiati
- School of Biomedical Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Ramon Merino
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain
- Departamento de Biología Molecular, Universidad de Cantabria, Santander, Spain
| | - M Dolores Delgado
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain
- Departamento de Biología Molecular, Universidad de Cantabria, Santander, Spain
| | - Ignacio Varela
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain
- Departamento de Biología Molecular, Universidad de Cantabria, Santander, Spain
| | - José R Regueiro
- Department of Immunology, Ophthalmology and ENT, Universidad Complutense, School of Medicine and 12 de Octubre Health Research Institute (imas12), Madrid, Spain
| | | | - Almudena R Ramiro
- Centro Nacional de Investigaciones Cardiovasculares-CNIC Carlos III, Madrid, Spain
| | - Javier León
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain.
- Departamento de Biología Molecular, Universidad de Cantabria, Santander, Spain.
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17
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Kabrani E, Saha T, Di Virgilio M. DNA repair and antibody diversification: the 53BP1 paradigm. Trends Immunol 2023; 44:782-791. [PMID: 37640588 DOI: 10.1016/j.it.2023.08.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/01/2023] [Accepted: 08/03/2023] [Indexed: 08/31/2023]
Abstract
The DNA double-strand break (DSB) repair factor 53BP1 has long been implicated in V(D)J and class switch recombination (CSR) of mammalian lymphocyte receptors. However, the dissection of the underlying molecular activities is hampered by a paucity of studies [V(D)J] and plurality of phenotypes (CSR) associated with 53BP1 deficiency. Here, we revisit the currently accepted roles of 53BP1 in antibody diversification in view of the recent identification of its downstream effectors in DSB protection and latest advances in genome architecture. We propose that, in addition to end protection, 53BP1-mediated end-tethering stabilization is essential for CSR. Furthermore, we support a pre-DSB role during V(D)J recombination. Our perspective underscores the importance of evaluating repair of DSBs in relation to their dynamic architectural contexts.
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Affiliation(s)
- Eleni Kabrani
- Laboratory of Genome Diversification and Integrity, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin 13125, Germany.
| | - Tannishtha Saha
- Laboratory of Genome Diversification and Integrity, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin 13125, Germany; Freie Universität Berlin, Berlin 14195, Germany
| | - Michela Di Virgilio
- Laboratory of Genome Diversification and Integrity, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin 13125, Germany; Charité-Universitätsmedizin Berlin, Berlin 10117, Germany.
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18
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Gómez-Escolar C, Marina-Zárate E, Ramiro AR. Activation-induced deaminase expression defines mature B cell lymphoma in the mouse. Front Immunol 2023; 14:1268930. [PMID: 37809061 PMCID: PMC10558245 DOI: 10.3389/fimmu.2023.1268930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 09/06/2023] [Indexed: 10/10/2023] Open
Abstract
Germinal centers (GCs) are the sites of secondary antibody diversification and underlie the mechanism of action of many vaccination strategies. Activation-induced deaminase (AID) triggers secondary antibody diversification through the introduction of somatic changes in immunoglobulin genes which lead to the generation of antibodies of higher affinity and more specialized effector functions. However, AID can also target other genomic regions, giving rise to mutations and chromosome translocations with oncogenic potential. Many human lymphomas originate from mature B cells that have undergone the GC reaction, such as the diffuse large B cell lymphoma, the follicular lymphoma and Burkitt lymphoma, and carry chromosome translocations. Mature B cell lymphomagenesis has been modeled in the mouse by the genetic introduction of chromosome translocations. Here, we present an in-depth characterization of one such model, λ-MYC mice. We found that young pre-tumor stage mice had a prominent block in early B cell differentiation that resulted in the generation of very aggressive tumors lacking surface B cell receptor (BCR) expression, indicating that a large fraction of tumors in λ-MYC mice arise from B cell precursors rather than from mature B cells. Further, we assessed the contribution of AID to B cell lymphomagenesis in λ-MYC mice by using a genetic tracer of historical AID expression. Only a fraction of tumors contained cells of GC origin as defined by AID expression. AID-experienced tumors associated with longer survival and resembled mature B cell lymphomas. Thus, AID expression defines Burkitt lymphomagenesis in λ-MYC mice.
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Affiliation(s)
| | | | - Almudena R. Ramiro
- B Lymphocyte Biology Lab, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
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19
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Pannunzio N, Rangel V, Sterrenberg J, Garawi A, Mezcord V, Folkerts M, Caulderon S, Wang J, Soyfer E, Eng O, Valerin J, Tanjasiri S, Quintero-Rivera F, Masri S, Seldin M, Frock R, Fleischman A. Increased AID Results in Mutations at the CRLF2 Locus Implicated in Latin American ALL Health Disparities. RESEARCH SQUARE 2023:rs.3.rs-3332673. [PMID: 37790327 PMCID: PMC10543404 DOI: 10.21203/rs.3.rs-3332673/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Activation-induced cytidine deaminase (AID) is a B cell-specific base editor required during class switch recombination and somatic hypermutation for B cell maturation and antibody diversification. However, it has also been implicated as a factor in the etiology of several B cell malignancies. Evaluating the AID-induced mutation load in patients at-risk for certain types of blood cancers is critical in assessing disease severity and treatment options. Here, we have developed a digital PCR (dPCR) assay that allows us to track the mutational landscape resulting from AID modification or DNA double-strand break (DSB) formation and repair at sites known to be prone to DSBs. Implementation of this new assay showed that increased AID levels in immature B cells increases genome instability at loci linked to translocation formation. This included the CRLF2 locus that is often involved in chromosomal translocations associated with a subtype of acute lymphoblastic leukemia (ALL) that disproportionately affects Latin Americans (LAs). To support this LA-specific identification of AID mutation signatures, we characterized DNA from immature B cells isolated from the bone marrow of ALL patients. Our ability to detect and quantify these mutation signatures will potentiate future risk identification, early detection of cancers, and reduction of associated cancer health disparities.
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20
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Bello A, Hirth G, Voigt S, Tepper S, Jungnickel B. Mechanism and regulation of secondary immunoglobulin diversification. Cell Cycle 2023; 22:2070-2087. [PMID: 37909747 PMCID: PMC10761156 DOI: 10.1080/15384101.2023.2275397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 10/20/2023] [Indexed: 11/03/2023] Open
Abstract
Secondary immunoglobulin diversification by somatic hypermutation and class switch recombination in B cells is instrumental for an adequate adaptive humoral immune response. These genetic events may, however, also introduce aberrations into other cellular genes and thereby cause B cell malignancies. While the basic mechanism of somatic hypermutation and class switch recombination is now well understood, their regulation and in particular the mechanism of their specific targeting to immunoglobulin genes is still rather mysterious. In this review, we summarize the current knowledge on the mechanism and regulation of secondary immunoglobulin diversification and discuss known mechanisms of physiological targeting to immunoglobulin genes and mistargeting to other cellular genes. We summarize open questions in the field and provide an outlook on future research.
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Affiliation(s)
- Amanda Bello
- Institute of Biochemistry and Biophysics, Faculty of Biological Sciences, Friedrich Schiller University, Jena, Germany
| | - Gianna Hirth
- Institute of Biochemistry and Biophysics, Faculty of Biological Sciences, Friedrich Schiller University, Jena, Germany
| | - Stefanie Voigt
- Institute of Biochemistry and Biophysics, Faculty of Biological Sciences, Friedrich Schiller University, Jena, Germany
| | - Sandra Tepper
- Institute of Biochemistry and Biophysics, Faculty of Biological Sciences, Friedrich Schiller University, Jena, Germany
| | - Berit Jungnickel
- Institute of Biochemistry and Biophysics, Faculty of Biological Sciences, Friedrich Schiller University, Jena, Germany
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21
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Xu Z, Peng Q, Liu W, Demongeot J, Wei D. Antibody Dynamics Simulation-A Mathematical Exploration of Clonal Deletion and Somatic Hypermutation. Biomedicines 2023; 11:2048. [PMID: 37509687 PMCID: PMC10377040 DOI: 10.3390/biomedicines11072048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/14/2023] [Accepted: 07/19/2023] [Indexed: 07/30/2023] Open
Abstract
We have employed mathematical modeling techniques to construct a comprehensive framework for elucidating the intricate response mechanisms of the immune system, facilitating a deeper understanding of B-cell clonal deletion and somatic hypermutation. Our improved model introduces innovative mechanisms that shed light on positive and negative selection processes during T-cell and B-cell development. Notably, clonal deletion is attributed to the attenuated immune stimulation exerted by self-antigens with high binding affinities, rendering them less effective in eliciting subsequent B-cell maturation and differentiation. Secondly, our refined model places particular emphasis on the crucial role played by somatic hypermutation in modulating the immune system's functionality. Through extensive investigation, we have determined that somatic hypermutation not only expedites the production of highly specific antibodies pivotal in combating microbial infections but also serves as a regulatory mechanism to dampen autoimmunity and enhance self-tolerance within the organism. Lastly, our model advances the understanding of the implications of antibody in vivo evolution in the overall process of organismal aging. With the progression of time, the age-associated amplification of autoimmune activity becomes apparent. While somatic hypermutation effectively delays this process, mitigating the levels of autoimmune response, it falls short of reversing this trajectory entirely. In conclusion, our advanced mathematical model offers a comprehensive and scholarly approach to comprehend the intricacies of the immune system. By encompassing novel mechanisms for selection, emphasizing the functional role of somatic hypermutation, and illuminating the consequences of in vivo antibody evolution, our model expands the current understanding of immune responses and their implications in aging.
