A rhamnose-binding lectin from sea bass (Dicentrarchus labrax) plasma agglutinates and opsonizes pathogenic bacteria

Abstract The discovery of rhamnose-binding lectins (RBLs) in teleost fish eggs led to the identification of a novel lectin family characterized by a unique sequence motif and a structural fold, and initially proposed to modulate fertilization. Further studies of the RBL tissue localization and gene organization were also suggestive of role(s) in innate immunity. Here we describe the purification, and biochemical and functional characterization of a novel RBL (DlRBL) from sea bass (Dicentrarchus labrax) serum. The purified DlRBL had electrophoretic mobilities corresponding to 24 kDa and 100 kDa under reducing and non-reducing conditions, respectively, suggesting that in plasma the DlRBL is p…

Haemolytic activity and characterization of nematocyst venom fromPelagia noctiluca(Cnidaria: Scyphozoa)

We investigated the haemolytic capacity of the crude venom extracted from isolated nematocysts of Pelagia noctiluca (Cnidaria: Scyphozoa), and evidenced the proteic fractions responsible for this activity. The nematocyst venom was used at various concentrations to evaluate the haemolytic activity and the lysosomal membrane stability of red blood cells of two teleostean species treated with the extract. The nematocyst extract was assayed against erythrocytes of the two teleostean species living in different environments, Carassius auratus as a common freshwater species, and Liza aurata as a representative of seawater species. Experiments on the haemolytic activity of P. noctiluca in the pres…

Purification and characterization of an f-type lectin from small-spotted catshark (Scyliorhinus canicula)serum

Inflammatory-like reaction following bacterial injection and antimicrobial peptide isolation from Anemonia sulcata (Cnidaria)

Isolation and characterization of a fish F-type lectin from gilt head bream (Sparus aurata) serum.

A novel fucose-binding lectin, designated SauFBP32, was purified by affinity chromatography on fucose-agarose, from the serum of the gilt head bream Sparus aurata. Electrophoretic mobility of the subunit revealed apparent molecular weights of 35 and 30 kDa under reducing and non-reducing conditions, respectively. Size exclusion analysis suggests that the native lectin is a monomer under the selected experimental conditions. Agglutinating activity towards rabbit erythrocytes was not significantly modified by addition of calcium or EDTA; activity was optimal at 37 degrees C, retained partial activity by treatment at 70 degrees C, and was fully inactivated at 90 degrees C. On western blot anal…

Antimicrobial response in Anemonia sulcata (Cnidaria)

Isolamento, caratterizzazione e distribuzione cellulare di una neurotossina ad attività litica di Actinia equina (Anthozoa, Cnidaria

Attività biologica e caratterizzazione molecolare di un peptide neurotossico ad attività litica di Actinia equina (Anthozoa, Cnidaria)

Effetti dell'esposizione in vitro al cloruro di metilmercurio Sulle risposte immunitarie di Dicentrarchus labrax.

This study shows that high methylmercury concentrations are cytotoxic for Dicentrarchus labrax leucocytes, whereas subletal concentrations affect leucocyte phagocytosis and cells morphology in a dose dependent fashion. Although the serum hemoagglutinating activity was not inhibited by the metal, the activity of purified serum F-lectin fraction and mucus was significantly decreased by relevant methylmercury concentrations.

Lectine sieriche di "tipo F" nell'immunità innata dei pesci: aspetti molecolari e funzionali.

