钩端螺旋体外膜疫苗的流行病学效果评价

为了评价国产钩端螺旋体外膜疫苗的流行病学效果。于1998年6－10月,用队列研究和病例对照研究等方法在钩体病流行区5－60岁农业人口 ,观察比较接种组和对照组钩体发病情况。队列研究显示,钩体外膜疫苗对同血清群钩体的保护率为75．17％,效果指烽为4．03。1：2配对调查的疫苗保护率为81．25％,1：3配对结果为73．33％。用筛选法估计的疫苗效果为755。不同研究方法的结果相近,均一致说明,该疫苗的流行病学效果较理想。研究结果还显示,该疫苗对异血清群钩体也有一定的保护作用。     

口服型HCV融合抗原DNA疫苗在小鼠诱导免疫应答

将编码一个外源信号肽、一个通用型辅助性T淋巴细胞抗原表位和HCV核心 包膜蛋白E2融合抗原基因的真核表达质粒pST CE2t(DNA疫苗 )转化到减毒鼠伤寒沙门菌SL72 0 7.将该重组菌口服接种BALB c小鼠 3次 .小鼠的抗HCV核心和E2抗体阳转率分别达 6 0 %和 70 % .体外以重组HCV核心或E2抗原刺激小鼠脾细胞 ,均使之发生明显的增殖反应 ,且小鼠脾细胞能有效杀伤表达HCV核心抗原的同系骨髓瘤细胞SP2 0 .这为研制高效免疫、成本低廉、接种方便的HCV疫苗提供了一个新的可行途径     

鸡发育过程肌组织核提抽物结合活性与AChRγ亚基基因持续表达的关系

烟碱样乙酰胆碱受体 ( n ACh R)是由 4种亚基组成的五聚体 .哺乳类动物出生后γ亚基由ε亚基取代 ,迄今为止鸡 n ACh Rγ基因是否存在上述置换规律尚无定论 .为探索发育过程鸡骨骼肌n ACh R基因表达是否存在γ/ε亚基的置换及其机制 ,采用 RT- PCR技术和凝胶阻滞试验检测了鸡胚发育 9d至出生后 6周小鸡 γ基因表达的动力学及骨骼肌核抽提物的 DNA结合活性 .RT-PCR检测结果显示 ,在鸡胚发育 9d至出生后 6周的雏鸡骨骼肌组织均检出有 γ亚基 m RNA转录 .提示与哺乳类不同 ,出生前后鸡骨骼肌组织 ACh Rγ亚基基因持续表达 ,不存在 γ/ε亚基的置换表达规律 .以 γ基因 - 2 60 /- 2 4 0 (含 E盒与 M- CAT盒重叠序列 )和 - 2 39/- 50 (含 M- CAT盒及 GC富含区 )片段为探针 ,分别与鸡胚发育 9d至出生后 2周小鸡骨骼肌的核抽提物进行凝胶阻滞试验 .在发育各阶段的骨骼肌核抽提物中均有识别 - 2 39/- 50片段的结合活性存在 ,但在出生后 2周小鸡骨骼肌的核抽提物中未检出 - 2 60 /- 2 4 0结合活性 .结果提示 ,在出生后第 1 4d的肌核抽提物中存在的、识别并结合 - 2 39/- 50片段的活性物质与鸡 ACh Rγ基因在出生后持续表达有关 .     

HBV包膜-核心蛋白融合基因DNA疫苗诱导小鼠持久的细胞免疫应答

构建编码HBV包膜-核心蛋白融合基因的DNA疫苗pSC、pSS1S2C和编码HBV包膜蛋白或核心蛋白基因的DNA疫苗pHBs、pHBc,分别肌肉注射免疫BALB/c小鼠,检测小鼠的血清抗体、T细胞增殖和细胞毒性T淋巴细胞反应,比较融合基因DNA疫苗与单基因DNA疫苗诱生免疫应答的强度,发现融合基因DNA疫苗诱生抗体的效率明显不及单基因DNA疫苗,但其能诱导更强、更持久的细胞免疫应答,表明HBV包膜-核心蛋白融合基因DNA疫苗对于治疗慢性乙型肝炎可能比单基因DNA疫苗更为有效.     

