Search results for " t-lymphocytes"
showing 10 items of 495 documents
Cerebrospinal fluid T-regulatory cells recognize Borrelia burgdorferi NAPA in chronic Lyme borreliosis.
2013
The NapA protein of B. burgdorferi is essential for the persistence of spirochetes in ticks. One of the most intriguing aspects of NapA is its potential to interfere with the host immune system. Here, we investigated the role of the acquired immune responses induced by NapA in the cerebrospinal fluids (CSF) of patients with chronic Lyme borreliosis. We evaluated the cytokine profile induced in microglia cells and CSF T cells following NapA stimulation. We report here that NapA induced a regulatory T (Treg) response in the CSF of patients with chronic Lyme borreliosis and it is able to expand this suppressive response by promoting the production of TGF-β and IL-10 by microglia cells. Collect…
Intracellular Cytokine Staining and Flow Cytometry: Considerations for Application in Clinical Trials of Novel Tuberculosis Vaccines.
2015
Intracellular cytokine staining combined with flow cytometry is one of a number of assays designed to assess T-cell immune responses. It has the specific advantage of enabling the simultaneous assessment of multiple phenotypic, differentiation and functional parameters pertaining to responding T-cells, most notably, the expression of multiple effector cytokines. These attributes make the technique particularly suitable for the assessment of T-cell immune responses induced by novel tuberculosis vaccines in clinical trials. However, depending upon the particular nature of a given vaccine and trial setting, there are approaches that may be taken at different stages of the assay that are more s…
Prophylactic transfer of CD8-depleted donor lymphocytes after T-cell–depleted reduced-intensity transplantation
2006
AbstractAllogeneic hematopoietic stem cell transplantation (SCT) regimens incorporating the lymphocytotoxic CD52 antibody alemtuzumab demonstrate efficient engraftment and reduced graft-versus-host disease (GVHD). However, these protocols substantially impair posttransplantation antiviral and antitumor immunity. To accelerate immune reconstitution after alemtuzumab-based reduced-intensity SCT, we administered prophylactic CD8-depleted donor lymphocyte infusions (DLIs) starting on days 60 and 120 after transplantation. DLIs were processed in an immunomagnetic good manufacturing practice depletion procedure resulting in a 2.5- to 6-log reduction in CD8 T cells. Of 23 high-risk patients with h…
Genetic variability of hepatitis C virus non-structural protein 3 and virus-specific CD8+ response in patients with chronic hepatitis C.
2004
Hepatitis C virus (HCV) variation in specific T-cell epitopes may represent a mechanism of viral persistence in chronic infection. We examined the HCV non-structural protein 3 (NS3), including the immunologically relevant epitopes HCV NS3-2 KLVALGINAV (human leukocyte antigen [HLA]-A2-restricted) and HCV NS3-1391 LIFCHSKKK (HLA-A3-restricted), in 22 HLA-A2+ patients with chronic infection. Significant amino acid variation was found in HCV NS3-2 epitope sequences when compared to the HCV-1 prototype virus. Six of the nine different HCV NS3-2 peptide variants were identified in patients with HCV NS3-2-specific CD8+ cells, detected with an HLA-A2 tetramer made with the HCV-1 prototype peptide.…
Long-Term Human CD34+ Stem Cell-Engrafted Nonobese Diabetic/SCID/IL-2Rγnull Mice Show Impaired CD8+ T Cell Maintenance and a Functional Arrest of Imm…
2010
Abstract Allogeneic hematopoietic stem cell transplantation represents the most effective form of immunotherapy for chemorefractory diseases. However, animal models have been missing that allow evaluation of donor-patient–specific graft-versus-leukemia effects. Thus, we sought to establish a patient-tailored humanized mouse model that would result in long-term engraftment of various lymphocytic lineages and would serve as a donor-specific surrogate. Following transfer of donor-derived peripheral blood stem cells into NOD/SCID/IL-2Rγnull (NSG) mice with supplementation of human IL-7, we could demonstrate robust engraftment and multilineage differentiation comparable to earlier studies using …
