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Stepanova K, Sinkorova J, Srutkova D, Sinkora M, Sinkora S, Splichal I, Splichalova A, Butler JE, Sinkora M. The order of immunoglobulin light chain κ and λ usage in primary and secondary lymphoid tissues of germ-free and conventional piglets. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2022; 131:104392. [PMID: 35271860 DOI: 10.1016/j.dci.2022.104392] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 02/21/2022] [Accepted: 03/04/2022] [Indexed: 06/14/2023]
Abstract
In pigs (Sus scrofa), the initial immunoglobulin rearrangement of the κ light chain is replaced by λ before the heavy chains rearrange, and the light chains may rearrange even later. This study investigates whether these developmental differences are reflected in the usage of IGK and IGL genes. We found large differences between peripheral B cells and those developing in the bone marrow, and between B cells in germ-free piglets and conventional pigs. During early B cell development in the bone marrow, more 3' V and 5' J gene segments for both light chains are used. However, in the peripheral naive repertoire, more 5' IGLV and 3' IGLJ genes are used. A similar shift toward the use of more 5' IGKV and 3' IGKJ genes is observed later after antigen exposure in conventional pigs. The expression profile showed that most λ+ B cells are generated earlier, while κ+ B cells develop from late precursors that already contain the λ rearrangement. The initial λ rearrangement is retained in both λ+ and κ+ B lymphocytes, and multiple λ transcripts can be found in individual cells. The overall pool of the IGLV repertoire is therefore much larger and more diversified than for IGKV. The κ repertoire is further restricted to the preferential use of only two major IGKV genes, reflecting the limitation for only two consecutive rearrangements. Tracing of silenced λ transcripts in κ+ B cells further confirmed the unconventional mechanism of differential rearrangements in pigs. Our results underline the diversity of the immune system among mammals.
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Affiliation(s)
- Katerina Stepanova
- Laboratory of Gnotobiology, Institute of Microbiology of the Czech Academy of Sciences, Novy Hradek, Czech Republic
| | - Jana Sinkorova
- Laboratory of Gnotobiology, Institute of Microbiology of the Czech Academy of Sciences, Novy Hradek, Czech Republic
| | - Dagmar Srutkova
- Laboratory of Gnotobiology, Institute of Microbiology of the Czech Academy of Sciences, Novy Hradek, Czech Republic
| | - Marek Sinkora
- Laboratory of Gnotobiology, Institute of Microbiology of the Czech Academy of Sciences, Novy Hradek, Czech Republic
| | - Simon Sinkora
- Laboratory of Gnotobiology, Institute of Microbiology of the Czech Academy of Sciences, Novy Hradek, Czech Republic
| | - Igor Splichal
- Laboratory of Gnotobiology, Institute of Microbiology of the Czech Academy of Sciences, Novy Hradek, Czech Republic
| | - Alla Splichalova
- Laboratory of Gnotobiology, Institute of Microbiology of the Czech Academy of Sciences, Novy Hradek, Czech Republic
| | - John E Butler
- Carver College of Medicine, University of Iowa, Iowa City, IA, United States
| | - Marek Sinkora
- Laboratory of Gnotobiology, Institute of Microbiology of the Czech Academy of Sciences, Novy Hradek, Czech Republic.
