Biomedical subjects

F Dieli

Publications and source records attributed to F Dieli.

78 records · Page 5Linked to original sources

PubMedDate not supplied

Production of T suppressor factor specific for the hapten picryl chloride requires both T suppressor cells and an antigen-specific, genetically restricted second signal.

We investigated the requirement for activation of T suppressor cells specific for the hapten picryl chloride and the release of hapten-specific T suppressor factor. Using an in vivo experimental system, we report that activation of T suppressor cells and the consequent release of T suppressor factor required two signals: one was provided by primed T suppressor cells, i.e. spleen cells from mice injected with the tolerogen picrylsulphonic acid, and the other was provided by the specific antigen in the context of H-2 gene products. Mechanisms by which the interaction between these two signals led to activation of T suppressor cells and the production of T suppressor factor, as well as a comparison with other antigen-specific suppressor systems, are discussed.

Animals↗

PubMedDate not supplied

Genetic control of C3 production by the S region of the mouse MHC.

The present paper reports evidence indicating that the level of the third complement component (C3) is regulated by the S region of the murine H-2 complex. In fact, using congenic strains of mice we demonstrate that mice with the k haplotype at the S region show high C3 levels, whereas mice with the d haplotype at the S region show low C3 levels.

Alleles↗

PubMedDate not supplied

In vitro effects of aminobisphosphonates on Vgamma9Vdelta2 T cell activation and differentiation.

In this study we have evaluated the in vitro effects of four different aminobisphosphonates, alendronate, risedronate, neridronate and zoledronate, on Vgamma9Vdelta2 T cell activation and differentiation. All tested aminobisphosphonates induce an IL-2-dependent activation and expansion of Vgamma9Vdelta2 T lymphocytes in primary PBMC cultures of healthy donors. Most notably, they also determine a different distribution of Vgamma9Vdelta2 T cell subsets, with decrease of T(naive) and T(CM) cells and increase of T(EM) and T(EMRA) Vgamma9Vdelta2cells, indicating that in vitro treatment with aminobisphosphonates induces Vgamma9Vdelta2 T lymphocytes to differentiate towards an effector/cytotoxic phenotype. Accordingly, Vgamma9Vdelta2 T lymphocytes cultured with aminobisphosphonates and IL-2 showed a major content of IFN-gamma and acquired the ability to kill tumor target cells.

Bone Density Conservation Agents↗

PubMedDate not supplied

Atrial natriuretic peptide secretion during development of the rat supraoptic nucleus.

Since a relationship between atrial natriuretic peptide and oxytocin was recently demonstrated in the heart (Gutkowska et al., 1997), the aim of this study was to determine whether a relationship between the two peptides is present also in the rat hypothalamus. For this purpose, we measured ANP-ontogeny in the rat hypothalamus immunohistochemically and compared it with oxytocin-ontogeny which we previously studied. The results showed that the ANP-peptide and mRNA-ANP start at the 18th day of the fetal life. Our earlier data for oxytocin in the rat hypothalamus showed that only mRNA-oxytocin appeared the 18th day of foetal life (Farina Lipari et al., 2001); thus, at the 18th day of foetal life, mRNA-ANP, ANP-peptide and mRNA-oxytocin are present. We conclude that in the hypothalamus, differently from that in the heart, ANP might play a role on the synthesis of the oxytocin since ANP and its mRNA appear earlier than oxytocin.

Animals↗

PubMedDate not supplied

The level of soluble Granzyme A is elevated in the plasma and in the Vgamma9/Vdelta2 T cell culture supernatants of patients with active Behçet's disease.

OBJECTIVE: Gramzyme A (GrA) is a serine proteinase with trypsin-like activity that is released extracellularly during the degranulation of cytotoxic cells. Among the cytotoxic cells, gamma/delta T cells participate in the early phases of the immune response and are known to express perforin and granzymes constitutively in agreement with their cytolytic pontential. METHODS: GrA activity was detected using the synthetic substrate N-alpha-benzyloxycarbonyl-L-lysine thiobenzyl ester in the plasma and supernatants of peripheral blood mononuclear cell cultured in the presence of Dimethylallyl pyrophosphate to obtain Vgamma9/Vdelta2 T cell expansion. RESULTS: Significantly high levels of GrA were found in the serum and supernatants of lymphocytes from patients with active Behçet's disease cultured in the presence of DMAPP. Levels were found to be significantly lower after remission. A positive correlation was observed between GrA levels in the supernatants and the Vgamma9/Vdelta2 T cell expansion factor. CONCLUSION: These results strongly suggest that Vgamma9/Vdelta2 T cells are active participants in the pathogenesis of the disease through their degranulation and granzyme release.

Adolescent↗

PubMedDate not supplied

CD1d expression by hepatocytes is a main restriction element for intrahepatic T-cell recognition.

The liver has specific mechanisms to protect itself from infectious agents and to avoid autoimmunity, indicating an important role of the hepatic tissues in antigen presentation and tolerance induction. Since intrahepatic lymphocytes may contribute to the innate immunity and to the liver pathology, it is of interest to analyze the expression of antigen presenting molecules and of the related T cell recognition in liver, and how these change in relation to different diseases. We analyzed the expression of MHC class I, and of CD1-a, -b, -c, and -d proteins on liver tissues from patients with different hepatic diseases. Moreover, in the same patients we studied the intrahepatic and peripheral NKT cell recognition of alpha-galactosyl ceramide antigen in the context of CD1d. Unlike in other tissues, classical MHC class I molecules were poorly expressed in the hepatic compartment, suggesting that inflamed hepatocytes may trigger weak MHC-restricted T cell responses. Nevertheless, we observed a prevalent expression of HLA class I-like CD1d isoform on the hepatocyte surface, indicating that CD1d is the main restriction element in the liver. In patients with viral hepatitis, the intrahepatic CD1d expression parallels the recruitment of CD56+Valpha24Vbeta11+ NKT cells in the liver which recognize CD1d presenting glycolipids such as alpha-galactosyl ceramide, suggesting that the intrahepatic T cell immunity may focus on glycolipid antigens.

Adult↗