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Devaux CA, Pontarotti P, Nehari S, Raoult D. 'Cannibalism' of exogenous DNA sequences: The ancestral form of adaptive immunity which entails recognition of danger. Front Immunol 2022; 13:989707. [PMID: 36618387 PMCID: PMC9816338 DOI: 10.3389/fimmu.2022.989707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 12/05/2022] [Indexed: 12/24/2022] Open
Abstract
Adaptive immunity is a sophisticated form of immune response capable of retaining the molecular memory of a very great diversity of target antigens (epitopes) as non-self. It is capable of reactivating itself upon a second encounter with an immunoglobulin or T-cell receptor antigen-binding site with a known epitope that had previously primed the host immune system. It has long been considered that adaptive immunity is a highly evolved form of non-self recognition that appeared quite late in speciation and complemented a more generalist response called innate immunity. Innate immunity offers a relatively non-specific defense (although mediated by sensors that could specifically recognize virus or bacteria compounds) and which does not retain a memory of the danger. But this notion of recent acquisition of adaptive immunity is challenged by the fact that another form of specific recognition mechanisms already existed in prokaryotes that may be able to specifically auto-protect against external danger. This recognition mechanism can be considered a primitive form of specific (adaptive) non-self recognition. It is based on the fact that many archaea and bacteria use a genome editing system that confers the ability to appropriate viral DNA sequences allowing prokaryotes to prevent host damage through a mechanism very similar to adaptive immunity. This is indistinctly called, 'endogenization of foreign DNA' or 'viral DNA predation' or, more pictorially 'DNA cannibalism'. For several years evidence has been accumulating, highlighting the crucial role of endogenization of foreign DNA in the fundamental processes related to adaptive immunity and leading to a change in the dogma that adaptive immunity appeared late in speciation.
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Affiliation(s)
- Christian A. Devaux
- Aix-Marseille University, Institut de recherche pour le développement (IRD), Assistance Publique Hôpitaux de Marseille (APHM), MEPHI, Institut Hospitalo-universitaire (IHU)-Méditerranée Infection, Marseille, France,Department of Biological Sciences, Centre National de la Recherche Scientifique, Centre National de la Recherche Scientifique (CNRS)-SNC5039, Marseille, France,*Correspondence: Christian A. Devaux,
| | - Pierre Pontarotti
- Aix-Marseille University, Institut de recherche pour le développement (IRD), Assistance Publique Hôpitaux de Marseille (APHM), MEPHI, Institut Hospitalo-universitaire (IHU)-Méditerranée Infection, Marseille, France,Department of Biological Sciences, Centre National de la Recherche Scientifique, Centre National de la Recherche Scientifique (CNRS)-SNC5039, Marseille, France
| | - Sephora Nehari
- Aix-Marseille University, Institut de recherche pour le développement (IRD), Assistance Publique Hôpitaux de Marseille (APHM), MEPHI, Institut Hospitalo-universitaire (IHU)-Méditerranée Infection, Marseille, France
| | - Didier Raoult
- Aix-Marseille University, Institut de recherche pour le développement (IRD), Assistance Publique Hôpitaux de Marseille (APHM), MEPHI, Institut Hospitalo-universitaire (IHU)-Méditerranée Infection, Marseille, France
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2
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Dornburg A, Yoder JA. On the relationship between extant innate immune receptors and the evolutionary origins of jawed vertebrate adaptive immunity. Immunogenetics 2022; 74:111-128. [PMID: 34981186 DOI: 10.1007/s00251-021-01232-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 11/01/2021] [Indexed: 01/17/2023]
Abstract
For over half a century, deciphering the origins of the genomic loci that form the jawed vertebrate adaptive immune response has been a major topic in comparative immunogenetics. Vertebrate adaptive immunity relies on an extensive and highly diverse repertoire of tandem arrays of variable (V), diversity (D), and joining (J) gene segments that recombine to produce different immunoglobulin (Ig) and T cell receptor (TCR) genes. The current consensus is that a recombination-activating gene (RAG)-like transposon invaded an exon of an ancient innate immune VJ-bearing receptor, giving rise to the extant diversity of Ig and TCR loci across jawed vertebrates. However, a model for the evolutionary relationships between extant non-recombining innate immune receptors and the V(D)J receptors of the jawed vertebrate adaptive immune system has only recently begun to come into focus. In this review, we provide an overview of non-recombining VJ genes, including CD8β, CD79b, natural cytotoxicity receptor 3 (NCR3/NKp30), putative remnants of an antigen receptor precursor (PRARPs), and the multigene family of signal-regulatory proteins (SIRPs), that play a wide range of roles in immune function. We then focus in detail on the VJ-containing novel immune-type receptors (NITRs) from ray-finned fishes, as recent work has indicated that these genes are at least 50 million years older than originally thought. We conclude by providing a conceptual model of the evolutionary origins and phylogenetic distribution of known VJ-containing innate immune receptors, highlighting opportunities for future comparative research that are empowered by this emerging evolutionary perspective.
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Affiliation(s)
- Alex Dornburg
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, NC, USA.
| | - Jeffrey A Yoder
- Department of Molecular Biomedical Sciences, North Carolina State University, 1060 William Moore Drive, Raleigh, NC, USA.
- Comparative Medicine Institute, North Carolina State University, Raleigh, NC, USA.
- Center for Human Health and the Environment, North Carolina State University, Raleigh, NC, USA.
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3
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Zhou J, Xiao Z, Zhan Y, Qu X, Mou S, Deng C, Zhang T, Lan X, Huang S, Li Y. Identification and Characterization of the Amphioxus Lck and Its Associated Tyrosine Phosphorylation-Dependent Inhibitory LRR Receptor. Front Immunol 2021; 12:656366. [PMID: 34149695 PMCID: PMC8211107 DOI: 10.3389/fimmu.2021.656366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 05/17/2021] [Indexed: 11/13/2022] Open
Abstract
Amphioxus (e.g., Branchiostoma belcheri, Bb) has recently emerged as a new model for studying the origin and evolution of vertebrate immunity. Mammalian lymphocyte-specific tyrosine kinase (Lck) plays crucial roles in T cell activation, differentiation and homeostasis, and is reported to phosphorylate both the ITIM and ITSM of PD-1 to induce the recruitment of phosphatases and thus the inhibitory function of PD-1. Here, we identified and cloned the amphioxus homolog of human Lck. By generating and using an antibody against BbLck, we found that BbLck is expressed in the amphioxus gut and gill. Through overexpression of BbLck in Jurkat T cells, we found that upon TCR stimulation, BbLck was subjected to tyrosine phosphorylation and could partially rescue Lck-dependent tyrosine phosphorylation in Lck-knockdown T cells. Mass spectrometric analysis of BbLck immunoprecipitates from immunostimulants-treated amphioxus, revealed a BbLck-associated membrane-bound receptor LRR (BbLcLRR). By overexpressing BbLcLRR in Jurkat T cells, we demonstrated that BbLcLRR was tyrosine phosphorylated upon TCR stimulation, which was inhibited by Lck knockdown and was rescued by overexpression of BbLck. By mutating single tyrosine to phenylalanine (Y-F), we identified three tyrosine residues (Y539, Y655, and Y690) (3Y) of BbLcLRR as the major Lck phosphorylation sites. Reporter gene assays showed that overexpression of BbLcLRR but not the BbLcLRR-3YF mutant inhibited TCR-induced NF-κB activation. In Lck-knockdown T cells, the decline of TCR-induced IL-2 production was reversed by overexpression of BbLck, and this reversion was inhibited by co-expression of BbLcLRR but not the BbLcLRR-3YF mutant. Sequence analysis showed that the three tyrosine-containing sequences were conserved with the tyrosine-based inhibition motifs (ITIMs) or ITIM-like motifs. And TCR stimulation induced the association of BbLcLRR with tyrosine phosphatases SHIP1 and to a lesser extent with SHP1/2. Moreover, overexpression of wild-type BbLcLRR but not its 3YF mutant inhibited TCR-induced tyrosine phosphorylation of multiple signaling proteins probably via recruiting SHIP1. Thus, we identified a novel immunoreceptor BbLcLRR, which is phosphorylated by Lck and then exerts a phosphorylation-dependent inhibitory role in TCR-mediated T-cell activation, implying a mechanism for the maintenance of self-tolerance and homeostasis of amphioxus immune system and the evolutionary conservatism of Lck-regulated inhibitory receptor pathway.
