转基因植物口服疫苗研究进展

利用转基因技术构建植物生物反应器,生产口服疫苗是目前新兴的研究领域。与其他疫苗生产方式相比,转基因植物口服疫苗生产技术具有高效、经济和简便等特点。根据转基因植物口服疫苗的特点,人和家畜家禽摄食方式的不同,应用转基因植物口服疫苗预防集约化饲养动物传染病的发生和流行,具有更为重要的意义。因此,转基因植物口服疫苗的研究热点逐渐由人的转基因植物口服疫苗向家畜和家禽的转基因植物口服疫苗的方向转移。文章就转基因植物口服疫苗的优点、人口服的转基因植物疫苗、家畜饲用的转基因植物疫苗及禽用的转基因植物口服疫苗做一综述。     

利用转基因植物生产畜禽口服疫苗的研究进展

利用转基因技术构建植物生物反应器,生产畜禽疫苗是新兴的研究领域。与其他疫苗生产方式相比,转基因植物畜禽疫苗生产技术具有高效、经济和简便等特点。应用转基因植物生产畜禽疫苗预防集约化饲养动物传染病的发生和流行,具有重要意义。就转基因植物口服疫苗的优缺点、畜禽饲用转基因植物疫苗研究进展进行综述。     

转基因植物疫苗研究进展

转基因植物疫苗作为一种口服疫苗,具有十分广阔的应用前景。本文从转基因植物疫苗的优点、转基因植物疫苗的应用前景、转基因植物疫苗的制作流程、转基因植物疫苗的作用机理、已获得的转基因植物疫苗等方面进行了论述。最后对转基因植物疫苗现存的问题进行了分析并提出了相应的解决方案,以便使转基因植物疫苗能更好的服务于畜牧生产。     

家禽新型疫苗研究有新成果——旅美学者吴红专博士访谈录

转基因植物口服疫苗优势突出。具有极大的潜力,尤其是针对畜禽饲用的口服疫苗,对于集约化养殖的传染性疫病的预防和控制将具有划时代的意义。不仅如此,随着畜禽口服转基因植物疫苗的长期使用,人们也会逐渐认识到转基因植物口服疫苗如同中草药一样,比起常规疫苗和其他基因工程疫苗是更为安全和有效。近日,本刊专访了对家禽转基因植物可食疫苗卓有研究的旅美学者吴红专博士,分享了有关家禽转基因植物可食疫苗、禽流感亚单位疫苗等方面的前沿科技和产业发展动态,以冀对我国家禽产业发展有所裨益。     

可食疫苗研究进展

对动物免疫成功与否，要看能否将易感群体减少到传染病可流行的阈值以下，因此免疫接种的广泛性是控制人盲疫病流行的重要因素之一。尽管医药科学已有飞速发展，但是由于疫苗的生产、配送等方面的限制，全球推广免疫接种仍然面临着巨大的困难。开发使用方便、廉价、高效疫苗，对控制全球各种疾病的爆发和流行有着深远的意义。目前，广泛研究的可食疫苗（Edible Vaccine）为解决这一难题提供了新的思路和方法。可食疫苗不仅有使用方便、安全的优点，而且一旦在转基因植物、动物或微生物中研究推广，可以立即为落后贫困地区人畜疫病防疫提供廉价可行的可食疫苗。本文主要综述目前广泛研究的几种可食疫苗的研究进展，主要包括：转基因植物可食疫苗、沙门氏菌携带的重组和DNA核酸可食疫苗、其他微生物携带或重组的可食疫苗，以及转基因动物生产的可食疫苗。     

转基因植物疫苗的开发及其在动物传染病防治中的应用

自首例植物疫苗投入市场来,许多植物物种经过遗传改造后用来表达抗原蛋白用于保护动物和人类健康。由于兽用疫苗比人用疫苗受到的限制比较少,所以吸引了大量的研究者、公司和投资商的关注,从而推动了转基因植物疫苗的迅速发展。植物疫苗可以直接口服免疫,避免了纯化过程,降低了生产成本,并逐渐走向成熟。本文就转抗原植物疫苗在发展中的问题、解决方案及其在动物传染病防治中的应用作一详细报道。     

口蹄疫转基因植物可饲疫苗研究进展

口蹄疫是由口蹄疫病毒引起的一种急性热性高度接触性传染病,给畜牧业造成极大的经济损失,疫苗是预防和控制该病的有效方法。近年来,转基因植物可饲疫苗由于其易于生产、成本低廉、使用方便和安全等诸多的优点成为口蹄疫新型疫苗的研究热点。文章综述了口蹄疫转基因植物可饲疫苗的研究现状,介绍了其原理和方法,分析了其优缺点和改进方法,并对其应用前景进行了展望。     

