猪带绦虫六钩蚴TSO45W基因工程疫苗研究进展

囊虫病是一种危害严重的人兽共患寄生虫病。研制有保护性作用的疫苗将是控制和消灭该病的有效方法,猪带绦虫保护性抗原的研究是猪囊虫病免疫的基础。45W蛋白是猪带绦虫六钩蚴时期的重要抗原,但天然45W抗原来源有限,限制了其应用,而基因工程重组抗原的应用可解决质量控制和抗原来源的问题。本文就近年来国内外对猪带绦虫六钩蚴TSO45W基因工程疫苗的研究进展作一综述。     

猪带绦虫重组双歧杆菌疫苗不同保存条件下的稳定性研究

目的 研究猪带绦虫TSO45W-4B基因、TSOL18基因和TSO45W-4B-TSOL18融合基因的重组双歧杆菌(Bb)疫苗在不同保存条件下的稳定性。方法 分别将猪带绦虫重组质粒pGEX-TSO45W-4B、pGEX-TSOL18和pGEX-TSO45W-4B-TSOL18电转入长双歧杆菌(B.longum),获得阳性菌株pGEX-TSO45W-4B/B.longum、pGEX-TSOL18/B.longum和pGEX-TSO45W-4B-TSOL18/B.longum,分别置于不同条件下保存,取出菌液,抽提质粒,电泳检测,进行稳定性分析。结果 阳性菌株pGEX-TSO45W-4B/B.longum、pGEX-TSOL18/B.longum和pGEX-TSO45W-4B-TSOL18/B.longum分别在常温下、4 ℃、-20 ℃、-80 ℃、-196 ℃(液氮中)分别保存48 h、1周、1月、2月,抽提质粒,电泳发现阳性菌株pGEX-TSO45W-4B/B.longum、pGEX-TSOL18/B.longum和pGEX-TSO45W-4B-TSOL18/B.longum在液氮中、-80 ℃、-20 ℃中比较稳定,而在普通的室温环境下,很快发生质粒丢失现象。结论 猪带绦虫TSO45W-4B基因、TSOL18基因和TSO45W-4B-TSOL18融合基因的重组Bb疫苗低温保存最稳定,常温最差,这为猪带绦虫重组Bb疫苗的进一步研究奠定了基础。     

猪带绦虫重组Bb(pGEX-TSO45W-4B-TSOL18)疫苗的构建及鉴定

目的构建和鉴定猪带绦虫重组双歧杆菌(Bb)(pGEX-TSO45W-4B-TSOL18)疫苗。方法用疏水甘氨酸接头连接TSO45W-4B和TSOL18编码基因,通过全基因合成方法合成猪带绦虫TSO45W-4B-TSOL18融合基因。将该融合基因定向克隆到大肠埃希菌-双歧杆菌穿梭表达载体pGEX-1λT中,构建重组质粒pGEX-TSO45W-4B-TSOL18。电穿孔法将该质粒导入Bb,构建猪带绦虫重组Bb(pGEX-TSO45W-4B-TSOL18)疫苗,从具有氨苄青霉素抗性的rBb中抽提质粒进行酶切、PCR和测序鉴定。结果全基因合成789bp的TSO45W-4B-TSOL18融合基因片段。从具有氨苄青霉素抗性的rBb中抽提质粒pGEX-TSO45W-4B-TSOL18,经BamHⅠ和EcoRⅠ双酶切得到4 944bp的pGEX-1λT载体片段和789bp的TSO45W-4B-TSOL18融合基因片段,与预期结果相符;以该重组质粒为模板进行PCR扩增得到789bp的TSO45W-4B-TSOL18融合基因片段,经测序基因片段为789bp,与预期大小相符。结论成功构建了猪带绦虫重组Bb(pGEX-TSO45W-4B-TSOL18)疫苗,为该疫苗的表达及免疫原性研究奠定了基础。     

Antibody responses and epitope specificities to the Taenia solium cysticercosis vaccines TSOL18 and TSOL45-1A

Taenia solium is a cestode parasite that causes cysticercosis in humans and pigs. This study examined the antibody responses in pigs immunized with the TSOL18 and TSOL45-1A recombinant vaccines against T. solium cysticercosis. Immunization with these proteins induced specific, complement-fixing antibodies against the recombinant antigens that are believed to be associated with vaccine-induced protection against T. solium infection. Sera from immunized pigs were used to define the linear B-cell epitopes of TSOL18 and TSOL45-1A. Prominent reactivity was revealed to one linear epitope on TSOL18 and two linear epitopes on TSOL45-1A. These, and oncosphere antigens from other taeniid cestodes, contain a protein sequence motif suggesting that they may show a tertiary structure similar to the fibronectin type III domain (FnIII). Comparison of the location of linear antigenic epitopes in TSOL18 and TSOL45-1A within the proposed FnIII structure to those within related cestode vaccine antigens reveals conservation in the positioning of the epitopes between oncosphere antigens from different taeniid species.     

