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Gargano C, Mauro M, Martino C, Queiroz V, Vizzini A, Luparello C, Badalamenti R, Bellistrì F, Cuttitta A, Kondo H, Longo F, Arizza V, Vazzana M. Shark immune system: A review about their immunoglobulin repertoire. FISH & SHELLFISH IMMUNOLOGY 2025; 160:110187. [PMID: 39947340 DOI: 10.1016/j.fsi.2025.110187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2024] [Revised: 02/06/2025] [Accepted: 02/09/2025] [Indexed: 03/03/2025]
Abstract
In the past few decades, the literature about the immune system of vertebrates has increased thanks to the research about new therapies and new biomolecules able to treat or eradicate many human autoimmune diseases. Researchers found that immunoglobulins (Igs) are the most versatile biomolecules able to recognize almost every existing epitope with their binding domains. Phylogenetically, the most recent vertebrates exhibit the greatest sequence diversification in their Igs to extend their ability to distinguish different antigens. Among cartilaginous fishes, the most ancient vertebrates on phylogenetic history, sharks possess four types of Igs with similar pathways to extend sequence diversity and binding domains variability. Their Ig new antigen receptor (IgNAR) represents one of the most versatile and small Ig type upon all other species. The shark species are fundamental sources of new therapeutic receptors lending a further step to treatments against several human diseases. The aim of this review is to analyze sharks Igs, focusing on IgNARs for each species.
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Affiliation(s)
- C Gargano
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Università di Palermo, Palermo, Italy
| | - M Mauro
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Università di Palermo, Palermo, Italy.
| | - C Martino
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Università di Palermo, Palermo, Italy; National Biodiversity Future Center, 90133, Palermo, Italy
| | - V Queiroz
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Sala 300, Rua do Matão, Travessa 14, n° 101, Cidade Universitária, São Paulo, 05508-090, Brazil
| | - A Vizzini
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Università di Palermo, Palermo, Italy; National Biodiversity Future Center, 90133, Palermo, Italy
| | - C Luparello
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Università di Palermo, Palermo, Italy; National Biodiversity Future Center, 90133, Palermo, Italy
| | - R Badalamenti
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Università di Palermo, Palermo, Italy
| | - F Bellistrì
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Università di Palermo, Palermo, Italy
| | - A Cuttitta
- National Research Council (CNR-ISMed), Institute for Studies on the Mediterranean, Via Filippo Parlatore, 65, 90145, Palermo, Italy
| | - H Kondo
- Laboratory of Genome Science, Department of Marine Biosciences, Tokyo University of Marine Science and Technology, Konan 4-5-7, Minato-ku, Tokyo, 108-8477, Japan
| | - F Longo
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Università di Palermo, Palermo, Italy
| | - V Arizza
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Università di Palermo, Palermo, Italy; National Biodiversity Future Center, 90133, Palermo, Italy
| | - M Vazzana
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Università di Palermo, Palermo, Italy; National Biodiversity Future Center, 90133, Palermo, Italy.
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Bachar-Wikstrom E, Dhillon B, Gill Dhillon N, Abbo L, Lindén SK, Wikstrom JD. Mass Spectrometry Analysis of Shark Skin Proteins. Int J Mol Sci 2023; 24:16954. [PMID: 38069276 PMCID: PMC10707392 DOI: 10.3390/ijms242316954] [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: 10/26/2023] [Revised: 11/21/2023] [Accepted: 11/24/2023] [Indexed: 12/18/2023] Open
Abstract
The mucus layer covering the skin of fish has several roles, including protection against pathogens and mechanical damage in which proteins play a key role. While proteins in the skin mucus layer of various common bony fish species have been explored, the proteins of shark skin mucus remain unexplored. In this pilot study, we examine the protein composition of the skin mucus in spiny dogfish sharks and chain catsharks through mass spectrometry (NanoLC-MS/MS). Overall, we identified 206 and 72 proteins in spiny dogfish (Squalus acanthias) and chain catsharks (Scyliorhinus retifer), respectively. Categorization showed that the proteins belonged to diverse biological processes and that most proteins were cellular albeit a significant minority were secreted, indicative of mucosal immune roles. The secreted proteins are reviewed in detail with emphasis on their immune potentials. Moreover, STRING protein-protein association network analysis showed that proteins of closely related shark species were more similar as compared to a more distantly related shark and a bony fish, although there were also significant overlaps. This study contributes to the growing field of molecular shark studies and provides a foundation for further research into the functional roles and potential human biomedical implications of shark skin mucus proteins.
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Affiliation(s)
- Etty Bachar-Wikstrom
- Dermatology and Venereology Division, Department of Medicine (Solna), Karolinska Institutet, 17177 Stockholm, Sweden
- Whitman Center, Marine Biological Laboratory, Woods Hole, MA 02543, USA
| | - Braham Dhillon
- Department of Plant Pathology, Fort Lauderdale Research and Education Center, IFAS, University of Florida, Davie, FL 33314, USA
| | - Navi Gill Dhillon
- Department of Biological Sciences, Nova Southeastern University, Davie, FL 33314, USA
| | - Lisa Abbo
- Whitman Center, Marine Biological Laboratory, Woods Hole, MA 02543, USA
| | - Sara K. Lindén
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, 40530 Gothenburg, Sweden
| | - Jakob D. Wikstrom
- Dermatology and Venereology Division, Department of Medicine (Solna), Karolinska Institutet, 17177 Stockholm, Sweden
- Whitman Center, Marine Biological Laboratory, Woods Hole, MA 02543, USA
- Dermato-Venereology Clinic, Karolinska University Hospital, 17176 Stockholm, Sweden
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Flajnik MF, Stanfield R, Pokidysheva EN, Boudko SP, Wilson I, Ohta Y. An Ancient MHC-Linked Gene Encodes a Nonrearranging Shark Antibody, UrIg, Convergent with IgG. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2023; 211:1042-1051. [PMID: 37540118 PMCID: PMC10530332 DOI: 10.4049/jimmunol.2300361] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 07/12/2023] [Indexed: 08/05/2023]
Abstract
Gnathostome adaptive immunity is defined by the Ag receptors, Igs and TCRs, and the MHC. Cartilaginous fish are the oldest vertebrates with these adaptive hallmarks. We and others have unearthed nonrearranging Ag receptor-like genes in several vertebrates, some of which are encoded in the MHC or in MHC paralogous regions. One of these genes, named UrIg, was detected in the class III region of the shark MHC that encodes a protein with typical V and C domains such as those found in conventional Igs and TCRs. As no transmembrane region was detected in gene models or cDNAs, the protein does not appear to act as a receptor. Unlike some other shark Ig genes, the UrIg V region shows no evidence of RAG-mediated rearrangement, and thus it is likely related to other V genes that predated the invasion of the RAG transposon. The UrIg gene is present in all elasmobranchs and evolves conservatively, unlike Igs and TCRs. Also, unlike Ig/TCR, the gene is not expressed in secondary lymphoid tissues, but mainly in the liver. Recombinant forms of the molecule form disulfide-linked homodimers, which is the form also detected in many shark tissues by Western blotting. mAbs specific for UrIg identify the protein in the extracellular matrix of several shark tissues by immunohistochemistry. We propose that UrIg is related to the V gene invaded by the RAG transposon, consistent with the speculation of emergence of Ig/TCR within the MHC or proto-MHC.
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Affiliation(s)
- Martin F Flajnik
- Department of Microbiology and Immunology, University of Maryland, Baltimore, MD
| | - Robyn Stanfield
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA
| | - Elena N Pokidysheva
- Division of Nephrology and Hypertension, Department of Medicine, Center for Matrix Biology, Vanderbilt University Medical Center, Nashville, TN
| | - Sergei P Boudko
- Division of Nephrology and Hypertension, Department of Medicine, Center for Matrix Biology, Vanderbilt University Medical Center, Nashville, TN
- Department of Biochemistry, Vanderbilt University, Nashville, TN
| | - Ian Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA
| | - Yuko Ohta
- Department of Microbiology and Immunology, University of Maryland, Baltimore, MD
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Pomarici ND, Cacciato R, Kokot J, Fernández-Quintero ML, Liedl KR. Evolution of the Immunoglobulin Isotypes-Variations of Biophysical Properties among Animal Classes. Biomolecules 2023; 13:801. [PMID: 37238671 PMCID: PMC10216798 DOI: 10.3390/biom13050801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 05/03/2023] [Accepted: 05/05/2023] [Indexed: 05/28/2023] Open
Abstract
The adaptive immune system arose around 500 million years ago in jawed fish, and, since then, it has mediated the immune defense against pathogens in all vertebrates. Antibodies play a central role in the immune reaction, recognizing and attacking external invaders. During the evolutionary process, several immunoglobulin isotypes emerged, each having a characteristic structural organization and dedicated function. In this work, we investigate the evolution of the immunoglobulin isotypes, in order to highlight the relevant features that were preserved over time and the parts that, instead, mutated. The residues that are coupled in the evolution process are often involved in intra- or interdomain interactions, meaning that they are fundamental to maintaining the immunoglobulin fold and to ensuring interactions with other domains. The explosive growth of available sequences allows us to point out the evolutionary conserved residues and compare the biophysical properties among different animal classes and isotypes. Our study offers a general overview of the evolution of immunoglobulin isotypes and advances the knowledge of their characteristic biophysical properties, as a first step in guiding protein design from evolution.