动物新型疫苗研究进展

近20年来．随着生物技术在兽医生物制品领域应用的不断深化和发展，疫苗制造技术和免疫学技术得到迅猛发展．产生了多种新型疫苗，包括基因重组亚单位疫苗．活载体基因工程疫苗、基因工程缺失疫苗和植物转基因工程疫苗等。此外，疫苗除应用于预防动物疫病外．新技术已将其扩展到治疗性疫苗、肿瘤疫苗和生理调控疫苗等。核酸疫苗、T细胞疫苗和树突状细胞疫苗彻底改变了疫苗多为蛋白．只能预防的经典概念，     

转基因植物生产亚单位疫苗的研究进展(下)

植物生产高附加值的医药制品是分子农业的重要研究领域,植物生产疫苗技术,开辟了疫苗生产的新纪元.与传统的动物反应器相比,植物反应器生产可食疫苗具有生产简便、成本低廉、易贮存和运输、使用方便、无需训练有素的医务人员等诸多优势,目前已经用于乙型和丙型肝炎、麻疹、霍乱等二十多种人和动物疫苗的开发研究,至少已有4种疫苗进入了临床实验阶段.本文就转基因植物生产亚单位疫苗的现状、作用机理、优越性、存在的问题和对策进行综述.     

植物基因工程疫苗的研究进展

植物基因工程疫苗是利用植物系统表达病原菌抗原蛋白一个或几个亚单位的疫苗，它没有病原菌完整的侵染能力，却可以使机体对特异的病毒或细菌产生免疫应答反应。由于转基因植物产生的疫苗对动物实施免疫只是简单地摄取含这种疫苗的植物组织或种子，所以这种疫苗不会被酶类所破坏，可通过机体肠道黏膜作用激发特异性免疫应答，使动物获得持久性疾病防御能力，且没有或很少出现病原体的过敏反应。     

两栖类动物肥大细胞生物学研究进展

文章对两栖类动物,特别是蛙科动物肥大细胞的个体发生、形态学、组织化学及其与外周神经和某些激素的关系及其生物学意义等进行了讨论。     

口蹄疫转基因植物疫苗研究进展

口蹄疫是国际社会广泛关注的严重动物传染病之一,其控制措施主要是疫苗免疫。传统疫苗在该病的防控中起了重要的作用,但是其弊端也不容忽视,研制新型的口蹄疫疫苗是今后的发展方向。近几年来,随着生物技术的发展,可饲疫苗由于其具备的诸多优点而成为国内外研究的热点,口蹄疫转基因植物疫苗的研究在国内外也已经开始,并取得了一定的成果,期望易感动物食用此转基因植物后产生免疫力,达到预防口蹄疫的目的。文章综述了国内外口蹄疫转基因植物疫苗研究的成果。     

猪轮状病毒的分子流行病学研究进展

轮状病毒是引起儿童和幼龄动物急性胃肠炎的主要病因之一,在世界范围内广泛存在,是一种重要的人兽共患病病原。猪轮状病毒是引起哺乳仔猪和断奶仔猪急性胃肠炎的主要病原之一,有复杂的病原流行病学特征和遗传多样性。目前尚无针对该病的有效治疗药物,疫苗接种仍是防控该病的主要措施。掌握猪轮状病毒的分子流行动态,可对诊断猪轮状病毒病和新型疫苗的研究提供科学依据。论文对猪轮状病毒的病原和分子流行病学调查结果进行了综述,旨在阐述不同地理区域中猪轮状病毒的流行特点,为进一步开展猪轮状病毒病原研究及后期疫苗和药物的研制提供参考。     

Detection of Human Rotavirus in Faeces from Diarrhoeic Calves in North-east Nigeria

Information on the epidemiology of rotavirus in any particular area is necessary for vaccine development against the disease caused by the virus. This study presents preliminary information on the prevalence of human rotavirus in diarrhoeic calves in North-east Nigeria. Faecal samples from 188 diarrhoeic calves in various farms in North-east Nigeria, obtained between November 1998 and February 1999, were analysed by ELISA for the presence of rotaviruses. A prevalence rate of 3.2% was recorded, with the virus being prevalent among calves aged 29–56 days (p<0.05). The implications of these findings are discussed with respect to the close association between the herdsmen and their animals and the sharing of a common source of drinking water in the predominantly livestock-producing communities of North-east Nigeria.     

