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81.
In vivo impact of CpG1826 oligodeoxynucleotide on CD8 T cell primary responses and survival 总被引:3,自引:0,他引:3
Beloeil L Tomkowiak M Angelov G Walzer T Dubois P Marvel J 《Journal of immunology (Baltimore, Md. : 1950)》2003,171(6):2995-3002
CpG oligodeoxynucleotide (ODN) promotes maturation of APCs in vivo and induces strong type 1 T cell responses in mice. In this study, we have investigated the ability of CpG1826 to modulate peptide-specific CD8 T cell responses in a context where CD4 T cells are likely to play a minor role. The effects of CpG1826 were evaluated in a system where a population of NP68-specific F5 TCR transgenic CD8 T cells is diluted into a polyclonal host following adoptive transfer into C57BL/10 syngeneic recipients. Using this approach, we found that CpG1826 enhanced the ability of F5 CD8 T cells to undergo multiple divisions in vivo, to express IFN-gamma ex vivo, and to up-regulate memory-associated cell surface markers such as CD122 (IL-2Rbeta) and Ly-6C. Moreover, CpG1826 greatly increased in vivo cytotoxic activity. Using tetramer detection, we found that CpG1826 promoted long-term survival of Ag-specific CD8 T cells after immunization while no NP68-specific cells were detected when the cognate peptide was injected alone. These results indicate that CpG1826 acts as an adjuvant which increases CD8 T cell effector responses and promotes long-term survival of NP68 peptide-specific cells in vivo. They also suggest that this adjuvant can modulate CD8 T cell responses in a system which is likely to be independent of CD4 T cell help. 相似文献
82.
El Alami M Dubois E Oudjama Y Tricot C Wouters J Stalon V Messenguy F 《The Journal of biological chemistry》2003,278(24):21550-21558
In the presence of ornithine and arginine, ornithine carbamoyltransferase (OTCase) and arginase form a one-to-one enzyme complex in which the activity of OTCase is inhibited whereas arginase remains catalytically active. The mechanism by which these nonallosteric enzymes form a stable complex triggered by the binding of their respective substrates raises the question of how such a cooperative association is induced. Analyses of mutations in both enzymes identify residues that are required for their association, some of them being important for catalysis. In arginase, two cysteines at the C terminus of the protein are crucial for its epiarginase function but not for its catalytic activity and trimeric structure. In OTCase, mutations of putative ornithine binding residues, Asp-182, Asn-184, Asn-185, Cys-289, and Glu-256 greatly reduced the affinity for ornithine and impaired the interaction with arginase. The four lysine residues located in the SMG loop, Lys-260, Lys-263, Lys-265, and Lys-268, also play an important role in mediating the sensitivity of OTCase to ornithine and to arginase and appear to be involved in transducing and enhancing the signal given by ornithine for the closure of the catalytic domain. 相似文献
83.
Custaud MA Arnaud SB Monk TH Claustrat B Gharib C Gauquelin-Koch G 《Life sciences》2003,72(9):1001-1014
We investigated in six men the impact of 17 days of head-down bed rest (HDBR) on the daily rhythms of the hormones involved in hydroelectrolytic regulation. This HDBR study was designed to mimic a real space flight. Urine samples were collected at each voiding before, during and after HDBR. Urinary excretion of Growth Hormone (GH), Cortisol, 6 Sulfatoxymelatonin, Normetadrenaline (NMN) and Metadrenaline (NM) was determined. A decrease in urinary cortisol excretion during the night of HDBR was noted. For GH, a rhythm was found before and during HDBR. The rhythm of melatonin, evaluated with the urine excretion of 6 Sulfatoxymelatonin (aMT6S), the main hepatic metabolite, persisted throughout the experiment without any modification to the level of phase. A decrease during the night was noted for normetadrenaline urinary derivates, but only during the HDBR. 相似文献
84.
