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排序方式: 共有539条查询结果,搜索用时 46 毫秒
31.
Francesca D’Addio Takuya Ueno Michael Clarkson Baogong Zhu Andrea Vergani Gordon J. Freeman Mohamed H. Sayegh Mohammed Javeed I. Ansari Paolo Fiorina Antje Habicht 《PloS one》2013,8(4)
CD160 is a cell surface molecule expressed by most NK cells and approximately 50% of CD8+ cytotoxic T lymphocytes. Engagement of CD160 by MHC class-I directly triggers a costimulatory signal to TCR-induced proliferation, cytokine production and cytotoxic effector functions. The role of CD160 in alloimmunity is unknown. Using a newly generated CD160 fusion protein (CD160Ig) we examined the role of the novel costimulatory molecule CD160 in mediating CD4+ or CD8+ T cell driven allograft rejection. CD160Ig inhibits alloreactive CD8+ T cell proliferation and IFN-γ production in vitro, in particular in the absence of CD28 costimulation. Consequently CD160Ig prolongs fully mismatched cardiac allograft survival in CD4−/−, CD28−/− knockout and CTLA4Ig treated WT recipients, but not in WT or CD8−/− knockout recipients. The prolonged cardiac allograft survival is associated with reduced alloreactive CD8+ T cell proliferation, effector/memory responses and alloreactive IFN-γ production. Thus, CD160 signaling is particularly important in CD28-independent effector/memory CD8+ alloreactive T cell activation in vivo and therefore may serve as a novel target for prevention of allograft rejection. 相似文献
32.
Laura J. Kelly Andrew R. Leitch James J. Clarkson Sandra Knapp Mark W. Chase 《Evolution; international journal of organic evolution》2013,67(1):80-94
Nicotiana (Solanaceae) provides an ideal system for understanding polyploidization, a pervasive and powerful evolutionary force in plants, as this genus contains several groups of allotetraploids that formed at different times from different diploid progenitors. However, the parental lineages of the largest group of allotetraploids, Nicotiana section Suaveolentes, have been problematic to identify. Using data from four regions of three low‐copy nuclear genes, nuclear ribosomal DNA, and regions of the plastid genome, we have reconstructed the evolutionary origin of sect. Suaveolentes and identified the most likely diploid progenitors by using a combination of gene trees and network approaches to uncover the most strongly supported evidence of species relationships. Our analyses best support a scenario where a member of the sect. Sylvestres lineage acted as the paternal progenitor and a member of either sect. Petunioides or sect. Noctiflorae that also contained introgressed DNA from the other, or a hypothetical hybrid species between these two sections, was the maternal progenitor. Nicotiana exemplifies many of the factors that can complicate the reconstruction of polyploid evolutionary history and highlights how reticulate evolution at the diploid level can add even greater complexity to allopolyploid genomes. 相似文献
33.
Garrett I. Ash Matthew A. Kostek Harold Lee Theodore J. Angelopoulos Priscilla M. Clarkson Paul M. Gordon Niall M. Moyna Paul S. Visich Robert F. Zoeller Thomas B. Price Joseph M. Devaney Heather Gordish-Dressman Paul D. Thompson Eric P. Hoffman Linda S. Pescatello 《PloS one》2016,11(1)
Glucocorticoid receptor (NR3C1) polymorphisms associate with obesity, muscle strength, and cortisol sensitivity. We examined associations among four NR3C1 polymorphisms and the muscle response to resistance training (RT). European-American adults (n = 602, 23.8±0.4yr) completed a 12 week unilateral arm RT program. Maximum voluntary contraction (MVC) assessed isometric strength (kg) and MRI assessed biceps size (cm2) pre- and post-resistance training. Subjects were genotyped for NR3C1 -2722G>A, -1887G>A, -1017T>C, and +363A>G. Men carrying the -2722G allele gained less relative MVC (17.3±1.2vs33.5±6.1%) (p = 0.010) than AA homozygotes; men with -1887GG gained greater relative MVC than A allele carriers (19.6±1.4vs13.2±2.3%) (p = 0.016). Women carrying the -1017T allele gained greater relative size (18.7±0.5vs16.1±0.9%) (p = 0.016) than CC homozygotes. We found sex-specific NR3C1 associations with the muscle strength and size response to RT. Future studies should investigate whether these associations are partially explained by cortisol’s actions in muscle tissue as they interact with sex differences in cortisol production. 相似文献
34.
