Effect of β-glucans on rainbow trout (Oncorhynchus mykiss) IgM B cells.

β-glucans are carbohydrates present in the cell wall of many fungi, which are often used as immunostimulants in feeds for farmed species. Their capacity to activate innate immune responses directly acting on innate cell populations has been widely documented in fish. However, whether they can affect the functionality of adaptive immune cells has been scarcely explored.

L-methionine supplementation modulates IgM B cell responses in rainbow trout.

The interest in dietary amino acids (AAs) as potential immunomodulators has been growing the recent years, since specific AAs are known to regulate key metabolic pathways of the immune response or increase the synthesis of some immune-related proteins. Methionine, tryptophan and lysine are among the ten essential AAs for fish, meaning that they cannot be produced endogenously and must be provided through the diet. To date, although dietary supplementation of fish with some of these AAs has been shown to have positive effects on some innate immune parameters and disease resistance, the effects that these AAs provoke on cells of the adaptive immune system remained unexplored.

Yersinia ruckeri infection activates local skin and gill B cell responses in rainbow trout.

Teleost fish lack organized structures in mucosal tissues such as those of mammals, but instead contain dispersed B and T cells with the capacity to respond to external stimuli. Nonetheless, there is still a great lack of knowledge regarding how B cells differentiate to plasmablasts/plasma cells in these mucosal surfaces. To contribute to a further understanding of the mechanisms through which fish mucosal B cells are activated, in the current study, we have studied the B cell responses in the skin and gills of rainbow trout (Oncorhynchus mykiss) exposed to Yersinia ruckeri.

Differential response of RTGUTGC and RTGILL-W1 rainbow trout epithelial cell lines to viral stimulation.

Mucosal surfaces constitute the main route of entry of pathogens into the host. In fish, these mucosal tissues include, among others, the gastrointestinal tract, the gills and the skin. However, knowledge about the mechanisms of regulation of immunity in these tissues is still scarce, being essential to generate a solid base that allows the development of prevention strategies against these infectious agents.

First in vivo evidence of pituitary adenylate cyclase-activating polypeptide antiviral activity in teleost.

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a multifunctional neuropeptide belonging to the glucagon/secretin superfamily. In teleost fish, PACAP has been demonstrated to have an immunomodulatory role. Although previous studies have shown that viral/bacterial infections can influence the transcription of PACAP splicing variants and associated receptors in salmonids, the antiviral activity of PACAP has never been studied in teleost.

Functional nutrition modulates the early immune response against viral haemorrhagic septicaemia virus (VHSV) in rainbow trout.

Although viruses represent a major threat for cultured fish worldwide, the commercialization of vaccines capable of providing effective and long-lasting protection is still lacking for most of these viral diseases. In this situation, the use of supplemented diets could be a suitable strategy to increase the immune status of the fish and reduce the impact of viral pathogens. Among possible immunostimulants that could be included in these functional feeds, some studies have previously shown that certain β-glucans can significantly increase certain immune parameters of fish and reduce the impact of viral diseases.

Identification of a novel CCR7 gene in rainbow trout with differential expression in the context of mucosal or systemic infection.

In mammals, CCR7 is the chemokine receptor for the CCL19 and CCL21 chemokines, molecules with a major role in the recruitment of lymphocytes to lymph nodes and Peyer's patches in the intestinal mucosa, especially naïve T lymphocytes. In the current work, we have identified a CCR7 orthologue in rainbow trout (Oncorhynchus mykiss) that shares many of the conserved features of mammalian CCR7. The receptor is constitutively transcribed in the gills, hindgut, spleen, thymus and gonad.

Viral hemorrhagic septicaemia virus (VHSV) up-regulates the cytotoxic activity and the perforin/granzyme pathway in the rainbow trout RTS11 cell line.

A survey of immune-relevant genes that might be up-regulated in response to viral hemorrhagic septicaemia virus (VHSV) in the rainbow trout monocyte-macrophage cell line, RTS11, unexpectedly revealed an increased expression of perforin (PRF) and granzyme (GRZ) genes, which represent components of the major cytotoxic pathway. The natural killer-enhancing factor (NKEF), also known to modulate cytotoxic activity, was up-regulated at the gene but strikingly down-regulated at protein level. The expression of these genes was not affected in head kidney leukocytes (HKLs) infected with VHSV, leading us to evaluate the potential cytotoxic activity of RTS11 and HKLs.

CK12, a rainbow trout chemokine with lymphocyte chemo-attractant capacity associated to mucosal tissues.