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Affiliation(s)
- Zhaobin Xu
- Department of Life Science, Dezhou University, Dezhou 253023, China
| | - Qingzhi Peng
- Department of Life Science, Dezhou University, Dezhou 253023, China
| | - Weidong Liu
- Department of Physical Education, Dezhou University, Dezhou 253023, China
| | - Jacques Demongeot
- Laboratory AGEIS EA 7407, Team Tools for e-Gnosis Medical, Faculty of Medicine, University Grenoble Alpes (UGA), 38700 La Tronche, France
| | - Dongqing Wei
- School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200030, China
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22
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Hao Q, Zhan C, Lian C, Luo S, Cao W, Wang B, Xie X, Ye X, Gui T, Voena C, Pighi C, Wang Y, Tian Y, Wang X, Dai P, Cai Y, Liu X, Ouyang S, Sun S, Hu Q, Liu J, Ye Y, Zhao J, Lu A, Wang JY, Huang C, Su B, Meng FL, Chiarle R, Pan-Hammarström Q, Yeap LS. DNA repair mechanisms that promote insertion-deletion events during immunoglobulin gene diversification. Sci Immunol 2023; 8:eade1167. [PMID: 36961908 PMCID: PMC10351598 DOI: 10.1126/sciimmunol.ade1167] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 03/01/2023] [Indexed: 03/26/2023]
Abstract
Insertions and deletions (indels) are low-frequency deleterious genomic DNA alterations. Despite their rarity, indels are common, and insertions leading to long complementarity-determining region 3 (CDR3) are vital for antigen-binding functions in broadly neutralizing and polyreactive antibodies targeting viruses. Because of challenges in detecting indels, the mechanism that generates indels during immunoglobulin diversification processes remains poorly understood. We carried out ultra-deep profiling of indels and systematically dissected the underlying mechanisms using passenger-immunoglobulin mouse models. We found that activation-induced cytidine deaminase-dependent ±1-base pair (bp) indels are the most prevalent indel events, biasing deleterious outcomes, whereas longer in-frame indels, especially insertions that can extend the CDR3 length, are rare outcomes. The ±1-bp indels are channeled by base excision repair, but longer indels require additional DNA-processing factors. Ectopic expression of a DNA exonuclease or perturbation of the balance of DNA polymerases can increase the frequency of longer indels, thus paving the way for models that can generate antibodies with long CDR3. Our study reveals the mechanisms that generate beneficial and deleterious indels during the process of antibody somatic hypermutation and has implications in understanding the detrimental genomic alterations in various conditions, including tumorigenesis.
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Affiliation(s)
- Qian Hao
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Department of Endocrinology and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Chuanzong Zhan
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Department of Endocrinology and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Chaoyang Lian
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Simin Luo
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Wenyi Cao
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Binbin Wang
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Xia Xie
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences; 320 Yueyang Road, Shanghai 200031, China
| | - Xiaofei Ye
- Department of Biosciences and Nutrition, Karolinska Institutet; SE141-83, Huddinge, Stockholm, Sweden
- Present address: Kindstar Global Precision Medicine Institute, Wuhan, China and Kindstar Biotech, Wuhan, China
| | - Tuantuan Gui
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Claudia Voena
- Department of Molecular Biotechnology and Health Sciences, University of Torino; 10126 Torino, Italy
| | - Chiara Pighi
- Department of Molecular Biotechnology and Health Sciences, University of Torino; 10126 Torino, Italy
- Department of Pathology, Boston Children’s Hospital, and Harvard Medical School; Boston, MA 02115, USA
| | - Yanyan Wang
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences; 320 Yueyang Road, Shanghai 200031, China
| | - Ying Tian
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Xin Wang
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Pengfei Dai
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences; 320 Yueyang Road, Shanghai 200031, China
| | - Yanni Cai
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences; 320 Yueyang Road, Shanghai 200031, China
| | - Xiaojing Liu
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences; 320 Yueyang Road, Shanghai 200031, China
| | - Shengqun Ouyang
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Department of Endocrinology and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Shiqi Sun
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Qianwen Hu
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Jun Liu
- Department of Immunology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Youqiong Ye
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Jingkun Zhao
- Department of General Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Aiguo Lu
- Department of General Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Ji-Yang Wang
- Department of Immunology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
- Department of Microbiology and Immunology, College of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Chuanxin Huang
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Bing Su
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Departments of Endocrinology and Gastroenterology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
- Shanghai Jiao Tong University School of Medicine-Yale Institute for Immune Metabolism, Shanghai Jiao Tong University School of Medicine, Shanghai 200025
| | - Fei-Long Meng
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences; 320 Yueyang Road, Shanghai 200031, China
| | - Roberto Chiarle
- Department of Molecular Biotechnology and Health Sciences, University of Torino; 10126 Torino, Italy
- Department of Pathology, Boston Children’s Hospital, and Harvard Medical School; Boston, MA 02115, USA
| | - Qiang Pan-Hammarström
- Department of Biosciences and Nutrition, Karolinska Institutet; SE141-83, Huddinge, Stockholm, Sweden
| | - Leng-Siew Yeap
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Department of Endocrinology and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
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23
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Sorini C, Tripathi KP, Wu S, Higdon SM, Wang J, Cheng L, Banerjee S, Reinhardt A, Kreslavsky T, Thorell A, Engstrand L, Du J, Villablanca EJ. Metagenomic and single-cell RNA-Seq survey of the Helicobacter pylori-infected stomach in asymptomatic individuals. JCI Insight 2023; 8:161042. [PMID: 36810249 PMCID: PMC9977493 DOI: 10.1172/jci.insight.161042] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 01/11/2023] [Indexed: 02/23/2023] Open
Abstract
Helicobacter pylori colonization of the gastric niche can persist for years in asymptomatic individuals. To deeply characterize the host-microbiota environment in H. pylori-infected (HPI) stomachs, we collected human gastric tissues and performed metagenomic sequencing, single-cell RNA-Seq (scRNA-Seq), flow cytometry, and fluorescent microscopy. HPI asymptomatic individuals had dramatic changes in the composition of gastric microbiome and immune cells compared with noninfected individuals. Metagenomic analysis uncovered pathway alterations related to metabolism and immune response. scRNA-Seq and flow cytometry data revealed that, in contrast to murine stomachs, ILC2s are virtually absent in the human gastric mucosa, whereas ILC3s are the dominant population. Specifically, proportion of NKp44+ ILC3s out of total ILCs were highly increased in the gastric mucosa of asymptomatic HPI individuals, and correlated with the abundance of selected microbial taxa. In addition, CD11c+ myeloid cells and activated CD4+ T cells and B cells were expanded in HPI individuals. B cells of HPI individuals acquired an activated phenotype and progressed into a highly proliferating germinal-center stage and plasmablast maturation, which correlated with the presence of tertiary lymphoid structures within the gastric lamina propria. Our study provides a comprehensive atlas of the gastric mucosa-associated microbiome and immune cell landscape when comparing asymptomatic HPI and uninfected individuals.
