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Zhang L, Li L, Zhang G. A Crassostrea gigas Toll-like receptor and comparative analysis of TLR pathway in invertebrates. FISH & SHELLFISH IMMUNOLOGY 2011; 30:653-660. [PMID: 21195773 DOI: 10.1016/j.fsi.2010.12.023] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2010] [Revised: 12/12/2010] [Accepted: 12/24/2010] [Indexed: 05/30/2023]
Abstract
Toll-like receptor (TLR) signaling pathway was an important and evolutionarily conserved innate immune pathway. Evolutionary lineage of this pathway in the Lophotrochozoans is still less understood. In this study, we cloned a novel TLR, a key component of TLR pathway, from Crassostrea gigas, and named it CgToll-1. The 4343 base pairs full-length cDNA was assembled with the 3' and 5' RACE (rapid amplification of cDNA ends) PCR results, and containing a 3540 bp open reading frame, which encoding a putative TLR protein of 1179 amino acid residues. Real-time reverse transcription polymerase chain reaction analysis revealed that the highest CgToll-1 expression level was in hemolymph, and the expression pattern in hemolymph dramatically increased in the presence of bacteria Vibrio anguillarum. Furthermore, TLR pathway core genes of mollusks were searched and compared with model invertebrates. Phylogenetic trees of two downstream genes (IκB, Rel) showed that mollusks genes were closer to Drosophila melanogaster than Strongylocentrotus purpuratus, while three upstream genes (MyD88, IRAK, TRAF6) showed the opposite propensity. We have also detected that these two downstream genes were significantly more conservative than the three upstream genes based on amino acid sequence alignment. We found no significant difference between the codon usage biases of TLR pathway genes. This study suggests that CgToll-1 was a constitutive and inducible protein and thus could play an important role in the immune responses against bacterium infection. Besides, comparative analysis of TLR pathway showed that gene loss and divergence might exist during evolution in invertebrate.
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Affiliation(s)
- Linlin Zhang
- Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Rd, Qingdao 266071, China.
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52
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Lange C, Hemmrich G, Klostermeier UC, López-Quintero JA, Miller DJ, Rahn T, Weiss Y, Bosch TCG, Rosenstiel P. Defining the origins of the NOD-like receptor system at the base of animal evolution. Mol Biol Evol 2010; 28:1687-702. [PMID: 21183612 DOI: 10.1093/molbev/msq349] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Distinguishing self from nonself and the onset of defense effector mechanisms upon recognition of pathogens are essential for the survival of all life forms in the animal kingdom. The family of nucleotide -binding and oligomeriszation domain-like receptors (NLRs) was first identified in vertebrates and comprises a group of pivotal sensor protein of the innate immune system for microbial cell wall components or danger signals. Here, we provide first evidence that early diverging metazoans have large and complex NLR repertoires. The cnidarian NACHT/NB-ARC genes include novel combinations of domains, and the number of one specific type (NB-ARC and tetratricopeptide repeat containing) in Hydra is particularly large. We characterize the transcript structure and expression patterns of a selected HyNLR, HyNLR type 1 and describe putative interaction partners. In a heterologous expression system, we show induced proximity recruitment of an effector caspase (HyDD-Caspase) to the HyNLR type 1 protein upon oligomerization indicating a potential role of caspase activation downstream of NLR activation in Hydra. These results add substantially to our understanding of the ancestral innate immune repertoire as well as providing the first insights into putative cytoplasmic defense mechanisms at the base of animal evolution.
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Affiliation(s)
- Christina Lange
- Zoological Institute, Christian-Albrechts-University Kiel, Kiel, Germany
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53
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Evolution of host innate defence: insights from Caenorhabditis elegans and primitive invertebrates. Nat Rev Immunol 2010; 10:47-58. [PMID: 20029447 DOI: 10.1038/nri2689] [Citation(s) in RCA: 301] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The genetically tractable model organism Caenorhabditis elegans was first used to model bacterial virulence in vivo a decade ago. Since then, great strides have been made in identifying the host response pathways that are involved in its defence against infection. Strikingly, C. elegans seems to detect, and respond to, infection without the involvement of its homologue of Toll-like receptors, in contrast to the well-established role for these proteins in innate immunity in mammals. What, therefore, do we know about host defence mechanisms in C. elegans and what can they tell us about innate immunity in higher organisms?
