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Trauer-Kizilelma U, Hilker M. Insect parents improve the anti-parasitic and anti-bacterial defence of their offspring by priming the expression of immune-relevant genes. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2015; 64:91-99. [PMID: 26255689 DOI: 10.1016/j.ibmb.2015.08.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 07/28/2015] [Accepted: 08/03/2015] [Indexed: 06/04/2023]
Abstract
Insect parents that experienced an immune challenge are known to prepare (prime) the immune activity of their offspring for improved defence. This phenomenon has intensively been studied by analysing especially immunity-related proteins. However, it is unknown how transgenerational immune priming affects transcript levels of immune-relevant genes of the offspring upon an actual threat. Here, we investigated how an immune challenge of Manduca sexta parents affects the expression of immune-related genes in their eggs that are attacked by parasitoids. Furthermore, we addressed the question whether the transgenerational immune priming of expression of genes in the eggs is still traceable in adult offspring. Our study revealed that a parental immune challenge did not affect the expression of immune-related genes in unparasitised eggs. However, immune-related genes in parasitised eggs of immune-challenged parents were upregulated to a higher level than those in parasitised eggs of unchallenged parents. Hence, this transgenerational immune priming of the eggs was detected only "on demand", i.e. upon parasitoid attack. The priming effects were also traceable in adult female progeny of immune-challenged parents which showed higher transcript levels of several immune-related genes in their ovaries than non-primed progeny. Some of the primed genes showed enhanced expression even when the progeny was left unchallenged, whereas other genes were upregulated to a greater extent in primed female progeny than non-primed ones only when the progeny itself was immune-challenged. Thus, the detection of transgenerational immune priming strongly depends on the analysed genes and the presence or absence of an actual threat for the offspring. We suggest that M. sexta eggs laid by immune-challenged parents "afford" to upregulate the transcription of immunity-related genes only upon attack, because they have the chance to be endowed by parentally directly transferred protective proteins.
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Affiliation(s)
- Ute Trauer-Kizilelma
- Institute of Biology, Dahlem Centre of Plant Sciences, Freie Universität Berlin, Haderslebener Str. 9, 12163 Berlin, Germany
| | - Monika Hilker
- Institute of Biology, Dahlem Centre of Plant Sciences, Freie Universität Berlin, Haderslebener Str. 9, 12163 Berlin, Germany.
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102
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Trauer-Kizilelma U, Hilker M. Impact of transgenerational immune priming on the defence of insect eggs against parasitism. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2015; 51:126-33. [PMID: 25790896 DOI: 10.1016/j.dci.2015.03.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 03/09/2015] [Accepted: 03/10/2015] [Indexed: 05/28/2023]
Abstract
Insects are known to prime the immune state of their offspring. However, although the beginning of insect life, the egg stage, is often greatly endangered by parasitism, no knowledge is available regarding whether transgenerational immune priming improves the immune responses of insect eggs to actual parasitoid attacks. Our study revealed suppression of the development of parasitoids in transgenerationally immune-primed Manduca sexta eggs and reduced emergence rates of parasitoids from these eggs. The higher defence efficiency of immune-primed M. sexta eggs against parasitoids was in agreement with the increased antibacterial activity and phenoloxidase activity of these eggs in response to parasitism compared to the eggs of control parents. Our study showed that immunochallenged insect parents could enable their offspring already in the egg stage to defend more efficiently against parasitic invaders. We discuss whether M. sexta benefits from transgenerational immune priming of eggs by limiting the population growth of egg parasitoids.
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Affiliation(s)
- Ute Trauer-Kizilelma
- Institute of Biology, Dahlem Centre of Plant Sciences, Freie Universität Berlin, Haderslebener Str. 9, Berlin 12163, Germany
| | - Monika Hilker
- Institute of Biology, Dahlem Centre of Plant Sciences, Freie Universität Berlin, Haderslebener Str. 9, Berlin 12163, Germany.
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103
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Salmela H, Amdam GV, Freitak D. Transfer of Immunity from Mother to Offspring Is Mediated via Egg-Yolk Protein Vitellogenin. PLoS Pathog 2015; 11:e1005015. [PMID: 26230630 PMCID: PMC4521805 DOI: 10.1371/journal.ppat.1005015] [Citation(s) in RCA: 134] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 06/09/2015] [Indexed: 11/19/2022] Open
Abstract
Insect immune systems can recognize specific pathogens and prime offspring immunity. High specificity of immune priming can be achieved when insect females transfer immune elicitors into developing oocytes. The molecular mechanism behind this transfer has been a mystery. Here, we establish that the egg-yolk protein vitellogenin is the carrier of immune elicitors. Using the honey bee, Apis mellifera, model system, we demonstrate with microscopy and western blotting that vitellogenin binds to bacteria, both Paenibacillus larvae--the gram-positive bacterium causing American foulbrood disease--and to Escherichia coli that represents gram-negative bacteria. Next, we verify that vitellogenin binds to pathogen-associated molecular patterns; lipopolysaccharide, peptidoglycan and zymosan, using surface plasmon resonance. We document that vitellogenin is required for transport of cell-wall pieces of E. coli into eggs by imaging tissue sections. These experiments identify vitellogenin, which is distributed widely in oviparous species, as the carrier of immune-priming signals. This work reveals a molecular explanation for trans-generational immunity in insects and a previously undescribed role for vitellogenin.
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Affiliation(s)
- Heli Salmela
- Centre of Excellence in Biological Interactions, University of Helsinki, Helsinki, Finland & University of Jyväskylä, Jyväskylä, Finland
| | - Gro V. Amdam
- School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
- Department of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences, Aas, Norway
| | - Dalial Freitak
- Centre of Excellence in Biological Interactions, University of Helsinki, Helsinki, Finland & University of Jyväskylä, Jyväskylä, Finland
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104
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Insects as models to study the epigenetic basis of disease. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2015; 118:69-78. [DOI: 10.1016/j.pbiomolbio.2015.02.009] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 01/06/2015] [Accepted: 02/23/2015] [Indexed: 12/17/2022]
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105
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Kangassalo K, Valtonen TM, Roff D, Pölkki M, Dubovskiy IM, Sorvari J, Rantala MJ. Intra- and trans-generational effects of larval diet on susceptibility to an entomopathogenic fungus, Beauveria bassiana
, in the greater wax moth, Galleria mellonella. J Evol Biol 2015; 28:1453-64. [DOI: 10.1111/jeb.12666] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 05/11/2015] [Indexed: 11/30/2022]
Affiliation(s)
- K. Kangassalo
- Department of Biology; Section of Ecology; University of Turku; Turku Finland
| | - T. M. Valtonen
- Department of Biology; Section of Ecology; University of Turku; Turku Finland
| | - D. Roff
- Department of Biology; University of California; Riverside CA USA
| | - M. Pölkki
- Department of Biology; Section of Ecology; University of Turku; Turku Finland
| | - I. M. Dubovskiy
- Institute of Animal Systematics and Ecology; Siberian Branch of Russian Academy of Science; Novosibirsk Russia
| | - J. Sorvari
- Department of Environmental Science; University of Eastern Finland; Kuopio Finland
| | - M. J. Rantala
- Department of Biology; Section of Ecology; University of Turku; Turku Finland
- Turku Brain and Mind Center; University of Turku; Turku Finland
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106
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Fisher JJ, Hajek AE. Maternal Exposure of a Beetle to Pathogens Protects Offspring against Fungal Disease. PLoS One 2015; 10:e0125197. [PMID: 25938586 PMCID: PMC4418818 DOI: 10.1371/journal.pone.0125197] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 03/13/2015] [Indexed: 11/18/2022] Open
Abstract
Maternal exposure to an immune challenge can convey enhanced immunity to invertebrate offspring in the next generation. We investigated whether maternal exposure of the Asian longhorned beetle, Anoplophora glabripennis, to two species of the fungus Metarhizium or the bacterium Serratia marcescens elicited transgenerational immune priming (TGIP). We tested specificity of this protection and whether occurrence of TGIP was dependent on maternal exposure to living versus dead pathogens. Our results show that TGIP occurred and protected offspring against Metarhizium brunneum. Maternal exposure to S. marcescens provided non-specific protection to offspring against a fungal pathogen, but TGIP in response to Metarhizium only occurred when offspring were exposed to the same fungal species that was used to prime mothers. Moreover, TGIP in response to M. brunneum occurred only after maternal exposure to living rather than dead fungus. Our findings suggest that occurrence of TGIP could be both specific and dependent on whether the pathogen was alive.