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Affiliation(s)
- Chiara Sorini
- Division of Immunology and Allergy, Department of Medicine Solna, Karolinska Institutet and University Hospital, Stockholm, Sweden.,Center of Molecular Medicine, Stockholm, Sweden
| | - Kumar P Tripathi
- Division of Immunology and Allergy, Department of Medicine Solna, Karolinska Institutet and University Hospital, Stockholm, Sweden.,Center of Molecular Medicine, Stockholm, Sweden
| | - Shengru Wu
- Department of Microbiology, Tumor and Cell Biology, Centre for Translational Microbiome Research, Karolinska Institutet, Stockholm, Sweden
| | - Shawn M Higdon
- Department of Microbiology, Tumor and Cell Biology, Centre for Translational Microbiome Research, Karolinska Institutet, Stockholm, Sweden
| | - Jing Wang
- Department of Microbiology, Tumor and Cell Biology, Centre for Translational Microbiome Research, Karolinska Institutet, Stockholm, Sweden
| | - Liqin Cheng
- Department of Microbiology, Tumor and Cell Biology, Centre for Translational Microbiome Research, Karolinska Institutet, Stockholm, Sweden
| | - Sanghita Banerjee
- Division of Immunology and Allergy, Department of Medicine Solna, Karolinska Institutet and University Hospital, Stockholm, Sweden.,Center of Molecular Medicine, Stockholm, Sweden
| | - Annika Reinhardt
- Division of Immunology and Allergy, Department of Medicine Solna, Karolinska Institutet and University Hospital, Stockholm, Sweden.,Center of Molecular Medicine, Stockholm, Sweden
| | - Taras Kreslavsky
- Division of Immunology and Allergy, Department of Medicine Solna, Karolinska Institutet and University Hospital, Stockholm, Sweden.,Center of Molecular Medicine, Stockholm, Sweden
| | | | - Lars Engstrand
- Department of Microbiology, Tumor and Cell Biology, Centre for Translational Microbiome Research, Karolinska Institutet, Stockholm, Sweden
| | - Juan Du
- Department of Microbiology, Tumor and Cell Biology, Centre for Translational Microbiome Research, Karolinska Institutet, Stockholm, Sweden
| | - Eduardo J Villablanca
- Division of Immunology and Allergy, Department of Medicine Solna, Karolinska Institutet and University Hospital, Stockholm, Sweden.,Center of Molecular Medicine, Stockholm, Sweden
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24
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Sible E, Attaway M, Fiorica G, Michel G, Chaudhuri J, Vuong BQ. Ataxia Telangiectasia Mutated and MSH2 Control Blunt DNA End Joining in Ig Class Switch Recombination. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2023; 210:369-376. [PMID: 36603026 PMCID: PMC9915862 DOI: 10.4049/jimmunol.2200590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 12/09/2022] [Indexed: 01/06/2023]
Abstract
Class-switch recombination (CSR) produces secondary Ig isotypes and requires activation-induced cytidine deaminase (AID)-dependent DNA deamination of intronic switch regions within the IgH (Igh) gene locus. Noncanonical repair of deaminated DNA by mismatch repair (MMR) or base excision repair (BER) creates DNA breaks that permit recombination between distal switch regions. Ataxia telangiectasia mutated (ATM)-dependent phosphorylation of AID at serine 38 (pS38-AID) promotes its interaction with apurinic/apyrimidinic endonuclease 1 (APE1), a BER protein, suggesting that ATM regulates CSR through BER. However, pS38-AID may also function in MMR during CSR, although the mechanism remains unknown. To examine whether ATM modulates BER- and/or MMR-dependent CSR, Atm-/- mice were bred to mice deficient for the MMR gene mutS homolog 2 (Msh2). Surprisingly, the predicted Mendelian frequencies of Atm-/-Msh2-/- adult mice were not obtained. To generate ATM and MSH2-deficient B cells, Atm was conditionally deleted on an Msh2-/- background using a floxed ATM allele (Atmf) and B cell-specific Cre recombinase expression (CD23-cre) to produce a deleted ATM allele (AtmD). As compared with AtmD/D and Msh2-/- mice and B cells, AtmD/DMsh2-/- mice and B cells display a reduced CSR phenotype. Interestingly, Sμ-Sγ1 junctions from AtmD/DMsh2-/- B cells that were induced to switch to IgG1 in vitro showed a significant loss of blunt end joins and an increase in insertions as compared with wild-type, AtmD/D, or Msh2-/- B cells. These data indicate that the absence of both ATM and MSH2 blocks nonhomologous end joining, leading to inefficient CSR. We propose a model whereby ATM and MSH2 function cooperatively to regulate end joining during CSR through pS38-AID.
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Affiliation(s)
- Emily Sible
- Biology PhD Program, The Graduate Center, The City University of New York, New York, NY
- Department of Biology, City College of New York, The City University of New York, New York, NY; and
| | - Mary Attaway
- Department of Biology, City College of New York, The City University of New York, New York, NY; and
| | - Giuseppe Fiorica
- Department of Biology, City College of New York, The City University of New York, New York, NY; and
| | - Genesis Michel
- Department of Biology, City College of New York, The City University of New York, New York, NY; and
| | | | - Bao Q. Vuong
- Biology PhD Program, The Graduate Center, The City University of New York, New York, NY
- Department of Biology, City College of New York, The City University of New York, New York, NY; and
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25
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Lacroix M, Beauchemin H, Khandanpour C, Möröy T. The RNA helicase DDX3 and its role in c-MYC driven germinal center-derived B-cell lymphoma. Front Oncol 2023; 13:1148936. [PMID: 37035206 PMCID: PMC10081492 DOI: 10.3389/fonc.2023.1148936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 03/06/2023] [Indexed: 04/11/2023] Open
Abstract
DDX3X is an RNA helicase with many functions in RNA metabolism such as mRNA translation, alternative pre-mRNA splicing and mRNA stability, but also plays a role as a regulator of transcription as well as in the Wnt/beta-catenin- and Nf-κB signaling pathways. The gene encoding DDX3X is located on the X-chromosome, but escapes X-inactivation. Hence females have two active copies and males only one. However, the Y chromosome contains the gene for the male DDX3 homologue, called DDX3Y, which has a very high sequence similarity and functional redundancy with DDX3X, but shows a more restricted protein expression pattern than DDX3X. High throughput sequencing of germinal center (GC)-derived B-cell malignancies such as Burkitt Lymphoma (BL) and Diffuse large B-cell lymphoma (DLBCL) samples showed a high frequency of loss-of-function (LOF) mutations in the DDX3X gene revealing several features that distinguish this gene from others. First, DDX3X mutations occur with high frequency particularly in those GC-derived B-cell lymphomas that also show translocations of the c-MYC proto-oncogene, which occurs in almost all BL and a subset of DLBCL. Second, DDX3X LOF mutations occur almost exclusively in males and is very rarely found in females. Third, mutations in the male homologue DDX3Y have never been found in any type of malignancy. Studies with human primary GC B cells from male donors showed that a loss of DDX3X function helps the initial process of B-cell lymphomagenesis by buffering the proteotoxic stress induced by c-MYC activation. However, full lymphomagenesis requires DDX3 activity since an upregulation of DDX3Y expression is invariably found in GC derived B-cell lymphoma with DDX3X LOF mutation. Other studies with male transgenic mice that lack Ddx3x, but constitutively express activated c-Myc transgenes in B cells and are therefore prone to develop B-cell malignancies, also showed upregulation of the DDX3Y protein expression during the process of lymphomagenesis. Since DDX3Y is not expressed in normal human cells, these data suggest that DDX3Y may represent a new cancer cell specific target to develop adjuvant therapies for male patients with BL and DLBCL and LOF mutations in the DDX3X gene.
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Affiliation(s)
- Marion Lacroix
- Institut de Recherches Cliniques de Montréal, IRCM, Montréal, QC, Canada
- Division of Experimental Medicine, McGill University, Montréal, QC, Canada
| | - Hugues Beauchemin
- Institut de Recherches Cliniques de Montréal, IRCM, Montréal, QC, Canada
| | - Cyrus Khandanpour
- Klinik für Hämatologie und Onkologie, University Hospital Schleswig Holstein, University Lübeck, Lübeck, Germany
- *Correspondence: Tarik Möröy, ; Cyrus Khandanpour,
| | - Tarik Möröy
- Institut de Recherches Cliniques de Montréal, IRCM, Montréal, QC, Canada
- Division of Experimental Medicine, McGill University, Montréal, QC, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, QC, Canada
- *Correspondence: Tarik Möröy, ; Cyrus Khandanpour,
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26
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Rich RR, Cron RQ. The Human Immune Response. Clin Immunol 2023. [DOI: 10.1016/b978-0-7020-8165-1.00001-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/09/2023]
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27
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The transcription factor E2A can bind to and cleave single-stranded immunoglobulin heavy chain locus DNA. Mol Immunol 2023; 153:51-59. [PMID: 36434987 DOI: 10.1016/j.molimm.2022.11.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 11/05/2022] [Accepted: 11/14/2022] [Indexed: 11/24/2022]
Abstract
Class switch recombination (CSR) changes the constant region of the immunoglobulin heavy chain (IgH), and somatic hypermutation (SH) introduces point mutations in the variable regions of the antibody genes. Both these processes that optimize antibody responses of B lymphocytes are initiated by the enzyme Activation Induced cytidine Deaminase (AID). Here we have searched for CSR or SH coupled activities of the transcription factor E2A, since E2A is in a complex with AID and the transcription factors PAX5, ETS1 and IRF4 on key sequences of the Igh locus in B lymphocytes activated to CSR and SH. We report that E2A in contrast to other described transcription factors binds sequence specifically also to single-stranded DNA. The binding of E2A to single-stranded DNA has a strong sequence preference for one strand of a site in the intronic enhancer of the Igh locus. Furthermore, E2A was also found to cleave single-stranded DNA. The sequence profile of substrates cleaved by E2A is coupled to the sequences of substrates and products of AID, suggesting that E2A has a role not only in targeting of AID to switch regions and SH parts of antibody genes but also in cleavage of DNA at these sites.
