House Finch Populations Differ in Early Inflammatory Signaling and Pathogen Tolerance at the Peak of Mycoplasma gallisepticum Infection
House Finch Populations Differ in Early Inflammatory Signaling and Pathogen Tolerance at the Peak of Mycoplasma gallisepticum Infection
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DOI：
10.1086/670024
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发表时间：
2013-05-01
影响因子：
2.9
通讯作者：
Hawley, Dana M.
中科院分区：
文献类型：
--
作者：
Adelman, James S.;Kirkpatrick, Laila;Hawley, Dana M.
宿主个体和种群对感染的反应往往不同，对病原体的传播和进化有直接影响。虽然相当多的工作集中在抗性差异的机制上杀死病原体的能力，但我们对耐受性的机制知之甚少，耐受性是将每单位病原体的适应性损失降至最低的能力。在这里，我们研究的模式和机制之间的耐受性的两个种群的家雀（Haemorhous [原Carpodacus]墨西哥）与不同的历史与细菌病原体鸡毒支原体（MG）。在一个共同的环境中感染后，我们评估了两个指标的病理，质量损失和眼部病变的严重程度，作为代理的健身。我们使用两种方法计算耐受性，一种基于感染高峰时的病理学和病原体负荷（点耐受性），另一种基于这些指标随时间的积分（范围耐受性）。亚拉巴马鸟，这有一个显着更长的历史暴露于MG，表现出更明显的点比亚利桑那州的鸟类的耐受性，而范围的耐受性没有不同的人群。亚拉巴马鸟在感染早期也表现出较低的炎性细胞因子信号传导和较低的发热。这些结果表明，炎症过程的差异，这可能会显着损害宿主组织，可能有助于家雀个体和种群之间的耐受性的变化。这种变异可以影响病原体的传播和进化，其方式无法单独通过抗性来预测，并揭示了野生动物炎症的成本和收益。
Host individuals and populations often vary in their responses to infection, with direct consequences for pathogen spread and evolution. While considerable work has focused on the mechanisms underlying differences in resistance-the ability to kill pathogens-we know little about the mechanisms underlying tolerance-the ability to minimize fitness losses per unit pathogen. Here, we examine patterns and mechanisms of tolerance between two populations of house finches (Haemorhous [formerly Carpodacus] mexicanus) with different histories with the bacterial pathogen Mycoplasma gallisepticum (MG). After infection in a common environment, we assessed two metrics of pathology, mass loss and eye lesion severity, as proxies for fitness. We calculated tolerance using two methods, one based on pathology and pathogen load at the peak of infection (point tolerance) and the other based on the integrals of these metrics over time (range tolerance). Alabama birds, which have a significantly longer history of exposure to MG, showed more pronounced point tolerance than Arizona birds, while range tolerance did not differ between populations. Alabama birds also displayed lower inflammatory cytokine signaling and lower fever early in infection. These results suggest that differences in inflammatory processes, which can significantly damage host tissues, may contribute to variation in tolerance among house finch individuals and populations. Such variation can affect pathogen spread and evolution in ways not predictable by resistance alone and sheds light on the costs and benefits of inflammation in wild animals.