Search results for "ACTIVATION"
showing 10 items of 2079 documents
Evidence for T cell receptor-HLA class II molecule interaction in the response to superantigenic bacterial toxins
1991
The staphylococcal enterotoxins and related microbial T cell mitogens stimulate T cells by cross-linking variable parts of the T cell receptor (TcR) with MHC class II molecules on accessory or target cells. In this report we describe that a given combination of T cell, accessory cell (AC) and toxin can be non-stimulatory. However, the same T cell can respond to the same toxin on another AC and the same AC can present the same toxin to another T cell. This indicates that in the complex formed between TcR, toxin and class II molecule an interaction between TcR and class II molecule takes place.
γδ T cells and their clinical application in colon cancer
2023
In recent years, research has focused on colorectal cancer to implement modern treatment approaches to improve patient survival. In this new era, γδ T cells constitute a new and promising candidate to treat many types of cancer because of their potent killing activity and their ability to recognize tumor antigens independently of HLA molecules. Here, we focus on the roles that γδ T cells play in antitumor immunity, especially in colorectal cancer. Furthermore, we provide an overview of small-scale clinical trials in patients with colorectal cancer employing either in vivo activation or adoptive transfer of ex vivo expanded γδ T cells and suggest possible combinatorial approaches to treat co…
Colony-stimulating factor-1-induced oscillations in phosphatidylinositol-3 kinase/AKT are required for caspase activation in monocytes undergoing dif…
2009
Abstract The differentiation of human peripheral blood monocytes into resident macrophages is driven by colony-stimulating factor-1 (CSF-1), which upon interaction with CSF-1 receptor (CSF-1R) induces within minutes the phosphorylation of its cytoplasmic tyrosine residues and the activation of multiple signaling complexes. Caspase-8 and -3 are activated at day 2 to 3 and contribute to macrophage differentiation, for example, through cleavage of nucleophosmin. Here, we show that the phosphatidylinositol-3 kinase and the downstream serine/threonine kinase AKT connect CSF-1R activation to caspase-8 cleavage. Most importantly, we demonstrate that successive waves of AKT activation with increasi…
Fine-tuning nucleophosmin in macrophage differentiation and activation
2011
Abstract M-CSF–driven differentiation of peripheral blood monocytes is one of the sources of tissue macrophages. In humans and mice, the differentiation process involves the activation of caspases that cleave a limited number of proteins. One of these proteins is nucleophosmin (NPM1), a multifunctional and ubiquitous protein. Here, we show that caspases activated in monocytes exposed to M-CSF cleave NPM1 at D213 to generate a 30-kDa N-terminal fragment. The protein is further cleaved into a 20-kDa fragment, which involves cathepsin B. NPM1 fragments contribute to the limited motility, migration, and phagocytosis capabilities of resting macrophages. Their activation with lipopolysaccharides …
Tumor necrosis factor (TNF)-alpha but not TNF-beta induces secretion of colony stimulating factor for macrophages (CSF-1) by human monocytes
1987
Abstract Tumor necrosis factor (TNF)-alpha has been identified as a major inducer of colony stimulating factor (CSF)-secretion by human vascular endothelial cells and fibroblasts. In the present study we assessed the capacity of TNFs to induce release of CSF-1 from highly purified peripheral blood monocyte preparations. Whereas monocytes do not accumulate CSF-1 messenger (m)RNA constitutively and consequently do not produce CSF-1 protein, CSF-1 mRNA and protein secretion became detectable, when monocytes were cultured in the presence of TNF-alpha, that was synergistically enhanced by interferon-gamma (IFN-gamma). However, under identical experimental conditions TNF-beta failed to induce mon…
A new biologically active acylated triterpene saponin from Silene fortunei.
1998
A new acylated triterpene-saponin (1), together with a mixture of the known jenisseensosides C and D, has been isolated from the roots of Silene fortunei. The structure of the new compound was established by chemical means and spectroscopic methods as 3-O-[beta-D-galactopyranosyl-(1-->2)-beta-D-glucuronopyranosyl]-28 -O- [[alpha-L-arabinopyranosyl-(1-->2)-alpha-L-arabinopyranosyl- (1-->3)-b eta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)]-[beta-D- glucopyranosyl-(1-->3)]-4-O-acetyl-beta-D-fucopyranosyl]quillaic acid. This saponin showed a significant enhancement of granulocyte phagocytosis in vitro.
Jenisseensosides C and D, biologically active acylated triterpene saponins from Silene jenisseensis
1997
Abstract We previously reported the isolation and structure elucidation of a new trans - p -methoxycinnamoyl triterpene-saponin along with its cis - p -methoxycinnamoyl isomer as an inseparable mixture from the roots of Silene jenisseensis . In a continuing study on this plant, two additional new acylated triterpene-saponins were obtained as an inseparable mixture. Their structures have been established by chemical means and spectroscopic methods including 1D and 2D homonuclear and heteronuclear correlation NMR spectroscopy as 3- O -[β- d -galactopyranosyl-(1 → 2)-β- d -glucuronopyranosyl]-28- O -[{α- l -rhamnopyranosyl-(1 → 2)}- {4- O - trans - p -methoxycinnamoyl}-β- d -fucopyranosyl] qui…
Independent and interactive effects of immune activation and larval diet on adult immune function, growth and development in the greater wax moth (Ga…
2018
Organisms in the wild are likely to face multiple immune challenges as well as additional ecological stressors, yet their interactive effects on immune function are poorly understood. Insects are found to respond to cues of increased infection risk by enhancing their immune capacity. However, such adaptive plasticity in immune function may be limited by physiological and environmental constraints. Here, we investigated the effects of two environmental stressors - poor larval diet and an artificial parasite-like immune challenge at the pupal stage - on adult immune function, growth and development in the greater wax moth (Galleria mellonella). Males whose immune system was activated with an …
The Microbiota Promotes Arterial Thrombosis in Low-Density Lipoprotein Receptor-Deficient Mice
2019
Our results demonstrate a functional role for the commensal microbiota in atherothrombosis. In a ferric chloride injury model of the carotid artery, GF C57BL/6J mice had increased occlusion times compared to colonized controls. Interestingly, in late atherosclerosis, HFD-fed GF Ldlr−/− mice had reduced plaque rupture-induced thrombus growth in the carotid artery and diminished ex vivo thrombus formation under arterial flow conditions.
Cellular immune activation in Sardinian middle-aged, older adults and centenarians
2017
In addition to viral infections, malignant disorders, autoimmune diseases, and allograft rejection episodes, neopterin increases in older people where it is found to be predictive of overall mortality. Thus, the serum concentrations of this biomarker of systemic immune and inflammation activation, were measured in a small cohort of Sardinian middle-aged, older adults and centenarians. There was a significant positive correlation between neopterin concentrations and age with the subjects in the 95-year-old group with the highest values. Notably, the group of centenarians had neopterin values comparable to those of 80- and 90-year-old groups, and significantly lower than that of 95-year-old g…