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28
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Soikkeli AI, Kyläniemi MK, Sihto H, Alinikula J. Oncogenic Merkel Cell Polyomavirus T Antigen Truncating Mutations are Mediated by APOBEC3 Activity in Merkel Cell Carcinoma. CANCER RESEARCH COMMUNICATIONS 2022; 2:1344-1354. [PMID: 36970060 PMCID: PMC10035372 DOI: 10.1158/2767-9764.crc-22-0211] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 08/17/2022] [Accepted: 09/28/2022] [Indexed: 11/06/2022]
Abstract
Merkel cell carcinoma (MCC) is an aggressive skin cancer, which is frequently caused by Merkel cell polyomavirus (MCPyV). Mutations of MCPyV tumor (T) antigens are major pathologic events of virus-positive (MCPyV+) MCCs, but their source is unclear. Activation-induced cytidine deaminase (AID)/APOBEC family cytidine deaminases contribute to antiviral immunity by mutating viral genomes and are potential carcinogenic mutators. We studied the contribution of AID/APOBEC cytidine deaminases to MCPyV large T (LT) truncation events. The MCPyV LT area in MCCs was enriched with cytosine-targeting mutations, and a strong APOBEC3 mutation signature was observed in MCC sequences. AICDA and APOBEC3 expression were detected in the Finnish MCC sample cohort, and LT expression correlated with APOBEC3H and APOBEC3G. Marginal but statistically significant somatic hypermutation targeting activity was detected in the MCPyV regulatory region. Our results suggest that APOBEC3 cytidine deaminases are a plausible cause of the LT truncating mutations in MCPyV+ MCC, while the role of AID in MCC carcinogenesis is unlikely.
Significance:
We uncover APOBEC3 mutation signature in MCPyV LT that reveals the likely cause of mutations underlying MCPyV+ MCC. We further reveal an expression pattern of APOBECs in a large Finnish MCC sample cohort. Thus, the findings presented here suggest a molecular mechanism underlying an aggressive carcinoma with poor prognosis.
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Affiliation(s)
- Anni I. Soikkeli
- 1Unit of Infection and Immunity, Institute of Biomedicine, University of Turku, Turku, Finland
- 2Turku Doctoral Programme of Molecular Medicine, University of Turku, Turku, Finland
| | - Minna K. Kyläniemi
- 3Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland
| | - Harri Sihto
- 4Department of Pathology, University of Helsinki, Helsinki, Finland
| | - Jukka Alinikula
- 1Unit of Infection and Immunity, Institute of Biomedicine, University of Turku, Turku, Finland
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29
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Gómez‐Escolar C, Serrano‐Navarro A, Benguria A, Dopazo A, Sánchez‐Cabo F, Ramiro AR. Single cell clonal analysis identifies an AID-dependent pathway of plasma cell differentiation. EMBO Rep 2022; 23:e55000. [PMID: 36205653 PMCID: PMC9724673 DOI: 10.15252/embr.202255000] [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: 03/08/2022] [Revised: 09/13/2022] [Accepted: 09/15/2022] [Indexed: 11/07/2022] Open
Abstract
Germinal centers (GC) are microstructures where B cells that have been activated by antigen can improve the affinity of their B cell receptors and differentiate into memory B cells (MBCs) or antibody-secreting plasma cells. Here, we have addressed the role of activation-induced deaminase (AID), which initiates somatic hypermutation and class switch recombination, in the terminal differentiation of GC B cells. By combining single cell transcriptome and immunoglobulin clonal analysis in a mouse model that traces AID-experienced cells, we have identified a novel subset of late-prePB cells (L-prePB), which shares the strongest clonal relationships with plasmablasts (PBs). Mice lacking AID have various alterations in the size and expression profiles of transcriptional clusters. We find that AID deficiency leads to a reduced proportion of L-prePB cells and severely impairs transitions between the L-prePB and the PB subsets. Thus, AID shapes the differentiation fate of GC B cells by enabling PB generation from a prePB state.
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Affiliation(s)
- Carmen Gómez‐Escolar
- B Lymphocyte Biology LabCentro Nacional de Investigaciones Cardiovasculares (CNIC)MadridSpain
| | - Alvaro Serrano‐Navarro
- B Lymphocyte Biology LabCentro Nacional de Investigaciones Cardiovasculares (CNIC)MadridSpain
| | - Alberto Benguria
- Genomics UnitCentro Nacional de Investigaciones Cardiovasculares (CNIC)MadridSpain
| | - Ana Dopazo
- Genomics UnitCentro Nacional de Investigaciones Cardiovasculares (CNIC)MadridSpain,CIBER de Enfermedades Cardiovasculares (CIBERCV)MadridSpain
| | - Fátima Sánchez‐Cabo
- Bioinformatics UnitCentro Nacional de Investigaciones Cardiovasculares (CNIC)MadridSpain
| | - Almudena R Ramiro
- B Lymphocyte Biology LabCentro Nacional de Investigaciones Cardiovasculares (CNIC)MadridSpain
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30
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Stewart JA, Bhagwat AS. A redox-sensitive iron-sulfur cluster in murine FAM72A controls its ability to degrade the nuclear form of uracil-DNA glycosylase. DNA Repair (Amst) 2022; 118:103381. [PMID: 35908367 PMCID: PMC10996437 DOI: 10.1016/j.dnarep.2022.103381] [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: 06/03/2022] [Revised: 07/19/2022] [Accepted: 07/25/2022] [Indexed: 11/20/2022]
Abstract
Murine FAM72A, mFAM72A, binds the nuclear form of uracil-DNA glycosylase, mUNG2, inhibits its activity and causes its degradation. In immunoprecipitation assays the human paralog, hFAM72A, binds hUNG2 and is a potential anti-cancer drug target because of its high expression in many cancers. Using purified mFAM72A, and mUNG2 proteins we show that mFAM72A binds mUNG2, and the N-terminal 25 amino acids of mUNG2 bind mFAM72A at a nanomolar dissociation constant. We also show that mFAM72A is present throughout the cells, and mUNG2 helps localize it to nuclei. Based on in silico models of mFAM72A-mUNG2 interactions, we constructed several mutants of mFAM72A and found that while they have reduced ability to deplete mUNG2, the mutations also destabilized the former protein. We confirmed that Withaferin A, a predicted lead molecule for the design of FAM72A inhibitors, binds mFAM72A with micromolar affinity but has little affinity to mUNG2. We identified two potential metal-binding sites in mFAM72A and show that one of the sites contains an Fe-S cluster. This redox-sensitive cluster is involved in the mFAM72A-mUNG2 interaction and modulates mFAM72A activity. Hydrogen peroxide treatment of cells increases mUNG2 depletion in a FAM72A-dependent fashion suggesting that mFAM72A activity is redox-sensitive.
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Affiliation(s)
- Jessica A Stewart
- Department of Chemistry, Wayne State University, Detroit, MI 48202, USA
| | - Ashok S Bhagwat
- Department of Chemistry, Wayne State University, Detroit, MI 48202, USA; Department of Biochemistry, Microbiology and Immunology, Wayne State University School of Medicine, Detroit, MI 48201, USA.
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31
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Peycheva M, Neumann T, Malzl D, Nazarova M, Schoeberl UE, Pavri R. DNA replication timing directly regulates the frequency of oncogenic chromosomal translocations. Science 2022; 377:eabj5502. [DOI: 10.1126/science.abj5502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Chromosomal translocations result from the joining of DNA double-strand breaks (DSBs) and frequently cause cancer. However, the steps linking DSB formation to DSB ligation remain undeciphered. We report that DNA replication timing (RT) directly regulates lymphomagenic
Myc
translocations during antibody maturation in B cells downstream of DSBs and independently of DSB frequency. Depletion of minichromosome maintenance complexes alters replication origin activity, decreases translocations, and deregulates global RT. Ablating a single origin at
Myc
causes an early-to-late RT switch, loss of translocations, and reduced proximity with the immunoglobulin heavy chain (
Igh
) gene, its major translocation partner. These phenotypes were reversed by restoring early RT. Disruption of early RT also reduced tumorigenic translocations in human leukemic cells. Thus, RT constitutes a general mechanism in translocation biogenesis linking DSB formation to DSB ligation.
