Unitus DSpace

T cell receptor beta chain from sea bream (Sparus aurata): molecular cloning, expression and modelling of the complexes with MHC class I

Mon, 31 Dec 2007 23:00:00 GMT

Title: T cell receptor beta chain from sea bream (Sparus aurata): molecular cloning, expression and modelling of the complexes with MHC class I Authors: Scala, Viviana; Casani, Daniela; Costantini, Susan; Facchiano, Angelo M.; Mazzini, Massimo; Scapigliati, Giuseppe; Buonocore, Francesco Abstract: The T cell receptor is a fundamental mediator of the adaptive immune responses, since TR on T cells recognize foreign structures (peptides derived from processed antigens) bound to the major histocompatibility complex (MHC) on APC cells. In the present study, we report the cloning of six TRB chains cDNA sequences from gilthead sea bream (Sparus aurata), a fish of high economical impact in South Mediterranean aquaculture. The V-BETA domains have the canonical features of known teleost and mammalian TR V-BETA domains and have been divided in four different subgroups. A multiple alignment of the six sea bream TRB chains with other known TRB sequences was assembled and showed the conservation of the four cysteine residues involved in disulphide bonds and of some amino acids with an important role in the assembly and signalling of the TR /CD3 complex. Real-time PCR analysis was used to investigate TRB basal expression, that was maximum in the thymus followed by gut, and TRB in vitro expression after stimulation with LPS or PHA-L at 4 and 24 h (only the 4 h stimulation with LPS gave an significant effect). Moreover, the 3D structures of sea bream TRB chains and MHC-I were predicted by homology modelling with the final aim to investigate the interaction surface in the V-BETA/MHC-I complexes. Description: L'articolo è disponibile sul sito dell'editore http://www.sciencedirect.com/

Compartmentalisation of T cells expressing CD8α and TCRβ in developing thymus of sea bass Dicentrarchus labrax (L.)

Mon, 31 Dec 2007 23:00:00 GMT

Title: Compartmentalisation of T cells expressing CD8α and TCRβ in developing thymus of sea bass Dicentrarchus labrax (L.) Authors: Picchietti, Simona; Guerra, Laura; Selleri, Luigi; Buonocore, Francesco; Abelli, Luigi; Scapigliati, Giuseppe; Mazzini, Massimo; Fausto, Anna Maria Abstract: Eggs, larvae, post-larvae and sexually immature juveniles of the teleost Dicentrarchus labrax (L.) were assayed for the expression of genes encoding the T cell receptor b and CD8a. RT-PCR of RNA extracted from larvae revealed TCRb transcripts from day 25 posthatching (ph) and CD8a transcripts from 26 days later. At day 51 ph, CD8a and TCRb mRNAs were localised by in situ hybridisation in thymocytes of the outer and lateral zones of the thymic paired glands. From day 75 ph onwards the signal was mainly detected in the outer region, drawing a cortex–medulla demarcation. In 1-year-old fish, CD8a+ and TCRb+ thymocytes almost filled the cortex and extended in large cords in the medulla. A CD8a TCRb+ subcapsular lymphoid zone was evident near the septa coming from the inner connective capsule that delimited the thymus. The localisation of CD8a and TCRb transcripts demonstrated a compartmentalisation of the juvenile thymus due to distinct localisation of thymocytes at different developmental stages. Description: L'articolo è disponibile sul sito dell'editore http://www.sciencedirect.com/

Effects of administration of probiotic strains on GALT of larval gilthead seabream: immunohistochemical and ultrastructural studies

Sun, 31 Dec 2006 23:00:00 GMT

Title: Effects of administration of probiotic strains on GALT of larval gilthead seabream: immunohistochemical and ultrastructural studies Authors: Picchietti, Simona; Mazzini, Massimo; Taddei, Anna Rita; Renna, Raffaella; Fausto, Anna Maria; Mulero, Victoriano; Carnevali, Oliana; Cresci, Alberto; Abelli, Luigi Abstract: Two bacterial strains Lactobacillus fructivorans (AS17B), isolated from adult seabream (Sparus aurata L.) gut, and Lactobacillus plantarum (906), isolated from human faeces, were administered contemporaneously during seabream development using Brachionus plicatilis and/or Artemia salina and dry feed as vectors. Experimental group A received the probiotic strains already via rotifers from day 5 post-hatch (ph), whereas treatment of group B began with Artemia feeding from day 27 ph. Fish were sampled at day 28 ph (group A and control) and day 99 ph (groups A, B and control) for electron microscopy, histology and immunohistochemistry with the polyclonal antiserum ORa against homologous serum Ig and the mAb G7 specific for seabream acidophilic granulocytes. In all groups, timing and pattern of differentiation of the digestive tract did not differ. Furthermore, neither tissue damage nor manifest inflammation was provoked by probiotic administration. At day 28 ph, the developing GALTalready housed mucosal leucocytes, including Igþ cells but no acidophilic granulocytes. No differences were seen between experimental groups. At day 99 ph, the density of Igþ cells (þ51%) and acidophilic granulocytes (þ284%) was significantly higher (p < 0.05) in group A than in controls. Also group B had a higher density of Igþ cells (þ17%) and acidophilic granulocytes (þ130%) compared with controls, although less pronounced. Light and electron microscopy observations detailed the occurrence of heterogeneous populations of lymphocytes and granulocytes in the developing intestinal mucosa, and highlighted the net expansion of G7þ acidophilic granulocytes (A þ536%, B þ292% vs. control) due to probiotic administration. Description: L'articolo è disponibile sul sito dell'editore http://www.sciencedirect.com/

Morphology and ultrastructure of the cephalic vesicles in two species of the Gonatopus genus: Gonatopus camelinus Kieffer and Gonatopos clavipes (Thunberg) (Hymenoptera, Dryinidae, Gonatopodinae)

Wed, 31 Dec 1997 23:00:00 GMT

Title: Morphology and ultrastructure of the cephalic vesicles in two species of the Gonatopus genus: Gonatopus camelinus Kieffer and Gonatopos clavipes (Thunberg) (Hymenoptera, Dryinidae, Gonatopodinae) Authors: Carcupino, Marcella; Guglielmino, Adalgisa; Mazzini, Massimo; Olmi, Massimo Abstract: The cephalic vesicles of the immature endo-ectoparasitic larvae of Gonatopus camelinus Kieffer and Gonatopus clavipes (Thunberg)were studied using light and elecronic microscopy. The vesicles appear as hollow evaginations of the cephalic body wall and their tegument consists of a monolayered epithelium externally surrounded by a permeable cuticle. In the first larval instars, the epithelial cells are pyramid-shaped and separated by large intercellular spaces. In the last larval instars they are polyhedral and the intercellular spaces are no longer evident.The vesicles have no connection with the gut of iether the host or the larva. These data suggest that nutrients are absoebed by the dryinid larva from haemolymph of the host through the permeable surface of the cephalic vesicles, where they are stored in the lumen and enter the larval haemolymph without passing through the gut. In all immature larval instars the mouth is closed. Description: L'articolo è disponibile sul sito dell'editore http://www.tandfonline.com