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Affiliation(s)
| | | | | | - Monica L. Fernández-Quintero
- Department of General, Inorganic and Theoretical Chemistry, Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80-82, A-6020 Innsbruck, Austria
| | - Klaus R. Liedl
- Department of General, Inorganic and Theoretical Chemistry, Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80-82, A-6020 Innsbruck, Austria
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Khalid Z, Chen Y, Yu D, Abbas M, Huan M, Naz Z, Mengist HM, Cao MJ, Jin T. IgNAR antibody: Structural features, diversity and applications. FISH & SHELLFISH IMMUNOLOGY 2022; 121:467-477. [PMID: 35077867 DOI: 10.1016/j.fsi.2022.01.027] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 01/15/2022] [Accepted: 01/16/2022] [Indexed: 06/14/2023]
Abstract
In response to the invasion of exogenous microorganisms, one of the defence strategies of the immune system is to produce antibodies. Cartilaginous fish is among those who evolved the earliest humoral immune system that utilizes immunoglobulin-type antibodies. The cartilaginous fish antibodies fall into three categories: IgW, IgM, and IgNAR. The shark Immunoglobulin Novel Antigen Receptor (IgNAR) constitutes disulfide-bonded dimers of two protein chains, similar to the heavy chain of mammalian IgGs. Shark IgNAR is the primary antibody of a shark's adaptive immune system with a serum concentration of 0.1-1.0 mg/mL. Its structure comprises of one variable (V) domain (VNAR) and five constant (C1 -C5) domains in the secretory form. VNARs are classified into several subclasses based on specific properties such as the quantity and position of additional non-canonical cysteine (Cys) residues in the VNAR. The VDJ recombination in IgNAR comprises various fragments; one variable component, three diverse sections, one joining portion, and a solitary arrangement of constant fragments framed in each IgNAR gene cluster. The re-arrangement happens just inside this gene cluster bringing about a VD1D2D3J segment. Therefore, four re-arrangement procedures create the entire VNAR space. IgNAR antibody can serve as an excellent diagnostic, therapeutic, and research tool because it has a smaller size, high specificity for antigen-binding, and perfect stability. The domain characterization, structural features, types, diversity and therapeutic applications of IgNAR molecules are highlighted in this review. It would be helpful for further research on IgNAR antibodies acting as an essential constituent of the adaptive immune system and a potential therapeutic agent.
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Affiliation(s)
- Zunera Khalid
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230001, China
| | - Yulei Chen
- College of Ocean Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Jimei University, Xiamen, Fujian, China
| | - Du Yu
- CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230027, China
| | - Misbah Abbas
- CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230027, China
| | - Ma Huan
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230001, China
| | - Zara Naz
- CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230027, China
| | - Hylemariam Mihiretie Mengist
- CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230027, China
| | - Min-Jie Cao
- College of Ocean Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Jimei University, Xiamen, Fujian, China.
| | - Tengchuan Jin
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230001, China; CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230027, China; CAS Center for Excellence in Molecular Cell Science, Chinese Academy of Science, Shanghai, 200031, China.
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6
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Matz H, Munir D, Logue J, Dooley H. The immunoglobulins of cartilaginous fishes. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2021; 115:103873. [PMID: 32979434 PMCID: PMC7708420 DOI: 10.1016/j.dci.2020.103873] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 09/12/2020] [Accepted: 09/16/2020] [Indexed: 05/12/2023]
Abstract
Cartilaginous fishes, comprising the chimeras, sharks, skates, and rays, split from the common ancestor with other jawed vertebrates approx. 450 million years ago. Being the oldest extant taxonomic group to possess an immunoglobulin (Ig)-based adaptive immune system, examination of this group has taught us much about the evolution of adaptive immunity, as well as the conserved and taxon-specific characteristics of Igs. Significant progress has been made analyzing sequences from numerous genomic and transcriptomic data sets. These findings have been supported by additional functional studies characterizing the Igs and humoral response of sharks and their relatives. This review will summarize what we have learned about the genomic organization, protein structure, and in vivo function of these Ig isotypes in cartilaginous fishes and highlight the areas where our knowledge is still lacking.
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Affiliation(s)
- Hanover Matz
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, USA; Institute of Marine and Environmental Technology, Baltimore, MD, USA
| | - Danish Munir
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
| | - James Logue
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Helen Dooley
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, USA; Institute of Marine and Environmental Technology, Baltimore, MD, USA.
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7
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Criscitiello MF, Kraev I, Lange S. Deiminated proteins in extracellular vesicles and plasma of nurse shark (Ginglymostoma cirratum) - Novel insights into shark immunity. FISH & SHELLFISH IMMUNOLOGY 2019; 92:249-255. [PMID: 31200072 DOI: 10.1016/j.fsi.2019.06.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 06/04/2019] [Accepted: 06/09/2019] [Indexed: 06/09/2023]
Abstract
Peptidylarginine deiminases (PADs) are phylogenetically conserved calcium-dependent enzymes which post-translationally convert arginine into citrulline in target proteins in an irreversible manner, causing functional and structural changes in target proteins. Protein deimination causes generation of neo-epitopes, affects gene regulation and also allows for protein moonlighting. Extracellular vesicles are found in most body fluids and participate in cellular communication via transfer of cargo proteins and genetic material. In this study, post-translationally deiminated proteins and extracellular vesicles (EVs) are described for the first time in shark plasma. We report a poly-dispersed population of shark plasma EVs, positive for phylogenetically conserved EV-specific markers and characterised by TEM. In plasma, 6 deiminated proteins, including complement and immunoglobulin, were identified, whereof 3 proteins were found to be exported in plasma-derived EVs. A PAD homologue was identified in shark plasma by Western blotting and detected an expected 70 kDa size. Deiminated histone H3, a marker of neutrophil extracellular trap formation, was also detected in nurse shark plasma. This is the first report of deiminated proteins in plasma and EVs, highlighting a hitherto unrecognized post-translational modification in key immune proteins of innate and adaptive immunity in shark.
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Affiliation(s)
- Michael F Criscitiello
- Comparative Immunogenetics Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA; Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M Health Science Center, Texas A&M University, College Station, TX, 77843, USA.
| | - Igor Kraev
- School of Life, Health and Chemical Sciences, The Open University, Walton Hall, MK7 6AA, UK.
| | - Sigrun Lange
- Tissue Architecture and Regeneration Research Group, School of Life Sciences, University of Westminster, London, W1W 6UW, UK.
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Deiss TC, Breaux B, Ott JA, Daniel RA, Chen PL, Castro CD, Ohta Y, Flajnik MF, Criscitiello MF. Ancient Use of Ig Variable Domains Contributes Significantly to the TCRδ Repertoire. THE JOURNAL OF IMMUNOLOGY 2019; 203:1265-1275. [PMID: 31341077 DOI: 10.4049/jimmunol.1900369] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 07/01/2019] [Indexed: 01/05/2023]
Abstract
The loci encoding B and T cell Ag receptors are generally distinct in commonly studied mammals, with each receptor's gene segments limited to intralocus, cis chromosomal rearrangements. The nurse shark (Ginglymostoma cirratum) represents the oldest vertebrate class, the cartilaginous fish, with adaptive immunity provided via Ig and TCR lineages, and is one species among a growing number of taxa employing Ig-TCRδ rearrangements that blend these distinct lineages. Analysis of the nurse shark Ig-TCRδ repertoire found that these rearrangements possess CDR3 characteristics highly similar to canonical TCRδ rearrangements. Furthermore, the Ig-TCRδ rearrangements are expressed with TCRγ, canonically found in the TCRδ heterodimer. We also quantified BCR and TCR transcripts in the thymus for BCR (IgHV-IgHC), chimeric (IgHV-TCRδC), and canonical (TCRδV-TCRδC) transcripts, finding equivalent expression levels in both thymus and spleen. We also characterized the nurse shark TCRαδ locus with a targeted bacterial artifical chromosome sequencing approach and found that the TCRδ locus houses a complex of V segments from multiple lineages. An IgH-like V segment, nestled within the nurse shark TCRδ translocus, grouped with IgHV-like rearrangements we found expressed with TCRδ (but not IgH) rearrangements in our phylogenetic analysis. This distinct lineage of TCRδ-associated IgH-like V segments was termed "TAILVs." Our data illustrate a dynamic TCRδ repertoire employing TCRδVs, NARTCRVs, bona fide trans-rearrangements from shark IgH clusters, and a novel lineage in the TCRδ-associated Ig-like V segments.
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Affiliation(s)
- Thaddeus C Deiss
- Comparative Immunogenetics Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843
| | - Breanna Breaux
- Comparative Immunogenetics Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843
| | - Jeannine A Ott
- Comparative Immunogenetics Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843
| | - Rebecca A Daniel
- Comparative Immunogenetics Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843
| | - Patricia L Chen
- Comparative Immunogenetics Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843
| | - Caitlin D Castro
- Department of Microbiology and Immunology, School of Medicine, University of Maryland at Baltimore, Baltimore, MD 21201; and
| | - Yuko Ohta
- Department of Microbiology and Immunology, School of Medicine, University of Maryland at Baltimore, Baltimore, MD 21201; and
| | - Martin F Flajnik
- Department of Microbiology and Immunology, School of Medicine, University of Maryland at Baltimore, Baltimore, MD 21201; and
| | - Michael F Criscitiello
- Comparative Immunogenetics Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843; .,Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M Health Science Center, Texas A&M University, College Station, TX 77843
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9
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Zhou H, Liu S, Yin X, Li Z, Yang Z, Zhou R. Molecular Origin of the Stability Difference in Four Shark IgNAR Constant Domains. Biophys J 2019; 116:1907-1917. [PMID: 31060814 DOI: 10.1016/j.bpj.2019.04.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 02/09/2019] [Accepted: 04/15/2019] [Indexed: 12/11/2022] Open
Abstract
Improving the stability of antibodies for manufacture and shelf life is one of the main focuses of antibody engineering. One stabilization strategy is to perform specific mutations in human antibodies based on highly stable antibodies in other species. To identify the key residues for mutagenesis, it is necessary to understand the roles of these residues in stabilizing the antibody. Here, we use molecular dynamics simulations to study the molecular origin of the four shark immunoglobulin new antigen receptors constant domains (C1-C4). According to the unfolding pathways and the conformational free energy surfaces in 8 M urea at 380 K, the C2 domain is the most stable, followed by C4, C1, and C3, which agrees with the experimental findings. The C1 and C3 domains follow a common unfolding pathway in which the unfolding starts from the edge strands, particularly strand g, and then gradually progresses to the inner strands. Detailed structural analysis of the C2 domain reveals a "sandwich-like" R339-E322-R341 salt-bridge cluster on strand g, which grants ultrahigh stability to the C2 domain. We further design two sets of mutations by mutating E322 to alanine or setting all atomic charges in E322 to zero to break the salt-bridge cluster in the C2 domain, which confirms the importance of the salt bridges in stability. In the C4 domain, the D80-K104 salt bridge on strand g also strengthens the stability. On the other hand, in the C1 and C3 domains, there is no salt bridge on strand g. In addition to the salt bridges, the overall hydrophobicity score of the hydrophobic core is also positively correlated with the domain stability. Our findings provide a detailed microscopic picture of the molecular origin of the four shark immunoglobulin new antigen receptors constant domains that not only explains the differences in their structural stability but also provides important insights into future antibody design.
