Relevant bibliographies by topics / Hemocyte

Contents

  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
  6. Reports

Academic literature on the topic 'Hemocyte'

Author: Grafiati
Published: 4 June 2021
Last updated: 9 March 2023

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Hemocyte.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Hemocyte"

1

Alavo, Thiery B. C., and Gary B. Dunphy. "Bacterial formyl peptides affect the innate cellular antimicrobial responses of larval Galleria mellonella (Insecta: Lepidoptera)." Canadian Journal of Microbiology 50, no. 4 (April 1, 2004): 279–89. http://dx.doi.org/10.1139/w04-014.

Full text
Abstract:
The non-self cellular (hemocytic) responses of Galleria mellonella larvae, including the attachment to slides and the removal of the bacteria Xenorhabdus nematophila and Bacillus subtilis from the hemolymph, were affected by N-formyl peptides. Both N-formyl methionyl-leucyl-phenylalanine (fMLF) and the ester derivative decreased hemocyte adhesion in vitro, and both elevated hemocyte counts and suppressed the removal of both X. nematophila and B. subtilis from the hemolymph in vivo. The amide derivative and the antagonist tertiary-butoxy-carbonyl-methionyl-leucyl-phenylalanine (tBOC) increased hemocyte attachment to glass. The fMLF suppressed protein discharge from monolayers of granular cells with and without bacterial stimulation, while tBOC stimulated protein discharge. The peptide tBOC offset the effects of fMLF in vitro and in vivo. This is the first report implying the existence of formyl peptide receptors on insect hemocytes in which the compounds fMLF and tBOC inhibited and activated hemocyte activity, respectively.Key words: formyl peptides, hemocytes, Xenorhabdus, Bacillus.
APA, Harvard, Vancouver, ISO, and other styles
2

Fisher, William S., and Mark Tamplin. "Environmental Influence on Activities and Foreign-Particle Binding by Hemocytes of American Oysters, Crassostrea virginica." Canadian Journal of Fisheries and Aquatic Sciences 45, no. 7 (July 1, 1988): 1309–15. http://dx.doi.org/10.1139/f88-153.

Full text
Abstract:
American oysters (Crassostrea virginia) from an estuarine and an oceanic habitat were held in the laboratory under various temperature and salinity regimes. After a month, their hemocytes were withdrawn from the adductor muscle and measured in vitro for time to spreading (TTS), time to spreading after an acute salinity increase (TTS + 12), rate of locomotion (ROL), and binding of fluorescent microspheres (beads). Bead binding was compared with binding of bacteria (Vibrio parahemolyticus). TTS and TTS + 12 measurements were negatively correlated with temperature whereas ROL and bead binding measurements were positively correlated with temperature. An acute rise in salinity (TTS + 12) increased the time required for hemocyte spreading. Spreading was faster, however, at higher salinities for acclimated oysters from both habitats. This finding contradicted previous results for estuarine oyster hemocytes and emphasized the role of environmental history and/or seasonality on hemocyte responses. Oceanic oysters from a less variable environment showed hemocytic responses consistent with previous studies.
APA, Harvard, Vancouver, ISO, and other styles
3

Bakopoulos, Daniel, Lauren Forbes Beadle, Katherine M. Esposito, Christen K. Mirth, Coral G. Warr, and Travis K. Johnson. "Insulin-Like Signalling Influences the Coordination of Larval Hemocyte Number with Body Size in Drosophila melanogaster." G3: Genes|Genomes|Genetics 10, no. 7 (April 27, 2020): 2213–20. http://dx.doi.org/10.1534/g3.120.401313.

Full text
Abstract:
Blood cells, known as hemocytes in invertebrates, play important and conserved roles in immunity, wound healing and tissue remodelling. The control of hemocyte number is therefore critical to ensure these functions are not compromised, and studies using Drosophila melanogaster are proving useful for understanding how this occurs. Recently, the embryonic patterning gene, torso-like (tsl), was identified as being required both for normal hemocyte development and for providing immunity against certain pathogens. Here, we report that Tsl is required specifically during the larval phase of hematopoiesis, and that tsl mutant larvae likely have reduced hemocyte numbers due to a reduced larval growth rate and compromised insulin signaling. Consistent with this, we find that impairing insulin-mediated growth, either by nutrient deprivation or genetically, results in fewer hemocytes. This is likely the result of impaired insulin-like signaling in the hemocytes themselves, since modulation of Insulin-like Receptor (InR) activity specifically in hemocytes causes concomitant changes to their population size in developing larvae. Taken together, our work reveals the strong relationship that exists between body size and hemocyte number, and suggests that insulin-like signaling contributes to, but is not solely responsible for, keeping these tightly aligned during larval development.
APA, Harvard, Vancouver, ISO, and other styles
4

Remillieux-Leschelle, Nathalie, Pedro Santamaria, and Neel B. Randsholt. "Regulation of Larval Hematopoiesis in Drosophila melanogaster: A Role for the multi sex combs Gene." Genetics 162, no. 3 (November 1, 2002): 1259–74. http://dx.doi.org/10.1093/genetics/162.3.1259.

Full text
Abstract:
Abstract Drosophila larval hematopoietic organs produce circulating hemocytes that ensure the cellular host defense by recognizing and neutralizing non-self or noxious objects through phagocytosis or encapsulation and melanization. Hematopoietic lineage specification as well as blood cell proliferation and differentiation are tightly controlled. Mutations in genes that regulate lymph gland cell proliferation and hemocyte numbers in the body cavity cause hematopoietic organ overgrowth and hemocyte overproliferation. Occasionally, mutant hemocytes invade self-tissues, behaving like neoplastic malignant cells. Two alleles of the Polycomb group (PcG) gene multi sex combs (mxc) were previously isolated as such lethal malignant blood neoplasm mutations. PcG genes regulate Hox gene expression in vertebrates and invertebrates and participate in mammalian hematopoiesis control. Hence we investigated the need for mxc in Drosophila hematopoietic organs and circulating hemocytes. We show that mxc-induced hematopoietic hyperplasia is cell autonomous and that mxc mainly controls plasmatocyte lineage proliferation and differentiation in lymph glands and circulating hemocytes. Loss of the Toll pathway, which plays a similar role in hematopoiesis, counteracted mxc hemocyte proliferation but not mxc hemocyte differentiation. Several PcG genes tested in trans had no effects on mxc hematopoietic phenotypes, whereas the trithorax group gene brahma is important for normal and mutant hematopoiesis control. We propose that mxc provides one of the regulatory inputs in larval hematopoiesis that control normal rates of plasmatocyte and crystal lineage proliferation as well as normal rates and timing of hemocyte differentiation.
APA, Harvard, Vancouver, ISO, and other styles
5

Moyetta, Natalia R., Fabián O. Ramos, Jimena Leyria, Lilián E. Canavoso, and Leonardo L. Fruttero. "Morphological and Ultrastructural Characterization of Hemocytes in an Insect Model, the Hematophagous Dipetalogaster maxima (Hemiptera: Reduviidae)." Insects 12, no. 7 (July 14, 2021): 640. http://dx.doi.org/10.3390/insects12070640.