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Affiliation(s)
- Mihaela Peycheva
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter, 1030 Vienna, Austria
| | - Tobias Neumann
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter, 1030 Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna Biocenter, 1030 Vienna, Austria
| | - Daniel Malzl
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter, 1030 Vienna, Austria
| | - Mariia Nazarova
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter, 1030 Vienna, Austria
| | - Ursula E. Schoeberl
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter, 1030 Vienna, Austria
| | - Rushad Pavri
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter, 1030 Vienna, Austria
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32
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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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33
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França RKADO, Silva JM, Rodrigues LS, Sokolowskei D, Brigido MM, Maranhão AQ. New Anti-Flavivirus Fusion Loop Human Antibodies with Zika Virus-Neutralizing Potential. Int J Mol Sci 2022; 23:ijms23147805. [PMID: 35887153 PMCID: PMC9321016 DOI: 10.3390/ijms23147805] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 07/05/2022] [Accepted: 07/11/2022] [Indexed: 02/04/2023] Open
Abstract
Zika virus infections exhibit recurrent outbreaks and can be responsible for disease complications such as congenital Zika virus syndrome. Effective therapeutic interventions are still a challenge. Antibodies can provide significant protection, although the antibody response may fail due to antibody-dependent enhancement reactions. The choice of the target antigen is a crucial part of the process to generate effective neutralizing antibodies. Human anti-Zika virus antibodies were selected by phage display technology. The antibodies were selected against a mimetic peptide based on the fusion loop region in the protein E of Zika virus, which is highly conserved among different flaviviruses. Four rounds of selection were performed using the synthetic peptide in two strategies: the first was using the acidic elution of bound phages, and the second was by applying a competing procedure. After panning, the selected VH and VL domains were determined by combining NGS and bioinformatic approaches. Three different human monoclonal antibodies were expressed as scFvs and further characterized. All showed a binding capacity to Zika (ZIKV) and showed cross-recognition with yellow fever (YFV) and dengue (DENV) viruses. Two of these antibodies, AZ1p and AZ6m, could neutralize the ZIKV infection in vitro. Due to the conservation of the fusion loop region, these new antibodies can potentially be used in therapeutic intervention against Zika virus and other flavivirus illnesses.
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Affiliation(s)
- Renato Kaylan Alves de Oliveira França
- Molecular Immunology Laboratory, Department of Cellular Biology, Institute of Biological Sciences, University of Brasilia, Brasilia 70910-900, Brazil; (R.K.A.d.O.F.); (J.M.S.); (L.S.R.); (D.S.); (A.Q.M.)
- Graduation Program in Molecular Pathology, University of Brasilia, Brasilia 70910-900, Brazil
| | - Jacyelle Medeiros Silva
- Molecular Immunology Laboratory, Department of Cellular Biology, Institute of Biological Sciences, University of Brasilia, Brasilia 70910-900, Brazil; (R.K.A.d.O.F.); (J.M.S.); (L.S.R.); (D.S.); (A.Q.M.)
| | - Lucas Silva Rodrigues
- Molecular Immunology Laboratory, Department of Cellular Biology, Institute of Biological Sciences, University of Brasilia, Brasilia 70910-900, Brazil; (R.K.A.d.O.F.); (J.M.S.); (L.S.R.); (D.S.); (A.Q.M.)
- Graduation Program in Molecular Pathology, University of Brasilia, Brasilia 70910-900, Brazil
| | - Dimitri Sokolowskei
- Molecular Immunology Laboratory, Department of Cellular Biology, Institute of Biological Sciences, University of Brasilia, Brasilia 70910-900, Brazil; (R.K.A.d.O.F.); (J.M.S.); (L.S.R.); (D.S.); (A.Q.M.)
- Graduation Program in Molecular Biology, University of Brasilia, Brasilia 70910-900, Brazil
| | - Marcelo Macedo Brigido
- Molecular Immunology Laboratory, Department of Cellular Biology, Institute of Biological Sciences, University of Brasilia, Brasilia 70910-900, Brazil; (R.K.A.d.O.F.); (J.M.S.); (L.S.R.); (D.S.); (A.Q.M.)
- Graduation Program in Molecular Pathology, University of Brasilia, Brasilia 70910-900, Brazil
- Graduation Program in Molecular Biology, University of Brasilia, Brasilia 70910-900, Brazil
- III-Immunology Investigation Institute–CNPq-MCT, São Paulo 05403-000, Brazil
- Correspondence:
| | - Andrea Queiroz Maranhão
- Molecular Immunology Laboratory, Department of Cellular Biology, Institute of Biological Sciences, University of Brasilia, Brasilia 70910-900, Brazil; (R.K.A.d.O.F.); (J.M.S.); (L.S.R.); (D.S.); (A.Q.M.)
- Graduation Program in Molecular Pathology, University of Brasilia, Brasilia 70910-900, Brazil
- Graduation Program in Molecular Biology, University of Brasilia, Brasilia 70910-900, Brazil
- III-Immunology Investigation Institute–CNPq-MCT, São Paulo 05403-000, Brazil
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34
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Inflammation accelerates BCR-ABL1+ B-ALL development through upregulation of AID. Blood Adv 2022; 6:4060-4072. [PMID: 35816360 PMCID: PMC9278295 DOI: 10.1182/bloodadvances.2021005017] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 05/03/2022] [Indexed: 11/20/2022] Open
Abstract
Inflammatory stimulation promotes BCR-ABL1+ B-ALL disease progression by upregulating AID. Combination of imatinib and Hsp90 inhibitors significantly delays the inflammation-induced progression of BCR-ABL1+ B-ALL.
Inflammation contributes to the initiation and disease progression of several lymphoid malignancies. BCR-ABL1-positive B-cell acute lymphoblastic leukemia (BCR-ABL1+ B-ALL) is triggered by the malignant cloning of immature B cells promoted by the BCR-ABL1 fusion gene. However, it is unclear whether the mechanism driving the disease progression of BCR-ABL1+ B-ALL involves inflammatory stimulation. Here, we evaluate BCR-ABL1+ B-ALL cells’ response to inflammatory stimuli lipopolysaccharide (LPS) in vitro and in vivo. The results indicate that LPS promotes cell growth and genomic instability in cultured BCR-ABL1+ B-ALL cells and accelerates the BCR-ABL1+ B-ALL development in a mouse model. We show that the LPS-induced upregulation of activation-induced deaminase (AID) is required for the cell growth and disease progression of BCR-ABL1+ B-ALL. Moreover, AID modulates the expression of various genes that are dominated by suppressing apoptosis genes and upregulating DNA damage-repair genes. These genes lead to facilitation for BCR-ABL1+ B-ALL progression. The heat shock protein 90 (Hsp90) inhibitors significantly reduce AID protein level and delay the disease progression of BCR-ABL1+ B-ALL upon inflammatory stimulation. The present data demonstrate the causative role of AID in the development and progression of BCR-ABL1+ B-ALL during inflammation, thus highlighting potential therapeutic targets.
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35
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Liu B, Li Z. PTIP-Associated Protein 1: More Than a Component of the MLL3/4 Complex. Front Genet 2022; 13:889109. [PMID: 35754824 PMCID: PMC9219552 DOI: 10.3389/fgene.2022.889109] [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: 03/03/2022] [Accepted: 04/21/2022] [Indexed: 11/13/2022] Open
Abstract
PTIP-associated protein 1 (PA1) is a unique component of MLL3/4 complexes, which are important mammalian histone 3 lysine 4 (H3K4) methyltransferases. PA1 has generated research interest due to its involvement in many essential biological processes such as adipogenesis, B cell class switch recombination, spermatogenesis, and embryonic development. In addition to the classical role of PA1 in H3K4 methylation, non-classical functions have also been discovered in recent studies. In this review, we systematically summarize the expression pattern of PA1 protein in humans and sort the specific molecular mechanism of PA1 in various biological processes. Meanwhile, we provide some new perspectives on the role of PA1 for future studies. A comprehensive understanding of the biological functions and molecular mechanisms of PA1 will facilitate the investigation of its complicated roles in transcriptional regulation.
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Affiliation(s)
- Bo Liu
- Department of Human Anatomy, Histology and Embryology, the Fourth Military Medical University, Xi'an, China
| | - Zhen Li
- Department of Human Anatomy, Histology and Embryology, the Fourth Military Medical University, Xi'an, China
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36
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Ou BS, Saouaf OM, Baillet J, Appel EA. Sustained delivery approaches to improving adaptive immune responses. Adv Drug Deliv Rev 2022; 187:114401. [PMID: 35750115 DOI: 10.1016/j.addr.2022.114401] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Revised: 06/14/2022] [Accepted: 06/17/2022] [Indexed: 11/17/2022]
Abstract
The immune system is one of the most important, complex biological networks regulating and protecting human health. Its precise modulation can prevent deadly infections and fight cancer. Accordingly, prophylactic vaccines and cancer immunotherapies are some of the most powerful technologies to protect against potential dangers through training of the immune system. Upon immunization, activation and maturation of B and T cells of the adaptive immune system are necessary for development of proper humoral and cellular protection. Yet, the exquisite organization of the immune system requires spatiotemporal control over the exposure of immunomodulatory signals. For example, while the human immune system has evolved to develop immunity to natural pathogenic infections that often last for weeks, current prophylactic vaccination technologies only expose the immune system to immunomodulatory signals for hours to days. It has become clear that leveraging sustained release technologies to prolong immunogen and adjuvant exposure can increase the potency, durability, and quality of adaptive immune responses. Over the past several years, tremendous breakthroughs have been made in the design of novel biomaterials such as nanoparticles, microparticles, hydrogels, and microneedles that can precisely control and the presentation of immunomodulatory signals to the immune system. In this review, we discuss relevant sustained release strategies and their corresponding benefits to cellular and humoral responses.
