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F Buonocore

Publications and source records attributed to F Buonocore.

13 recordsLinked to original sources
PubMed2006

Evolution of cytokine responses: IL-1beta directly affects intracellular Ca2+ concentration of teleost fish leukocytes through a receptor-mediated mechanism.

In this work we studied the biological activities of recombinant IL-1beta from the teleosts sea bass (Dicentrarchus labrax) and rainbow trout (Oncorhynchus mykiss) by investigating the effects induced on intracellular Ca2+ concentrations ([Ca2+]i) of spleen leucocytes. Splenocytes were loaded with the Ca2+-permeant Fura-2AM, and then stimulated with rIL-1beta. The emitted fluorescence was read for 5 min at 1 min intervals on a dual excitation fluorescence fluorimeter. Results showed that rIL-1beta induced in both species a rise in [Ca2+]i, and a subsequent decrease until 5 min after stimulation. The stimulating effect was dose-dependent in both species reaching a plateau at 200 ng/ml of rIL-1beta, was abolished by heat-treatment of rIL-1beta, and affected in a dose-dependent fashion by treatment of leucocytes with trypsin. These features suggested a functional IL-1 receptor was involved in the binding. The observed rise in [Ca2+]i was not detected in human PBMC and was species-specific, since rIL-1beta from sea bass, trout, and human were unable to interfere each other in the assay. Moreover, incubation of splenocytes with rIL-1beta induced a rapid tyrosine phosphorylation of a 24 kDa polypeptide in both species. This work represents the first evidence of a direct effect on [Ca2+]i induced by IL-1beta and suggests that in the evolution of IL-1 activities, teleost fishes display a peculiar IL-1-associated behaviour that is lacking in mammals.

Animals↗
PubMed2006

Biological activity of cytokines: an evolutionary perspective.

It appears evident that teleost fish are at present the vertebrate group in which, excluding mammals, most information on the immune system is available. However, despite the great impetus on the discovery of genes homologous to mammalian immunomodulatory molecules, the knowledge on biological activities exerted by cytokines is meager. This review reports the present knowledge on the biological activities of cytokine-like and cytokines in invertebrates and cold-blooded vertebrates.

Amphibians↗
PubMed2005

In vivo allograft rejection in a bony fish Dicentrarchus labrax (L.): characterisation of effector lymphocytes.

Lymphoid cell subpopulations involved in allograft rejection in the teleost Dicentrarchus labrax were characterised at the ultrastructural level and quantified by using monoclonal antibodies against T- and B-lymphocytes. T-cells positive for T-cell receptor beta-chain (TcR beta) were detected by reverse transcription/polymerase chain reaction (RT-PCR) and in situ hybridisation by using RNA probes for TcR beta. Flow cytometry detected a similar percentage of T- and B-lymphocytes (around 17%) in the leucocyte-enriched fraction from allografts. Two different types of T-lymphocytes (DLT 15-immunoreactive) infiltrating the allografts were identified by cytomorphology: small cells with high nuclear/cytoplasmic ratio and cells with a higher cytoplasmic content. RT-PCR revealed a single band (513 bp) corresponding to the TcR beta. In situ hybridisation showed that TcR beta-positive cells in the grafted muscle fibres were less numerous compared with DLT 15-positive cells, as evidenced in parallel sections, suggesting that cytotoxic cells might express different TcR phenotypes. DLIg 3-immunoreactive Ig-producing lymphocytes had: 1) a high nuclear/cytoplasmic ratio or 2) a larger size similar to that of pre-plasma cells (plasma cells lacked any membrane labelling).

Animals↗
PubMed2005

Lipase and antibacterial activities of a recombinant protein from the accessory glands of female Phlebotomus papatasi (Diptera: Psychodidae).

The reproductive accessory glands of the adult female have a functional versatility in insects, contributing to reproduction in various ways. The major protein secreted by the accessory glands of female Phlebotomus papatasi (Diptera, Psychodidae) has already been characterised and named PhpaLIP (for P. papatasi lipase) because, in terms of its amino-acid sequence, it is very similar to a wide range of vertebrate lipases. The gene coding for PhpaLIP has now been cloned into a pQE30 vector and expressed in Escherichia coli. When the recombinant PhpaLIP was tested in vitro, it was found to have not only lipase-like activity (when p-nitrophenyl caprylate was used as the substrate) but also specific antibacterial activity against some Gram-positive and Gram-negative bacteria. The possible physiological roles of PhpaLIP in P. papatasi are discussed, in the light of these results.

Actinomycetales↗
PubMed2002

The immune system of sea bass, Dicentrarchus labrax, reared in aquaculture.

The sea bass Dicentrarchus labrax is one the most important seawater fish species of south Europe and Mediterranean aquaculture, and studies on its immune system are important for both scientific and applied purposes. In this paper, we summarise the results obtained in studies of the immune system in this species, and present original data on cell-mediated acquired immune response.

