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【drug-news】科学家研制一种新型的黑热病疫苗
Posted: July 21, 2006
Scientists Prepare An Innovative Vaccine Against Leishmaniasis
Universitat Autonoma De Barcelona researchers working in collaboration with the INIA (National Institute of Agricultural and Food Research and Technology) and Germans Trias i Pujol Hospital in Badalona, near Barcelona, are developing the first vaccine against leishmaniasis produced using insect larvae. The new vaccine is based on introducing specific genes and proteins from the protozoan Leishmania infantum into the patient. Although it is currently in the preliminary phase, scientists believe it could be much more effective than conventional vaccines.
Leishmaniasis is one of the biggest global health problems. In our part of the world, it is produced by the protozoan Leishmania infantum, and dogs are the main reservoir. The disease is spread through the bites of the phlebotomy, an insect similar to the mosquito. Clinical manifestations go from light skin lesions to visceral complications and even death. The disease affects more than 12 million people in the world, and 250 million more are at risk. Current treatments are not satisfactory, and although an effective vaccine would be the best way to confront the disease, conventional vaccines have failed.
UAB researchers working in collaboration with the INIA and Germans Trias i Pujol Hospital are working on the development of an unconventional vaccine that could be more effective in treating the disease. In an effort to make the vaccine as specific as possible, the researchers are conducting epidemiological tests on dogs and humans to find out whether the degree of the illness and the differences between regions, species (dog or humans) and infected individual persons are related to the presence of different antibodies against the infectious agent, the protozoan Leishmania infantum.
To create the vaccine and the reagents used in the epidemiological studies, the scientists have isolated the protozoan gene and inserted it into a virus that affects insects (baculovirus) and have infected the larvae of a small worm (Trichoplusia ni) with them. These larvae act as bioreactors and produce large quantities - and at a much lower cost than with conventional reactors involving microorganisms - of the proteins that are codified by these genes and are responsible for the production of antibodies in those affected. Each person would be administered a DNA vaccine with the genes that codify for the proteins of the protozoan that generates most antibodies in the geographical region. Later, the person would be vaccinated again, but this time directly with the proteins associated with this genes (produced cheaply in insect larvae). The aim is to increase effectiveness. The vaccines could be used as prevention or therapeutically.
"Selectivity for each individual and the combination of the vaccination with DNA and protein will probably make this new vaccine much more effective than current ones. Furthermore, the method of producing them in insect larvae would considerably reduce the costs," explains Jordi Alberola, the main researcher for the project.
Collaborating in the research, directed by Jordi Alberola of the UAB Department of Pharmacology, Therapeutic, and Toxicology and member of the UAB Drug Analysis Service, are the bioreactors research group led by Dr José Ángel Martínez Escribano of the National Institute of Research and Agri-Food Technology, and the group les by Dr Guillem Sirera of Germans Trias i Pujol Hospital in Badalona.
Jordi Alberola. (Image courtesy of Universitat Autonoma De Barcelona)
screen.width-333)this.width=screen.width-333" width=300 height=334 title="Click to view full 060721095010.jpg (300 X 334)" border=0 align=absmiddle> 认领此篇 消息来源：巴塞罗那自治大学
录入时间：2006-7-21
科学家研制一种新型的黑热病疫苗
巴塞罗那自治大学研究人员与INIA（国家农业与食品研究机构）和Germans Trias i Pujol医院（巴塞罗那附近的巴达洛纳）合作，利用利什曼昆虫幼虫研制了第一支黑热病疫苗。这种新疫苗的基础是引入了由利什曼幼虫得到的特异性基因和蛋白到病人体内。尽管前期的效果还很一般，但是科学家们坚信这将比传统的疫苗有效得多。
黑热病是最大的全球类健康问题之一。在这里，黑热病是由利什曼幼虫造成的，以狗为主要宿主。它通过蚊虫叮咬传播。临床表现从轻微的皮肤病损到内脏并发症甚至死亡。现在黑热病侵袭了世界上超过一千二百万人，而且有二十五千万人处于高患病风险。当前的治疗方法不尽人意，尽管对付黑热病的最好的方法就是有效的疫苗，但是传统的疫苗效果并不好。
巴塞罗那自治大学研究人员与INIA（国家农业与食品研究机构）和Germans Trias i Pujol医院合作，致力于研制一种非传统疫苗以更有效的预防这种疾病。为了使疫苗的特异性更强，研究人员在狗和人上作了流行病学测试，以检测是否疾病等级，地域，种属（狗或人）以及被感染个体的不同会关系到针对感染源（原生动物利什曼幼虫）的不同抗体的产生。为了制造供流行病研究的疫苗和制剂，科学家们分离了这种幼虫的基因然后把它们注射进可以感染昆虫的病毒内（杆状病毒），并且用它们感染小型蠕虫（粉纹夜蛾）的幼虫。这些幼虫作为生物反应器生产大量由这些基因编码可以刺激抗体产生的蛋白质，这比传统的微生物反应廉价很多。在一定地域内的每个人都要给予这种DNA疫苗，它可以编码可以诱导最多抗体产生的幼虫蛋白。之后，每个人还要再次接种，但是这次是直接给予该基因编码的蛋白（通过昆虫幼虫廉价生产的），用来增加功效。这种疫苗可以用来预防或治疗。
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作者:admin@医学,生命科学 2011-03-27 17:11
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