Genetic diversity of meat quality related genes in Argentinean pigs.

Genetic influence on pork quality exists between breeds and within a breed. The variation is caused by a large set of genes, and pork quality traits have a multifactorial background. Research into the genetics of meat quality found causative mutations associated with marked effects on pig meat value. This study aimed to investigate the segregation of meat quality-related SNPs and compare their diversity and genetics in commercial and Creole pigs from different farms in the North-West of Argentina. A screen for SNPs in RYR1, PRKAG3, CAST, and SOX6 candidate genes and the differentiation of their genotypes by PCR-RFLP was conducted. All genes were characterized by a high level of polymorphism and heterozygosity, and populations showed no differences in the genetic structure for the analyzed SNPs. These results highlighted the role of pig genotypes as a source of basic variability potentially affecting processed meat products and fresh meat.

Histamine modulates γδ-T lymphocyte migration and cytotoxicity, via Gi and Gs protein-coupled signalling pathways.

BACKGROUND AND PURPOSE: The biogenic amine, histamine plays a pathophysiological regulatory role in cellular processes of a variety of immune cells. This work analyses the actions of histamine on γδ-T lymphocytes, isolated from human peripheral blood, which are critically involved in immunological surveillance of tumours. EXPERIMENTAL APPROACH: We have analysed effects of histamine on the intracellular calcium, actin reorganization, migratory response and the interaction of human γδ T cells with tumour cells such as the A2058 human melanoma cell line, the human Burkitt's Non-Hodgkin lymphoma cell line Raji, the T-lymphoblastic lymphoma cell line Jurkat and the natural killer cell-sensitive erythroleukaemia cell line, K562. KEY RESULTS: γδ T lymphocytes express mRNA for different histamine receptor subtypes. In human peripheral blood γδ T cells, histamine stimulated Pertussis toxin-sensitive intracellular calcium increase, actin polymerization and chemotaxis. However, histamine inhibited the spontaneous cytolytic activity of γδ T cells towards several tumour cell lines in a cholera toxin-sensitive manner. A histamine H(4) receptor antagonist abolished the histamine induced γδ T cell migratory response. A histamine H(2) receptor agonist inhibited γδ T cell-mediated cytotoxicity. CONCLUSIONS AND IMPLICATIONS: Histamine activated signalling pathways typical of chemotaxis (G(i) protein-dependent actin reorganization, increase of intracellular calcium) and induced migratory responses in γδ T lymphocytes, via the H(4) receptor, whereas it down-regulated γδ T cell mediated cytotoxicity through H(2) receptors and G(s) protein-coupled signalling. Our data suggest that histamine activated γδ T cells could modulate immunological surveillance of tumour tissue.

Microtubules regulate expression of ICAM-1 in epidermoid cells (KB cells).

The intercellular adhesion molecule-1/CD54 (ICAM-1) functions as a counterreceptor for other adhesion molecules (e.g. the lymphocyte function-associated antigen-1/CD11a/CD18) required for the interaction of a large variety of cells with leucocytes. Constitutive expression of ICAM-1 in human epidermoid cells (KB cells) is low, but inducible by interferon-gamma (IFN-gamma). Treatment of KB cells with microtubule-disrupting agents, like colchicine, nocodazole and vinblastine, potentiated the constitutive and cytokine-induced ICAM-1 expression on the cell surface. Actinomycin D inhibited microtubule-disrupting agent-induced ICAM-1 surface expression. Increased steady-state levels of ICAM-1 transcripts were found after treatment of KB cells with microtubule-disrupting agents. However, microtubule-disrupting agents neither altered the glyceraldehyde-3-phosphate dehydrogenase mRNA levels nor the amount of expressed alpha(2)-, alpha(3)-and beta(1)-integrins at the cell surface. In addition, they did not change the ICAM-1 mRNA half-life. These studies indicate a control function of the microtubule network on the expression of ICAM-1.

Analysis of macrophage presence in murine placenta: influence of age and parity status.

PROBLEM: Beneficial effects of multiparity status have been previously reported by different authors. However, this fact has not been fully explained. Taking into consideration the influence of the parity status on the in vitro asymmetric/protective antibodies and the fact that interleukin-6 (IL-6) is involved in the production and immune-regulatory functions of placental macrophages, the aim of this work was to compare the placental IL-6 production and tissue macrophage presence in mice with different age and parity status. METHOD OF STUDY: Three groups of mice (CBA/J x CBA/J) were analyzed: primiparous young (PY: 3.0 +/- 0.5 months old), primiparous old (PO: 8.5 +/- 0.5 months old), and multiparous old (MO: 8.5 +/- 0.5 months old, with three to four previous pregnancies). Macrophage and IL-6 were identified in placental tissue by immunohistochemistry employing anti-F4/80 or anti-IL-6 antibodies. IL-6 secretion was analyzed in the placental culture supernatants by enzyme-linked immunosorbent assay. RESULTS: The results obtained indicate that, despite the level of macrophages observed in the PO placentae was higher than in PY ones, their expression in MO placentae was very much increased, appearing like a thick layer between decidua and trophoblast. However, no significant difference was found among the groups in the tissue expression of IL-6 and in IL-6 secreted in vitro. CONCLUSIONS: Our data indicate that parity status influences the number of local macrophages and might provide evidence that could explain the known beneficial effect of multipaternity. We suggest that the number of previous pregnancies favor the production of a 'protective' population of macrophages.