Animals↗
PubMed2001

Phylogeny of cytokines: molecular cloning and expression analysis of sea bass Dicentrarchus labrax interleukin-1beta.

In this paper the cloning of interleukin-1beta (IL-1beta) from the fish Dicentrarchus labrax (sea bass) is described. Using degenerate primers designed from known IL-1beta sequences, a cDNA fragment was amplified by PCR and elongated by 3' and 5' RACE to give the full-length coding sequence for sea bass IL-1beta. The cDNA is 1292 bp, lacks a putative ICE cut site, and codes for a deduced peptide of 29.4 kDa with a pI of 5.1. Sequence analysis showed highest amino acid similarity with rainbow trout (62%), Xenopus (46%), and carp (45.5%) IL-1beta sequences. Expression studies show that sea bass IL-1beta can be upregulated by bacterial lipopolysaccharide both in vitro and in vivo in leucocytes from blood, head-kidney, spleen, gills and liver, whereas the IL-1beta transcript was not detectable in thymus and gut-associated lymphoid tissue. Northern blot analysis with head-kidney leucocyte RNA showed a main LPS-upregulated band at 1.3 kb, and two minor bands at 0.9 and 3.0 kb, respectively. Phylogenetic comparisons with IL-1beta from other vertebrates is presented.

Amino Acid Sequence↗
PubMed2000

Immunopurification of T-cells from sea bass Dicentrarchus labrax (L.).

The monoclonal antibody DLT15, specific for thymocytes and peripheral T-cells of the teleost fish Dicentrarchus labrax (sea bass), was used to purify immunoreactive cells from blood and gut-associated lymphoid tissue. The purification was performed by immuno-magnetic sorting of leucocyte fractions enriched by Percoll density gradient centrifugation, and the purity of the isolated cells was estimated by cytofluorimetric analysis. Following a single step, the percentage of DLT15-purified cells was 88 +/- 10% for gut-associated lymphoid tissue and 79 +/- 18% for blood leucocytes. DLT15-purified cells from gut-associated lymphoid tissue were employed for RNA extraction and cDNA synthesis. In RT-PCR experiments using as primers degenerate oligonucleotides corresponding to the peptide sequence MYWY and VYFCA of the trout TcR beta chain, a 203 bp product was amplified. When sequenced, the cDNA was found to show 60% nucleotide identity to the trout TcRV beta 3. By 3'-RACE the cDNA was elongated to obtain the TcR constant region, with high similarity to other fish TcR sequences. These results strongly suggest that cells recognised by DLT15 are putative T lymphocytes.

Amino Acid Sequence↗
PubMed1991

Purification and characterization of a veratryl alcohol oxidase enzyme from the lignin degrading basidiomycete Pleurotus ostreatus.

A veratryl alcohol oxidase (VAO) enzyme was discovered in cultures of Pleurotus ostreatus. The enzyme, which oxidizes veratryl alcohol to veratraldehyde reducing O2 to H2O2, was purified to homogeneity and its main structural and catalytic properties have been determined. The enzyme is a glycoprotein and contains FAD as a prosthetic group. The amino acid composition and carboxy- and amino-terminal sequences were determined. Primary aromatic alcohols with methoxy substituents in position four are good substrates for VAO; cinnamyl alcohol is the substrate which is oxidized faster whereas coniferyl alcohol is oxidized at a slower rate. The enzyme is moderately thermostable (t1/2(55 degrees C) about 1.5 h, apparent melting temperature about 60 degrees C). The enzyme stability in 50% water/organic solvents mixtures has also been studied.

Alcohol Oxidoreductases↗
PubMedDate not supplied

Immunopurification of B lymphocytes from sea bass Dicentrarchus labrax (L.).

The monoclonal antibody DLIg3, specific for immunoglobulins and B cells of the teleost fish Dicentrarchus labrax (Mediterranean sea bass), was used to enrich immunoreactive cells from peripheral blood, spleen, and head kidney leukocytes. The purification was performed by immunomagnetic sorting of leukocyte fractions enriched by Percoll density gradient centrifugation, and the purity of the isolated cells was estimated by immunofluorescence and cytofluorimetric analysis. Following a single immunopurification step, the percentages of DLlg3-purified cells were 61% +/- 6% from peripheral blood leukocytes, 66% +/- 5% from splenocytes, and 77% +/- 9% from head kidney cells. DLIg3-immunopurified cells, from the head kidney of antigen-primed fish displayed an enhanced proliferation index when incubated with the immunization antigen. DLIg3-purified cells from head kidney lymphoid tissue were employed for RNA extraction and complementary DNA synthesis, and in reverse transcriptase polymerase chain reaction experiments using specific primers corresponding to the sequences of the sea bass immunoglobulin light chain, and of T-cell receptor. DLIg3-purified cells displayed enhanced expression of the immunoglobulin gene, and lower expression of T-cell receptor.

Animals↗