Although many chemokine genes have been identified in rainbow trout (Oncorhynchus mykiss) as in other teleost species, almost no studies focused on their biological role have been conducted, despite the fact that no clear inferences as to their functions can be made based on their low similarity to mammalian counterparts. In the current work, we have studied the regulation of mRNA transcription and protein expression of CK12, a rainbow trout CC chemokine previously catalogued within the CCL19/21/25 phylogenetic group. Our studies revealed that CK12 is strongly expressed both at mRNA and protein level in mucosal tissues.

Specific regulation of the chemokine response to viral hemorrhagic septicemia virus at the entry site.

The fin bases constitute the main portal of rhabdovirus entry into rainbow trout (Oncorhynchus mykiss), and replication in this first site strongly conditions the outcome of the infection. In this context, we studied the chemokine response elicited in this area in response to viral hemorrhagic septicemia virus (VHSV), a rhabdovirus. Among all the rainbow trout chemokine genes studied, only the transcription levels of CK10 and CK12 were significantly upregulated in response to VHSV.

Bilateral Leydig cell tumor in a six-year-old intersex goat affected by Polled Intersex Syndrome.

A 6-year-old, sterile, Blanca Celtibérica breed adult doe was referred to our faculty. The doe had external female genitalia, a short anogenital distance, and normally shaped udders. Masculinization signs in the head shape and male behavior were also noted at the time of referral.

Assessment of in vivo effects of the prestige fuel oil spill on the mediterranean mussel immune system.

A laboratory experiment was carried out to study immune function alteration of the mussel Mytilus galloprovincialis when exposed to the Prestige oil spilled in November 2002 on the northwestern Spanish coast. Mussels were maintained for 4 months in tanks with flowing seawater and with 1, 2, and 0 kg (controls) Prestige fuel oil. Polycyclic aromatic hydrocarbon concentrations, which were determined in gills and digestive glands, were higher in digestive glands.

Turbot TNFalpha gene: molecular characterization and biological activity of the recombinant protein.

The tumor necrosis factor (TNF) superfamily is composed by several proteins with similar structure and functions. One of the main representatives of this family is TNF-alpha (TNFalpha), a proinflammatory cytokine which is produced by different immune cells and presents a wide variety of activities. Using the RACE technique, we have cloned and sequenced the turbot TNF cDNA.

Molecular cloning and expression analysis of interferon regulatory factor-1 (IRF-1) of turbot and sea bream.

The interferon regulatory factor (IRF) family comprises transcription factors that regulate the expression of interferon and interferon-related cytokines. Using the RACE technique, we have determined the complete cDNA sequence of turbot (Scophthalmus maximus) and sea bream (Sparus aurata) IRFs. These sequences shared characteristics with other IRFs of fish, mammals and birds, and showed high similarity with IRF-1.

Sequence of the Small Subunit Ribosomal RNA Gene of Perkinsus atlanticus-like Isolated from Carpet Shell Clam in Galicia, Spain.

Parasites identified as Perkinsus atlanticus have been reported infecting carpet shell clams in Galicia (northwest Spain). We have sequenced the 18S ribosomal RNA gene of in vitro cultured Perkinsus atlanticus-like or hypnospores from diseased clams, and compared it with the same genomic region from P. marinus and Perkinsus sp.

Modulation of the chemiluminescence response of Mediterranean mussel (Mytilus galloprovincialis) haemocytes.

The influence of several factors on the chemiluminescence (CL) activity of haemocytes from the Mediterranean mussel (Mytilus galloprovincialis) was studied. Haemocytes were stimulated in vitro with different concentrations of zymosan, phorbol 12-myristate 13-acetate (PMA) and lipopolysaccharide (LPS) (adding superoxide dismutase, SOD, to the zymosan-stimulated haemocytes in order to test the specificity of the reaction). The in vitro effect of the clam pathogens Vibrio tapetis (bacteria) and a Perkinsus atlanticus-like protozoan tentatively named Pseudoperkinsus taapetis on the mussel haemocytes CL response was also assessed.

Immune parameters in carpet shell clams naturally infected with Perkinsus atlanticus.

Defence parameters of non-infected clams (Ruditapes decussatus) and clams heavily infected with Perkinsus atlanticus were assessed. Cellular (haemocyte density and phagocytic activity) and humoral (lysozyme and anti-bacterial activities, protein concentration and agglutination titre) parameters were measured in clams collected in an area enzootic for P. atlanticus.

[Scanography in head injuries. Critical study of 500 cases].

In 22 months, about 2 000 patients were hospitalized for head injury and 410 of these had computerized tomography to determine the presence and extent of intracranial pathology. 165 patients had normal C.T.