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Sinkora M, Stepanova K, Butler JE, Sinkora M, Sinkora S, Sinkorova J. Comparative Aspects of Immunoglobulin Gene Rearrangement Arrays in Different Species. Front Immunol 2022; 13:823145. [PMID: 35222402 PMCID: PMC8873125 DOI: 10.3389/fimmu.2022.823145] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 01/24/2022] [Indexed: 11/25/2022] Open
Abstract
Studies in humans and mice indicate the critical role of the surrogate light chain in the selection of the productive immunoglobulin repertoire during B cell development. However, subsequent studies using mutant mice have also demonstrated that alternative pathways are allowed. Our recent investigation has shown that some species, such as pig, physiologically use preferential rearrangement of authentic light chains, and become independent of surrogate light chains. Here we summarize the findings from swine and compare them with results in other species. In both groups, allelic and isotypic exclusions remain intact, so the different processes do not alter the paradigm of B-cell monospecificity. Both groups also retained some other essential processes, such as segregated and sequential rearrangement of heavy and light chain loci, preferential rearrangement of light chain kappa before lambda, and functional κ-deleting element recombination. On the other hand, the respective order of heavy and light chains rearrangement may vary, and rearrangement of the light chain kappa and lambda on different chromosomes may occur independently. Studies have also confirmed that the surrogate light chain is not required for the selection of the productive repertoire of heavy chains and can be substituted by authentic light chains. These findings are important for understanding evolutional approaches, redundancy and efficiency of B-cell generation, dependencies on other regulatory factors, and strategies for constructing therapeutic antibodies in unrelated species. The results may also be important for explaining interspecies differences in the proportional use of light chains and for the understanding of divergences in rearrangement processes. Therefore, the division into two groups may not be definitive and there may be more groups of intermediate species.
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Affiliation(s)
- Marek Sinkora
- Laboratory of Gnotobiology, Institute of Microbiology of the Czech Academy of Sciences, Novy Hradek, Czechia
| | - Katerina Stepanova
- Laboratory of Gnotobiology, Institute of Microbiology of the Czech Academy of Sciences, Novy Hradek, Czechia
| | - John E. Butler
- Department of Microbiology, University of Iowa, Iowa City, IA, United States
| | - Marek Sinkora
- Laboratory of Gnotobiology, Institute of Microbiology of the Czech Academy of Sciences, Novy Hradek, Czechia
| | - Simon Sinkora
- Laboratory of Gnotobiology, Institute of Microbiology of the Czech Academy of Sciences, Novy Hradek, Czechia
| | - Jana Sinkorova
- Laboratory of Gnotobiology, Institute of Microbiology of the Czech Academy of Sciences, Novy Hradek, Czechia
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Sinkora M, Stepanova K, Sinkorova J. Consequences of the different order of immunoglobulin gene rearrangements in swine. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2022; 126:104196. [PMID: 34242678 DOI: 10.1016/j.dci.2021.104196] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 06/14/2021] [Accepted: 06/30/2021] [Indexed: 06/13/2023]
Abstract
Swine use a reverse order of immunoglobulin chain rearrangement compared to humans and mice, and this altered and modified order should have measurable consequences. Here we perform new and defining experiments with developing and mature B cells, characterizing the B cell populations that do not exist in other species. First, we have finally confirmed that light chains κ and λ are rearranged and expressed on the surface before any heavy chain rearrangements using western-blot. And second, we have analyzed a pool of mature B cells on the single-cell level to demonstrate that many κ+ mature B cells carry λ transcripts. According to these findings, we believe that there may be more groups of mammals; one of which uses a pre-BCR-driven developmental pathway for B cell generation (like mice and humans), the second group uses a pre-BCR-independent one (like swine), and some may be even intermediate.
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Affiliation(s)
- Marek Sinkora
- Laboratory of Gnotobiology, Institute of Microbiology of the Czech Academy of Sciences, Novy Hradek, Czech Republic.