Ameye L De Becker G Killian C Wilt F Kemps R Kuypers S Dubois P 《Journal of structural biology》2001,134(1):56-66
Properties of the echinoderm skeleton are under biological control, which is exerted in part by the organic matrix embedded in the mineralized part of the skeleton. This organic matrix consists of proteins and glycoproteins whose carbohydrate component is specifically involved in the control mechanisms. The saccharide moiety of the organic matrix of the spines of the echinoid Paracentrotus lividus was characterized using enzyme-linked lectin assays (ELLAs). O-glycoproteins, different types of complex N-glycoproteins, and terminal sialic acids were detected. Sialic acids are known to interact with Ca ions and could play an important role in the mineralization process. Some of the carbohydrate components detected by ELLAs as well as two organic matrix proteins (SM30 and SM50) were localized within different subregions of the spine skeleton using field-emission scanning electron microscopy. The mappings show that some of these components are not homogeneously distributed in the different skeletal subregions. For example, some N-glycoproteins were preferentially located in the putative amorphous subregion of the skeleton, whereas some O-glycoproteins were localized in the subregion where skeletal growth is inhibited. These results suggest that the biological control exerted on the skeletal properties can be partly modulated by local differences in the organic matrix composition. 相似文献
85.
Dubois EA Slob S Zandbergen MA Peute J Goos HJ 《Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology》2001,129(2-3):381-387
The effect of testosterone (T), 11-ketotestosterone (KT) and estradiol (E(2)) on the development of the catfish gonadotropin-releasing hormone system (cfGnRH) of male African catfish (Clarias gariepinus), at the onset of puberty [between 10 and 12 weeks post hatching (ph)] was investigated. The cfGnRH neurons, located in the ventral forebrain, were visualized by immunofluorescence and their numbers were determined and the amounts of cfGnRH-associated peptide (cfGAP) in the pituitary were measured by RIA. Steroid treatments did not significantly alter the numbers of immunoreactive GnRH neurons. However, T and E(2) caused an increase in the amount of GnRH, demonstrated by the intensity of the immunostaining of GnRH neurons and fibers in the brain and the amount of cfGAP in the pituitary. Treatment with KT, the main circulating androgen in adult male catfish, neither changed the number of cfGnRH neurons, nor elevated the cfGnRH content in the pituitary. In previous experiments with younger, prepubertal fish (2-6 weeks ph), T caused an elevation of the number of cfGnRH neurons to the same level as present in pubertal fish of 12-14 weeks. We conclude that the onset of puberty in the male African catfish coincides with the completion of the steroid-dependent structural maturation of the cfGnRH system in the brain. T and/or E(2), however, are still able to exert a positive influence on the amounts of cfGnRH during the later stages of pubertal development, thus still playing a role in the control of the cfGnRH system. 相似文献
86.
Catterou M Dubois F Schaller H Aubanelle L Vilcot B Sangwan-Norreel BS Sangwan RS 《Planta》2001,212(5-6):659-672
Although cell elongation is a basic function of plant morphogenesis, many of the molecular events involved in this process
are still unknown. In this work an extremely dwarf mutant, originally named bul, was used to study one of the main processes of plant development, cell elongation. Genetic analyses revealed that the BUL locus was linked to the nga172 marker on chromosome 3. Recently, after mapping the new dwf7 mutation of Arabidopsis, which is allelic to ste1, it was reported that dwf7 is also linked to the same marker. Sterol analyses of the bul1-1 mutant indicated that bul1-1 is defective in the Δ7-sterol-C5-desaturation step leading to brassinosteroid biosynthesis. Considering these findings, we designated our bul mutant as bul1-1/dwf7-3/ste1-4. The bul1-1 mutant was characterized by a very dwarf phenotype, with delayed development and reduced fertility. The mutant leaves had
a dark-green colour, which was probably due to continuous stomatal closure. The bul1-1 mutant showed a partially de-etiolated phenotype in the dark. Cellular characterization and rescue experiments with brassinosteroids
demonstrated the involvement of the BUL1-1 protein in brassinosteroid-dependent plant growth processes.
Received: 28 April 2000 / Accepted: 6 October 2000 相似文献
87.