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Affiliation(s)
- Hong Zhou
- Institute of Quantitative Biology and Medicine, State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Soochow University, Jiangsu, China
| | - Shengtang Liu
- Institute of Quantitative Biology and Medicine, State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Soochow University, Jiangsu, China
| | - Xiuhua Yin
- Institute of Quantitative Biology and Medicine, State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Soochow University, Jiangsu, China
| | - Zengpeng Li
- State Key Laboratory Breeding Base of Marine Genetic Resources, Key Laboratory of Marine Genetic Resources, Fujian Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, State Oceanic Administration, Xiamen, Fujian, China
| | - Zaixing Yang
- Institute of Quantitative Biology and Medicine, State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Soochow University, Jiangsu, China.
| | - Ruhong Zhou
- Institute of Quantitative Biology and Medicine, State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Soochow University, Jiangsu, China; IBM Thomas J. Watson Research Center, Yorktown Heights, New York; Department of Chemistry, Columbia University, New York, New York.
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10
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Potential Human Health Applications from Marine Biomedical Research with Elasmobranch Fishes. FISHES 2018. [DOI: 10.3390/fishes3040047] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Members of the subclass of fishes collectively known as elasmobranchs (Class Chondrichthyes, Subclass Elasmobranchii) include sharks, skates, rays, guitarfish, and sawfish. Having diverged from the main line of vertebrate evolution some 400 million years ago, these fishes have continued to be successful in our ever-changing oceans. Much of their success must be attributed to their uncanny ability to remain healthy. Based on decades of basic research, some of their secrets may be very close to benefitting man. In this short review, some of the molecular and cellular biological areas that show promise for potential human applications are presented. With a brief background and current status of relevant research, these topics include development of new antibiotics and novel treatments for cancer, macular degeneration, viral pathogens, and Parkinson’s disease; potentially useful genomic information from shark transcriptomes; shark antibody-derived drug delivery systems; and immune cell-derived compounds as potential cancer therapeutic agents.
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11
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Abstract
The adaptive immune system arose 500 million years ago in ectothermic (cold-blooded) vertebrates. Classically, the adaptive immune system has been defined by the presence of lymphocytes expressing recombination-activating gene (RAG)-dependent antigen receptors and the MHC. These features are found in all jawed vertebrates, including cartilaginous and bony fish, amphibians and reptiles and are most likely also found in the oldest class of jawed vertebrates, the extinct placoderms. However, with the discovery of an adaptive immune system in jawless fish based on an entirely different set of antigen receptors - the variable lymphocyte receptors - the divergence of T and B cells, and perhaps innate-like lymphocytes, goes back to the origin of all vertebrates. This Review explores how recent developments in comparative immunology have furthered our understanding of the origins and function of the adaptive immune system.
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Affiliation(s)
- Martin F Flajnik
- Department of Microbiology and Immunology, University of Maryland Baltimore, Baltimore, MD, USA.
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12
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Buonocore F, Stocchi V, Nunez-Ortiz N, Randelli E, Gerdol M, Pallavicini A, Facchiano A, Bernini C, Guerra L, Scapigliati G, Picchietti S. Immunoglobulin T from sea bass (Dicentrarchus labrax L.): molecular characterization, tissue localization and expression after nodavirus infection. BMC Mol Biol 2017; 18:8. [PMID: 28298204 PMCID: PMC5353873 DOI: 10.1186/s12867-017-0085-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 03/11/2017] [Indexed: 11/10/2022] Open
Abstract
Background Immunoglobulins (Igs) are fundamental components of the adaptive immune system of vertebrates, with the IgT/IgZ isotype specific of Teleosts. In this paper we describe the identification of an IgT heavy chain from the European sea bass (Dicentrarchus labrax L.), its molecular characterization and tissue mRNA localization by in situ hybridization. Results Sea bass IgT consists of 552 aa (Accession Number KM410929) and it contains a putative 19 amino acids long signal peptide and one potential N-glycosylation site. The C-region consists of four CH domains; each contains the cysteine and tryptophan residues required for their correct folding. Based on the recent sequencing of sea bass genome, we have identified five different genomic contigs bearing exons unequivocally pertaining to IgT (CH2, CH3 and CH4), but none corresponded to a complete IgH locus as IgT sequences were found in the highly fragmented assembled genomic regions which could not be assigned to any major scaffold. The 3D structure of sea bass IgT has been modelled using the crystal structure of a mouse Ig gamma as a template, thus showing that the amino acid sequence is suitable for the expected topology referred to an immunoglobulin-like architecture. The basal expression of sea bass IgT and IgM in different organs has been analysed: gut and gills, important mucosal organs, showed high IgT transcripts levels and this was the first indication of the possible involvement of sea bass IgT in mucosal immune responses. Moreover, sea bass IgT expression increased in gills and spleen after infection with nodavirus, highlighting the importance of IgT in sea bass immune responses. In situ hybridization confirmed the presence of IgT transcripts in the gut and it revealed a differential expression along the intestinal tract, with a major expression in the posterior intestine, suggesting the hindgut as a site for the recruitment of IgT+ cells in this species. IgT transcripts were also found in gill filaments and parallel lamellae and, for the first time, we identified scattered IgT positive cells in the liver, with a strong signal in the hepatic parenchyma. Conclusions In conclusion, we performed a full molecular characterization of IgT in sea bass that points out its possible involvement in mucosal immune responses of this species.
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Affiliation(s)
- Francesco Buonocore
- Department for Innovation in Biological, Agro-food and Forest Systems, University of Tuscia, Largo dell'Università snc, 05100, Viterbo, VT, Italy.
| | - Valentina Stocchi
- Department for Innovation in Biological, Agro-food and Forest Systems, University of Tuscia, Largo dell'Università snc, 05100, Viterbo, VT, Italy
| | - Noelia Nunez-Ortiz
- Department for Innovation in Biological, Agro-food and Forest Systems, University of Tuscia, Largo dell'Università snc, 05100, Viterbo, VT, Italy
| | - Elisa Randelli
- Department for Innovation in Biological, Agro-food and Forest Systems, University of Tuscia, Largo dell'Università snc, 05100, Viterbo, VT, Italy
| | - Marco Gerdol
- Department of Life Sciences, University of Trieste, Via Giorgieri 5, 34127, Trieste, TS, Italy
| | - Alberto Pallavicini
- Department of Life Sciences, University of Trieste, Via Giorgieri 5, 34127, Trieste, TS, Italy
| | - Angelo Facchiano
- Institute of Food Science, CNR, Via Roma, 64, 83100, Avellino, AV, Italy
| | - Chiara Bernini
- Department for Innovation in Biological, Agro-food and Forest Systems, University of Tuscia, Largo dell'Università snc, 05100, Viterbo, VT, Italy
| | - Laura Guerra
- Department for Innovation in Biological, Agro-food and Forest Systems, University of Tuscia, Largo dell'Università snc, 05100, Viterbo, VT, Italy
| | - Giuseppe Scapigliati
- Department for Innovation in Biological, Agro-food and Forest Systems, University of Tuscia, Largo dell'Università snc, 05100, Viterbo, VT, Italy
| | - Simona Picchietti
- Department for Innovation in Biological, Agro-food and Forest Systems, University of Tuscia, Largo dell'Università snc, 05100, Viterbo, VT, Italy
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Marra NJ, Richards VP, Early A, Bogdanowicz SM, Pavinski Bitar PD, Stanhope MJ, Shivji MS. Comparative transcriptomics of elasmobranchs and teleosts highlight important processes in adaptive immunity and regional endothermy. BMC Genomics 2017; 18:87. [PMID: 28132643 PMCID: PMC5278576 DOI: 10.1186/s12864-016-3411-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 12/12/2016] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Comparative genomic and/or transcriptomic analyses involving elasmobranchs remain limited, with genome level comparisons of the elasmobranch immune system to that of higher vertebrates, non-existent. This paper reports a comparative RNA-seq analysis of heart tissue from seven species, including four elasmobranchs and three teleosts, focusing on immunity, but concomitantly seeking to identify genetic similarities shared by the two lamnid sharks and the single billfish in our study, which could be linked to convergent evolution of regional endothermy. RESULTS Across seven species, we identified an average of 10,877 Swiss-Prot annotated genes from an average of 32,474 open reading frames within each species' heart transcriptome. About half of these genes were shared between all species while the remainder included functional differences between our groups of interest (elasmobranch vs. teleost and endotherms vs. ectotherms) as revealed by Gene Ontology (GO) and selection analyses. A repeatedly represented functional category, in both the uniquely expressed elasmobranch genes (total of 259) and the elasmobranch GO enrichment results, involved antibody-mediated immunity, either in the recruitment of immune cells (Fc receptors) or in antigen presentation, including such terms as "antigen processing and presentation of exogenous peptide antigen via MHC class II", and such genes as MHC class II, HLA-DPB1. Molecular adaptation analyses identified three genes in elasmobranchs with a history of positive selection, including legumain (LGMN), a gene with roles in both innate and adaptive immunity including producing antigens for presentation by MHC class II. Comparisons between the endothermic and ectothermic species revealed an enrichment of GO terms associated with cardiac muscle contraction in endotherms, with 19 genes expressed solely in endotherms, several of which have significant roles in lipid and fat metabolism. CONCLUSIONS This collective comparative evidence provides the first multi-taxa transcriptomic-based perspective on differences between elasmobranchs and teleosts, and suggests various unique features associated with the adaptive immune system of elasmobranchs, pointing in particular to the potential importance of MHC Class II. This in turn suggests that expanded comparative work involving additional tissues, as well as genome sequencing of multiple elasmobranch species would be productive in elucidating the regulatory and genome architectural hallmarks of elasmobranchs.
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Affiliation(s)
- Nicholas J Marra
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA.,Save Our Seas Shark Research Center and Guy Harvey Research Institute, Nova Southeastern University, 8000 North Ocean Drive, Dania Beach, FL, 33004, USA
| | - Vincent P Richards
- Department of Biological Sciences, Clemson University, Clemson, SC, 29634, USA
| | - Angela Early
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14853, USA
| | - Steve M Bogdanowicz
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14853, USA
| | - Paulina D Pavinski Bitar
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Michael J Stanhope
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA.
| | - Mahmood S Shivji
- Save Our Seas Shark Research Center and Guy Harvey Research Institute, Nova Southeastern University, 8000 North Ocean Drive, Dania Beach, FL, 33004, USA.
