Search results for "Clone Cell"
showing 10 items of 87 documents
Fine specificity and cytolytic activity of continuously growing alloreactive cytotoxic T lymphocyte clones.
1980
The role of Lyt 1+ T-cell-derived secondard CTL inducing factor allowed the cloning of alloreactive cytotoxic T lymphocytes (CTL) by the limiting dilution approach. Several monoclonal cell lines were established in vitro. The lytic activity of some of the cell lines exceeded that of CTL from bulk cultures; that is, 50% of the target cells were lysed at an effector to target cell ratio of 0.04:1. The fine specificity of individual CTL clones is discussed.
T lymphocyte control of autoreactivity: analysis with human T cell clones and limiting dilution culture
1986
To investigate cellular mechanisms controlling activated autoreactive T lymphocytes, a limiting dilution system was established employing cloned autoreactive major his-tocompatibility complex class II specific lymphocytes (a2/7) as stimulator cells for autologous peripheral blood mononuclear cells. At low responder/stimulator ratios, cytotoxic effector cells were generated capable of lysing clone a2/7. Importantly, within the population of cells mediating autocytotoxic effector function, differential specificities were found to exist. The generation of such autocytotoxic T lymphocytes appears to be inhibited by an additional population of cells circulating at lower frequency suggesting that…
Persistent inflammation alters the function of the endogenous brain stem cell compartment
2008
Endogenous neural stem/precursor cells (NPCs) are considered a functional reservoir for promoting tissue homeostasis and repair after injury, therefore regenerative strategies that mobilize these cells have recently been proposed. Despite evidence of increased neurogenesis upon acute inflammatory insults (e.g. ischaemic stroke), the plasticity of the endogenous brain stem cell compartment in chronic CNS inflammatory disorders remains poorly characterized. Here we show that persistent brain inflammation, induced by immune cells targeting myelin, extensively alters the proliferative and migratory properties of subventricular zone (SVZ)-resident NPCs in vivo leading to significant accumulation…
Humoral Mechanisms in T cell Vaccination: Induction and Functional Characterization of Anti-lymphocytic Autoantibodies
1997
T cell vaccination, the application of syngeneic attenuated T cells, has been shown to prevent effectively and treat experimental autoimmune diseases, but its mechanisms of action are poorly understood. Here we present data on the induction of a humoral anti-T cell response by T cell vaccination, capable of strongly inhibiting T cell proliferation and of ameliorating experimental autoimmune disease. T cell vaccination in the Lewis rat induced autoantibodies reactive with several syngeneic T cell proteins. These autoantibodies were not detectable in normal Lewis sera as assessed by immunoblotting and flow cytometry with intact syngeneic T cells. The autoantibody reactivity was not restricted…
Lymphokine profile and activation pattern of two unrelated antigen- or idiotype-specific T suppressor cell clones.
1992
Two T suppressor (Ts) clones of different specificity have been analyzed for their lymphokine spectrum. BVI/5 is an I-Ek-restricted bovine serum albumin (BSA)-specific Ts cell clone from a CBA/J mouse tolerized by low doses of BSA. It affects directly or indirectly the function of BSA-specific T helper (Th) cells. The Ts cell clone 178-4 from a BALB/c mouse is I-Ed restricted and recognizes the public J558 Id on B cells. It prevents alpha(1----3)dextran B 1355S (Dex)-specific IgG antibody production and drives Dex-specific J558 idiotype-bearing B cells into an anergic B IgG memory cell state. Both Ts cell clones thus cause specific suppression, yet in different experimental systems using di…
Minimal peripheral blood cells carrying clonal markers of b cell disorders: Evidence for monoclonality of circulating lymphocytes in patients with mu…
1989
Peripheral blood lymphocytes (PBL) of 20 patients with multiple myeloma (MM) were assayed for clonality by Southern blot and cell surface marker analysis. Eight samples showed monoclonal origin of circulating lymphocytes by demonstrating rearrangements of the heavy chain immunoglobulin gene (IgH). In selected experiments, comparison of IgH rearrangements of bone marrow plasma cells and peripheral blood-derived mononuclear cells, highly enriched for B lymphocytes, proved to be identical. However, monoclonal circulating cells could not be detected in samples with rearranged IgH genes by surface marker phenotyping using one-color immunofluorescence analysis and a panel of monoclonal and polycl…
Induced Pluripotent Mesenchymal Stromal Cell Clones Retain Donor-derived Differences in DNA Methylation Profiles
2012
Reprogramming of somatic cells into induced pluripotent stem cells (iPSCs) is an epigenetic phenomenon. It has been suggested that iPSC retain some tissue-specific memory whereas little is known about interindividual epigenetic variation. We have reprogrammed mesenchymal stromal cells from human bone marrow (iP-MSC) and compared their DNA methylation profiles with initial MSC and embryonic stem cells (ESCs) using high-density DNA methylation arrays covering more than 450,000 CpG sites. Overall, DNA methylation patterns of iP-MSC and ESC were similar whereas some CpG sites revealed highly significant differences, which were not related to parental MSC. Furthermore, hypermethylation in iP-MSC…
Estimation of the frequency of self-reactive T cells in health and inflammatory diseases by limiting dilution analysis and single cell cloning.
1996
Autoreactive T cells have recently been detected not only in autoimmune diseases but also in healthy individuals, but their frequency is thought to be low. The aim of our study was to estimate the frequency of self-reactive T cells by using limiting dilution analyses of peripheral blood lymphocytes. Assessment of self-reactivity in this study was defined as T-cell proliferation to autologous non-T cells in the absence of foreign antigens. When culture conditions were optimized by adding interleukin 2, healthy individuals showed a frequency of self-reactive T cells ranging from 1/60 to 1/600. These results were confirmed by using unseparated peripheral blood leukocytes or Epstein-Barr virus …
Cloned T helper cells reverting to a resting state develop increasing sensitivity in their antigen-mediated interaction with accessory cells.
1988
A cloned murine T cell line, KIII5, specific for the polypeptide poly-L(Tyr,Glu)-poly-D,L-Ala--poly-L-Lys [(T,G)-A--L] was compared at different stages after antigenic stimulation with respect to the conditions required for the reinduction of growth by varying concentrations of antigen presented on different types of accessory cells (AC). We show that the dose of antigen necessary for inducing half maximal proliferation in the presence of splenic AC shifts to considerably lower concentrations when the T cell blasts revert to a resting state (100 micrograms/ml on day 7 to 10 micrograms/ml on day 21-35). During the same time period the expression of interleukin 2 (IL2) receptor and the reacti…
Functionally Active T Cell Receptor/CD3 Complexes Are Present at the Surface of Cloned Cytotoxic T Cells without Fluorescence-Immunological Detectabi…
1996
The cytotoxic T cell clone 10BK.1 is activated in response to the ovalbumin peptide OVA257-264 in a major histocompatibility complex class I-restricted manner. Following activation 10BK.1 cells proliferate, secrete lymphokines, and kill syn- and allogeneic target cells. Using immunofluorescence analysis we detected CD8, LFA-1, and ICAM-1 on the surface of 10BK.1 cells, but no CD3 or T cell receptor (TCR). In contrast, the proliferative response of 10BK.1 cells to antigen was efficiently blocked by soluble antibodies directed at CD3 epsilon or TCR alpha beta, but not by antibodies directed at TCR gamma delta. In addition, lysis of target cells was blocked by F(ab')2 fragments of antibodies d…