Search results for "Lymphocyte"
showing 10 items of 2280 documents
Monitoring of anti-vaccine CD4 T cell frequencies in melanoma patients vaccinated with a MAGE-3 protein.
2005
Abstract Quantitative evaluation of T cell responses of patients receiving antitumoral vaccination with a protein is difficult because of the large number of possible HLA-peptide combinations that could be targeted by the response. To evaluate the responses of patients vaccinated with protein MAGE-3, we have developed an approach that involves overnight stimulation of blood T cells with autologous dendritic cells loaded with the protein, sorting by flow cytometry of the T cells that produce IFN-γ, cloning of these cells, and evaluation of the number of T cell clones that secrete IFN-γ upon stimulation with the Ag. An important criterion is that T cell clones must recognize not only stimulat…
IL-2 receptor beta-chain signaling controls immunosuppressive CD4+ T cells in the draining lymph nodes and lung during allergic airway inflammation i…
2008
Abstract IL-2 influences both survival and differentiation of CD4+ T effector and regulatory T cells. We studied the effect of i.n. administration of Abs against the α- and the β-chains of the IL-2R in a murine model of allergic asthma. Blockade of the β- but not the α-chain of the IL-2R after allergen challenge led to a significant reduction of airway hyperresponsiveness. Although both treatments led to reduction of lung inflammation, IL-2 signaling, STAT-5 phosphorylation, and Th2-type cytokine production (IL-4 and IL-5) by lung T cells, IL-13 production and CD4+ T cell survival were solely inhibited by the blockade of the IL-2R β-chain. Moreover, local blockade of the common IL-2R/IL-15R…
Contrary roles of IL-4 and IL-12 on IL-10 production and proliferation of human tumour reactive T cells.
1997
The cytokine profile of tumour reactive T cells is likely to play a central role in their function. However, little is known about how cytokine patterns of tumour reactive T cells can be regulated. Here, the authors investigated the influence of exogenous regulatory cytokines in addition to interleukin-2 (IL-2) on cytokine patterns and the proliferation of T cells recognizing an autologous sarcoma cell line. In this system, IL-4 and IL-12 showed the most polarizing influences on tumour reactive T cells. Exogenous IL-4 induced a predominant production of IL-4 while decreasing the interferon-gamma (IFN-gamma) and IL-10 production by tumour reactive T cells. It also stimulated the growth of tu…
Allergic contact dermatitis: understanding the immune response and potential for targeted therapy using cytokines.
1997
Allergic contact dermatitis is the most common job-related disease of the western world. The only available treatments are avoidance of contact with the allergen and the use of potent corticosteroids. Recently, the role of cytokines in the pathogenesis of this disease has been studied and, besides defining the key molecules and basic cellular immune responses responsible for disease development, these studies might help to develop new therapeutic strategies to target cytokines and thereby try to alter or abrogate ongoing immune reactions.
Nanoparticles and antigen-specific T-cell therapeutics: A comprehensive study on uptake and release
2015
Aim: T lymphocytes are used as cellular therapeutics in many disease entities including cancer. We investigated the uptake and retention of nanoparticles (NPs) by these nonphagocytic cells. Materials & methods: Uptake, release and toxicity of various polymeric NP preparations were analyzed by flow cytometry, confocal laser scanning microscopy and transmission electron microscopy. T-cell effector functions were measured using IFN-γ-ELISPOT and 51Chromium-release assays. Results: Amino-functionalized NPs were efficiently ingested by antigen-specific T cells without adversely influencing effector functions. NPs were stored in membrane-surrounded vesicles, with major proportions released e…
The immunodominant CD8 T cell response to the human cytomegalovirus tegument phosphoprotein pp65(495-503) epitope critically depends on CD4 T cell he…
2011
Abstract Immunodominance hierarchies operating in immune responses to viral Ags limit the diversity of the elicited CD8 T cell responses. We evaluated in I-Ab+/A2-HHD-II and HLA-DR1+/A2-DR1 mice the HLA-A*0201–restricted, multispecific CD8 T cell responses to the human CMV tegument phosphoprotein pp65 (pp65) Ag. Vaccination of mice with pp65-encoding DNA elicited high IFN-γ+ CD8 T cell frequencies to the pp65495–503/(e6) epitope and low responses to the pp65320–328/(e3) and pp65522–530/(e8) epitopes. Abrogation of the e6-specific immunity efficiently enhanced e3- and e8-specific T cell responses by a pp65Δ501–503 DNA vaccine. The immunodominant e6-specific (but not the e3- and e8-specific) …
A novel plasmid DNA electroporation method allows transfection of murine DC.
2007
Under steady state conditions dendritic cells (DC) exert tolerogenic function, but acquire potent immunogenic function due to strong upregulation of costimulatory molecules and proinflammatory cytokines. In numerous studies the potential of modified DC to induce tolerance or immune reactions towards a distinct antigen has been demonstrated. However, DC are refractory to transfection with plasmid DNA by non-viral methods. In this study we have tested the suitability of a newly developed electroporation device to transfect immature murine bone-marrow derived DC (BM-DC). Transfected BM-DC expressed reporter molecules at considerable extent which renders this method suitable to perform all kind…
Quantitative representation of all T cells committed to develop into cytotoxic effector cells and/or interleukin 2 activity-producing helper cells wi…
1984
A limiting dilution culture system based on stimulation with concanavalin A (Con A) has been used to study the quantitative distribution of helper and of cytotoxic precursor cells in Lyt-2-defined subpopulations of murine T cells. Virtually all of the selected Lyt-2+ and Lyt-2-T cells grow and expand to large clonal colonies within an 8-9-day culture period. Our data show that upon stimulation with Con A, 90% of the Lyt-2-T cells were capable to produce interleukin 2 (IL 2) activity. In addition, IL 2 activity is produced by 8-10% of Lyt-2+ T cells. However, at the clonal level, the average of the IL2 activity produced by Lyt-2+ T cells is about 8-fold less as compared to Lyt-2-T cells. Pre…
T helper cell populations: As flexible as the skin?
2011
T helper cells can be defined by the cytokines they produce and are divided into Th1, Th2, Th17, T(FH) or regulatory T cells. Th17 cells have been shown to produce, in addition to IL-17, IL-22. In the current issue of the European Journal of Immunology, an article by Larsen et al. (Eur. J. Immunol. 2011. 41: 2596-2605) provides evidence that human T helper cells, like murine cells, can also express IL-22 in the absence of the other T helper cell signature cytokines. Moreover, they show that these IL-22-producing cells, namely Th22 cells, can be found in the skin of psoriasis patients, where they might contribute to the pathogenesis of this inflammatory skin disease. Finally, they show that,…
T cell directives for transcriptional regulation in asthma.
2003
Allergic asthma frequently starts in childhood, and environmental factors such as viruses, allergens and occupational exposure can regulate the evolution of the disease. The development of allergen-specific Th2 lymphocytes represents the triggering event for the recruitment and activation of IgE-producing B cells and fibroblasts, followed by the release of soluble factors, thus giving rise to the inflammatory reaction observed in this disease. GATA-3 was identified as a cell lineage-specific factor selectively expressed and activated in the Th2 lineage as a consequence of STAT-6 activation. However, recent literature indicates that blockade of CTLA-4-directed inhibitory signals is sufficien…