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14
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Mashoof S, Criscitiello MF. Fish Immunoglobulins. BIOLOGY 2016; 5:E45. [PMID: 27879632 PMCID: PMC5192425 DOI: 10.3390/biology5040045] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Revised: 11/03/2016] [Accepted: 11/09/2016] [Indexed: 01/19/2023]
Abstract
The B cell receptor and secreted antibody are at the nexus of humoral adaptive immunity. In this review, we summarize what is known of the immunoglobulin genes of jawed cartilaginous and bony fishes. We focus on what has been learned from genomic or cDNA sequence data, but where appropriate draw upon protein, immunization, affinity and structural studies. Work from major aquatic model organisms and less studied comparative species are both included to define what is the rule for an immunoglobulin isotype or taxonomic group and what exemplifies an exception.
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Affiliation(s)
- Sara Mashoof
- Comparative Immunogenetics Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA.
| | - Michael F Criscitiello
- Comparative Immunogenetics Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA.
- Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M University, College Station, TX 77807, USA.
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15
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Estevez O, Garet E, Olivieri D, Gambón-Deza F. Amphibians have immunoglobulins similar to ancestral IgD and IgA from Amniotes. Mol Immunol 2016; 69:52-61. [DOI: 10.1016/j.molimm.2015.11.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 11/06/2015] [Accepted: 11/11/2015] [Indexed: 01/03/2023]
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16
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Zielonka S, Empting M, Grzeschik J, Könning D, Barelle CJ, Kolmar H. Structural insights and biomedical potential of IgNAR scaffolds from sharks. MAbs 2015; 7:15-25. [PMID: 25523873 PMCID: PMC4622739 DOI: 10.4161/19420862.2015.989032] [Citation(s) in RCA: 109] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
In addition to antibodies with the classical composition of heavy and light chains, the adaptive immune repertoire of sharks also includes a heavy-chain only isotype, where antigen binding is mediated exclusively by a small and highly stable domain, referred to as vNAR. In recent years, due to their high affinity and specificity combined with their small size, high physicochemical stability and low-cost of production, vNAR fragments have evolved as promising target-binding scaffolds that can be tailor-made for applications in medicine and biotechnology. This review highlights the structural features of vNAR molecules, addresses aspects of their generation using immunization or in vitro high throughput screening methods and provides examples of therapeutic, diagnostic and other biotechnological applications.
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Key Words
- CDR, complementarity-determining region
- HV, hypervariable region
- IgNAR
- IgNAR V domain, variable domain of IgNAR
- IgNAR, immunoglobulin new antigen receptor
- VH, variable domain of the heavy chain
- VHH, variable domain of camelid heavy chain antibodies
- VL, variable domain of the light chain
- antibody technology
- biologic therapeutic
- heavy chain antibody
- mAbs, monoclonal antibodies
- scFv, single chain variable fragment
- shark
- single chain binding domain
- vNAR, variable domain of IgNAR
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Affiliation(s)
- Stefan Zielonka
- a Institute for Organic Chemistry and Biochemistry ; Technische Universität Darmstadt ; Darmstadt , Germany
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17
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Alternative adaptive immunity strategies: coelacanth, cod and shark immunity. Mol Immunol 2015; 69:157-69. [PMID: 26423359 DOI: 10.1016/j.molimm.2015.09.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 08/31/2015] [Accepted: 09/01/2015] [Indexed: 01/30/2023]
Abstract
The advent of high throughput sequencing has permitted to investigate the genome and the transcriptome of novel non-model species with unprecedented depth. This technological advance provided a better understanding of the evolution of adaptive immune genes in gnathostomes, revealing several unexpected features in different fish species which are of particular interest. In the present paper, we review the current understanding of the adaptive immune system of the coelacanth, the elephant shark and the Atlantic cod. The study of coelacanth, the only living extant of the long thought to be extinct Sarcopterygian lineage, is fundamental to bring new insights on the evolution of the immune system in higher vertebrates. Surprisingly, coelacanths are the only known jawed vertebrates to lack IgM, whereas two IgD/W loci are present. Cartilaginous fish are of great interest due to their basal position in the vertebrate tree of life; the genome of the elephant shark revealed the lack of several important immune genes related to T cell functions, which suggest the existence of a primordial set of TH1-like cells. Finally, the Atlantic cod lacks a functional major histocompatibility II complex, but balances this evolutionary loss with the expansion of specific gene families, including MHC I, Toll-like receptors and antimicrobial peptides. Overall, these data point out that several fish species present an unconventional adaptive immune system, but the loss of important immune genes is balanced by adaptive evolutionary strategies which still guarantee the establishment of an efficient immune response against the pathogens they have to fight during their life.
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18
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Abstract
As in mammals, cartilaginous and teleost fishes possess adaptive immune systems based on antigen recognition by immunoglobulins (Ig), T cell receptors (TCR), and major histocompatibility complex molecules (MHC) I and MHC II molecules. Also it is well established that fish B cells and mammalian B cells share many similarities, including Ig gene rearrangements, and production of membrane Ig and secreted Ig forms. This chapter provides an overview of the IgH and IgL chains in cartilaginous and bony fish, including their gene organizations, expression, diversity of their isotypes, and development of the primary repertoire. Furthermore, when possible, we have included summaries of key studies on immune mechanisms such as allelic exclusion, somatic hypermutation, affinity maturation, class switching, and mucosal immune responses.
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Affiliation(s)
- Eva Bengtén
- Department of Microbiology and Immunology, University of Mississippi Medical Center, Jackson, MS, 39216-4505, USA.
| | - Melanie Wilson
- Department of Microbiology and Immunology, University of Mississippi Medical Center, Jackson, MS, 39216-4505, USA.
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19
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The structural analysis of shark IgNAR antibodies reveals evolutionary principles of immunoglobulins. Proc Natl Acad Sci U S A 2014; 111:8155-60. [PMID: 24830426 DOI: 10.1073/pnas.1321502111] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Sharks and other cartilaginous fish are the phylogenetically oldest living organisms that rely on antibodies as part of their adaptive immune system. They produce the immunoglobulin new antigen receptor (IgNAR), a homodimeric heavy chain-only antibody, as a major part of their humoral adaptive immune response. Here, we report the atomic resolution structure of the IgNAR constant domains and a structural model of this heavy chain-only antibody. We find that despite low sequence conservation, the basic Ig fold of modern antibodies is already present in the evolutionary ancient shark IgNAR domains, highlighting key structural determinants of the ubiquitous Ig fold. In contrast, structural differences between human and shark antibody domains explain the high stability of several IgNAR domains and allowed us to engineer human antibodies for increased stability and secretion efficiency. We identified two constant domains, C1 and C3, that act as dimerization modules within IgNAR. Together with the individual domain structures and small-angle X-ray scattering, this allowed us to develop a structural model of the complete IgNAR molecule. Its constant region exhibits an elongated shape with flexibility and a characteristic kink in the middle. Despite the lack of a canonical hinge region, the variable domains are spaced appropriately wide for binding to multiple antigens. Thus, the shark IgNAR domains already display the well-known Ig fold, but apart from that, this heavy chain-only antibody employs unique ways for dimerization and positioning of functional modules.
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20
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Castro CD, Ohta Y, Dooley H, Flajnik MF. Noncoordinate expression of J-chain and Blimp-1 define nurse shark plasma cell populations during ontogeny. Eur J Immunol 2013; 43:3061-75. [PMID: 23897025 DOI: 10.1002/eji.201343416] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Revised: 06/03/2013] [Accepted: 07/24/2013] [Indexed: 12/16/2022]
Abstract
B-lymphocyte-induced maturation protein 1 (Blimp-1) is the master regulator of plasma cell development, controlling genes such as those encoding J-chain and secretory Ig heavy chain. However, some mammalian plasma cells do not express J-chain, and mammalian B1 cells secrete "natural" IgM antibodies without upregulating Blimp-1. While these results have been controversial in mammalian systems, here we describe subsets of normally occurring Blimp-1(-) antibody-secreting cells in nurse sharks, found in lymphoid tissues at all ontogenic stages. Sharks naturally produce large amounts of both pentameric (classically "19S") and monomeric (classically "7S") IgM, the latter an indicator of adaptive immunity. Consistent with the mammalian paradigm, shark Blimp-1 is expressed in splenic 7S IgM-secreting cells, though rarely detected in the J-chain(+) cells producing 19S IgM. Although IgM transcript levels are lower in J-chain(+) cells, these cells nevertheless secrete 19S IgM in the absence of Blimp-1, as demonstrated by ELISPOT and metabolic labeling. Additionally, cells in the shark BM equivalent (epigonal) are Blimp-1(-). Our data suggest that, in sharks, 19S-secreting cells and other secreting memory B cells in the epigonal are maintained for long periods without Blimp-1, but like in mammals, Blimp-1 is required for terminating the B-cell program following an adaptive immune response in the spleen.
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Affiliation(s)
- Caitlin D Castro
- Department of Microbiology and Immunology, University of Maryland, Baltimore, MD, USA
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21
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Zhang C, Du Pasquier L, Hsu E. Shark IgW C region diversification through RNA processing and isotype switching. THE JOURNAL OF IMMUNOLOGY 2013; 191:3410-8. [PMID: 23935192 DOI: 10.4049/jimmunol.1301257] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Sharks and skates represent the earliest vertebrates with an adaptive immune system based on lymphocyte Ag receptors generated by V(D)J recombination. Shark B cells express two classical Igs, IgM and IgW, encoded by an early, alternative gene organization consisting of numerous autonomous miniloci, where the individual gene cluster carries a few rearranging gene segments and one C region, μ or ω. We have characterized eight distinct Ig miniloci encoding the nurse shark ω H chain. Each cluster consists of VH, D, and JH segments and six to eight C domain exons. Two interspersed secretory exons, in addition to the 3'-most C exon with tailpiece, provide the gene cluster with the ability to generate at least six secreted isoforms that differ as to polypeptide length and C domain combination. All clusters appear to be functional, as judged by the capability for rearrangement and absence of defects in the deduced amino acid sequence. We previously showed that IgW VDJ can perform isotype switching to μ C regions; in this study, we found that switching also occurs between ω clusters. Thus, C region diversification for any IgW VDJ can take place at the DNA level by switching to other ω or μ C regions, as well as by RNA processing to generate different C isoforms. The wide array of pathogens recognized by Abs requires different disposal pathways, and our findings demonstrate complex and unique pathways for C effector function diversity that evolved independently in cartilaginous fishes.
