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1.
为研制抗血吸虫疫苗提供实验依据,探讨了抗血吸虫SjGST-32核酸疫苗与蛋白疫苗联合免疫的免疫增强效应及免疫应答特征。将日本血吸虫DNA疫苗VR1012-SjGST-32与重组蛋白疫苗rSjGST-32分别在第0、2和4周免疫小鼠,在第6周攻击感染日本血吸虫尾蚴,攻击感染45 d后剖杀小鼠,计算减虫率、检卵率以及检测肝脏病理变化,观察免疫保护效果;检测小鼠血清中特异性IgG抗体滴度,T细胞增殖反应和抗原特异性CD4+IFN-γ+、CD4+IL-4+和CD4+IL-10+的数量,探讨免疫应答特征。结果显示,DNA初免-蛋白加强的联合免疫组的保护作用优于单独免疫组,显著提高了减虫率(42.3%)和减卵率(59.6%),并且能够显著减轻血吸虫虫卵对肝脏的病理损害;进一步发现,DNA疫苗和蛋白疫苗联合应用增强了机体T淋巴细胞增殖反应、抗体IgG滴度以及抗原特异性CD4+IFN-γ+的产生。这些研究为新型血吸虫疫苗的优化设计和合理应用提供了依据。 相似文献
2.
Skp2B stimulates mammary gland development by inhibiting REA, the repressor of the estrogen receptor
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Umanskaya K Radke S Chander H Monardo R Xu X Pan ZQ O'Connell MJ Germain D 《Molecular and cellular biology》2007,27(21):7615-7622
Skp2B, an F-box protein of unknown function, is frequently overexpressed in breast cancer. In order to determine the function of Skp2B and whether it has a role in breast cancer, we performed a two-hybrid screen and established transgenic mice expressing Skp2B in the mammary glands. We found that Skp2B interacts with the repressor of estrogen receptor activity (REA) and that overexpression of Skp2B leads to a reduction in REA levels. In the mammary glands of MMTV-Skp2B mice, REA levels are also low. Our results show that in virgin transgenic females, Skp2B induces lobuloalveolar development and differentiation of the mammary glands normally observed during pregnancy. As this phenotype is identical to what was observed for REA heterozygote mice, our observations suggest that the Skp2B-REA interaction is physiologically relevant. However, in contrast to REA(+/-) mice, MMTV-Skp2B mice develop mammary tumors, suggesting that Skp2B affects additional proteins. These results indicate that the observed expression of Skp2B in breast cancer does contribute to tumorigenesis at least in part by modulating the activity of the estrogen receptor. 相似文献
3.
As alternatives of viral and cationic lipid gene carriers, cationic polymer-based vectors may provide flexible chemistry for the attachment of targeting moieties. In this report, galactosylated N-2-hydroxypropyl methacrylamide-b-N-3-guanidinopropyl methacrylamide block copolymers (galactosylated HPMA-b-GPMA block copolymers, or abbreviated as GHG) were prepared in order to develop hepatocyte targeting gene transfection carriers. The block copolymers were synthesized by aqueous reversible addition-fragmentation chain transfer (RAFT) polymerization of N-2-hydroxypropyl methacrylamide (HPMA) and N-3-aminopropyl methacrylamide (APMA), followed by galactosylation and guanidinylation. The molecular weight of GHG copolymers determined by static light scattering method was in the range from 48?600 to 76?240 g/mol. In addition, the galactose content in the GPMA block in the copolymers was determined to be 6.5-8.0 mol % according to the sulfuric acid method. The GHG copolymers complexed completely with plasmid DNA (pDNA) to show positive zeta-potential values with diameter 100-250 nm from charge ratio of 4, which demonstrated the excellent DNA condensing ability of guanidino groups. Furthermore, the MTT assay data of GHG/pDNA complexes on HepG2 cells and HeLa cells indicated that GHG copolymers had significantly lower cytotoxicity than PEI. In addition, the copolymers with GPMA component from 30.23% showed higher transfection efficiency than PEI at charge ratio of 12 in HepG2 cells. The result revealed that the conjugation of galactose groups in the copolymers brought asialoglycoprotein-receptor (ASGP-R) mediated transfection. The employing of HPMA component decreased the aggregation of protein in transfection presence of serum. The GHG copolymers combined the advantages of galactose moieties, guanidino groups, and HPMA component might show potential in safe hepatocyte targeting gene therapy. 相似文献
4.
