Search results for "T cell"
showing 10 items of 2228 documents
Comparative cytotoxicity evaluation of eight root canal sealers
2017
Background The aim of the present study is to evaluate and compare the cytotoxic effects of eight root canal sealers (BioRoot RCS, TotalFill BC Sealer, MTA Fillapex, Sealapex, AH Plus, EasySeal, Pulp Canal Sealer, N2) on immortalized human gingival fibroblasts over a period of 24, 48 and 72 hours. Material and Methods Immortalized human gingival fibroblast-1 HGF-1 (ATCC CRL-2014) were incubated. Root canal sealers were then placed into sterile, cylindrical Teflon moulds. The extraction was made eluting the sealers in cell culture medium. Cells (1 × 104) were seeded in each well of a 96-well plate and incubated for 24 h at 37°C. Cultures were then exposed to 100 μL of the extracts medium. Th…
Elevated NKG2D ligand expression in experimental autoimmune encephalomyelitis
2014
T cells remain unclear. Expressing myelin-reactive T cell receptor (TCR) is not sufficient to make a T cell encephalitogenic. In fact, the frequencies of myelin-reactive T cells are comparable between MS patients and healthy individuals, but the ones in MS patients have activated/memory phenotypes. In the animal model of MS, experimental autoimmune encephalomyelitis (EAE), myelin-specific T cells activated with antigen presenting cells (APCs) plus myelin peptide are encephalitogenic, whereas T cells activated with anti-CD3/CD28 antibodies are not. This suggests that APCs provide critical cytokines beyond T cell receptor activation and co-stimulation, contributing to encephalitogenicity. To …
Long-Term Potentiation in the Recurrent Inhibitory Circuit of the Dentate Gyrus
1988
The question of whether long-term potentiation occurs in the inhibitory circuits of the hippocampus remains controversial. Buszaki and Eidelberg (1982), recording extracellularly from putative interneurones (basket cells) in the dentate gyrus and area CAl of the anaesthetized rat, found a prolonged increase in probability of cell firing to afferent stimulation after high-frequency stimulation of Schaffer-commissural fibres, and concluded that LTP occurs at excitatory feedforward synapses onto interneurones. Similarly, Kairis et al (1987) have presented field potential evidence for LTP in feedforward synapses onto inhibitory neurones in the dentate gyrus of the anaesthetized rat. In the hipp…
Influenza A virus infection inhibits the efficient recruitment of Th2 cells into the airways and the development of airway eosinophilia.
2003
Abstract Most infections with respiratory viruses induce Th1 responses characterized by the generation of Th1 and CD8+ T cells secreting IFN-γ, which in turn have been shown to inhibit the development of Th2 cells. Therefore, it could be expected that respiratory viral infections mediate protection against asthma. However, the opposite seems to be true, because viral infections are often associated with the exacerbation of asthma. For this reason, we investigated what effect an influenza A (flu) virus infection has on the development of asthma. We found that flu infection 1, 3, 6, or 9 wk before allergen airway challenge resulted in a strong suppression of allergen-induced airway eosinophil…
Analyses of phenotypic and functional characteristics of CX3CR1-expressing natural killer cells
2011
Summary We previously demonstrated a correlation between the frequency of CX3CR1-expressing human natural killer (NK) cells and disease activity in multiple sclerosis and showed that CX3CR1high NK cells were more cytotoxic than their CX3CR1neg/low counterparts. Here we aimed to determine whether human NK cell fractions defined by CX3CR1 represent distinct subtypes. Phenotypic and functional NK cell analyses revealed that, distinct from CX3CR1high, CX3CR1neg/low NK cells expressed high amounts of type 2 cytokines, proliferated robustly in response to interleukin-2 and promoted a strong up-regulation of the key co-stimulatory molecule CD40 on monocytes. Co-expression analyses of CX3CR1 and CD…
Functional characterization of SARS-CoV-2 infection suggests a complex inflammatory response and metabolic alterations
2020
AbstractCovid-19, caused by the SARS-CoV-2 virus, has reached the category of a worldwide pandemic. Even though intensive efforts, no effective treatments or a vaccine are available. Molecular characterization of the transcriptional response in Covid-19 patients could be helpful to identify therapeutic targets. In this study, RNAseq data from peripheral blood mononuclear cell samples from Covid-19 patients and healthy controls was analyzed from a functional point of view using probabilistic graphical models. Two networks were built: one based on genes differentially expressed between healthy and infected individuals and another one based on the 2,000 most variable genes in terms of expressi…
Advances in the understanding of mast cell function
2008
Mast cells were formerly thought to contribute mainly to, sometimes even, fatal allergic reactions through the release of biologically highly active cytokines, chemokines, lipid mediators, proteases and biogenic amines. This potential harmful response is triggered by crosslinking of cell-bound IgE by the respective allergen. This review updates our current understanding of the emerging roles of mast cells with an emphasis on their relevance in protective host immunity. The activation of mast cells independently of Immunoglobulin E can lead to the initiation of fast inflammatory reactions, which were shown to be life-saving in murine models of bacterial infections. Besides their critical fun…
TLR3-induced activation of mast cells modulates CD8+ T-cell recruitment.
2005
AbstractMast cells play an important role in host defense against various pathogens, but their role in viral infection has not been clarified in detail. dsRNA, synthesized by various types of viruses and mimicked by polyinosinic-polycytidylic acid (poly(I:C)) is recognized by Toll-like receptor 3 (TLR3). In this study, we demonstrate that poly(I:C) injection in vivo potently stimulates peritoneal mast cells to up-regulate a number of different costimulatory molecules. Therefore, we examined the expression and the functional significance of TLR3 activation in mast cells. Mast cells express TLR3 on the cell surface and intracellularly. After stimulation of mast cells with poly(I:C) and Newcas…
Ghost cell odontogenic carcinoma: a rare case report and review of literature
2014
Objectives: Ghost cell odontogenic carcinoma is a rare condition characterized by ameloblastic-like islands of epithelial cells with aberrant keratinitation in the form of Ghost cell with varying amounts of dysplastic dentina. Material and Methods: We report a case of a 70 year-old woman with a rapid onset of painful swelling right maxillary tumor. Magnetic resonance showed a huge tumor dependent on the right half of the right hard palate with invasion of the pterygoid process and focally to the second branch of the trigeminal. Radiological stage was T4N0. The patient underwent a right subtotal maxillectomy with clear margins. Adjuvant radiotherapy was given. The patient was free of residua…
Sesterterpenes and macrolide derivatives from the endophytic fungus Aplosporella javeedii.
2020
Abstract Five sesterterpenes (1–5) including two new compounds (1 and 2), as well as a new (6) and a known macrolide (7) were isolated from the endophytic fungus Aplosporella javeedii. The structures of the new compounds were elucidated by analysis of their 1D and 2D NMR and HRMS data as well as by comparison with the literature. Compound 4 and its acetyl derivatives 4a, 4b, 4c which were prepared by acetylation of 4 exhibited moderate cytotoxicity against the mouse lymphoma cell line L5178Y with IC50 values ranging from 6.2 to 12.8 μM, respectively. Moreover, 4a and 4c exhibited also cytotoxicity against human leukemia (Jurkat J16) and lymphoma (Ramos) cell lines. Compound 7 showed strong …