1,720,979 research outputs found
EVOLUTION, ADAPTATION AND IMMUNE FUNCTIONS OF FISH LECTINS
No full textFish are equipped with a complex lectin repertoire that,
like mammals, are involved almost all the
immune reactions.
Carbohydrate 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. In fish, C, F types galectins, Rhamnose-bind-
ing lectin (RBL) and pentraxin have been identified in both car-
tilaginous and bony fish.
In addition, selectins and other genes
have been found in the currently available fish
genomes. On the basis of our results about F-type and RBL
lectins 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 and RBL; RBL and FTL have been identified in the
eggs and embryos but they are also present in the serum. The
characterization indicates that 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; Therefore, in order to
identify trends linked to cold adaptation in
antarctic fish, we try, to compare Perciformes and the Antartic fish
Trematomus bernacchii F lectins propertie
Invertebrate Models in Innate Immunity and Tissue Remodeling Research
Full text linkThe aim of this Special Issue is to highlight the close functional and highly conserved link between innate immunity, homeostasis maintenance, inflammation, tissue remodeling and regeneration [...
Inflammation events occurring upon bacterial infection in Mytilus galloprovincialis
Full text linkBivalves, and in particular the Mediterranean Mytilus galloprovincialis are important sources of food in several countries in the world. Because of that, mussels farming has a strong economic impact. Due to their status as sessile and filter-feeding animals, bivalves accumulate in their tissues environmental pollutants and a larger amount of microorganisms and between these, a multitude of infective bacteria for higher vertebrates and humans, such as Vibrio species. Several immunological responses of M. galloprovincialis were investigated and described after Vibrio infection both, in vitro and in vivo conditions, such as hemocytes count and different cellular subpopulations. Particularly, intracellular signaling pathways are activated to trigger the synthesis of antimicrobial effectors Here, were investigated the modulation of immunological cellular markers of the Mediterranean bivalve M. galloprovincialis in response to in vivo exposure with Vibrio splendidus. The activation of inflammatory cascade was examined through immunolabeling with antibodies involved in the pathway: Toll-like receptors 4 (TLR4), myeloid differentiation factor 88 (MYD88), Allograft inflammatory factor-1 (AIF1) and ribonucleases RNASET2 (T2 family), that trigger the recruitment and activation of macrophages in vertebrates. Results confirmed the activation of TRL4 during bacterial infection and MYD88 adapter suggesting a role in recognition and intracellular signaling. Moreover, Gram-negative bacteria determine the recruitment by the ribonuclease RNASET2 of haemocytes and a huge migration of AIF-1+ cells. This approach is suitable to understand the molecular defense mechanisms in invertebrates during the exposure to possible pathogens, also in order to develop new technics and tools to evaluate mussel immunity response used in aquaculture to prevent mass mortality of these mollusks, economic loss and potential risks for consumers of seafood
METHYLMERCURY EFFECTS ON Mytilus galloprovincialis HAEMOCYTES ACTIVITY
No full textBivalves, filter-feeding organisms, due to their wide distri-bution, are used by many countries in biomonitoring, particu-larly in the assessment of xenobiotics in the marine ecosystem.These sentinel organisms are able to accumulate trace metalsand other substances in their tissues. Haemocytes are effectorsof cellular immunity in bivalves and are capable of respond-ing to stressors through activities such as phagocytosis or cyto-toxicity. In order to identify cellular markers to investigate pol-lution, the effect of different concentrations of organic mercury(CH3HgCl) on the morphology and responses of Mytilus gal-loprovincialishaemocytes was studied in this work. Sublethalconcentrations of methylmercury, as evidenced by the Trypanblue exclusion test, were used to investigate its effect on mor-phology, the efficiency of phagocytosis towards yeast cells,the maintenance of the lysosomal membrane and the ability torelease cytotoxic molecules. Alterations in haemocyte viabili-ty, morphological changes and alterations in the cytoskeletonwere observed. The spreading ability, a cell morphometricparameter, was also used as an additional method. Exposureto CH3HgCl influenced the percentage and index of phagocy-tosis. Finally, cytoskeletal and morphological modificationslead to a reduction in the ability to adhere to the substrate andincorporate the target. The cytotoxic activity of M. gallo-provincialis haemocytes towards erythrocytes and the activityrevealed from lysis plaque assay has not been modified byadequate concentrations of methylmercury in the medium. Inaddition, membrane permeability could be affected bymethylmercury due to the reduced retention capacity of neu-tral red by the cells. This evidence confirms that theMediterranean mussel M. galloprovincialisis a suitable modelorganism in the study of the state of health of the marine envi-ronment and in particular for investigation of pollution causedby xenobiotics
INFLAMMATION AND TENTACLE REGENERATION RESPONSES IN ANEMONIA VIRIDIS (ANTHOZOA, CNIDARIA)
No full textResponse of Sabella spallanzanii to multiple stressors. The combined effect of infection and copper sulphate
Full text linkThe aim of this work is to study the immune responses of the polychaete Sabella spallanzanii after exposure to
copper sulphate, an immunomodulating agent in marine organisms, and the multiple stresses caused by
Escherichia coli infection, to validate the species as a model organism in marine-coastal biomonitoring programmes.