| | - Katerina Stepanova
- Laboratory of Gnotobiology, Institute of Microbiology of the Czech Academy of Sciences, Novy Hradek, Czech Republic
| | - Jana Sinkorova
- Laboratory of Gnotobiology, Institute of Microbiology of the Czech Academy of Sciences, Novy Hradek, Czech Republic
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Kasprzyk ME, Sura W, Dzikiewicz-Krawczyk A. Enhancing B-Cell Malignancies-On Repurposing Enhancer Activity towards Cancer. Cancers (Basel) 2021; 13:3270. [PMID: 34210001 PMCID: PMC8269369 DOI: 10.3390/cancers13133270] [Citation(s) in RCA: 3] [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: 05/18/2021] [Revised: 06/24/2021] [Accepted: 06/28/2021] [Indexed: 01/19/2023] Open
Abstract
B-cell lymphomas and leukemias derive from B cells at various stages of maturation and are the 6th most common cancer-related cause of death. While the role of several oncogenes and tumor suppressors in the pathogenesis of B-cell neoplasms was established, recent research indicated the involvement of non-coding, regulatory sequences. Enhancers are DNA elements controlling gene expression in a cell type- and developmental stage-specific manner. They ensure proper differentiation and maturation of B cells, resulting in production of high affinity antibodies. However, the activity of enhancers can be redirected, setting B cells on the path towards cancer. In this review we discuss different mechanisms through which enhancers are exploited in malignant B cells, from the well-studied translocations juxtaposing oncogenes to immunoglobulin loci, through enhancer dysregulation by sequence variants and mutations, to enhancer hijacking by viruses. We also highlight the potential of therapeutic targeting of enhancers as a direction for future investigation.
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Sinkora M, Stepanova K, Sinkorova J. Immunoglobulin light chain κ precedes λ rearrangement in swine but a majority of λ + B cells are generated earlier. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2020; 111:103751. [PMID: 32454063 DOI: 10.1016/j.dci.2020.103751] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/19/2020] [Accepted: 05/19/2020] [Indexed: 06/11/2023]
Abstract
Developmental pathways for B cell lymphogenesis are sufficiently known only in mice and humans. However, both of these species rearrange immunoglobulin heavy chains (IgH) before light chains (IgL) while IgL precedes IgH rearrangement in swine. We demonstrate here that this reversed order of rearrangements have some concealed consequences: (1) we confirmed that although IgLκ rearrangement is initial, most IgLλ+ B cells are generated earlier and before IgH rearrangements, while most IgLκ+ B cells later and after IgH rearrangements, (2) the second IgLκ rearrangement can occur after IgLλ rearrangement, (3) early formed B cells bear only single in-frame IgH rearrangements, (4) many IgLκ+ B cells carry IgLλ rearrangements that can be productive and occurring on both alleles in one cell, and (5) although VpreB and λ5 genes are present in swine, they are preferentially expressed in non-B cells. In summary, our findings reveal that swine use an alternative B cell developmental pathway as compared to mice and humans.
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Affiliation(s)
- Marek Sinkora
- Laboratory of Gnotobiology, Institute of Microbiology of the Czech Academy of Sciences, Novy Hradek, Czech Republic.
| | - Katerina Stepanova
- Laboratory of Gnotobiology, Institute of Microbiology of the Czech Academy of Sciences, Novy Hradek, Czech Republic
| | - Jana Sinkorova
- Laboratory of Gnotobiology, Institute of Microbiology of the Czech Academy of Sciences, Novy Hradek, Czech Republic
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Schraven AL, Stannard HJ, Ong OTW, Old JM. Immunogenetics of marsupial B-cells. Mol Immunol 2019; 117:1-11. [PMID: 31726269 DOI: 10.1016/j.molimm.2019.10.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 10/17/2019] [Accepted: 10/30/2019] [Indexed: 11/19/2022]
Abstract
Marsupials and eutherians are mammals that differ in their physiological traits, predominately their reproductive and developmental strategies; eutherians give birth to well-developed young, while marsupials are born highly altricial after a much shorter gestation. These developmental traits also result in differences in the development of the immune system of eutherian and marsupial species. In eutherians, B-cells are the key to humoral immunity as they are found in multiple lymphoid organs and have the unique ability to mediate the production of antigen-specific antibodies in the presence of extracellular pathogens. The development of B-cells in marsupials has been reported and hypothesised to be similar to that of eutherians, except that haematopoiesis occurs in the liver, postpartum, until the bone marrow fully matures. In eutherians, specific genes are linked to specific stages in B-cell development, maturation, and differentiation processes, and have been identified including immunoglobulins (heavy and light chains), cluster of differentiation markers (CD10, 19, 34 and CD79α/β), signal transduction molecules (BTK, Lyn and Syk) and transcriptional regulators (EBF1, E2A, and Pax5). This review aims to discuss the known similarities and differences between marsupial and eutherian B-cells, in regards to their genetic presence, homology, and developmental stages, as well as to highlight the areas requiring further investigation. By enhancing our understanding of the genes that are involved with B-cells in the marsupial lineage, it will, in turn, aid our understanding of the marsupial immune system and support the development of specific immunological reagents for research and wildlife conservation purposes.