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Affiliation(s)
- Joanna J. Fisher
- Department of Entomology, Cornell University, Ithaca, New York, United States of America
- * E-mail:
| | - Ann E. Hajek
- Department of Entomology, Cornell University, Ithaca, New York, United States of America
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107
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Shikano I, Oak MC, Halpert‐Scanderbeg O, Cory JS. Trade‐offs between transgenerational transfer of nutritional stress tolerance and immune priming. Funct Ecol 2015. [DOI: 10.1111/1365-2435.12422] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Ikkei Shikano
- Department of Biological Sciences Simon Fraser University Burnaby BC V5A1S6 Canada
| | - Miranda C. Oak
- Department of Biological Sciences Simon Fraser University Burnaby BC V5A1S6 Canada
| | | | - Jenny S. Cory
- Department of Biological Sciences Simon Fraser University Burnaby BC V5A1S6 Canada
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108
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Eggert H, Diddens-de Buhr MF, Kurtz J. A temperature shock can lead to trans-generational immune priming in the Red Flour Beetle, Tribolium castaneum. Ecol Evol 2015; 5:1318-26. [PMID: 25859336 PMCID: PMC4377274 DOI: 10.1002/ece3.1443] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 01/27/2015] [Accepted: 01/31/2015] [Indexed: 02/04/2023] Open
Abstract
Trans-generational immune priming (TGIP) describes the transfer of immune stimulation to the next generation. As stress and immunity are closely connected, we here address the question whether trans-generational effects on immunity and resistance can also be elicited by a nonpathogen stress treatment of parents. General stressors have been shown to induce immunity to pathogens within individuals. However, to our knowledge, it is as of yet unknown whether stress can also induce trans-generational effects on immunity and resistance. We exposed a parental generation (mothers, fathers, or both parents) of the red flour beetle Tribolium castaneum, a species where TGIP has been previously been demonstrated, to either a brief heat or cold shock and examined offspring survival after bacterial infection with the entomopathogen Bacillus thuringiensis. We also studied phenoloxidase activity, a key enzyme of the insect innate immune system that has previously been demonstrated to be up-regulated upon TGIP. We quantified parental fecundity and offspring developmental time to evaluate whether trans-generational priming might have costs. Offspring resistance was found to be significantly increased when both parents received a cold shock. Offspring phenoloxidase activity was also higher when mothers or both parents were cold-shocked. By contrast, parental heat shock reduced offspring phenoloxidase activity. Moreover, parental cold or heat shock delayed offspring development. In sum, we conclude that trans-generational priming for resistance could not only be elicited by pathogens or pathogen-derived components, but also by more general cues that are indicative of a stressful environment. The interaction between stress responses and the immune system might play an important role also for trans-generational effects.
