Search results for "T Cells"
showing 10 items of 498 documents
Cerebrospinal fluid T-regulatory cells recognize Borrelia burgdorferi NAPA in chronic Lyme borreliosis.
2013
The NapA protein of B. burgdorferi is essential for the persistence of spirochetes in ticks. One of the most intriguing aspects of NapA is its potential to interfere with the host immune system. Here, we investigated the role of the acquired immune responses induced by NapA in the cerebrospinal fluids (CSF) of patients with chronic Lyme borreliosis. We evaluated the cytokine profile induced in microglia cells and CSF T cells following NapA stimulation. We report here that NapA induced a regulatory T (Treg) response in the CSF of patients with chronic Lyme borreliosis and it is able to expand this suppressive response by promoting the production of TGF-β and IL-10 by microglia cells. Collect…
Investigation into mechanisms mediating the inhibitory effect of 1,4-benzodiazepines on mast cells by gene expression profiling.
2013
Abstract Aims This study aims to identify by a molecular genetic approach potential targets in mast cells at which 1,4-benzodiazepines may cause their inhibitory effect on mast cell activity. Main methods Gene expression analyses with microarray gene chip and/or quantitative PCR were performed using 1,4-benzodiazepine-treated human mast cell leukemia HMC-1.2 cells, promyelocytic leukemia HL-60 cells and human mast cells from healthy volunteers and patients with mast cell activation disease (MCAD). Pathway analysis was applied to search for enriched biological functions and canonical pathways within differentially regulated genes. Key findings Both neoplastic and normal human mast cells expr…
Post-infantile giant cell hepatitis in patients with primary sclerosing cholangitis and autoimmune hepatitis.
2008
In post-infancy, multinucleated giant cell hepatitis is rare. Various conditions and diseases associated with post-infantile giant cell hepatitis have been described, but the pathogenesis remains unknown. In this paper we review the case reports of four patients (3 male, 1 female; aged 22 to 32 years) with primary sclerosing cholangitis and autoimmune hepatitis. The follow-up ranges from five to seven years. All patients showed cholestasis and repeated elevation of hepatic transaminases. Patients with viral infections, metabolic disorders and toxic influences were excluded. Histopathology of liver tissue in all four patients revealed giant cell formation with up to 20 nuclei in 20-70% of al…
Peri-implant peripheral giant cell lesions : report of 13 new cases and comparative histological and immunohistochemical analysis with peripheral and…
2019
Background Few cases or peri-implant peripheral giant cell lesions (PGCL) have been reported in the literature. The aim of this study was to report 13 new cases of peri-implant PGCL and compare the expression of smooth muscle actin, Bcl-2 protein, GLUT-1, CD68, osteoprotegerin, receptor activator of nuclear factor kappa-B, Ki-67 and CD34 in these cases with PGCL and central giant cell lesions (CGCL). Material and Methods Clinical data were retrieved from the laboratory records and histological analysis was performed using HE-stained slides. Immunohistochemical reactions for the above mentioned antibodies were performed and digitally scored. Results Peri-implant PGCL mostly affected the post…
Blood group related antigens in ocular cicatricial pemphigoid
2004
Aim: To study the MUC5AC and the blood group related antigen expression in ocular cicatricial pemphigoid (OCP) according to the distribution of Lewis and secretor phenotypes in OCP patients compared to normal subjects. Methods: Immunostaining was performed on conjunctival biopsy specimens from 22 consecutive patients suffering from OCP, using monoclonal antibodies (Mabs) directed against the peptidic core MUC5AC mucin (anti-M1/MUC5AC Mabs) and against the saccharide moieties (anti-blood group related antigens). These latter included anti-Lea, anti-Leb, anti-sialyl Lea, and H type 2 Mabs, which immunoreact with Lewis positive and non-secretor (Lea), Lewis positive and secretor (Leb), Lewis p…
Immunoregulatory role of Jα281 T cells in aged mice developing lupus-like nephritis
2007
Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the emergence of autoreactive T cells. Humans and mice with SLE have reduced numbers of CD1d-restricted invariant natural killer T (iNKT) cells, suggesting a key role for these cells in its immunopathogenesis. This subset uses an invariant TCR constituted by Valpha14 Jalpha281 chains paired with some Vbeta domains. The regulatory role for iNKT cells in non-autoimmune mice was suggested by our previous results showing that aged Jalpha281 knockout (KO) mice produce anti-dsDNA. Here we show that old Jalpha281 KO mice have proteinuria and antibodies against dsDNA and cardiolipin. Histological analysis of Jalpha281 KO m…
5-HT3 receptor-channels coupled with Na+ influx in human T cells: role in T cell activation.