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Affiliation(s)
- Andrea L Schraven
- School of Science and Health, Hawkesbury Campus, Western Sydney University, Locked bag 1797, Penrith, NSW 2751, Australia
| | - Hayley J Stannard
- Charles Sturt University, School of Animal and Veterinary Sciences, Wagga Wagga, NSW 2678, Australia
| | - Oselyne T W Ong
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Julie M Old
- School of Science and Health, Hawkesbury Campus, Western Sydney University, Locked bag 1797, Penrith, NSW 2751, Australia.
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Collins AM, Watson CT. Immunoglobulin Light Chain Gene Rearrangements, Receptor Editing and the Development of a Self-Tolerant Antibody Repertoire. Front Immunol 2018; 9:2249. [PMID: 30349529 PMCID: PMC6186787 DOI: 10.3389/fimmu.2018.02249] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 09/10/2018] [Indexed: 11/13/2022] Open
Abstract
Discussion of the antibody repertoire usually emphasizes diversity, but a conspicuous feature of the light chain repertoire is its lack of diversity. The diversity of reported allelic variants of germline light chain genes is also limited, even in well-studied species. In this review, the implications of this lack of diversity are considered. We explore germline and rearranged light chain genes in a variety of species, with a particular focus on human and mouse genes. The importance of the number, organization and orientation of the genes for the control of repertoire development is discussed, and we consider how primary rearrangements and receptor editing together shape the expressed light chain repertoire. The resulting repertoire is dominated by just a handful of IGKV and IGLV genes. It has been hypothesized that an important function of the light chain is to guard against self-reactivity, and the role of secondary rearrangements in this process could explain the genomic organization of the light chain genes. It could also explain why the light chain repertoire is so limited. Heavy and light chain genes may have co-evolved to ensure that suitable light chain partners are usually available for each heavy chain that forms early in B cell development. We suggest that the co-evolved loci of the house mouse often became separated during the inbreeding of laboratory mice, resulting in new pairings of loci that are derived from different sub-species of the house mouse. A resulting vulnerability to self-reactivity could explain at least some mouse models of autoimmune disease.
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Affiliation(s)
- Andrew M. Collins
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Corey T. Watson
- Department of Biochemistry and Molecular Genetics, University of Louisville School of Medicine, Louisville, KY, United States
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Schwartz JC, Philp RL, Bickhart DM, Smith TPL, Hammond JA. The antibody loci of the domestic goat (Capra hircus). Immunogenetics 2018; 70:317-326. [PMID: 29063126 PMCID: PMC5899754 DOI: 10.1007/s00251-017-1033-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 09/29/2017] [Indexed: 12/11/2022]
Abstract
The domestic goat (Capra hircus) is an important ruminant species both as a source of antibody-based reagents for research and biomedical applications and as an economically important animal for agriculture, particularly for developing nations that maintain most of the global goat population. Characterization of the loci encoding the goat immune repertoire would be highly beneficial for both vaccine and immune reagent development. However, in goat and other species whose reference genomes were generated using short-read sequencing technologies, the immune loci are poorly assembled as a result of their repetitive nature. Our recent construction of a long-read goat genome assembly (ARS1) has facilitated characterization of all three antibody loci with high confidence and comparative analysis to cattle. We observed broad similarity of goat and cattle antibody-encoding loci but with notable differences that likely influence formation of the functional antibody repertoire. The goat heavy-chain locus is restricted to only four functional and nearly identical IGHV genes, in contrast to the ten observed in cattle. Repertoire analysis indicates that light-chain usage is more balanced in goats, with greater representation of kappa light chains (~ 20-30%) compared to that in cattle (~ 5%). The present study represents the first characterization of the goat antibody loci and will help inform future investigations of their antibody responses to disease and vaccination.
