Pseudomonas syringae pv. tomato DC3000 (Pst DC3000) is a bacterial pathogen of tomato and of the model plants Arabidopsis and Nicotiana benthamiana (N. benthamiana). Like numerous Gram-negative bacterial pathogens of ...Pseudomonas syringae pv. tomato DC3000 (Pst DC3000) is a bacterial pathogen of tomato and of the model plants Arabidopsis and Nicotiana benthamiana (N. benthamiana). Like numerous Gram-negative bacterial pathogens of animals and plants, Pst DC3000 exploits the conserved type III secretion system (TTSS) to deliver multiple virulence effectors directly into the host cells. Type III effectors (T3Es) collectively participate in causing disease, by mechanisms that are not well clarity. Elucidating the virulence function of individual effector is fundamental for understanding bacterial infection of plants. Here, we focused on studying one of these effectors, HopAA1-1, and analyzed its potential function and subcellular localization in N. benthamiana. Using an Agrobacterium-mediated transient expression system, we found that HopAA1-1 can trigger domain-dependent cell death in N. benthamiana. The observation using confocal microscopy showed that the YFP-tagged HopAA1-1 localizes to diverse cellular components containing nucleus, cytoplasm and cell membrane, which was demonstrated through immunoblot analysis of membrane fractionation and nuclear separation. Enforced HopAA1-1 subcellular localization, by tagging with a nuclear localization sequence (NLS) or a nuclear export sequence (NES), shows that HopAA1-1-induced cell death in N. benthamiana is suppressed in the nucleus but enhanced in the cytoplasm. Our research is lay a foundation for revealed the molecular pathogenesis of Pseudomonas syringae pv. tomato.展开更多
文摘Pseudomonas syringae pv. tomato DC3000 (Pst DC3000) is a bacterial pathogen of tomato and of the model plants Arabidopsis and Nicotiana benthamiana (N. benthamiana). Like numerous Gram-negative bacterial pathogens of animals and plants, Pst DC3000 exploits the conserved type III secretion system (TTSS) to deliver multiple virulence effectors directly into the host cells. Type III effectors (T3Es) collectively participate in causing disease, by mechanisms that are not well clarity. Elucidating the virulence function of individual effector is fundamental for understanding bacterial infection of plants. Here, we focused on studying one of these effectors, HopAA1-1, and analyzed its potential function and subcellular localization in N. benthamiana. Using an Agrobacterium-mediated transient expression system, we found that HopAA1-1 can trigger domain-dependent cell death in N. benthamiana. The observation using confocal microscopy showed that the YFP-tagged HopAA1-1 localizes to diverse cellular components containing nucleus, cytoplasm and cell membrane, which was demonstrated through immunoblot analysis of membrane fractionation and nuclear separation. Enforced HopAA1-1 subcellular localization, by tagging with a nuclear localization sequence (NLS) or a nuclear export sequence (NES), shows that HopAA1-1-induced cell death in N. benthamiana is suppressed in the nucleus but enhanced in the cytoplasm. Our research is lay a foundation for revealed the molecular pathogenesis of Pseudomonas syringae pv. tomato.
文摘目的:观察自体DC-CIK细胞联合经皮微波热凝(percutaneous microwave coagulation therapy,PMCT)治疗肝癌的临床疗效。方法:收集2012年1月至2014年2月东方肝胆外科医院生物治疗科收治的44例行PMCT+DC-CIK治疗的肝癌患者(联合治疗组),先行血细胞分离单采并进行DC-CIK细胞培养,采血后第2天进行PMCT治疗;培养10 d后行CIK细胞回输及DC疫苗皮内注射。此后分别于1、2个月后行第2疗程及第3疗程DC-CIK细胞治疗。同时选取44例单纯行PMCT治疗的同期肝癌患者与之配对(对照组),该组患者仅行PMCT治疗。观察两组治疗前后的AFP变化、免疫功能、无进展生存期、总生存期及不良反应。结果:联合治疗组、对照组治疗后均有AFP下降及外周血调节性T细胞降低,但联合治疗组下降程度更显著(P<0.05);对照组治疗后外周血淋巴细胞亚群无明显变化(P>0.05),而联合治疗组则显著升高(P<0.05)。联合治疗组中位无进展生存时间及中位总生存时间均较对照组延长(7.1 vs 4.9个月;21.5 vs 14.0个月,均P<0.05)。结论:自体DC-CIK细胞联合PMCT是治疗肝癌的一种有效方法,可提高患者免疫功能、延缓肿瘤复发、延长生存期,且不良反应较少。