猪带绦虫TSO45W-4B-TSOL18融合基因在长双歧杆菌中的表达

目的 在成功构建猪带绦虫大肠杆菌-双歧杆菌穿梭表达质粒pGEX-TSO45W-4B-TSOL18的基础上,研究猪带绦虫TSO45W-4B-TSOL18融合基因在长双歧杆菌中的表达情况。方法 将猪带绦虫大肠杆菌-双歧杆菌穿梭表达质粒pGEX-TSO45W-4B-TSOL18电转化入长双歧杆菌, IPTG诱导表达,SDS-PAGE和Western blot分析表达情况。结果 酶切、PCR和测序证实,重组质粒pGEX-TSO45W-4B-TSOL18成功转入长双歧杆菌。SDS-PAGE显示,重组蛋白相对分子质量(M_r)约为55 kD,与预期结果相一致。Western blot显示,重组蛋白能被兔抗血清、囊虫病猪血清和囊虫病患者血清所识别。结论 猪带绦虫TSO45W-4B-TSOL18融合基因能够在长双歧杆菌中获得表达,表达的重组蛋白具有特异的抗原性。     

猪带绦虫六钩蚴TSO18基因研究进展

猪囊尾蚴病是一种严重危害人类健康的人兽共患寄生虫病,疫苗是预防控制猪囊尾蚴病的重要手段.TSO18基因是猪带绦虫六钩蚴阶段重要的免疫原基因,被认为是最具有前途的疫苗候选基因.该文综述了猪带绦虫六钩蚴TSO18基因的分子生物学及其疫苗开发的研究进展.     

猪带绦虫重组双歧杆菌疫苗人工传代后的稳定性研究

目的研究猪带绦虫TSO45W-4B基因、TSOL18基因和TSO45W-4B-TSOL18融合基因重组双歧杆菌(Bb)疫苗人工传代后的稳定性。方法分别将猪带绦虫重组质粒pGEX-TSO45W-4B、pGEX-TSOL18和pGEX-TSO45W-4B-TSOL18电转入长双歧杆菌(Bifidobacteria longum),获得阳性菌株pGEX-TSO45W-4B/Bl、pGEX-TSOL18/Bl和pGEX-TSO45W-4B-TSOL18/Bl,分别经人工传代10次后抽提质粒,进行PCR鉴定和稳定性分析。结果经PCR鉴定,从第7代开始,pGEX-TSOL18/Bl菌株出现质粒丢失的现象,随着培养时间的延长,质粒丢失现象越来越严重,第8代,第9代均出现丢失现象。而pGEX-TSO45W-4B/Bl菌株从第8代开始出现质粒丢失现象,随后的第9代,第10代也陆续出现丢失现象。pGEX-TSO45W-4B-TSOL18/Bl菌株相对稳定,但从第10代开始,开始出现了质粒丢失现象。结论重组质粒转化菌pGEX-TSO45W-4B/Bl、pGEX-TSOL18/Bl和pGEX-TSO45W-4B-TSOL18/Bl人工培养时分别从人工传代培养第8代、第7代和第10代开始出现质粒丢失现象,可稳定遗传7代、6代和9代,显示具有不同程度的遗传稳定性,这为猪带绦虫重组Bb疫苗的进一步研究奠定了基础。     

猪带绦虫45W蛋白疫苗的研制现状

猪囊尾蚴病是一种严重危害人类健康的人兽共患寄生虫病,主要流行于中非、南非、拉丁美洲、东亚和南亚等地区。采用疫苗防治该病是当前研究的热点。本文对45W蛋白的起源、编码基因和45W蛋白疫苗等方面的研究现状进行了综述。     

猪带绦虫TSO45W-4BX与猪CD58分子在大肠埃希菌中的联合表达

目的 以猪CD58为分子佐剂，将CD58基因与猪带绦虫疫苗候选抗原基因TSO45W-4BX联合表达，寻找新型抗猪囊尾蚴疫苗。 方法 分别以重组质粒pGEM-4B和pGEM-CD58为模板，PCR扩增猪带绦虫TSO45W-4BX基因和猪CD58基因，将TSO45W-4BX与酶切处理的pGEX-4T-1定向连接，转化大肠埃希菌JM109，重组质粒经鉴定正确后，在其下游酶切插入CD58基因，PCR扩增和测序证明阅读框正确后，用异丙基-β-D-硫代半乳糖苷（IPTG）诱导表达，用十二烷基磺酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE））和蛋白质印迹法（Western blotting）分析表达产物的免疫活性。 结果 pGEX-4BX和pGEX-4BX/CD58分别表达Mr 41 000和Mr 69 000的融合蛋白，pGEX-4BX表达产物主要以可溶性形式存在，而pGEX-4BX/CD58却以包涵体形式存在，但两者都能被囊尾蚴病患者血清识别。 结论 TSO45W-4BX与CD58基因联合表达，TSO45W-4BX仍具有免疫活性。     