Full text
Abstract:
Hemocytes, the cells present in the hemolymph of insects and other invertebrates, perform several physiological functions, including innate immunity. The current classification of hemocyte types is based mostly on morphological features; however, divergences have emerged among specialists in triatomines, the insect vectors of Chagas’ disease (Hemiptera: Reduviidae). Here, we have combined technical approaches in order to characterize the hemocytes from fifth instar nymphs of the triatomine Dipetalogaster maxima. Moreover, in this work we describe, for the first time, the ultrastructural features of D. maxima hemocytes. Using phase contrast microscopy of fresh preparations, five hemocyte populations were identified and further characterized by immunofluorescence, flow cytometry and transmission electron microscopy. The plasmatocytes and the granulocytes were the most abundant cell types, although prohemocytes, adipohemocytes and oenocytes were also found. This work sheds light on a controversial aspect of triatomine cell biology and physiology setting the basis for future in-depth studies directed to address hemocyte classification using non-microscopy-based markers.
APA, Harvard, Vancouver, ISO, and other styles
6

Perdomo-Morales, Rolando, Vivian Montero-Alejo, Leandro Rodríguez-Viera, and Erick Perera. "Evaluation of anticoagulants and hemocyte-maintaining solutions for the study of hemolymph components in the spiny lobster Panulirus argus (Latreille, 1804) (Decapoda: Achelata: Palinuridae)." Journal of Crustacean Biology 40, no. 2 (January 30, 2020): 213–17. http://dx.doi.org/10.1093/jcbiol/ruz099.

Full text
Abstract:
Abstract Functional studies on humoral or cellular responses in the hemolymph of crustaceans require the selection of suitable anticoagulant- and hemocyte-maintaining solutions. We studied the suitability of several anticoagulant- and hemocyte-maintaining solutions in the spiny lobster Panulirus argus (Latreille, 1804), with emphasis in the preservation of hemocyte number and viability. It was found that the modified Alsever solution was the ideal anticoagulant, while modified L-15 medium and Panulirus argus saline (PAS) were the best hemocyte-maintaining solutions. It is striking that whereas avoiding plasma clotting is relatively simple to achieve, avoiding lysis and aggregation of hemocytes could be challenging and variable among closely related crustaceans. The reasons are hardly known and might indicate different composition or sensitivity of both membrane-bound and soluble mediators in any of the three types of hemocytes identified among decapod crustaceans. Hemolymph volume average in P. argus was 10.5% of fresh body weight (more than 50 ml per adult individual), which makes this species an attractive model for functional studies of hemolymph components in crustaceans.
APA, Harvard, Vancouver, ISO, and other styles
7

Munari, Marco, Valerio Matozzo, Giuditta Benetello, Verena Riedl, Paolo Pastore, Denis Badocco, and Maria Gabriella Marin. "Exposure to Decreased pH and Caffeine Affects Hemocyte Parameters in the Mussel Mytilus galloprovincialis." Journal of Marine Science and Engineering 8, no. 4 (April 1, 2020): 238. http://dx.doi.org/10.3390/jmse8040238.

Full text
Abstract:
Combined effects of reduced pH, as predicted under climate change scenarios, and the most popular and widely used stimulant caffeine were assessed in hemocyte parameters of the mussel Mytilus galloprovincialis, being hemocytes involved in immune defense. Bivalves were exposed for one week to natural pH (8.1) and two reduced pH values (pH −0.4 units and pH −0.7 units). Exposure continued for additional two weeks, both in the absence and in the presence of environmentally relevant concentrations of caffeine (0.05 and 0.5 µg/L). Hemocyte parameters (total hemocyte count, hemocyte volume and diameter, neutral red uptake and hemocyte proliferation) were measured after 7 days of exposure to pH only, and after 14 (T1) and 21 (T2) days of exposure to the various pH*caffeine combinations. At all sampling times, pH significantly affected all the biological variables considered, whereas caffeine exhibited a significant influence at T2 only. Among the various hemocyte parameters, caffeine caused a significant increase in total hemocyte count at T2, and in hemocyte volume and diameter at both T1 and T2, when a significant interaction between pH and caffeine was also found. Overall, results demonstrated that hemocyte functionality was strongly influenced by the experimental conditions tested. Further studies are needed to assess combined effects of climate changes and emerging contaminants on bivalve immune system when challenged with environmental pathogens.
APA, Harvard, Vancouver, ISO, and other styles
8

Barracco, Margherita A., and Clarice T. Loch. "Ultrastructural studies of the hemocytes of Panstrongylus megistus (Hemiptera: Reduvidae)." Memórias do Instituto Oswaldo Cruz 84, no. 2 (June 1989): 171–88. http://dx.doi.org/10.1590/s0074-02761989000200005.

Full text
Abstract:
Ultrastructural analyses revealed the presence of six hemocyte types in the hemolymph of Panstrogylus megistus, partially confirming our previous results obtained through light microscopy. Prohemocytes: small, round hemocytes with a thin cytoplasm layer, espcieally rich in free ribosomes and poor in membranous systems. Plasmatocytes: polymorphic cells, whose cytoplasm contains many lysosomes and a well developed rough endoplasmic reticulum (RER).They are extremely phagocytic. Sometimes, they show a large vacuolation. Granulocytes: granular hemocytes whose granules show different degrees of electrondensity. Most of them, have an internal structuration. Coagulocytes: oval or elongated hemocytes, which show pronounced perinuclear cisternae as normally observed in coagulocytes. The cytoplasm is usually electrondense, poor in membranous systems and contains many labile granules. Oenocytoids: large and very stable hemocytes, whose homogeneous cytoplasme is rich in loose ribosomes and poor in membranous systems. Adipohemocytes: large cells, containing several characteristic lipid droplets. The cytoplasm is also rich in glycogen, RER and large mitochondria. The total and differential hemocyte count (THC and DHC) were also calculated for this reduviid. THC increases from 2,900 hemocytes/cubic millimeter of hemolymph in the 4th intar to 4,350 in the 5th and then, decreases to 1,950 in the adults. Plasmatocytes and coagulocytes are the predominant hemocyte types.
APA, Harvard, Vancouver, ISO, and other styles
9

Trainor, Jordann E., Pooja KR, and Nathan T. Mortimer. "Immune Cell Production Is Targeted by Parasitoid Wasp Virulence in a Drosophila–Parasitoid Wasp Interaction." Pathogens 10, no. 1 (January 8, 2021): 49. http://dx.doi.org/10.3390/pathogens10010049.

