Toll-like receptor 4-dependent activation of dendritic cells by beta-defensin 2   总被引：1，自引：0，他引：1  

Biragyn A  Ruffini PA  Leifer CA  Klyushnenkova E  Shakhov A  Chertov O  Shirakawa AK  Farber JM  Segal DM  Oppenheim JJ  Kwak LW 《Science (New York, N.Y.)》2002,298(5595):1025-1029

beta-Defensins are small antimicrobial peptides of the innate immune system produced in response to microbial infection of mucosal tissue and skin. We demonstrate that murine beta-defensin 2 (mDF2beta) acts directly on immature dendritic cells as an endogenous ligand for Toll-like receptor 4 (TLR-4), inducing up-regulation of costimulatory molecules and dendritic cell maturation. These events, in turn, trigger robust, type 1 polarized adaptive immune responses in vivo, suggesting that mDF2beta may play an important role in immunosurveillance against pathogens and, possibly, self antigens or tumor antigens.  相似文献   

The structure of a human p110alpha/p85alpha complex elucidates the effects of oncogenic PI3Kalpha mutations     

Huang CH  Mandelker D  Schmidt-Kittler O  Samuels Y  Velculescu VE  Kinzler KW  Vogelstein B  Gabelli SB  Amzel LM 《Science (New York, N.Y.)》2007,318(5857):1744-1748

PIK3CA, one of the two most frequently mutated oncogenes in human tumors, codes for p110alpha, the catalytic subunit of a phosphatidylinositol 3-kinase, isoform alpha (PI3Kalpha, p110alpha/p85). Here, we report a 3.0 angstrom resolution structure of a complex between p110alpha and a polypeptide containing the p110alpha-binding domains of p85alpha, a protein required for its enzymatic activity. The structure shows that many of the mutations occur at residues lying at the interfaces between p110alpha and p85alpha or between the kinase domain of p110alpha and other domains within the catalytic subunit. Disruptions of these interactions are likely to affect the regulation of kinase activity by p85 or the catalytic activity of the enzyme, respectively. In addition to providing new insights about the structure of PI3Kalpha, these results suggest specific mechanisms for the effect of oncogenic mutations in p110alpha and p85alpha.  相似文献   

Physiological analysis of growth and nitrogen metabolism of intercropped pasture species subterranean clover (Trifolium subterraneum L.) and cocksfoot (Dactylis glomerata L.) supplemented with different forms of inorganic nitrogen     

Viliana Vasileva  Konstantina Kocheva  Janet Mincheva  Georgi Georgiev  Anna Ilieva  Claudio Porqueddu 《Journal of plant nutrition》2017,40(15):2116-2126

Growth and physiological parameters of intercropped subterranean clover (Trifolium subterraneum L.) and cocksfoot (Dactylis glomerata L.) were investigated under controlled and field conditions. Nitrogen nutrition was accomplished in symbiotic and heterotrophic forms in both the species studied under controlled concentration of mineral elements in the media and by in oculation with appropriate rhizobial strain. Intercropped variants were also grown in sand culture as follows: subterranean clover – 100%, cocksfoot – 100%, subterranean clover:cocksfoot– 75:25(%), subterranean clover: cocksfoot– 50:50(%), and subterranean clover:cocksfoot– 25:75(%). In hydroponic cultures, subterranean clover to cocksfoot proportion was always 50:50(%). Subterranean clover reacted positively with growth up to 1.25 mM nitrate concentration in the medium with stimulation of number of nodules formed and their nitrogenase activity. When separately grown, both subclover and cocksfoot reacted with higher plant biomass formation under higher nitrate nutrition. When intercropped, the process of growth stimulation in subclover was more prominent than in cocksfoot.  相似文献