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Affiliation(s)
- Jiatao Zhou
- Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Zhihui Xiao
- Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yanli Zhan
- Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Xuemei Qu
- Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Sisi Mou
- Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Chong Deng
- Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Tianxiang Zhang
- Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Xin Lan
- Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Shengfeng Huang
- Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yingqiu Li
- Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
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4
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Oreste U, Ametrano A, Coscia MR. On Origin and Evolution of the Antibody Molecule. BIOLOGY 2021; 10:biology10020140. [PMID: 33578914 PMCID: PMC7916673 DOI: 10.3390/biology10020140] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 02/05/2021] [Accepted: 02/07/2021] [Indexed: 12/29/2022]
Abstract
Simple Summary Like many other molecules playing vital functions in animals, the antibody molecule possesses a complex structure with distinctive features. The structure of the basic unit, i.e., the immunoglobulin domain of very ancient origin is substantially simple. However, high complexity resides in the types and numbers of the domains composing the whole molecule. The emergence of the antibody molecule during evolution overturned the effectiveness of the organisms’ defense system. The particular organization of the coding genes, the mechanisms generating antibody diversity, and the plasticity of the overall protein structure, attest to an extraordinary successful evolutionary history. Here, we attempt to trace, across the evolutionary scale, the very early origins of the most significant features characterizing the structure of the antibody molecule and of the molecular mechanisms underlying its major role in recognizing an almost unlimited number of pathogens. Abstract The vertebrate immune system provides a powerful defense because of the ability to potentially recognize an unlimited number of pathogens. The antibody molecule, also termed immunoglobulin (Ig) is one of the major mediators of the immune response. It is built up from two types of Ig domains: the variable domain, which provides the capability to recognize and bind a potentially infinite range of foreign substances, and the constant domains, which exert the effector functions. In the last 20 years, advances in our understanding of the molecular mechanisms and structural features of antibody in mammals and in a variety of other organisms have uncovered the underlying principles and complexity of this fundamental molecule. One notable evolutionary topic is the origin and evolution of antibody. Many aspects have been clearly stated, but some others remain limited or obscure. By considering a wide range of prokaryotic and eukaryotic organisms through a literature survey about the topic, we have provided an integrated view of the emergence of antibodies in evolution and underlined the very ancient origins.
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Affiliation(s)
- Umberto Oreste
- Institute of Biochemistry and Cell Biology, National Research Council of Italy, Via P. Castellino, 111, 80131 Naples, Italy; (U.O.); (A.A.)
| | - Alessia Ametrano
- Institute of Biochemistry and Cell Biology, National Research Council of Italy, Via P. Castellino, 111, 80131 Naples, Italy; (U.O.); (A.A.)
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania Luigi Vanvitelli, 81100 Caserta, Italy
| | - Maria Rosaria Coscia
- Institute of Biochemistry and Cell Biology, National Research Council of Italy, Via P. Castellino, 111, 80131 Naples, Italy; (U.O.); (A.A.)
- Correspondence: ; Tel.: +39-081-6132556
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5
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Trancoso I, Morimoto R, Boehm T. Co-evolution of mutagenic genome editors and vertebrate adaptive immunity. Curr Opin Immunol 2020; 65:32-41. [PMID: 32353821 PMCID: PMC7768089 DOI: 10.1016/j.coi.2020.03.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 02/18/2020] [Accepted: 03/02/2020] [Indexed: 12/28/2022]
Abstract
The adaptive immune systems of all vertebrates rely on self-DNA mutating enzymes to assemble their antigen receptors in lymphocytes of their two principal lineages. In jawed vertebrates, the RAG1/2 recombinase directs V(D)J recombination of B cell and T cell receptor genes, whereas the activation-induced cytidine deaminase AID engages in their secondary modification. The recombination activating genes (RAG) 1 and 2 evolved from an ancient transposon-encoded genome modifier into a self-DNA mutator serving adaptive immunity; this was possible as a result of domestication, involving several changes in RAG1 and RAG2 proteins suppressing transposition and instead facilitating-coupled cleavage and recombination. By contrast, recent evidence supports the notion that the antigen receptors of T-like and B-like cells of jawless vertebrates, designated variable lymphocyte receptors (VLRs), are somatically assembled through a process akin to gene conversion that is believed to be dependent on the activities of distant relatives of AID, the cytidine deaminases CDA1 and CDA2, respectively. It appears, therefore, that the precursors of AID and CDAs underwent a domestication process that changed their target range from foreign nucleic acids to self-DNA; this multi-step evolutionary process ensured that the threat to host genome integrity was minimized. Here, we review recent findings illuminating the evolutionary steps associated with the domestication of the two groups of genome editors, RAG1/2 and cytidine deaminases, indicating how they became the driving forces underlying the emergence of vertebrate adaptive immune systems.
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Affiliation(s)
- Inês Trancoso
- Department of Developmental Immunology, Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg, Germany
| | - Ryo Morimoto
- Department of Developmental Immunology, Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg, Germany
| | - Thomas Boehm
- Department of Developmental Immunology, Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg, Germany.
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6
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Sun A, Xu K, Liu H, Li H, Shi Y, Zhu X, Liang T, Li X, Cao X, Ji Y, Jiang T, Xu C, Liu X. The evolution of zebrafish RAG2 protein is required for adapting to the elevated body temperature of the higher endothermic vertebrates. Sci Rep 2020; 10:4126. [PMID: 32139788 PMCID: PMC7057966 DOI: 10.1038/s41598-020-61019-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 02/19/2020] [Indexed: 11/21/2022] Open
Abstract
The recombination activating gene (RAG or RAG1/RAG2 complex)-mediated adaptive immune system is a hallmark of jawed vertebrates. It has been reported that RAG originated in invertebrates. However, whether RAG further evolved once it arose in jawed vertebrates remains largely unknown. Here, we found that zebrafish RAG (zRAG) had a lower activity than mouse RAG (mRAG). Intriguingly, the attenuated stability of zebrafish RAG2 (zRAG2), but not zebrafish RAG1, caused the reduced V(D)J recombination efficiency compared to mRAG at 37 °C which are the body temperature of most endotherms except birds. Importantly, the lower temperature 28 °C, which is the best temperature for zebrafish growth, made the recombination efficiency of zRAG similar to that of mRAG by improving the stability of zRAG2. Consistent with the prementioned observation, the V(D)J recombination of Rag2KI/KI mice, which zRAG2 was substituted for mRAG2, was also severely impaired. Unexpectedly, Rag2KI/KI mice developed cachexia syndromes accompanied by premature death. Taken together, our findings illustrate that the evolution of zebrafish RAG2 protein is required for adapting to the elevated body temperature of the higher endothermic vertebrates.