Full text
Abstract:
The interactions between Drosophila melanogaster and the parasitoid wasps that infect Drosophila species provide an important model for understanding host–parasite relationships. Following parasitoid infection, D. melanogaster larvae mount a response in which immune cells (hemocytes) form a capsule around the wasp egg, which then melanizes, leading to death of the parasitoid. Previous studies have found that host hemocyte load; the number of hemocytes available for the encapsulation response; and the production of lamellocytes, an infection induced hemocyte type, are major determinants of host resistance. Parasitoids have evolved various virulence mechanisms to overcome the immune response of the D. melanogaster host, including both active immune suppression by venom proteins and passive immune evasive mechanisms. We identified a previously undescribed parasitoid species, Asobara sp. AsDen, which utilizes an active virulence mechanism to infect D. melanogaster hosts. Asobara sp. AsDen infection inhibits host hemocyte expression of msn, a member of the JNK signaling pathway, which plays a role in lamellocyte production. Asobara sp. AsDen infection restricts the production of lamellocytes as assayed by hemocyte cell morphology and altered msn expression. Our findings suggest that Asobara sp. AsDen infection alters host signaling to suppress immunity.
APA, Harvard, Vancouver, ISO, and other styles
10

Trainor, Jordann E., Pooja KR, and Nathan T. Mortimer. "Immune Cell Production Is Targeted by Parasitoid Wasp Virulence in a Drosophila–Parasitoid Wasp Interaction." Pathogens 10, no. 1 (January 8, 2021): 49. http://dx.doi.org/10.3390/pathogens10010049.

Full text
Abstract:
The interactions between Drosophila melanogaster and the parasitoid wasps that infect Drosophila species provide an important model for understanding host–parasite relationships. Following parasitoid infection, D. melanogaster larvae mount a response in which immune cells (hemocytes) form a capsule around the wasp egg, which then melanizes, leading to death of the parasitoid. Previous studies have found that host hemocyte load; the number of hemocytes available for the encapsulation response; and the production of lamellocytes, an infection induced hemocyte type, are major determinants of host resistance. Parasitoids have evolved various virulence mechanisms to overcome the immune response of the D. melanogaster host, including both active immune suppression by venom proteins and passive immune evasive mechanisms. We identified a previously undescribed parasitoid species, Asobara sp. AsDen, which utilizes an active virulence mechanism to infect D. melanogaster hosts. Asobara sp. AsDen infection inhibits host hemocyte expression of msn, a member of the JNK signaling pathway, which plays a role in lamellocyte production. Asobara sp. AsDen infection restricts the production of lamellocytes as assayed by hemocyte cell morphology and altered msn expression. Our findings suggest that Asobara sp. AsDen infection alters host signaling to suppress immunity.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Hemocyte"

1

Saelee, Netnapa, Chadanat Noonin, Benjamas Nupan, Kingkamon Junkunlo, Amornrat Phongdara, Xionghui Lin, Kenneth Söderhäll, and Irene Söderhäll. "beta-Thymosins and Hemocyte Homeostasis in a Crustacean." Uppsala universitet, Jämförande fysiologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-200355.

Full text
Abstract:
Thymosin proteins are well known for their actin-binding activity. Thymosin beta 4 (T beta 4) has been associated with biological activities in tissue repair and cell migration via interaction with ATP-synthase in vertebrates, while the information of similar thymosin functions in invertebrates is limited. We have shown previously that ATP-synthase is present on the surface of crayfish hematopoietic tissue (HPT) cells, and that astakine 1 (Ast1, an invertebrate cytokine) was found to interact with this beta-subunit of ATP synthase. Here, we identified five different beta-thymosins from Pacifastacus leniusculus, designated Pl-beta-thymosin1-5. The two dominant isoforms in brain, HPT and hemocytes, Pl-beta-thymosin1 and 2, were chosen for functional studies. Both isoforms could bind to the b-subunit of ATP-synthase, and Pl-beta-thymosin1, but not Pl-beta-thymosin2, significantly increased extracellular ATP formation. Moreover, Pl-beta-thymosin1 stimulated HPT cell migration in vitro and Ast1 blocked this effect. Pl-beta-thymosin2 increased the circulating hemocyte number at an early stage after injection. Additionally, in vivo injection of Pl-beta-thymosin1 resulted in significant reduction of reactive oxygen species (ROS) production in crayfish HPT whereas Pl-beta-thymosin2 had a similar but transient effect. Both Pl-beta-thymosins induced the expression of Ast1 and superoxide dismutase (SOD) transcripts, while silencing of endogenous Pl-beta-thymosin 1 and 2 by RNAi resulted in significant reduction of the Ast1 and SOD transcripts. The diverse effects exhibited by Pl-beta-thymosin1 and Pl-beta-thymosin2 indicates that these proteins are involved in a complex interaction that regulates the hematopoietic stem cell proliferation and differentiation.
APA, Harvard, Vancouver, ISO, and other styles
2

Noonin, Chadanat. "Melanization and Hemocyte Homeostasis in the Freshwater Crayfish, Pacifastacus leniusculus." Doctoral thesis, Uppsala universitet, Jämförande fysiologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-209209.

Full text
Abstract:
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.
APA, Harvard, Vancouver, ISO, and other styles
3

Comber, Kate. "Investigation into the molecular mechanisms governing Drosophila embryonic hemocyte migration in vivo." Thesis, University of Bath, 2014. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.606669.

Full text
Abstract:
Accumulating evidence highlights the importance of studying the migration of cells within the context of their natural environment as manipulating the substrate on which a cell is migrating can have a dramatic impact on the mode/mechanisms employed by cells during migration. Central to this phenomenon is the requirement of adhesion to the ECM in order to gain traction during migration. Integrins constitute the main family of cell receptors involved in mediating cell-ECM interactions during motility. Whilst traditionally two-dimensional cell culture studies have placed emphasis on the importance of these receptors for spreading and migration, it has become evident that within more confined environments these receptors, at least for some cell types, are less crucial. In this research we utilise Drosophila embryonic hemocytes as an in vivo model for cell migration. We show that whilst hemocytes migrate within confined environments in vivo, these cells depend on integrins for powering both developmental and inflammatory migrations. Given the close association between these receptors and the actin cytoskeleton we were surprised to discover that removal of the main β integrin subunit, Myospheroid, did not affect cell spreading in vivo and had only a small impact on lamellipodial structure and dynamics. Furthermore we discovered that, in contrast to other cell types previously analysed, removal of this integrin subunit in hemocytes was not accompanied by an increase in the rate of actin retrograde flow within the protrusions, which we believe could reflect abrogation of a positive feedback between Rho, ROCK and Myosin II contraction. Instead, we discover a key role for integrins in regulating the microtubule cytoskeleton, in the maintenance of a polarised microtubule bundle, termed a ‘microtubule-arm’. Although the molecular mechanisms by which this stabilisation is coordinated have yet to be identified, this provides important insight into the co-regulation of adhesion and microtubule cytoskeleton important for the migratory behaviour of these cells. Cell migration reflects the complex and integrated regulation of the actin cytoskeleton by diverse families of actin regulatory proteins. Using hemocytes as a model system, we also explore the regulatory interactions between two main actin regulatory proteins, Diaphanous and Enabled, in vivo. Whilst the function of these proteins in the formation of filopodial protrusions is overlapping, recent research has highlighted the ability of these proteins to regulate the activity of one another. We find that co-expression of Enabled in hemocytes is able to rescue the morphological and migratory defects resulting from overexpression of active Diaphanous. Thus, data here presents Enabled as a negative regulator of Diaphanous, which may play an important role in the migration of hemocytes in vivo.
APA, Harvard, Vancouver, ISO, and other styles
4

Luce-Fedrow, Alison. "Drosophila melanogaster as a model for studying Ehrlichia chaffeensis infections." Diss., Kansas State University, 2010. http://hdl.handle.net/2097/11969.

