Search results for "t-lymphocyte"
showing 10 items of 1502 documents
Regulatory T cell-derived adenosine induces dendritic cell migration through the Epac-Rap1 pathway.
2014
Abstract Dendritic cells (DC) are one target for immune suppression by regulatory T cells (Treg), because their interaction results in reduced T cell stimulatory capacity and secretion of inhibitory cytokines in DC. We show that DC in the presence of Treg are more mobile as compared with cocultures with conventional CD4+ T cells and form DC–Treg aggregates within 2 h of culture. The migration of DC was specifically directed toward Treg, as Treg, but not CD4+ T cells, attracted DC in Boyden chambers. Treg deficient for the ectonucleotidase CD39 were unable to attract DC. Likewise, addition of antagonists for A2A adenosine receptors abolished the formation of DC–Treg clusters, indicating a ro…
Aminobisphosphonates as new weapons for gammadelta T Cell-based immunotherapy of cancer.
2008
BACKGROUND: Activated V gamma 9 V delta 2 T cells are able to kill most tumour cells because of recognition by T cell receptor and natural killer receptors. OBJECTIVE: We discuss the possibility that the intentional activation of gammadelta T cells in vivo by aminobisphosphonates may represent a promising target for the design of novel and highly innovative immunotherapy in cancer patients. METHODS: The antitumoral effects of gammadelta T cells both in vitro and in vivo have been demonstrated suggesting a new therapeutic approach for translation into the clinical setting. RESULTS/CONCLUSION: V gamma 9 V delta 2 T lymphocytes represent a particularly interesting target for immunotherapeutic …
The transcription factor NFATc2 controls IL-6–dependent T cell activation in experimental colitis
2008
The nuclear factor of activated T cells (NFAT) family of transcription factors controls calcium signaling in T lymphocytes. In this study, we have identified a crucial regulatory role of the transcription factor NFATc2 in T cell–dependent experimental colitis. Similar to ulcerative colitis in humans, the expression of NFATc2 was up-regulated in oxazolone-induced chronic intestinal inflammation. Furthermore, NFATc2 deficiency suppressed colitis induced by oxazolone administration. This finding was associated with enhanced T cell apoptosis in the lamina propria and strikingly reduced production of IL-6, -13, and -17 by mucosal T lymphocytes. Further studies using knockout mice showed that IL-…
Induction of the anti-ergotypic response.
1993
The injection of syngeneic activated T cells into rodents can induce a T cell response against activation markers of the T cells, ergotopes. The responding anti-ergotypic T cells have been shown to suppress experimental autoimmune encephalomyelitis (EAE). This paper reports the characteristics of the anti-ergotypic response. It was found that irradiated activated T cells were as good as untreated living activated T cells in inducing anti-ergotypic cells in vivo. Glutardialdehyde-fixed (0.3%) cells were poor stimulators in vivo and non-stimulatory in vitro. Dilution of glutardialdehyde to 0.003% before fixation preserved the stimulatory capacity in vitro. Fixation or irradiation of T cells a…
Genetic proof for the transient nature of the Th17 phenotype
2010
IL-17-producing CD4(+) T cells (Th17) have been classified as a new T helper cell subset. Using an IL-17 fate mapping mouse strain, which genetically fixes the memory of IL-17 expression, we demonstrate that IL-17A/F-expressing T helper cells generated either in vitro or in vivo are not a stable T-cell subset. Upon adoptive transfer of IL-17F-reporter-positive Th17 cells to RAG-deficient or WT animals, encephalitogenic Th17 cells partially lose IL-17 expression and upregulate IFN-γ. Additionally, we show that Th1 cells can convert in vivo to IL-17A/IFN-γ-coexpressing cells in the mesenteric lymph nodes (mLN). Our data classify IL-17A and IL-17F as cytokines produced transiently in response …
Lack of requirement for CD8+ cells in recovery from and resistance to experimental autoimmune encephalomyelitis.
1995
Abstract Experimental autoimmune encephalomyelitis (EAE) is a model of T-cell mediated autoimmune disease. Active disease is mediated by myelin basic protein specific CD4+T-cells, whose adoptive transfer can also induce passive disease. In the Lewis rat EAE is a transient disease inducing lasting resistance to rechallenge. The mechanisms of recovery and resistance are poorly understood. CD8+suppressor T-cells have mostly been thought to be central, especially in resistance to reinduction of the disease. In this study we showed by complete depletion of CD8+cells that this subset does not influence either recovery or resistance to EAE in the Lewis rat. This was further confirmed by depleting …
T cells expressing a chimeric antigen receptor that binds hepatitis B virus envelope proteins control virus replication in mice.
2013
Background & Aims Antiviral agents suppress hepatitis B virus (HBV) replication but do not clear the infection. A strong effector T-cell response is required to eradicate HBV, but this does not occur in patients with chronic infection. T cells might be directed toward virus-infected cells by expressing HBV-specific receptors and thereby clear HBV and help to prevent development of liver cancer. In mice, we studied whether redirected T cells can engraft after adoptive transfer, without prior T-cell depletion, and whether the large amounts of circulating viral antigens inactivate the transferred T cells or lead to uncontrolled immune-mediated damage. Methods CD8 + T cells were isolated from m…
Cytomegalovirus Misleads Its Host by Priming of CD8 T Cells Specific for an Epitope Not Presented in Infected Tissues
2003
Cytomegaloviruses (CMVs) code for several proteins that inhibit the presentation of antigenic peptides to CD8 T cells. Although the molecular mechanisms of CMV interference with the major histocompatibility complex class I pathway are long understood, surprisingly little evidence exists to support a role in vivo. Here we document the first example of the presentation of an antigenic peptide being blocked by a CMV immune evasion protein in organs relevant to CMV disease. Although this Db-restricted peptide, which is derived from the antiapoptotic protein M45 of murine CMV (mCMV), is classified as an immunodominant peptide based on response magnitude and long-term memory, adoptive transfer of…
Contribution of IL-17-producing {gamma}{delta} T cells to the efficacy of anticancer chemotherapy.
2011
IL-17 production by γδ T cells is required for tumor cell infiltration by IFN-γ–producing CD8+ T cells and inhibition of tumor growth in response to anthracyclines.
Stat3 and Gfi-1 Transcription Factors Control Th17 Cell Immunosuppressive Activity via the Regulation of Ectonucleotidase Expression
2012
International audience; Although Th17 cells are known to promote tissue inflammation and autoimmunity, their role during cancer progression remains elusive. Here, we showed that in vitro Th17 cells generated with the cytokines IL-6 and TGF-β expressed CD39 and CD73 ectonucleotidases, leading to adenosine release and the subsequent suppression of CD4(+) and CD8(+) T cell effector functions. The IL-6-mediated activation of the transcription factor Stat3 and the TGF-β-driven downregulation of Gfi-1 transcription factor were both essential for the expression of ectonucleotidases during Th17 cell differentiation. Stat3 supported whereas Gfi-1 repressed CD39 and CD73 expression by binding to thei…