Search results for " T cell"
showing 10 items of 1161 documents
Cytotoxicity of compounds from Xylopia aethiopica towards multi-factorial drug-resistant cancer cells.
2015
Abstract Introduction Multidrug resistance (MDR) in cancer represent a major hurdle in chemotherapy. Previously, the methanol extract of the medicinal spice Xylopia aethiopica displayed considerable cytotoxicity against multidrug resistant (MDR) cancer cell lines. Methods The present study was designed to assess the cytotoxicity of compounds, 16 α -hydroxy- ent -kauran-19-oic acid ( 2 ), 3,4′,5-trihydroxy-6″,6″-dimethylpyrano[2,3-g]flavone ( 3 ), isotetrandrine ( 5 ) and trans -tiliroside ( 6 ) derived from the methanol crude extract of Xylopia aethiopica against 9 drug-sensitive and -resistant cancer cell lines. The resazurin reduction assay was used to evaluate the cytotoxicity of these c…
Cutting Edge: An IL-17F-CreEYFP Reporter Mouse Allows Fate Mapping of Th17 Cells
2009
Abstract The need for reporter lines able to faithfully track Th17 cells in vivo has become an issue of exceptional importance. To address this, we generated a mouse strain in which Cre recombinase is expressed from the IL-17F promoter. Crossing the IL-17F-Cre allele to a conditional enhanced yellow fluorescent protein (EYFP) reporter mouse yielded the IL-17F-CreEYFP strain, in which IL-17F expression is twinned with EYFP in live IL-17F-expressing cells. Although we demonstrate that IL-17F expression is restricted to CD4+ T cells during experimental autoimmune encephalomyelitis, IL-17F-CreEYFP CD8 T cells robustly expressed IL-17F in response to TGF-β, IL-6, and IL-23. Fate mapping of IL-17…
Single-cell RNA sequencing unveils the shared and the distinct cytotoxic hallmarks of human TCRVδ1 and TCRVδ2 γδ T lymphocytes
2019
γδ T lymphocytes represent ∼1% of human peripheral blood mononuclear cells and even more cells in most tissues of vertebrates. Although they have important anticancer functions, most current single-cell RNA sequencing (scRNA-seq) studies do not identify γδ T lymphocytes because their transcriptomes at the single-cell level are unknown. Here we show that high-resolution clustering of large scRNA-seq datasets and a combination of gene signatures allow the specific detection of human γδ T lymphocytes and identification of their T cell receptor (TCR)Vδ1 and TCRVδ2 subsets in large datasets from complex cell mixtures. In t -distributed stochastic neighbor embedding plots from blood and tumor sa…
In vivo and in vitro sensitivity of blastic plasmacytoid dendritic cell neoplasm to SL-401, an interleukin-3 receptor targeted biologic agent.