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Affiliation(s)
- Ao Sun
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200031, China
| | - Ke Xu
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200031, China
| | - Haifeng Liu
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200031, China
| | - Hua Li
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200031, China
| | - Yaohuang Shi
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200031, China.,School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Xiaoyan Zhu
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200031, China
| | - Tao Liang
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200031, China
| | - Xinyue Li
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200031, China
| | - Xianxia Cao
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200031, China.,School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Yanhong Ji
- Department of Pathogenic Biology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Centre, Xi'an, Shaanxi, 710061, China
| | - Taijiao Jiang
- Center of System Medicine, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100005, China
| | - Chenqi Xu
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200031, China
| | - Xiaolong Liu
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200031, China. .,School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
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7
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Tao X, Yuan S, Chen F, Gao X, Wang X, Yu W, Liu S, Huang Z, Chen S, Xu A. Functional requirement of terminal inverted repeats for efficient ProtoRAG activity reveals the early evolution of V(D)J recombination. Natl Sci Rev 2020; 7:403-417. [PMID: 34692056 PMCID: PMC8289069 DOI: 10.1093/nsr/nwz179] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 10/31/2019] [Accepted: 11/08/2019] [Indexed: 11/30/2022] Open
Abstract
The discovery of ProtoRAG in amphioxus indicated that vertebrate RAG recombinases originated from an ancient transposon. However, the sequences of ProtoRAG terminal inverted repeats (TIRs) were obviously dissimilar to the consensus sequence of mouse 12/23RSS and recombination mediated by ProtoRAG or RAG made them incompatible with each other. Thus, it is difficult to determine whether or how 12/23RSS persisted in the vertebrate RAG system that evolved from the TIRs of ancient RAG transposons. Here, we found that the activity of ProtoRAG is highly dependent on its asymmetric 5′TIR and 3′TIR, which are composed of conserved TR1 and TR5 elements and a partially conserved TRsp element of 27/31 bp to separate them. Similar to the requirements for the recombination signal sequences (RSSs) of RAG recombinase, the first CAC in TR1, the three dinucleotides in TR5 and the specific length of the partially conserved TRsp are important for the efficient recombination activity of ProtoRAG. In addition, the homologous sequences flanking the signal sequences facilitate ProtoRAG- but not RAG-mediated recombination. In addition to the diverged TIRs, two differentiated functional domains in BbRAG1L were defined to coordinate with the divergence between TIRs and RSSs. One of these is the CTT* domain, which facilitates the specific TIR recognition of the BbRAGL complex, and the other is NBD*, which is responsible for DNA binding and the protein stabilization of the BbRAGL complex. Thus, our findings reveal that the functional requirement for ProtoRAG TIRs is similar to that for RSS in RAG-mediated recombination, which not only supports the common origin of ProtoRAG TIRs and RSSs from the asymmetric TIRs of ancient RAG transposons, but also reveals the development of RAG and RAG-like machineries during chordate evolution.
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Affiliation(s)
- Xin Tao
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Shaochun Yuan
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Fan Chen
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Xiaoman Gao
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Xinli Wang
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Wenjuan Yu
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Song Liu
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Ziwen Huang
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Shangwu Chen
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Anlong Xu
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.,School of Life Sciences, Beijing University of Chinese Medicine, Beijing 100029, China
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8
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Abstract
The origins of the various elements in the human antibody repertoire have been and still are subject to considerable uncertainty. Uncertainty in respect of whether the various elements have always served a specific defense function or whether they were co-opted from other organismal roles to form a crude naïve repertoire that then became more complex as combinatorial mechanisms were added. Estimates of the current size of the human antibody naïve repertoire are also widely debated with numbers anywhere from 10 million members, based on experimentally derived numbers, to in excess of one thousand trillion members or more, based on the different sequences derived from theoretical combinatorial calculations. There are questions that are relevant at both ends of this number spectrum. At the lower bound it could be questioned whether this is an insufficient repertoire size to counter all the potential antigen-bearing pathogens. At the upper bound the question is rather simpler: How can any individual interrogate such an astronomical number of antibody-bearing B cells in a timeframe that is meaningful? This review evaluates the evolutionary aspects of the adaptive immune system, the calculations that lead to the large repertoire estimates, some of the experimental evidence pointing to a more restricted repertoire whose variation appears to derive from convergent 'structure and specificity features', and includes a theoretical model that seems to support it. Finally, a solution that may reconcile the size difference anomaly, which is still a hot subject of debate, is suggested.
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9
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Zhang QL, Zhu QH, Liang MZ, Wang F, Guo J, Deng XY, Chen JY, Wang YJ, Lin LB. Comparative transcriptomic analysis provides insights into antibacterial mechanisms of Branchiostoma belcheri under Vibrio parahaemolyticus infection. FISH & SHELLFISH IMMUNOLOGY 2018; 76:196-205. [PMID: 29510259 DOI: 10.1016/j.fsi.2018.03.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 02/24/2018] [Accepted: 03/02/2018] [Indexed: 06/08/2023]
Abstract
UNLABELLED Amphioxus, a basal chordate, is widely considered to be an existing proxy of the invertebrate ancestor of vertebrates, and it exhibits susceptibility to various pathogen infections and pathogenic mimic challenges. Here, in order to understand more clearly its antibacterial mechanisms, we analyzed the ribosomal RNA (rRNA)-depleted transcriptome of Chinese amphioxus (Branchiostoma belcheri) infected with Vibrio parahaemolyticus (V. p.) via next-generation deep sequencing technology (RNA-seq). We identified a total of 3214 differentially expressed genes (DEGs) by comparing V. p.-infected and control transcriptome libraries, including 2219 significantly up-regulated and 995 significantly down-regulated DEGs in V. p.-infected amphioxus. The DEGs with the top 10 most dramatic expression fold changes after V. p. infection, as well as 53 immune-related DEGs (IRDs) belonging to four primary categories of innate immunity were analyzed further. Through gene ontology (GO) and pathway enrichment analysis, DEGs were found to be primarily related to immune processes, apoptosis, catabolic and metabolic processes, binding and enzyme activity, while pathways involving bacterial infection, immune signaling, immune response, cancer, and apoptosis were overrepresented. We validated the RNA-seq results by detecting the expression levels of 10 IRDs using qRT-PCR, and we surveyed the dynamic variation in gene expression for these IRDs at 0, 6, 12, 24, and 48 h after V. p. TREATMENT Subsequently, according to the RNA-seq results, the presence of a primitive Toll-like receptor (TLR)-mediated antibacterial immune signaling pathway was predicted in B. belcheri. This study provides valuable information regarding antibacterial immunity for further research into the evolution of immunity in vertebrates and broadens our understanding of the innate immune response against bacterial invasion in amphioxus.
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Affiliation(s)
- Qi-Lin Zhang
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500, China; State Key Laboratory of Pharmaceutical Biotechnology, School of Life Science, Nanjing University, Nanjing, 210023, China
| | - Qian-Hua Zhu
- BGI Genomics, BGI-Shenzhen, Shenzhen, 518083, China
| | - Ming-Zhong Liang
- Department of Marine Science, Qinzhou University, Qinzhou, 535000, China
| | - Feng Wang
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500, China
| | - Jun Guo
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500, China
| | - Xian-Yu Deng
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500, China
| | - Jun-Yuan Chen
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Science, Nanjing University, Nanjing, 210023, China
| | - Yu-Jun Wang
- Department of Marine Science, Qinzhou University, Qinzhou, 535000, China.
| | - Lian-Bing Lin
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500, China.
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10
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Chen R, Zhang L, Qi J, Zhang N, Zhang L, Yao S, Wu Y, Jiang B, Wang Z, Yuan H, Zhang Q, Xia C. Discovery and Analysis of Invertebrate IgV J-C2 Structure from Amphioxus Provides Insight into the Evolution of the Ig Superfamily. THE JOURNAL OF IMMUNOLOGY 2018. [PMID: 29514951 DOI: 10.4049/jimmunol.1700906] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The emergence of adaptive immunity in jawed vertebrates depended on the appearance of variable immune receptors, BCRs and TCRs, which exhibit variable-J-constant (VJ-C)-type Ig superfamily folds. Hitherto, however, the structures of IgV-J-IgC-type molecules had never been characterized in invertebrates, leaving the origin of BCR/TCR-type molecules unknown. Using x-ray crystallography, the structure of a VJ-C2 molecule, named AmpIgVJ-C2, was determined in amphioxus (Branchiostoma floridae). The first domain shows typical V folding, including the hydrophobic core, CDR analogs, and eight conserved residues. The second domain is a C2-type Ig superfamily domain, as defined by its short length and the absence of β-strand D- and C1-typical motifs. AmpIgVJ-C2 molecules form homodimers, using "three-layer packing dimerization," as described for TCRs and BCRs. The AmpIgVJ-C2 V domain harbors a diglycine motif in β-strand G and forms a β-bulge structure participating in V-V intermolecular interaction. By immunohistochemistry, AmpIgVJ-C2 molecules were primarily found in mucosal tissues, whereas PCR and sequence analysis indicated considerable genetic variation at the single-gene level; these findings would be consistent with an immune function and a basic ability to adapt to binding different immune targets. Our results show a BCR/TCR-ancestral like molecule in amphioxus and help us to understand the evolution of the adaptive immune system.