Full text
Abstract:
Doctor of Philosophy
Department of Biology
Stephen Keith Chapes
Ehrlichia chaffeensis is an obligate, intracellular bacterium that causes human monocytic ehrlichiosis (HME). The bacteria are vectored by the Lone Star tick (Amblyomma americanum), which is found primarily in the Midwestern and Southeastern United States E. chaffeensis was first reported in 1986 and HME was designated a nationally reportable disease by the United States Centers for Disease Control in 1999. Ehrlichia grows in several mammalian cell lines, but NO consensus model for pathogenesis exists for arthropods or vertebrates. Moreover, the host genes required for intracellular growth of this bacteria are unknown. We first established that the bacteria could infect and replicate both in vitro and in vivo in Drosophila melanogaster S2 cells and adult flies, respectively. We performed microarrays on S2 cells, comparing host gene expression between permissive or non-permissive conditions for E. chaffeensis growth. A total of 210 permissive, exclusive and 83 non-permissive, exclusive genes were up-regulated greater than 1.5-fold above uninfected cells. We screened flies mutant for genes identified in our microarrays for their ability to support Ehrlichia replication. Five mutant stocks were resistant to infection with Ehrlichia (genes CG6479, separation anxiety, CG3044, CG6364, and CG6543). qRT-PCR confirmed that bacterial load was decreased in mutant flies compared to wild-type controls. In particular, gene CG6364 is predicted to have uridine kinase activity. Thus, the in vivo mutation of this gene putatively disrupts the nucleotide salvage pathway, causing a decrease in bacterial replication. To further test the function of gene CG6364 in bacterial replication, we obtained cyclopentenyl cytosine (CPEC) from the National Cancer Institute. CPEC is a cytidine triphosphate (CTP) inhibitor known to deplete CTP pools in various cancers and to exhibit antiviral activity. Consequently, it inhibits de novo nucleotide synthesis, but doesn’t affect the nucleotide salvage pathway. When S2 cells were treated with CPEC and infected with Ehrlichia, an increase in bacterial replication was confirmed by qRT-PCR. Furthermore, addition of cytosine to S2 cells also resulted in increased bacterial replication. Therefore the nucleotide salvage pathway through cytidine appears necessary for bacterial replication. Our approach has successfully identified host genes that contribute to the pathogenicity of E. chaffeensis in Drosophila.
APA, Harvard, Vancouver, ISO, and other styles
5

Arteaga, Blanco Luis Andres. "Differential cellular immune response of hemocyte of Galleria mellonella larvae against Actinobacillus pleuropneumoniae strains." Universidade Federal de Viçosa, 2016. http://www.locus.ufv.br/handle/123456789/9267.

Full text
Abstract:
Submitted by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2016-12-23T12:26:14Z No. of bitstreams: 1 texto completo.pdf: 716349 bytes, checksum: 491af184849bdcb2477fa46e3081a75f (MD5)
Made available in DSpace on 2016-12-23T12:26:14Z (GMT). No. of bitstreams: 1 texto completo.pdf: 716349 bytes, checksum: 491af184849bdcb2477fa46e3081a75f (MD5) Previous issue date: 2016-07-15
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Os insetos respondem à infecção através da montagem de reações imunes do tipo celular e humoral. Os reguladores primários dessas respostas são células chamadas hemócitos, os quais medeiam importantes respostas celulares, incluindo a fagocitose, encapsulamento, nodulação, e também segregam fatores humorais, tais como opsoninas, fatores de melanização e peptídeos antimicrobianos. Os hemócitos circulam ao longo da hemocele (cavidade corporal do inseto) pelo fluxo rápido da hemolinfa (sangue), além disso, partes desses hemócitos também existem como células sésseis que estão associados aos tecidos. As larvas de Galleria mellonella são uma alternativa viável para os modelos tradicionais dos mamíferos para estudar a eficácia de drogas antimicrobianas e a patogênese de microrganismos in vivo. No entanto, apesar da sua importância como um modelo de infecção, aspectos biológicos sobre as células do sistema imunológico, tais como a densidade e dinâmica dos hemócitos das larvas são mal compreendidos. No presente trabalho, investigamos a resposta imune celular dos hemócitos circulantes das larvas de G. mellonella contra diferentes cepas da bactéria Gram-negativa Actinobacillus pleuropneumoniae: baixa virulência (780), alta virulência (1022), e cepas de referência do sorotipo 8 (R8). Os hemócitos foram classificados com base no seu tamanho, morfologia, coloração e seus papeis na resposta imune, incluindo cinco tipos: prohemócitos, plasmatócitos, granulócitos, esferulócitos, e oenocitóides. Contagem total de hemócitos, contagem diferencial de hemócitos, atividade dos fagolisossomos, resposta autofágica, viabilidade celular, e a ativação da caspase-3 (como indicador de apoptose) foram determinados em hemócitos circulantes provenientes de larvas desafiadas e controle. Demostramos pela primeira vez no modelo de G. mellonella que os plasmatócitos e granulócitos ativam suas respostas autofágicas através da formação dos autofagossomos após o contato com A. pleuropneumoniae. Além disso, nossos dados demonstram que a imunidade celular do presente modelo de infecção muda dependendo do grau de virulência das cepas bacterianas.
Insects respond to infection by mounting cellular and humoral immune reactions. The primary regulators of these immune responses are cells called hemocytes, which mediate important cellular immune responses including phagocytosis, encapsulation, nodulation and also secrete immune factors such as opsonins, melanization factors and antimicrobial peptides. Hemocytes circulate through the hemocoel (body cavity) by the swift flow of hemolymph (blood), and part of these hemocytes population are sessile and are attached to tissues. Larvae of Galleria mellonella is a widely used factitious host as a viable alternative to traditional mammalian models to study the efficacy of antimicrobial drugs and the microbial pathogenesis in vivo. However, despite their importance as an infection model, biological aspects about the immune cells, such as density and hemocyte dynamic of larvae are poorly understood. In the present study, we investigated the cellular immune response of hemocytes from G. mellonella larvae against three strains of the gram-negative bacterium Actinobacillus pleuropneumoniae: low virulent (780), high virulent (1022), and the serotype 8 reference strain (R8). Five types of larval hemocytes, prohemocytes, plasmatocytes, granulocytes, oenocytoids, and spherulocytes, were distinguished according to size, morphology, detection by molecular probes, dye-staining properties, and their role in the immune response. Total hemocyte count, differential hemocyte count, lysosome activity, autophagic response, cell viability, and caspase-3 activation were determined in circulating hemocytes of naïve and infected larvae. Granulocytes and plasmatocytes were the major hemocyte types involved in the cellular defense against A. pleuropneumoniae; these hemocytes activated phagolysosome activities associated with an autophagic response against the bacteria. Moreover, our results showed that apoptosis in circulating hemocytes after exposure to virulent bacterial strains was related to an excessive autophagic cell death response induced by stress and subsequent caspase-3 activation.
APA, Harvard, Vancouver, ISO, and other styles
6

Krzemien, Joanna. "Control of larval hematopoiesis in Drosophila ; microenvironment, precursors and cell lineage." Toulouse 3, 2008. http://www.theses.fr/2008TOU30206.

