猪带绦虫六钩蚴45W-4B重组蛋白的免疫原性研究

目的观察猪带绦虫六钩蚴45W-4B抗原对仔猪的免疫保护作用。方法用IPTG诱导表达融合蛋白GST-45W-4B。用GST柱进行纯化，以Montanide ISA 206为佐剂制成疫苗免疫仔猪。间接ELISA检测仔猪血清抗45W-4B IgG抗体水平，MTT法进行外周血淋巴细胞殖试验。免疫1个月后全部实验组经口攻击感染25000彬头猪带绦虫虫卵，攻虫3个月后剖检，计算减虫率及保护率。结果免疫组注射疫苗的第2周起，抗体为阳性，45W-4B组持续升高至第8周，淋巴细胞增殖明显高于未免疫感染组。用该抗原制备的疫苗获得了95％的减虫率和33％的保护率。结论该抗原对猪囊尾蚴病具有很好的免疫保护作用。     

猪带绦虫TSOL18特异性单克隆抗体的制备及其体外杀虫作用的研究

本研究目的在于制备抗猪带绦虫TSOL18单克隆抗体,并分析单抗对六钩蚴的杀伤作用。采用SephadexG-100纯化在毕赤酵母中表达的猪带绦虫六钩蚴TSOL18蛋白;纯化的蛋白免疫BALB/c小鼠,运用杂交瘤技术建立能分泌抗TSOL18单克隆抗体的细胞株;通过ELISA叠加试验进行mAb的抗原表位分析;采用间接ELISA法测定TSOL18单克隆抗体特异性及腹水效价;采用抗TSOL18单克隆抗体对激活的猪带绦虫六钩蚴进行体外六钩蚴杀伤试验,观察单抗对猪带绦虫六钩蚴活力的影响。结果成功获得12株稳定分泌抗TSOL18单克隆抗体的杂交瘤细胞株,识别2个不同抗原表位,不同抗原表位的2株单克隆抗体腹水效价分别为1×102、1×106。抗体体外六钩蚴杀伤试验结果证明,在有补体的情况下,多抗和单抗作用6 d后,六钩蚴结构模糊,边缘不清晰。表明单抗对六钩蚴有一定的杀伤作用。     

猪囊尾蚴病免疫原的分子生物学研究进展

猪带绦虫有成虫、虫卵、六钩蚴、囊尾蚴不同形式的发育阶段和寄生状态，不同的虫体形式以独特的组织结构和生命活动规律满足其寄生在相应宿主体内的需要。研究发现，六钩蚴与囊尾蚴在虫体组成成分、生化指标以及代谢(分泌)产物等方面都有差异。SDS-PAGE和免疫印迹研究表明，六钩蚴的抗原成分非常复杂，不仅有共同抗原、阶段发育特异性抗原，而且在入侵宿主定植在肌肉组织后，表     

猪囊虫病基因工程疫苗的研制

从猪带绦虫六钩蚴ｃＤＮＡ文库中筛选目的基因并进行克隆表达,重组抗原用血清学方法和猪体免疫进行鉴定。钭具有免疫保护作用的重组抗原纯化,与免疫刺激复合物疫苗佐剂混合,制备成猪囊虫病基因工程疫苗,免疫仔猪并攻虫。该疫苗安全,无毒副作用,免疫猪减虫率９２．２％,完全保护率５５．５％,且免疫组发现的囊虫多数已死亡。     

囊虫匀浆诱导猪对囊虫病的保护性免疫

绦虫感染在经济、公共卫生上的重要性,促进了寄生虫免疫学的广泛研究。六钩蚴体外短期培养所产生的代谢物,免疫牛、羊等带科绦虫病国外已进入实用阶段。但猪囊尾蚴匀浆直接免疫猪囊虫病尚未见报道。本试验以囊尾蚴(A)、囊液(B)、六钩蚴(C)为免疫原,处理各试验动物组,结合     

猪带绦虫不同发育阶段的cDNA合成及含量测定

本文以猪带绦虫成熟虫卵、孵化激活的六钩蚴以及人工感染的囊尾蚴为原始材料，采用Promega试剂盒法分别分离提取总RNA和mRNA，反转录合成cDNA，并用a-^32P CTP掺入法放射测定其含量。实验表明：合成的猪带绦虫虫卵、六钩蚴和囊尾蚴的cDNA含量高，均可达2500ng，片段大小在300bp以上，可满足构建不同发育阶段cDNA基因文库的需要。     