Cholesterol trafficking and raft-like membrane domain composition mediate scavenger receptor class B type 1-dependent lipid sensing in intestinal epithelial cells

Scavenger receptor Class B type 1 (SR-B1) is a lipid transporter and sensor. In intestinal epithelial cells, SR-B1-dependent lipid sensing is associated with SR-B1 recruitment in raft-like/ detergent-resistant membrane domains and interaction of its C-terminal transmembrane domain with plasma membrane cholesterol. To clarify the initiating events occurring during lipid sensing by SR-B1, we analyzed cholesterol trafficking and raft-like domain composition in intestinal epithelial cells expressing wild-type SR-B1 or the mutated form SR-B1-Q445A, defective in membrane cholesterol binding and signal initiation. These features of SR-B1 were found to influence both apical cholesterol efflux and intracellular cholesterol trafficking from plasma membrane to lipid droplets, and the lipid composition of raft-like domains. Lipidomic analysis revealed likely participation of d18:0/16:0 sphingomyelin and 16:0/0:0 lysophosphatidylethanolamine in lipid sensing by SR-B1. Proteomic analysis identified proteins, whose abundance changed in raft-like domains during lipid sensing, and these included molecules linked to lipid raft dynamics and signal transduction. These findings provide new insights into the role of SR-B1 in cellular cholesterol homeostasis and suggest molecular links between SR-B1-dependent lipid sensing and cell cholesterol and lipid droplet dynamics.     

卵透明带ZP3的研究及其应用

卵透明带蛋白围绕在卵母细胞外,在受精过程中起着重要作用。ZP3蛋白是卵透明带蛋白家族中的重要成员,在功能上,ZP3作为初级精子受体,起始精卵结合和顶体反应。由于ZP3在受精中的重要作用,它成为免疫避孕的有效靶点。ZP3蛋白疫苗和DNA疫苗可以诱导机体产生较强的免疫反应,导致生育降低,同时带来一定程度的副作用。本文重点介绍了ZP3的免疫特性及其应用。     

Highly Sensitive Assay for Measurement of Arenavirus-cell Attachment

Arenaviruses are a family of enveloped RNA viruses that cause severe human disease. The first step in the arenavirus life cycle is attachment of viral particles to host cells. While virus-cell attachment can be measured through the use of virions labeled with biotin, radioactive isotopes, or fluorescent dyes, these approaches typically require high multiplicities of infection (MOI) to enable detection of bound virus. We describe a quantitative (q)RT-PCR-based assay that measures Junin virus strain Candid 1 attachment via quantitation of virion-packaged viral genomic RNA. This assay has several advantages including its extreme sensitivity and ability to measure attachment over a large dynamic range of MOIs without the need to purify or label input virus. Importantly, this approach can be easily tailored for use with other viruses through the use of virus-specific qRT-PCR reagents. Further, this assay can be modified to permit measurement of particle endocytosis and genome uncoating. In conclusion, we describe a simple, yet robust assay for highly sensitive measurement of arenavirus-cell attachment.     

Effect of a DNA vaccine harboring two copies of inhibin α (1-32) fragments on immune response, hormone concentrations and reproductive performance in rats

The objective was to investigate the effects of a novel DNA vaccine (pcISI) harboring two copies of inhibin α (1-32) fragments on immune response, hormone concentrations and reproductive performance in rats. Female Wistar rats (n = 18 per group) were immunized (twice, 4 wk apart) with 10, 50, or 100 μg (T₁, T₂ and T₃, respectively), of the pcISI plasmid. At 4 wk after the second immunization, plasma antibody titers were higher (P < 0.05) in T₃ than in either T₁ or T₂ (0.341 ± 0.123, 0.236 ± 0.068, and 0.251 ± 0.077, respectively, mean ± SD). Concurrrently, plasma concentrations of FSH and estradiol were highest (P < 0.05) in T₃, and were higher (P < 0.05) in T₁ and T₂ than in control groups. For antibody-positive rats, there was a correlation (P < 0.01) between antibody titer and FSH concentrations after two pcISI immunizations. The number of mature follicles in the T₃ group (46.00 ± 4.65) was higher (P < 0.05) than in two control groups (29.25 ± 3.72 and 27.92 ± 3.48), and also higher (P < 0.05) than in T₁ and T₂ (37.17 ± 4.99 and 38.75 ± 7.09). Antibody-positive rats had more mature ovarian follicles than negative rats (46.75 ± 4.23 vs. 35.60 ± 3.38, P < 0.05). Moreover, litter size and number of placentas were increased (P < 0.05) in the pcISI immunization groups, except for the T₁ group, compared to the control groups. In conclusion, the pcISI DNA vaccine successfully induced a humoral immune response, improved reproductive hormone concentrations, stimulated follicular development, and increased number of placentas and litter size. Furthermore, 100 μg yielded the best immune response.     

肠毒素大肠杆菌定居因子CS6抗原基因在痢疾杆菌中的表达

通过体外重组的方法,将asd基因插入重组表达质粒,使抗生素抗性失活,并与弗氏志贺氏菌FWL01构成宿主-载体平衡致死系统. 通过蛋白质印迹结果表明,在没有抗生素条件选择的情况下,可稳定表达肠毒素大肠杆菌定居因子抗原CS6. 重组菌通过口服和鼻饲免疫小鼠后,可以诱生CS6血清IgG抗体;同时可以检测到分泌型IgA产生,表明重组菌可以诱导相应的黏膜免疫反应.