弓形虫的基因型及其主要效应分子的致病机制  

Genotypes and Main Effectors of Toxoplasma gondii and Their Pathogenic Mechanisms

作　　者：沈继龙[1] 王林[2] 

机构地区：[1]安徽医科大学病原生物学教研室,安徽病原生物学省级实验室,安徽省人兽共患病重点实验室,合肥230032 [2]安徽中医药大学第一附属医院检验中心,合肥230031

出　　处：《中国寄生虫学与寄生虫病杂志》2015年第6期429-435,共7页Chinese Journal of Parasitology and Parasitic Diseases

基　　金：国家重点基础研究发展计划(973计划)(No.2010CB530001);国家自然科学基金(No.81471983)~~

摘　　要：弓形虫(Toxoplasma gondii)是一种广泛寄生于人和温血动物有核细胞内的顶复门原虫(Apicomplexan),具有复杂的生活史和致病机制。Toxoplasma属下仅此一个虫种,但对其种群遗传结构的研究表明,世界各地的弓形虫存在着丰富的遗传多样性。采用PCR-限制性片段长度多态性分析(RFLP)或微卫星标记分型,已从野生动物、家养禽畜和人体分离虫株中发现了232个基因型。其中,北美的弓形虫基因型以typeⅡ、typeⅢ和type12(主要见于野生动物)为主;欧洲以typeⅡ、typeⅢ和typeⅠ为主;非洲以typeⅡ和typeⅢ为主。以上称为原型克隆谱系。但南美的弓形虫表现出丰富的遗传多样性,包括BrⅠ、BrⅡ、BrⅢ和BrⅣ型等。近年研究发现,我国流行的弓形虫优势基因型为Chinese 1型(Toxo DB#9)。该型虫株兼具有原型谱系虫株关键效应分子的多态性。本文综述了世界各地包括我国在内的基因型、宿主免疫应答及其致病特点,为深入研究基因型/效应分子相关的致病机制,以及弓形虫的生物学和流行病学研究提供借鉴。Toxoplasma gondii is an intracellular Apicomplexan parasite that infects a wide range of warm blooded animals, including human, and has complex life cycle and pathogenic mechanisms. Although T. gondii is the only species recognized in the Toxoplasma genus, research on population genetic structure has shown its geographic genetic diversity. So far 232 genotypes have been identified by multilocus polymerase chain reaction-restriction frag- ment length polymorphism or microsatellite genotyping from both animals and human. T. gondii strains in North America typically possess types 2, 3 and 12 （found mainly in wild animals） clonal lineages, while types 2, 3, and 1 are common in Europe, and types 2 and 3 are common in Africa. These findings suggest a strongly clonal popu- lation structure in these regions. However, strains in South America are genetically more diverse, predominated by types Br Ⅰ, Br Ⅱ, BrⅢ, and BrlV. Recent research has shown that the Chinese 1 （ToxoDB#9） genotype is domi- nantly circulating in the mainland of China, and shares the polymorphic ROP16Ⅰ/Ⅲ with types 1 and 3, and GRA15, with type 2. In this review, we summarized geographically the genotypes, host immune responses, and the pathogenic mechanisms of T. gondii strains, to provide basis for further research on genotype/effector-related pathogenic mecha- nism as well as biological and epidemiological studies of T. gondii.

关 键 词：弓形虫 基因型 PCR-限制性片段长度多态性分析 致病机制 免疫应答 

分 类 号：R382.5[医药卫生—医学寄生虫学]