Full text
Abstract:
L'hématopoiése larvaire de la drosophile a lieu au sein d'un organe spécialisé, la glande de la lymphe (LG) qui produit des plasmatocytes spécialisés dans la phagocytose et des cellules à cristaux nécessaires à la mélanisation des corps étrangers (4). La LG est aussi à l'origine des lamellocytes nécessaires à l'encapsulation de gros corps étrangers et qui se différencient en réponse à des challenges immuns particuliers tels que le parasitisme par des hyménoptères. En 2004, notre laboratoire a montré que Collier (Col), l'orthologue du facteur de transcription mammifère Early B-Cell Factor est exprimé et requis dans un petit groupe de cellules spécialisées de la LG, le PSC, pour la différenciation des lamellocytes en réponse au parasitisme. Outre le PSC, la LG est organisée en deux zones distinctes : une zone médullaire (MZ) contenant les cellules précurseurs et une zone corticale (CZ) formée des cellules différenciées ayant quitté la MZ. Au cours de la première partie de ma thèse, j'ai étudié le contrôle de l'hématopoièse larvaire et montré que le PSC régulait de manière cellulaire non autonome, l'activité de la signalisation JAK/STAT dans les cellules précurseurs, empêchant ainsi leur différenciation prématurée et préservant leur capacité à se différencier en lamellocytes. Le rôle clef du PSC dans le maintien d'un pool de progéniteurs l'apparente à la niche hématopoiétique des vertébrés, un micro-environnement cellulaire requis pour le maintien de cellules souches tout au long de la vie adulte. Ceci posait la question de l'existence de cellules souches hématopoiètiques chez la drosophile, une question que j'ai abordée dans la deuxième partie de ma thèse. L'utilisation de marqueurs de cellules souches, de marqueurs de division asymétrique, ou la recherche de cellules quiescentes ne m'ont pas permis d'identifier des cellule souches dans la LG. J'ai alors mis en oeuvre des expériences de lignage cellulaire et montré que les pro-hémocytes acquièrent un destin plasmatocyte ou cellule à cristaux dés le premier stade larvaire, avant une phase de prolifération intense. .
The Drosophila larval hematopoietic organ, the lymph gland (LG), disperses at metamorphosis, releasing two types of hemocytes: plasmatocytes involved in phagocytosis and crystal cells necessary for encapsulation which differentiate in response to specific immune challenges, such as parasitization by wasps. Collier (Col), the Drosophila ortholog of mammalian Early B - Cell Factor, is expressed and required in a small group of cells of the LG, the PSC and in the differentiation of lamellocytes. In addition to the PSC, the LG is organised in two zones: a medullary zone (MZ) containing prohemocytes and a cortical zone (CZ) containing differentiating cells. I showed that the PSC controls the balance between the pool of prohemocytes and differentiating hemocytes. PSC cells act, in a non-cell autonomous manner, to maintain JAK/STAT signaling in prohemocytes, preventing their premature differentiation and preserving the multipotent character necessary for lamellocyte differentiation. The PSC acts a micro-environment for Drosophila hematopoietic precursors which is reminiscent of the HSC (Hematopoietic Stem Cell) niche of vertebrates. To see if there exist HSC in the LG, I looked for stem cell markers and I could't get evidence for the presence of bona fide stem cells in the LG. Using clonal analyses, I determined that hemocyte precursors become committed to either plasmatocytes or crystal cells durind the L1 larval stage, followed by a phase of intense proliferation. Finally, I obtained evidence that lamellocytes and crystal cells share a common progenitor
APA, Harvard, Vancouver, ISO, and other styles
7

Hall, Jonathon Michael. "Temporal changes in the fatty acid composition and fluidity of gill and hemocyte membranes during thermal acclimation of the sea scallop, Placopecten magellanicus." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ54894.pdf.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Liu, Haipeng. "Functional Studies of Some Immune Relevant Genes in a Crustacean." Doctoral thesis, Uppsala universitet, Jämförande fysiologi, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-9194.

Full text
Abstract:
The freshwater crayfish, Pacifastacus leniusculus, mounts a strong innate immune response against microbes such as viruses and bacteria. In this thesis, a novel RNA interference (RNAi) method mediated with histone H2A was developed and applied in crayfish hematopoietic tissue cell cultures for gene functional studies. Further, the interactions between host (crayfish) and pathogens (white spot syndrome virus and Aeromonas hydrophila, respectively) were studied using RNAi technology in live animals. An antilipopolysaccharide factor isolated from viral challenged crayfish by suppression subtractive hybridization was shown to interfere with the propagation of white spot syndrome virus both in vivo and in vitro in crayfish, suggesting an important role of this factor in antiviral defense. Besides, RNAi of phenoloxidase, a critical immune effector involved in melanization, revealed that phenoloxidase activity is necessary for crayfish immune defense against a highly pathogenic bacterial infection in crayfish. In addition, RNAi was also employed to study a marker protein gene involved in hemocyte maturation in crayfish. Taken together, these studies may provide more insights into the immune responses against pathogen invasion as well as hemocyte ontogenesis in crustaceans.
APA, Harvard, Vancouver, ISO, and other styles
9

Hart, Courtney. "THE EFFECTS OF 4-NONYLPHENOL ON THE IMMUNE RESPONSE OF THE PACIFIC OYSTER, CRASSOSTREA GIGAS, FOLLOWING BACTERIAL INFECTION (VIBRIO CAMPBELLII)." DigitalCommons@CalPoly, 2016. https://digitalcommons.calpoly.edu/theses/1609.

Full text
Abstract:
Endocrine disrupting chemicals (EDCs) are compounds that can interfere with hormone signaling pathways and are now recognized as pervasive in estuarine and marine waters. One prevalent EDC in California’s coastal waters is the xenoestrogen 4-nonylphenol (4-NP), which has been shown to impair reproduction, development, growth, and in some cases immune function of marine invertebrates. To further investigate effects of 4-NP on marine invertebrate immune function we measured total hemocyte counts (THC), relative transcript abundance of immune-relevant genes, and lysozyme activity in Pacific oysters (Crassostrea gigas) following bacterial infection. To quantify these effects we exposed oysters to dissolved phase 4-NP at high (100 μg l-1), low (2 μg l-1), or control (100 μl ethanol) concentrations for 7 days, and then experimentally infected (via injection into the adductor muscle) the oysters with the marine bacterium Vibrio campbellii. 4-NP significantly altered the effects of bacterial infection had on THC. Oysters exposed to both high and low 4-NP did not experience a bacteria-induced increase in THC, as seen in control oysters. We also determined that V. campbellii infection induced differential expression of a subset of immune-related genes tested (Cg-bigdef2, Cg-bpi1, Cg-lys1, Cg-timp) in some, but not all, tissues; 4-NP exposure altered expression patterns in two of these genes (Cg-bpi1 and Cg-tgase). Exposure to 4-NP alone also caused differential expression in some genes (Cg-bpi1, Cg-galectin1, Cg-clec2). Lastly, low levels of 4-NP significantly increased lysozyme activity 24 h post-infection. These results suggest that exposure to 4-NP can alter both cellular and humoral immune responses to bacterial infection in C. gigas.
APA, Harvard, Vancouver, ISO, and other styles
10

BORELLO, ALESSIO. "Vibrio interactions with bivalve hemocytes and analysis of the Crassostrea gigas microbiota." Doctoral thesis, Università degli studi di Genova, 2021. http://hdl.handle.net/11567/1047238.