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Messier-Solek C, Buckley KM, Rast JP. Highly diversified innate receptor systems and new forms of animal immunity. Semin Immunol 2009; 22:39-47. [PMID: 20022762 DOI: 10.1016/j.smim.2009.11.007] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2009] [Accepted: 11/18/2009] [Indexed: 12/20/2022]
Abstract
Detailed understanding of animal immunity derives almost entirely from investigations of vertebrates, with a smaller, but significant, contribution from studies in fruit flies. This limited phylogenetic scope has artificially polarized the larger view of animal immunity toward the complex adaptive immune systems of vertebrates on the one hand and systems driven by relatively small, stable families of innate receptors of insects on the other. In the past few years analyses of a series of invertebrate deuterostome genome sequences, including those from echinoderms and cephalochordates, sharply modify this view. These findings have far-reaching implications for characterizing the potential range of animal immunity and for inferring the evolutionary pathway that led to vertebrate immune systems.
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Affiliation(s)
- Cynthia Messier-Solek
- Department of Medical Biophysics, University of Toronto, Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Rm. S126B, Toronto, ON M4N 3M5, Canada.
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55
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Villarreal LP. The source of self: genetic parasites and the origin of adaptive immunity. Ann N Y Acad Sci 2009; 1178:194-232. [PMID: 19845639 DOI: 10.1111/j.1749-6632.2009.05020.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Stable colonization of the host by viruses (genetic parasites) can alter the systems of host identity and provide immunity against related viruses. To attain the needed stability, some viruses of prokaryotes (P1 phage) use a strategy called an addiction module. The linked protective and destructive gene functions of an addiction module insures both virus persistence but will also destroy cells that interrupt this module and thereby prevent infection by competitors. Previously, I have generalized this concept to also include persistent and lytic states of virus infection, which can be considered as a virus addiction module. Such states often involve defective viruses. In this report, I examine the origin of the adaptive immune system from the perspective of a virus addiction module. The likely role of both endogenous and exogenous retroviruses, DNA viruses, and their defective elements is considered in the origin of all the basal components of adaptive immunity (T-cell receptor, RAG-mediated gene rearrangement, clonal lymphocyte proliferation, antigen surface presentation, apoptosis, and education of immune cells). It is concluded that colonization by viruses and their defectives provides a more coherent explanation for the origin of adaptive immunity.
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Affiliation(s)
- Luis P Villarreal
- Center for Virus Research, Department of Molecular Biology and Biochemistry, University of California, Irvine, California 92697, USA.
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56
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Augustin R, Fraune S, Bosch TCG. How Hydra senses and destroys microbes. Semin Immunol 2009; 22:54-8. [PMID: 20005124 DOI: 10.1016/j.smim.2009.11.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2009] [Accepted: 11/11/2009] [Indexed: 02/07/2023]
Abstract
Molecular genetic evidence has revealed that the basic templates of innate immune sensors were laid down in ancient animals such as the cnidarian Hydra. Important functions of Hydra's innate immune sensors and effectors include not only protection against pathogens but also controlling tissue-microbiota homeostasis. The deep evolutionary connections imply that invertebrate and mammalian immune pathways have evolved from a reduced number of common ancestral building blocks to their present configurations.
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Affiliation(s)
- René Augustin
- Zoological Institute, Christian-Albrechts-University Kiel, Olshausenstrasse 40, 24098 Kiel, Germany
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57
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Activity of the novel peptide arminin against multiresistant human pathogens shows the considerable potential of phylogenetically ancient organisms as drug sources. Antimicrob Agents Chemother 2009; 53:5245-50. [PMID: 19770277 DOI: 10.1128/aac.00826-09] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The emergence of multidrug-resistant bacteria highlights the need for new antibacterial agents. Arminin 1a is a novel antimicrobial peptide discovered during investigations of the epithelial defense of the ancient metazoan Hydra. Following proteolytic processing, the 31-amino-acid-long positively charged C-terminal part of arminin 1a exhibits potent and broad-spectrum activity against bacteria, including multiresistant human pathogenic strains, such as methicillin-resistant Staphylococcus aureus (MRSA) strains (minimal bactericidal concentration, 0.4 microM to 0.8 microM). Ultrastructural observations indicate that bacteria are killed by disruption of the bacterial cell wall. Remarkably, the antibacterial activity of arminin 1a is not affected under the physiological salt conditions of human blood. In addition, arminin 1a is a selective antibacterial agent that does not affect human erythrocyte membranes. Arminin 1a shows no sequence homology to any known antimicrobial peptide. Because of its high level of activity against multiresistant bacterial strains pathogenic for humans, the peptide arminin 1a is a promising template for a new class of antibiotics. Our data suggest that ancient metazoan organisms such as Hydra hold promise for the detection of novel antimicrobial molecules and the treatment of infections caused by multiresistant bacteria.
