1,721,201 research outputs found
DIVERSITY OF LECTIN-SUGAR RECOGNITION SYSTEMS IN THE EVOLUTION OF FISH INNATE IMMUNITY
Full text linkCarbohydrate recognition and interactions mediated by lectins have been recognized involved in vertebrate innate immunity, not only for recognition of potential pathogens, but also acting in the agglutination, immobilization and other functional steps.
Fish are equipped with a complex lectin repertoire that, like mammals, are involved almost all the immune reactions.
On the basis of our results on the isolation, cDNA cloning, structural analysis, tissue expression and localization, and opsonic activity of F-type and RBL lectins from Dicentrarchus labrax and Sparus aurata we showed that:
lectin repertoires in fish are highly diversified and include not only representatives of the lectin families; described in mammals, but also members of lectin families described for the first time in fish species like the F type lectins;
the tissue-specific expression and localization of the diverse lectin repertoires and their molecular partners is consistent with their distinct biological roles in innate and adaptive immunity;
although some lectins may bind endogenous ligands, others bind sugars on the surface of potential pathogens; in addition to pathogen recognition and opsonization, some lectins display additional effector roles, such as regulation of immune function
Elie metchnikoff and the multidisciplinary link novelty among zoology, embryology and innate immunity
Full text linkElie Metchnikoff was a Russian scientist known as the pioneer of innate immunity. In particular, he was awarded the Nobel Prize for discovering the process of phagocytosis and its significance in the development and disease. Here, we endeavor to demonstrate the enduring fascination of his scientific research, in particular the experiment involving the first observation of a macrophage reaction in the sea star. This applies to both adult and larvae immunity studies. Recent work on sea star larval cellular immunity and adult immune systems using modern expansions of molecular and cellular techniques shows that it is a continually exciting research field that cannot just be consigned to history. Finally, aspects of human scientific roles - from the zoologist to embryological experiences to the father of innate immunity - can teach us much about the oft-neglected added value of multidisciplinary knowledge and integration in animal science research
Ciona robusta hemocyte populational dynamics and PO-dependent cytotoxic activity
No full textHemocyte populations from the ascidian Ciona robusta, separated through a Percoll discontinuous density gradient, are further characterized by May-Grünwald-Giemsa staining and a cytochemical reaction for phenoloxidase. Variability in cell density, acidophilic property and phenoloxidase activity suggest multiple hemocyte type populations, cell lineages and morphotypes that may be involved in distinct cellular responses. Therefore, unilocular refractile granulocytes, typical of this ascidian species, enriched in a fraction separated from the hemolymph show in vitro phenoloxidase-dependent cytotoxic activity against mammalian erythrocytes and a tumor cell lineage, in addition the properties listed above indicate relationships with vacuolated signet ring cells. Finally, bromo-deoxyuridine with, diamino-phenylindole fluorescent reaction and May-Grünwald-Giemsa staining show that in the hemolymph there are hyaline amoebocytes and granulocytes with potential proliferating activity. Present findings and reviewed images of previously reported inflammatory hemocytes in the tunic and pharynx allow us to speculate on theoretical outlines of hemocyte differentiation pathways
Immunity and Wound Healing: Regeneration or Repair?
No full textTissue injury triggers a highly complex and dynamic process of healing, involving
several coordinated molecular and cellular events to achieve the pre-damage
integrity and homeostasis. The response can occur in the form of regeneration
or repair. Regeneration is variable and results in full replacement of any part
of the body (in some invertebrates), complex structures (eg, limbs), internal
organs (eg, liver), or lost/damaged tissue so that the original architecture and
function are completely restored. In contrast, repair involves fibrotic reactions
leading to scar formation that often impair tissue functionality. The capacity to
perfectly regrow lost appendages or injured tissues varies widely among animal
species. It shows a general gradual loss during ontogenesis and, although the
mechanisms underlying regenerative ability have been largely investigated, the
reasons for the variable potentials remain unclear.....
Cell Death Pathways in an Unconventional Invertebrate Model
No full textProgrammed cell death (including apoptosis and autophagy-mediated cell death) is a fundamental feature of many important biological processes devoted to the maintenance of the body's homeostasis. Numerous research studies on programmed cell death included well-established invertebrate models like Drosophila melanogaster and Caenorhabditis elegans, and their contribution to the present knowledge on cell death was decisive. Despite this, several questions remain, especially in the relationships existing between the diverse modalities of cell death, asking for further experiments in different models. Here, we describe the prodeath effects and the pathways activated by the mitochondria-targeting drugs 2-deoxy-. d-ribose, sodium nitroprusside, or oligomycin A in the IPLB-LdFB cell line derived from the unconventional insect model Lymantria dispar
Evolution, adaptation and immune functions of fish F-type lectins. The novelty of FBL from Trematomus bernacchii (Boulenger, 1902)
Full text linkLectins are a protein family, present in almost all living organisms and involved in different biological pathways, such as immune responses. The Fucose Binding Lectin (FBL), constitute the latest lectin family identified and characterized in fishes. The FBL family is constituted by a large number of proteins exhibiting multiples of the F-type motif, either tandemly arrayed or in mosaic combinations with other domains. In an early step a FBL has been isolated and characterized from serum of the Antarctic fish
Trematomus bernacchii by affinity chromatography on fucose-agarose column. A clear Bacterial agglutinating activity (BA) towards different bacteria strains (Escherichia coli, Kokuria rhizophyla and Bacillus subtilis) and Hemagglutinating activity (HA) toward rabbit erythrocytes was induced from the serum as well from the purified protein and thus confirm its involvement in host pathogen interactions. In SDS-PAGE analysis, the FBL exhibited an apparent molecular weight of 30 kDa. This data is confirmed from the sequence of the F lectin recognised on the T. bernacchii transcriptome. The sequence shows a similar and coherent structure with a supposed Mw 32.16 kDa and an isoelectropoint of 5.21. Furthermore, sequencing the N-terminus confirmed the identity of the sequence runned on SDS PAGE and blotted on PVDF membrane. The HA activity was analyzed at different temperatures and it was maintained also at the physiological living low temperatures of this fish habitat (close to 0 °C). Therefore, in order to identify trends linked to cold adaptation in Antarctic fish, we present our hypothesis on the conformational change determined by the aminoacidic substitutions respect the others fish fucolectins living in warmer water on the light of the general phylogenetic scenario including the new preliminary data on sharks FB
Sabella spallanzanii mucus contain a galactose-binding lectin able to agglutinate bacteria. Purification and characterization
Full text linkLectins are present in almost all living organisms and are involved in several biological processes, including immune responses. In the present study, a calcium dependent galactose-binding lectin exhibiting an apparent MW of 43 kDa has been characterized and purified from the mucus of the polychaete Sabella spallanzanii by using both affinity chromatography and high-pressure liquid chromatographic methods. Its agglutinating activity towards rabbit erythrocytes was significantly modified by the addition of calcium or EDTA. The activity was optimal at temperature values comprised between 4 and 18 °C, maintain a 50% of activity between 20 and 37 °C, was significant deleted after exposure at 50 °C, and was depleted at 90 °C. The S. spallanzanii Galactose-Binding Lectin (SsGBL) was able to agglutinate bacteria and to preferentially recognize Gram-negative bacteria. The strongest agglutinating activity was observed towards Vibrio alginolyticus and Escherichia coli, by contrast mucus agglutinated in a lesser extent both Aeromonas hydrophyla and the Gram-positive Micrococcus lysodeikticus thus suggesting its involvement in host pathogen interactions
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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