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Tumour-derived soluble MIC ligands impair expression of NKG2D and T-cell activation 总被引:64,自引:0,他引:64
Engagement of the NKG2D receptor by tumour-associated ligands may promote tumour rejection by stimulating innate and adaptive lymphocyte responses. In humans, NKG2D is expressed on most natural killer cells, gammadelta T cells and CD8alphabeta T cells. Ligands of NKG2D include the major histocompatibility complex class I homologues MICA and MICB, which function as signals of cellular stress. These molecules are absent from most cells and tissues but can be induced by viral and bacterial infections and are frequently expressed in epithelial tumours. MIC engagement of NKG2D triggers natural killer cells and costimulates antigen-specific effector T cells. Here we show that binding of MIC induces endocytosis and degradation of NKG2D. Expression of NKG2D is reduced markedly on large numbers of tumour-infiltrating and matched peripheral blood T cells from individuals with cancer. This systemic deficiency is associated with circulating tumour-derived soluble MICA, causing the downregulation of NKG2D and in turn severe impairment of the responsiveness of tumour-antigen-specific effector T cells. This mode of T-cell silencing may promote tumour immune evasion and, by inference, compromise host resistance to infections. 相似文献
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Veronika Kemény K. Farkas A. Körösi T. Szarvas 《Cellular and molecular life sciences : CMLS》1968,24(6):611-613
Zusammenfassung Bösartige Lungengeschwulstgewebe verschiedener Zelltypen wurden mit Hydrocortison 13H, 23H inkubiert. Die freien, markierten Steroide wurden extrahiert, chromatographisch getrennt und identifiziert.
The steroids obtained fromN. V. Organon, OSS are gratefully acknowledged. The authors also acknowledge with gratitude the technical assistance of MissMaria Borbás. 相似文献
The steroids obtained fromN. V. Organon, OSS are gratefully acknowledged. The authors also acknowledge with gratitude the technical assistance of MissMaria Borbás. 相似文献
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P. Vecsei K. Farkas Veronika Kemény Maria Harangozó 《Cellular and molecular life sciences : CMLS》1964,20(8):458-459
Zusammenfassung Der Einbau von H3-Progesteron-Radioaktivität in verschiedenen Corticosteroiden wurde bei mit Formalin und Hydrocortison behandelten, trächtigen und neugeborenen Ratten mit Hilfe vonin vitro überlebenden Nebennierenschnittenpost partum untersucht. Die 18-OH-Corticosteronaktivität steigt nach Formalinbehandlung an; die Aktivitätpost partum gebildeter Corticosteroide vermindert sich im allgemeinen; bei neugeborenen Ratten ist die Aktivität des Corticosterons vermindert. 相似文献
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Zusammenfassung Die Aldosteronproduktion der kompensatorisch-hypertrophisierten Nebennieren wurde im Rattenexperiment untersucht. Die Corticosteronproduktion zeigte eine wesentliche Zunahme, dagegen blieben die Aldosteronwerte unverändert, was gegen eine ACTH-Regelung der Aldosteronsekretion spricht. 相似文献
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Nunutza Soto-Feine Veronika Petersen A. N. Tchernitchin 《Cellular and molecular life sciences : CMLS》1981,37(12):1351-1352
Summary Prostaglandin biosynthesis inhibition by indomethacin blocks estrogen-induced uterine hyperemia, but does not block estrogen-induced uterine eosinophilia and edema.Acknowledgments. Supported by grant B 012815 from the Servicio de Desarrollo Cientifico, Artistico y de Cooperacion Internacional from the University of Chile. 相似文献
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Veronika Tillander Elisabet Arvidsson Nordström Jenny Reilly Malgorzata Strozyk Paul P. Van Veldhoven Mary C. Hunt Stefan E. H. Alexson 《Cellular and molecular life sciences : CMLS》2014,71(5):933-948
Acyl-CoA thioesterase (ACOT) activities are found in prokaryotes and in several compartments of eukaryotes where they hydrolyze a wide range of acyl-CoA substrates and thereby regulate intracellular acyl-CoA/CoA/fatty acid levels. ACOT9 is a mitochondrial ACOT with homologous genes found from bacteria to humans and in this study we have carried out an in-depth kinetic characterization of ACOT9 to determine its possible physiological function. ACOT9 showed unusual kinetic properties with activity peaks for short-, medium-, and saturated long-chain acyl-CoAs with highest V max with propionyl-CoA and (iso) butyryl-CoA while K cat/K m was highest with saturated long-chain acyl-CoAs. Further characterization of the short-chain acyl-CoA activity revealed that ACOT9 also hydrolyzes a number of short-chain acyl-CoAs and short-chain methyl-branched CoA esters that suggest a role for ACOT9 in regulation also of amino acid metabolism. In spite of markedly different K ms, ACOT9 can hydrolyze both short- and long-chain acyl-CoAs simultaneously, indicating that ACOT9 may provide a novel regulatory link between fatty acid and amino acid metabolism in mitochondria. Based on similar acyl-CoA chain-length specificities of recombinant ACOT9 and ACOT activity in mouse brown adipose tissue and kidney mitochondria, we conclude that ACOT9 is the major mitochondrial ACOT hydrolyzing saturated C2-C20-CoA in these tissues. Finally, ACOT9 activity is strongly regulated by NADH and CoA, suggesting that mitochondrial metabolic state regulates the function of ACOT9. 相似文献
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Mühlebach MD Mateo M Sinn PL Prüfer S Uhlig KM Leonard VH Navaratnarajah CK Frenzke M Wong XX Sawatsky B Ramachandran S McCray PB Cichutek K von Messling V Lopez M Cattaneo R 《Nature》2011,480(7378):530-533
