School of Biological Sciences, University of Liverpool, Crown Street, Liverpool L69 7ZB, UK.
Parasitology. 2010 May;137(6):1027-38. doi: 10.1017/S0031182009991788. Epub 2010 Feb 15.
Predator-prey models are often applied to the interactions between host immunity and parasite growth. A key component of these models is the immune system's functional response, the relationship between immune activity and parasite load. Typically, models assume a simple, linear functional response. However, based on the mechanistic interactions between parasites and immunity we argue that alternative forms are more likely, resulting in very different predictions, ranging from parasite exclusion to chronic infection. By extending this framework to consider multiple infections we show that combinations of parasites eliciting different functional responses greatly affect community stability. Indeed, some parasites may stabilize other species that would be unstable if infecting alone. Therefore hosts' immune systems may have adapted to tolerate certain parasites, rather than clear them and risk erratic parasite dynamics. We urge for more detailed empirical information relating immune activity to parasite load to enable better predictions of the dynamic consequences of immune-mediated interspecific interactions within parasite communities.
捕食者-猎物模型常用于研究宿主免疫和寄生虫生长之间的相互作用。这些模型的一个关键组成部分是免疫系统的功能反应，即免疫活性和寄生虫负荷之间的关系。通常，模型假设一个简单的线性功能反应。然而，基于寄生虫和免疫之间的机制相互作用，我们认为替代形式更有可能，从而产生非常不同的预测，从寄生虫排除到慢性感染。通过将这个框架扩展到考虑多种感染，我们表明，引起不同功能反应的寄生虫的组合会极大地影响群落稳定性。事实上，某些寄生虫可能会稳定其他单独感染时不稳定的物种。因此，宿主的免疫系统可能已经适应了容忍某些寄生虫，而不是清除它们并冒着寄生虫动态不稳定的风险。我们敦促提供更多关于免疫活性与寄生虫负荷相关的详细实证信息，以便更好地预测寄生虫群落中免疫介导的种间相互作用的动态后果。