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Affiliation(s)
- Ben S Ou
- Department of Bioengineering, Stanford University, Stanford 94305, USA
| | - Olivia M Saouaf
- Department of Materials Science & Engineering, Stanford University, Stanford 94305, USA
| | - Julie Baillet
- Department of Materials Science & Engineering, Stanford University, Stanford 94305, USA; University of Bordeaux, CNRS, Bordeaux INP, LCPO, UMR 5629, Pessac 33600, France
| | - Eric A Appel
- Department of Bioengineering, Stanford University, Stanford 94305, USA; Department of Materials Science & Engineering, Stanford University, Stanford 94305, USA; Department of Pediatrics (Endocrinology), Stanford University, Stanford 94305, USA; ChEM-H Institute, Stanford University, Stanford CA 94305, USA; Woods Institute for the Environment, Stanford University, Stanford, CA 94305, USA.
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37
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Abstract
Activation-induced cytidine deaminase (AID) initiates somatic hypermutation of immunoglobulin (Ig) gene variable regions and class switch recombination (CSR) of Ig heavy chain constant regions. Two decades of intensive research has greatly expanded our knowledge of how AID functions in peripheral B cells to optimize antibody responses against infections, while maintaining tight regulation of AID to restrain its activity to protect B cell genomic integrity. The many exciting recent advances in the field include: 1) the first description of AID's molecular structure, 2) remarkable advances in high throughput approaches that precisely track AID targeting genome-wide, and 3) the discovery that the cohesion-mediate loop extrusion mechanism [initially discovered in V(D)J recombination studies] also governs AID-medicated CSR. These advances have significantly advanced our understanding of AID's biochemical properties in vitro and AID's function and regulation in vivo. This mini review will discuss these recent discoveries and outline the challenges and questions that remain to be addressed.
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38
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Contribution of rare mutational outcomes to broadly neutralizing antibodies. Acta Biochim Biophys Sin (Shanghai) 2022; 54:820-827. [PMID: 35713319 PMCID: PMC9828561 DOI: 10.3724/abbs.2022065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Antibodies are important immune molecules that are elicited by B cells to protect our bodies during viral infections or vaccinations. In humans, the antibody repertoire is diversified by programmed DNA lesion processes to ensure specific and high affinity binding to various antigens. Broadly neutralizing antibodies (bnAbs) are antibodies that have strong neutralizing activities against different variants of a virus. bnAbs such as anti-HIV bnAbs often have special characteristics including insertions and deletions, long complementarity determining region 3 (CDR3), and high frequencies of mutations, often at improbable sites of the variable regions. These unique features are rare mutational outcomes that are acquired during antibody diversification processes. In this review, we will discuss possible mechanisms that generate these rare antibody mutational outcomes. The understanding of the mechanisms that generate these rare mutational outcomes during antibody diversification will have implications in vaccine design strategies to elicit bnAbs.
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39
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Laffleur B, Batista CR, Zhang W, Lim J, Yang B, Rossille D, Wu L, Estrella J, Rothschild G, Pefanis E, Basu U. RNA exosome drives early B cell development via noncoding RNA processing mechanisms. Sci Immunol 2022; 7:eabn2738. [PMID: 35658015 DOI: 10.1126/sciimmunol.abn2738] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
B cell development is linked to successful V(D)J recombination, allowing B cell receptor expression and ultimately antibody secretion for adaptive immunity. Germline noncoding RNAs (ncRNAs) are produced at immunoglobulin (Ig) loci during V(D)J recombination, but their function and posttranscriptional regulation are incompletely understood. Patients with trichohepatoenteric syndrome, characterized by RNA exosome pathway component mutations, exhibit lymphopenia, thus demonstrating the importance of ncRNA surveillance in B cell development in humans. To understand the role of RNA exosome in early B cell development in greater detail, we generated mouse models harboring a B cell-specific cre allele (Mb1cre), coupled to conditional inversion-deletion alleles of one RNA exosome core component (Exosc3) or RNase catalytic subunits (Exosc10 or Dis3). We noticed increased expression of RNA exosome subunits during V(D)J recombination, whereas a B cell developmental blockade at the pro-B cell stage was observed in the different knockout mice, overlapping with a lack of productive rearrangements of VDJ genes at the Ig heavy chain (Igh). This unsuccessful recombination prevented differentiation into pre-B cells, with accumulation of ncRNAs and up-regulation of the p53 pathway. Introduction of a prearranged Igh VDJ allele partly rescued the pre-B cell population in Dis3-deficient cells, although V-J recombination defects were observed at Ig light chain kappa (Igκ), preventing subsequent B cell development. These observations demonstrated that the RNA exosome complex is important for Igh and Igκ recombination and establish the relevance of RNA processing for optimal diversification at these loci during B cell development.
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Affiliation(s)
- Brice Laffleur
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Carolina R Batista
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Wanwei Zhang
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Junghyun Lim
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Biao Yang
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Delphine Rossille
- Universite of Rennes, INSERM, EFS Bretagne, CHU Rennes, UMR 1236, Rennes, France
| | - Lijing Wu
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Jerson Estrella
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Gerson Rothschild
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | | | - Uttiya Basu
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
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40
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Heeb SR, Schaller M, Kremer Hovinga JA. Naturally Occurring Anti-Idiotypic Antibodies Portray a Largely Private Repertoire in Immune-Mediated Thrombotic Thrombocytopenic Purpura. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2022; 208:2497-2507. [PMID: 35589126 DOI: 10.4049/jimmunol.2100868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 03/29/2022] [Indexed: 12/30/2022]
Abstract
Rare immune-mediated thrombotic thrombocytopenic purpura (iTTP) is a life-threatening disease resulting from a severe autoantibody-mediated ADAMTS13 (a disintegrin and metalloprotease with thrombospondin type 1 motifs, member 13) deficiency. Acute iTTP episodes are medical emergencies, but when treated appropriately &gt;95% of patients survive. However, at least half of survivors will eventually experience a relapse. How remission of an initial episode is achieved and factors contributing to reemergence of anti-ADAMTS13 Abs and a relapsing course are poorly understood. In acquired hemophilia and systemic lupus erythematosus, anti-idiotypic Abs counteracting and neutralizing pathogenic autoantibodies contribute to remission. We selected and amplified the splenic anti-idiotypic IgG<sub>1</sub> Fab κ/λ repertoire of two relapsing iTTP patients on previously generated monoclonal inhibitory anti-ADAMTS13 Fabs by phage display to explore whether anti-idiotypic Abs have a role in iTTP. We obtained 27 single anti-idiotypic Fab clones, half of which had unique sequences, although both patients shared four H chain V region genes (V<sub>H</sub>1-69*01, V<sub>H</sub>3-15*01, V<sub>H</sub>3-23*01, and V<sub>H</sub>3-49*03). Anti-idiotypic Fab pools of both patients fully neutralized the inhibitor capacity of the monoclonal anti-ADAMTS13 Abs used for their selection. Preincubation of plasma samples of 22 unrelated iTTP patients stratified according to functional ADAMTS13 inhibitor titers (&gt;2 Bethesda units/ml, or 1-2 Bethesda units/ml), with anti-idiotypic Fab pools neutralized functional ADAMTS13 inhibitors and restored ADAMTS13 activity in 18-45% of those cases. Taken together, we present evidence for the presence of an anti-idiotypic immune response in iTTP patients. The interindividual generalizability of this response is limited despite relatively uniform pathogenic anti-ADAMTS13 Abs recognizing a dominant epitope in the ADAMTS13 spacer domain.