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Affiliation(s)
- Hendrik Eggert
- Institute for Evolution and Biodiversity, Westfälische Wilhelms-Universität Münster Hüfferstraße 1, Münster, DE-48149, Germany
| | - Maike F Diddens-de Buhr
- Institute for Evolution and Biodiversity, Westfälische Wilhelms-Universität Münster Hüfferstraße 1, Münster, DE-48149, Germany
| | - Joachim Kurtz
- Institute for Evolution and Biodiversity, Westfälische Wilhelms-Universität Münster Hüfferstraße 1, Münster, DE-48149, Germany
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109
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Tate AT, Graham AL. Trans‐generational priming of resistance in wild flour beetles reflects the primed phenotypes of laboratory populations and is inhibited by co‐infection with a common parasite. Funct Ecol 2015. [DOI: 10.1111/1365-2435.12411] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ann T. Tate
- Department of Ecology and Evolutionary Biology Princeton University 106A Guyot Hall Princeton NJ 08544 USA
| | - Andrea L. Graham
- Department of Ecology and Evolutionary Biology Princeton University 106A Guyot Hall Princeton NJ 08544 USA
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110
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Norouzitallab P, Biswas P, Baruah K, Bossier P. Multigenerational immune priming in an invertebrate parthenogenetic Artemia to a pathogenic Vibrio campbellii. FISH & SHELLFISH IMMUNOLOGY 2015; 42:426-429. [PMID: 25433135 DOI: 10.1016/j.fsi.2014.11.029] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 11/18/2014] [Accepted: 11/20/2014] [Indexed: 06/04/2023]
Affiliation(s)
- Parisa Norouzitallab
- Lab of Aquaculture & Artemia Reference Center, Department of Animal Production, Faculty of Bioscience Engineering, Ghent University, Rozier 44, Gent 9000, Belgium
| | - Priyanka Biswas
- Lab of Aquaculture & Artemia Reference Center, Department of Animal Production, Faculty of Bioscience Engineering, Ghent University, Rozier 44, Gent 9000, Belgium
| | - Kartik Baruah
- Lab of Aquaculture & Artemia Reference Center, Department of Animal Production, Faculty of Bioscience Engineering, Ghent University, Rozier 44, Gent 9000, Belgium
| | - Peter Bossier
- Lab of Aquaculture & Artemia Reference Center, Department of Animal Production, Faculty of Bioscience Engineering, Ghent University, Rozier 44, Gent 9000, Belgium.
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111
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Trevijano-Contador N, Herrero-Fernández I, García-Barbazán I, Scorzoni L, Rueda C, Rossi SA, García-Rodas R, Zaragoza O. Cryptococcus neoformans induces antimicrobial responses and behaves as a facultative intracellular pathogen in the non mammalian model Galleria mellonella. Virulence 2015; 6:66-74. [PMID: 25531532 PMCID: PMC4603429 DOI: 10.4161/21505594.2014.986412] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 10/05/2014] [Accepted: 11/06/2014] [Indexed: 11/19/2022] Open
Abstract
Cryptococcus neoformans is an encapsulated opportunistic fungal pathogen that is found in multiple niches in the environment and that can cause fatal meningoencephalitis in susceptible patients, mainly HIV+ individuals. Cryptococcus also infects environmental hosts such as nematodes, insects and plants. In particular, C. neoformans can kill the lepidopteran Galleria mellonella, which offers a useful tool to study microbial virulence and drug efficacy. Galleria mellonella immunity relies on innate responses based on melanization, accumulation of antimicrobial peptides, and cellular responses as phagocytosis or multicellular encapsulation. In this work we have investigated the immune response of G. mellonella during cryptococcal infection. We found that G. mellonella infected with C. neoformans had a high lytic activity in their hemolymph. This response was temperature- and capsule-dependent. During interaction with phagocytic cells, C. neoformans behaved as an intracellular pathogen since it could replicate within hemocytes. Non-lytic events were also observed. In contrast to Candida species, C. neoformans did not induce melanization of G. mellonella after infection. Finally, passage of C. neoformans through G. mellonella resulted in changes in capsule structure as it has been also reported during infection in mammals. Our results highlight that G. mellonella is an optimal model to investigate innate immune responses against C. neoformans.