Full text
Abstract:
My PhD project aimed at investigating the molecular mechanisms at the basis of the interaction between Vibrio bacteria and shellfish in the bivalve models Crassotrea gigas and Mytilus galloprovincialis and to study the composition and dynamics of bivalve microbiota. Previous studies suggested that persistence of entrapped bacteria inside bivalve tissues depends, at least in part, on their capacity to survive to the hemolymph bactericidal activity, that is exerted by both hemocytes and serum soluble factors. In the first part of my PhD work, hemocytes of M. galloprovincialis were challenged with different pathogenic Vibrio strains (V. aestuarianus 01/032, V. aestuarianus 02/041, V. tasmaniensis LGP32, V. harveyi VH2, V. tapetis CECT 4600 and V. coralliilyticus ATCC BAA 450) in the presence or in the absence of the extrapallial protein present in M. galloprovincialis serum (MgEP), and of the whole hemolymph serum. In addition, C. gigas hemocytes were exposed to the bivalve pathogens V. aestuarianus 01/032 and V. aestuarianus 02/041 under the same conditions to better understand molecular basis of bacteria-hemolymph interactions in oysters. We observed that MgEP promotes D- mannose sensitive adhesion to and killing by hemocytes of the bivalve pathogens V. aestuarianus 01/032, V. aestuarianus 02/041, V. tasmaniensis LGP32 and V. coralliilyticus ATCC BAA 450. In addition, in the presence of M. galloprovincialis EP protein (MgEP), C. gigas haemocytes killed V. aestuarianus 01/032 and V. aestuarianus 02/041 almost as efficiently as mussel phagocytes. These findings suggest that the different sensitivity of Vibrio strains to the antibacterial activity of oyster (susceptible to Vibrio infection) and mussel (resistant to Vibrio infection) haemolymph might partly depend on the fact that C. gigas serum lacks MgEP-like opsonins. These results may have important implications for improving bivalve depuration strategies and prevent diseases affecting bivalve production worldwide. In the second part of my thesis work, I studied the microbial communities associated to contrasting C. gigas samples collected during mortality episodes in different European sites. Real-time PCR targeting oyster pathogens (e.g. Ostreid herpesvirus 1 [OshV-1] and V. aestuarianus) and 16SrRNA gene-based microbial profiling were applied on a large number of C. gigas samples (n=525 and n=101 for qPCR and 16SrRNA gene profiling analysis, respectively) to extensively investigate the patterns and dynamics of oyster microbiota during mortality events. Comparative analysis of contrasting (e.g. infected vs not infected) C. gigas samples conducted using these methods revealed that oyster experiencing mortality outbreaks displayed signs of microbiota disruption associated with the presence of previously undetected potential pathogenic microbial species mostly belonging to genus Vibrio and Arcobacter. This represents to our knowledge, the largest study conducted so far to determine the composition and dynamics of farmed oyster microbiota.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Books on the topic "Hemocyte"

1

1928-, Gupta A. P., ed. Hemocytic and humoral immunity in arthropods. New York: Wiley, 1986.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
2

Chen, Jyun-hung. Cell activation model of hemocyte aggregation and adhesion in the California mussel, Mytilus californianus. 1992.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
3

P, Gupta A. Insect Hemocytes: Development, Forms, Functions and Techniques. Cambridge University Press, 2010.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
4

P, Gupta A. Insect Hemocytes: Development, Forms, Functions and Techniques. Cambridge University Press, 2009.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
5

P, Gupta A. Insect Hemocytes: Development, Forms, Functions and Techniques. Cambridge University Press, 2012.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
6

A Review of the Insect Immune System and Evidence for Fad-Glucose Dehydrogenase in Hemocytes of the Mosquito Aedes Aegypti. Storming Media, 1997.

Find full text
APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "Hemocyte"

1

Sierra, L. María, Erico R. Carmona, Leticia Aguado, and Ricard Marcos. "The Comet Assay in Drosophila: Neuroblast and Hemocyte Cells." In Genotoxicity and DNA Repair, 269–82. New York, NY: Springer New York, 2014. http://dx.doi.org/10.1007/978-1-4939-1068-7_15.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Inamori, K., T. Saito, D. Iwaki, T. Nagira, S. Iwanaga, F. Arisaka, and S. Kawabata. "Horseshoe Crab Hemocyte- Derived Lectin Recognizing Specific 0-Antigens of Lipopolysaccharides." In Advances in Experimental Medicine and Biology, 185–90. Boston, MA: Springer US, 2001. http://dx.doi.org/10.1007/978-1-4615-1291-2_16.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Moreira, Carolina G. A., Jennifer C. Regan, Anna Zaidman-Rémy, Antonio Jacinto, and Soren Prag. "Drosophila Hemocyte Migration: An In Vivo Assay for Directional Cell Migration." In Methods in Molecular Biology, 249–60. Totowa, NJ: Humana Press, 2011. http://dx.doi.org/10.1007/978-1-61779-207-6_17.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Xie, Xiaoyong, Kit Yue Kwan, Jinxiang Zhong, Mujiao Xie, Guoling Ye, and Yuyuan Bao. "Preliminary Characterization of Hemocyte and Immunity of Asian Horseshoe Crabs, Tachypleus tridentatus, and Carcinoscorpius rotundicauda in Captivity." In International Horseshoe Crab Conservation and Research Efforts: 2007- 2020, 161–75. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-82315-3_11.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Serrato, Lluìs Albert Matas, Alessandro Bilella, and Simon Blanchoud. "Noninvasive Intravascular Microtransfusion in Colonial Tunicates." In Methods in Molecular Biology, 399–415. New York, NY: Springer US, 2022. http://dx.doi.org/10.1007/978-1-0716-2172-1_21.