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Affiliation(s)
| | - Rebecca L Philp
- The Pirbright Institute, Pirbright, Surrey, GU24 0NF, UK.,Boyd Orr Centre for Population and Ecosystem Health, Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Derek M Bickhart
- Cell Wall Biology and Utilization Research, USDA-ARS, Madison, WI, 53706, USA
| | | | - John A Hammond
- The Pirbright Institute, Pirbright, Surrey, GU24 0NF, UK.
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Sinkora M, Sinkorova J, Stepanova K. Ig Light Chain Precedes Heavy Chain Gene Rearrangement during Development of B Cells in Swine. THE JOURNAL OF IMMUNOLOGY 2017; 198:1543-1552. [DOI: 10.4049/jimmunol.1601035] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 12/06/2016] [Indexed: 12/16/2022]
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de Almeida CR, Hendriks RW, Stadhouders R. Dynamic Control of Long-Range Genomic Interactions at the Immunoglobulin κ Light-Chain Locus. Adv Immunol 2015; 128:183-271. [DOI: 10.1016/bs.ai.2015.07.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Das S, Hirano M, Tako R, McCallister C, Nikolaidis N. Evolutionary genomics of immunoglobulin-encoding Loci in vertebrates. Curr Genomics 2012; 13:95-102. [PMID: 23024601 PMCID: PMC3308330 DOI: 10.2174/138920212799860652] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 12/13/2011] [Accepted: 01/14/2012] [Indexed: 11/22/2022] Open
Abstract
Immunoglobulins (or antibodies) are an essential element of the jawed vertebrate adaptive immune response system. These molecules have evolved over the past 500 million years and generated highly specialized proteins that recognize an extraordinarily large number of diverse substances, collectively known as antigens. During vertebrate evolution the diversification of the immunoglobulin-encoding loci resulted in differences in the genomic organization, gene content, and ratio of functional genes and pseudogenes. The tinkering process in the immunoglobulin-encoding loci often gave rise to lineage-specific characteristics that were formed by selection to increase species adaptation and fitness. Immunoglobulin loci and their encoded antibodies have been shaped repeatedly by contrasting evolutionary forces, either to conserve the prototypic structure and mechanism of action or to generate alternative and diversified structures and modes of function. Moreover, evolution favored the development of multiple mechanisms of primary and secondary antibody diversification, which are used by different species to effectively generate an almost infinite collection of diverse antibody types. This review summarizes our current knowledge on the genomics and evolution of the immunoglobulin-encoding loci and their protein products in jawed vertebrates.