Batrancourt B Levy R Lehericy S Hasboun D Samson Y Lavallée I Lamure M Dubois B 《Comptes rendus biologies》2002,325(4):439-455
This study proposes a closer look at the neuropsychological method defined as the study of the neural bases of the behavioural and cognitive functions using an organisation-representation model for current data and knowledge of the brain, and the application of an anatomofunctional database. A Centre of Cognitive Anatomy (CAC) was set up for the collection and processing of neuronatomical, neuropsychological, and psycho-behavioural data for patients presenting sequels of focal brain damage. Such a system would allow concurrent treatment of anatomical and functional data. We would expect the results from such a model to produce stable 'anatomofunctional laws' that would be independent of all inter-individual variations in the functioning of the brain and could be checked against the entire database of information. A direct application would be the improvement of cognitive and/or behavioural rehabilitation of patients with brain damage. 相似文献
88.
Two radiopharmaceuticals, Tc-99m-MIBI (MIBI) and Tc-99m-Tetrofosmin (Tfos), are currently used for in vivo non-invasive monitoring of the MultiDrug Resistant (MDR) status of tumours. As gliomas are highly multidrug resistant, it is expected that the tracers would be poorly retained in those cells, but the in vivo and in vitro studies to date have shown that Tfos was highly retained in malignant gliomas. The high degree of malignancy of tumour cells is linked to alterations of physiological parameters as plasma membrane potential and intracellular pH. In order to elucidate the contribution of those parameters to Tfos and MIBI uptakes in malignant gliomas, we used several glioma cell lines--G111, G5, G152, and 42 MG-BA. These cells showed to be chemoresistant with a high level of expression and activity of the Multidrug Resistant associated Protein 1 (MRP1). They also had an alkaline intracellular pH (pHi) related to the Na+/H+ antiporter (NHE-1) expression and depolarised plasma membranes (-45 to -55 mV). In spite of their chemoresistance, we have found a high accumulation of both radiotracers in gliomas, more important for Tfos than MIBI, related to the presence and activity of NHE-1. In conjunction, the uptakes of the tracers were only partially dependent upon the plasma membrane potential of the glioma cell lines, again Tfos uptake being less dependent on this parameter than MIBI uptake. In conclusion, the evidence accumulated in this study suggests that Tfos could be a suitable glioma marker in vivo. 相似文献
89.
Western Blot and immunohistochemical studies were conducted in the sea pansy Renilla koellikeri, a representative of the earliest multicellular animals with a nervous system, using various antibodies raised against enzymes of the catecholamine biosynthetic pathway. Western blots of sea pansy extracts revealed a protein band that co-migrated with dopamine-beta-hydroxylase (DBH) from mouse adrenal glands. Similar experiments with antisera against tyrosine hydroxylase (TH) revealed several immunoreactive protein bands, all of larger molecular weight than mammalian tyrosine hydroxylase. DBH-like and, to a lesser extent, TH-like and phenylethanolamine N-methyltransferase-like immunoreactivities were detected in ectodermal sensory neurons and associated subectodermal neurites, in neurons of the mesogleal nerve-net and associated amoebocytes, and in some endodermal neurons. While it is still not clear whether the detected TH-immunoreactive proteins represent some form of TH, the presence in sea pansies of a DBH-like protein is in agreement with previously detected norepinephrine-like immunoreactivity in the same species. The widespread distribution of these immunoreactivities in various sea pansy neurons suggests important roles for catecholamines in nerve net activity. 相似文献
90.
European water frogs are characterized by anthropic introductions and Rana ridibunda may be considered as an invasive species. As such translocations may result in introgression of exotic genes in native populations, i.e. genetic pollution, we studied genetic characteristics (on 11 allozymic loci) of natural versus introduced water frogs. Our study contributed to (1) disclose 3 genetic markers allowing the identification of exotic frogs; (2) quantify the proportion of exotic frogs found in natural populations; and (3) suggest how genetic pollution may arise in these frogs. 相似文献