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High Affinity Receptor (high + affinity_receptor)
Selected AbstractsNERVE GROWTH FACTOR RESCUE OF CISPLATIN NEUROTOXICITY IS MEDIATED THROUGH THE HIGH AFFINITY RECEPTOR: STUDIES IN PC12 CELLS AND P75 NULL MOUSE DORSAL ROOT GANGLIAJOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 1 2002SJ Fischer Nerve growth factor (NGF) rescues dorsal root ganglion neurons and PC12 cells from cisplatin-induced cell death. Two model systems were used to demonstrate that rescue is mediated through the high affinity NGF receptor. In dorsal root ganglion (DRG) neurons isolated from p75(,/,) and control mice, 20 ng/ml NGF completely prevented cisplatin-induced death. In PC12 cells, we overexpressed receptor chimeras between the tumor necrosis factor and NGF receptors. We demonstrated that activation of the intracellular domain of Trk A is responsible for the NGF rescue effect. [source] Morphine-like substance in leech gangliaFEBS JOURNAL, Issue 8 2000Evidence, immune modulation Binding experiments followed by measurement of nitric oxide release revealed an opiate alkaloid high affinity receptor with no affinity to opioids, representing a new µ-subtype receptor in the brain of the leech Theromyzon tessulatum. In addition, evidence of morphine-like substances was found in immunocytochemical studies and HPLC coupled to electrochemical detection (500 mV and 0.02 Hz). Based on previous evidence of the involvement of morphine as an immune response inhibitor, we demonstrate that in leech ganglia injection of lipopolysaccharide (LPS; a potent immunostimulatory agent derived from bacteria) provoked an increase in the level of ganglionic morphine-like substances after a prolonged latency period of 24 h (from 2.4 ± 1.1 pmol per ganglion to 78 ± 12.3 pmol per ganglion; P < 0.005; LPS injected 1 µg·mL,1); this effect is both concentration- and time-dependent. Finally, we have demonstrated that morphine, after binding to its own receptor, inhibits leech immunocyte activation through adenylate cyclase inhibition and nitric oxide release. This report confirms that morphine is an evolutionarily stable potent immunomodulator. [source] Counter regulation of the high affinity IgE receptor, Fc,RI, on human airway dendritic cells by IL-4 and IL-10ALLERGY, Issue 11 2009A. Faith Background:, Immunoglobulin E is a signalling molecule within the environment of the respiratory tract, the high affinity receptor for which, Fc,RI, is expressed by dendritic cells (DC). Little is known, however, of the expression and function of Fc,RI on DC in the human respiratory tract. Methods:, CD1c+ DC were purified from surgically resected nasal turbinates of 11 atopic and 12 nonatopic patients with chronic rhinosinusitis. Expression of Fc,RI was determined by flow cytometry. Cytokine production by DC was determined by cytometric bead array. Results:, Expression of Fc,RI was significantly elevated on respiratory tract dendritic cells (RTDC) from atopic as compared to nonatopic patients. Activation of RTDC through Fc,RI induced production of the pro-inflammatory cytokines IL-6 and TNF-,, and the anti-inflammatory cytokine IL-10. The production of IL-6 and TNF-, was elevated in atopic compared to nonatopic patients studied. Conversely IL-10 production was elevated in nonatopic patients. Concomitant activation of Fc,RI and stimulation of RTDC with IL-4 inhibited production of IL-10 by RTDC. Neutralization experiments with anti-IL-10 Ab enhanced whereas addition of exogenous IL-10 to RTDC inhibited Fc,RI-mediated inflammatory cytokine production. Conclusion:, The function of Fc,RI on RTDC from patients with rhinosinusitis is susceptible to counter regulation by IL-4 and IL-10. [source] Common variants in FCER1A influence total serum IgE levels from cord blood up to six years of lifeALLERGY, Issue 9 2009C.-M. Chen Background:, In a recent genome wide scan, a functional promoter variant (rs2251746) in the gene encoding the alpha chain of the high affinity receptor for immunoglobulin E (IgE) (FCER1A) was identified as major determinant of serum IgE levels. Objective:, The aim of this study was to investigate the role of rs2251746 on total IgE levels measured at different stages of life from birth (cord blood) up to the age of 6 and to evaluate its interaction with the environmental influences in two German birth cohorts. Method:, Data from two German birth cohorts were analysed (n = 1043 for the LISA cohort and n = 1842 for the GINI cohort). In the studies, total serum IgE was measured from cord blood, and blood samples taken at the age of 2/3 and 6 years. In a subgroup of the LISA study, house dust samples were collected at age of 3 months and the amount of