猪带绦虫TSO45W-4BX与猪CD58分子在大肠埃希菌中的联合表达

目的以猪CD58为分子佐剂,将CD58基因与猪带绦虫疫苗候选抗原基因TSO45W-4BX联合表达,寻找新型抗猪囊尾蚴疫苗。方法分别以重组质粒pGEM-4B和pGEM-CD58为模板,PCR扩增猪带绦虫TSO45W-4BX基因和猪CD58基因,将TSO45W-4BX与酶切处理的pGEX-4T-1定向连接,转化大肠埃希菌JM109,重组质粒经鉴定正确后,在其下游酶切插入CD58基因,PCR扩增和测序证明阅读框正确后,用异丙基-β-D-硫代半乳糖苷(IPTG)诱导表达,用十二烷基磺酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE))和蛋白质印迹法(Westernblotting)分析表达产物的免疫活性。结果pGEX-4BX和pGEX-4BX/CD58分别表达Mr41000和Mr69000的融合蛋白,pGEX-4BX表达产物主要以可溶性形式存在,而pGEX-4BX/CD58却以包涵体形式存在,但两者都能被囊尾蚴病患者血清识别。结论TSO45W-4BX与CD58基因联合表达,TSO45W-4BX仍具有免疫活性。     

Multiple genotypes of Taenia solium--ramifications for diagnosis,treatment and control

Mitochondrial DNA sequences of Taenia solium have fully been analyzed. Analysis of the full length of cytochrome c oxidase subunit 1 (1620 bp) and cytochrome b (1068 bp) genes of T. solium, isolated from Asia (China, Thailand, Indonesia and India), from Latin America (Mexico, Ecuador, Bolivia, Peru and Brazil) and from Africa (Tanzania, Mozambique and Cameroon), has revealed that the two phylogenies obtained were similar to each other regardless of the genes examined. The isolates from Asia formed a single cluster, whereas those from Latin America combined with those from Africa to form an additional cluster. It was estimated that these two genotypes emerged approximately 4-8 x 10(5) years ago. These results together with recent study of the ancient of human taeniid cestodes emerged several MYA in Africa, historical data on swine domestication, distribution of pigs and colonization patterns suggest that T. solium was introduced recently into Latin America and Africa from different regions of Europe during the colonial age, which started 500 years ago, and that T. solium of another origin independently spread in Asian countries, perhaps from China. Why did not T. solium of European origin invade or spread into Asia during the colonial age? Analysis of T. solium distribution must include other Taenia species, especially T. saginata and T. asiatica, which can not be differentiated from each other morphologically. BESS T-base analysis for differentiation of all human Taenia species including the two genotypes of T. solium, and T. saginata and T. asiatica has also been characterized. BESS T-base analysis differentiates African isolates from Latin American isolates as well but more samples should be analyzed for obtaining conclusive evidence for the latter. Serological analysis of cyst fluid of T. solium cysticerci obtained in China and Indonesia and from Mozambique and Ecuador indicates geographical differences in their banding patterns. These differences are discussed in the light of possible differences in pathology of T. solium worldwide. As it has been speculated that the ancient T. solium emerged several million years ago in Africa, it is necessary to analyze more isolates from Africa. Such working hypothesis may be evaluated combined with symptomatology and serology when we get additional DNA data from such areas, since there are some varieties of manifestation of neurocysticercosis with or without subcutaneous cysticercosis and of antigens of cyst fluid of T. solium from Asia and from Africa and/or America. Transfer of techniques of molecular identification and sero- and immuno-diagnoses between researchers and technicians from endemic countries using their own materials should be promoted with the aim of better international cooperation for the control of cysticercosis.     

猪带绦虫囊尾蚴与亚洲带绦虫囊尾蚴蛋白双向电泳图谱分析

将2头20日龄三元杂交乳猪分别感染猪带绦虫虫卵和亚洲带绦虫虫卵,8×104个/头。感染后40 d分别收集寄生在肝脏的未成熟猪带绦虫囊尾蚴(简称猪囊尾蚴)和亚洲带绦虫囊尾蚴,制备囊尾蚴蛋白,并进行蛋白双向电泳分析,用ImageMaster 2D Plantinum 6.0软件分析差异表达蛋白。结果显示,感染后40 d肝脏寄生的未成熟猪囊尾蚴和亚洲带绦虫囊尾蚴蛋白的双向电泳凝胶上分别有(236±12)和(231±14)个蛋白斑点,差异表达2倍以上的蛋白共10个,其中猪囊尾蚴表达上调的蛋白3个,下调的蛋白7个。     

Human Taeniasis and cysticercosis in Asia

CONTEXT: Human Taeniasis caused by the pork, Taenia solium, or beef, T saginata, tapeworm arises after eating pork or beef contaminated with metacestodes, the larval stage of these parasites. Taeniasis with T solium can lead to neurocysticercosis and threaten others by accidental ingestion of eggs released from asymptomatic Taeniasis patients. The 2003 World Health Assembly declared that T solium is of worldwide public-health importance, and that it is an eradicable parasitic disease worldwide. Adult taeniid tapeworms expelled from people in almost all Asian countries appeared to be T saginata (the so-called Asian Taenia), even though they ate pork. The organism is now named T asiatica, and has been found in Taiwan, Korea, China, Vietnam, and Indonesia. But it has been difficult to differentiate T saginata from beef and Asian Taenia from pork. STARTING POINT: Marshall Lightowlers and colleagues (Int J Parasitol 2003; 33: 1207-17) recently demonstrated that recombinant oncosphere vaccines against several taeniid cestodes, including T ovis, T saginata, T solium, and Echinococcus granulosus, are highly effective. Protection was almost 100%, in the laboratory and in the field. These researchers found several common features, including a predicted secretory signal sequence, and one or two copies of a fibronectin type III domain, each encoded by separate exons within the associated gene. WHERE NEXT? Molecular and immunological techniques, including vaccine research and development of animal models for differentiation of taeniid species in humans, have greatly advanced over the past decade. The clinical importance of infections by these taeniids, including T asiatica, in humans, and the potential for cysticercosis attributable to T asiatica in humans, needs further study.     

Demonstration of species-specific and cross-reactive components of Taenia solium metacestode antigens

Analysis of human serum reactivities to antigenic components of soluble Taenia solium metacestode proteins showed the predominant presence of determinants shared by T. solium, Echinococcus multilocularis and E. granulosus. Two polypeptides were demonstrated by SDS-PAGE and Western blot or enzyme-linked immunoelectrotransfer blot (EITB) assay to bind serum and CSF antibodies only from T. solium cysticercosis patients. These species-specific antigenic polypeptides focused between pH 4.6 and 3.9 after resolution by isoelectric focusing followed by EITB. The high species-specificity demonstrated by the present techniques offers the opportunity to confirm serologically an infection by T. solium metacestode.     

Molecular variation of Taenia solium in the world

Complete nucleotide sequences of the mitochondrial cytochrome b (Cytb) and cytochrome c oxidase subunit I (CO I) genes from various isolates of Taenia solium were examined. Eleven isolates were analyzed; two isolates from China, two isolates from Indonesia, one isolate each from India, Thailand, Mexico, Ecuador, Peru, Mozambique and Tanzania. In both genes, two isolates from Indonesia shared the same sequences. Similarly, the isolate from Mexico shared same sequences with that from Peru, and the isolate from Mozambique shared same sequences with that from Tanzania. Phylogenetic trees inferred from different mitochondrial genes yielded almost the same topology. Both the UPGMA and NJ-trees were also very similar. These trees indicate that T. solium may be diverged to 2 genetic groups; isolates from Asia form one group and isolates from Africa and Latin America belong to the other. It seems that T. solium prevalent in Africa and in Latin America shares the related origin and has recently been introduced to each area, perhaps with domestic pigs or human.     

猪带绦虫胰岛素受体TsIR-4810的鉴定及LBD区表达

目的 克隆鉴定猪带绦虫胰岛素受体TsIR-4810基因,并表达其LBD 区。方法 设计猪带绦虫胰岛素受体TsIR-4810特异性引物,并分段进行RT-PCR扩增。TsIR-4810的完整ORF序列经BLAST同源比对,SMART预测其结构域,SWISS-MODEL同源建模,并用PhyML构建系统发育树。将TsIR-4810的LBD区克隆至pET-30a中进行诱导表达,表达产物经SDS-PAGE和Western-blot鉴定。结果 获得的目的基因完整的ORF为4 920 bp,其编码蛋白的氨基酸序列与其他生物的胰岛素受体一样,具有相对保守的分泌信号肽、受体L1和L2结构域、FnⅢ结构域、跨膜区和受体酪氨酸激酶域。构建的LBD重组菌株诱导表达了63 ku的目的蛋白,与预期大小相符,且主要以包涵体形式存在。结论 TsIR-4810为猪带绦虫胰岛素受体基因,其LBD区的成功表达,将为开展基于胰岛素受体LBD区的新型疫苗和药物奠定基础。     

Application of synthetic peptides to the diagnosis of neurocysticercosis

We tested the possible diagnostic utility of five Taenia saginata oncosphere-derived synthetic peptides in T. solium neurocysticercosis (NC). The five peptides correspond to protein sequences with high antigenic indexes that were cloned from a T. saginata oncosphere cDNA library. The test samples consisted of cerebrospinal fluid (CSF) samples randomly collected from patients referred from Mexican and Brazilian neurological institutes. Indirect enzyme-linked immunosorbent assays (ELISA) were carried out with the peptides either unconjugated or coupled to carrier proteins, and were compared with results obtained using T. solium cyst fluid as a positive control. For active inflammatory NC, the higher sensibility (93%) and specificity (85%) was obtained with peptides HP6-2 and Ts45W-1, respectively, coupled to ovalbumin, in both Mexican and Brazilian patients. Examining the results of the individual peptide assays in combination, in some instances, improved the sensitivity to 100%.     

Vaccines for prevention of cysticercosis

Neurocysticercosis due to Taenia solium infection is an important cause of human morbidity and mortality. Despite the availability of effective anthelmintics, the disease remains prevalent in many parts of the world and there is a need for new and improved measures for control of the infection. An effective vaccine to prevent infection in pigs, the parasite's natural intermediate host, would be a valuable new option to assist with T. solium control. Several approaches are being used currently towards the development of a T. solium vaccine and these approaches are reviewed briefly, with emphasis on the use of recombinant oncosphere antigens. Highly effective vaccines have been developed against cysticercosis in sheep and cattle caused by Taenia ovis and Taenia saginata, respectively. This success has encouraged the adoption of a similar strategy for T. solium. The recent finding that one oncosphere antigen, TSOL18, can induce complete protection against T. solium infection in pigs, highlights the potential for development of a practical vaccine. A vision is proposed for the development of a safe, effective, inexpensive vaccine for pigs, which can be administered in an edible form. Through an international collaborative effort, research is progressing towards the realisation of such a vaccine and its use to reduce the global burden of neurocysticercosis.     

分子分类结合形态学方法对云南大理带绦虫的鉴定

目的 鉴定云南大理洱源(E1-E2)、鹤庆(H1-H2)、双廊(SL)、挖色(WS)带绦虫的种.方法 首先对大理分离株带绦虫成虫进行形态学鉴定,从成虫节片中抽提DNA,PCR扩增线粒体DNA细胞色素B(mtDNA-Cyth)的部分序列并测序;结合GenBank中已知猪带绦虫、牛带绦虫和亚洲带绦虫mtDNA-Cytb序列,经DNAMAN软件处理后构建系统发育树状图.结果大理带绦虫E1的形态和牛带绦虫相似,系统发育树显示大理分离株E1、E2、SL、WS带绦虫标本与亚洲带绦虫的遗传距离最接近,距牛带绦虫较远,与猪带绦虫则更远.大理分离株H1、H2带绦虫标本与猪带绦虫的遗传距离最近,距牛带绦虫和亚洲带绦虫则较远.结论 经形态学和分子生物学鉴定,云南大理分离株E1、E2、SL、WS带绦虫标本属于亚洲带绦虫,而H1、H2株带绦虫标本属于猪带绦虫.     

云南香格里拉的带绦虫rDNA-ITS1序列测定及分析

目的利用分子生物学技术鉴定产于云南香格里拉带绦虫的种类,以明确当地是否存在亚洲带绦虫。方法从云南香格里拉采集带绦虫标本株成虫节片,抽提DNA,PCR扩增rDNA-ITS1区段,克隆此片段后做序列测定;结合GenBank中已知的亚洲带绦虫、牛带绦虫、猪带绦虫rDNA-ITS1序列,经DNAMAN软件处理后计算遗传距离并构建系统发育树状图。结果香格里拉的带绦虫标本与GenBank中已知的亚洲带绦虫序列同源性为99%;与牛带绦虫同源性98%;与猪带绦虫同源性92%。系统发育树显示:香格里拉标本与亚洲带绦虫标本遗传距离最近,距牛带绦虫标本较远,与猪带绦虫则更远。结论云南香格里拉存在亚洲带绦虫。