David A. Norton Laura M. Young Andrea E. Byrom Bruce D. Clarkson Phil O'B. Lyver Matt S. McGlone Nick W. Waipara 《Ecological Management & Restoration》2016,17(3):170-179
If we are to make meaningful and measurable progress in restoring New Zealand's biological heritage by 2050, a range of fundamental issues need to be addressed. These relate not just to restoration science but also to building ecosystem resilience in the wider socio‐economic and cultural context within which restoration occurs. 相似文献
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37.
Definition of a short region of XPG necessary for TFIIH interaction and stable recruitment to sites of UV damage
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Thorel F Constantinou A Dunand-Sauthier I Nouspikel T Lalle P Raams A Jaspers NG Vermeulen W Shivji MK Wood RD Clarkson SG 《Molecular and cellular biology》2004,24(24):10670-10680
XPG is the human endonuclease that cuts 3' to DNA lesions during nucleotide excision repair. Missense mutations in XPG can lead to xeroderma pigmentosum (XP), whereas truncated or unstable XPG proteins cause Cockayne syndrome (CS), normally yielding life spans of <7 years. One XP-G individual who had advanced XP/CS symptoms at 28 years has been identified. The genetic, biochemical, and cellular defects in this remarkable case provide insight into the onset of XP and CS, and they reveal a previously unrecognized property of XPG. Both of this individual's XPG alleles produce a severely truncated protein, but an infrequent alternative splice generates an XPG protein lacking seven internal amino acids, which can account for his very slight cellular UV resistance. Deletion of XPG amino acids 225 to 231 does not abolish structure-specific endonuclease activity. Instead, this region is essential for interaction with TFIIH and for the stable recruitment of XPG to sites of local UV damage after the prior recruitment of TFIIH. These results define a new functional domain of XPG, and they demonstrate that recruitment of DNA repair proteins to sites of damage does not necessarily lead to productive repair reactions. This observation has potential implications that extend beyond nucleotide excision repair. 相似文献
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39.
Williams J Clarkson JM Mills PR Cooper RM 《Applied and environmental microbiology》2003,69(7):4190-4191
We adapted a selective medium, previously developed for reisolation of Trichoderma spp. from soil, for quantitative determination of growth of T. harzianum from commercial Agaricus bisporus composts. This medium enables comparisons of aggressive (sensu inhibition of A. bisporus yield) with nonaggressive T. harzianum groups. The resulting medium contains the antimicrobials chloramphenicol, streptomycin, quintozene, and propamocarb and was highly selective, allowing the recovery of T. harzianum, as viable conidia and hyphal fragments, in compact colonies with the absence of visible microbial contaminants. 相似文献
40.
Effects of Abnormal-Sterol Accumulation on Ustilago maydis Plasma Membrane H+-ATPase Stoichiometry and Polypeptide Pattern
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Accumulation of 14α-methylated sterols or Δ8-sterols in Ustilago maydis affected three aspects of the plasma membrane H+-ATPase. Proton transport was reduced in Δ8-sterol-accumulating samples, due to an altered H+/ATP stoichiometry. ATP hydrolytic activity was increased, but no direct correlation with the extent or type of abnormal sterol accumulated could be drawn. Finally, Western blot analysis with antibodies against yeast PMA1 revealed a second lighter band (99-kDa band) in all samples from abnormal-sterol-accumulating sporidia. The conclusions are that the 99-kDa band and a reduced stoichiometry are directly linked to the presence of abnormal sterols, while changes in hydrolytic activity are linked only indirectly. 相似文献