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Affiliation(s)
- Cecilia Zhang
- Department of Physiology and Pharmacology, State University of New York Health Science Center at Brooklyn, Brooklyn, NY 11203, USA
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22
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Extensive diversification of IgH subclass-encoding genes and IgM subclass switching in crocodilians. Nat Commun 2013; 4:1337. [PMID: 23299887 DOI: 10.1038/ncomms2317] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Accepted: 11/22/2012] [Indexed: 01/01/2023] Open
Abstract
Crocodilians are a group of reptiles that are closely related to birds and are thought to possess a strong immune system. Here we report that the IgH locus in the Siamese crocodile and the Chinese alligator contains multiple μ genes, in contrast to other tetrapods. Both the μ2 and μ3 genes are expressed through class-switch recombination involving the switch region and germline transcription. Both IgM1 and IgM2 are present in the serum as polymers, which implies that IgM class switching may have significant roles in humoural immunity. The crocodilian α genes are the first IgA-encoding genes identified in reptiles, and these genes show an inverted transcriptional orientation similar to that of birds. The identification of both α and δ genes in crocodilians suggests that the IgH loci of modern living mammals, reptiles and birds share a common ancestral organization.
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23
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Xu B, Wang J, Zhang M, Wang P, Wei Z, Sun Y, Tao Q, Ren L, Hu X, Guo Y, Fei J, Zhang L, Li N, Zhao Y. Expressional analysis of immunoglobulin D in cattle (Bos taurus), a large domesticated ungulate. PLoS One 2012; 7:e44719. [PMID: 23028592 PMCID: PMC3441446 DOI: 10.1371/journal.pone.0044719] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Accepted: 08/09/2012] [Indexed: 12/29/2022] Open
Abstract
For decades, it has remained unknown whether artiodactyls, such as cattle, pigs, and sheep, express immunoglobulin D (IgD), although the δ gene was identified in these species nearly 10 years ago. By developing a mouse anti-bovine IgD heavy chain monoclonal antibody (13C2), we show that secreted bovine IgD was present mainly as a monomer in serum and was heavily glycosylated by N-linked saccharides. Nonetheless, IgD was detectable in some but not all of the Holstein cattle examined. Membrane-bound IgD was detected in the spleen by western blotting. Flow cytometric analysis demonstrated that IgD-positive B cells constituted a much lower percentage of B cells in the bovine spleen (∼6.8% of total B cells), jejunal Peyer's patches (∼0.8%), and peripheral blood leukocytes (∼1.2%) than in humans and mice. Furthermore, IgD-positive B cells were almost undetectable in bovine bone marrow and ileal Peyer's patches. We also demonstrated that the bovine δ gene can be expressed via class switch recombination. Accordingly, bovine δ germline transcription, which involves an Iδ exon and is highly homologous to Iμ, was confirmed. However, we could not identify an Iδ promoter, despite bovine Eμ demonstrating both enhancer and promoter activity. This study has answered a long-standing question in cattle B cell biology and significantly contributes to our understanding of B cell development in this species.
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Affiliation(s)
- Beilei Xu
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing, P. R. China
| | - Jing Wang
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing, P. R. China
| | - Min Zhang
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing, P. R. China
| | - Ping Wang
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing, P. R. China
| | - Zhiguo Wei
- College of Animal Science and Technology, Henan University of Science and Technology, Henan, P. R. China
| | - Yi Sun
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing, P. R. China
| | - Qiqing Tao
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing, P. R. China
| | - Liming Ren
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing, P. R. China
| | - Xiaoxiang Hu
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing, P. R. China
| | - Ying Guo
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing, P. R. China
| | - Jing Fei
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing, P. R. China
| | - Lei Zhang
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing, P. R. China
| | - Ning Li
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing, P. R. China
| | - Yaofeng Zhao
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing, P. R. China
- Key Laboratory of Animal Reproduction and Germplasm Enhancement in Universities of Shandong, College of Animal Science and Technology, Qingdao Agricultural University, Qingdao, P. R. China
- * E-mail:
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Immunoglobulin from Antarctic fish species of Rajidae family. Mar Genomics 2012; 5:35-41. [DOI: 10.1016/j.margen.2011.09.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Revised: 09/06/2011] [Accepted: 09/07/2011] [Indexed: 11/17/2022]
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25
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Edholm ES, Bengten E, Wilson M. Insights into the function of IgD. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2011; 35:1309-16. [PMID: 21414345 DOI: 10.1016/j.dci.2011.03.002] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Revised: 02/02/2011] [Accepted: 03/06/2011] [Indexed: 05/13/2023]
Abstract
IgD, previously thought to be a recent addition to the immunoglobulin classes, has long been considered an enigmatic molecule. For example, it was debated if IgD had a specific function other than as an antigen receptor co-expressed with IgM on naive B cells and if it had an important role in mammalian immunity. However, during the past decade extensive sequencing of vertebrate genomes has shown that IgD homologs are present in all vertebrate taxa, except for birds. Moreover, recent functional studies indicate that IgD likely performs a unique role in vertebrate immune responses. The goal of this review is to summarize the IgD gene organization and structural data, which demonstrate that IgD has an ancient origin, and discuss the findings in catfish and humans that provide insight into the possible function of this elusive immunoglobulin isotype.
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Affiliation(s)
- Eva-Stina Edholm
- University of Mississippi Medical Center, Jackson, MS 39216, USA
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26
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Gambón-Deza F, Sánchez-Espinel C, Magadán-Mompó S. Presence of an unique IgT on the IGH locus in three-spined stickleback fish (Gasterosteus aculeatus) and the very recent generation of a repertoire of VH genes. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2010; 34:114-22. [PMID: 19733587 DOI: 10.1016/j.dci.2009.08.011] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2009] [Revised: 08/27/2009] [Accepted: 08/28/2009] [Indexed: 05/13/2023]
Abstract
This study describes the IGH locus in Gasterosteus aculeatus, with 10 genes encoding three immunoglobulin classes: IgT, IgM and IgD. These genes are organized into a structure with three repeats of IGHT-IGHM-IGHD separated by segments including the VH segments. There was also a fourth IGHT gene. IGHT encodes an antibody with three immunoglobulin domains. Comparative studies indicate it is related to IgT and IgZ and other antibodies located upstream of the IGHM in teleost fish. The IGHM and IGHD are similar to the ones described in teleost. The IGHM has four immunoglobulin domains while the IGHD seven and none is duplicated. The IGH locus of G. aculeatus has 49 VH segments located in four regions. They belonged to four families, whose members show a greater than 92% amino acid identity, indicating that VH families diversified recently. Phylogenetic reconstruction suggests they were originated from four VH segments that must have duplicated with the constant region genes, after that the four VH segments gave rise to the remaining segments. This suggests the presence of an active biological process that generates diversity in VH regions.
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Affiliation(s)
- Francisco Gambón-Deza
- Unidad de Inmunología, Hospital do Meixoeiro, Carretera de Madrid s/n, Pontevedra, Spain.
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Flajnik MF, Kasahara M. Origin and evolution of the adaptive immune system: genetic events and selective pressures. Nat Rev Genet 2009; 11:47-59. [PMID: 19997068 DOI: 10.1038/nrg2703] [Citation(s) in RCA: 610] [Impact Index Per Article: 38.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The adaptive immune system (AIS) in mammals, which is centred on lymphocytes bearing antigen receptors that are generated by somatic recombination, arose approximately 500 million years ago in jawed fish. This intricate defence system consists of many molecules, mechanisms and tissues that are not present in jawless vertebrates. Two macroevolutionary events are believed to have contributed to the genesis of the AIS: the emergence of the recombination-activating gene (RAG) transposon, and two rounds of whole-genome duplication. It has recently been discovered that a non-RAG-based AIS with similarities to the jawed vertebrate AIS - including two lymphoid cell lineages - arose in jawless fish by convergent evolution. We offer insights into the latest advances in this field and speculate on the selective pressures that led to the emergence and maintenance of the AIS.
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Affiliation(s)
- Martin F Flajnik
- Department of Microbiology and Immunology, University of Maryland at Baltimore, Baltimore, Maryland 21201, USA.
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Zhao Y, Cui H, Whittington CM, Wei Z, Zhang X, Zhang Z, Yu L, Ren L, Hu X, Zhang Y, Hellman L, Belov K, Li N, Hammarström L. Ornithorhynchus anatinus (platypus) links the evolution of immunoglobulin genes in eutherian mammals and nonmammalian tetrapods. THE JOURNAL OF IMMUNOLOGY 2009; 183:3285-93. [PMID: 19675164 DOI: 10.4049/jimmunol.0900469] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The evolutionary origins of mammalian immunoglobulin H chain isotypes (IgM, IgD, IgG, IgE, and IgA) are still incompletely understood as these isotypes differ considerably in structure and number from their counterparts in nonmammalian tetrapods. We report in this study that the platypus (Ornithorhynchus anatinus) Ig H chain constant region gene locus contains eight Ig encoding genes, which are arranged in an mu-delta-omicron-gamma2-gamma1-alpha1-epsilon-alpha2 order, spanning a total of approximately 200 kb DNA, encoding six distinct isotypes. The omicron (omicron for Ornithorhynchus) gene encodes a novel Ig H chain isotype that consists of four constant region domains and a hinge, and is structurally different from any of the five known mammalian Ig classes. This gene is phylogenetically related to upsilon (epsilon) and gamma, and thus appears to be a structural intermediate between these two genes. The platypus delta gene encodes ten heavy chain constant region domains, lacks a hinge region and is similar to IgD in amphibians and fish, but strikingly different from that in eutherian mammals. The platypus Ig H chain isotype repertoire thus shows a unique combination of genes that share similarity both to those of nonmammalian tetrapods and eutherian animals and demonstrates how phylogenetically informative species can be used to reconstruct the evolutionary history of functionally important genes.
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Affiliation(s)
- Yaofeng Zhao
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, People's Republic of China.
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Abstract
Xenopus laevis is the model of choice for evolutionary, comparative, and developmental studies of immunity, and invaluable research tools including MHC-defined clones, inbred strains, cell lines, and monoclonal antibodies are available for these studies. Recent efforts to use Silurana (Xenopus) tropicalis for genetic analyses have led to the sequencing of the whole genome. Ongoing genome mapping and mutagenesis studies will provide a new dimension to the study of immunity. Here we review what is known about the immune system of X. laevis integrated with available genomic information from S. tropicalis. This review provides compelling evidence for the high degree of similarity and evolutionary conservation between Xenopus and mammalian immune systems. We propose to build a powerful and innovative comparative biomedical model based on modern genetic technologies that takes take advantage of X. laevis and S. tropicalis, as well as the whole Xenopus genus. Developmental Dynamics 238:1249-1270, 2009. (c) 2009 Wiley-Liss, Inc.
