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Li S, Liu W, Li Y, Zhao S, Liu C, Hu M, Yue W, Liu Y, Wang Y, Yang R, Xiang R, Liu F. Contribution of secondary Igkappa rearrangement to primary immunoglobulin repertoire diversification. Mol Immunol 2016; 78:193-206. [PMID: 27665270 DOI: 10.1016/j.molimm.2016.09.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 09/01/2016] [Accepted: 09/06/2016] [Indexed: 10/21/2022]
Abstract
Abs reactive to DNA and DNA/histone complexes are a distinguished characteristic of primary immunoglobulin repertoires in autoimmune B6.MRL-Faslpr and MRL/MpJ-Faslpr mice. These mice are defective in Fas receptor, which is critical for the apoptosis of autoreactive B cells by an extrinsic pathway. In the present study, we explored the possibility that bone marrow small pre-B and immature B cells from adult B6.MRL-Faslpr mice and MRL/MpJ-Faslpr mice respectively, which contain autoreactive B-cell antigen receptors (BCR) and manifest autoimmune syndromes, exhibit enhanced receptor editing patterns. Indeed, FASlpr pre B and immature B cells were shown to possess more ongoing replacements of non-productive (nP) than productive (P) primary VκJκ rearrangements. Significantly, the P vs nP ratios of these replaced primary rearrangements were 1:2, thus indicating that κ light-chain production appears not to inhibit secondary rearrangements. In addition, we identified multiple atypical rearrangements, such as Vκ cRS (cryptic recombination signals) cleavages. These results suggest that the onset of light chain secondary rearrangements persists similarly as a non-selected mode and independent of BCR autoreactivity during certain developmental windows of bone marrow B cells in lupus-prone mice and control, and leads us to propose the function of secondary, de novo Igκ rearrangements to increase BCR diversity.
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Affiliation(s)
- Shufang Li
- Department of Immunology, School of Medicine, Nankai University, Tianjin 300071, China
| | - Wei Liu
- Tianjin Entry-Exit Inspection and Quarantine Bureau, Tianjin 300308, China
| | - Yinghui Li
- Department of Immunology, School of Medicine, Nankai University, Tianjin 300071, China
| | - Shaorong Zhao
- Department of Immunology, School of Medicine, Nankai University, Tianjin 300071, China
| | - Can Liu
- Department of Immunology, School of Medicine, Nankai University, Tianjin 300071, China
| | - Mengyun Hu
- Collage of Life Science, Nankai University, Tianjin, 300071, China
| | - Wei Yue
- Department of Neurology, Huanhu Hospital, Tianjin 300060, China
| | - Yanhua Liu
- Department of Immunology, School of Medicine, Nankai University, Tianjin 300071, China
| | - Yue Wang
- Department of Immunology, School of Medicine, Nankai University, Tianjin 300071, China
| | - Rongcun Yang
- Department of Immunology, School of Medicine, Nankai University, Tianjin 300071, China
| | - Rong Xiang
- Department of Immunology, School of Medicine, Nankai University, Tianjin 300071, China.
| | - Feifei Liu
- Department of Immunology, School of Medicine, Nankai University, Tianjin 300071, China.
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Iacoangeli A, Lui A, Naik U, Ohta Y, Flajnik M, Hsu E. Biased Immunoglobulin Light Chain Gene Usage in the Shark. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2015; 195:3992-4000. [PMID: 26342033 PMCID: PMC4592821 DOI: 10.4049/jimmunol.1501426] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 08/04/2015] [Indexed: 12/13/2022]
Abstract
This study of a large family of κ L chain clusters in nurse shark completes the characterization of its classical Ig gene content (two H chain isotypes, μ and ω, and four L chain isotypes, κ, λ, σ, and σ-2). The shark κ clusters are minigenes consisting of a simple VL-JL-CL array, where V to J recombination occurs over an ~500-bp interval, and functional clusters are widely separated by at least 100 kb. Six out of ~39 κ clusters are prerearranged in the germline (germline joined). Unlike the complex gene organization and multistep assembly process of Ig in mammals, each shark Ig rearrangement, somatic or in the germline, appears to be an independent event localized to the minigene. This study examined the expression of functional, nonproductive, and sterile transcripts of the κ clusters compared with the other three L chain isotypes. κ cluster usage was investigated in young sharks, and a skewed pattern of split gene expression was observed, one similar in functional and nonproductive rearrangements. These results show that the individual activation of the spatially distant κ clusters is nonrandom. Although both split and germline-joined κ genes are expressed, the latter are prominent in young animals and wane with age. We speculate that, in the shark, the differential activation of the multiple isotypes can be advantageously used in receptor editing.
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Affiliation(s)
- Anna Iacoangeli
- Department of Physiology and Pharmacology, State University of New York Health Science Center at Brooklyn, Brooklyn, NY 11203; and
| | - Anita Lui
- Department of Physiology and Pharmacology, State University of New York Health Science Center at Brooklyn, Brooklyn, NY 11203; and
| | - Ushma Naik
- Department of Physiology and Pharmacology, State University of New York Health Science Center at Brooklyn, Brooklyn, NY 11203; and
| | - Yuko Ohta
- Department of Microbiology and Immunology, University of Maryland, Baltimore, MD 21201
| | - Martin Flajnik
- Department of Microbiology and Immunology, University of Maryland, Baltimore, MD 21201
| | - Ellen Hsu
- Department of Physiology and Pharmacology, State University of New York Health Science Center at Brooklyn, Brooklyn, NY 11203; and
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