Evolution of parasite virulence when host responses cause disease
Evolution of parasite virulence when host responses cause disease
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DOI：
10.1098/rspb.2007.0809
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发表时间：
2007-11-07
影响因子：
4.7
通讯作者：
Read, Andrew F.
中科院分区：
文献类型：
--
作者：
Day, Troy;Graham, Andrea L.;Read, Andrew F.
毒力进化的权衡假设基于这样的假设，即感染诱导的死亡率是寄生虫利用宿主的结果。尽管越来越多的证据表明，感染诱导的死亡率往往是宿主免疫反应的副产品，但这一假设是许多毒力进化的经验和理论研究的核心。我们扩展了权衡假设的理论框架，将这种免疫病理学，并探讨宿主防御机制的这一有害方面如何影响病原体利用的演变，从而感染诱导的死亡率。我们认为，免疫病理学可以产生质的不同的方式，并建议经验研究可以梳理这些影响的方式。我们发现，免疫病理学可以导致感染引起的死亡率增加或减少作为病原体进化的结果，这取决于它如何与病原体开发策略和宿主杀死寄生虫。因此，免疫病理学是公共和动物卫生计划是否会推动临床有益或有害方向的重要决定因素。免疫病理学使我们对疾病演变的理解复杂化，但仍然可以在权衡假设的框架内很容易地解释。
The trade-off hypothesis of virulence evolution rests on the assumption that infection-induced mortality is a consequence of host exploitation by parasites. This hypothesis lies at the heart of many empirical and theoretical studies of virulence evolution, despite growing evidence that infection-induced mortality is very often a by-product of host immune responses. We extend the theoretical framework of the trade-off hypothesis to incorporate such immunopathology and explore how this detrimental aspect of host defence mechanisms affects the evolution of pathogen exploitation and hence infection-induced mortality. We argue that there are qualitatively different ways in which immunopathology can arise and suggest ways in which empirical studies can tease apart these effects. We show that immunopathology can cause infection-induced mortality to increase or decrease as a result of pathogen evolution, depending on how it covaries with pathogen exploitation strategies and with parasite killing by hosts. Immunopathology is thus an important determinant of whether public and animal health programmes will drive evolution in a clinically beneficial or detrimental direction. Immunopathology complicates our understanding of disease evolution, but can nevertheless be readily accounted for within the framework of the trade-off hypothesis.