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Affiliation(s)
- Silvan R Heeb
- Department of Hematology and Central Hematology Laboratory, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; and Department for BioMedical Research, University of Bern, Bern, Switzerland
| | - Monica Schaller
- Department of Hematology and Central Hematology Laboratory, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; and Department for BioMedical Research, University of Bern, Bern, Switzerland
| | - Johanna A Kremer Hovinga
- Department of Hematology and Central Hematology Laboratory, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; and Department for BioMedical Research, University of Bern, Bern, Switzerland
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41
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Gelmez MY, Betul Oktelik F, Cinar S, Ozbalak M, Ozluk O, Aktan M, Deniz G. High expression of OX-40, ICOS, and low expression PD-L1 of follicular helper and follicular cytotoxic T cells in chronic lymphocytic leukemia. J Hematop 2022. [DOI: 10.1007/s12308-022-00497-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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42
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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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43
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Lei T, Du S, Peng Z, Chen L. Multifaceted regulation and functions of 53BP1 in NHEJ‑mediated DSB repair (Review). Int J Mol Med 2022; 50:90. [PMID: 35583003 PMCID: PMC9162042 DOI: 10.3892/ijmm.2022.5145] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Accepted: 04/29/2022] [Indexed: 12/02/2022] Open
Abstract
The repair of DNA double-strand breaks (DSBs) is crucial for the preservation of genomic integrity and the maintenance of cellular homeostasis. Non-homologous DNA end joining (NHEJ) is the predominant repair mechanism for any type of DNA DSB during the majority of the cell cycle. NHEJ defects regulate tumor sensitivity to ionizing radiation and anti-neoplastic agents, resulting in immunodeficiencies and developmental abnormalities in malignant cells. p53-binding protein 1 (53BP1) is a key mediator involved in DSB repair, which functions to maintain a balance in the repair pathway choices and in preserving genomic stability. 53BP1 promotes DSB repair via NHEJ and antagonizes DNA end overhang resection. At present, novel lines of evidence have revealed the molecular mechanisms underlying the recruitment of 53BP1 and DNA break-responsive effectors to DSB sites, and the promotion of NHEJ-mediated DSB repair via 53BP1, while preventing homologous recombination. In the present review article, recent advances made in the elucidation of the structural and functional characteristics of 53BP1, the mechanisms of 53BP1 recruitment and interaction with the reshaping of the chromatin architecture around DSB sites, the post-transcriptional modifications of 53BP1, and the up- and downstream pathways of 53BP1 are discussed. The present review article also focuses on the application perspectives, current challenges and future directions of 53BP1 research.
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Affiliation(s)
- Tiantian Lei
- Department of Pharmacy, Women and Children's Hospital of Chongqing Medical University, Chongqing 401147, P.R. China
| | - Suya Du
- Department of Clinical Pharmacy, Sichuan Cancer Hospital and Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan 610041, P.R. China
| | - Zhe Peng
- Department of Pharmacy, Women and Children's Hospital of Chongqing Medical University, Chongqing 401147, P.R. China
| | - Lin Chen
- Department of Pharmacy, Women and Children's Hospital of Chongqing Medical University, Chongqing 401147, P.R. China
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Balasubramanian S, Andreani M, Andrade JG, Saha T, Sundaravinayagam D, Garzón J, Zhang W, Popp O, Hiraga SI, Rahjouei A, Rosen DB, Mertins P, Chait BT, Donaldson AD, Di Virgilio M. Protection of nascent DNA at stalled replication forks is mediated by phosphorylation of RIF1 intrinsically disordered region. eLife 2022; 11:e75047. [PMID: 35416772 PMCID: PMC9007588 DOI: 10.7554/elife.75047] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 03/30/2022] [Indexed: 12/22/2022] Open
Abstract
RIF1 is a multifunctional protein that plays key roles in the regulation of DNA processing. During repair of DNA double-strand breaks (DSBs), RIF1 functions in the 53BP1-Shieldin pathway that inhibits resection of DNA ends to modulate the cellular decision on which repair pathway to engage. Under conditions of replication stress, RIF1 protects nascent DNA at stalled replication forks from degradation by the DNA2 nuclease. How these RIF1 activities are regulated at the post-translational level has not yet been elucidated. Here, we identified a cluster of conserved ATM/ATR consensus SQ motifs within the intrinsically disordered region (IDR) of mouse RIF1 that are phosphorylated in proliferating B lymphocytes. We found that phosphorylation of the conserved IDR SQ cluster is dispensable for the inhibition of DSB resection by RIF1, but is essential to counteract DNA2-dependent degradation of nascent DNA at stalled replication forks. Therefore, our study identifies a key molecular feature that enables the genome-protective function of RIF1 during DNA replication stress.
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Affiliation(s)
- Sandhya Balasubramanian
- Laboratory of Genome Diversification & Integrity, Max Delbrück Center for Molecular Medicine in the Helmholtz AssociationBerlinGermany
- Freie Universität BerlinBerlinGermany
| | - Matteo Andreani
- Laboratory of Genome Diversification & Integrity, Max Delbrück Center for Molecular Medicine in the Helmholtz AssociationBerlinGermany
- Freie Universität BerlinBerlinGermany
| | - Júlia Goncalves Andrade
- Laboratory of Genome Diversification & Integrity, Max Delbrück Center for Molecular Medicine in the Helmholtz AssociationBerlinGermany
| | - Tannishtha Saha
- Laboratory of Genome Diversification & Integrity, Max Delbrück Center for Molecular Medicine in the Helmholtz AssociationBerlinGermany
- Freie Universität BerlinBerlinGermany
| | - Devakumar Sundaravinayagam
- Laboratory of Genome Diversification & Integrity, Max Delbrück Center for Molecular Medicine in the Helmholtz AssociationBerlinGermany
| | - Javier Garzón
- Institute of Medical Sciences, University of Aberdeen, ForesterhillAberdeenUnited Kingdom
| | - Wenzhu Zhang
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller UniversityNew YorkUnited States
| | - Oliver Popp
- Proteomics Platform, Max Delbrück Center for Molecular Medicine in the Helmholtz Association and Berlin Institute of HealthBerlinGermany
| | - Shin-ichiro Hiraga
- Institute of Medical Sciences, University of Aberdeen, ForesterhillAberdeenUnited Kingdom
| | - Ali Rahjouei
- Laboratory of Genome Diversification & Integrity, Max Delbrück Center for Molecular Medicine in the Helmholtz AssociationBerlinGermany
| | - Daniel B Rosen
- Laboratory of Molecular Immunology, The Rockefeller UniversityNew YorkUnited States
| | - Philipp Mertins
- Proteomics Platform, Max Delbrück Center for Molecular Medicine in the Helmholtz Association and Berlin Institute of HealthBerlinGermany
| | - Brian T Chait
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller UniversityNew YorkUnited States
| | - Anne D Donaldson
- Institute of Medical Sciences, University of Aberdeen, ForesterhillAberdeenUnited Kingdom
| | - Michela Di Virgilio
- Laboratory of Genome Diversification & Integrity, Max Delbrück Center for Molecular Medicine in the Helmholtz AssociationBerlinGermany
- Charité-Universitätsmedizin BerlinBerlinGermany
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45
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Gullickson P, Xu YW, Niedernhofer LJ, Thompson EL, Yousefzadeh MJ. The Role of DNA Repair in Immunological Diversity: From Molecular Mechanisms to Clinical Ramifications. Front Immunol 2022; 13:834889. [PMID: 35432317 PMCID: PMC9010869 DOI: 10.3389/fimmu.2022.834889] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 03/02/2022] [Indexed: 12/18/2022] Open
Abstract
An effective humoral immune response necessitates the generation of diverse and high-affinity antibodies to neutralize pathogens and their products. To generate this assorted immune repertoire, DNA damage is introduced at specific regions of the genome. Purposeful genotoxic insults are needed for the successful completion of multiple immunological diversity processes: V(D)J recombination, class-switch recombination, and somatic hypermutation. These three processes, in concert, yield a broad but highly specific immune response. This review highlights the importance of DNA repair mechanisms involved in each of these processes and the catastrophic diseases that arise from DNA repair deficiencies impacting immune system function. These DNA repair disorders underline not only the importance of maintaining genomic integrity for preventing disease but also for robust adaptive immunity.
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46
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Wu L, Shukla V, Yadavalli AD, Dinesh RK, Xu D, Rao A, Schatz DG. HMCES protects immunoglobulin genes specifically from deletions during somatic hypermutation. Genes Dev 2022; 36:433-450. [PMID: 35450882 PMCID: PMC9067407 DOI: 10.1101/gad.349438.122] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 03/29/2022] [Indexed: 01/07/2023]
Abstract
Somatic hypermutation (SHM) produces point mutations in immunoglobulin (Ig) genes in B cells when uracils created by the activation-induced deaminase are processed in a mutagenic manner by enzymes of the base excision repair (BER) and mismatch repair (MMR) pathways. Such uracil processing creates DNA strand breaks and is susceptible to the generation of deleterious deletions. Here, we demonstrate that the DNA repair factor HMCES strongly suppresses deletions without significantly affecting other parameters of SHM in mouse and human B cells, thereby facilitating the production of antigen-specific antibodies. The deletion-prone repair pathway suppressed by HMCES operates downstream from the uracil glycosylase UNG and is mediated by the combined action of BER factor APE2 and MMR factors MSH2, MSH6, and EXO1. HMCES's ability to shield against deletions during SHM requires its capacity to form covalent cross-links with abasic sites, in sharp contrast to its DNA end-joining role in class switch recombination but analogous to its genome-stabilizing role during DNA replication. Our findings lead to a novel model for the protection of Ig gene integrity during SHM in which abasic site cross-linking by HMCES intercedes at a critical juncture during processing of vulnerable gapped DNA intermediates by BER and MMR enzymes.