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58
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Wölfle U, Martin S, Emde M, Schempp C. Dermatology in the Darwin anniversary. Part 2: Evolution of the skin-associated immune system. J Dtsch Dermatol Ges 2009; 7:862-9. [PMID: 19725839 DOI: 10.1111/j.1610-0387.2009.07202.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The present review highlights the evolution of the skin-associated immune system from the invertebrates to the vertebrates and man. In the invertebrates a non-specific humoral immune response dominates. It includes antimicrobial peptides, oxidases, lysozyme, agglutinins, coagulins and melanin. The cellular immune system initially consists of undifferentiated mesenchymal stem cells. Later migrating phagocytes and natural killer cells occur. From the fishes on, dendritic cells are present, linking innate and adaptive immune responses. In addition to this unspecific but highly effective immune system, the specific immune response, based on genetic recombination, is present in the vertebrates starting with the chondral fishes. The adaptive immune system possesses unlimited numbers of highly specific antibodies and T-cell receptors, increasingly tissue specific MHC restriction, and cellular memory. Elements of the skin-associated adaptive immune system are first detectable in the teleost fishes in the form of intraepithelial IgM positive lymphocytes and dendritic cells. Moving up to mammals and man, the skin-associated immune system became more and more complex and effective.
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Affiliation(s)
- Ute Wölfle
- Competence Center skintegral, Department of Dermatology, University Medical Center Freiburg, Germany
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59
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Bosch TCG, Augustin R, Anton-Erxleben F, Fraune S, Hemmrich G, Zill H, Rosenstiel P, Jacobs G, Schreiber S, Leippe M, Stanisak M, Grötzinger J, Jung S, Podschun R, Bartels J, Harder J, Schröder JM. Uncovering the evolutionary history of innate immunity: the simple metazoan Hydra uses epithelial cells for host defence. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2009; 33:559-569. [PMID: 19013190 DOI: 10.1016/j.dci.2008.10.004] [Citation(s) in RCA: 151] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2008] [Revised: 10/10/2008] [Accepted: 10/13/2008] [Indexed: 05/27/2023]
Abstract
Although many properties of the innate immune system are shared among multicellular animals, the evolutionary origin remains poorly understood. Here we characterize the innate immune system in Hydra, one of the simplest multicellular animals known. In the complete absence of both protective mechanical barriers and mobile phagocytes, Hydra's epithelium is remarkably well equipped with potent antimicrobial peptides to prevent pathogen infection. Induction of antimicrobial peptide production is mediated by the interaction of a leucine-rich repeats (LRRs) domain containing protein with a TIR-domain containing protein lacking LRRs. Conventional Toll-like receptors (TLRs) are absent in the Hydra genome. Our findings support the hypothesis that the epithelium represents the ancient system of host defence.
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Affiliation(s)
- Thomas C G Bosch
- Zoological Institute, Christian-Albrechts-University Kiel, Germany.
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60
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de Jong D, Eitel M, Jakob W, Osigus HJ, Hadrys H, Desalle R, Schierwater B. Multiple dicer genes in the early-diverging metazoa. Mol Biol Evol 2009; 26:1333-40. [PMID: 19276153 DOI: 10.1093/molbev/msp042] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Dicer proteins are highly conserved, are present in organisms ranging from plants to metazoans, and are essential components of the RNA interference pathway. Although the complement of Dicer proteins has been investigated in many "higher" metazoans, there has been no corresponding characterization of Dicer proteins in any early-branching metazoan. We cloned partial cDNAs of genes belonging to the Dicer family from the anthozoan cnidarian Nematostella vectensis and two distantly related haplotypes (species lineages) of the Placozoa (Trichoplax adhaerens 16S haplotype 1 [H1] and Placozoa sp. [H2]). We also identified Dicer genes in the hydrozoan Hydra magnipapillata and the demosponge Amphimedon queenslandica with the use of publicly available sequence databases. Two Dicer genes are present in each cnidarian species, whereas five Dicer genes each are found in the Porifera and Placozoa. Phylogenetic analyses comparing these and other metazoan Dicers suggest an ancient duplication event of a "Proto-Dicer" gene. We show that the Placozoa is the only known metazoan phylum which contains both representatives of this duplication event and that the multiple Dicer genes of the "basal" metazoan phyla represent lineage-specific duplications. There is a striking diversity of Dicer genes in basal metazoans, in stark contrast to the single Dicer gene found in most higher metazoans. This new data has allowed us to formulate new hypotheses regarding the evolution of metazoan Dicer proteins and their possible functions in the early diverging metazoan phyla. We theorize that the multiple placozoan Dicer genes fulfill a specific biological requirement, such as an immune defense strategy against viruses.
