Emory University School of Medicine, Atlanta, Georgia.
J Exp Zool A Ecol Integr Physiol. 2019 Nov;331(9):478-484. doi: 10.1002/jez.2314. Epub 2019 Aug 7.
Invasive species have become a prolific environmental issue, second only to climate change, yet many of the phenomena that facilitate invasive success are not well understood (Phillip & Shine, Proc. Roy. Soc. B, 273, 1545-1550). The combination of several generalist life-history traits, certain physiological mechanisms, and environmental conditions is thought to play a significant role in invasion success. The ability to undergo fitness trade-offs-to reallocate nutritional and energetic resources towards processes that increase reproduction, growth, and dispersal-is also thought to be an adaptive quality of many invasive species. Due to their inherent flexibility, phenotypically plastic traits in particular are often targeted for fitness reallocations. Immune function, for example, is determined by a highly plastic phenotype, which is crucial for combating a diverse array of pathogens. When active, immune function also demands extensive resources from the host. Laboratory and field studies suggest that certain aspects of the immune system are more costly than others, though, and that its components can be regulated independent of one another. In invasive species undergoing fitness trade-offs, costly innate inflammatory responses are often downregulated, while antibody-mediated responses may be enhanced. A combination of fixed physiological responses and environmentally induced trade-offs are thought to regulate the immune system, though the relationship between these facets of regulation is still an area of active research. The field of ecoimmunology, then, has emerged in effort to understand the phenomena by which individual immune regulation can drive (and be driven by) species-level ecology and evolution, and therefore be linked to invasive success (Downs et al., 2014. Integr. Compar. Biol., 54, 340-352).
入侵物种已经成为一个多产的环境问题，仅次于气候变化，但许多促进入侵成功的现象还没有得到很好的理解（菲利普和夏恩，Proc。罗伊。 Soc. B，273，1545-1550）。几种一般生活史特征、某些生理机制和环境条件的结合被认为在入侵成功中起着重要作用。能够进行适应性权衡——将营养和能量资源重新分配到增加繁殖、生长和扩散的过程中——也被认为是许多入侵物种的适应性特征。由于其固有的灵活性，表型可塑性特征通常是适应性权衡的目标。例如，免疫功能由一个高度可塑性的表型决定，这对抵御各种病原体至关重要。当免疫功能活跃时，它也需要宿主提供大量资源。实验室和现场研究表明，免疫系统的某些方面比其他方面成本更高，尽管它的组成部分可以相互独立调节。在进行适应性权衡的入侵物种中，昂贵的先天炎症反应通常会被下调，而抗体介导的反应可能会增强。固定的生理反应和环境诱导的权衡的结合被认为可以调节免疫系统，尽管这些调节方面之间的关系仍然是一个活跃的研究领域。生态免疫学领域的出现是为了努力理解个体免疫调节如何驱动（并被物种水平的生态学和进化所驱动），并因此与入侵成功相关（唐斯等人，2014 年。综合。比较。 Biol.，54，340-352）。