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Affiliation(s)
- Rong Chen
- Department of Microbiology and Immunology, College of Veterinary Medicine, China Agricultural University, Haidian District, Beijing 100094, China.,Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, National Center for Engineering Research of Veterinary Bio-products, Xuanwu District, Nanjing 210014, China
| | - Lijie Zhang
- Department of Microbiology and Immunology, College of Veterinary Medicine, China Agricultural University, Haidian District, Beijing 100094, China
| | - Jianxun Qi
- Chinese Academy of Sciences Key Laboratory of Pathogenic Microbiology Immunology, Institute of Microbiology, Chinese Academy of Sciences, Chaoyang District, Beijing 100101, China
| | - Nianzhi Zhang
- Department of Microbiology and Immunology, College of Veterinary Medicine, China Agricultural University, Haidian District, Beijing 100094, China
| | - Ling Zhang
- Department of Microbiology and Immunology, College of Veterinary Medicine, China Agricultural University, Haidian District, Beijing 100094, China
| | - Shugang Yao
- Department of Microbiology and Immunology, College of Veterinary Medicine, China Agricultural University, Haidian District, Beijing 100094, China
| | - Yanan Wu
- Department of Microbiology and Immunology, College of Veterinary Medicine, China Agricultural University, Haidian District, Beijing 100094, China
| | - Bo Jiang
- Department of Microbiology and Immunology, College of Veterinary Medicine, China Agricultural University, Haidian District, Beijing 100094, China
| | - Zhenbao Wang
- Department of Microbiology and Immunology, College of Veterinary Medicine, China Agricultural University, Haidian District, Beijing 100094, China
| | - Hongyu Yuan
- Department of Microbiology and Immunology, College of Veterinary Medicine, China Agricultural University, Haidian District, Beijing 100094, China
| | - Qiujin Zhang
- College of Life Sciences, Fujian Normal University, Fujian 350117, China; and
| | - Chun Xia
- Department of Microbiology and Immunology, College of Veterinary Medicine, China Agricultural University, Haidian District, Beijing 100094, China; .,Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Haidian District, Beijing 100094, China
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11
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Boehm T, Hirano M, Holland SJ, Das S, Schorpp M, Cooper MD. Evolution of Alternative Adaptive Immune Systems in Vertebrates. Annu Rev Immunol 2017; 36:19-42. [PMID: 29144837 DOI: 10.1146/annurev-immunol-042617-053028] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Adaptive immunity in jawless fishes is based on antigen recognition by three types of variable lymphocyte receptors (VLRs) composed of variable leucine-rich repeats, which are differentially expressed by two T-like lymphocyte lineages and one B-like lymphocyte lineage. The T-like cells express either VLRAs or VLRCs of yet undefined antigen specificity, whereas the VLRB antibodies secreted by B-like cells bind proteinaceous and carbohydrate antigens. The incomplete VLR germline genes are assembled into functional units by a gene conversion-like mechanism that employs flanking variable leucine-rich repeat sequences as templates in association with lineage-specific expression of cytidine deaminases. B-like cells develop in the hematopoietic typhlosole and kidneys, whereas T-like cells develop in the thymoid, a thymus-equivalent region at the gill fold tips. Thus, the dichotomy between T-like and B-like cells and the presence of dedicated lymphopoietic tissues emerge as ancestral vertebrate features, whereas the somatic diversification of structurally distinct antigen receptor genes evolved independently in jawless and jawed vertebrates.
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Affiliation(s)
- Thomas Boehm
- Department of Developmental Immunology, Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg, Germany; , ,
| | - Masayuki Hirano
- Emory Vaccine Center and Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia 30322, USA; , ,
| | - Stephen J Holland
- Department of Developmental Immunology, Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg, Germany; , ,
| | - Sabyasachi Das
- Emory Vaccine Center and Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia 30322, USA; , ,
| | - Michael Schorpp
- Department of Developmental Immunology, Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg, Germany; , ,
| | - Max D Cooper
- Emory Vaccine Center and Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia 30322, USA; , ,
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12
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Müller V, de Boer RJ, Bonhoeffer S, Szathmáry E. An evolutionary perspective on the systems of adaptive immunity. Biol Rev Camb Philos Soc 2017; 93:505-528. [PMID: 28745003 DOI: 10.1111/brv.12355] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 06/28/2017] [Accepted: 06/30/2017] [Indexed: 12/22/2022]
Abstract
We propose an evolutionary perspective to classify and characterize the diverse systems of adaptive immunity that have been discovered across all major domains of life. We put forward a new function-based classification according to the way information is acquired by the immune systems: Darwinian immunity (currently known from, but not necessarily limited to, vertebrates) relies on the Darwinian process of clonal selection to 'learn' by cumulative trial-and-error feedback; Lamarckian immunity uses templated targeting (guided adaptation) to internalize heritable information on potential threats; finally, shotgun immunity operates through somatic mechanisms of variable targeting without feedback. We argue that the origin of Darwinian (but not Lamarckian or shotgun) immunity represents a radical innovation in the evolution of individuality and complexity, and propose to add it to the list of major evolutionary transitions. While transitions to higher-level units entail the suppression of selection at lower levels, Darwinian immunity re-opens cell-level selection within the multicellular organism, under the control of mechanisms that direct, rather than suppress, cell-level evolution for the benefit of the individual. From a conceptual point of view, the origin of Darwinian immunity can be regarded as the most radical transition in the history of life, in which evolution by natural selection has literally re-invented itself. Furthermore, the combination of clonal selection and somatic receptor diversity enabled a transition from limited to practically unlimited capacity to store information about the antigenic environment. The origin of Darwinian immunity therefore comprises both a transition in individuality and the emergence of a new information system - the two hallmarks of major evolutionary transitions. Finally, we present an evolutionary scenario for the origin of Darwinian immunity in vertebrates. We propose a revival of the concept of the 'Big Bang' of vertebrate immunity, arguing that its origin involved a 'difficult' (i.e. low-probability) evolutionary transition that might have occurred only once, in a common ancestor of all vertebrates. In contrast to the original concept, we argue that the limiting innovation was not the generation of somatic diversity, but the regulatory circuitry needed for the safe operation of amplifiable immune responses with somatically acquired targeting. Regulatory complexity increased abruptly by genomic duplications at the root of the vertebrate lineage, creating a rare opportunity to establish such circuitry. We discuss the selection forces that might have acted at the origin of the transition, and in the subsequent stepwise evolution leading to the modern immune systems of extant vertebrates.
