Search results for "T cell"

Memory CD8+ T Cell Protection From Viral Reinfection Depends on Interleukin-33 Alarmin Signals

2019

Memory CD8+ cytotoxic T lymphocytes (CTLs) can protect against viral reinfection. However, the signals driving rapid memory CTL reactivation have remained ill-defined. Viral infections can trigger the release of the alarmin interleukin-33 (IL-33) from non-hematopoietic cells. IL-33 signals through its unique receptor ST2 to promote primary effector expansion and activation of CTLs. Here, we show that the transcription factor STAT4 regulated the expression of ST2 on CTLs in vitro and in vivo in primary infections with lymphocytic choriomeningitis virus (LCMV). In the primary antiviral response, IL-33 enhanced effector differentiation and antiviral cytokine production in a CTL-intrinsic manne…

Vγ9Vδ2 T cells as a promising innovative tool for immunotherapy of hematologic malignancies

2011

The potent anti-tumor activities of γδ T cells, their ability to produce pro-inflammatory cytokines, and their strong cytolytic activity have prompted the development of protocols in which γδ agonists or ex vivo-expanded γδ cells are administered to tumor patients. γδ T cells can be selectively activated by either synthetic phosphoantigens or by drugs that enhance their accumulation into stressed cells as aminobisphosphonates, thus offering new avenues for the development of γδ T cell-based immunotherapies. The recent development of small drugs selectively activating Vγ9Vδ2 T lymphocytes, which upregulate the endogenous phosphoantigens, has enabled the investigators to design the experiment…

Virulence factor rtx in Legionella pneumophila, evidence suggesting it is a modular multifunctional protein

2008

Abstract Background The repeats in toxin (Rtx) are an important pathogenicity factor involved in host cells invasion of Legionella pneumophila and other pathogenic bacteria. Its role in escaping the host immune system and cytotoxic activity is well known. Its repeated motives and modularity make Rtx a multifunctional factor in pathogenicity. Results The comparative analysis of rtx gene among 6 strains of L. pneumophila showed modularity in their structures. Among compared genomes, the N-terminal region of the protein presents highly dissimilar repeats with functionally similar domains. On the contrary, the C-terminal region is maintained with a fashionable modular configuration, which gives…

Design and simulation of QCA-based 3-bit binary to gray and vice versa code converter in reversible and non-reversible mode

2022

The current Very Large-Scale Integration (VLSI) technology has reached its peak due to the fundamental physical limits of Complementary Metal-Oxide-Semiconductor (CMOS). Quantum-dot Cellular Automata (QCA) is considered a proper alternative to CMOS technology in digital circuit design. QCA has features like low power, small area, and high speed in nanoscale digital circuit design. A code converter is a circuit that converts a determined code to another one. Code converters such as Binary to Gray, Gray to Binary, and Binary to BCD converters have a crucial role in fast signal processing in digital systems. Also, code converters are used as a base unit for data transmission into the Arithmeti…

Differential influence of vemurafenib and dabrafenib on patient lymphocytes despite similar clinical efficacy in melanoma

2014

Background: Since the majority of melanomas eventually become resistant and progress, combining selective BRAF inhibitors (BRAFi) with immunotherapies has been proposed to achieve more durable treatment responses. Here, we explored the impact of selective BRAFi on the hosts’ immune system. Patients and methods: Clinical data, whole blood counts (WBC) and serum lactate dehydrogenase (LDH) of 277 vemurafenib- and 65 dabrafenib-treated melanoma patients were evaluated. The frequency and phenotype of lymphocyte subpopulations were determined by flow cytometry while T cell cytokine secretion was measured by multiplex assays. Results: Progression-free survival (PFS) as well as overall survival (O…

Reparative giant cell granuloma in a pediatric patient

2007

Reparative giant cell granulomas are benign, infrequent tumors, of non-odontogenic origin, that develop at central or peripheral level. Peripherally located lesions are frequently denominated ‘giant cell epulis’, and never correspond to true neoplasia, but rather to inflammatory reactions secondary to another lesion (hemorrhage, etc.). It should be taken into account, that in general, head and neck tumors of infancy usually demonstrate an atypical biological behaviour. Furthermore, the anatomicopathologic diagnosis is often compromised in this type of lesion. We present the case of a 6-year-old boy, who, three weeks after suffering a slight facial trauma, developed a painless, exophytic swe…

Expression and characterization of the recombinant juvenile hormone epoxide hydrolase (JHEH) from Manduca sexta.

1998

The cDNA of the microsomal Juvenile Hormone Epoxide Hydrolase (JHEH) from Manduca sexta was expressed in vitro in the baculovirus system. In insect cell culture, the recombinant enzyme (Ms-JHEH) was produced at a high level (100 fold over background EH catalytic activity). As expected, Ms-JHEH was localized in the microsomal fraction with a molecular mass of approximately 50 kDa. Ms-JHEH showed a substrate and inhibitor spectrum similar to the wild type JHEH isolated from eggs of M. sexta. Its enzymatic activity was the highest for Juvenile Hormone III. Ms-JHEH hydrolyzed several trans-epoxides faster than cis-epoxides. A putative hydroxyl-acyl enzyme intermediate was isolated suggesting a …

Models of Immune Aging

2018

Abstract Biochemical changes, impaired immune responses to new antigens, and inflammation-based disorders are commonly found in aged individuals. Thus, many studies have addressed the immune system of healthy elderly, including centenarians, since a well-preserved immune system appears to be a major factor of longevity. Longitudinal studies in humans are complicated, as most immune changes associated with aging develop slowly. Human models of accelerated immune aging in clinical conditions allow exploring the age-related changes in the human immune system and the mechanisms of accelerated aging in chronic infections and autoimmunity. Even if they do not perfectly mimic immune function and i…

Inhibition of cAMP Degradation Improves Regulatory T Cell-Mediated Suppression of Allergic Airway Disease.

2009

Special Features of the Hippocampal Formation with Respect to Seizure Conditions

1987

The hippocampus has long been known as a region particularly prone to epileptiform discharges (Kandel et al. 1961). Connections and physiology of this archaic cortical structure are relatively well charac-terized and a wealth of information on features favoring exaggerated neuronal activity has emerged in recent years. The lamellar organization of the hippo-campus (Andersen et al. 1971) may be one of these features; it certainly has facilitated their investigation. Tissue slices cut along the lamellae, perpendicular to the axis of the structure, contain a relatively undisturbed chain of neurons which can be rigorously investigated in vitro. The results from such experiments have allowed mod…