Search results for " T-Cell"
showing 10 items of 320 documents
THE LEVEL OF SOLUBLE GRANZYME A IS ELEVATED IN THE PLASMA AND IN THE Vgamma9/Vdelta2 T CELL CULTURE SUPERNATANTS OF PATIENTS WITH ACTIVE BEHCET'S DIS…
2004
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.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.Significantly high levels of GrA were found in the serum and supernat…
Impairment of gamma/delta T lymphocytes in elderly: implications for immunosenescence
2004
Gamma/delta T lymphocytes cells recognize the antigen in a non-classical way and are considered the third branch of the immune system devoted to defend the integrity of the body. Ageing is characterized by an impairment of the main way of protection (the adaptive branch) but, successfully aged people show compensatory mechanisms of defense such as proneness to inflammation. Moreover, very old subjects show an increased number of NK cells. We have previously demonstrated that gamma delta T lymphocytes are reduced in elderly. In the present paper we have studied some characteristics of these cells to evaluate the possibility that these cells might balance the decreased action of the adaptive …
Sex-specific phenotypical and functional differences in peripheral human Vγ9/Vδ2 T cells
2006
Abstract Vγ9/Vδ2 T cells constitute a minor proportion of human peripheral blood T cells that can expand rapidly upon infection with microbial pathogens. Vγ9/Vδ2 T cell numbers change characteristically with age, rising from birth to puberty and gradually decreasing again beyond 30 years of age. In adults, female blood donors have significantly higher levels than males, implying that circulating Vγ9/Vδ2 T cells in women remain elevated for a longer period in life and drop less strikingly than in men. This loss in men is accompanied by a substantial depletion of CD27−CD45RA− and CD27−CD45RA+ effector T cells and a parallel increase in CD27+CD45RA− central memory T cells while in women, the d…
Vgamma9/Vdelta2 T lymphocytes in Italian patients with Behçet's disease: evidence for expansion, and tumour necrosis factor receptor II and interleuk…
2002
Behçet's disease is a multisystem disease in which there is evidence of immunological dysregulation. It has been proposed that gamma/delta T cells are involved in its pathogenesis. The aim of the present study was to assess the capacity of gamma/delta T cells with phenotype Vgamma9/Vdelta2, from a group of Italian patients with Behçet's disease, to proliferate in the presence of various phosphoantigens and to express tumour necrosis factor (TNF) and IL-12 receptors. Twenty-five patients and 45 healthy individuals were studied. Vgamma9/Vdelta2 T cells were analyzed by fluorescence activated cell sorting, utilizing specific monoclonal antibodies. For the expansion of Vgamma9/Vdelta2 T cells, …
Individual and common antigen-recognition sites of liver-derived T cells in patients with autoimmune hepatitis.
2003
Autoimmune hepatitis (AIH) is characterized by dense T-cell infiltrations in the liver tissue, but little is known how T cells influence the pathogenesis. To address this question, the distribution of T-cell receptor variable beta-chain (TCR Vbeta) transcripts of peripheral blood and liver-infiltrating T cells from previously untreated patients with newly diagnosed acute exacerbated AIH was investigated. Furthermore, the lengths and sequences of complementary-determining region 3 (CDR3) were studied. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis and CDR3 spectratyping revealed multiple clonal expansions of liver-infiltrating T cells but not peripheral T cells within vari…
A phase II study of alemtuzumab, fludarabine, cyclophosphamide, and doxorubicin (Campath-FCD) in peripheral T-cell lymphomas
2010
The clinical course of peripheral T-cell lymphoma (PTCL) is usually aggressive and the prognosis unfavorable. Therefore, there is a need for improvement of treatment options. Patients with newly diagnosed (n = 27) or refractory/relapsed (n = 11) PTCL received a combination of alemtuzumab, fludarabine, cyclophosphamide, and doxorubicin. The overall response rate (ORR) was 61%, with a complete response rate of 39%. In newly diagnosed patients the ORR was 63%, the median overall survival 25.9 months, and progression-free survival 11.8 months. In relapsed/refractory patients the median OS was 6.1 months. The most frequent grade 3/4 toxicities were leukopenia (95% of patients) and thrombocytopen…
Pentoxifylline Inhibits Vγ9/Vδ2 T Lymphocyte Activation of Patients with Active Behçet's Disease in Vitro
2007
The aim of this study is to evaluate the in vitro effect of pentoxifylline (PTX) on T Vgamma9/Vdelta2 lymphocyte function in Behçets disease (BD). We investigated the effect of PTX on Vgamma9/Vdelta2 T cell expansion and expression of TNFRII receptor and perforin content before and after PTX addition by means of FACS analysis lymphocyte cultures from patients with active and inactive BD and healthy subjects. The addition of PTX at a concentration of 1 mg/ml determined a significant inhibition of cell expansion, a down regulation of TNF receptor expression and inhibited the PMA-induced degranulation of perforin. Taken together these data indicate that PTX is capable of interfering with Vgamm…
Longitudinal analysis of the T-cell receptor (TCR)-VA and -VB repertoire in CD8+T cells from individuals immunized with recombinant hepatitis B surfa…
2002
SUMMARYRecent studies have suggested that vaccination induces alterations in the T cell receptor (TCR) repertoire. We investigate the diversity of the TCR repertoire after immunization with a recombinant hepatitis B surface vaccine in seven healthy subjects in CD8+ T cells in peripheral blood lymphocytes. Cellular immune responses were monitored over time by sorting CD8 T cells followed by TCR-VA and -VB complementarity determining region 3 (CDR3) analysis. Frequency of individual VB families was determined by flow cytometry. TCR-VA/VB repertoires obtained from CD8+ T cells drawn after vaccination were compared to the TCR repertoire determined prior to vaccination. Monoclonal TCR transcript…
Liver follicular helper T-cells predict the achievement of virological response following interferon-based treatment in HCV-infected patients.
2012
Background Here, we assessed the presence of intrahepatic follicular helper T-cells (TFH) in a cohort of consecutive genotype 1 (G1) chronic hepatitis C (CHC) patients comprising non-responders (NRs), relapsers (RRs) or those with sustained virological response (SVR) to pegylated interferon and ribavirin, and tested their relation with the response to antiviral treatment. Methods A total of 78 patients with G1 CHC (30 SVR, 15 RR and 33 NR), comparable for sex, age, viral load and fibrosis were evaluated by immunohistochemistry for liver content of PD1+Bcl6+ TFH cells. The number of TFH cells in the immunostained sections was counted out of five representative high-power microscopic fields (…
Partial and Ineffective Activation of Vγ9Vδ2 T Cells by Mycobacterium tuberculosis-Infected Dendritic Cells
2010
Abstract γδ T cells and dendritic cells (DCs) participate in early phases of immune response against Mycobacterium tuberculosis. We investigated whether a close functional relationship exists between these two cell populations using an in vitro coculture in a human system. Vγ9Vδ2 T cells induce full maturation of M. tuberculosis-infected immature DCs, as demonstrated by upregulation of the costimulatory CD80, CD86, CD40, and HLA-DR molecules on infected DCs after 24 h of coculture. Reciprocally, infected DCs induced substantial activation of Vγ9Vδ2 T cells upon coculture, which was cell-to-cell contact and TCR dependent, as demonstrated in transwell experiments. However, infected DCs select…