Measles virus is an aerosol-transmitted virus that affects more than 10 million children each year and accounts for approximately 120,000 deaths. Although it was long believed to replicate in the respiratory epithelium before disseminating, it was recently shown to infect initially macrophages and dendritic cells of the airways using signalling lymphocytic activation molecule family member 1 (SLAMF1; also called CD150) as a receptor. These cells then cross the respiratory epithelium and transport the infection to lymphatic organs where measles virus replicates vigorously. How and where the virus crosses back into the airways has remained unknown. On the basis of functional analyses of surface proteins preferentially expressed on virus-permissive human epithelial cell lines, here we identify nectin-4 (ref. 8; also called poliovirus-receptor-like-4 (PVRL4)) as a candidate host exit receptor. This adherens junction protein of the immunoglobulin superfamily interacts with the viral attachment protein with high affinity through its membrane-distal domain. Nectin-4 sustains measles virus entry and non-cytopathic lateral spread in well-differentiated primary human airway epithelial sheets infected basolaterally. It is downregulated in infected epithelial cells, including those of macaque tracheae. Although other viruses use receptors to enter hosts or transit through their epithelial barriers, we suggest that measles virus targets nectin-4 to emerge in the airways. Nectin-4 is a cellular marker of several types of cancer, which has implications for ongoing measles-virus-based clinical trials of oncolysis. 相似文献
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The Role of Formalisation, Participation and Context in the Success of Public Involvement Mechanisms in Resource Management 总被引:1,自引:0,他引:1
Jens Newig Veronika Gaube Karin Berkhoff Kai Kaldrack Britta Kastens Juliana Lutz Bianca Schlußmeier Heidelinde Adensam Helmut Haberl 《Systemic Practice and Action Research》2008,21(6):423-441
In the face of complex and uncertain issues, one important goal of public participation in resource management and research is to foster communication and the inclusion of non-expert knowledge—thus the effective flow of information between project organisers and stakeholders. We compare different methods (instruments, tools) that were employed in the German–Austrian ‘PartizipA’ project to structure information flows in participatory processes. Depending on their goals and context, more or less ‘formalised’ and ‘participatory’ methods were applied, the most important being guided interviews, focus groups, agent-based modelling, nutrient modelling, cognitive mapping and group model building as well as the development of a common document. Two regional case studies, both concerned with European-induced institutional change, are portrayed in which the specific participatory methods were embedded. The Austrian case study involved the analysis and modelling of agricultural land use in the region of St. Pölten against the background of the reform of the Common Agricultural Policy, while the implementation of recent European water policy was the issue in the German agricultural region north of Osnabrück. Presenting both cases in their regional context, the applied methods are first described according to the logic of the entire respective process. Subsequently, the specific methods are systematically analysed and compared according to their objective, context and degrees of participation and formalisation. Finally, we evaluate all methods regarding their effectiveness in terms of goal attainment and their potential generalisation, seeking to respond to the question of when a particular method might best be used. 相似文献
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Kaiser BK Yim D Chow IT Gonzalez S Dai Z Mann HH Strong RK Groh V Spies T 《Nature》2007,447(7143):482-486
Tumour-associated ligands of the activating NKG2D (natural killer group 2, member D; also called KLRK1) receptor-which are induced by genotoxic or cellular stress-trigger activation of natural killer cells and co-stimulation of effector T cells, and may thus promote resistance to cancer. However, many progressing tumours in humans counter this anti-tumour activity by shedding the soluble major histocompatibility complex class-I-related ligand MICA, which induces internalization and degradation of NKG2D and stimulates population expansions of normally rare NKG2D+CD4+ T cells with negative regulatory functions. Here we show that on the surface of tumour cells, MICA associates with endoplasmic reticulum protein 5 (ERp5; also called PDIA6 or P5), which, similar to protein disulphide isomerase, usually assists in the folding of nascent proteins inside cells. Pharmacological inhibition of thioreductase activity and ERp5 gene silencing revealed that cell-surface ERp5 function is required for MICA shedding. ERp5 and membrane-anchored MICA form transitory mixed disulphide complexes from which soluble MICA is released after proteolytic cleavage near the cell membrane. Reduction of the seemingly inaccessible disulphide bond in the membrane-proximal alpha3 domain of MICA must involve a large conformational change that enables proteolytic cleavage. These results uncover a molecular mechanism whereby domain-specific deconstruction regulates MICA protein shedding, thereby promoting tumour immune evasion, and identify surface ERp5 as a strategic target for therapeutic intervention. 相似文献
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