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Affiliation(s)
- Viktor Müller
- Parmenides Center for the Conceptual Foundations of Science, 82049 Pullach/Munich, Germany.,Department of Plant Systematics, Ecology and Theoretical Biology, Institute of Biology, Eötvös Loránd University, 1117 Budapest, Hungary.,Evolutionary Systems Research Group, MTA Centre for Ecological Research, 8237 Tihany, Hungary
| | - Rob J de Boer
- Theoretical Biology, Department of Biology, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Sebastian Bonhoeffer
- Institute of Integrative Biology, Department of Environmental Systems Science, ETH Zurich, 8092 Zurich, Switzerland
| | - Eörs Szathmáry
- Parmenides Center for the Conceptual Foundations of Science, 82049 Pullach/Munich, Germany.,Department of Plant Systematics, Ecology and Theoretical Biology, Institute of Biology, Eötvös Loránd University, 1117 Budapest, Hungary.,Evolutionary Systems Research Group, MTA Centre for Ecological Research, 8237 Tihany, Hungary
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13
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Carmona LM, Schatz DG. New insights into the evolutionary origins of the recombination-activating gene proteins and V(D)J recombination. FEBS J 2017; 284:1590-1605. [PMID: 27973733 PMCID: PMC5459667 DOI: 10.1111/febs.13990] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 11/10/2016] [Accepted: 12/08/2016] [Indexed: 12/26/2022]
Abstract
The adaptive immune system of jawed vertebrates relies on V(D)J recombination as one of the main processes to generate the diverse array of receptors necessary for the recognition of a wide range of pathogens. The DNA cleavage reaction necessary for the assembly of the antigen receptor genes from an array of potential gene segments is mediated by the recombination-activating gene proteins RAG1 and RAG2. The RAG proteins have been proposed to originate from a transposable element (TE) as they share mechanistic and structural similarities with several families of transposases and are themselves capable of mediating transposition. A number of RAG-like proteins and TEs with sequence similarity to RAG1 and RAG2 have been identified, but only recently has their function begun to be characterized, revealing mechanistic links to the vertebrate RAGs. Of particular significance is the discovery of ProtoRAG, a transposon superfamily found in the genome of the basal chordate amphioxus. ProtoRAG has many of the sequence and mechanistic features predicted for the ancestral RAG transposon and is likely to be an evolutionary relative of RAG1 and RAG2. In addition, early observations suggesting that RAG1 is able to mediate V(D)J recombination in the absence of RAG2 have been confirmed, implying independent evolutionary origins for the two RAG genes. Here, recent progress in identifying and characterizing RAG-like proteins and the TEs that encode them is summarized and a refined model for the evolution of V(D)J recombination and the RAG proteins is presented.
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Affiliation(s)
- Lina Marcela Carmona
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT, USA
| | - David G Schatz
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT, USA.,Howard Hughes Medical Institute, New Haven, CT, USA
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14
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Lescale C, Deriano L. The RAG recombinase: Beyond breaking. Mech Ageing Dev 2016; 165:3-9. [PMID: 27863852 DOI: 10.1016/j.mad.2016.11.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 11/04/2016] [Accepted: 11/11/2016] [Indexed: 11/17/2022]
Abstract
DNA double-strand breaks (DSBs) are commonly seen as lesions that threaten genome integrity and contribute to cancer and aging processes. However, in the context of antigen receptor gene assembly, known as V(D)J recombination, DSBs are obligatory intermediates that allow the establishment of genetic diversity and adaptive immunity. V(D)J recombination is initiated when the lymphoid-restricted recombination-activating genes RAG1 and RAG2 are expressed and form a site-specific endonuclease (the RAG nuclease or RAG recombinase). Here, we discuss the ability of the RAG nuclease to minimize the risks of genome disruption by coupling the breakage and repair steps of the V(D)J reaction. This implies that the RAG genes, derived from an ancient transposon, have undergone strong selective pressure to prohibit transposition in favor of promoting controlled DNA end joining in cis by the ubiquitous DNA damage response and DNA repair machineries. We also discuss the idea that, in addition to being essential for the rearrangement of antigen receptor genes, RAG-mediated DSBs could impact cellular processes and outcomes by affecting genetic and epigenetic programs.
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Affiliation(s)
- Chloé Lescale
- Department of Immunology and Department of Genomes and Genetics, Institut Pasteur, 75015 Paris, France
| | - Ludovic Deriano
- Department of Immunology and Department of Genomes and Genetics, Institut Pasteur, 75015 Paris, France.
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15
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Rodgers KK. Riches in RAGs: Revealing the V(D)J Recombinase through High-Resolution Structures. Trends Biochem Sci 2016; 42:72-84. [PMID: 27825771 DOI: 10.1016/j.tibs.2016.10.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 10/04/2016] [Accepted: 10/17/2016] [Indexed: 12/15/2022]
Abstract
Development of the adaptive immune system is dependent on V(D)J recombination, which forms functional antigen receptor genes through rearrangement of component gene segments. The V(D)J recombinase, comprising recombination-activating proteins RAG1 and RAG2, guides the initial DNA cleavage events to the recombination signal sequence (RSS), which flanks each gene segment. Although the enzymatic steps for RAG-mediated endonucleolytic activity were established over two decades ago, only recently have high-resolution structural studies of the catalytically active core regions of the RAG proteins shed light on conformational requirements for the reaction. While outstanding questions remain, we have a clearer picture of how RAG proteins function in generating the diverse repertoires of antigen receptors, the underlying foundation of the adaptive immune system.
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Affiliation(s)
- Karla K Rodgers
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73190, USA.
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16
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Abstract
Diversity of antibodies and T cell receptors is generated by gene rearrangement dependent on RAG1 and RAG2, enzymes predicted to have been derived from a transposable element (TE) that invaded an immunoglobulin superfamily gene early in the evolution of jawed vertebrates. Now, Huang et al. report the discovery of ProtoRAG in the lower chordate Amphioxus, the long-anticipated TE related to the RAG transposon.
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17
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Milutinović B, Kurtz J. Immune memory in invertebrates. Semin Immunol 2016; 28:328-42. [PMID: 27402055 DOI: 10.1016/j.smim.2016.05.004] [Citation(s) in RCA: 159] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 05/11/2016] [Accepted: 05/17/2016] [Indexed: 12/21/2022]
Abstract
Evidence for innate immune memory (or 'priming') in invertebrates has been accumulating over the last years. We here provide an in-depth review of the current state of evidence for immune memory in invertebrates, and in particular take a phylogenetic viewpoint. Invertebrates are a very heterogeneous group of animals and accordingly, evidence for the phenomenon of immune memory as well as the hypothesized molecular underpinnings differ largely for the diverse invertebrate taxa. The majority of research currently focuses on Arthropods, while evidence from many other groups of invertebrates is fragmentary or even lacking. We here concentrate on immune memory that is induced by pathogenic challenges, but also extent our view to a non-pathogenic context, i.e. allograft rejection, which can also show forms of memory and can inform us about general principles of specific self-nonself recognition. We discuss definitions of immune memory and a number of relevant aspects such as the type of antigens used, the route of exposure, and the kinetics of reactions following priming.
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Affiliation(s)
- Barbara Milutinović
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria.
| | - Joachim Kurtz
- Institute for Evolution and Biodiversity, University of Münster, Hüfferstrasse 1, 48149 Münster, Germany.
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18
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Huang S, Tao X, Yuan S, Zhang Y, Li P, Beilinson HA, Zhang Y, Yu W, Pontarotti P, Escriva H, Le Petillon Y, Liu X, Chen S, Schatz DG, Xu A. Discovery of an Active RAG Transposon Illuminates the Origins of V(D)J Recombination. Cell 2016; 166:102-14. [PMID: 27293192 DOI: 10.1016/j.cell.2016.05.032] [Citation(s) in RCA: 129] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 03/18/2016] [Accepted: 05/06/2016] [Indexed: 01/08/2023]
Abstract
Co-option of RAG1 and RAG2 for antigen receptor gene assembly by V(D)J recombination was a crucial event in the evolution of jawed vertebrate adaptive immunity. RAG1/2 are proposed to have arisen from a transposable element, but definitive evidence for this is lacking. Here, we report the discovery of ProtoRAG, a DNA transposon family from lancelets, the most basal extant chordates. A typical ProtoRAG is flanked by 5-bp target site duplications and a pair of terminal inverted repeats (TIRs) resembling V(D)J recombination signal sequences. Between the TIRs reside tail-to-tail-oriented, intron-containing RAG1-like and RAG2-like genes. We demonstrate that ProtoRAG was recently active in the lancelet germline and that the lancelet RAG1/2-like proteins can mediate TIR-dependent transposon excision, host DNA recombination, transposition, and low-efficiency TIR rejoining using reaction mechanisms similar to those used by vertebrate RAGs. We propose that ProtoRAG represents a molecular "living fossil" of the long-sought RAG transposon.