Purification and characterization of D-galactose binding lectin involved in the inflammatory response in Ciona intestinalis

Serum lectins in fish innate immunity: molecular and functional aspects

Fucose-binding lectins (FBL) are present in tissues and fluids from invertebrates and vertebrates. The lectin repertoires in teleost fish are highly diversified and recently has been described the structure of the fucose-binding agglutinin that revealed a novel lectin fold (the “F-type” eel (Anguilla anguilla) fold), which shared a unique fucose-binding sequence motif contained both in carbohydrate-binding proteins and unrelated proteins. In this report, we describe serum FBL from sea bass Dicentrarchus labrax and sea bream Sparus aurata. These lectins were purified, characterized, cloned and sequenced. Studies on structural aspects, biological activity, tissue distribution as well as ontog…

Purificazione di una lectina calcio dipendente dal muco di Sabella spallanzanii (Polychaeta: Sabellidae)

From Cnidarian immunobiology to cultural heritage applications

The study of cnidarians immunity, as model systems of metazoans, lead additional informations on the first steps of the immunity evolution. The functions of the genes and cellular pathways in higher vertebrates are conserved during the evolution of metazoans, as shown by the discovery of homologues in cnidarians. These basal metazoans in fact, are far from "simples" in the range of methods at their disposal to deal with potential prey but also invading microbes and pathogens. They can give informations about the invertebrates innate immune repertoire. We investigated the immunobiology starting from the inflammatory response in Anemonia sulcata (Cnidaria: Anthozoa) following injection of sub…

Biological activity, tissue distribution and preliminary moleular characterization of a serum fucolectin from the sea bass (Dicentrarchus labrax)

F-type lectin from the sea bass (Dicentrarchus labrax): purification, cDNA cloning, tissue expression and localization, and opsonic activity.

Recently described biochemical and structural aspects of fucose-binding lectins from the European eel (Anguilla anguilla) and striped bass (Morone saxatilis) led to the identification of a novel lectin family ("F-type" lectins) characterized by a unique sequence motif and a characteristic structural fold. The F-type fold is shared not only with other members of this lectin family, but also with apparently unrelated proteins ranging from prokaryotes to vertebrates. Here we describe the purification, biochemical and molecular properties, and the opsonic activity of an F-type lectin (DlFBL) isolated from sea bass (Dicentrarchus labrax) serum. DlFBL exhibits two tandemly arranged carbohydrate-r…

Localizzazione di una lectina di “tipo F” nell’adulto e nell’ontogenesi di Dicentrarchus labrax

The purification, cloning, sequencing, molecular properties and expression of a fucose-binding lectin from the serum of Dicentrarchus labrax (DlFBL) have been previously reported. We now describe the distribution and expression of DlFBL during fish ontogeny. Immunohistochemistry and in situ hybridization assays were carried out at various developmental stages (from 10 days posthatching larvae to juveniles). Another fucose-binding lectin, similar to DlFBL in biochemical, immunochemical and agglutinating properties, was extracted and purified from eggs and appeared to be localized in the embryo yolk sack residual. DlFBL was found in columnar and goblet cells of the intestinal epithelium of la…

Effetti tossici del metilmercurio sulle risposte immunitarie dell'ascidia Styela plicata

specific inflammatory response of Anemonia sulcata (cnidaria) after bacterial injection cause tissue rejection and enzymatic activity alteration

The evolution of multicellular organisms was marked by adaptation to protect against pathogens. The mechanisms for discriminating the ''self'' from ''non-self” have evolved into a long history of cellular and molecular strategies from damage repair to the co-evolution of host-pathogen interaction. The phylum of Cnidaria is one of the first branches in the tree of animal life to provide crucial insights on the evolution of immunity. Sea anemones (Anthozoa, Cnidaria) are benthic sessile species able to maintain the integrity of the tissues and allorecognition in colonial forms and to differentiate between symbionts and pathogenic intruders. We investigated the inflammatory response in sea ane…

In vitro effects of methylmercury on ascidian (Styela plicata) immunocyte responses

This study shows that high methylmercury concentrations are cytotoxic for Styela plicata hemocytes, whereas sublethal concentrations affect immunocyte responses. Moreover, hemocytes exposed to the xenobiotic present a significantly enhanced phenoloxidase activity as revealed in the hemocyte lysate supernatant compared with the control. Although the cytotoxic activity of S. plicata hemocytes toward rabbit erythrocytes is a PO-dependent cell-target reaction due to quinone products, it was significantly decreased by suitable methylmercury concentrations in the medium. The same xenobiotic concentrations decreased the hemocyte phagocytic activity toward yeast. In both the responses cell-target c…

Attività biologica, distribuzione tissutale e caratterizzazione molecolare della fucolectina sierica di spigola (Dicentrarchus labrax).