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Affiliation(s)
- Danielle de Jong
- Tieraerztliche Hochschule, Division of Ecology and Evolution, Hannover, Germany
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61
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Zhu B, Pennack JA, McQuilton P, Forero MG, Mizuguchi K, Sutcliffe B, Gu CJ, Fenton JC, Hidalgo A. Drosophila neurotrophins reveal a common mechanism for nervous system formation. PLoS Biol 2009; 6:e284. [PMID: 19018662 PMCID: PMC2586362 DOI: 10.1371/journal.pbio.0060284] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2008] [Accepted: 10/08/2008] [Indexed: 01/05/2023] Open
Abstract
Neurotrophic interactions occur in Drosophila, but to date, no neurotrophic factor had been found. Neurotrophins are the main vertebrate secreted signalling molecules that link nervous system structure and function: they regulate neuronal survival, targeting, synaptic plasticity, memory and cognition. We have identified a neurotrophic factor in flies, Drosophila Neurotrophin (DNT1), structurally related to all known neurotrophins and highly conserved in insects. By investigating with genetics the consequences of removing DNT1 or adding it in excess, we show that DNT1 maintains neuronal survival, as more neurons die in DNT1 mutants and expression of DNT1 rescues naturally occurring cell death, and it enables targeting by motor neurons. We show that Spätzle and a further fly neurotrophin superfamily member, DNT2, also have neurotrophic functions in flies. Our findings imply that most likely a neurotrophin was present in the common ancestor of all bilateral organisms, giving rise to invertebrate and vertebrate neurotrophins through gene or whole-genome duplications. This work provides a missing link between aspects of neuronal function in flies and vertebrates, and it opens the opportunity to use Drosophila to investigate further aspects of neurotrophin function and to model related diseases. Neurotrophins are secreted proteins that link nervous system structure and function in vertebrates. They regulate neuronal survival, thus adjusting cell populations, and connectivity, enabling the formation of neuronal circuits. They also regulate patterns of dendrites and axons, synaptic function, memory, learning, and cognition; and abnormal neurotrophin function underlies psychiatric disorders. Despite such relevance for nervous system structure and function, neurotrophins have been missing from invertebrates. We show here the identification and functional demonstration of a neurotrophin family in the fruit fly, Drosophila. Our findings imply that the neurotrophins may be present in all animals with a centralised nervous system (motor and sensory systems) or brain, supporting the notion of a common origin for the brain in evolution. This work bridges a void in the understanding of the Drosophila and human nervous systems, and it opens the opportunity to use the powerful fruit fly for neurotrophin related studies. Members of the neurotrophin superfamily mediate critical roles in neuronal survival and targeting in the fruit flyDrosophila. Although this is an accepted role for neurotrophins in vertebrates, scant previous evidence has been able to demonstrate such a conserved role in invertebrates.
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Affiliation(s)
- Bangfu Zhu
- Neurodevelopment Group, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Jenny A Pennack
- Neurodevelopment Group, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Peter McQuilton
- Neurodevelopment Group, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Manuel G Forero
- Neurodevelopment Group, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Kenji Mizuguchi
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
- Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, University of Cambridge, United Kingdom
- National Institute of Biomedical Innovation, Osaka, Japan
| | - Ben Sutcliffe
- Neurodevelopment Group, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Chun-Jing Gu
- Neurodevelopment Group, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Janine C Fenton
- Neurodevelopment Group, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Alicia Hidalgo
- Neurodevelopment Group, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
- * To whom correspondence should be addressed. E-mail:
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62
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Alternative complement activity in the egg cytosol of amphioxus Branchiostoma belcheri: evidence for the defense role of maternal complement components. PLoS One 2009; 4:e4234. [PMID: 19156196 PMCID: PMC2617767 DOI: 10.1371/journal.pone.0004234] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2008] [Accepted: 12/12/2008] [Indexed: 11/28/2022] Open
Abstract
Background The eggs in most invertebrates are fertilized externally, and therefore their resulting embryos are exposed to an environment full of microbes, many of which are pathogens capable of killing other organisms. How the developing embryos of invertebrates defend themselves against pathogenic attacks is an intriguing question to biologists, and remains largely unknown. Methodology/Principal Findings Here we clearly demonstrated that the egg cytosol prepared from the newly fertilized eggs of amphioxus Branchiostoma belcheri, an invertebrate chordate, was able to inhibit the growth of both the Gram-negative bacterium Vibrio anguillarum and the Gram-positive bacterium Staphylococcus aureus. All findings point to that it is the complement system operating via the alternative pathway that is attributable to the bacteriostatic activity. Conclusions/Significance This appears to be the first report providing the evidence for the functional role of the maternal complement components in the eggs of invertebrate species, paving the way for the study of maternal immunity in other invertebrate organisms whose eggs are fertilized in vitro. It also supports the notion that the early developing embryos share some defense mechanisms common with the adult species.