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Affiliation(s)
- Nuria Trevijano-Contador
- Mycology Reference Laboratory; National Center for Microbiology; Instituto de Salud Carlos III; Carretera Majadahonda-Pozuelo, Km2; Majadahonda, 28220, Madrid, Spain
| | - Inés Herrero-Fernández
- Mycology Reference Laboratory; National Center for Microbiology; Instituto de Salud Carlos III; Carretera Majadahonda-Pozuelo, Km2; Majadahonda, 28220, Madrid, Spain
| | - Irene García-Barbazán
- Mycology Reference Laboratory; National Center for Microbiology; Instituto de Salud Carlos III; Carretera Majadahonda-Pozuelo, Km2; Majadahonda, 28220, Madrid, Spain
| | - Liliana Scorzoni
- Mycology Reference Laboratory; National Center for Microbiology; Instituto de Salud Carlos III; Carretera Majadahonda-Pozuelo, Km2; Majadahonda, 28220, Madrid, Spain
- Laboratório de Micologia Clínica; Faculdade de Ciências Farmacêuticas; R. Expedicionários do Brasil, 1621, CEP. 14801–902, Araraquara, São Paulo, Brazil
| | - Cristina Rueda
- Mycology Reference Laboratory; National Center for Microbiology; Instituto de Salud Carlos III; Carretera Majadahonda-Pozuelo, Km2; Majadahonda, 28220, Madrid, Spain
| | - Suélen Andreia Rossi
- Mycology Reference Laboratory; National Center for Microbiology; Instituto de Salud Carlos III; Carretera Majadahonda-Pozuelo, Km2; Majadahonda, 28220, Madrid, Spain
- Laboratório de Micologia Clínica; Faculdade de Ciências Farmacêuticas; R. Expedicionários do Brasil, 1621, CEP. 14801–902, Araraquara, São Paulo, Brazil
| | - Rocío García-Rodas
- Mycology Reference Laboratory; National Center for Microbiology; Instituto de Salud Carlos III; Carretera Majadahonda-Pozuelo, Km2; Majadahonda, 28220, Madrid, Spain
| | - Oscar Zaragoza
- Mycology Reference Laboratory; National Center for Microbiology; Instituto de Salud Carlos III; Carretera Majadahonda-Pozuelo, Km2; Majadahonda, 28220, Madrid, Spain
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112
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Jacobs CGC, Spaink HP, van der Zee M. The extraembryonic serosa is a frontier epithelium providing the insect egg with a full-range innate immune response. eLife 2014; 3:e04111. [PMID: 25487990 PMCID: PMC4358341 DOI: 10.7554/elife.04111] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 11/10/2014] [Indexed: 01/23/2023] Open
Abstract
Drosophila larvae and adults possess a potent innate immune response, but the response of Drosophila eggs is poor. In contrast to Drosophila, eggs of the beetle Tribolium are protected by a serosa, an extraembryonic epithelium that is present in all insects except higher flies. In this study, we test a possible immune function of this frontier epithelium using Tc-zen1 RNAi-mediated deletion. First, we show that bacteria propagate twice as fast in serosa-less eggs. Then, we compare the complete transcriptomes of wild-type, control RNAi, and Tc-zen1 RNAi eggs before and after sterile or septic injury. Infection induces genes involved in Toll and IMD-signaling, melanisation, production of reactive oxygen species and antimicrobial peptides in wild-type eggs but not in serosa-less eggs. Finally, we demonstrate constitutive and induced immune gene expression in the serosal epithelium using in situ hybridization. We conclude that the serosa provides insect eggs with a full-range innate immune response.