用猪带绦虫培养抗原对猪的免疫

用体外培养六钩蚴获得的分泌排泄抗原,免疫8头实验室繁殖的15日龄猪,来防治猪带绦虫感染,另8头未免疫猪作对照。免疫后30天,将两组猪都口服15000个虫卵攻击。12周后将全部猪剖杀,进行详细检查。与对照猪相比,免疫猪的感染率比对照猪降低了94.9%,免疫猪的囊虫数量的减少是保护力     

猪带绦虫培养抗原对猪的免疫试验

本文评估了感染性猪带绦虫的排泄一分泌同种抗原免疫猪后的保护效果。试验表明,免疫猪在攻击感染后,其肌肉中囊尾蚴数量减少。     

人工感染的亚洲带绦虫六钩蚴在幼猪体内的分布和致病观察

亚洲带绦虫是以猪为中间宿主的人体带绦虫,为了研究其幼虫的肝趋向性和组织选择性,试验分别用亚洲带绦虫虫卵灌胃和酶法孵化出六钩蚴后以静脉注射方式感染幼猪,35d后剖检,观察六钩蚴在猪体内的分布、发育和引起病变的特征。结果表明:两种途径入侵家猪的亚洲带绦虫六钩蚴都仅在肝脏发育成囊尾蚴;经静脉感染的幼猪肝脏、肺脏、肾脏、肌肉和皮下组织可检出以嗜酸性肉芽肿为主要特征的病变;经灌胃感染的幼猪则仅见肝脏出现病变,其他组织器官未见明显病变。     

猪囊尾蚴病病原入侵与免疫机理以及免疫预防研究进展

猪囊尾蚴病是危害严重的人畜共患寄生虫病,其病原是复杂的真核生物,有猪带绦虫成虫、六钩蚴、囊尾蚴等多个发育阶段,在人猪之间循环感染寄生发育。目前国内外已在病原和宿主个体、细胞和分子水平上对猪囊尾蚴入侵与免疫、免疫与免疫逃避以及免疫预防等方面进行了大量的研究,初步明确了虫体的组成成分与结构形态以及发育形式,与病原入侵和免疫的关系,为免疫预防控制,特别是分子免疫预防奠定了坚实的基础。但要完全控制和消灭该病,要走的路还很长。     

The highly antigenic 53/25 kDa Taenia solium protein fraction with cathepsin-L like activity is present in the oncosphere/cysticercus and induces non-protective IgG antibodies in pigs

Cathepsin L-like proteases are secreted by several parasites including Taenia solium. The mechanism used by T. solium oncospheres to degrade and penetrate the intestine and infect the host is incompletely understood. It is assumed that intestinal degradation is driven by the proteolytic activity of enzymes secreted by the oncosphere. Blocking the proteolytic activity by an antibody response would prevent the oncosphere penetration and further infection. Serine and cysteine proteases including chymotrypsin, trypsin, elastase, and cathepsin L, are secreted by T. solium and Taenia saginata oncospheres when cultured in vitro, being potential vaccine candidates. However, the purification of a sufficient quantity of proteases secreted by oncospheres to conduct a vaccine trial is costly and lengthy. A 53/25 kDa cathepsin L-like fraction partially purified from T. solium cyst fluid was described previously as an important antigen for immunodiagnostics. In this study we found that this antigen is present in the T. solium oncosphere and is also secreted by the cysticercus. This protein fraction was tested for its ability to protect pigs against an oral challenge with T. solium oncospheres in a vaccine trial. IgG antibodies against the 53/25 kDa cathepsin L-like protein fraction were elicited in the vaccinated animals but did not confer protection.     

