Multiple infections, immune dynamics, and the evolution of virulence
Multiple infections, immune dynamics, and the evolution of virulence
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DOI：
10.1086/590958
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发表时间：
2008-10-01
影响因子：
2.9
通讯作者：
van Baalen, Minus
中科院分区：
文献类型：
--
作者：
Alizon, Samuel;van Baalen, Minus
了解多重感染的影响对于预测（和最终控制）毒力进化至关重要。一些理论研究已经考虑了几种菌株在同一宿主中共存（共感染）的可能性，但很少有人明确考虑它们的宿主内动态。在这里，我们开发了一个嵌套的方法的基础上，一个简单的模型的相互作用的寄生虫菌株与宿主的免疫系统。我们通过将宿主内动态与包含多种感染的流行病学框架联系起来来研究毒力进化。我们的模型表明，抗原相似的寄生虫株不能在宿主体内长期共存。我们还发现，毒力的最佳水平随着多次感染的效率而增加。最后，我们注意到合并感染在宿主群体中产生异质性（易感宿主和受感染宿主），这可能导致寄生虫群体的进化分支和高毒力寄生虫策略的出现。我们将此结果解释为寄生虫对宿主感染状态的专化。我们的研究具有实验和理论意义的毒力管理的角度来看。
Understanding the effect of multiple infections is essential for the prediction (and eventual control) of virulence evolution. Some theoretical studies have considered the possibility that several strains coexist in the same host (coinfection), but few have taken their within-host dynamics explicitly into account. Here, we develop a nested approach based on a simple model for the interaction of parasite strains with their host's immune system. We study virulence evolution by linking the within-host dynamics to an epidemiological framework that incorporates multiple infections. Our model suggests that antigenically similar parasite strains cannot coexist in the long term inside a host. We also find that the optimal level of virulence increases with the efficiency of multiple infections. Finally, we notice that coinfections create heterogeneity in the host population (with susceptible hosts and infected hosts), which can lead to evolutionary branching in the parasite population and the emergence of a hypervirulent parasite strategy. We interpret this result as a parasite specialization to the infectious state of the hosts. Our study has experimental and theoretical implications in a virulence management perspective.