Full text
Abstract:
AbstractTunicates are a diverse group of worldwide marine filter-feeders that are vertebrates’ closest invertebrate relatives. Colonial tunicates are the only know chordates that have been shown to undergo whole-body regeneration (WBR). Botrylloides in particular can regenerate one fully functional adult from a minute fragment of their vascular system in as little as 10 days. This regenerative process relies on the proliferation of circulating stem cells, likely supported by the activity of some of the 11 identified types of hemocytes. To study and challenge WBR, it is thus important to have the capacity to isolate, analyze, and manipulate hemolymph in regenerating colonies. Here we present a microtransfusion technique that permits the collection of pure hemocytes, the quantification of their purity, their labeling, and reinjection into colonial tunicates. To exemplify our approach, we present in addition a protocol to analyze the isolated hemocytes using flow cytometry. Our approach is minimally invasive, does not induce lethality, and therefore allows repeated transfusion into exactly the same colony with minimal disruption to the process being studied.
APA, Harvard, Vancouver, ISO, and other styles
6

Parrinello, Nicolò, Matteo Cammarata, Mirella Vazzana, Vincenzo Arizza, Aiti Vizzini, and Edwin L. Cooper. "Immunological Activity of Ascidian Hemocytes." In The Biology of Ascidians, 395–401. Tokyo: Springer Japan, 2001. http://dx.doi.org/10.1007/978-4-431-66982-1_58.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Parrinello, N. "Cytotoxic Activity of Tunicate Hemocytes." In Invertebrate Immunology, 190–217. Berlin, Heidelberg: Springer Berlin Heidelberg, 1996. http://dx.doi.org/10.1007/978-3-642-79735-4_9.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Fisher, W. S. "Structure and Functions of Oyster Hemocytes." In Proceedings in Life Sciences, 25–35. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-70768-1_3.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Capinera, John L., Thomas O. Crist, John B. Heppner, Minos E. Tzanakakis, Severiano F. Gayubo, Aurélien Tartar, Pauline O. Lawrence, et al. "Hemocytes of Insects: Their Morphology and Function." In Encyclopedia of Entomology, 1787–90. Dordrecht: Springer Netherlands, 2008. http://dx.doi.org/10.1007/978-1-4020-6359-6_1302.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Lehrer, Robert I., In Hee Lee, Lorenzo Menzel, Alan Waring, and Chengquan Zhao. "Clavanins and Styelins, α-Helical Antimicrobial Peptides from The Hemocytes of Styela clava." In Advances in Experimental Medicine and Biology, 71–76. Boston, MA: Springer US, 2001. http://dx.doi.org/10.1007/978-1-4615-1291-2_7.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Hemocyte"

1

Tokmakova, A. S., E. E. Prokhorova, M. K. Serebryakova, and G. L. Ataev. "FUNCTIONAL ACTIVITY OF HEMOCYTES OF PULMONARY MOLLUSCS." In V International Scientific Conference CONCEPTUAL AND APPLIED ASPECTS OF INVERTEBRATE SCIENTIFIC RESEARCH AND BIOLOGICAL EDUCATION. Tomsk State University Press, 2020. http://dx.doi.org/10.17223/978-5-94621-931-0-2020-38.

Full text
Abstract:
Hemocytes, the cell of the hemolymph, play a key role in the immune response of pulmonate molluscs to various pathogens including trematode infection. The number of hemocytes is known to increase after immunization but the mechanism of their multiplication remains debatable. In this work we studied the functional and proliferative activity of hemocytes in two species of pulmonate molluscs: Biomphalaria glabrata, Planorbarius corneus. ImageStream technique was used for the study of the hemocyte populations of these molluscan species for the first time. The hemocytes of all the studied species were represented by two main types, granular cells and hyalinocytes. Microscopic and flow-cytometric study of the hemocytes with the use of EdU revealed some EdU-positive cells. However, the analysis of the cell cycle of the hemocytes showed that the amount of DNA in these cells was not increased.
APA, Harvard, Vancouver, ISO, and other styles
2

polyphemus, Limulus, T. Muta, T. Miyata, F. Tokunaga, T. Nakamura, and S. Iwanaga. "PRIMARY STRUCTURE OF ANTI-LIPOPOLYSACCHARIDE FACTOR ISOLATED FROM AMERICAN HORSESHOE CRAB." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644608.

Full text
Abstract:
In 1982, a protein component that inhibits the limulus coagulation cascade was found in the hemocyte lysates from Japanese and American horseshoe crabs and named anti-lipopolysaccharide (LPS) factor. This protein specifically inhibited the LPS-mediated activation of limulus factor C and had a strong anti-bacterial effect on the growth of Gram-negative R-type bacteria. Moreover, it had a hemolytic activity on the red blood cells sensitized with LPS.In the present study, the complete amino acid sequence of anti-LPS factor purified from the Limulus (L) polyphemus hemocytes was determined by characterization of the NH2-terminal sequence and the peptides generated after digestion of the protein with lysyl endopeptidase, clostripain, and Staphylococcus aureus V8 protease. Upon sequencing the peptides by the automated Edman method, the following primary structure was obtained:During the sequence analysis, two species of the protein, which differed from each other at one locus, were found and characterized. L. polyphemus anti-LPS factor was a basic protein consisting of a single polypeptide chain of 101 residues and a calculated molecular weight of 11,786 or 11,800. The hydrophobic NH2-terminal sequence and positive charges found in the disulfide loop yielded a typical amphipathic character of this protein. Moreover, L. polyphemus anti-LPS factor showed 83% sequence identity with the Tachypleus tridentatus protein (J. Aketagawa, et al. (1986) J. Biol. Chem. 261, 7357-7365), and the sequence similar to that observed in the EF-hand structure was found to contain in the COOH-terminal portions of these proteins, although its function is unknown.
APA, Harvard, Vancouver, ISO, and other styles
3

Uragoh, K., K. Sueishi, T. Nakamura, S. Iwanaga, and K. Tanaka. "IMMUNOHISTOCHEMICAL STUDIES ON THE LOCALIZATION OF ENDOTOXIN (LPS) IN VIVO BY USING HORSESHOE CRAB FACTOR C." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644250.

Full text
Abstract:
The localization of LPS in vivo was studied with immunohistochemical method using Ig G against Factor C, which was extracted from hemocyte lysate of horseshoe crab and had the specific affinity to LPS. Organs of rats and guinea pigs were light microscopically investigated at different times after intravenous injection of LPS (E.coli; 0111:B4,026:B6 and salmonella typhosa). Tissues were fixed with buffered formalin and then embedded in paraffin. Deparaffinized sections were incubated with Factor C (lpg/ml) for 1 hr, and then with anti-Factor C Ig G for 1 hr, followed by immunoperoxidase method. The immunohistochemical specificity was examined by absorption of Factor C with LPS, binding competition between Factor C and anti-LPS factor which was extracted from hemocyte lysate of horseshoe crab as well as Factor C or using normal animal tissues and normal Ig G. The immunohistochemical specificity was revealed by these examinations. Immunohistochemically, LPS located predominantly in liver and lung, especially in Kupffer cells and infiltrating monocytes and neutrophils, and aggregated platelets since 5 minutes after intravenous injection of LPS. On the endothelial surface of hepatic sinusoids, glomeruli and pulmonary vessels, LPS was also detected in early period. In addition, LPS was also shown within adrenocortical parenchymal cells, particularly of fascicular zone, later. LPS was not detected 3 days after injection of LPS in liver and lung, but remained during 3 days of observation in adrenocortical parenchymal cells. The present studies revealed that Factor C could be available for immunohistochemical demonstration of LPS in vivo, and reticuloendothelial system, macrophages/monocytes and neutrophils were important as the scavenger cells of LPS and might play a significant role on the development of multiorgan failure in endotoxemia.
APA, Harvard, Vancouver, ISO, and other styles
4

Smith, Ryan C. "Mosquito hemocytes mediate late-phase immune responses that limitPlasmodiumoocyst survival." In 2016 International Congress of Entomology. Entomological Society of America, 2016. http://dx.doi.org/10.1603/ice.2016.92448.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Kato, Yoko. "The Role of Protein as a Deformation Controller in Cellulose Tissue." In ASME 2012 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/imece2012-89313.