Taenia solium oncosphere antigens induce immunity in pigs against experimental cysticercosis

Immunity to Taenia solium infection was investigated using an experimental intramuscular oncosphere infection assay (IMOA) model in pigs. Three naturally infected pigs with cysticercosis were treated with oxfendazole (OFZ), a drug demonstrated to kill cysts in porcine muscle. These animals were then challenged with oncospheres but did not develop any cysts while three uninfected pigs that were similarly challenged, did develop intramuscular cysts. In another study, two groups of three pigs each were immunized with crude T. solium oncosphere and metacestode antigens, respectively, and tested with the IMOA. Immunization with crude oncosphere antigens (OAs) induced 100% protection, while metacestode antigens provided only partial protection. Immunoblots showed that pigs with complete immune protection to oncosphere intramuscular challenge had antibodies to two OAs at 31.3 and 22.5 kDa, respectively. Antibody to these two antigens was absent in pigs immunized with metacestodes or in uninfected control pigs. This study demonstrated the presence of two antigens that are unique to the oncosphere. Although, antibody to these two antigens is consistently present in pigs that are protected from an oncosphere intramuscular challenge their role in preventing infection by T. solium larval cysts is still hypothetical.     

Isolation of a 14 kDa antigen from Taenia solium cyst fluid by HPLC and its evaluation in enzyme linked immunosorbent assay for diagnosis of porcine cysticercosis

A fraction with a major band of 14kDa was obtained from crude cyst fluid of Taenia solium cysticerci by 2-step chromatography. A first fraction isolated by gel filtration (Sephacryl S-300 high resolution) was purified using an anion exchange column (Mono Q HR 5/5) on high performance liquid chromatography. Evaluation of the analytic sensitivity of this fraction (F3) was carried out in an antibody enzyme linked immunosorbent assay (Ab-ELISA-F3) using serum samples from pigs experimentally infected with different doses of T. solium eggs. The cross-reactivity of F3 was evaluated with serum samples from pigs that were naturally or experimentally infected with Taenia hydatigena, Taenia saginata asiatica, Fasciola hepatica, Trichinella spiralis, Metastrongylus apri, Trypanosoma congolense and Sarcoptes scabiei, and with serum samples of rabbits hyper-immunised with metacestode cyst fluid of T. hydatigena and T. solium. Antibody titres of lightly or heavily infected pigs differed in their kinetics. However, the increase in F3-specific antibodies could not be related to the infection level. Analysis of the specificity of the F3 showed that serum samples of pigs infected with other parasites did not recognise this antigen. Cross-reaction with T. hydatigena occurred in ELISA using cyst fluid as antigen, but the F3 antigen fraction was not recognized by rabbit hyper-immune serum samples to T. hydatigena. Evaluation of the diagnostic sensitivity and specificity of the Ab-ELISA-F3 was done by a non-parametric receiver operating characteristic (ROC) analysis using 66 serum samples from Zambian village pigs. The total number of cysticerci of these pigs was determined by dissection (28 pigs harboured T. solium cysticerci and 38 were negative at dissection). In addition, 58 serum samples from Cameroonian pigs (28 pigs from cysticercosis-free farms and 30 pigs with cysticerci at tongue inspection) were used in a separate ROC analysis. The results from the ROC analysis yielded a low diagnostic value (area under ROC curve=0.48) with the sera from the Zambian pigs while a relatively high diagnostic value was obtained with the sera from Cameroonian pigs (area under ROC curve=0.78). The main factor contributing to a low diagnostic value based on the Zambian serum samples seemed to be the false-positive reactions that were likely caused by the occurrence of transient antibodies in the non-infected animals.     

猪带绦虫不同阶段及羊囊尾蚴蛋白质分析

利用浓度梯度SDS－聚丙烯酰胺凝胶电泳对猪囊尾蚴的囊液和虫体，猪带绦虫成虫的头颈节、成节、孕节，猪带绦虫的虫卵以及羊囊尾蚴的蛋白成分进行了对比分析。结果发现：囊液、虫体、头颈节、成虫、孕节、虫卵、羊囊尾蚴分别有35条（15．0－150．4kd）、44条（15．0－133．7kd)、22条（13．3－163．9kd)、19条（13．3－90．1kd)、19条（13．3－90．1kd)、30条（13．3－99．4）和38条（15．0－133．4kd)蛋白带；其中15．0kd和35．5kd两条共同抗原蛋白带，在猪带绦虫各阶段和羊囊尾蚴中含量最大的蛋白带同时也是阶段性的共同抗原蛋白带。这些结果为下一步的保护性抗原筛选奠定了基础。     

猪囊尾蚴基质金属蛋白酶-9在猪肌肉和脑组织的表达分布

应用免疫组化分析猪囊尾蚴基质金属蛋白酶-9(MMP-9)的表达.用猪带绦虫卵1 mL(8万个/mL)灌胃20 d龄健康乳猪6头,于感染后40、80、120 d分别宰杀2头猪并取含囊尾蚴的肌肉及脑组织制作4μm厚石蜡切片,采用Envision二步法,观察不同时期寄生在肌肉及脑组织的猪囊尾蚴基质金属蛋白酶-9的表达.结果显...     

Cross-reactions between crude antigens of larval Taenia solium (Cysticercus cellulosae) and other helminths of pigs

A crude antigen extract of larval Taenia solium was shown by immunodiffusion (ID) and immunoelectrophoresis (IEP) to cross-react with rabbit antisera against pig serum proteins and larval T. hydatigena, and by enzyme-linked immunosorbent assay (ELISA) with antisera against pig serum proteins, Fasciolopsis buski, larval T. hydatigena, hydatid cyst, Hymenolepis diminuta and Dipylidium caninum. Immunoblotting demonstrated that the crude antigens extract contained epitopes of pig serum proteins of 48 and 66 kDa. The crude extract also contained a subunit of antigen B (95 kDa) which was also found in T. hydatigena and H. diminuta. Immunoperoxidase and indirect immunofluorescence studies showed that cross-reacting antigens were distributed mainly on the tegument of T. solium.     

Evaluation of tongue inspection and serology for diagnosis of Taenia solium cysticercosis in swine: usefulness of ELISA using purified glycoproteins and recombinant antigen

Evaluation of serology using glycoproteins (GPs) purified by preparative isoelectric focusing (pH 8.8) and recombinant chimeric antigen (RecTs) of Taenia solium was carried out using (1) blood samples on filter papers from pigs infected with different doses of eggs of T. solium in Mexico, (2) serum samples from pigs found infected naturally in Vietnam and Ecuador and (3) serum samples from pigs suspected to be infected with T. solium by tongue inspection in Tanzania. Antibody responses (IgG) were detectable in experimentally infected pigs confirmed harbouring 16 or more cysts at necropsy from 30 days after egg inoculation. One of three pigs naturally infected and harbouring 2.5 cysts/kg muscle and most of pigs harbouring=5.0 cysts/kg were also seropositive by ELISA. Although pigs may be infected with other taeniid species such as Taenia hydatigena, pigs harbouring this parasite were negative in ELISA. Approximately, 76 and 78% of sera from pigs having nodule(s) in the tongue (positive tongue inspection) were serologically positive by both ELISA and immunoblot, respectively. Furthermore, approximately 34 and 18% of sera from pigs having no nodules in the tongue (negative tongue inspection) were also seropositive by ELISA and immunoblot, respectively. ELISA using the two antigens was more sensitive than immunoblot and reliable for differentiation of pigs infected with cysticerci of T. solium from those either uninfected or infected with other taeniid species. Pigs without nodule by tongue inspection should be checked serologically in endemic areas.     

Effect of Paecilomyces lilacinus on the viability of oncospheres of Taenia hydatigena

Paecilomyces lilacinus (Thom) Samson is a saprophytic hyphomycete from the soil with biological activity on helminth eggs. We evaluated the influence in vitro of P. lilacinus on the viability of the oncospheres from Taenia hydatigena, a parasite cestode of dogs and sheep. The eggs were exposed to the fungus strain in sterile distilled water and observed by light microscopy at days 4, 7 and 14 post-inoculation, and the viability was evaluated. The viability found in the exposed P. lilacinus oncospheres was significantly different in all observations. P. lilacinus exercised a negative biological activity on T. hydatigena eggs in vitro.     

犬泡状带绦虫潜在前期研究与PCR鉴定

为查明猪细颈囊尾蚴在犬体内发育为成虫后节片的最早排出时间（潜在前期）,将新鲜的猪细颈囊尾蚴经口感染6只无绦虫犬后,采用反复水洗沉淀法检测感染犬粪中排出的第1个绦虫节片,并用特异PCR方法鉴定其种属。结果显示,6只感染犬的潜在前期分别为60、63、65、69、72、73 d。同时,特异性PCR结果显示其序列与Genbank收录的泡状带绦虫序列的相似性为99%,确认犬排出的节片为泡状带绦虫。本研究为建立泡状带绦虫在宿主体内的发育模型提供了一定的基础资料。