Search results for "N-2"
showing 10 items of 1881 documents
Assessment of local cellular immunity in lung cancer by bronchoalveolar lavage.
1990
Small cell lung cancer (SCLC) is the most malignant of the pulmonary neoplasms and is associated with a poor local cellular immune response. 16 patients with non small cell lung cancer (NSCLC) and 11 patients with SCLC underwent bronchoalveolar lavage (BAL) in the lung which harbored the tumor in order to investigate the lymphocyte surface antigens utilizing the immunoperoxidase technique. Analysis of blood lymphocytes was performed in parallel. 8 patients with previous sarcoidosis in complete remission who underwent BAL and 10 normal blood donors served as controls. Among blood lymphocytes the CD3+, CD4+ and CD16+ cell populations were elevated significantly and the T4/T8 ratio was elevate…
Regulatory T Cells Accumulate and Proliferate in the Ischemic Hemisphere for up to 30 Days after MCAO
2012
Local and peripheral immune responses are activated after ischemic stroke. In our present study, we investigated the temporal distribution, location, induction, and function of regulatory T cells (Tregs) and the possible involvement of microglia, macrophages, and dendritic cells after middle cerebral artery occlusion (MCAO). C57BL/6J and Foxp3EGFP transgenic mice were subjected to 30 minutes MCAO. On days 7, 14, and 30 after MCAO, Tregs and antigen presenting cells were analyzed using fluorescence activated cell sorting multicolor staining and immunohistochemistry. A strong accumulation of Tregs was observed on days 14 and 30 in the ischemic hemisphere accompanied by the elevated presence …
Regulatory activity of human CD4 CD25 T cells depends on allergen concentration, type of allergen and atopy status of the donor.
2005
Regulatory CD4+ CD25+ FoxP3-positive T cells (Treg) are functional in most atopic patients with allergic rhinitis and are able to inhibit T helper type 1 (Th1) and Th2 cytokine production of CD4+ CD25- T cells. This study was designed to analyse the following additional aspects: influence of allergen concentration, influence of the type of allergen, and influence of the atopy status of the donor on the strength of the regulatory activity. CD4+ CD25- T cells from healthy non-atopic controls or from grass-pollen-allergic or wasp-venom-allergic donors were stimulated alone or in the presence of Treg with autologous mature monocyte-derived dendritic cells which were pulsed with different concen…
The Regulatory T Cell Family: Distinct Subsets and their Interrelations
2003
The immune system, a highly effective and dynamic cellular network, protects a host from pathogens. Therefore, the immune system must distinguish self from nonself structures, but also between harmful and innocuous foreign Ags to prevent nonessential and self-destructive immune responses. The
Direct Cellular Interaction with Activated CD4+T Cells Overcomes Hyporesponsiveness of B-Cell Chronic Lymphocytic Leukemiain Vitro
1998
The proliferative response of clonal B cells from patients with chronic lymphocytic leukemia (B-CLL) is drastically reduced compared to normal B lymphocytes stimulated via the B cell antigen receptor complex or by CD40 ligation. In the present study we demonstrate that hyporesponsiveness of CLL-B cells can be overcome by stimulatory pathways mediated by activated CD4(+) T cells. In contrast to CD40 ligation, costimulation with activated T cells promotes a proliferative response in CLL-B cells identical to that in normal B cells. Furthermore, coculture with activated T cells improved survival of CLL-B cells in vitro. Differentiation of CLL-B cells into IgM producing cells was promoted, as we…
Cutting Edge: TGF-β Induces a Regulatory Phenotype in CD4+CD25− T Cells through Foxp3 Induction and Down-Regulation of Smad7
2004
Abstract CD4+CD25+ regulatory cells are a subpopulation of T lymphocytes of thymic origin. However, recent data suggest an alternative commitment of regulatory T cells in the periphery, although the precise mechanism is unknown. In the present work, we demonstrate that TGF-β is able to induce Foxp3 expression and subsequently a regulatory phenotype in CD4+CD25− peripheral murine T cells. Similarly, TGF-β induced Foxp3 in human CD4+CD25− T cells. Moreover, we show that the inhibitory Smad7 protein that is normally induced by TGF-β and limits TGF-β signaling, is strongly down-regulated by Foxp3 at the transcriptional level. Foxp3-mediated down-regulation of Smad7 subsequently rendered CD4+CD2…
Differential Regulatory Capacity of CD25+ T Regulatory Cells and Preactivated CD25+ T Regulatory Cells on Development, Functional Activation, and Pro…
2004
Abstract CD25+ T regulatory (Treg) cells play a central role regarding the maintenance of peripheral tolerance via suppression of autoaggressive CD4+ T cells, CD8+ T cells, and Th1 cells. In this study we demonstrate that CD25+ Treg cells can also suppress the differentiation of murine conventional CD4+ T cells toward Th2 cells in a contact-dependent manner. However, the cytokine production and proliferation of established Th2 cells could not be inhibited by freshly isolated CD25+ Treg cells, whereas a strong inhibition of differentiated Th2 cells by in vitro preactivated CD25+ Treg cells could be observed. Inhibition of both conventional CD4+ T cells and Th2 cells is accompanied by a stron…
Nitric oxide enhances Th9 cell differentiation and airway inflammation
2014
International audience; Th9 cells protect hosts against helminthic infection but also mediate allergic disease. Here we show that nitric oxide (NO) promotes Th9 cell polarization of murine and human CD4(+) T cells. NO de-represses the tumour suppressor gene p53 via nitrosylation of Mdm2. NO also increases p53-mediated IL-2 production, STAT5 phosphorylation and IRF4 expression, all essential for Th9 polarization. NO also increases the expression of TGFβR and IL-4R, pivotal to Th9 polarization. OVA-sensitized mice treated with an NO donor developed more severe airway inflammation. Transferred Th9 cells induced airway inflammation, which was exacerbated by NO and blocked by anti-IL-9 antibody.…
Murine liver antigen presenting cells control suppressor activity of CD4+CD25+ regulatory T cells.
2005
CD4(+)CD25(+) regulatory T cells (Treg) are important mediators of peripheral immune tolerance; however, whether Treg participate also in hepatic immune tolerance is not clear. Therefore, we tested the potential of Treg to suppress stimulation of CD4(+) T cells by liver sinusoidal endothelial cells (LSEC), Kupffer cells (KC), or hepatocytes. In the absence of Treg, all 3 types of liver cells could stimulate CD4(+) T cell proliferation; in the presence of Treg, however, CD4(+) T cell proliferation was suppressed. Interaction with KC even stimulated the expansion of the Treg population; LSEC or hepatocytes, in contrast, could not induce proliferation of Treg. Because liver inflammation can be…
Epicutaneous and Oral Low-Zone Tolerance Protects from Colitis in Mice
2016
Tolerance to environmental antigens that encounter the organism at interfaces like skin or gut prevents deleterious systemic immune responses. The aim of this study was to analyze whether and how low doses of haptens, by entry through the skin or gastrointestinal tract, affect the outcome of the predominantly Th1/Th17-mediated 2,4,6-trinitro-benzenesulfonic acid-induced colitis, which mimics an autoimmune bowl disease in man. Epicutaneous and oral applications of low doses of the allergen resulted in the induction of low-zone tolerance (LZT) and protected from colitis development, demonstrated by a significantly reduced inflammatory response of the gut in vivo. In line with this observation…