Full text
Abstract:
The tunic of Halocynthia roretzi is composed of cellulose Iβ, mostly in crystalline form. It was recently revealed that the tunic can actively deform in response to mechanical stimuli and acetylcholine and that the tunic has F-actin, elastic fibers, acetylcholinesterase, and neurofilaments, which are involved in this process. Most of the hemocytes in the tunic secrete an enzyme whose substrate is the same as that of α-chymotrypsin; however, the enzyme’s role has not yet been determined. In this study, it was hypothesized that the enzyme hydrolyzes the protein in the tunic to induce tunic deformation. The results show that administration of α-chymotrypsin results in deformation of the tunic in an inward direction. Tunic deformation can be induced by the secretion of hemocytes due to greater hydrolysis of protein in the inner rather than outer regions. The deformation pattern is the same as that induced by both mechanical stimuli and acetylcholine. Moreover, stimulation with an electrical field (3.4 × 102 V/m), which is too weak to deform cellulose, still causes tunic deformation, indicating involvement of the nervous system. These characteristics will be helpful for the design of an active composite material containing cellulose.
APA, Harvard, Vancouver, ISO, and other styles
6

Huang, Jia. "Roles of biogenic amine receptors in insect hemocytes to regulate cellular immunity." In 2016 International Congress of Entomology. Entomological Society of America, 2016. http://dx.doi.org/10.1603/ice.2016.93036.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Prisnyi, A. A., and E. A. Grebtsova. "Morphological and functional status of hemocytes in species of the order Blattodea." In PROCEEDINGS OF THE II INTERNATIONAL CONFERENCE ON ADVANCES IN MATERIALS, SYSTEMS AND TECHNOLOGIES: (CAMSTech-II 2021). AIP Publishing, 2022. http://dx.doi.org/10.1063/5.0092439.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Yung-Chiang Chung, Yen-Wen Hu, Tsong-Long Hwang, Po-Wen Chen, and Fong-Jian Sie. "Acting force comparison of microbeads and hemocytes in microchannel using optical tweezers system." In 2009 4th IEEE International Conference on Nano/Micro Engineered and Molecular Systems. IEEE, 2009. http://dx.doi.org/10.1109/nems.2009.5068750.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Saltykova, E. S., L. R. Gaifullina, A. V. Poskryakov, and A. G. Nikolenko. "INFLUENCE OF IMIDACLOPRIDE ON THE IMMUNITY OF HONEY BEES (APIS MELLIFERA L.)." In V International Scientific Conference CONCEPTUAL AND APPLIED ASPECTS OF INVERTEBRATE SCIENTIFIC RESEARCH AND BIOLOGICAL EDUCATION. Tomsk State University Press, 2020. http://dx.doi.org/10.17223/978-5-94621-931-0-2020-58.

Full text
Abstract:
The effect of the neonicotinoid, which is the most toxic for bees, on the components of the individual immunity of Apis mellifera L. workers, was studied. It was shown that a non-lethal dose of imidacloprid caused pathological changes in the intestine and fat body cells, the insect's reaction to its own decaying cells and tissues, aggregation, adhesion and lysis of granulocytes that removes a significant proportion of protective cells from the bloodstream, the generation of reactive oxygen species under the inhibition of phenol oxidase activity in hemocytes.
APA, Harvard, Vancouver, ISO, and other styles
10

Hu, Jian. "Glycoprotein hemomucin protects embryos of polyembryonic parasitoidMacrocentrus cingulumto evade the encapsulation of host hemocytes." In 2016 International Congress of Entomology. Entomological Society of America, 2016. http://dx.doi.org/10.1603/ice.2016.94066.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "Hemocyte"

1

Loy, J. Dustin, and D. L. Hank Harris. Evaluation of in vivo Hemocyte Phagocytosis of Microsphere Beads in Litopenaeus vannamei Utilizing Flow Cytometry Following Administration of Bacterial Lipopolysaccharides. Ames (Iowa): Iowa State University, January 2010. http://dx.doi.org/10.31274/ans_air-180814-1257.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Chejanovsky, Nor, and Bruce A. Webb. Potentiation of pest control by insect immunosuppression. United States Department of Agriculture, July 2004. http://dx.doi.org/10.32747/2004.7587236.bard.

Full text
Abstract:
Our original aims were to elucidate the mechanisms through which the immunosuppressive insect virus, the Campoletis sonorensis polydnavirus (CsV) promotes replication of a well-characterized pathogenic virus, the Autographa californica multiple nucleopolyhedrovirus (AcMNPV) in hosts that are mildly or non-permissive to virus replication. According to the BARD panels criticism we modified our short-term goals (see below). Thus, in this feasibility study (one-year funding) we aimed to show that: 1. S. littoralis larvae mount an immune response against a baculovirus infection. 2. Immunosuppression of an insect pest improves the ability of a viral pathogen (a baculovirus) to infect the pest. 3. S. littoralis cells constitute an efficient tool to study some aspects of the anti- viral immune response. We achieved the above objectives by: 1. Finding melanized viral foci upon following the baculoviral infection in S . littoralis larvae infected with a polyhedra - positive AcMNPV recombinant that expressed the GFP gene under the control of the Drosophila heat shock promoter. 2. Studying the effect of AcMNPV-infection in S . littoralis immunosuppressed by parasitation with the Braconidae wasp Chelonus inanitus that bears the CiV polydna virus, that resulted in higher susceptibility of S. littoralis to AcMNPV- infection. 3. Proving that S. littoralis hemocytes resist AcMNPV -infection. 4. Defining SL2 as a granulocyte-like cell line and demonstrating that as littoralis hemocytic cell line undergoes apoptosis upon AcMNPV -infection. 5. Showing that some of the recombinant AcMNPV expressing the immuno-suppressive polydna virus CsV- vankyrin genes inhibit baculoviral-induced lysis of SL2 cells. This information paves the way to elucidate the mechanisms through which the immuno- suppressive polydna insect viruses promote replication of pathogenic baculoviruses in lepidopteran hosts that are mildly or non-permissive to virus- replication by: - Assessing the extent to which and the mechanisms whereby the immunosuppressive viruses, CiV and CsV or their genes enhance AcMNPV replication in polydnavirus- immunosuppressed H. zea and S. littoralis insects and S. littoralis cells. - Identifying CiV and CsV genes involved in the above immunosuppression (e.g. inhibiting cellular encapsulation and disrupting humoral immunity). This study will provide insight to the molecular mechanisms of viral pathogenesis and improve our understanding of insect immunity. This knowledge is of fundamental importance to controlling insect vectored diseases of humans, animals and plants and essential to developing novel means for pest control (including baculoviruses) that strategically weaken insect defenses to improve pathogen (i.e. biocontrol agent) infection and virulence.
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Hemocyte' for particular source types:
Journal articles Dissertations / Theses
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography