Toxoplasma gondii: cyst wall

描述（由申请人提供）：刚地弓形虫是一种普遍存在于哺乳动物体内的寄生虫，属于顶端复合体。这种原生动物对中枢神经系统的偏爱导致坏死性脑炎构成了HIV感染患者的主要表现。由于它可以通过食物或水传播，弓形虫被列为美国国立卫生研究院优先考虑的B类病原体。在最初的感染中，快速增殖的弓形虫速殖子阶段分化为缓慢复制的潜伏在组织内的慢殖子阶段

DESCRIPTION (provided by applicant): Toxoplasma gondii, a member of the Apicomplexa, is a ubiquitous parasite of mammals. The predilection of this protozoan for the central nervous system causing necrotizing encephalitis constitutes its major presentation in patients with HIV infection. Because it can be transmitted by food or water T. gondii is classified as a category B NIH priority pathogen. During initial infection the rapidly proliferating tachyzoite stage of T. gondii differentiates into the slowly replicating bradyzoite stage that remain latent within tissue cysts for the life of the host; however reactivation of this latent infection can result in disease such chorioretintiis or encephalitis. Several lines of evidence suggest that bradyzoite differentiation is stress mediated and that the cyst wall (a modified parasitophorous vacuole membrane) contains many stage specific proteins and glycoproteins. In the present proposal, studies will be focused on the characterization of the components of the cyst wall. The components of the cyst wall will be characterized using a combination of proteomic, immunologic and genetic approaches taking advantage of techniques we have developed for purification of the T. gondii cyst wall. We have already identified several cyst wall specific proteins that have mucin type domains. Other investigators have previously noted that o-glycosylation occurs in T. gondii and is probably involved in differentiation. We will, therefore, also examine the role of o-glycosylation and mucin type linkages in the development of the cyst wall using biochemical and genetic approaches. Overall these studies will both elucidate the composition of the cyst wall and the glycoproteome of T. gondii providing reagents and insights that should prove useful in understanding the biology and organization of this critical structure. Understanding this structure is important for the development of new strategies to eliminate latent infection and prevent reactivation toxoplasmosis.