Search results for "Lymphocyte"
showing 10 items of 2280 documents
Reconstitution of CD8 T cells is essential for the prevention of multiple-organ cytomegalovirus histopathology after bone marrow transplantation.
1998
Cytomegalovirus (CMV) infection in the period of temporary immunodeficiency after haematoablative treatment and bone marrow transplantation (BMT) is associated with a risk of graft failure and multiple-organ CMV disease. The efficacy of immune system reconstitution is decisive for the prevention of CMV pathogenesis after BMT. Previous data in murine model systems have documented a redundancy in the immune effector mechanisms controlling CMV. CD8 T cells proved to be relevant but not irreplaceable as antiviral effectors. Specifically, in a state of long-term in vivo depletion of the CD8 T-cell subset, CD4 T cells were educed to become deputy effectors controlling CMV by a mechanism involving…
In vitro model for the activation of CD4 and CD8 T cell receptors.
2008
Previously, most models that sought to explain the misregulation of immune cell function assumed molecular similarities between the disease-causing pathogens and the host's proteins. In recent time several different models have been proposed and in this study, these concepts are compared to a new hypothesis proposing another explanation for this immune dysregulation: the possibility that the mislocalization of proteins may be responsible for autoimmune activity. Based on this hypothesis, proteins are recognized as self or non-self depending on where they appear in sufficiently high concentrations. To examine this new idea, the intracellular human proteins beta-actin, GAPDH, and hemoglobin a…
CD8+ cytotoxic T lymphocytes isolated from allogeneic healthy donors recognize HLA class Ia/Ib–associated renal carcinoma antigens with ubiquitous or…
2004
AbstractAllogeneic hematopoietic stem cell transplantation can induce considerable tumor remissions in metastatic renal-cell carcinoma (RCC) patients. The precise effector mechanisms mediating these graft-versus-tumor reactions are unknown. We studied RCC-directed CD8+ T-cell responses in blood lymphocytes of healthy individuals matched with established RCC cell lines for HLA-class I. In 21 of 22 allogeneic mixed lymphocyte/tumor-cell cultures (MLTCs), RCC-reactive cytotoxic T-lymphocytes (CTLs) were readily obtained. From MLTCs, 121 CD8+ CTL clones with memory phenotype were isolated. Their anti–RCC reactivity was restricted by multiple classical HLA-Ia molecules, in particular by HLA-A2, …
Uptake and presentation of exogenous antigen and presentation of endogenously produced antigen by skin dendritic cells represent equivalent pathways …
2008
Gene gun-mediated biolistic DNA vaccination with beta-galactosidase (betaGal)-encoding plasmid vectors efficiently modulated antigen-induced immune responses in an animal model of type I allergy, including the inhibition of immunoglobulin E (IgE) production. Here we show that CD4(+) as well as CD8(+) T cells from mice biolistically transfected with a plasmid encoding betaGal under the control of the fascin promoter (pFascin-betaGal) are capable of inhibiting betaGal-specific IgE production after adoptive transfer into naïve recipients. Moreover, suppression of IgE production was dependent on interferon (IFN)-gamma. To analyse the modalities of activation of CD4(+) and CD8(+) T cells regardi…
Clonal analysis of human T lymphocytes infiltrating the liver in chronic active hepatitis B and primary biliary cirrhosis
1988
Human T lymphocytes infiltrating the liver in chronic active hepatitis B (CAH-B) and primary biliary cirrhosis were isolated from liver biopsy cores, cloned by limiting dilution technique and expanded in vitro. Phenotypic and functional analysis demonstrates that this tissue infiltrate represents a heterogeneous cell population. However, when compared to peripheral blood lymphocytes of the same patients, a marked enrichment for T8+ cytotoxic T cells was found to exist at a local site in both types of chronic liver disease. These data provide support for the notion that liver cell injury in CAH-B and PBC may be mediated by a common immunologic mechanism likely executed by cells of the T line…