Polychaetes were housed in laboratory and divided into five experimental groups: 1. Control (no
microinjected), 2. filtered seawater + TBS injection (control of point 3), 3. filtered seawater + E. coli injection
(control of point 4), 4. CuSO4 + TBS injection (control of point 5), and 5. CuSO4 + E. coli injection. The immune
variables, esterase and alkaline phosphatase activity, cytotoxicity and detoxifying/antioxidant enzymes such as
glutathione peroxidase were evaluated in total body extracts of the animals. Moreover, toll-like receptor, allograft
inflammatory factor-1, lysozyme and haemagglutinating activity were investigated to highlight possible
interactions. Indeed, the results of this work demonstrate the immunomodulating effect of copper sulphate on
S. spallanzanii total body extracts related to oxidative stress and inflammatory markers
The entangled multi-level responses of Mytilus galloprovincialis (Lamarck, 1819) to environmental stressors as detected by an integrated approach
No full textAnthropogenic pressure adds up and interacts with the effects of climate change with a varying magnitude and
potential changes depend on species’ Life History (LH) traits, local environmental conditions and co-occurrence
of several stressors. Stressors exert negative effects on marine biota when acting as a single factor, but the effects
may be amplified when more than one stressor work in combination, producing interacting effects on biodiversity
and ecosystem functioning. The impairment of individual functional traits (FT) leads to strong rebounds
on LH traits and this may have ecological consequences. No studies actually relate FT and antioxidant enzymes to
multiple environmental stressors. In this paper we investigate the effects of food concentration, temperature and
hypoxia on metabolic traits as expressed by a proxy such as respiration rate and feeding behaviour and on
antioxidant enzymes (Catalase, Superoxide dismutase, Glutathione S-Transferase, Glutathione peroxidase) for
the bivalve Mytilus galloprovincialis. Mussels were exposed to three temperatures (12, 20 and 28 ◦C) under
normoxic (8 mg O2 l 1) and hypoxic (~2 mg O2 l 1) conditions, with varying food concentrations ranging from
0.9 to 3.5 μg of chlorophyll l 1. The results show that FTs and antioxidant enzymes were affected by temperature,
hypoxia and food availability, and outcome allowed us to emphasise that a multi-scalar integrated approach is
suitable to detect and monitor effects of anthropogenic disturbance on ecosystem functionin
Identification of CPE and GAIT elements in 3’UTR of macrophage migration inhibitory factor (MIF) involved in inflammatory response induced by LPS in Ciona robusta
No full textInnate immune responses face infectious microorganisms by inducing inflammatory responses. Multiple genes
within distinct functional categories are coordinately and temporally regulated by transcriptional ‘on’ and ‘off’
switches that account for the specificity of gene expression in response to external stimuli. Mechanisms that
control transcriptional and post-transcriptional regulation are important in coordinating the initiation and resolution
of inflammation. Macrophage migration inhibitory factor (MIF) is an important cytokine that, in Ciona
robusta, is related to inflammatory response. It is well known that in C. robusta, formerly known as Ciona intestinalis,
the pharynx is involved in the inflammatory reaction induced by lipopolysaccharide (LPS) injection in
the body wall. Using this biological system, we describe the identification of two C. robusta MIFs (CrMIF1 and
CrMIF2). The phylogenetic tree and modeling support a close relationship with vertebrate MIF family members.
CrMIF1 and CrMIF2 possess two evolutionally conserved catalytic sites: a tautomerase and an oxidoreductase
site with a conserved CXXC motif. Real-time PCR analysis shows a prompt expression induced by LPS inoculation
in CrMIF1 and a late upregulation of CrMIF2 and in silico analyses of 3’UTR show a cis-acting GAIT element and a
CPE element in 3’-UTR, which are not present in the 3’-UTR of CrMIF1, suggesting that different transcriptional
and post-transcriptional control mechanisms are involved in the regulation of gene expression of MIF during
inflammatory response in C. robusta
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