DEVELOPMENT OF MALARIA MULTIPLE ANTIGEN PEPTIDE(MAP) VACCINE

疟疾感染在流行地区造成约300万人死亡，全世界每年有20多亿人面临感染这种疾病的风险。该病的病原体是疟原虫属的寄生虫。随着对这种寄生虫耐药性的出现，有必要开发疟疾疫苗。其他人正在使用几种方法来开发安全有效的疫苗。我们选择开发一种多抗原肽(MAPS)疫苗，因为它避开了使用减毒活寄生虫、热灭活寄生虫或重组抗原时遇到的几个限制。例如，外来病原体的存在，以及难以产生足够的寄生虫，往往与活的或热灭活的寄生虫有关。同样，重组抗原的生产需要劳动密集型的纯化和鉴定过程。我们已经成功地合成了三个不同的图谱，其中包含了疟疾寄生虫生活史中表达的不同抗原的表位。这些表位包括肝期特异性蛋白(LSA-1)的T和B细胞表位、血期裂殖子表面抗原(MSP-1)和子孢子特异性环子孢子蛋白(CSP)。这是第一次合成了这种性质的地图，这些地图是完全可以表征的。目前，这些图谱正在两个不同品系的小鼠身上进行免疫学评估。对免疫反应类型的研究也在进行中。

Malaria infection causes ~ 3 million deaths in endemic areas and over two billion people world-wide per year are at risk of getting the disease. The causative agent of the disease is the parasite of genus Plasmodium. With emergence of drug resistance to this parasite, there is a need for developing malaria vaccine. Several approaches are being used by others to develope a safe and efficacious vaccine. We have choosen to develope a mutiple antigen peptide (MAPs)vaccine because it circumvents several limmitations which one encounters while using attenuated live parasites,heat killed parasites or recombinat antigens. For example,presence of adventitious agents, and difficulty of generating enough parasites is often associated with live or heat killed parasites. Simlarly, production of recombinant antigens requires labor intensive process of purification and characterization. We have sucessfully synthesized three different MAPs containing epitopes from different antigens expressed during life cycle of malaria parasite. These include T- and B-cell epitopes from liver stage specific protein (LSA-1), blood stage merozoite surface antigen (MSP-1), and sporozoite specific circumsporozoite protein (CSP). It is for the first time that MAPs of this nature have been synthesized which are fully characterizable. Currently, these MAPs are being evaluated immunologically in two different strains of mice. Studies are also underway to characterize the type of immunological response.