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Affiliation(s)
- Lizhen Wu
- Department of Immunobiology, Yale School of Medicine, New Haven, Connecticut 06520, USA
| | - Vipul Shukla
- Division of Signaling and Gene Expression, La Jolla Institute for Immunology, La Jolla, California 92037, USA
| | | | - Ravi K Dinesh
- Department of Immunobiology, Yale School of Medicine, New Haven, Connecticut 06520, USA
| | - Dijin Xu
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Anjana Rao
- Division of Signaling and Gene Expression, La Jolla Institute for Immunology, La Jolla, California 92037, USA
- Department of Pharmacology, Moores Cancer Center, University of California at San Diego, La Jolla, California 92093, USA
- Consortium for Regenerative Medicine, La Jolla, California 92037, USA
| | - David G Schatz
- Department of Immunobiology, Yale School of Medicine, New Haven, Connecticut 06520, USA
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Abstract
Purpose of review Immunological memory is an important evolutionary adaptation of the immune system. Previously restricted to the adaptive immune system, the concept of memory has recently been broadened to the innate immune system. This review summarizes recent studies that highlight the contribution of the hematopoietic stem cells (HSCs) in supporting immunological memory. Recent findings Short-lived innate immune cells can build a long-lasting memory of infection to improve their response to secondary challenges. Studies show that these unexpected properties of the innate immune system are sustained by epigenetic and metabolic changes in the HSC compartment. Summary HSCs are durably altered in response to pathogens and serve as long-term support for innate immune memory. Many questions remain regarding the mechanisms contributing to the induction and the maintenance of this immune memory in HSCs. Answering these questions will open new perspectives to understand how environmental factors shape the HSC activity over time.
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48
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Fleming A, Castro‐Dopico T, Clatworthy MR. B cell class switching in intestinal immunity in health and disease. Scand J Immunol 2022; 95:e13139. [PMID: 34978077 PMCID: PMC9285483 DOI: 10.1111/sji.13139] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 12/31/2021] [Accepted: 12/31/2021] [Indexed: 12/12/2022]
Abstract
The gastrointestinal tract is colonized by trillions of commensal microorganisms that collectively form the microbiome and make essential contributions to organism homeostasis. The intestinal immune system must tolerate these beneficial commensals, whilst preventing pathogenic organisms from systemic spread. Humoral immunity plays a key role in this process, with large quantities of immunoglobulin (Ig)A secreted into the lumen on a daily basis, regulating the microbiome and preventing bacteria from encroaching on the epithelium. However, there is an increasing appreciation of the role of IgG antibodies in intestinal immunity, including beneficial effects in neonatal immune development, pathogen and tumour resistance, but also of pathological effects in driving chronic inflammation in inflammatory bowel disease (IBD). These antibody isotypes differ in effector function, with IgG exhibiting more proinflammatory capabilities compared with IgA. Therefore, the process that leads to the generation of different antibody isotypes, class-switch recombination (CSR), requires careful regulation and is orchestrated by the immunological cues generated by the prevalent local challenge. In general, an initiating signal such as CD40 ligation on B cells leads to the induction of activation-induced cytidine deaminase (AID), but a second cytokine-mediated signal determines which Ig heavy chain is expressed. Whilst the cytokines driving intestinal IgA responses are well-studied, there is less clarity on how IgG responses are generated in the intestine, and how these cues might become dysfunctional in IBD. Here, we review the key mechanisms regulating class switching to IgA vs IgG in the intestine, processes that could be therapeutically manipulated in infection and IBD.
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Affiliation(s)
- Aaron Fleming
- Molecular Immunity UnitDepartment of MedicineCambridge Institute of Therapeutic Immunology and Infectious DiseasesUniversity of CambridgeCambridgeUK
| | - Tomas Castro‐Dopico
- Molecular Immunity UnitDepartment of MedicineCambridge Institute of Therapeutic Immunology and Infectious DiseasesUniversity of CambridgeCambridgeUK
- The Francis Crick InstituteLondonUK
| | - Menna R. Clatworthy
- Molecular Immunity UnitDepartment of MedicineCambridge Institute of Therapeutic Immunology and Infectious DiseasesUniversity of CambridgeCambridgeUK
- Cellular GeneticsWellcome Trust Sanger InstituteHinxtonUK
- NIHR Cambridge Biomedical Research CentreCambridgeUK
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49
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Tang C, Krantsevich A, MacCarthy T. Deep learning model of somatic hypermutation reveals importance of sequence context beyond hotspot targeting. iScience 2022; 25:103668. [PMID: 35036866 PMCID: PMC8749460 DOI: 10.1016/j.isci.2021.103668] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 11/08/2021] [Accepted: 12/16/2021] [Indexed: 11/23/2022] Open
Abstract
B cells undergo somatic hypermutation (SHM) of the Immunoglobulin (Ig) variable region to generate high-affinity antibodies. SHM relies on the activity of activation-induced deaminase (AID), which mutates C>U preferentially targeting WRC (W=A/T, R=A/G) hotspots. Downstream mutations at WA Polymerase η hotspots contribute further mutations. Computational models of SHM can describe the probability of mutations essential for vaccine responses. Previous studies using short subsequences (k-mers) failed to explain divergent mutability for the same k-mer. We developed the DeepSHM (Deep learning on SHM) model using k-mers of size 5-21, improving accuracy over previous models. Interpretation of DeepSHM identified an extended WWRCT motif with particularly high mutability. Increased mutability was further associated with lower surrounding G content. Our model also discovered a conserved AGYCTGGGGG (Y=C/T) motif within FW1 of IGHV3 family genes with unusually high T>G substitution rates. Thus, a wider sequence context increases predictive power and identifies features that drive mutational targeting.
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Affiliation(s)
- Catherine Tang
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, NY 11794, USA
| | - Artem Krantsevich
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, NY 11794, USA
| | - Thomas MacCarthy
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, NY 11794, USA
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, NY 11794, USA
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50
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Roth GA, Picece VCTM, Ou BS, Luo W, Pulendran B, Appel EA. Designing spatial and temporal control of vaccine responses. NATURE REVIEWS. MATERIALS 2022; 7:174-195. [PMID: 34603749 PMCID: PMC8477997 DOI: 10.1038/s41578-021-00372-2] [Citation(s) in RCA: 125] [Impact Index Per Article: 62.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/08/2021] [Indexed: 05/02/2023]
Abstract
Vaccines are the key technology to combat existing and emerging infectious diseases. However, increasing the potency, quality and durability of the vaccine response remains a challenge. As our knowledge of the immune system deepens, it becomes clear that vaccine components must be in the right place at the right time to orchestrate a potent and durable response. Material platforms, such as nanoparticles, hydrogels and microneedles, can be engineered to spatially and temporally control the interactions of vaccine components with immune cells. Materials-based vaccination strategies can augment the immune response by improving innate immune cell activation, creating local inflammatory niches, targeting lymph node delivery and controlling the time frame of vaccine delivery, with the goal of inducing enhanced memory immunity to protect against future infections. In this Review, we highlight the biological mechanisms underlying strong humoral and cell-mediated immune responses and explore materials design strategies to manipulate and control these mechanisms.
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Affiliation(s)
- Gillie A. Roth
- Department of Bioengineering, Stanford University, Stanford, CA USA
| | - Vittoria C. T. M. Picece
- Department of Materials Science & Engineering, Stanford University, Stanford, CA USA
- Department of Chemistry and Applied Biosciences, ETH Zürich, Zürich, Switzerland
| | - Ben S. Ou
- Department of Bioengineering, Stanford University, Stanford, CA USA
| | - Wei Luo
- Institute for Immunity, Transplantation & Infection, Stanford University School of Medicine, Stanford, CA USA
| | - Bali Pulendran
- Institute for Immunity, Transplantation & Infection, Stanford University School of Medicine, Stanford, CA USA
- ChEM-H Institute, Stanford University, Stanford, CA USA
- Department of Microbiology & Immunology, Stanford University School of Medicine, Stanford, CA USA
- Program in Immunology, Stanford University School of Medicine, Stanford, CA USA
- Department of Pathology, Stanford University School of Medicine, Stanford, CA USA
| | - Eric A. Appel
- Department of Bioengineering, Stanford University, Stanford, CA USA
- Department of Materials Science & Engineering, Stanford University, Stanford, CA USA
- ChEM-H Institute, Stanford University, Stanford, CA USA
- Department of Paediatrics — Endocrinology, Stanford University School of Medicine, Stanford, CA USA
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