Perforin deficiency attenuates inflammation and tumor growth in colitis-associated cancer
2010
Background: Patients with inflammatory bowel disease (IBD) have a markedly increased risk to develop colon cancer, but there are only limited data about the host antitumor response in such colitis-associated cancer. In the present study we aimed at assessing the role of perforin-dependent effector mechanisms in the immune response in a murine model of colitis-associated colon cancer. Methods: Wildtype and perforin-deficient mice were analyzed in a mouse model of colitis-associated colon cancer using azoxymethane (AOM) and dextran sodium sulfate (DSS). Results: Tumors of wildtype mice showed infiltration of CD4+, CD8+ T cells, natural killer (NK) cells, high numbers of apoptotic cells, and e…
Characterization of lung γδ T cells following intranasal infection with Mycobacterium bovis bacillus Calmette-Guérin
2002
The lungs are considered to have an impaired capacity to contain infection by pathogenic mycobacteria, even in the presence of effective systemic immunity. In an attempt to understand the underlying cellular mechanisms, we characterized the gammadelta T cell population following intranasal infection with Mycobacterium bovis bacillus Calmette-Guerin (BCG). The peak of gammadelta T cell expansion at 7 days postinfection preceded the 30 day peak of alphabeta T cell expansion and bacterial count. The expanded population of gammadelta T cells in the lungs of BCG-infected mice represents an expansion of the resident Vgamma2 T cell subset as well as an influx of Vgamma1 and of four different Vdelt…
Mage-3 and influenza-matrix peptide-specific cytotoxic T cells are inducible in terminal stage HLA-A2.1+ melanoma patients by mature monocyte-derived…
2000
Abstract Dendritic cell (DC) vaccination, albeit still in an early stage, is a promising strategy to induce immunity to cancer. We explored whether DC can expand Ag-specific CD8+ T cells even in far-advanced stage IV melanoma patients. We found that three to five biweekly vaccinations of mature, monocyte-derived DC (three vaccinations of 6 × 106 s.c. followed by two i.v. ones of 6 and 12 × 106, respectively) pulsed with Mage-3A2.1 tumor and influenza matrix A2.1-positive control peptides as well as the recall Ag tetanus toxoid (in three of eight patients) generated in all eight patients Ag-specific effector CD8+ T cells that were detectable in blood directly ex vivo. This is the first time …
Oral delivery of homologous and heterologous strains of rotavirus to BALB/c mice induces the same profile of cytokine production by spleen cells.
1998
Abstract In this work, we wanted to clarify if differences in antibody (Ab) and particularly in secretory immunoglobulin A (IgA) responses following homologous or heterologous rotavirus infection could be explained by different priming of specific T helper (Th) cells. We compared the Ab responses from suckling BALB/c mice orally inoculated with either a heterologous simian (SA11) or bovine (RF) rotavirus or a homologous murine rotavirus (EHP w ), as well as the profile of cytokines produced by spleen cells after in vitro restimulation. Oral inoculation of EHP w and SA11 induced a similar pattern of Ab with mucosal and serum IgA associated with serum IgG with equal levels of IgG1 and IgG2a, …
Stochastic Episodes of Latent Cytomegalovirus Transcription Drive CD8 T-Cell “Memory Inflation” and Avoid Immune Evasion
2021
Acute infection with murine cytomegalovirus (mCMV) is controlled by CD8+ T cells and develops into a state of latent infection, referred to as latency, which is defined by lifelong maintenance of viral genomes but absence of infectious virus in latently infected cell types. Latency is associated with an increase in numbers of viral epitope-specific CD8+ T cells over time, a phenomenon known as “memory inflation” (MI). The “inflationary” subset of CD8+ T cells has been phenotyped as KLRG1+CD62L- effector-memory T cells (iTEM). It is agreed upon that proliferation of iTEM requires repeated episodes of antigen presentation, which implies that antigen-encoding viral genes must be transcribed du…