uu.seUppsala universitets publikasjoner
Endre søk
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Melanization and Pathogenicity in the Insect, Tenebrio molitor, and the Crustacean, Pacifastacus leniusculus, by Aeromonas hydrophila AH-3
Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Jämförande fysiologi.
Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Jämförande fysiologi.
Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Jämförande fysiologi.
Vise andre og tillknytning
2010 (engelsk)Inngår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 5, nr 12, s. e15728-Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Aeromonas hydrophila is the most common Aeromonas species causing infections in human and other animals such as amphibians, reptiles, fish and crustaceans. Pathogenesis of Aeromonas species have been reported to be associated with virulence factors such as lipopolysaccharides (LPS), bacterial toxins, bacterial secretion systems, flagella, and other surface molecules. Several mutant strains of A. hydrophila AH-3 were initially used to study their virulence in two animal species, Pacifastacus leniusculus (crayfish) and Tenebrio molitor larvae (mealworm). The AH-3 strains used in this study have mutations in genes involving the synthesis of flagella, LPS structures, secretion systems, and some other factors, which have been reported to be involved in A. hydrophila pathogenicity. Our study shows that the LPS (O-antigen and external core) is the most determinant A. hydrophila AH-3 virulence factor in both animals. Furthermore, we studied the immune responses of these hosts to infection of virulent or non-virulent strains of A. hydrophila AH-3. The AH-3 wild type (WT) containing the complete LPS core is highly virulent and this bacterium strongly stimulated the prophenoloxidase activating system resulting in melanization in both crayfish and mealworm. In contrast, the ΔwaaE mutant which has LPS without O-antigen and external core was non-virulent and lost ability to stimulate this system and melanization in these two animals. The high phenoloxidase activity found in WT infected crayfish appears to result from a low expression of pacifastin, a prophenoloxidase activating enzyme inhibitor, and this gene expression was not changed in the ΔwaaE mutant infected animal and consequently phenoloxidase activity was not altered as compared to non-infected animals. Therefore we show that the virulence factors of A. hydrophila are the same regardless whether an insect or a crustacean is infected and the O-antigen and external core is essential for activation of the proPO system and as virulence factors for this bacterium.

sted, utgiver, år, opplag, sider
2010. Vol. 5, nr 12, s. e15728-
HSV kategori
Identifikatorer
URN: urn:nbn:se:uu:diva-141552DOI: 10.1371/journal.pone.0015728ISI: 000285793200045PubMedID: 21206752OAI: oai:DiVA.org:uu-141552DiVA, id: diva2:385777
Tilgjengelig fra: 2011-01-12 Laget: 2011-01-12 Sist oppdatert: 2017-12-11
Inngår i avhandling
1. Hemocyte Homeostasis and Infection in the Freshwater Crayfish, Pacifastacus leniusculus
Åpne denne publikasjonen i ny fane eller vindu >>Hemocyte Homeostasis and Infection in the Freshwater Crayfish, Pacifastacus leniusculus
2012 (engelsk)Licentiatavhandling, med artikler (Annet vitenskapelig)
sted, utgiver, år, opplag, sider
Uppsala: Department of Comparative Physiology, Uppsala University, 2012. s. 26
HSV kategori
Forskningsprogram
Biologi med inriktning mot jämförande fysiologi
Identifikatorer
urn:nbn:se:uu:diva-173690 (URN)
Presentation
2012-03-23, Lagerträdet 05:01021, Norbyvägen 18A, Uppsala, 08:55 (engelsk)
Opponent
Veileder
Forskningsfinansiär
Swedish Research Council, 621-2011-4797
Tilgjengelig fra: 2012-05-03 Laget: 2012-05-03 Sist oppdatert: 2012-05-03bibliografisk kontrollert
2. Melanization and Hemocyte Homeostasis  in the Freshwater Crayfish, Pacifastacus leniusculus
Åpne denne publikasjonen i ny fane eller vindu >>Melanization and Hemocyte Homeostasis  in the Freshwater Crayfish, Pacifastacus leniusculus
2013 (engelsk)Doktoravhandling, med artikler (Annet vitenskapelig)
Abstract [en]

Blood cells or hemocytes play important roles in immunity. They are a major source of many immune-related molecules such as antibodies in adaptive immunity of vertebrates and prophenoloxidase (proPO) in invertebrates. In the crayfish Pacifastacus leniusculus, the proPO-system has been reported to be an important component of immune responses against microorganisms. In this study, several mutant strains of Aeromonas hydrophila were used to reveal that LPS (lipopolysaccharide) is an important factor for the pathogenicity of A. hydrophila, strongly inducing the proPO system and melanization. This proPO activating system is a multistep process, which has to be tightly controlled to avoid the harmful side effects of toxic intermediates. Many regulating factors have been reported to fine-tune the proPO-system. In this study, the cleavage of caspase-1-like activity was shown to be a novel negative regulator of PO activity in crayfish. Moreover, the fragments obtained by cleavage of proPO by the proPO-activating enzyme and caspase-1-like protein increased bacterial clearance. Thus, the peptides generated also have important biological functions.

In addition to being a source of immune proteins, hemocytes also participate in phagocytosis, encapsulation, and nodulation. An infection normally causes a reduction of hemocyte numbers. Consequently, hemocyte homeostasis is important for maintaining appropriate hemocyte numbers in the circulation of the animal. This study shows that the reactive oxygen species level in the anterior proliferation center of crayfish hematopoietic tissue (HPT), together with cell proliferation, was increased during infection. Pl-β-thymosins were proposed to be involved in hemocyte homeostasis by increasing stem cell migration and thus increasing the circulating hemocyte number. Crayfish hemocyte numbers, as well astakine (Ast1 and Ast2) expression in hemocytes and HPT, were previously shown to be under circadian regulation. Here, we show that Ast1, Ast2, and proPO exhibit rhythmic expression in the crayfish brain similarly to their orthologs, prokineticin 1, prokineticin 2 and tyrosinase, respectively, in the zebrafish brain. Tyrosinase expression was detected in zebrafish brain cells while PO-positive cells were identified as hemocytes that had infiltrated into the crayfish brain. Therefore, this information suggests a close relationship between crayfish hemocytes and the crayfish brain as well as vertebrate neurons.

sted, utgiver, år, opplag, sider
Uppsala: Acta Universitatis Upsaliensis, 2013. s. 48
Serie
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1086
Emneord
melanization, prophenoloxidase, caspase, hematopoiesis, thymosin, astakine, circadian rhythm, reactive oxygen species, tyrosinase, prokineticin
HSV kategori
Identifikatorer
urn:nbn:se:uu:diva-209209 (URN)978-91-554-8774-4 (ISBN)
Disputas
2013-11-28, Lindahlssalen, EBC, Norbyvägen 18A, Uppsala, 10:00 (engelsk)
Opponent
Veileder
Tilgjengelig fra: 2013-11-06 Laget: 2013-10-15 Sist oppdatert: 2016-05-09

Open Access i DiVA

Fulltekst mangler i DiVA

Andre lenker

Forlagets fulltekstPubMed

Personposter BETA

Noonin, ChadanatJiravanichpaisal, PikulSöderhäll, IreneSöderhäll, Kenneth

Søk i DiVA

Av forfatter/redaktør
Noonin, ChadanatJiravanichpaisal, PikulSöderhäll, IreneSöderhäll, Kenneth
Av organisasjonen
I samme tidsskrift
PLoS ONE

Søk utenfor DiVA

GoogleGoogle Scholar

doi
pubmed
urn-nbn

Altmetric

doi
pubmed
urn-nbn
Totalt: 518 treff
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf