流式细胞术不同设门方法对CD4+CD25+调节性T细胞的检测方法比较

目的 比较CD4+CD25hi、CD4+CD25+FoxP3+和CD4+CD25+CD127-/low 3种设门方法对CD4+CD25+调节性T细胞(Treg细胞)的界定效果.方法 完全随机法选择33例本院健康体检者,分别采用CD4+CD25hi、CD4+CD25+FoxP3+和CD4+CD25+CD127-/low设门的方法进行检测.结果 (1)CD4+CD25hi、CD4+CD25+FoxP3+设门方法对CD4+CD25+Treg细胞的检测结果差异无统计学意义[(6.85±2.72)%,(6.69±2.30)%,t=0.270,P=0.788],相关性检验显示,两者呈正相关(r=0.866,P＜0.001);(2)CD4+CD25+CD127-/low设门方法的细胞检测结果[(8.07±2.18)%]高于CD4+CD25hi和CD4+CD25+FoxP3+设门方法(t=2.055,P=0.043;t=2.325,P=0.022),相关性检验显示,均呈正相关(r=0.615,P＜0.001;r=0.683,P＜0.001);(3)CD4+CD25hi细胞群中FoxP3+细胞占(57.11±12.42)%,CD4+CD25hi细胞群中FoxP3+细胞占所有FoxP3+细胞的比例为(54.4±9.0)%.结论 CD4+CD25hi设门方法可用于人外周血CD4+CD25+Treg细胞的检测,CD4+CD25+CD127-/low设门方法可应用于CD4+CD25+Treg细胞的纯化.     

Structure-guided design and immunological characterization of immunogens presenting the HIV-1 gp120 V3 loop on a CTB scaffold

V3 loop is a major neutralizing determinant of the HIV-1 gp120. Using 3D structures of cholera toxin B subunit (CTB), complete V3 in the gp120 context, and V3 bound to a monoclonal antibody (mAb), we designed two V3-scaffold immunogen constructs (V3-CTB). The full-length V3-CTB presenting the complete V3 in a structural context mimicking gp120 was recognized by the large majority of our panel of 24 mAbs. The short V3-CTB presenting a V3 fragment in the conformation observed in the complex with the 447-52D Fab, exhibited high-affinity binding to this mAb. The immunogens were evaluated in rabbits using DNA-prime/protein-boost protocol. Boosting with the full-length V3-CTB induced high anti-V3 titers in sera that potently neutralize multiple HIV virus strains. The short V3-CTB was ineffective. The results suggest that very narrow antigenic profile of an immunogen is associated with poor Ab response. An immunogen with broader antigenic activity elicits robust Ab response.     

三种LT突变体的幽门螺杆菌疫苗黏膜免疫佐剂效应比较

目的 探讨3种大肠杆菌不耐热肠毒素突变体在辅佐幽门螺杆菌候选疫苗尿素酶B亚单位(rUreB)中的佐剂效应.方法 各组Balb/c小鼠分别用PBS、rUreB、rUreB LTK63、rUreB LTR72、rUreB LTKR及rUreB CT进行4次口服免疫.ELISA检测胃、肠、气管冲洗液sIgA以及血清IgG亚类(IgG1,IgGa);RT-PCR差异显示T淋巴细胞IFN-γ、IL-4 mRNA;ELISPOT检测肠派伊尔氏结IgA、IgG抗体分泌细胞.结果 ①各rUREB加突变体佐剂组在胃、肠、气管的sIgA和血清IgG1、IgG2a水平显著高于PBS组和单独rUreB组(P＜0.01);②抗原刺激后取自各rUreB加突变体佐剂组T淋巴细胞表达的IFN-γ、IL-4 mRNA显著高于PBS组和rUreB组(P＜0.01);③各rUreB加突变体佐剂组小肠派伊尔氏结抗体分泌细胞数都显著高于PBS组和单独rUreB组(P＜0.01).结论 3种突变体都能辅佐rUreB在小鼠上产生特异的抗rUreB的抗体,且3种突变体诱导的免疫应答可能都是Th1/Th2型.LTR72的佐剂效应强于LTK63及LTKR.LTKR无毒,其稳定性高于LTR72,佐剂活性高于LTK63,是一个有希望的新型黏膜免疫佐剂.     

幽门螺杆菌napA-ctxB融合蛋白的基因克隆与表达

目的 克隆、表达幽门螺杆菌中性粒细胞激活蛋白napA与霍乱毒素B亚单位ctxB融合基因napA-ctxB(nctB),为制备预防H.pylori感染的疫苗奠定基础.方法 用PCR方法扩增ctxB目的基因片段,克隆至pQE30-napA质粒的napA基因上游,构建含双基因的表达质粒pQE30-napA-ctxB(pQE30-nctB),经测序分析确认后转化E.coli DH5α,经IPTG诱导表达融合蛋白NCTB,融合蛋白NCTB经镍离子柱纯化.结果 PCR扩增出807 bp的目的基因片段nctB.工程菌pQE30-nctB-DH5α经IPTG诱导后,SDS-PAGE显示有新生的蛋白表达条带,Mr为30 000,与预期的一致,约占菌体总蛋白的27%,重组蛋白用Ni2 -NTA 树脂提纯,纯化后的蛋白质经SDS-PAGE分析可见单一条带,图象软件分析表明纯度可达94%以上.Western blot 显示重组蛋白质有良好的抗原性.结论 构建含双基因的表达质粒pQE30-nctB成功,并在大肠杆菌DH5α中高效的表达.     

Vaccination of goats with 31 kDa and 32 kDa Schistosoma japonicum antigens by DNA priming and protein boosting

Two Schistosomajaponicum vaccine candidate antigens Sj 31 and Sj 32, which have shown particular promise to induce protective immunity in mice, were used to immunize goats by using a DNA priming-protein boosting strategy in present work. DNA vaccine formulations of the two antigens （VRSj31 and VRSj32） were produced and injected intramuscularly twice at a 2-week interval and then recombinant proteins （rSj31 and rSj32） together with Freund Complete Adjuvant （FCA） were used to boost the goats. The experiment was repeated in different batche cercariae. A strong anamnestic antibody response was induced after boost. A significant reduction of liver egg counts and miracidial hatching was showed in both experiments. Significant protections against challenge infection were elicited with 31.6% of percentage reduction for worm recovery in the second experiment and 20.9% in the first experiment, respectively.     

Cytoplasmic localization of p27 (cyclin-dependent kinase inhibitor 1B/KIP1) in colorectal cancer: inverse correlations with nuclear p27 loss, microsatellite instability, and CpG island methylator phenotype

Cytoplasmic mislocalization of p27 (CDKN1B/KIP1) is caused by activated AKT1 and has been associated with poor prognosis in various cancers. CIMP in colorectal cancer is characterized by extensive promoter methylation and is associated with MSI-MSI-H and BRAF mutations. We have recently shown a positive correlation between MSI/CIMP and loss of nuclear p27. However, no study has examined cytoplasmic p27 mislocalization in relation to CIMP and MSI in colorectal cancer. Using MethyLight assays, we quantified DNA methylation in 8 CIMP-specific gene promoters (CACNA1G, CDKN2A (p16), CRABP1, IGF2, MLH1, NEUROG1, RUNX3, and SOCS1) in 853 colorectal cancer samples obtained from 2 large prospective cohorts. We assessed expressions of nuclear and cytoplasmic p27 and nuclear p53 by immunohistochemistry. Cytoplasmic p27 expression was inversely associated with loss of nuclear p27 (P < .0001), CIMP-high (P < .0001), MSI-H (P < .0001), and BRAF mutations (P < .0001). The inverse association of cytoplasmic p27 with CIMP-high (or MSI-H) was independent of MSI (or CIMP) status. In addition, the inverse association of cytoplasmic p27 with CIMP-high was independent of KRAS/BRAF status. BRAF and CDKN2A (p16) methylation were not correlated with cytoplasmic p27 after stratification by CIMP status. The inverse associations of cytoplasmic p27 with MSI-H and CIMP-high were much more pronounced in p53-negative than p53-positive tumors. In conclusion, cytoplasmic p27 expression is inversely associated with MSI-H and CIMP-high, particularly in p53-negative tumors, suggesting interplay of functional losses of p27 and p53 in the development of various molecular subtypes of colorectal cancer.     

rCTB和TT为蛋白载体的A群流脑多糖黏膜免疫初步研究

目的 对重组霍乱毒素B亚单位(rCTB)作为多糖蛋白结合疫苗候选载体的可行性进行分析,并对以破伤风类毒素(TT)与rCTB为蛋白载体的黏膜投递型疫茸的免疫效果进行初步探讨.方法 首先通过基因工程手段获得具有五聚体结构的rCTB.再将rCTB五聚体蛋白利用化学方法(ADH方法)与A群脑膜炎球菌多糖(GAMP)耦联,获得多糖蛋白结合物GAMP-rCTB,并将其与TT为蛋白载体的A群流脑多糖蛋白结合物(GAMP-TT)以滴鼻和注射途径免疫BALB/c小鼠,并对其进行免疫学评价.结果 以rCTB和TT为载体的A群流脑多糖蛋白结合物,通过黏膜投递途径均可在血清中产生相对较高的多糖特异性IgG抗体,在肺部盥洗液和小肠黏膜也产生了相应的特异性IgA抗体.结论 rCTB和TT均可作为黏膜投递型多糖结合疫苗的候选蛋白载体.以rCTB为载体的多糖蛋白结合物,黏膜途径可能在免疫功能方面优于注射途径.     

AMPKα2基因shRNA重组质粒的构建以及在氯离子介导的大鼠心肌缺氧/复氧损伤中的作用

 目的：构建AMP活化的蛋白激酶α2亚基(AMPKα2)基因shRNA重组表达质粒,转染H9c2心肌细胞,探讨其在氯离子(Cl^-)介导的心肌细胞缺氧/复氧（A/R）损伤中的作用。方法：构建靶向AMPKα2基因的shRNA重组质粒pSuper-AMPKα2 shRNA,转染H9c2细胞;Western blotting法测定AMPKα2的蛋白表达情况。实验分5组,每组重复6次：(1) Control组;(2) A/R组;(3) Cl^--free A/R组;(4) pSuper+Cl^--free A/R组;(5) pSuper-AMPKα2 shRNA+ Cl^--free A/R组。处理结束后,生化自动分析仪测定LDH活性,MTT法测定细胞存活率,流式细胞术检测细胞凋亡和活性氧（ROS）水平,试剂盒检测细胞内超氧化物歧化酶（SOD）和谷胱甘肽过氧化物酶（GSH-Px）活性。结果：重组表达质粒pSuper-AMPKα2 shRNA经测序证明构建正确;转染心肌细胞后,AMPKα2蛋白表达明显下降;Cl^--free A/R组较之A/R组细胞存活率升高,LDH含量下降,细胞凋亡减少,ROS生成减少,SOD和GSH-Px活性增加;转染pSuper-AMPKα2 shRNA质粒后,阻断了Cl--free液的保护作用,且ROS生成增加,SOD和GSH-Px活性也下降。结论：成功构建pSuper-AMPKα2 shRNA重组质粒。AMPKα2基因沉默阻断了Cl^--free液对心肌细胞A/R损伤的保护作用。     

NMDA receptor/amyloid precursor protein interactions: a comparison between wild-type and amyloid precursor protein mutations associated with familial Alzheimer's disease

Two recent reports showed that amyloid precursor protein (APP) may contribute to postsynaptic mechanisms via the regulation of the surface trafficking of excitatory N-methyl-D-aspartate (NMDA) receptors. Here we have investigated the interactions and surface trafficking of NR1-1a/NR2A and NR1-1a/NR2B NMDA receptor subtypes with three APP mutations linked to familial Alzheimer's disease, APP695(Indiana), APP695(London) and APP695(Swedish). Flag-tagged mutated APP695s were generated and shown to be expressed at equivalent levels to wild-type APP695 in mammalian cells. Each APP mutant co-precipitated with NR1-1a/NR2A and NR1-1a/NR2B receptors following co-expression in mammalian cells. Further, as found for wild-type APP695, each enhanced NMDA receptor surface expression with no concomitant increase in total NR1-1a, NR2A or NR2B subunit expression. Thus these three familial APP mutations behave as wild-type APP695 with respect to their association with assembled NMDA receptors and their APP695-enhanced receptor cell surface trafficking.