endotoxin was determined. Random effect models were used to analyse the longitudinal health outcomes. Results:, In the two cohorts, the heterozygote and the rare homozygote of rs2251746 was consistently associated with lower total IgE levels from birth up to the age of 6 years with an allele-dose effect (P < 0.02 for blood samples taken at each time point in both cohorts). No interaction between the two FCER1A encoding gene and environmental exposures including endotoxin, worm infestation and day care centre attendance during early childhood were observed. Conclusion:, Common variants in FCER1A strongly influence basal IgE production independently from environmental stimuli. These effects can be observed already in cord blood pointing to altered gene expression in foetus. [source] Distribution of Langerhans cells and mast cells within the human oral mucosa: new application sites of allergens in sublingual immunotherapy?ALLERGY, Issue 6 2008J.-P. Allam Background:, Sublingual immunotherapy (SLIT) represents an alternative to subcutaneous immunotherapy. While antigen-presenting cells such as Langerhans cells (LCs) are thought to contribute to the effectiveness of SLIT, mast cells (MCs) most likely account for adverse reactions such as sublingual edema. As little is known about LCs and MCs within the oral cavity, we investigated their distribution in search for mucosal sites with highest LCs and lowest MCs density. Methods:, Biopsies were taken simultaneously from human vestibulum, bucca, palatum, lingua, sublingua, gingiva, and skin. Immunohistochemistry and flow cytometry were used to detect MCs, LCs and high affinity receptor for IgE (Fc,RI) expression of LCs. Mixed lymphocyte reactions were performed to assess their stimulatory capacity. Results:, Highest density of MCs was detected within the gingiva, while the lowest density of MCs was found within the palatum and lingua. However, sublingual MCs were located within glands, which might explain swelling of sublingual caruncle in some SLIT patients. Highest density of LCs was detected within the vestibular region with lowest density in sublingual region. Highest expression of Fc,RI was detected on LCs within the vestibulum. Furthermore LCs from different regions displayed similar stimulatory capacity towards allogeneic T cells. Conclusions:, In view of our data, different mucosal regions such as the vestibulum might represent alternative SLIT application sites with potent allergen uptake. Our data might serve as a basis for new application strategies for SLIT to enhance efficiency and reduce local adverse reactions. [source] Evidence of dysfunctional ,2 -adrenoceptor signal system in pre-eclampsiaBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 1 2000B. Aune Senior Registrar Objectives To determine how ,2 -adrenoceptor binding and function differ between healthy women and those with pre-eclampsia. Design Case-control study. Setting Faculty of Medicine, University of Tromsø, Norway. Participants Two groups of pregnant women: eight cases with pre-eclampsia, matched with eight healthy controls. Methods Venous blood was drawn from women in both groups after an overnight rest. The two groups were matched for gestational age which was (mean (SD)) 36.4 (3.8) and 36.5 (4.4) weeks for the pre-eclamptic and control groups, respectively. Six weeks after delivery a second blood sample was obtained. The binding and function of ,2 -adrenoceptors were determined in isolated human mononu-clear leukocytes. The levels of adrenaline and noradrenaline were determined in plasma from venous blood. Results An elevated density of functional ,2 -adrenoceptors was observed in normal pregnancy [mean (SD) 390 (90) vs 270 (60) sites/cell postpartum], due to an increased fraction of receptors in high affinity state, with unaltered total receptor density. The number of functional ,2 -adrenoceptors was reduced in pre-eclampsia [mean (SD) 80 (40) vs 240 (30) sites/cell postpartum], due to a reduction in the total receptor number with an unaltered fraction of high affinity receptors. In pregnancy, both unstimulated and isoprenaline-stimulated cAMP levels were reduced in the women with pre-eclampsia (0.5 (0.2) and 1.7 (0.9) pmol/106 cells, respectively) compared with the normal pregnant controls (mean (SD) 1.2 (0.3) and 4.7 (1.8) pmol/106 cells, respectively). Plasma catecholamine levels were not elevated in the women with pre-eclampsia. Conclusions The increased number of functional ,2 -adrenoceptors may contribute to the vasodilatation seen in normal pregnancy, while the reduced overall number of receptors may be one of several factors that account for increased peripheral vascular resistance in pre-eclampsia. [source] | ||||||||||