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Affiliation(s)
- Shengfeng Huang
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Xin Tao
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Shaochun Yuan
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Yuhang Zhang
- Department of Immunobiology, Yale School of Medicine, New Haven, CT 06510, USA
| | - Peiyi Li
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Helen A Beilinson
- Department of Immunobiology, Yale School of Medicine, New Haven, CT 06510, USA
| | - Ya Zhang
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Wenjuan Yu
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Pierre Pontarotti
- CNRS, Centrale Marseille, I2M UMR 7373, Equipe Evolution Biologique et Modélisation, Aix-Marseille Université, 13284 Marseille, France
| | - Hector Escriva
- CNRS, UMR 7232, Biologie Integrative des Organismes Marins (BIOM), Observatoire Océanologique de Banyuls-sur-Mer, Banyuls-sur-Mer, Université Pierre et Marie Curie, Université Paris 6, 75005 Paris, France
| | - Yann Le Petillon
- CNRS, UMR 7232, Biologie Integrative des Organismes Marins (BIOM), Observatoire Océanologique de Banyuls-sur-Mer, Banyuls-sur-Mer, Université Pierre et Marie Curie, Université Paris 6, 75005 Paris, France
| | - Xiaolong Liu
- State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, People's Republic of China
| | - Shangwu Chen
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - David G Schatz
- Department of Immunobiology, Yale School of Medicine, New Haven, CT 06510, USA; Howard Hughes Medical Institute, 295 Congress Avenue, New Haven, CT 06511, USA
| | - Anlong Xu
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China; Beijing University of Chinese Medicine, Dong San Huan Road, Chao-yang District, Beijing 100029, People's Republic of China.
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19
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Carmona LM, Fugmann SD, Schatz DG. Collaboration of RAG2 with RAG1-like proteins during the evolution of V(D)J recombination. Genes Dev 2016; 30:909-17. [PMID: 27056670 PMCID: PMC4840297 DOI: 10.1101/gad.278432.116] [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: 01/26/2016] [Accepted: 03/09/2016] [Indexed: 12/03/2022]
Abstract
Here, Carmona et al. show that two ancestral RAG1 proteins, Transib transposase and purple sea urchin RAG1-like, have a latent ability to initiate V(D)J recombination when coexpressed with RAG2 and that in vitro transposition by Transib transposase is stimulated by RAG2. They propose that evolution of RAG1/RAG2 began with a Transib transposon whose intrinsic recombination activity was enhanced by capture of an ancestral RAG2, allowing for the development of adaptive immunity. The recombination-activating gene 1 (RAG1) and RAG2 proteins initiate V(D)J recombination, the process that assembles the B- and T-lymphocyte antigen receptor genes of jawed vertebrates. RAG1 and RAG2 are thought to have arisen from a transposable element, but the origins of this element are not understood. We show that two ancestral RAG1 proteins, Transib transposase and purple sea urchin RAG1-like, have a latent ability to initiate V(D)J recombination when coexpressed with RAG2 and that in vitro transposition by Transib transposase is stimulated by RAG2. Conversely, we report low levels of V(D)J recombination by RAG1 in the absence of RAG2. Recombination by RAG1 alone differs from canonical V(D)J recombination in having lost the requirement for asymmetric DNA substrates, implicating RAG2 in the origins of the “12/23 rule,” a fundamental regulatory feature of the reaction. We propose that evolution of RAG1/RAG2 began with a Transib transposon whose intrinsic recombination activity was enhanced by capture of an ancestral RAG2, allowing for the development of adaptive immunity.
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Affiliation(s)
- Lina Marcela Carmona
- Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut, 06520, USA
| | - Sebastian D Fugmann
- Department of Biomedical Sciences, Chang Gung University, Tao-Yuan City 33302, Taiwan; Chang Gung Immunology Consortium, Chang Gung Memorial Hospital, Chang Gung University, Tao-Yuan City 33302, Taiwan
| | - David G Schatz
- Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut, 06520, USA; Howard Hughes Medical Institute, New Haven, Connecticut 06511, USA
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20
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Zhu LY, Shao T, Nie L, Zhu LY, Xiang LX, Shao JZ. Evolutionary implication of B-1 lineage cells from innate to adaptive immunity. Mol Immunol 2015; 69:123-30. [PMID: 26573260 DOI: 10.1016/j.molimm.2015.10.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 10/20/2015] [Accepted: 10/20/2015] [Indexed: 11/27/2022]
Abstract
The paradigm that B cells mainly play a central role in adaptive immunity may have to be reevaluated because B-1 lineage cells have been found to exhibit innate-like functions, such as phagocytic and bactericidal activities. Therefore, the evolutionary connection of B-1 lineage cells between innate and adaptive immunities have received much attention. In this review, we summarized various innate-like characteristics of B-1 lineage cells, such as natural antibody production, antigen-presenting function in primary adaptive immunity, and T cell-independent immune responses. These characteristics seem highly conserved between fish B cells and mammalian B-1 cells during vertebrate evolution. We proposed an evolutionary outline of B cells by comparing biological features, including morphology, phenotype, ontogeny, and functional activity between B-1 lineage cells and macrophages or B-2 cells. The B-1 lineage may be a transitional cell type between phagocytic cells (e.g., macrophages) and B-2 cells that functionally connects innate and adaptive immunities. Our discussion would contribute to the understanding on the origination of B cells specialized in adaptive immunity from innate immunity. The results might provide further insight into the evolution of the immune system as a whole.
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Affiliation(s)
- Lv-yun Zhu
- College of Science, National University of Defense Technology, Changsha, Hunan 410073, People's Republic of China; College of Life Sciences, Zhejiang University, Hangzhou 310058, People's Republic of China; Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Hangzhou 310058, People's Republic of China
| | - Tong Shao
- College of Life Sciences, Zhejiang University, Hangzhou 310058, People's Republic of China; Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Hangzhou 310058, People's Republic of China
| | - Li Nie
- College of Life Sciences, Zhejiang University, Hangzhou 310058, People's Republic of China; Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Hangzhou 310058, People's Republic of China
| | - Ling-yun Zhu
- College of Science, National University of Defense Technology, Changsha, Hunan 410073, People's Republic of China
| | - Li-xin Xiang
- College of Life Sciences, Zhejiang University, Hangzhou 310058, People's Republic of China; Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Hangzhou 310058, People's Republic of China.
| | - Jian-zhong Shao
- College of Life Sciences, Zhejiang University, Hangzhou 310058, People's Republic of China; Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Hangzhou 310058, People's Republic of China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, People's Republic of China.