Characterization of cellular and molecular responses of Actinia equina (Linnaeus, 1758)

Aspetti filogenetici della nuova famiglia di lectine "di tipo F" nei Pesci.

Reazione infiammatoria ed isolamento di un peptide antimicrobico da Anemonia sulcata (Cnidaria)

Sea bass Dicentrarchus labrax (L.) bacterial infection and confinement stress acts on F-type lectin (DlFBL) serum modulation

The F-lectin, a fucose-binding protein found from invertebrates to ectothermic vertebrates, is the last lectin family to be discovered. Here, we describe effects of two different types of stressors, bacterial infection and confinement stress, on the modulation of European sea bass Dicentrarchus labrax (L.) F-lectin (DlFBL), a well-characterized serum opsonin, using a specific antibody. The infection of the Vibrio alginolyticus bacterial strain increased the total haemagglutinating activity during the 16-day testing period. The DlFBL value showed an upward regulation on the first, second and last days and underwent a slight downward regulation 4 days post-challenge. In contrast, the effect o…

Primary structure and opsonic activity of an F-lectin from serum of the gilt head breamSparus aurata(Pisces, Sparidae)

Abstract The recently described fucose-binding agglutinin from the European eel revealed a novel lectin fold (the ‘F-type’ fold) that is shared with other carbohydrate-binding proteins and proteins from prokaryotes to vertebrates clustered under the newly established F-type lectin (FTL) family. We previously reported the purification and biochemical characterization of a fucose-binding protein (FBP) isolated from serum of the gilt head bream (Sparus aurata, SauFBP). In the present article, the complete coding sequence of SauFBP revealed that it is a member of the FTL family, consisting of two tandem carbohydrate recognition domains (CRD) that display the F-type sequence motif. In vitro opso…

Modificazioni indotte dal metilmercurio sugli emociti dell’ascidia Styela plicata

Comparative analysis of fucose binding lectins isolated and characterized from different teleost species, and distribution of a F-Lectin during Dicentrarchus labrax ontogenesis

Specific inflammatory response of Anemonia sulcata (Cnidaria) after bacterial injection causes tissue reaction and enzymatic activity alteration

The evolution of multicellular organisms was marked by adaptations to protect against pathogens. The mechanisms for discriminating the ’’self’’ from ’’non-self” have evolved into a long history of cellular and molecular strategies, from damage repair to the co-evolution of host-pathogen interactions. We investigated the inflammatory response in Anemonia sulcata (Cnidaria: Anthozoa) following injection of substances that varied in type and dimension, and observed clear, strong and specific reactions, especially after injection of Escherichia coli and Vibrio alginolyticus. Moreover, we analyzed enzymatic activity of protease, phosphatase and esterase, showing how the injection of different ba…

Purification and molecular characterization of the rhamnose binding lectin from sea bass (Dicentrarchus labrax) that agglutinate Gram positive and negative bacteria

A serum fucose-binding lectin (D1FBL) from adult Didentrarchus labrax is expressed in larva and juvenile tissue and contained in eggs

The purification, cloning, sequencing, molecular properties and expression of a fucose-binding lectin from the serum of Dicentrarchus labrax (DlFBL) have been previously reported. We now describe the distribution and expression of DlFBL during fish ontogeny. Immunohistochemistry and in situ hybridization assays were carried out at various developmental stages (from 10 days posthatching larvae to juveniles). Another fucose-binding lectin, similar to DlFBL in biochemical, immunochemical and agglutinating properties, was extracted and purified from eggs and appeared to be localized in the embryo yolk sack residual. DlFBL was found in columnar and goblet cells of the intestinal epithelium of la…

Primary structure and opsonic activity of an F-lectin from serum of the gilt head bream Sparus aurata (Pisces, Sparidae)