2015
International audience; Blastic plasmacytoid dendritic cell neoplasm is an aggressive malignancy derived from plasmacytoid dendritic cells. There is currently no accepted standard of care for treating this neoplasm, and therapeutic strategies have never been prospectively evaluated. Since blastic plasmacytoid dendritic cell neoplasm cells express high levels of interleukin-3 receptor α chain (IL3-Rα or CD123), antitumor effects of the interleukin-3 receptor-targeted drug SL-401 against blastic plasmacytoid dendritic cell neoplasm were evaluated in vitro and in vivo. The cytotoxicity of SL-401 was assessed in patient-derived blastic plasmacytoid dendritic cell neoplasm cell lines (CAL-1 and …
Effects of adjuvants of the cholera toxin family on CD4 + T cell responses in a murine model of intrarectal immunization with rotavirus-like particles
2011
Mucosal immunization is an important goal of vaccine development to protect against pathogens that use mucosa as portals of entry. However, the use of non-replicating antigens requires the addition of adjuvants.Cholera-like enterotoxins, cholera toxin (CT) from Vibrio cholerae and the heat-labile enterotoxin (LT) from toxinogenic strains of E. coli, as well as the mutant LR-192G and their B subunits (CTB and LTB) have been shown to increase immune responses against unrelated co-administered antigens by mucosal routes. However, their mechanism of action is very complex and not completely understood and differences exist between holotoxins and B subunits and within molecules, differences exis…
Etude physiopathologique de la réponse immunitaire au cours de la thrombopénie immunologique (purpura thrombopénique immunologique)
2010
Immune thrombocytopenia (ITP) is an autoimmune disease responsible for a peripheral immune destruction of platelets associated with an inappropriate bone marrow production. In this work, we first review the mechanisms involved in the pathogenesis of ITP. We also focus on the T cell immune response, highlighting the key role of regulatory T cells (Treg) in peripheral tolerance. The implication of the spleen in the immune response and the effects of rituximab, a B cell depleting therapy, are discussed. Then, our results obtained from 40 ITP patients are reported. Despite the fact that CD4+CD25HighFoxp3+ circulating Treg levels are similar between patients and controls, a significant increase …
Synthesis of curcumin derivatives and analysis of their antitumor effects in triple negative breast cancer (TNBC) cell lines
2019
We analyzed antitumor effects of a series of curcumin analogues. Some of them were obtained by reaction of substitution involving the two phenolic OH groups of curcumin while the analogues with a substituent at C-4 was prepared following an original procedure that regards the condensation of benzenesulfenic acid onto the nucleophilic central carbon of the curcumin skeleton. We analyzed cytotoxic effects of such derivatives on two TNBC (triple negative breast cancer) cell lines, SUM 149 and MDA-MB-231, but only three of them showed an IC50 in a lower micromolar range with respect to curcumin. We also focused on these three derivatives that in both cell lines exhibited a higher or at least eq…
Synthesis and Antitumor Activity of New Thiazole Nortopsentin Analogs
2016
New thiazole nortopsentin analogs in which one of the two indole units was replaced by a naphthyl and/or 7-azaindolyl portion, were conveniently synthesized. Among these, three derivatives showed good antiproliferative activity, in particular against MCF7 cell line, with GI50 values in the micromolar range. Their cytotoxic effect on MCF7 cells was further investigated in order to elucidate their mode of action. Results showed that the three compounds act as pro-apoptotic agents inducing a clear shift of viable cells towards early apoptosis, while not exerting necrotic effects. They also caused cell cycle perturbation with significant decrease in the percentage of cells in the G0/G1 and S ph…
Smad7 controls resistance of colitogenic T cells to regulatory T cell-mediated suppression.
2008
Background & Aims Foxp3-expressing regulatory T cells (Tregs) play a key role in the maintenance of the gut immune homeostasis, and an intact transforming growth factor (TGF)-β signaling is required for their function. In inflammatory bowel disease (IBD), the TGF-β signaling is impaired because of high expression of the inhibitory molecule Smad7. Although no intrinsic defects in Tregs function have been shown in IBD, it is still unknown whether colitogenic T cells are susceptible to Treg-mediated suppression. In this study, we have investigated whether IBD mucosal CD4+ T cells are resistant to Tregs and whether Smad7 is involved in this process. Methods IBD lamina propria mononuclear cells …
Cytotoxic eudesmane sesquiterpenes from Crepis sancta
2019
Abstract Chemical exploration of Crepis sancta (L.) Bornm. (Asteraceae) aerial parts afforded two new eudesmane sesquiterpenes (1 and 2) together with three known congeners (3-5) and two known methylated flavonoids (6 and 7). Structure elucidation of the new compounds was unambiguously performed based on HRESIMS, 1D and 2D NMR spectroscopic analyses. All isolated compounds were subjected to an in vitro cytotoxicity assay against mouse lymphoma (L5178Y) cells, revealing moderate activities with IC50 ranging from 7.9 to 21.0 μM.