On sexual dimorphism in immune function
On sexual dimorphism in immune function
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DOI：
10.1098/rstb.2008.0148
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发表时间：
2009-01-12
影响因子：
6.3
通讯作者：
Rolff, Jens
中科院分区：
文献类型：
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作者：
Nunn, Charles L.;Lindenfors, Patrik;Rolff, Jens
免疫功能中的性别二型性是脊椎动物和许多无脊椎动物的常见模式。大多数情况下，女性比男性具有更强的“免疫能力”。潜在的原因要么是免疫抑制物质(如睾酮)的作用，要么是男性和女性生活史上的根本差异。在这里，我们使用哺乳动物在一个比较的框架内调查了免疫能力障碍假说(ICHH)的一些主要预测。我们特别关注的预测是，跨物种的性竞争衡量标准解释了观察到的物种内性别特异性免疫能力的变化模式。我们的结果与ICHH不一致，但我们确实发现雌性哺乳动物往往有更高的白细胞计数(WBC)，细胞计数和雌性寿命之间有一些进一步的联系。我们还记录了免疫中的性别二型性和有效繁殖持续时间中的二型性之间的正协方差。这与‘贝特曼原理’在免疫方面的应用是一致的，即女性通过在免疫防御上投入更多资金来延长寿命，从而最大限度地提高健康水平。此外，我们提出了昆虫免疫的荟萃分析，因为昆虫中缺乏睾丸激素为研究贝特曼的免疫原理提供了一种独立于ICHH的方法。在这里，我们还发现，我们研究的昆虫免疫功能的两个组成部分之一(酚氧化酶)的表达存在系统性的雌性偏见。从这些分析中，我们得出结论，对非物质文化遗产的机制解释缺乏经验支持。相反，与健康相关的性别差异可能足以解释免疫能力的许多自然模式。
Sexual dimorphism in immune function is a common pattern in vertebrates and also in a number of invertebrates. Most often, females are more 'immunocompetent' than males. The underlying causes are explained by either the role of immunosuppressive substances, such as testosterone, or by fundamental differences in male and female life histories. Here, we investigate some of the main predictions of the immunocompetence handicap hypothesis (ICHH) in a comparative framework using mammals. We focus specifically on the prediction that measures of sexual competition across species explain the observed patterns of variation in sex-specific immunocompetence within species. Our results are not consistent with the ICHH, but we do find that female mammals tend to have higher white blood cell counts (WBC), with some further associations between cell counts and longevity in females. We also document positive covariance between sexual dimorphism in immunity, as measured by a subset of WBC, and dimorphism in the duration of effective breeding. This is consistent with the application of 'Bateman's principle' to immunity, with females maximizing fitness by lengthening lifespan through greater investment in immune defences. Moreover, we present a meta-analysis of insect immunity, as the lack of testosterone in insects provides a means to investigate Bateman's principle for immunity independently of the ICHH. Here, we also find a systematic female bias in the expression of one of the two components of insect immune function that we investigated ( phenoloxidase). From these analyses, we conclude that the mechanistic explanations of the ICHH lack empirical support. Instead, fitness-related differences between the sexes are potentially sufficient to explain many natural patterns in immunocompetence.