Reexamining Chronic Toxoplasma gondii Infection: Surprising Activity for a "Dormant" Parasite.
Reexamining Chronic Toxoplasma gondii Infection: Surprising Activity for a "Dormant" Parasite.
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DOI：
10.1007/s40588-016-0045-3
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发表时间：
2016-12
影响因子：
5.2
通讯作者：
Patwardhan A
中科院分区：
文献类型：
--
作者：
Sinai AP;Watts EA;Dhara A;Murphy RD;Gentry MS;Patwardhan A
尽管超过三分之一的世界人口被慢性感染弓形虫，很少有人知道这个大部分无症状的感染阶段。该阶段在体内由组织包囊内的缓殖子介导。没有明显的症状被归因于迟缓子的休眠。在这篇综述中，我们重新审视了传统的观点慢性弓形虫病在新出现的证据挑战的性质休眠和感染的后果在中枢神经系统。新的和正在出现的数据揭示了一个以前未被认识的水平的生理和复制能力的组织包囊内的缓殖子。这些发现是在重新检查大脑中的慢性感染的背景下出现的，这些感染与神经元结构，神经化学和行为的变化相关，表明慢性感染并非没有后果。研究慢性弓形虫感染进展的新方法的发展所驱动的新数据揭示了被视为休眠状态的重要生理和复制能力。缓殖子和组织囊肿生物学的出现，从什么被视为一个生理学的“黑匣子”提供了令人兴奋的新领域的调查与药物开发的方法，针对这种药物难治性状态的直接影响。此外，对慢性感染的神经生物学研究的新见解揭示了寄生虫，大脑微环境和免疫反应之间复杂而动态的相互作用，导致缓和，促进寄生虫在宿主中的终身持续存在。
Despite over a third of the world’s population being chronically infected with Toxoplasma gondii, little is known about this largely asymptomatic phase of infection. This stage is mediated in vivo by bradyzoites within tissue cysts. The absence of overt symptoms has been attributed to the dormancy of bradyzoites. In this review, we reexamine the conventional view of chronic toxoplasmosis in light of emerging evidence challenging both the nature of dormancy and the consequences of infection in the CNS. New and emerging data reveal a previously unrecognized level of physiological and replicative capacity of bradyzoites within tissue cysts. These findings have emerged in the context of a reexamination of the chronic infection in the brain that correlates with changes in neuronal architecture, neurochemistry, and behavior that suggest that the chronic infection is not without consequence. The emerging data driven by the development of new approaches to study the progression of chronic toxoplasma infection reveals significant physiological and replicative capacity for what has been viewed as a dormant state. The emergence of bradyzoite and tissue cyst biology from what was viewed as a physiological “black box” offers exciting new areas for investigation with direct implications on the approaches to drug development targeting this drug-refractory state. In addition, new insights from studies on the neurobiology on chronic infection reveal a complex and dynamic interplay between the parasite, brain microenvironment, and the immune response that results in the detente that promotes the life-long persistence of the parasite in the host.