Examinando por Autor "Cuesta, A"

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Identification of a novel CCR7 gene in rainbow trout with differential expression in the context of mucosal or systemic infection
(Elsevier, 2012) Ordás, MC; Castro, R; Dixon, B; Sunyer, JO; Bjork, S; Bartholomew, J; Korytar, T; Köllner, B; Cuesta, A; Tafalla, C
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. When leukocyte populations were isolated, IgM+ cells, T cells and myeloid cells from head kidney transcribed the CCR7 gene. In blood, both IgM+ and IgT+ B cells and myeloid cells but not T lymphocytes were transcribing CCR7, whereas in the spleen, CCR7 mRNA expression was strongly detected in T lymphocytes. In response to infection with viral hemorrhagic septicemia virus (VHSV), CCR7 transcription was down-regulated in spleen and head kidney upon intraperitoneal infection, whereas upon bath infection, CCR7 was up-regulated in gills but remained undetected in the fin bases, the main site of virus entry. Concerning its regulation in the intestinal mucosa, the ex vivo stimulation of hindgut segments with Poly IC or inactivated bacteria significantly increased CCR7 transcription, while in the context of an infection with Ceratomyxa shasta, the levels of transcription of CCR7 in both IgM+ and IgT+ cells from the gut were dramatically increased. All these data suggest that CCR7 plays an important role in lymphocyte trafficking during rainbow trout infections, in which CCR7 appears to be implicated in the recruitment of B lymphocytes into the gut.
Viral hemorrhagic septicaemia virus (VHSV) up- regulates the cytotoxic activity and the perforin/ granzyme pathway in the rainbow trout RTS11 cell line.
(Elsevier, 2011) Ordás, MC; Cuesta, A; Mercado, L; Bols, NC; Tafalla, C
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. For the first time, the cytotoxic activity of RTS11 against xenogeneic targets has been demonstrated, although this was modest relative to HKLs. Yet the activity in RTS11 was significantly increased by VHSV, as in HKLs. This cytotoxic activity elicited by viral infection appeared to require viral gene expression because inactivated VHSV failed to increase RTS11 cytotoxic activity. As for other immune functions, RTS11 cells provide a model for further studying cytotoxic activities of fish monocyte-macrophages.