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Affiliation(s)
- Jacques Robert
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, New York, USA.
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Kubrycht J, Sigler K, Růzicka M, Soucek P, Borecký J, Jezek P. Ancient Phylogenetic Beginnings of Immunoglobulin Hypermutation. J Mol Evol 2006; 63:691-706. [PMID: 17031458 DOI: 10.1007/s00239-006-0051-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2005] [Accepted: 04/20/2006] [Indexed: 12/15/2022]
Abstract
Many structures and molecules closely related to those involved in the specific process of immunoglobulin (Ig) hypermutation existed before the appearance of primordial Ig genes. Consequently, these structures can be found even in animals and organisms distinct from vertebrates; likewise, homologues of hypermutation enzymes are present in a broad range of species, from bacteria to mammals. Our analysis, based predominantly on primary structure, demonstrates the existence of molecules similar to Ig domains, variable Ig domains (IGv), and antigen receptors (AR) in unicellular organisms, nonvertebrate metazoans, and nonvertebrate Coelomata, respectively. In addition, we deal here with some important structural properties of CDR1-like segments of the selected sponge adhesion molecule GCSAMS exhibiting chimerical Ig domain similarities, and demonstrate the occurrence of conserved regions corresponding to Ohno's modern intact primordial building block in the C-terminal part of IGv-related segments of nonvertebrate origin. The results of our analysis are also discussed with respect to the possible phylogeny of molecules preceding the hypothetical common antigen receptor ancestor.
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Affiliation(s)
- Jaroslav Kubrycht
- Center of Occupational Medicine, National Institute of Public Health, 100 42 Prague, Czech Republic.
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IgD, like IgM, is a primordial immunoglobulin class perpetuated in most jawed vertebrates. Proc Natl Acad Sci U S A 2006; 103:10723-8. [PMID: 16818885 DOI: 10.1073/pnas.0601407103] [Citation(s) in RCA: 155] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
IgD has remained a mysterious Ig class and a bane to immunology students since its discovery >40 years ago. Its spotty occurrence in mammals and birds and the discovery of an isotype with similarities to IgD in bony fish are perplexing. We have identified IgD heavy (H) chain (delta) from the amphibian Xenopus tropicalis during examination of the IgH locus. The Xenopus delta gene is in the same position, immediately 3' of the IgM gene, as in mammals, and it is expressed only in the spleen at low levels, primarily as a transmembrane receptor by surface IgM(+) cells. Our data suggest that frog IgD is expressed on mature B cells, like in mouse/human. Unexpectedly, Xenopus IgD is orthologous to IgW, an Ig isotype found only in cartilaginous fish and lungfish, demonstrating that IgD/W, like IgM, was present in the ancestor of all living jawed vertebrates. In striking contrast to IgM, IgD/W is evolutionarily labile, showing many duplications/deletions of domains, the presence of multiple splice forms, existence as predominantly a secretory or transmembrane form, or loss of the entire gene in a species-specific manner. Our study suggests that IgD/W has played varied roles in different vertebrate taxa since the inception of the adaptive immune system, and it may have been preserved as a flexible locus over evolutionary time to complement steadfast IgM.
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Zhu J, Yan K, Lu L, Peng C, Zhou C, Chen S, Xie X, Dong M, Xu A. Molecular cloning and characterization of CD9 cDNA from cartilaginous fish, red stingray, Dasyatis akajei. Mol Immunol 2006; 43:1534-40. [PMID: 16359730 DOI: 10.1016/j.molimm.2005.10.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2005] [Revised: 10/09/2005] [Accepted: 10/14/2005] [Indexed: 11/23/2022]
Abstract
CD9 is a glycoprotein of the transmembrane 4 superfamily (TM4SF) and is involved in various cellular processes. In this study, we describe the isolation of the full-length cDNA encoding for CD9 molecule (daCD9) of red stingray, Dasyatis akajei. This 1252 bp cDNA was isolated from leukocyte cDNA library and contains 681 bp open reading frame encoding 226 amino acid residues. Amino acid sequences analysis and structure prediction display approximately 50% identity to higher vertebrates with the presence of conserved structures, including the four transmembrane domains and certain characteristic residues. Southern blot analysis shows that daCD9 exists as a single copy gene. Northern blot analysis reveals that daCD9 is highly expressed in gill and spleen although its expression can be found in other tissues suggesting daCD9 might play an important role in immune defense in this fish.
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Affiliation(s)
- Junjie Zhu
- Department of Biochemistry, College of Life Sciences, Sun Yat-sen (Zhongshan) University, 135 Xingangxi Road, Guangzhou 510275, People's Republic of China
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Abstract
The mechanism of recombination-activating gene (RAG)-mediated rearrangement exists in all jawed vertebrates, but the organization and structure of immunoglobulin (Ig) genes, as they differ in fish and among fish species, reveal their capability for rapid evolution. In systems where there can exist 100 Ig loci, exon restructuring and sequence changes of the constant regions led to divergence of effector functions. Recombination among these loci created hybrid genes, the strangest of which encode variable (V) regions that function as part of secreted molecules and, as the result of an ancient translocation, are also grafted onto the T-cell receptor. Genomic changes in V-gene structure, created by RAG recombinase acting on germline recombination signal sequences, led variously to the generation of fixed receptor specificities, pseudogene templates for gene conversion, and ultimately to Ig sequences that evolved away from Ig function. The presence of so many Ig loci in fishes raises interesting questions not only as to how their regulation is achieved but also how successive whole-locus duplications are accommodated by a system whose function in other vertebrates is based on clonal antigen receptor expression.
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Affiliation(s)
- Ellen Hsu
- Department of Physiology and Pharmacology, State University of New York Health Science Center at Brooklyn, Brooklyn, NY 11203, USA.
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Marchalonis JJ, Adelman MK, Schluter SF, Ramsland PA. The antibody repertoire in evolution: chance, selection, and continuity. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2006; 30:223-47. [PMID: 16083959 DOI: 10.1016/j.dci.2005.06.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
All jawed vertebrates contain the genetic elements essential for the function of the adaptive/combinatorial immune response, have diverse sets of natural antibodies resulting from segmental gene recombination, express comparable functional repertoires and can produce specific antibodies following appropriate immunization. Profound variability occurs in the third hypervariable (CDR3) segments of light and heavy chains even within antibodies of the same ostensible specificity. Germline VH and VL elements, as well as the joining (J) segments are highly conserved among the distinct vertebrate species. Conservation is particularly noted among the VH3-like sequences of all jawed vertebrates in the FR2 and FR3 segments, as well as in the FGXGT(R or K)L J-segment characteristic of light chains and TCRs and the WGXGT(uncharged)VT JH segments. Human VH3-53 and Vlambda6 family orthologs may be present over the entire range of vertebrates. Models of the three-dimensional structures of shark VH/VL combining sites indicate similarity in framework structure and comparable CDR usage to those of man. Although carcharhine shark VH regions show greater than 50% identity to the human VH germline prototype, searches of lower deuterostome and invertebrate databases fail to detect molecules with significant relatedness. Overall, antibodies of jawed vertebrates show tremendous individual diversity, but are constructed incorporating design features that arose with the evolutionary emergence of the jawed vertebrates and have been conserved through at least 450 million years of evolutionary time.
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Affiliation(s)
- John J Marchalonis
- Department of Microbiology and Immunology, College of Medicine, University of Arizona, 1501 N. Campbell Ave., Tucson, AZ 85724-5049, USA.
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Dooley H, Flajnik MF. Antibody repertoire development in cartilaginous fish. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2006; 30:43-56. [PMID: 16146649 DOI: 10.1016/j.dci.2005.06.022] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
There are 3 H chain and 3 L chain isotypes in the cartilaginous fish, all encoded by genes in the so-called cluster (VDDJ, VJ) organization. The H chain isotypes IgM and IgNAR, are readily detected at the protein level in most species. The third is readily identified at the protein level in skates (IgR) but only via immunoprecipitation or at the transcript level in sharks (IgW). High levels of diversity in CDR3 and up to 200 germline genes have been detected for IgM depending upon the species examined. IgNAR displays very high levels of CDR3 diversity but almost none in the germline. At least IgNAR and L chain genes have been shown to hypermutate to very high levels, apparently in response to antigen. The mutation footprints are similar to those in mammals except that the shark genes uniquely mutate nucleotide residues in tandem. A conspicuous feature of cartilaginous fish Ig genes is the presence of germline-joined genes, which are a result of RAG activity in germ cells. Such genes are expressed early in ontogeny and then extinguished or expressed at lower levels. 19S IgM and IgW expression precede that of 7S IgM and IgNAR during ontogeny. The 'switch' from 19S to 7S IgM, the regulation of expression of the Ig clusters, and the microenvironments for mutation/selection of cartilaginous fish B cells are all areas of ongoing research.
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Affiliation(s)
- H Dooley
- Department of Microbiology and Immunology, University of Maryland School of Medicine, 655 West Baltimore Street, Baltimore, MD 21201, USA
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Data on the isolation of immunoglobulin from the serum of the green frog: Rana esculenta. ACTA VETERINARIA 2006. [DOI: 10.2298/avb0603111s] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Hansen JD, Landis ED, Phillips RB. Discovery of a unique Ig heavy-chain isotype (IgT) in rainbow trout: Implications for a distinctive B cell developmental pathway in teleost fish. Proc Natl Acad Sci U S A 2005; 102:6919-24. [PMID: 15863615 PMCID: PMC1100771 DOI: 10.1073/pnas.0500027102] [Citation(s) in RCA: 343] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
During the analysis of Ig superfamily members within the available rainbow trout (Oncorhynchus mykiss) EST gene index, we identified a unique Ig heavy-chain (IgH) isotype. cDNAs encoding this isotype are composed of a typical IgH leader sequence and a VDJ rearranged segment followed by four Ig superfamily C-1 domains represented as either membrane-bound or secretory versions. Because teleost fish were previously thought to encode and express only two IgH isotypes (IgM and IgD) for their humoral immune repertoire, we isolated all three cDNA isotypes from a single homozygous trout (OSU-142) to confirm that all three are indeed independent isotypes. Bioinformatic and phylogenetic analysis indicates that this previously undescribed divergent isotype is restricted to bony fish, thus we have named this isotype "IgT" (tau) for teleost fish. Genomic sequence analysis of an OSU-142 bacterial artificial chromosome (BAC) clone positive for all three IgH isotypes revealed that IgT utilizes the standard rainbow trout V(H) families, but surprisingly, the IgT isotype possesses its own exclusive set of D(H) and J(H) elements for the generation of diversity. The IgT D and J segments and tau constant (C) region genes are located upstream of the D and J elements for IgM, representing a genomic IgH architecture that has not been observed in any other vertebrate class. All three isotypes are primarily expressed in the spleen and pronephros (bone marrow equivalent), and ontogenically, expression of IgT is present 4 d before hatching in developing embryos.
