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排序方式: 共有47条查询结果,搜索用时 31 毫秒
31.
CD1d-lipid-antigen recognition by the semi-invariant NKT T-cell receptor   总被引:2,自引:0,他引:2  
The CD1 family is a large cluster of non-polymorphic, major histocompatibility complex (MHC) class-I-like molecules that bind distinct lipid-based antigens that are recognized by T cells. The most studied group of T cells that interact with lipid antigens are natural killer T (NKT) cells, which characteristically express a semi-invariant T-cell receptor (NKT TCR) that specifically recognizes the CD1 family member, CD1d. NKT-cell-mediated recognition of the CD1d-antigen complex has been implicated in microbial immunity, tumour immunity, autoimmunity and allergy. Here we describe the structure of a human NKT TCR in complex with CD1d bound to the potent NKT-cell agonist alpha-galactosylceramide, the archetypal CD1d-restricted glycolipid. In contrast to T-cell receptor-peptide-antigen-MHC complexes, the NKT TCR docked parallel to, and at the extreme end of the CD1d-binding cleft, which enables a lock-and-key type interaction with the lipid antigen. The structure provides a basis for the interaction between the highly conserved NKT TCR alpha-chain and the CD1d-antigen complex that is typified in innate immunity, and also indicates how variability of the NKT TCR beta-chain can impact on recognition of other CD1d-antigen complexes. These findings provide direct insight into how a T-cell receptor recognizes a lipid-antigen-presenting molecule of the immune system.  相似文献   
32.
Psoriasis (OMIM 177900) is a chronic inflammatory skin disorder of unknown pathogenesis affecting approximately 2% of the Western population. It occurs more frequently in individuals with human immunodeficiency virus, and 20-30% of individuals with psoriasis have psoriatic arthritis. Psoriasis is associated with HLA class I alleles, and previous linkage analysis by our group identified a second psoriasis locus at 17q24-q25 (PSORS2; ref. 7). Linkage to this locus was confirmed with independent family sets. Additional loci have also been proposed to be associated with psoriasis. Here we describe two peaks of strong association with psoriasis on chromosome 17q25 separated by 6 Mb. Associated single-nucleotide polymorphisms (SNPs) in the proximal peak lie in or near SLC9A3R1 (also called EBP50 and NHERF1) and NAT9, a new member of the N-acetyltransferase family. SLC9A3R1 is a PDZ domain-containing phosphoprotein that associates with members of the ezrin-radixin-moesin family and is implicated in diverse aspects of epithelial membrane biology and immune synapse formation in T cells. The distal peak of association is in RAPTOR (p150 target of rapamycin (TOR)-scaffold protein containing WD-repeats). Expression of SLC9A3R1 is highest in the uppermost stratum Malpighi of psoriatic and normal skin and in inactive versus active T cells. A disease-associated SNP lying between SLC9A3R1 and NAT9 leads to loss of RUNX1 binding. This is the second example of loss of a RUNX1 binding site associated with susceptibility to an autoimmune disease. It also suggests defective regulation of SLC9A3R1 or NAT9 by RUNX1 as a susceptibility factor for psoriasis.  相似文献   
33.
MicroRNAs (miRNAs) are a family of non-coding RNAs that play crucial roles in regulating various normal cellular responses. Recent studies revealed that the canonical miRNA biogenesis pathway is subject to sophisticated regulation. Hormonal control of miRNA biogenesis by androgen and estrogen has been demonstrated, but the direct effects of the glucocorticoid receptor (GR) on miRNA biogenesis are unknown. This study revealed the role of GR in miRNA maturation. We showed that two GR agonists, dexamethasone and ginsenoside-Rg1 rapidly suppressed the expression of mature miR-15b, miR-23a, and miR-214 in human endothelial cells. RNA pulldown coupled with proteomic analysis identified GTPase-activating protein (SH3 domain) binding protein 1 (G3BP1) as one of the RNA-binding proteins mediating GR-regulated miRNA maturation. Activated GR induced phosphorylation of v-AKT Murine Thymoma Viral Oncogene Homologue (AKT) kinase, which in turn phosphorylated and promoted nuclear translocation of G3BP1. The nuclear G3BP1 bound to the G3BP1 consensus sequence located on primary miR-15b~16-2 and miR-23a~27a~24-2 to inhibit their maturation. The findings from this study have advanced our understanding of the non-genomic effects of GR in the vascular system.  相似文献   
34.
35.
The present study investigated nurses'colour prefer-ences on their uniform in paediatric wards.Results ofthe study provided guidelines for the selecting of ap-propriate colours for nurses'uniforms for paediatricwards,and the comparison of nurses'preferences ofcolours on their uniform and child patients'colourpreferences of nurses'uniform was drawn.  相似文献   
36.
This paper describes a manikin (also known as mannequin) to simulate the thermal physiology of premature infants and experiments performed on it.The performance of the manikin is shown to compare well with that a selection of premature infants in terms of their rate of heat loss.  相似文献   
37.
There has recently been great interest in ablative photodecomposition(APD), notably in pulsed UV laser treatment on polymers, for modification of physical and chemical properties, such as dyeability, printability, adhesion, Iuster and many more. Very little attention was focused, however, on the property of wetting behaviour,which is one of the most fundamental properties in affecting polymer science. Poly(ethylene terephthalate) (PET) fibers drawn to two different draw ratios and under two temperatures, and three white knitted polyester fabrics made of 100% PET fibre were used to investigate their wetting behaviour due to excimer laser treatment.Experiments like water contact angle measurement, vertical drop test and moisture regain were conducted upon samples and all results give the same conclusion that laser treatment increases the hydrophobicity of all samples tested. Scanning electron microscope (SEM) observation reveals how the morphological modification of polymers by laser treatment is correlate  相似文献   
38.
Avoiding false positives with PCR   总被引:315,自引:0,他引:315  
S Kwok  R Higuchi 《Nature》1989,339(6221):237-238
The exquisite sensitivity of the polymerase chain reaction means DNA contamination can ruin an entire experiment. Tidiness and adherence to a strict set of protocols can avoid disaster.  相似文献   
39.
Kwok S 《Nature》2004,430(7003):985-991
Recent isotopic analysis of meteorites and interplanetary dust has identified solid-state materials of pre-solar origin. We can now trace the origin of these inorganic grains to the circumstellar envelopes of evolved stars. Moreover, organic (aromatic and aliphatic) compounds have been detected in proto-planetary nebulae and planetary nebulae, which are the descendants of carbon stars. This implies that molecular synthesis is actively happening in the circumstellar environment on timescales as short as several hundred years. The detection of stellar grains in the Solar System suggests that they can survive their journey through the interstellar medium and that they are a major contributor of interstellar grains.  相似文献   
40.
立体视频编码中的关键问题之一就是视差估值.文中利用分层复数吏登变换域相位相关方法进行匹配提出了一种新的视差估值方法.理论分析和仿真试验证明,本文中的方法克服了传统方法的缺点,提高了视差场的平滑度,减少了视差估值的计算负荷.  相似文献   
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