Search results for "Lymphocyte"
showing 10 items of 2280 documents
Definition of discrete signals involved in human T-cell activation
1986
Abstract Mitogenic activities of monoclonal antibodies directed at denned receptor structures expressed on the surface of mature human T lymphocytes were employed to study, in detail, signals involved in primary T-cell activation. Based on differential requirements for stimulation, two discrete pathways of human T-cell activation can be defined: the antigen-induced mode of activation initiated through the Ti-T3 antigen-receptor complex and an alternative pathway which can be triggered by monoclonal antibodies directed at the T11 glycoprotein. Perhaps more importantly, the approach taken here allows the definition of stable intermediate cellular stages within the activation cascade and, thus…
The role of recent thymic emigrant-regulatory T-cell (RTE-Treg) differentiation during pregnancy.
2014
During pregnancy, regulatory T cells (Tregs) have a key role in maternal immune tolerance to the semi-allogeneic fetus. Our previous results showed that the naive CD45RA(+)-Treg pool is functionally improved in pregnant women compared with non-pregnant women. Therefore, we examined the thymic output and differentiation of CD45RA(+)CD31(+) recent thymic emigrant (RTE)-Tregs during normal pregnancy and in the presence of preeclampsia. With the onset of pregnancy, the composition of the total CD4(+)CD127(low+/-)FoxP3(+)-Treg pool changed in the way that its percentage of RTE- and CD45RA(-)CD31(+)-memory Tregs decreased strongly, whereas that of the CD45RA(+)CD31(-)-mature naive (MN)-Tregs did …
Activation of T‐Lymphocytes by LDL‐Cholesterol
2008
Native LDL-cholesterol can be mechanically stressed by strong vortexing. According to one hypothesis, mechanical shear stress within the vessel can lead to an aggregation of LDL-cholesterol and subsequently to activation of CD4 and CD8 T-lymphocytes. The goal of this study was to determine the proportion of activated CD4 and CD8 T-lymphocytes that is induced by adding unstressed and mechanically stressed LDL-cholesterol to whole blood samples. Whole blood was taken from 12 healthy subjects. All probands fasted for at least 12 h before blood withdrawal. In each case, 1 ml of whole blood from each subject was incubated for 16 h at 32 degrees C (89.3 degrees F) with concanavalin A (A), without…
B cells in the aged: CD27, CD5, and CD40 expression.
2003
Ageing is characterized by numerous changes in lymphocyte subpopulations. In the present paper we have focused on B cells carrying the surface markers CD27, CD5 and CD40. CD27 is considered a marker of primed (memory) cells and its engagement promotes the differentiation of memory B cells into plasma cells. CD5 is expressed on B1 cells, which are considered to be responsible for T cell-independent antibody production other than autoantibodies. The CD40 molecule binds CD40L (CD154) and is necessary for T-dependent antibody responses. Here we show that the absolute number of CD5+ and CD40+ B cells is decreased in the elderly, while CD27+ B lymphocytes only marginally decrease in centenarians.…
Effects of leflunomide (HWA 486) on expression of lymphocyte activation markers
1993
Leflunomide (HWA 486), an isoxazol derivative, has been shown to be very effective in combating autoimmune diseases and transplantation rejection in a great number of animal models. The main metabolite of leflunomide, A77 1726, is a potent antiproliferative compound. To further elucidate this effect, lymphocytes of healthy human donors were cultured for 24, 48 or 72 h in the presence of PHA or immobilized anti-CD3 antibody. A77 1726 was added at concentrations between 10 and 100 microM. Flow cytometric evaluation of early activation or proliferation markers (IL-2 and transferrin receptors, respectively) showed that their expression was inhibited in a dose-dependent manner by A77 1726. Toget…
Mitochondrial disruption and apoptosis in lymphocytes of an HIV infected patient affected by lactic acidosis after treatment with highly active antir…
2003
Aims: Highly active antiretroviral therapy (HAART) can induce an increase in lactic acid concentrations that seems to be caused by mitochondrial dysfunction induced by the interaction of nucleoside reverse transcriptase inhibitors (NRTIs) with DNA polymerase γ in the mitochondria. Mitochondrial alterations have been described in liver and muscle cells of NRTI treated human immunodeficiency virus (HIV) infected patients. Because lymphocytes are the main target for HIV and because mitochondria are involved in apoptosis, we studied mitochondrial morphology and apoptosis in the lymphocytes of an HIV infected patient with severe lactic acidosis after treatment with stavudine, didanosine, and ind…
Rituximab in refractory pemphigus vulgaris
2008
Pemphigus vulgaris (PV) is a severe chronic autoimmune blistering disease of skin and mucous membranes. The use of systemic corticosteroids in pemphigus has dramatically reduced its mortality rate, but the long-term use of steroids leads to severe side effects, many of which are serious. For this reason it is often necessary to add immunosuppressive agents to the regimen. However, there are occasional refractory cases in which therapy with conventionally accepted modalities is either not efficacious or not possible on account of side effects. Rituximab is a therapeutic monoclonal antibody targeting CD20, an integral membrane protein highly expressed on the surface of pre-B lymphocytes and a…
Analysis of T-Lymphocyte Subsets After Phytohemagglutinin Stimulation in Normal and Type 1 Diabetic Mothers and Their Infants
1992
Our aim was to investigate the immunological status of diabetic pregnancy, which is an overlap of diabetic immunity abnormalities and the immunological modifications normally occurring during pregnancy. METHOD: We studied lymphocyte subpopulations and lymphokine production, after 96 h of phytohemagglutinin (PHA) stimulation, from normal and Type I diabetic pregnant women at delivery time and from the respective cord blood. RESULTS: Peripheral blood mononuclear cells (PBMC) from both normal and Type I diabetic mothers showed an increase in CD8+ and a decrease in CD4+ cells compared to the respective cord blood mononuclear cells (CBMC). Moreover, Type I PBMC showed a lower number of “activate…
In vitro synthesis of glycosaminoglycans in endocrine ophthalmopathy
1992
The effects of humoral and cell-mediated immunity on the glycosaminoglycan synthesis of retrobulbar fibroblasts was evaluated in patients with endocrine ophthalmopathy. After incubation with IgG and sera, secreted glycosaminoglycans, radiolabeled with D-6-3H-glucosamine and 35sulfate, were precipitated with cetylpyridinium chloride and ethanol. Hyaluronic acid synthesis of human retrobulbar fibroblasts after incubation with sera and IgG and after co-culture with lymphocytes was assessed by means of a radiometric test. Patients' IgG, compared to controls', accounted for a higher secretory stimulation of porcine retrobulbar fibroblasts (as measured by cetylpyridinium chloride precipitation) a…
Pregnancy outcomes in women with advanced HIV infection in Italy
2011
Pregnancy has been associated with a low risk of HIV disease progression. Most pregnancies with HIV currently involve women who have not experienced AIDS-defining events, and are clinically classified as Centers for Disease Control and Prevention (CDC) groups A or B. We evaluated the main maternal outcomes among pregnant women with more advanced HIV disease, defined by CDC-C disease stage. Data from the Italian National Program on Surveillance on Antiretroviral Treatment in Pregnancy were used. A total of 566 HIV-infected mothers, 515 in stage A or B (CDC-AB group) and 51 in stage C (CDC-C group) were evaluated. The two groups had similar baseline characteristics. No differences were found …