From Host Immunity to Pathogen Invasion: The Effects of Helminth Coinfection on the Dynamics of Microparasites
From Host Immunity to Pathogen Invasion: The Effects of Helminth Coinfection on the Dynamics of Microparasites
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DOI：
10.1093/icb/icr058
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发表时间：
2011-10-01
影响因子：
2.6
通讯作者：
Jolles, Anna E.
中科院分区：
文献类型：
--
作者：
Ezenwa, Vanessa O.;Jolles, Anna E.
多种寄生虫的并发感染在自然界中普遍存在。共感染寄生虫可以以多种方式相互作用，包括通过宿主的免疫系统通过免疫权衡和免疫抑制等机制。这些介导寄生虫之间相互作用的宿主内免疫过程已被详细描述，但它们如何扩大规模以确定人口水平的疾病动态模式才刚刚开始探索。在这篇综述中，我们使用蠕虫，微寄生虫共感染作为一个模型，研究如何在宿主内的免疫效应可能会影响微寄生虫病的生态结果，特别关注疾病的入侵。目前的文献蠕虫和主要的微寄生虫病之间的共感染包括许多研究记录蠕虫对个体宿主的反应，微寄生虫的影响。在许多情况下，观察到的主机反应直接映射到量化疾病动力学相关的参数，但是，很少有人尝试将个人水平的影响数据整合到理论模型中，从个人到群体水平进行外推。此外，在不同的微寄生虫系统中，蠕虫影响的疾病参数的特定组合存在相当大的差异。我们开发了一个概念框架，确定了一些潜在的来源，这种变异性：病原体的持久性和严重性，以及资源的可用性主机。我们还产生可检验的假设，疾病和环境背景时，蠕虫对微寄生虫动态的影响应该是最明显的。最后，我们用一个案例研究蠕虫和分枝杆菌共感染的非洲布法罗，以说明在理解宿主内免疫相互作用的人口水平的后果的进展和挑战，并得出结论，为未来的研究，这将有助于提高我们的理解的影响，共感染传染病的动态。
Concurrent infections with multiple parasites are ubiquitous in nature. Coinfecting parasites can interact with one another in a variety of ways, including through the host's immune system via mechanisms such as immune trade-offs and immunosuppression. These within-host immune processes mediating interactions among parasites have been described in detail, but how they scale up to determine disease dynamic patterns at the population level is only beginning to be explored. In this review, we use helminth-microparasite coinfection as a model for examining how within-host immunological effects may influence the ecological outcome of microparasitic diseases, with a specific focus on disease invasion. The current literature on coinfection between helminths and major microparasitic diseases includes many studies documenting the effects of helminths on individual host responses to microparasites. In many cases, the observed host responses map directly onto parameters relevant for quantifying disease dynamics; however, there have been few attempts at integrating data on individual-level effects into theoretical models to extrapolate from the individual to the population level. Moreover, there is considerable variability in the particular combination of disease parameters affected by helminths across different microparasite systems. We develop a conceptual framework identifying some potential sources of such variability: Pathogen persistence and severity, and resource availability to hosts. We also generate testable hypotheses regarding diseases and the environmental contexts when the effects of helminths on microparasite dynamics should be most pronounced. Finally, we use a case study of helminth and mycobacterial coinfection in the African buffalo to illustrate both progress and challenges in understanding the population-level consequences of within-host immunological interactions, and conclude with suggestions for future research that will help improve our understanding of the effects of coinfection on dynamics of infectious diseases.