The use of computer-assisted video image analysis for the quantification of CD8+ T lymphocytes producing tumor necrosis factor alpha spots in respons…
1997
Enzyme-linked immunospot (ELISPOT) analysis is a sensitive technique for the detection and quantification of single T lymphocytes forming cytokine spots after antigen contact in vitro. Herein computer-assisted video image analysis (CVIA) was applied to automatically determine the number and size of tumor necrosis factor alpha (TNF-alpha) spots formed by single blood-derived CD8+ T cells after contact with peptide-loaded target cells. With CVIA and TNF-alpha ELISPOT analysis we quantified CD8+ T cells responsive to HLA-A2.1-binding tyrosinase and influenza matrix peptides in healthy donors. We followed the course of the virus-specific T cell response in two HLA-A2-positive patients with reac…
The Transcription Factor T-bet Is Induced by IL-15 and Thymic Agonist Selection and Controls CD8αα+ Intraepithelial Lymphocyte Development
2014
Summary CD8αα + intraepithelial lymphocytes (IELs) are instrumental in maintaining the epithelial barrier in the intestine. Similar to natural killer cells and other innate lymphoid cells, CD8αα + IELs constitutively express the T-box transcription factor T-bet. However, the precise role of T-bet for the differentiation or function of IELs is unknown. Here we show that mice genetically deficient for T-bet lacked both TCRαβ + and TCRγδ + CD8αα + IELs and thus are more susceptible to chemically induced colitis. Although T-bet was induced in thymic IEL precursors (IELPs) as a result of agonist selection and interleukin-15 (IL-15) receptor signaling, it was dispensable for the generation of IEL…
T cell killing by tolerogenic dendritic cells protects mice from allergy.
2011
It is well established that allergy development can be prevented by repeated low-dose exposure to contact allergens. Exactly which immune mechanisms are responsible for this so-called low zone tolerance (LZT) is not clear, although CD8⁺ suppressor T cells are known to have a role. Here, we show that TNF released by tolerogenic CD11⁺CD8⁺ DCs located in skin-draining lymph nodes is required and sufficient for development of tolerance to contact allergens in mice. DC-derived TNF protected mice from contact allergy by inducing apoptosis in allergen-specific effector CD8⁺ T cells via TNF receptor 2 but did not contribute to the generation and function of the regulatory T cells associated with LZ…
Proteasome-inhibited dendritic cells demonstrate improved presentation of exogenous synthetic and natural HLA-class I peptide epitopes.
2004
The design and successful clinical implementation of cancer vaccines targeting the induction of T-cell mediated immunity is a rapidly evolving field that is hampered by an empirical selection of antigen and adjuvant. In particular, vaccines using defined tumor-associated peptide epitopes elicit only a restricted T-cell repertoire in a minority of patients. In this regard, vaccines comprising the whole spectrum of antigens presented by individual autologous tumors would be advantageous. In an in vitro model, we evaluated the capacity of naturally processed Epstein-Barr virus-transformed B-lymphoblastoid-cell line (LCL)-derived peptides to activate virus-specific CD8+ T cells of seropositive …
Different response of TH1 cells for stimulation with anti-CD3 antibodies.
1990
In this report, evidence is provided for a further subdivision of CD4+ T helper cell lines. The earlier definition of the TH1 and TH2 subtypes was confirmed by their differential response to interleukin (IL) 1. An additional subdivision of the TH1 subset was revealed when TH1 cell lines were costimulated with anti-CD3 antibodies and IL2. The IL2-induced proliferation of three of the resulting TH1 lines was blocked by anti-CD3 antibodies. By contrast, no such block was observed in a fourth TH1 cell line. In all four lines anti-CD3 triggering caused production of IL2. The block of proliferation was reversed neither by antigen-presenting cells nor by phorbol 12-myristate 13-acetate, a protein …