Xinsong Xu Malik Keshwani Kathleen Meyer Antonio Sarikas Susan Taylor Zhen-Qiang Pan 《The Journal of biological chemistry》2012,287(48):40758-40766
Hyperactivation of mechanistic target of rapamycin complex 1 (mTORC1) and its effector kinase S6 kinase 1 (S6K1) is known to trigger multisite seryl phosphorylation of insulin receptor substrate 1 (IRS1), leading to its ubiquitination and degradation. This negative feedback inhibition functions to restrain PI3K activity and plays critical roles in the pathogenesis of cancer and type II diabetes. Recent work has implicated a role for cullin-RING E3 ubiquitin ligase 7 (CRL7) in targeting IRS1 for mTORC1/S6K1-dependent degradation. In the present study we have employed both cell-based degradation and reconstituted ubiquitination approaches to define molecular features associated with IRS1 critical for CRL7-mediated ubiquitination and degradation. We have mapped IRS1 degradation signal sequence to its N-terminal 574 amino acid residues, of which the integrity of Ser-307/Ser-312 and Ser-527, each constituting a S6K1 phosphorylation consensus site, was indispensible for supporting CRL7-forced degradation. In vitro, S6K1 was able to support the ubiquitination of bacterially expressed IRS1 N-terminal fragment by CRL7 but at low levels. In contrast, CRL7 supported efficient ubiquitination of IRS1 N-terminal fragment in hyperphosphorylated form, which was isolated from infected insect cells, suggesting requirement of additional phosphorylation by kinases yet to be identified. Finally, removal of IRS1 amino acids 1–260 led to substantial reduction of ubiquitination efficiency, suggesting a role for this region in mediating productive interactions with CRL7. The requirement of multisite phosphorylation and the N terminus of IRS1 for its turnover may ensure that complete IRS1 degradation occurs only when mTORC1 and S6K1 reach exceedingly high levels. 相似文献
5.
Galactosylated 2‐hydroxypropyl methacrylamide‐s‐3‐guanidinopropyl methacrylamide copolymer as a small hairpin RNA carrier for inhibiting human telomerase reverse transcriptase expression
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Yang Wu Jingkai Ji Ran Yang Xiaoqiang Zhang Yuanhui Li Yuepu Pu Xinsong Li 《The journal of gene medicine》2014,16(5-6):109-121
6.
醋酸纤维素膜为基础的葡萄糖生物传感器的研制 总被引:4,自引:0,他引:4
用共价法将酶固定在醋酸纤维素膜上,方法简便易行,制造的酶膜稳定,比活力高。同时采用该方法制备了葡萄糖氧化酶酶膜,与氧电极组装成测定葡萄糖的生物传感器,线性范围为50~800mg/dl,仪器工作的最适pH为6.0,最适温度为40℃。将该膜与过氧化氢电极组装得到的传感器具有以下特性:线性范围为10~200mg/dl,最适pH为6.0,测定结果与酶试制盒有良好相关性。 相似文献
7.
Extremely low frequency (ELF) pulsed-gradient magnetic fields inhibit malignant tumour growth at different biological levels 总被引:6,自引:0,他引:6
Extremely low frequency (ELF) pulsed-gradient magnetic field (with the maximum intensity of 0.6-2.0 T, gradient of 10-100 T.M(-1), pulse width of 20-200 ms and frequency of 0.16-1.34 Hz treatment of mice can inhibit murine malignant tumour growth, as seen from analyses at different hierarchical levels, from organism, organ, to tissue, and down to cell and macromolecules. Such magnetic fields induce apoptosis of cancer cells, and arrest neoangiogenesis, preventing a supply developing to the tumour. The growth of sarcomas might be amenable to such new method of treatment. 相似文献
8.
人p53蛋白在巴斯德毕赤酵母中的表达 总被引:9,自引:2,他引:9
将人p53 基因装入 Pichia 分泌型质粒p H I L S1 中,酶切线性化后电穿孔导入酵母细胞进行整合,经筛选得到一高表达p53 蛋白的克隆。 S D S P A G E 显示表达量约占分泌总量的30 % 。 E L I S A 验证重组人p53 存在免疫学活性。在诱导时就降低 Pichia 酵母系统水解酶活力等方面进行优化,经 F P L C 分离纯化得到约200 m g/ L 表达量。 相似文献
9.
辣根过氧化物酶同功酶C基因克隆及其在大肠杆菌中的表达 总被引:3,自引:0,他引:3
无论从应用还是从理论研究角度,辣根过氧化物酶(HRP)是一种非常重要的酶.HRP基因克隆与表达将有利于更深入研究HRP的结构与功能.利用反转录PCR从天然植物辣根中分离和克隆编码辣根过氧化物酶同功酶C(HRP-C)一个cDNA,并测定其序列.结果发现,从基因推导出的氨基酸序列与Welinder报道的辣根过氧化物酶序列有90.6%的同源性.将该基因连接到表达载体pET-24b上,利用抗HRP多克隆抗体进行Westernblot,检测有少量目标产物表达.在诱导表达过程中,没有发现细菌生长受抑制或受明显的毒害 相似文献
10.
Xiaoting Wang Yang Dai Song Zhao Jianxia Tang Hongjun Li Yuntian Xing Guoli Qu Xinsong Li Jianrong Dai Yinchang Zhu Xueguang Zhang 《PloS one》2014,9(1)