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Affiliation(s)
- Sabyasachi Das
- Department of Pathology and Laboratory Medicine, Emory Vaccine Center, School of Medicine, Emory University, USA
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13
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Schwartz JC, Lefranc MP, Murtaugh MP. Evolution of the porcine (Sus scrofa domestica) immunoglobulin kappa locus through germline gene conversion. Immunogenetics 2011; 64:303-11. [PMID: 22109540 DOI: 10.1007/s00251-011-0589-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Accepted: 11/08/2011] [Indexed: 12/14/2022]
Abstract
Immunoglobulin (IG) gene rearrangement and expression are central to disease resistance and health maintenance in animals. The IG kappa (IGK) locus in swine (Sus scrofa domestica) contributes to approximately half of all antibody molecules, in contrast to many other Cetartiodactyla, whose members provide the majority of human dietary protein and in which kappa locus utilization is limited. The porcine IGK variable locus is 27.9 kb upstream of five IG kappa J genes (IGKJ) which are separated from a single constant gene (IGKC) by 2.8 kb. Fourteen variable genes (IGKV) were identified, of which nine are functional and two are open reading frame (ORF). Of the three pseudogenes, IGKV3-1 contains a frameshift and multiple stop codons, IGKV7-2 contains multiple stop codons, and IGKV2-5 is missing exon 2. The nine functional IGKV genes are phylogenetically related to either the human IGKV1 or IGKV2 subgroups. IGKV2 subgroup genes were found to be dominantly expressed. Polymorphisms were identified on overlapping BACs derived from the same individual such that 11 genes contain amino acid differences. The most striking allelic differences are present in IGKV2 genes, which contain as many as 16 amino acid changes between alleles, the majority of which are in complementarity determining region (CDR) 1. In addition, many IGKV2 CDR1 are shared between genes but not between alleles, suggesting extensive diversification of this locus through gene conversion.
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Affiliation(s)
- John C Schwartz
- Department of Veterinary and Biomedical Sciences, University of Minnesota, 1971 Commonwealth Avenue, St. Paul, MN 55108, USA.
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14
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Zimmerman AM, Romanowski KE, Maddox BJ. Targeted annotation of immunoglobulin light chain (IgL) genes in zebrafish from BAC clones reveals kappa-like recombining/deleting elements within IgL constant regions. FISH & SHELLFISH IMMUNOLOGY 2011; 31:697-703. [PMID: 20933599 DOI: 10.1016/j.fsi.2010.09.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Revised: 09/09/2010] [Accepted: 09/20/2010] [Indexed: 05/30/2023]
Abstract
Genomic organization, composition, and microsynteny of immunoglobulin light chain (IgL) gene segments in the zebrafish were analyzed through the identification and annotation of overlapping BAC clone insert sequences and an Illumina de novo assembly. The resultant gap-free IgL annotation confirmed a number of previous conclusions about teleost IgL including: suites of (V(L)-J(L)-C(L)) clusters on multiple chromosomes; V(L) in the same or opposite transcriptional orientation as J(L) and C(L); and the apparent absence of lambda IgL in the zebrafish model. In addition, palindromic heptamers (CACAGTG or CACTGTG) within the 3' region of zebrafish C(L) were identified. In mammals, heptamers within J(κ)-C(κ) introns can recombine with downstream kappa deleting elements (Kde) to ablate C(κ) regions prior to rearrangements of V(λ)-J(λ) gene segments. The presence of palindromic heptamers within zebrafish C(L) is intriguing as their recombination with intact RSS might result in the deletion of a large portion of the C(L) thereby permanently silencing C(L) exons within the IgL locus. Given that bony fish have appreciably more C(L) spread over more chromosomes than mice and humans, it is plausible the presence of recombining sequences within C(L) may be tied to a need for heightened mechanisms to facilitate allelic exclusion or receptor editing. Collectively, with this report, gap-free annotations of the heavy and light chain Ig loci have now been completed for Danio rerio, the only teleost for which this has been accomplished, thereby strengthening the overall utility of zebrafish as a model organism for both comparative immunology and biomedical research.
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Affiliation(s)
- Anastasia M Zimmerman
- Department of Biology, College of Charleston, 66 George Street, Charleston, SC 29424, USA.
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Edholm ES, Wilson M, Bengten E. Immunoglobulin light (IgL) chains in ectothermic vertebrates. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2011; 35:906-915. [PMID: 21256861 DOI: 10.1016/j.dci.2011.01.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Revised: 01/16/2011] [Accepted: 01/16/2011] [Indexed: 05/30/2023]
Abstract
Four major ancesteral IgL isotypes have been identified κ, λ, σ and σ-cart. However, depending on the vertebrate class the genomic representation of these isotypes differs in regards to what is encoded in the germline and how these genes are organized. Also, the relative contribution of each isotype in immune responses varies. This review focuses on the IgL chains of ectothermic vertebrates, specifically the number of different isotypes, their phylogenetic relationship, genomic organizations and expression.
