Search results for " T cell"
showing 10 items of 1161 documents
Analogues of cytotoxic squamocin using reliable reactions: new insights into the reactivity and role of the α,β-unsaturated lactone of the annonaceou…
2006
Abstract A small library of squamocin analogues has been prepared and screened biologically (cytotoxicity, inhibition of mitochondrial complex I and complex III). To centre diversity on a crucial part of the molecule (i.e., the α,β-unsaturated lactone), an original and reliable lactone opening reaction has been discovered and exploited among other efficient reactions.
Novel Stilbene-Based Antileukemic Agents Active in P-Glycoprotein Expressing and Apoptosis-Resistant Acute Leukaemia Cell Lines.
2005
Abstract The stilbene scaffold is a basic element for a number of biologically active natural and synthetic compounds and in accordance with Evans’ definition it can be considered as a privileged structure. One of the most relevant and studied stilbenes is Resveratrol, a phytoalexin present in grapes, endowed with chemopreventive and chemotherapeutic properties and able to induce apoptosis in different cancer cell lines. Since reduced apoptosis has been implicated in the development and progression of malignant tumors and in the occurrence of chemoresistant phenotypes, resveratrol-induced apoptosis might therefore contribute to its antitumor activity. However, resveratrol is a not potent cy…
Tuning antiviral CD8 T-cell response via proline-altered peptide ligand vaccination
2019
AbstractViral escape from CD8+cytotoxic T lymphocyte responses correlates with disease progression and represents a significant challenge for vaccination. Here, we demonstrate that CD8+T cell recognition of the naturally occurring MHC-I-restricted LCMV-associated immune escape variant Y4F is restored following vaccination with a proline-altered peptide ligand (APL). The APL increases MHC/peptide (pMHC) complex stability, rigidifies the peptide and facilitates T cell receptor (TCR) recognition through reduced entropy costs. Structural analyses of pMHC complexes before and after TCR binding, combined with biophysical analyses, revealed that although the TCR binds similarly to all complexes, t…
Retinoid acid and analogs as potent inducers of differentiation and apoptosis. New promising chemopreventive and chemotherapeutic agents in oncology
2001
Abstract In this report we will describe the preparation and the biological activity of a novel class of heterocyclic arotinoids endowed with potent cytotoxic and apoptotic acitivity. Structureactivity relationship studies revealed that the different stereochemistry at the C9 double bond of retinoids seems associated with a different biological activity: potent apoptotic activity for the cis-isomers, whereas differentiating activity for the trans structures. An interesting modified Wittig procedure that allows easily to arotinoids will also be described. The substitution of the alkenyl portion with a more flexible oxymethyl or aminomethyl moiety gave compounds with poor activity, whereas i…
Evaluation of the Cytotoxicity of Cholesterol Oxides in Human Colon Cancer Caco-2 Cells
2014
The content of cholesterol oxides (COPs) in foods varies between 0.1 and 294.3 mg/g. These oxides are formed by auto-oxidative enzymatic processes promoted by the heat treatment of food and/or to exposition of them to the presence of oxygen and sunlight during storage. Their importance is that they are associated with pathological processes like apoptosis, dyslipidemia and pro-oxidative states, among others. The objective was to evaluate the cytotoxicity, by means MTT assay, of 7-keto cholesterol (7KC), cholestane-triol (Triol), α-epoxy cholesterol (α-epoxy C), β-epoxy cholesterol (β-epoxy C) in differentiated Caco-2 cells at 120μM for 24, 48 and 72h.Triol was the most cytotoxic COP, with a…
Binary and tertiary combinations of 3-ADON, 15-ADON and AOH mycotoxins on HepG2 cells: Evaluation of cytotoxic effects and detection of metabolite pr…
2015
2014
Pandemic and seasonal influenza viruses cause considerable morbidity and mortality in the general human population. Protection from severe disease may result from vaccines that activate antigen-presenting DC for effective stimulation of influenza-specific memory T cells. Special attention is paid to vaccine-induced CD8+ T-cell responses, because they are mainly directed against conserved internal influenza proteins thereby presumably mediating cross-protection against circulating seasonal as well as emerging pandemic virus strains. Our study showed that influenza whole virus vaccines of major seasonal A and B strains activated DC more efficiently than those of pandemic swine-origin H1N1 and…
Characterisation of gd T cells infiltrating colorectal cancer
2021
We have read with great interest the paper by de Vries et al 1 reporting on the immune landscape of colorectal cancer (CRC) by high-dimensional mass cytometry, flow cytometry and single cell RNA sequencing. Among clusters of immune cells infiltrating CRC, authors have identified two populations of γδ T cells: one programmed cell death protein 1 (PD-1)+ population is almost exclusively found in DNA mismatch repair (MMR)-deficient (d) tumours, constitutes up to 8.4% of CD45+ cells and has an activated phenotype, and a PD-1− counterpart with a resting phenotype, which is also found in colorectal normal mucosa and MMR-proficient (p) tumours. Using deconvolution of transcriptomic datasets and si…
Evaluation of Bone Marrow CD8+ tissue-Resident Memory T Cells in Multiple Myeloma
2019
Background: CD8+ T cell responses are an essential component of the adaptive immune system. After resolution of infection a small population of memory cells is formed. In relation to circulatory patterns, different subsets of memory CD8+ T cells can be identified: the central memory (CM) and the effector memory T cells (EM) (Martin MD, et al., Front Immunol. 2018). In addition, it has been described a subset of resident memory T cells (TRM) permanently living in peripheral tissues, including the bone marrow (BM) (Di Rosa F., et al., Nat Rev Immunol. 2016). It is conceivable that these cells can contribute to the defence toward haematological tumours infiltrating the BM. Therefore, we perfor…
Cytotoxic effects of individual and combined sterigmatocystin and nivalenol on liver hepatocellular carcinoma cells
2020
Abstract Since humans are exposed to different mycotoxins through daily intake, there is increasing concern about the adverse effects of the interactions between them. Cytotoxicity of sterigmatocystin (STE) and nivalenol (NIV) alone and in combination in human hepatocarcinoma (HepG2) cells was evaluated by MTT assay. Furthermore, ROS production and alteration of ΔΨm as mechanisms of action were assessed. Cells were treated with concentrations ranging from 0.15 to 5 μM for NIV and from 0.78 to 50 μM for STE individually and in binary combinations. The combination ratio between the mixture STE + NIV was 10:1. The IC50 values of NIV ranged from 0.96 to 0.66 μM, whereas no IC50 values were obta…