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63
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Evolution of MDA-5/RIG-I-dependent innate immunity: independent evolution by domain grafting. Proc Natl Acad Sci U S A 2008; 105:17040-5. [PMID: 18971330 DOI: 10.1073/pnas.0804956105] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Type I Interferons (IFNs) are requisite components in antiviral innate immunity. Classically, a Toll-like receptor-dependent pathway induces type I interferons. However, recent recognition of melanoma differentiation associated gene-5 (MDA-5) and retinoic acid inducible gene-I (RIG-I) as primary sensors of RNA viruses for type I interferon induction highlights a potentially unique pathway for innate immunity. Our present investigation tracing the phylogenetic origin of MDA-5 and RIG-I domain arrangement (CARD1-CARD2-helicase-DEAD/DEAH) indicates that these proteins originated specifically in mammals, firmly linking this family of proteins with interferons in a highly derived evolutionary development of innate immunity. MDA-5, but not RIG-I, orthologs are found in fish, indicating that MDA-5 might have evolved before RIG-I. Our analyses also reveal that the MDA-5 and RIG-I domain arrangement evolved independently by domain grafting and not by a simple gene-duplication event of the entire four-domain arrangement, which may have been initiated by differential sensitivity of these proteins to viral infection.
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64
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Hemmrich G, Bosch TC. Compagen, a comparative genomics platform for early branching metazoan animals, reveals early origins of genes regulating stem-cell differentiation. Bioessays 2008; 30:1010-8. [DOI: 10.1002/bies.20813] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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65
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Rast JP, Messier-Solek C. Marine invertebrate genome sequences and our evolving understanding of animal immunity. THE BIOLOGICAL BULLETIN 2008; 214:274-283. [PMID: 18574104 DOI: 10.2307/25470669] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Animal immunity is under intense evolutionary pressure, and the mechanisms that carry out recognition and elimination of pathogens are among the most rapidly evolving genetic systems. It is increasingly apparent that this has led to the emergence of novel molecular mechanisms not only among vertebrates, where immunity is by far best characterized, but also across invertebrate phyla. This propensity for rapid divergence has been a serious obstacle for progress in the field of comparative immunology. The variety of recent genome sequences from marine invertebrates representing new phyla offers a means to move forward in this area. Genome sequences provide much improved sensitivity for the detection of gene homologs and a framework for unbiased computational and experimental searches for novel immune mediators. Furthermore, new genomes now offer a more complete and unbiased view of immunity across bilaterian phyla, especially among deuterostomes. In this review we summarize these findings with particular attention toward immunity in Strongylocentrotus purpuratus, the purple sea urchin, and outline the changing perspective on the evolution of deuterostome immunity.
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Affiliation(s)
- Jonathan P Rast
- Department of Medical Biophysics, University of Toronto, Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Rm. S126B, Toronto, Ontario M4N 3M5, Canada.
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66
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Roy CR, Mocarski ES. Pathogen subversion of cell-intrinsic innate immunity. Nat Immunol 2008; 8:1179-87. [PMID: 17952043 DOI: 10.1038/ni1528] [Citation(s) in RCA: 136] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The mammalian immune system has evolved under continuous selective pressure from a wide range of microorganisms that colonize and replicate in animal hosts. A complex set of signaling networks initiate both innate and adaptive immunity in response to the diverse pathogens that mammalian hosts encounter. In response, viral and microbial pathogens have developed or acquired sophisticated mechanisms to avoid, counteract and subvert sensors, signaling networks and a range of effector functions that constitute the host immune response. This balance of host response and pathogen countermeasures contributes to chronic infection in highly adapted pathogens that have coevolved with their host. In this review we outline some of the themes that are beginning to emerge in the mechanisms by which pathogens subvert the early innate immune response.
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Affiliation(s)
- Craig R Roy
- Section of Microbial Pathogenesis, Yale University School of Medicine, Boyer Center for Molecular Medicine, New Haven, Connecticut 06535, USA
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