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Affiliation(s)
- John D Hansen
- Western Fisheries Research Center, Biological Resources Division and Department of Pathobiology, U.S. Geological Survey and University of Washington, Seattle, WA 98115, USA.
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Abstract
This review discusses evolution of the process of Ig heavy chain class switching, relating it to the first appearance of somatic hypermutation (SHM) of variable region genes. First, we discuss recent findings on the mechanism of class switch recombination (CSR) in mice and humans, and then review the mechanisms of expression of Ig heavy chain isotypes from fishes to mammals. Importantly, activation-induced cytidine deaminase (AID), which is essential for CSR and somatic hypermutation, is found in fishes. Although at least some fishes are likely to undergo SHM, CSR is highly unlikely to occur in this group. We discuss the first appearance of CSR in amphibians and how it differs in birds and mammals.
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Affiliation(s)
- Janet Stavnezer
- Department of Molecular Genetics and Microbiology, Program in Immunology and Virology, University of Massachusetts Medical School, 55 Lake Ave N, Worcester, MA 01655-0122, USA.
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Rumfelt LL, Diaz M, Lohr RL, Mochon E, Flajnik MF. Unprecedented Multiplicity of Ig Transmembrane and Secretory mRNA Forms in the Cartilaginous Fish. THE JOURNAL OF IMMUNOLOGY 2004; 173:1129-39. [PMID: 15240702 DOI: 10.4049/jimmunol.173.2.1129] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In most jawed vertebrates including cartilaginous fish, membrane-bound IgM is expressed as a five Ig superfamily (Igsf)-domain H chain attached to a transmembrane (Tm) region. Heretofore, bony fish IgM was the one exception with IgM mRNA spliced to produce a four-domain Tm H chain. We now demonstrate that the Tm and secretory (Sec) mRNAs of the novel cartilaginous fish Ig isotypes, IgW and IgNAR, are present in multiple forms, most likely generated by alternative splicing. In the nurse shark, Ginglymostoma cirratum, and horn shark, Heterodontus francisci, alternative splicing of Tm exons to the second or the fourth constant (C(H)) exons produces two distinct IgW Tm cDNAs. Although the seven-domain IgW Sec cDNA form contains a canonical secretory tail shared with IgM, IgNAR, and IgA, we report a three-domain cDNA form of shark IgW (IgW(short)) having an unusual Sec tail, which is orthologous to skate IgX(short) cDNA. The IgW and IgW(short) Sec transcripts are restricted in their tissue distribution and expression levels vary among individual sharks, with all forms expressed early in ontogeny. IgNAR mRNA is alternatively spliced to produce a truncated four-domain Tm cDNA and a second Tm cDNA is expressed identical in Igsf domains as the Sec form. PBL is enriched in the Tm cDNA of these Igs. These molecular data suggest that cartilaginous fish have augmented their humoral immune repertoire by diversifying the sizes of their Ig isotypes. Furthermore, these Tm cDNAs are prototypical and the truncated variants may translate as more stable protein at the cell surface.
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Affiliation(s)
- Lynn L Rumfelt
- Department of Microbiology and Immunology, University of Miami School of Medicine, Miami, FL 33101, USA.
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Rumfelt LL, Lohr RL, Dooley H, Flajnik MF. Diversity and repertoire of IgW and IgM VH families in the newborn nurse shark. BMC Immunol 2004; 5:8. [PMID: 15132758 PMCID: PMC420240 DOI: 10.1186/1471-2172-5-8] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2004] [Accepted: 05/06/2004] [Indexed: 11/10/2022] Open
Abstract
Background Adult cartilaginous fish express three immunoglobulin (Ig) isotypes, IgM, IgNAR and IgW. Newborn nurse sharks, Ginglymostoma cirratum, produce 19S (multimeric) IgM and monomeric/dimeric IgM1gj, a germline-joined, IgM-related VH, and very low amounts of 7S (monomeric) IgM and IgNAR proteins. Newborn IgNAR VH mRNAs are diverse in the complementarity-determining region 3 (CDR3) with non-templated nucleotide (N-region) addition, which suggests that, unlike in many other vertebrates, terminal deoxynucleotidyl transferase (TdT) expressed at birth is functional. IgW is present in the lungfish, a bony fish sharing a common ancestor with sharks 460 million years ago, implying that the IgW VH family is as old as the IgM VH family. This nurse shark study examined the IgM and IgW VH repertoire from birth through adult life, and analyzed the phylogenetic relationships of these gene families. Results IgM and IgW VH cDNA clones isolated from newborn nurse shark primary and secondary lymphoid tissues had highly diverse and unique CDR3 with N-region addition and VDJ gene rearrangement, implicating functional TdT and RAG gene activity. Despite the clear presence of N-region additions, newborn CDR3 were significantly shorter than those of adults. The IgM clones are all included in a conventional VH family that can be classified into five discrete groups, none of which is orthologous to IgM VH genes in other elasmobranchs. In addition, a novel divergent VH family was orthologous to a published monotypic VH horn shark family. IgW VH genes have diverged sufficiently to form three families. IgM and IgW VH serine codons using the potential somatic hypermutation hotspot sequence occur mainly in VH framework 1 (FR1) and CDR1. Phylogenetic analysis of cartilaginous fish and lungfish IgM and IgW demonstrated they form two major ancient gene groups; furthermore, these VH genes generally diversify (duplicate and diverge) within a species. Conclusion As in ratfish, sandbar and horn sharks, most nurse shark IgM VH genes are from one family with multiple, heterogeneous loci. Their IgW VH genes have diversified, forming at least three families. The neonatal shark Ig VH CDR3 repertoire, diversified via N-region addition, is shorter than the adult VDJ junction, suggesting one means of postnatal repertoire diversification is expression of longer CDR3 junctions.
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Affiliation(s)
- Lynn L Rumfelt
- Department of Microbiology and Immunology, University of Miami School of Medicine, Miami, FL 33101 USA
- Department of Immunology, University of Toronto, Sunnybrook & Women's College Health Sciences Centre, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5 Canada
| | - Rebecca L Lohr
- Department of Microbiology and Immunology, University of Maryland School of Medicine, 655 W. Baltimore St., Rm. BRB-13009, Baltimore, MD 21201 USA
| | - Helen Dooley
- Department of Microbiology and Immunology, University of Maryland School of Medicine, 655 W. Baltimore St., Rm. BRB-13009, Baltimore, MD 21201 USA
| | - Martin F Flajnik
- Department of Microbiology and Immunology, University of Miami School of Medicine, Miami, FL 33101 USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, 655 W. Baltimore St., Rm. BRB-13009, Baltimore, MD 21201 USA
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Ota T, Rast JP, Litman GW, Amemiya CT. Lineage-restricted retention of a primitive immunoglobulin heavy chain isotype within the Dipnoi reveals an evolutionary paradox. Proc Natl Acad Sci U S A 2003; 100:2501-6. [PMID: 12606718 PMCID: PMC151370 DOI: 10.1073/pnas.0538029100] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The lineage leading to lungfishes is one of the few major jawed vertebrate groups in which Ig heavy chain isotype structure has not been investigated at the genetic level. In this study, we have characterized three different Ig heavy chain isotypes of the African lungfish, Protopterus aethiopicus, including an IgM-type heavy chain and short and long forms of non-IgM heavy chains. Northern blot analysis as well as patterns of V(H) utilization suggest that the IgM and non-IgM isotypes are likely encoded in separate loci. The two non-IgM isotypes identified in Protopterus share structural features with the short and long forms of IgX/W/NARC (referred to hereafter as IgW), which were previously considered to be restricted to the cartilaginous fish. It seems that the IgW isotype has a far broader phylogenetic distribution than considered originally and raises questions with regard to the origin and evolutionary divergence of IgM and IgW. Moreover, its absence in other gnathostome lineages implies paradoxically that the IgW-type genes were lost from teleost and tetrapod lineages.
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Affiliation(s)
- Tatsuya Ota
- Department of Biosystems Science, The Graduate University for Advanced Studies (Sokendai), Hayama, Kanagawa 240-0193, Japan
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42
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Abstract
The study of immunoglobulin genes in non-mouse and non-human models has shown that different vertebrate groups have evolved distinct methods of generating antibody diversity. By contrast, the development of T cells in the thymus is quite similar in all of the species that have been examined. The three mechanisms by which B cells uniquely modify their immunoglobulin genes -- somatic hypermutation, gene conversion and class switching -- are increasingly believed to share some fundamental mechanisms, which studies in different vertebrate groups have helped (and will continue to help) to resolve. When these mechanisms are better understood, we should be able to look to the constitutive pathways from which they have evolved and perhaps determine whether the rearrangement of variable, diversity and joining antibody gene segments -- V(D)J recombination -- was superimposed on an existing adaptive immune system.
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Affiliation(s)
- Martin F Flajnik
- Department of Microbiology and Immunology, University of Maryland at Baltimore, Baltimore, Maryland 21201, USA.
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43
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Marchalonis JJ, Jensen I, Schluter SF. Structural, antigenic and evolutionary analyses of immunoglobulins and T cell receptors. J Mol Recognit 2002; 15:260-71. [PMID: 12447902 DOI: 10.1002/jmr.586] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
We have had the pleasure of collaborating with Allen Edmundson for the past 15 years on the structure, binding properties and evolution of immunoglobulins and T cell receptors. Among the most significant contributions of our joint efforts were: (1) the predictive use of structural features of immunoglobulin domains to model the three-dimensional structures of the immunoglobulin domains of human T-cell receptor alpha and beta chains as well as shark light chains and V(H) domains; (2) the finding that normal humans and other vertebrates express autoantibodies against combining site epitopes of their own T cell receptors; (3) the mapping of the peptide autoepitopes recognized in health, autoimmunity and retroviral infection; and (4) the determination that epitope recognition promiscuity is a characteristic property of the combining sites of IgM immunoglobulins ranging from those of sharks to those of humans. We briefly review the salient findings and status of these studies and indicate the future directions that we will pursue in their continuation.