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21
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van Niekerk G, Davis T, Engelbrecht AM. Was the evolutionary road towards adaptive immunity paved with endothelium? Biol Direct 2015; 10:47. [PMID: 26341882 PMCID: PMC4560925 DOI: 10.1186/s13062-015-0079-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 09/02/2015] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND The characterization of a completely novel adaptive immune system (AIS) in jawless vertebrates (hagfish and lampreys) presents an excellent opportunity for exploring similarities and differences in design principles. It also highlights a somewhat neglected question: Why did vertebrates, representing only 5 % of all animals, evolve a system as complex as an AIS twice, whereas invertebrates failed to do so? A number of theories have been presented in answer to this question. However, these theories either fail to explain why invertebrates would not similarly develop an AIS and are confounded by issues of causality, or have been challenged by more recent findings. PRESENTATION OF THE HYPOTHESIS Instead of identifying a selective pressure that would drive the development of an AIS, we hypothesise that invertebrates failed to develop an AIS because of the evolutionary constraints imposed by these animals' physiological context. In particular, we argue that a number of vascular innovations in vertebrates allowed the effective implementation of an AIS. A lower blood volume allowed for a higher antibody titer (i.e., less 'diluted' antibody concentration), rendering these immune effectors more cost-effective. In addition, both a high circulatory velocity and the ability of endothelium to coordinate immune cell trafficking promote 'epitope sampling'. Collectively, these innovations allowed the effective implementation of AIS in vertebrates. TESTING THE HYPOTHESIS The hypothesis posits that a number of innovations to the vascular system provided the release from constraints which allowed the implementation of an AIS. However, this hypothesis would be refuted by phylogenetic analysis demonstrating that the AIS preceded these vascular innovations. The hypothesis also suggests that vascular performance would have an impact on the efficacy of an AIS, thus predicting a correlation between the vascular parameters of a species and its relative investment in AIS. The contribution of certain vascular innovations in augmenting immune functionality of an AIS can be tested by modelling the effect of different vascular parameters on AIS efficacy. IMPLICATIONS OF THE HYPOTHESIS The hypothesis not only explains the immunological dimorphism between vertebrates and invertebrates but also brings to attention the fact that immunity is dependent on more than just an immune system.
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Affiliation(s)
- Gustav van Niekerk
- Department of Physiological Sciences, Stellenbosch University, Private Bag X1, Matieland, Stellenbosch, 7600, South Africa.
| | - Tanja Davis
- Department of Physiological Sciences, Stellenbosch University, Private Bag X1, Matieland, Stellenbosch, 7600, South Africa.
| | - Anna-Mart Engelbrecht
- Department of Physiological Sciences, Stellenbosch University, Private Bag X1, Matieland, Stellenbosch, 7600, South Africa.
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Abstract
The modular, noncontiguous architecture of the antigen receptor genes necessitates their assembly through V(D)J recombination. This program of DNA breakage and rejoining occurs during early lymphocyte development, and depends on the RAG1 and RAG2 proteins, whose collaborative endonuclease activity targets specific DNA motifs enriched in the antigen receptor loci. This essential gene shuffling reaction requires lymphocytes to traverse several developmental stages wherein DNA breakage is tolerated, while minimizing the expense to overall genome integrity. Thus, RAG activity is subject to stringent temporal and spatial regulation. The RAG proteins themselves also contribute autoregulatory properties that coordinate their DNA cleavage activity with target chromatin structure, cell cycle status, and DNA repair pathways. Even so, lapses in regulatory restriction of RAG activity are apparent in the aberrant V(D)J recombination events that underlie many lymphomas. In this review, we discuss the current understanding of the RAG endonuclease, its widespread binding in the lymphocyte genome, its noncleavage activities that restrain its enzymatic potential, and the growing evidence of its evolution from an ancient transposase.
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Kumar A, Bhandari A, Sarde SJ, Muppavarapu S, Tandon R. Understanding V(D)J recombination initiator RAG1 gene using molecular phylogenetic and genetic variant analyses and upgrading missense and non-coding variants of clinical importance. Biochem Biophys Res Commun 2015; 462:301-13. [DOI: 10.1016/j.bbrc.2015.04.125] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 04/26/2015] [Indexed: 11/27/2022]
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van Niekerk G, Engelbrecht AM. Commentary on: "A common origin for immunity and digestion". Front Microbiol 2015; 6:531. [PMID: 26074909 PMCID: PMC4445048 DOI: 10.3389/fmicb.2015.00531] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 05/14/2015] [Indexed: 01/09/2023] Open
Affiliation(s)
- Gustav van Niekerk
- Department of Physiological Sciences, Stellenbosch University Stellenbosch, South Africa
| | - Anna-Mart Engelbrecht
- Department of Physiological Sciences, Stellenbosch University Stellenbosch, South Africa
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van Niekerk G, Engelbrecht AM. On the evolutionary origin of the adaptive immune system—The adipocyte hypothesis. Immunol Lett 2015; 164:81-7. [DOI: 10.1016/j.imlet.2015.02.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 02/03/2015] [Accepted: 02/09/2015] [Indexed: 12/18/2022]
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Sinkovics JG. The cell survival pathways of the primordial RNA-DNA complex remain conserved in the extant genomes and may function as proto-oncogenes. Eur J Microbiol Immunol (Bp) 2015; 5:25-43. [PMID: 25883792 PMCID: PMC4397846 DOI: 10.1556/eujmi-d-14-00034] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 12/22/2014] [Indexed: 01/09/2023] Open
Abstract
Malignantly transformed (cancer) cells of multicellular hosts, including human cells, operate activated biochemical pathways that recognizably derived from unicellular ancestors. The descendant heat shock proteins of thermophile archaea now chaperon oncoproteins. The ABC cassettes of toxin-producer zooxantella Symbiodinia algae pump out the cytoplasmic toxin molecules; malignantly transformed cells utilize the derivatives of these cassettes to get rid of chemotherapeuticals. High mobility group helix-loop-helix proteins, protein arginine methyltransferases, proliferating cell nuclear antigens, and Ki-67 nuclear proteins, that protect and repair DNA in unicellular life forms, support oncogenes in transformed cells. The cell survival pathways of Wnt-β-catenin, Hedgehog, PI3K, MAPK-ERK, STAT, Ets, JAK, Pak, Myb, achaete scute, circadian rhythms, Bruton kinase and others, which are physiological in uni- and early multicellular eukaryotic life forms, are constitutively encoded in complex oncogenic pathways in selected single cells of advanced multicellular eukaryotic hosts. Oncogenes and oncoproteins in advanced multicellular hosts recreate selected independently living and immortalized unicellular life forms, which are similar to extinct and extant protists. These unicellular life forms are recognized at the clinics as autologous "cancer cells".
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Affiliation(s)
- J G Sinkovics
- St. Joseph's Hospital Cancer Institute Affiliated with the H. L. Moffitt Comprehensive Cancer Center, Morsani College of Medicine, Department of Molecular Medicine, The University of South Florida Tampa, FL USA
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Yuan S, Ruan J, Huang S, Chen S, Xu A. Amphioxus as a model for investigating evolution of the vertebrate immune system. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2015; 48:297-305. [PMID: 24877655 DOI: 10.1016/j.dci.2014.05.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 05/09/2014] [Accepted: 05/12/2014] [Indexed: 06/03/2023]
Abstract
As the most basal chordate, the cephalochordate amphioxus has unique features that make it a valuable model for understanding the phylogeny of immunity. Vertebrate adaptive immunity (VAI) mediated by lymphocytes bearing variable receptors has been well-studied in mammals but not observed in invertebrates. However, the identification of lymphocyte-like cells in the gill along with genes related with lymphoid proliferation and differentiation indicates the presence of some basic components of VAI in amphioxus. Without VAI, amphioxus utilizes about 10% of its gene repertoires, and an ongoing domain reshuffling mechanism among these genes, for innate immunity, suggesting extraordinary innate complexity and diversity not observed in other species. Innate diversity may not be comparable to the somatic diversity of the VAI, but there is no doubt of the success of this immune system, since amphioxus has existed for over 500 million years. Studies of amphioxus immunity may provide information on the reduction of innate immune complexity and the conflict between microbiota and host shaped the evolution of adaptive immune systems (AIS) during chordate evolution.
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Affiliation(s)
- Shaochun Yuan
- State Key Laboratory of Biocontrol, Department of Biochemistry, College of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Jie Ruan
- State Key Laboratory of Biocontrol, Department of Biochemistry, College of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Shengfeng Huang
- State Key Laboratory of Biocontrol, Department of Biochemistry, College of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Shangwu Chen
- State Key Laboratory of Biocontrol, Department of Biochemistry, College of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Anlong Xu
- State Key Laboratory of Biocontrol, Department of Biochemistry, College of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China; Beijing University of Chinese Medicine, Beijing 100029, People's Republic of China.
