Search results for "immunophenotyping"
showing 10 items of 175 documents
High-throughput elucidation of thrombus formation reveals sources of platelet function variability
2019
In combination with microspotting, whole-blood microfluidics can provide high-throughput information on multiple platelet functions in thrombus formation. Based on assessment of the inter-and intra-subject variability in parameters of microspot-based thrombus formation, we aimed to determine the platelet factors contributing to this variation. Blood samples from 94 genotyped healthy subjects were analyzed for conventional platelet phenotyping: i.e. hematologic parameters, platelet glycoprotein (GP) expression levels and activation markers (24 parameters). Furthermore, platelets were activated by ADP, CRP-XL or TRAP. Parallel samples were investigated for whole-blood thrombus formation (6 mi…
Pertussis-specific cell-mediated immunity in infants after vaccination with a tricomponent acellular pertussis vaccine.
1996
The aim of this study was to investigate pertussis-specific cell-mediated immunity in infants vaccinated with a tricomponent acellular vaccine. Infants were investigated during a primary vaccination schedule from the third month of life to the sixth month as well as before and after a booster at 15 to 24 months. This is the first report of specific cell-mediated immune responses to pertussis-related antigens in infants below the age of 12 months. Our data show that the vaccine induces T-cell responses specific for the vaccine components, detoxified pertussis toxin, filamentous hemagglutinin, and pertactin, that increase progressively over the course of the vaccination schedule. In contrast …
Activation of phenotypically heterogeneous murine T cell receptor gamma delta + dendritic epidermal T cells by self-antigen(s).
1995
Adult murine epidermis contains a population of Thy-1+, CD45+, CD3+, CD4- and CD8- in situ primarily T cell receptor (TCR) V gamma 3+/V delta 1+ dendritic epidermal T cells (DETC). In the present study, cell surface phenotypes as well as functional properties of DETC were characterized by using in vitro mitogen-stimulated short-term- (10 days) and cloned long-term-cultured (1 year) DETC lines. Phenotypic characterization revealed that80% of the short-term-cultured cells were routinely TCR gamma delta +, CD4-, CD8-. The majority expressed the V gamma 3 TCR. Seventy-five percent of the lines contained detectable numbers of V gamma 2+ (5-7%) and V gamma 2-3- cells (2-3%). Four different types …
Human Haemato-Endothelial Precursors: Cord Blood CD34+ Cells Produce Haemogenic Endothelium
2012
Embryologic and genetic evidence suggest a common origin of haematopoietic and endothelial lineages. In the murine embryo, recent studies indicate the presence of haemogenic endothelium and of a common haemato-endothelial precursor, the haemangioblast. Conversely, so far, little evidence supports the presence of haemogenic endothelium and haemangioblasts in later stages of development. Our studies indicate that human cord blood haematopoietic progenitors (CD34+45+144-), triggered by murine hepatocyte conditioned medium, differentiate into adherent proliferating endothelial precursors (CD144+CD105+CD146+CD31+CD45-) capable of functioning as haemogenic endothelium. These cells, proven to give…
The gp130-stimulating designer cytokine hyper-IL-6 promotes the expansion of human hematopoietic progenitor cells capable to differentiate into funct…
2000
Abstract Objective . Hyper-IL-6, a fusion protein of interleukin-6 and its specific receptor, together with stem cell factor leads to the proliferation of primitive hematopoietic progenitor cells. Based on these findings, the current study examined whether hyper-IL-6 promotes the growth of precursor cells that can be further differentiated into dendritic cells in the presence of additional cytokines. Methods . Dendritic cell cultures were generated from CD34 + hematopoietic progenitor cells derived either from bone marrow or from peripheral blood. CD34 + cells were cultured in the presence of cytokines for 2 weeks and then used for phenotyping and T-cell stimulation assays. Results . Hyper-…
Measurement of T Cell Activation After 16‐hr In Vitro Stimulation with Concanavalin A
2010
A flow cytometry assay that can be used to directly determine the proportion of activated T lymphocytes in human whole blood samples after stimulation with concanavalin A is presented here. Human whole blood is incubated with fluorescently labeled antibodies (against CD3, CD4, CD8, and CD69), erythrocytes are then lysed, and the samples are analyzed using a flow cytometer. The assay presented is able to differentiate between CD4+ and CD8+ T lymphocytes. Thus, it is possible to quantify both lymphocyte populations in parallel, as well as the respective proportions of activated T lymphocytes, all from one sample. An additional advantage of this assay is that it was developed to assay whole bl…
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…
Induction of Interleukin 10–Producing, Nonproliferating Cd4+ T Cells with Regulatory Properties by Repetitive Stimulation with Allogeneic Immature Hu…
2000
The functional properties of dendritic cells (DCs) are strictly dependent on their maturational state. To analyze the influence of the maturational state of DCs on priming and differentiation of T cells, immature CD83− and mature CD83+ human DCs were used for stimulation of naive, allogeneic CD4+ T cells. Repetitive stimulation with mature DCs resulted in a strong expansion of alloreactive T cells and the exclusive development of T helper type 1 (Th1) cells. In contrast, after repetitive stimulation with immature DCs the alloreactive T cells showed an irreversibly inhibited proliferation that could not be restored by restimulation with mature DCs or peripheral blood mononuclear cells, or by…
Effect of female genital schistosomiasis and anti-schistosomal treatment on monocytes, CD4+ T-cells and CCR5 expression in the female genital tract
2014
Published version of an article from the journal: PLoS One. Also available from the publisher: http://dx.doi.org/10.1371/journal.pone.0098593 BACKGROUND: Schistosoma haematobium is a waterborne parasite that may cause female genital schistosomiasis (FGS), characterized by genital mucosal lesions. There is clinical and epidemiological evidence for a relationship between FGS and HIV. We investigated the impact of FGS on HIV target cell density and expression of the HIV co-receptor CCR5 in blood and cervical cytobrush samples. Furthermore we evaluated the effect of anti-schistosomal treatment on these cell populations. DESIGN: The study followed a case-control design with post treatment follow…
Evidence of alloreactive T lymphocytes in fetal liver: implications for fetal hematopoietic stem cell transplantation
2000
The use of hematopoietic stem cells for in utero transplantation to create permanent hematochimerism represents a new concept in fetal therapy, although this approach has provided heterogeneous results. In this paper we have undertaken molecular, phenotypic and functional studies aimed at identifying the presence of fully competent T lymphocytes in samples of fetal livers and cord blood. We found mature VDJ TCR beta chain transcripts in fetal liver cells taken from 7 to 16 weeks of gestation and a similar pattern was detected in cord blood cells sampled from 13.5 to 20.5 weeks of gestation. A Vbeta8 gene sequence comparable to that detected in adult PBMC was found in fetal liver samples at …