1999
The study was conducted on a human (Jurkat) T cell line, loaded with a Na+ fluorescent probe, SBFI/AM. Serotonin and an agonist of 5-HT3 receptor-channels, 2-methyl-5HT, evoked Na+ influx, whereas the agonists of other serotonergic receptor subtypes, i.e., 5-HT1A and 5-HT1B receptors, failed to induce Na+ influx in these cells. By using 3H-BRL43694, an agonist of 5-HT3 receptor-channels, we characterized 5-HT3 lymphocyte receptors which exhibited a density (Bmax) of 300 +/- 20 fmol/10(6) cells and a Kd of 30 nM in Jurkat T cells. The T-cell 5-HT3 receptor-channel is not regulated either by the protein kinase C or by the free intracellular calcium concentrations as the agents known to activa…
Ionotrophic 5-hydroxytryptamine type 3 receptor activates the protein kinase C-dependent phospholipase D pathway in human T-cells
1999
The present study was undertaken to investigate the role of the 5-hydroxytryptamine (5-HT) ionotrophic receptor 5-HT3 in the activation of human Jurkat T-cells. 5-HT and 2-methyl-5-HT (2Me-5-HT), an agonist of the 5-HT3 receptor, induced increases in intracellular free Na+ concentrations, [Na+]i, via opening of the ionotrophic receptor in these cells. These two serotonergic (5-hydroxytryptaminergic) agents potentiated phytohaemagglutinin (PHA)-induced T-cell activation. However, they failed to potentiate dioctanoglycerol-plus-ionomycin-stimulated T-cell blastogenesis. Interestingly, an inhibitor of protein kinase C (PKC), GF 109203X, curtailed significantly 5-HT and 2Me-5-HT-potentiated T-c…
Regulation of IgE production and airway reactivity by CD4(-)CD8(-) regulatory T cells
2015
The mechanisms of tolerance induction occurring in the course of allergen-specific immunotherapy have not been elucidated in full detail. Our study aimed to characterize high zone tolerance in mouse models of type I allergy and of allergic airway inflammation induced by subcutaneous sensitization of mice with high doses of the model allergen ovalbumin (OVA) without the use of adjuvant. Mice were immunized by subcutaneous injection of high doses (HD) of OVA or, for comparison, low doses (LD) of OVA in saline. HD-mice showed lower specific IgE, but augmented IgG in sera than LD-mice. Pre-treatment of mice with HD-OVA antigen-specifically inhibited IgE production subsequently induced by LD-OVA…
Mast Cells Induce Migration of Dendritic Cells in a Murine Model of Acute Allergic Airway Disease
2009
<i>Background: </i>The migration of dendritic cells (DCs) from the lungs to the regional lymph nodes is necessary for the development of allergic airway disease. Following activation, mast cells release a variety of stored or de novo-produced inflammatory mediators, several of them being capable of activating DCs. In this study, the role of mast cells on DC migration from the lungs to the thoracic lymph nodes was investigated in sensitized mice. <i>Methods:</i> Mast cell-deficient mice (Kit<sup>W-sh/W-sh</sup>) and their wild-type counterparts were sensitized intraperitoneally with ovalbumine (OVA) in saline and challenged by a single intranasal administr…