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RAG1-mediated ubiquitylation of histone H3 is required for chromosomal V(D)J recombination. Cell Res 2015; 25:181-92. [PMID: 25572281 DOI: 10.1038/cr.2015.1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Revised: 08/26/2014] [Accepted: 10/21/2014] [Indexed: 12/22/2022] Open
Abstract
RAG1 and RAG2 proteins are key components in V(D)J recombination. The core region of RAG1 is capable of catalyzing the recombination reaction; however, the biological function of non-core RAG1 remains largely unknown. Here, we show that in a murine-model carrying the RAG1 ring-finger conserved cysteine residue mutation (C325Y), V(D)J recombination was abrogated at the cleavage step, and this effect was accompanied by decreased mono-ubiquitylation of histone H3. Further analyses suggest that un-ubiquitylated histone H3 restrains RAG1 to the chromatin by interacting with the N-terminal 218 amino acids of RAG1. Our data provide evidence for a model in which ubiquitylation of histone H3 mediated by the ring-finger domain of RAG1 triggers the release of RAG1, thus allowing its transition into the cleavage phase. Collectively, our findings reveal that the non-core region of RAG1 facilitates chromosomal V(D)J recombination in a ubiquitylation-dependent pathway.
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Huang S, Chen Z, Yan X, Yu T, Huang G, Yan Q, Pontarotti PA, Zhao H, Li J, Yang P, Wang R, Li R, Tao X, Deng T, Wang Y, Li G, Zhang Q, Zhou S, You L, Yuan S, Fu Y, Wu F, Dong M, Chen S, Xu A. Decelerated genome evolution in modern vertebrates revealed by analysis of multiple lancelet genomes. Nat Commun 2014; 5:5896. [PMID: 25523484 PMCID: PMC4284660 DOI: 10.1038/ncomms6896] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 11/18/2014] [Indexed: 01/19/2023] Open
Abstract
Vertebrates diverged from other chordates ~500 Myr ago and experienced successful innovations and adaptations, but the genomic basis underlying vertebrate origins are not fully understood. Here we suggest, through comparison with multiple lancelet (amphioxus) genomes, that ancient vertebrates experienced high rates of protein evolution, genome rearrangement and domain shuffling and that these rates greatly slowed down after the divergence of jawed and jawless vertebrates. Compared with lancelets, modern vertebrates retain, at least relatively, less protein diversity, fewer nucleotide polymorphisms, domain combinations and conserved non-coding elements (CNE). Modern vertebrates also lost substantial transposable element (TE) diversity, whereas lancelets preserve high TE diversity that includes even the long-sought RAG transposon. Lancelets also exhibit rapid gene turnover, pervasive transcription, fastest exon shuffling in metazoans and substantial TE methylation not observed in other invertebrates. These new lancelet genome sequences provide new insights into the chordate ancestral state and the vertebrate evolution. The lancelet, or amphioxus, is an extant basal chordate that diverged from other chordate lineages about 550 million years ago. Here the authors sequence and assemble the diploid genome of a male adult of the Chinese lancelet, B. belcheri, and highlight genomic features that may have played an important role in the origin and evolution of vertebrates.
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Affiliation(s)
- Shengfeng Huang
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Zelin Chen
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Xinyu Yan
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Ting Yu
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Guangrui Huang
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Qingyu Yan
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Pierre Antoine Pontarotti
- Evolution Biologique et Modélisation UMR 7353 Aix Marseille Université/CNRS, 3 Place Victor Hugo, 13331 Marseille, France
| | - Hongchen Zhao
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Jie Li
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Ping Yang
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Ruihua Wang
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Rui Li
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Xin Tao
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Ting Deng
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Yiquan Wang
- 1] School of Life Sciences, Xiamen University, Xiamen 361005, China [2] Shenzhen Research Institute of Xiamen University, Shenzhen 518058, China
| | - Guang Li
- 1] School of Life Sciences, Xiamen University, Xiamen 361005, China [2] Shenzhen Research Institute of Xiamen University, Shenzhen 518058, China
| | - Qiujin Zhang
- Fujian Key Laboratory of Developmental and Neuron Biology, College of Life Sciences, Fujian Normal University, Fuzhou 350108, China
| | - Sisi Zhou
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Leiming You
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Shaochun Yuan
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Yonggui Fu
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Fenfang Wu
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Meiling Dong
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Shangwu Chen
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Anlong Xu
- 1] State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China [2] Beijing University of Chinese Medicine, Dong San Huang Road, Chao-yang District, Beijing 100029, China
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Buchmann K. Evolution of Innate Immunity: Clues from Invertebrates via Fish to Mammals. Front Immunol 2014; 5:459. [PMID: 25295041 PMCID: PMC4172062 DOI: 10.3389/fimmu.2014.00459] [Citation(s) in RCA: 326] [Impact Index Per Article: 32.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 09/08/2014] [Indexed: 11/13/2022] Open
Abstract
Host responses against invading pathogens are basic physiological reactions of all living organisms. Since the appearance of the first eukaryotic cells, a series of defense mechanisms have evolved in order to secure cellular integrity, homeostasis, and survival of the host. Invertebrates, ranging from protozoans to metazoans, possess cellular receptors, which bind to foreign elements and differentiate self from non-self. This ability is in multicellular animals associated with presence of phagocytes, bearing different names (amebocytes, hemocytes, coelomocytes) in various groups including animal sponges, worms, cnidarians, mollusks, crustaceans, chelicerates, insects, and echinoderms (sea stars and urchins). Basically, these cells have a macrophage-like appearance and function and the repair and/or fight functions associated with these cells are prominent even at the earliest evolutionary stage. The cells possess pathogen recognition receptors recognizing pathogen-associated molecular patterns, which are well-conserved molecular structures expressed by various pathogens (virus, bacteria, fungi, protozoans, helminths). Scavenger receptors, Toll-like receptors, and Nod-like receptors (NLRs) are prominent representatives within this group of host receptors. Following receptor-ligand binding, signal transduction initiates a complex cascade of cellular reactions, which lead to production of one or more of a wide array of effector molecules. Cytokines take part in this orchestration of responses even in lower invertebrates, which eventually may result in elimination or inactivation of the intruder. Important innate effector molecules are oxygen and nitrogen species, antimicrobial peptides, lectins, fibrinogen-related peptides, leucine rich repeats (LRRs), pentraxins, and complement-related proteins. Echinoderms represent the most developed invertebrates and the bridge leading to the primitive chordates, cephalochordates, and urochordates, in which many autologous genes and functions from their ancestors can be found. They exhibit numerous variants of innate recognition and effector molecules, which allow fast and innate responses toward diverse pathogens despite lack of adaptive responses. The primitive vertebrates (agnathans also termed jawless fish) were the first to supplement innate responses with adaptive elements. Thus hagfish and lampreys use LRRs as variable lymphocyte receptors, whereas higher vertebrates [cartilaginous and bony fishes (jawed fish), amphibians, reptiles, birds, and mammals] developed the major histocompatibility complex, T-cell receptors, and B-cell receptors (immunoglobulins) as additional adaptive weaponry to assist innate responses. Extensive cytokine networks are recognized in fish, but related signal molecules can be traced among invertebrates. The high specificity, antibody maturation, immunological memory, and secondary responses of adaptive immunity were so successful that it allowed higher vertebrates to reduce the number of variants of the innate molecules originating from both invertebrates and lower vertebrates. Nonetheless, vertebrates combine the two arms in an intricate inter-dependent network. Organisms at all developmental stages have, in order to survive, applied available genes and functions of which some may have been lost or may have changed function through evolution. The molecular mechanisms involved in evolution of immune molecules, might apart from simple base substitutions be as diverse as gene duplication, deletions, alternative splicing, gene recombination, domain shuffling, retrotransposition, and gene conversion. Further, variable regulation of gene expression may have played a role.
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Affiliation(s)
- Kurt Buchmann
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
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