排序方式: 共有56条查询结果,搜索用时 46 毫秒
31.
32.
Natalia Ramírez Lorea Beloki Miriam Ciaúrriz Mercedes Rodríguez-Calvillo David Escors Cristina Mansilla Eva Bandrés Eduardo Olavarría 《Cellular and molecular life sciences : CMLS》2014,71(7):1211-1224
Chemotherapy and/or radiotherapy regular regimens used for conditioning of recipients of hematopoietic stem cell transplantation (SCT) induce a period of transient profound immunosuppression. The onset of a competent immunological response, such as the appearance of viral-specific T cells, is associated with a lower incidence of viral infections after haematopoietic transplantation. The rapid development of immunodominant peptide virus screening together with advances in the design of genetic and non-genetic viral- and tumoural-specific cellular selection strategies have opened new strategies for cellular immunotherapy in oncologic recipients who are highly sensitive to viral infections. However, the rapid development of cellular immunotherapy in SCT has disclosed the role of the T cell selection method in the modulation of functional cell activity and of in vivo secondary effects triggered following immunotherapy. 相似文献
33.
Müller T Hess MW Schiefermeier N Pfaller K Ebner HL Heinz-Erian P Ponstingl H Partsch J Röllinghoff B Köhler H Berger T Lenhartz H Schlenck B Houwen RJ Taylor CJ Zoller H Lechner S Goulet O Utermann G Ruemmele FM Huber LA Janecke AR 《Nature genetics》2008,40(10):1163-1165
Following homozygosity mapping in a single kindred, we identified nonsense and missense mutations in MYO5B, encoding type Vb myosin motor protein, in individuals with microvillus inclusion disease (MVID). MVID is characterized by lack of microvilli on the surface of enterocytes and occurrence of intracellular vacuolar structures containing microvilli. In addition, mislocalization of transferrin receptor in MVID enterocytes suggests that MYO5B deficiency causes defective trafficking of apical and basolateral proteins in MVID. 相似文献
34.
Enterotypes of the human gut microbiome 总被引:6,自引:0,他引:6
Arumugam M Raes J Pelletier E Le Paslier D Yamada T Mende DR Fernandes GR Tap J Bruls T Batto JM Bertalan M Borruel N Casellas F Fernandez L Gautier L Hansen T Hattori M Hayashi T Kleerebezem M Kurokawa K Leclerc M Levenez F Manichanh C Nielsen HB Nielsen T Pons N Poulain J Qin J Sicheritz-Ponten T Tims S Torrents D Ugarte E Zoetendal EG Wang J Guarner F Pedersen O de Vos WM Brunak S Doré J;MetaHIT Consortium Antolín M Artiguenave F Blottiere HM Almeida M Brechot C Cara C Chervaux C Cultrone A 《Nature》2011,473(7346):174-180
Our knowledge of species and functional composition of the human gut microbiome is rapidly increasing, but it is still based on very few cohorts and little is known about variation across the world. By combining 22 newly sequenced faecal metagenomes of individuals from four countries with previously published data sets, here we identify three robust clusters (referred to as enterotypes hereafter) that are not nation or continent specific. We also confirmed the enterotypes in two published, larger cohorts, indicating that intestinal microbiota variation is generally stratified, not continuous. This indicates further the existence of a limited number of well-balanced host-microbial symbiotic states that might respond differently to diet and drug intake. The enterotypes are mostly driven by species composition, but abundant molecular functions are not necessarily provided by abundant species, highlighting the importance of a functional analysis to understand microbial communities. Although individual host properties such as body mass index, age, or gender cannot explain the observed enterotypes, data-driven marker genes or functional modules can be identified for each of these host properties. For example, twelve genes significantly correlate with age and three functional modules with the body mass index, hinting at a diagnostic potential of microbial markers. 相似文献
35.
36.
37.