A new polyvalent vaccine against enteral infections in newborn calves

The most frequent microbial causative agents of massive diarrheas in new-born calves kept on large cattle farms in the CSSR are rotaviruses, coronaviruses and enterotoxigenic strains of E. coli, manifesting themselves as complicated virus-bacterial infections. An inactivated polyvalent adjuvant vaccine has been developed for the prevention and specific prophylaxis of these enteral infections; the vaccine contains bovine rotavirus, bovine coronavirus and three enterotoxigenic serotypes of E. coli with protective antigen K 99. The rotavirus and coronavirus are propagated on the stable cellular line MDBK and inactivated with 0.2% formalin, the Escherichia strains are submersed in the MINCA culture medium during their cultivation and inactivated with 0.5% formalin. The vaccine was prepared as a blend of the same amounts of rotavirus and coronavirus and of such an amount of bacterin so that 1 ml of the vaccine will contain 10(9) bacteria. One part of oil adjuvant was added to five parts of the virus-bacterial blend and the blend was homogenized in the Ultraturax apparatus. The vaccine is to be used for immunization of pregnant cows and heifers; in these animals it induces the production of specific antibodies to all antigens contained in the vaccine. Its immunogenic effects were checked in 32 calves and 38 cows in the herds with the occurrence of diarrheas caused by both enteropathogenic viruses and enterotoxigenic escherichia. It was demonstrated that the inactivation did not influence in either of the viruses the process of inducing the production of specific antibodies, and the antibody response of the calves and heifers after application of 2 ml of complete inactivated vaccine was equally strong as after application of live vaccine containing only rotavirus and coronavirus. The level of the rotavirus antibodies increased on the average 30 times and 200 times, coronavirus antibodies twice and four times. The antibody response to coronavirus was negatively influenced by the relatively high levels of antibodies before vaccination. The antibody response to antigen K 99 was expressive in all cases.     

仔猪轮状病毒性腹泻的研究进展

仔猪轮状病毒性腹泻是由猪轮状病毒引起的急性肠道传染病,是危害养猪业的主要疾病之一。猪轮状病毒是一种条件性病原,一般情况下呈隐性感染,当环境因素发生变化、免疫力下降时可暴发。目前尚无有效治疗药物,预防该病的有效方法是加强饲养管理和有效疫苗接种。研制新一代高效、廉价疫苗是重要的研究方向。掌握仔猪轮状病毒性腹泻的动态变化和影响因素,可为其诊断以及疫苗的研制提供科学依据,并为该病发展趋势的科学预测提供数据和信息支持。文章综述了引起仔猪腹泻的猪轮状病毒的分群和分型、培养特性、流行病学、预防治疗及疫苗研制的现状。     

Immune response of pregnant heifers and cows to bovine rotavirus inoculation and passive protection to rotavirus infection in newborn calves fed colostral antibodies or colostral lymphocytes

The efficacy of an adjuvanted bovine rotavirus vaccine in pregnant cattle (15 heifers and 2 cows) was studied. Each of 4 animals was inoculated IM at 8, 5, and 2 weeks before parturition with a water-in-oil emulsion containing live purified bovine rotavirus, mineral oil, and a mannide oleate compound. Four other animals were treated identically, except that muramyl dipeptide was added to the virus preparation. Five additional animals were inoculated orally at the same time intervals with adjuvant-free viral suspension, and 4 other pregnant animals inoculated only with buffer served as uninoculated controls. Kinetic studies of the specific immune responses were determined by quantification of the rotavirus-neutralizing antibodies and by a rotavirus lymphocyte stimulation test in vitro. Results showed that only the emulsions induced marked enhancement of rotavirus antibody titers in the serum, colostrum, and milk of inoculated cows. Colostral and milk lymphocytes isolated from these cows had a positive in vitro proliferative response to rotavirus stimulation, which lasted at least 21 days after parturition. The values of the stimulation index obtained with the colostral/milk lymphocytes were higher than those of the blood lymphocytes, reflecting increased lymphocyte activity in the colostrum/milk. However, addition of muramyl dipeptide to the emulsion preparation did not exert any potentiating effect on the immune response to rotavirus. Calves fed for the first 5 days after birth with a rotavirus-immune cell-free colostrum supplement were protected from a rotavirus challenge exposure on the third day after birth. Virus was not detectable in their feces.(ABSTRACT TRUNCATED AT 250 WORDS)     

轮状病毒分子生物学研究进展

轮状病毒(rotavirus,RV)是引起婴幼儿和多种幼龄动物非细菌性腹泻病的主要病原之一,全世界每年因该病所引起人和动物死亡数量众多,并造成了巨大的经济损失。因此,世界卫生组织呼吁将RV疫苗的研制列为最优先发展的疫苗项目之一。对RV的分子生物学研究进展进行了综述,旨在为更好地开展轮状病毒相关基因的实验室研究提供基础。     

Further studies on passive immunization of newborn calves against rotaviral infection

An inactivated rotavirus vaccine was prepared with an adjuvant which gives a water-in-oil emulsion. The vaccine when injected into cows in their last month of pregnancy, proved to be as effective as the traditional vaccine, prepared with the Freud's incomplete adjuvant, in enhancing the lactogenic immunity. Thus, feeding experimentally infected calves with colostrum and first milk from vaccinated cows prevented diarrhea and reduced significantly rotavirus shedding. Because of its low grade viscosity the water-in-oil emulsifier facilitates inoculation of the vaccine and is therefore recommended as an adjuvant in the preparation of inactivated rotavirus vaccine.