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Affiliation(s)
- Eva-Stina Edholm
- Department of Microbiology, University of Mississippi Medical Center, Jackson, MS 39216, United States
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Das S, Hirano M, McCallister C, Tako R, Nikolaidis N. Comparative genomics and evolution of immunoglobulin-encoding loci in tetrapods. Adv Immunol 2011; 111:143-78. [PMID: 21970954 DOI: 10.1016/b978-0-12-385991-4.00004-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The immunoglobulins (Igs or antibodies) as an integral part of the tetrapod adaptive immune response system have evolved toward producing highly diversified molecules that recognize a remarkably large number of different antigens. Antibodies and their respective encoding loci have been shaped by different and often contrasting evolutionary forces, some of which aim to conserve an established pattern or mechanism and others to generate alternative and diversified structural and functional configurations. The genomic organization, gene content, ratio between functional genes and pseudogenes, number and position of recombining genetic elements, and the different levels of divergence present at the germline of the Ig-encoding loci have been evolutionarily shaped and optimized in a lineage- and, in some cases, species-specific mode aiming to increase organismal fitness. Further, evolution favored the development of multiple mechanisms of primary and secondary antibody diversification, such as V(D)J recombination, class switch recombination, isotype exclusion, somatic hypermutation, and gene conversion. Diverse tetrapod species, based on their specific germline configurations, use these mechanisms in several different combinations to effectively generate a vast array of distinct antibody types and structures. This chapter summarizes our current knowledge on the Ig-encoding loci in tetrapods and discusses the different evolutionary mechanisms that shaped their diversification.
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Affiliation(s)
- Sabyasachi Das
- Department of Pathology and Laboratory Medicine, Emory Vaccine Center, School of Medicine, Emory University, Atlanta, Georgia, USA
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Weier HUG, Greulich-Bode KM, Wu J, Duell T. Delineating Rearrangements in Single Yeast Artificial Chromosomes by Quantitative DNA Fiber Mapping. ACTA ACUST UNITED AC 2009; 2:15-23. [PMID: 20502619 DOI: 10.2174/1875693x00902010015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Cloning of large chunks of human genomic DNA in recombinant systems such as yeast or bacterial artificial chromosomes has greatly facilitated the construction of physical maps, the positional cloning of disease genes or the preparation of patient-specific DNA probes for diagnostic purposes. For this process to work efficiently, the DNA cloning process and subsequent clone propagation need to maintain stable inserts that are neither deleted nor otherwise rearranged. Some regions of the human genome; however, appear to have a higher propensity than others to rearrange in any host system. Thus, techniques to detect and accurately characterize such rearrangements need to be developed. We developed a technique termed 'Quantitative DNA Fiber Mapping (QDFM)' that allows accurate tagging of sequence elements of interest with near kilobase accuracy and optimized it for delineation of rearrangements in recombinant DNA clones. This paper demonstrates the power of this microscopic approach by investigating YAC rearrangements. In our examples, high-resolution physical maps for regions within the immunoglobulin lambda variant gene cluster were constructed for three different YAC clones carrying deletions of 95 kb and more. Rearrangements within YACs could be demonstrated unambiguously by pairwise mapping of cosmids along YAC DNA molecules. When coverage by YAC clones was not available, distances between cosmid clones were estimated by hybridization of cosmids onto DNA fibers prepared from human genomic DNA. In addition, the QDFM technology provides essential information about clone stability facilitating closure of the maps of the human genome as well as those of model organisms.
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Affiliation(s)
- Heinz-Ulrich G Weier
- Life Sciences Division, University of California, E.O. Lawrence Berkeley National Laboratory Berkeley, CA 94720, USA
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