The role of anorexia in resistance and tolerance to infections in Drosophila.
The role of anorexia in resistance and tolerance to infections in Drosophila.
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DOI：
10.1371/journal.pbio.1000150
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发表时间：
2009-07
期刊：
影响因子：
9.8
通讯作者：
Schneider DS
中科院分区：
文献类型：
--
作者：
Ayres JS;Schneider DS
感染启动了一个信号循环，在这个循环中，生病的动物变得厌食症，由此导致的饮食变化改变了身体以好的和坏的方式对抗感染的能力。大多数感染会导致厌食症，但其功能(如果有的话)仍不清楚。由于这种反应在动物中很常见，我们假设感染诱导的饮食限制可能是一种适应性特征，调节宿主抵抗感染的能力。有两种防御策略保护宿主免受感染：抵抗力和耐受性，前者是控制病原体水平的能力，后者帮助宿主抵御感染诱导的病理。在这里，我们展示了被感染的果蝇变得厌食，饮食限制改变了防御，提高了果蝇对鼠伤寒沙门氏菌感染的耐受性，同时降低了对单核细胞增多性李斯特菌的抵抗力。这表明，试图通过限制饮食或操纵模仿这一过程的途径来延长寿命，将对宿主抵抗感染的能力产生复杂的影响。降低感染敏感性的两条途径是抵抗力(清除病原体的能力)和耐受性(限制对病原体的损害的能力)。疾病引起的厌食症使动物处于饮食受限的状态，这种状态通常被认为可以延长寿命。我们询问疾病引起的厌食症是否会改变免疫反应。我们测量了饮食限制对果蝇对两种不同感染的抵抗力和耐受性的影响。在一个案例中，我们发现感染导致厌食症，由此产生的饮食限制增加了对这种感染的耐受性，从而增加了感染这种病原体的果蝇的存活率；然而，这并不是普遍的影响。在第二个案例中，我们发现了另一个导致厌食症的病原体，但在这个案例中，饮食限制导致抵抗力降低，从而崩溃了免疫反应，导致苍蝇更快死亡。饮食限制和免疫之间的关系很复杂，必须在病原体的基础上进行评估。
Infections initiate a signaling loop in which sick animals become anorexic, and the resulting change in diet alters the body's ability to fight infections in good and bad ways. Most infections induce anorexia but its function, if any, remains unclear. Because this response is common among animals, we hypothesized that infection-induced diet restriction might be an adaptive trait that modulates the host's ability to fight infection. Two defense strategies protect hosts against infections: resistance, which is the ability to control pathogen levels, and tolerance, which helps the host endure infection-induced pathology. Here we show that infected fruit flies become anorexic and that diet restriction alters defenses, increasing the fly's tolerance to Salmonella typhimurium infections while decreasing resistance to Listeria monocytogenes. This suggests that attempts to extend lifespan through diet restriction or the manipulation of pathways mimicking this process will have complicated effects on a host's ability to fight infections. Two routes to decreasing susceptibility to infection are resistance (the ability to clear pathogens) and tolerance (the ability to limit damage in response to pathogens). Anorexia induced by sickness puts animals into a diet-restricted state, a state that is generally believed to extend lifespan. We asked whether anorexia induced by sickness would alter the immune response. We measured the effects of diet restriction on both resistance and tolerance to two different infections in the fruit fly, Drosophila melanogaster. In one case we found that infection induced anorexia and the resulting diet restriction increased tolerance to this infection, thereby increasing survival of flies infected with this pathogen; however, this is not a universal effect. In a second case we found another pathogen that induced anorexia but here diet restriction lead to a reduction in resistance that collapsed the immune response and caused the fly to die faster. The relationship between diet restriction and immunity is complicated and must be evaluated on a pathogen-by-pathogen basis.
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影响因子：
2.1
作者：
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通讯作者：
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影响因子：
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