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Affiliation(s)
- John J Marchalonis
- University of Arizona, Department of Microbiology and Immunology, College of Medicine, Tucson, AZ 85724, USA.
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Rumfelt LL, McKinney EC, Taylor E, Flajnik MF. The development of primary and secondary lymphoid tissues in the nurse shark Ginglymostoma cirratum: B-cell zones precede dendritic cell immigration and T-cell zone formation during ontogeny of the spleen. Scand J Immunol 2002; 56:130-48. [PMID: 12121433 DOI: 10.1046/j.1365-3083.2002.01116.x] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Secondary lymphoid tissue and immunoglobulin (Ig) production in mammals is not fully developed at birth, requiring time postnatally to attain all features required for adaptive immune responses. The immune system of newborn sharks - the oldest vertebrate group having adaptive immunity - also displays immature characteristics such as low serum IgM concentration and high levels of IgM1gj, an innate-like Ig. Primary and secondary lymphoid tissues in sharks and other cartilaginous fish were identified previously, but their cellular organization was not examined in detail. In this study of nurse shark lymphoid tissue, we demonstrate that the adult spleen contains well-defined, highly vascularized white pulp (WP) areas, composed of a central T-cell zone containing a major histocompatibility complex (MHC) class II+ dendritic cell (DC) network and a small number of Ig+ secretory cells, surrounded by smaller zones of surface Ig+ (sIg+) B cells. In neonates, splenic WPs are exclusively B-cell zones containing sIgM+-MHC class IIlow B cells; thus compartmentalized areas with T cells and DCs, as well as surface Ig novel antigen receptor (sIgNAR)-expressing B cells are absent at birth. Not until the pups are 5 months old do these WP areas become adult-like; concomitantly, sIgNAR+ B cells are readily detectable, indicating that this Ig class requires a 'mature immune-responsive environment'. The epigonal organ is the major site of neonatal B lymphopoiesis, based on the presence of developing B cells and recombination-activating gene 1 (RAG1)/terminal deoxynucleotidyl transferase (TdT) expression, indicative of antigen receptor rearrangement; such expression persists into adult life, whereas the spleen has negligible lymphopoietic activity. In adults but not neonates, many secretory B cells reside in the epigonal organ, suggesting, like in mammals, that B cells home to this primary lymphoid tissue after activation in other areas of the body.
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Affiliation(s)
- L L Rumfelt
- Department of Microbiology and Immunology, University of Miami School of Medicine, Miami, FL, USA
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Martin A. The phylogenetic placement of chondrichthyes: inferences from analysis of multiple genes and implications for comparative studies. Genetica 2002; 111:349-57. [PMID: 11841179 DOI: 10.1023/a:1013747532647] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Elasmobranch fishes (sharks and rays) have proven valuable for inferring general and specific properties of molecular evolution through comparative studies with crown group vertebrates because they are the most ancient group of gnathostomes. Recent studies have questioned the conventional phylogenetic placement of sharks in the vertebrate tree, however. In this paper I review the importance of the basal position of Chondrichthyes for comparative biology and compile evidence from multiple, independent genes to evaluate the phylogenetic placement of sharks. The results suggests that alternative phylogenetic hypotheses of the relationships among the Chondrichthyes, Actinopterygii and Sarcopterygii can not be refuted with available data, implying that the assumption of the basal placement of sharks in the vertebrate tree is suspect. Resolving the phylogeny of basal vertebrates is important for testing hypotheses about the evolution of vertebrates, and the current lack of a robust phylogeny limits evolutionary inferences that can be gained from comparative studies that include sharks and rays.
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Affiliation(s)
- A Martin
- Department of EPO Biology, University of Colorado, Boulder 80309, USA.
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Eason DD, Litman GW. Haplotype exclusion: the unique case presented by multiple immunoglobulin gene loci in cartilaginous fish. Semin Immunol 2002; 14:145-52; discussion 220. [PMID: 12160642 DOI: 10.1016/s1044-5323(02)00038-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cartilaginous fish represent the most phylogenetically distant species from man in which immunoglobulin and T cell antigen receptor genes have been identified. Immunoglobulin genes in cartilaginous fish are organized in hundreds of clusters, located on different chromosomes and presumably are under independent regulation; large numbers of immunoglobulin gene clusters are germline-joined and thus their expression is not directly dependent on somatic rearrangement. Despite the unusual nature of immunoglobulin gene genetics in these species, preliminary characterization of the transcription products of immunoglobulin loci in single cell isolates is consistent with haplotype exclusion. Certain features of immunoglobulin gene organization and expression in cartilaginous fish are remarkably similar to that of odorant receptors and suggest that at the level of transcriptional regulation, at least two different mechanisms could exist that relate to haplotype exclusion.
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Affiliation(s)
- Donna D Eason
- Department of Molecular Genetics, All Children's Hospital, St. Petersburg, FL 33701, USA
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Rumfelt LL, Avila D, Diaz M, Bartl S, McKinney EC, Flajnik MF. A shark antibody heavy chain encoded by a nonsomatically rearranged VDJ is preferentially expressed in early development and is convergent with mammalian IgG. Proc Natl Acad Sci U S A 2001; 98:1775-80. [PMID: 11172027 PMCID: PMC29333 DOI: 10.1073/pnas.98.4.1775] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2000] [Indexed: 11/18/2022] Open
Abstract
In most vertebrate embryos and neonates studied to date unique antigen receptors (antibodies and T cell receptors) are expressed that possess a limited immune repertoire. We have isolated a subclass of IgM, IgM(1gj), from the nurse shark Ginglymostoma cirratum that is preferentially expressed in neonates. The variable (V) region gene encoding the heavy (H) chain underwent V-D-J rearrangement in germ cells ("germline-joined"). Such H chain V genes were discovered over 10 years ago in sharks but until now were not shown to be expressed at appreciable levels; we find expression of H(1gj) in primary and secondary lymphoid tissues early in life, but in adults only in primary lymphoid tissue, which is identified in this work as the epigonal organ. H(1gj) chain associates covalently with light (L) chains and is most similar in sequence to IgM H chains, but like mammalian IgG has three rather than the four IgM constant domains; deletion of the ancestral IgM C2 domain thus defines both IgG and IgM(1gj). Because sharks are the members of the oldest vertebrate class known to possess antibodies, unique or specialized antibodies expressed early in ontogeny in sharks and other vertebrates were likely present at the inception of the adaptive immune system.
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Affiliation(s)
- L L Rumfelt
- Department of Microbiology and Immunology, University of Miami School of Medicine, P.O. Box 016960 (R-138), Miami, FL 33101, USA
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Abstract
Immunoglobulin gene diversity has been characterized to varying degrees in modern representatives of all of the major radiations of cartilaginous fish. A pattern of overall chromosomal relationships of the various types of joined and unjoined Ig gene clusters is suggested in which the essential features are: (a) both Ig heavy and light-chain gene clusters occur on multiple chromosomes, (b) various classes of Ig are interspersed, (c) not all individual gene loci appear to be closely linked (Fig. 2). The cluster-type Ig gene system appears to be a series of (potentially) individually regulated loci analogous in part to the olfactory receptor gene system (BUCK and AXEL 1991) and markedly distinct from Ig loci in other vertebrate groups and TCR genes. Such a system would be ideal for the creation of variation in both form and function in a large number of clusters while preserving or partially preserving specificity in a number of other gene clusters. The full range of joined genes and the relative number of joined genes (as relates to unjoined genes), have yet to be determined. Nevertheless, a number of conclusions can be drawn: (a) four distinct forms of heavy-chain joining have been identified (VDD-J, VD-DJ, V-D-DJ, and VDJ; Fig. 1); (b) light-chain genes, which possess only two recombining elements, can be found in either unjoined (V-J) or joined (VJ) forms (Fig. 1); (c) physical linkage between individual joined and unjoined genes has not been established, although such investigations have not been pursued in a significantly rigorous manner as to rule out this possibility; (d) joined light-chain genes are expressed and can be somatically mutated. Can germline joining be viewed as an ancestral character? The answer to this needs to be considered in the context of an overall system in which the level of structural and functional redundancy is extremely high. Joining is an adaptation that is unique to multicluster gene families. The phenomenon overcomes the possibility of not generating a specific form of a receptor, a major shortcoming of conventional rearranging Ig and TCR gene systems. The limitation of encoding specific receptors is compensated through large numbers of additional gene clusters that retain the capacity to rearrange and generate new specificities. Commitment of a V region to diverse, fixed specificity also is a property of the NITR genes, which although not related closely to Ig in a structural sense, may reflect an analogous phenomena. The possibility that immune-type diversity is achieved in the absence of somatic rearrangement and that remnants of such systems could be operative in immune recognition in contemporary vertebrates is of extraordinary significance in terms of our overall understanding of the relationships between adaptive and innate immune recognition.
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Affiliation(s)
- J A Yoder
- Moffitt Cancer Center, Department of Pediatrics, University of South Florida, All Children's Hospital, St. Petersburg 33701, USA
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Bengtén E, Wilson M, Miller N, Clem LW, Pilström L, Warr GW. Immunoglobulin isotypes: structure, function, and genetics. Curr Top Microbiol Immunol 2000; 248:189-219. [PMID: 10793479 DOI: 10.1007/978-3-642-59674-2_9] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- E Bengtén
- Department of Microbiology, University of Mississippi Medical Center, Jackson 39216-4505, USA
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Ota T, Sitnikova T, Nei M. Evolution of vertebrate immunoglobulin variable gene segments. Curr Top Microbiol Immunol 2000; 248:221-45. [PMID: 10793480 DOI: 10.1007/978-3-642-59674-2_10] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Evolution of Ig V gene segments are generally characterized by (a) evolution by "the birth and death process" and (b) diversifying selection. However, the detailed evolutionary pattern of V gene segments varies among species due to the fact that the humoral immune system itself has changed during vertebrate evolution. The change in somatic diversification system coupled with the change in lymphocyte development has imposed a significant impact on the evolution of Ig genes. In order to understand the evolution of immunological genes it is important to view it in the context of the evolution of the entire immune system itself.
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Affiliation(s)
- T Ota
- Center for Human Genetics, Boston University School of Medicine, MA 02118, USA.
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