During protein synthesis, the ribosome accurately selects transfer RNAs (tRNAs) in accordance with the messenger RNA (mRNA) triplet in the decoding centre. tRNA selection is initiated by elongation factor Tu, which delivers tRNA to the aminoacyl tRNA-binding site (A site) and hydrolyses GTP upon establishing codon-anticodon interactions in the decoding centre. At the following proofreading step the ribosome re-examines the tRNA and rejects it if it does not match the A codon. It was suggested that universally conserved G530, A1492 and A1493 of 16S ribosomal RNA, critical for tRNA binding in the A site, actively monitor cognate tRNA, and that recognition of the correct codon-anticodon duplex induces an overall ribosome conformational change (domain closure). Here we propose an integrated mechanism for decoding based on six X-ray structures of the 70S ribosome determined at 3.1-3.4?? resolution, modelling cognate or near-cognate states of the decoding centre at the proofreading step. We show that the 30S subunit undergoes an identical domain closure upon binding of either cognate or near-cognate tRNA. This conformational change of the 30S subunit forms a decoding centre that constrains the mRNA in such a way that the first two nucleotides of the A codon are limited to form Watson-Crick base pairs. When U·G and G·U mismatches, generally considered to form wobble base pairs, are at the first or second codon-anticodon position, the decoding centre forces this pair to adopt the geometry close to that of a canonical C·G pair. This by itself, or with distortions in the codon-anticodon mini-helix and the anticodon loop, causes the near-cognate tRNA to dissociate from the ribosome. 相似文献
38.
Kazantsev A Walker HA Slepko N Bear JE Preisinger E Steffan JS Zhu YZ Gertler FB Housman DE Marsh JL Thompson LM 《Nature genetics》2002,30(4):367-376
Huntington disease is caused by the expansion of a polyglutamine repeat in the Huntingtin protein (Htt) that leads to degeneration of neurons in the central nervous system and the appearance of visible aggregates within neurons. We have developed and tested suppressor polypeptides that bind mutant Htt and interfere with the process of aggregation in cell culture. In a Drosophila model, the most potent suppressor inhibits both adult lethality and photoreceptor neuron degeneration. The appearance of aggregates in photoreceptor neurons correlates strongly with the occurrence of pathology, and expression of suppressor polypeptides delays and limits the appearance of aggregates and protects photoreceptor neurons. These results suggest that targeting the protein interactions leading to aggregate formation may be beneficial for the design and development of therapeutic agents for Huntington disease. 相似文献
39.
Summary In the ascidian endostyle, all fluorescence due to serotonin is localized in the peripheral, iodine-binding area of the endostylar epithelium, which is homologous to the vertebrate thyroid. The amine appears to be stored in granule-containing cells which may correspond to the vertebrate calcitocytes.We are grateful to Dr M.P. Gorbunova for helpful advise and diseussion. 相似文献
40.
Birmingham CL Canadien V Kaniuk NA Steinberg BE Higgins DE Brumell JH 《Nature》2008,451(7176):350-354
Listeria monocytogenes is an intracellular bacterial pathogen that replicates rapidly in the cytosol of host cells during acute infection. Surprisingly, these bacteria were found to occupy vacuoles in liver granuloma macrophages during persistent infection of severe combined immunodeficient (SCID) mice. Here we show that L. monocytogenes can replicate in vacuoles within macrophages. In livers of SCID mice infected for 21 days, we observed bacteria in large LAMP1(+) compartments that we termed spacious Listeria-containing phagosomes (SLAPs). SLAPs were also observed in vitro, and were found to be non-acidic and non-degradative compartments that are generated in an autophagy-dependent manner. The replication rate of bacteria in SLAPs was found to be reduced compared to the rate of those in the cytosol. Listeriolysin O (LLO, encoded by hly), a pore-forming toxin essential for L. monocytogenes virulence, was necessary and sufficient for SLAP formation. A L. monocytogenes mutant with low LLO expression was impaired for phagosome escape but replicated slowly in SLAPs over a 72 h period. Therefore, our studies reveal a role for LLO in promoting L. monocytogenes replication in vacuoles and suggest a mechanism by which this pathogen can establish persistent infection in host macrophages. 相似文献