PNAS:宿主免疫力、气候变暖与寄生虫感染
气候变暖预计将增加寄生虫感染的风险与传播，而美国宾夕法尼亚州立大学一项研究报告说，变暖对寄生虫感染的效应可能受到宿主对寄生虫免疫力的变化的影响。Isabella M. Cattadori及其同事探索了两种土壤传播的兔消化道蠕虫——曲颈瓶形毛圆线虫(Trichostrongylus retortaeformis)和Graphidum strigosum的疾病动态，这些寄生虫是在1977年到2002年之间每月在苏格兰采样的。牧场的感染性寄生虫随着温度和湿度的增加而增加，这组作者发现，寄生虫在兔子体内的积累取决于宿主对这些蠕虫的免疫应答。由于G. strigosum的感染不受兔子的免疫应答的控制，这种寄生虫感染的强度随着变暖而增加，导致了G. strigosum在宿主种群中的显著积累，在成年兔体内有最大的寄生虫载量。相比之下，曲颈瓶形毛圆线虫(Trichostrongylus retortaeformis)感染受到了兔子的免疫系统的控制，抵消了气候的效应并导致了随着时间推移在这个兔子种群中的相对恒定的感染强度。然而，气候变化把曲颈瓶形毛圆线虫(Trichostrongylus retortaeformis)感染的季节峰值朝着缺乏强免疫应答的年轻宿主偏移，这证明了长期气候变暖如何能够影响这种寄生虫在感染和传播方面的季节变化。这组作者说，这项研究证明了气候变化与宿主免疫力之间的相互作用如何能够影响寄生虫感染。
原文链接：
Host immunity shapes the impact of climate changes on the dynamics of parasite infections
原文摘要：
global climate change is predicted to alter the distribution and dynamics of soil-transmitted helminth infections, and yet host immunity can also influence the impact of warming on host–parasite interactions and mitigate the long-term effects. We used time-series data from two helminth species of a natural herbivore and investigated the contribution of climate change and immunity on the long-term and seasonal dynamics of infection. We provide evidence that climate warming increases the availABIlity of infective stages of both helminth species and the proportional increase in the intensity of infection for the helminth not regulated by immunity. In contrast, there is no significant long-term positive trend in the intensity for the immune-controlled helminth, as immunity reduces the net outcome of climate on parasite dynamics. Even so, hosts experienced higher infections of this helminth at an earlier age during critical months in the warmer years. Immunity can alleviate the expected long-term effect of climate on parasite infections but can also shift the seasonal peak of infection toward the younger individuals.
作者：Andrea Mignatti