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Affiliation(s)
| | - Herman P Spaink
- Institute of Biology, Leiden University, Leiden, Netherlands
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113
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Shi ZH, Lin YT, Hou YM. Mother-derived trans-generational immune priming in the red palm weevil, Rhynchophorus ferrugineus Olivier (Coleoptera, Dryophthoridae). BULLETIN OF ENTOMOLOGICAL RESEARCH 2014; 104:742-750. [PMID: 25208627 DOI: 10.1017/s0007485314000583] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Rhynchophorus ferrugineus (Coleoptera, Curculionidae) is the most destructive pest of palm trees worldwide containing it invasive areas, such as the southern part of China. It is always emphasized to develop integrated pest management based on biological agents, but their success is not very exciting. Presently, the immune defenses of this pest against biological agents attract scarce attention. It is still unclear whether immune priming also generally occurs in insect pests and in response to different pathogens. Our results indicated that previous challenge of bacteria pathogen enhanced the magnitude of phenoloxidase activity and antibacterial activity in R. ferrugineus larvae against the secondary infection. Furthermore, trans-generational immune priming was also determined in this pest, and only challenged R. ferrugineus mothers transferred the immune protection to their offspring which suggested males and females of this pest might have evolved different strategies on the investment of delivering immune protection to their offspring. Importantly, our data provide the evidence to suggest that different kinds of biological control agents might be used alternatively or in combination to fight against R. ferrugineus because of the existence of immune priming with low species-specific level. On the other hand, for this invasive pest, the immune priming may also facilitate its adaptation and dispersal in the new regions.
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Affiliation(s)
- Z H Shi
- Key Laboratory of Integrated Pest Management of Fujian-Taiwan Crops,Ministry of Agriculture,China
| | - Y T Lin
- Key Laboratory of Integrated Pest Management of Fujian-Taiwan Crops,Ministry of Agriculture,China
| | - Y M Hou
- Key Laboratory of Integrated Pest Management of Fujian-Taiwan Crops,Ministry of Agriculture,China
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114
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Jacobs CGC, Wang Y, Vogel H, Vilcinskas A, van der Zee M, Rozen DE. Egg survival is reduced by grave-soil microbes in the carrion beetle, Nicrophorus vespilloides. BMC Evol Biol 2014; 14:208. [PMID: 25260512 PMCID: PMC4189599 DOI: 10.1186/s12862-014-0208-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Accepted: 09/22/2014] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND Nicrophorus vespilloides eggs are deposited into the soil in close proximity to the decomposing vertebrate carcasses that these insects use as an obligate resource to rear their offspring. Eggs in this environment potentially face significant risks from the bacteria that proliferate in the grave-soil environment following nutrient influx from the decomposing carcass. Our aims in this paper are twofold: first, to examine the fitness effects of grave-soil bacteria to eggs, and second, to quantify egg immunocompetence as a defence against these bacteria. RESULTS Our results provide strong evidence that grave-soil microbes significantly reduce the survival of Nicrophorus eggs. Females provided with microbe rich carcasses to rear broods laid fewer eggs that were less likely to hatch than females given uncontaminated carcasses. Furthermore, we show that egg hatch success is significantly reduced by bacterial exposure. Using a split-brood design, which controlled for intrinsic differences in eggs produced by different females, we found that eggs washed free of surface-associated bacteria show increased survival compared to unwashed eggs. By contrast, eggs exposed to the entomopathogen Serratia marcescens show decreased survival compared to unexposed eggs. We next tested the immune competence of eggs under challenge from bacterial infection, and found that eggs lacked endogenous production of antimicrobial peptides, despite well-developed responses in larvae. Finally, we found that despite lacking immunity, N. vespilloides eggs produce an extraembryonic serosa, indicating that the serosa has lost its immune inducing capacity in this species. CONCLUSIONS The dependency on ephemeral resources might strongly select for fast developing animals. Our results suggest that Nicrophorus carrion beetles, and other species developing on ephemeral resources, face a fundamental trade-off between egg immunity and development time.
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115
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Mukherjee K, Vilcinskas A. Development and immunity-related microRNAs of the lepidopteran model host Galleria mellonella. BMC Genomics 2014; 15:705. [PMID: 25149864 PMCID: PMC4156658 DOI: 10.1186/1471-2164-15-705] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Accepted: 08/19/2014] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND MicroRNAs (miRNAs) are small non-coding RNAs that act as key players in the post-transcriptional regulation of protein synthesis. Although little is known about their role in complex physiological processes such as development and immunity, our knowledge is expanding rapidly, thanks to the use of model systems. The larvae of the greater wax moth Galleria mellonella are now established as model hosts for pathogens that infect insects or humans. To build on our previously-reported comprehensive G. mellonella transcriptome, here we describe the identification and analysis of development and immunity-related miRNAs, thus providing valuable additional data to promote the use of this model host for the analysis of complex processes. RESULTS To screen for miRNAs that are differentially expressed in G. mellonella (1) during metamorphosis or (2) following infection with the entomopathogenic bacterium Serratia entomophila or (3) with the parasitic fungus Metarhizium anisopliae, we designed a microarray containing more than 2000 insect miRNA probe sequences. We identified miRNAs that were significantly expressed in pre-pupae (16), pupae (22) and last-instar larvae infected with M. anisopliae (1) in comparison with untreated last-instar larvae which were used as a reference. We then used our transcriptomic database to identify potential 3' untranslated regions that form miRNA-mRNA duplexes by considering both base pair complementarity and minimum free energy hybridization. We confirmed the co-expression of selected miRNAs (such as miR-71, miR-263a and miR-263b) with their predicted target mRNAs in last-instar larvae, pre-pupae and pupae by RT-PCR. We also identified miRNAs that were expressed in response to infection with bacterial or fungal pathogens, and one miRNA that may act as a candidate mediator of trans-generational immune priming. CONCLUSIONS This is the first study to identify miRNAs that are predicted to regulate genes expressed during metamorphosis or in response to infection in the lepidopteran model host G. mellonella.
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Affiliation(s)
| | - Andreas Vilcinskas
- Fraunhofer Institute for Molecular Biology and Applied Ecology, Department of Bioresources, Winchester Str, 2, 35395 Giessen, Germany.
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116
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Trevijano-Contador N, Zaragoza O. Expanding the use of alternative models to investigate novel aspects of immunity to microbial pathogens. Virulence 2014; 5:454-6. [PMID: 24717215 PMCID: PMC4063805 DOI: 10.4161/viru.28775] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Affiliation(s)
- Nuria Trevijano-Contador
- Mycology Reference Laboratory; National Centre for Microbiology; Instituto de Salud Carlos III; Madrid, Spain
| | - Oscar Zaragoza
- Mycology Reference Laboratory; National Centre for Microbiology; Instituto de Salud Carlos III; Madrid, Spain
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Kissin I, Szallasi A. Therapeutic targeting of TRPV1 by resiniferatoxin, from preclinical studies to clinical trials. Curr Top Med Chem 2011. [PMID: 21671878 DOI: 10.1101/128884] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
In primary sensory neurons, the capsaicin receptor TRPV1 functions as a molecular integrator for a broad range of seemingly unrelated chemical and physical noxious stimuli, including heat and altered pH. Indeed, TRPV1 is thought to be a major transducer of the thermal hyperalgesia that follows inflammation and tissue injury as this response is impaired in TRPV1-deficient mice. Following the molecular cloning of TRPV1 in 1997, over a dozen companies embarked on efforts to find clinically useful TRPV1 antagonists, but side-effects and limited efficacy have thus far prevented any compounds from progressing beyond phase II. This has rekindled interest in desensitization of nociceptive neurons to TRPV1 agonists (e.g. capsaicin and its ultrapotent analog resiniferatoxin) as an alternative pharmacological approach to block pain in the periphery where it is generated. The clinical value of capsaicin is, however, limited by its unfavorable irritancy to desensitization ratio. In animal experiments, resiniferatoxin treatment is a powerful approach to achieve long-lasting analgesia. In patients with overactive bladder, intravesical resiniferatoxin improves bladder function (or even restores continence) without significant irritancy and/or toxicity. In this review, we argue that resiniferatoxin is an attractive alternative to capsaicin in that it achieves lasting desensitization without the side effects that complicate capsaicin therapy.
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Affiliation(s)
- Igor Kissin
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
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