Adaptation to low parasite abundance affects immune investment and immunopathological responses of cavefish
Adaptation to low parasite abundance affects immune investment and immunopathological responses of cavefish
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DOI：
10.1038/s41559-020-1234-2
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发表时间：
2020-07-20
影响因子：
16.8
通讯作者：
Rohner, Nicolas
中科院分区：
文献类型：
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作者：
Peuss, Robert;Box, Andrew C.;Rohner, Nicolas
发达国家寄生虫感染率的降低被怀疑是自身免疫性疾病患病率上升的原因。然而，减少寄生虫暴露对免疫系统的长期进化后果还没有得到很好的理解。我们使用墨西哥tetraAstyanax mexicanusto了解如何损失的寄生虫多样性影响脊椎动物免疫系统的进化轨迹，通过比较河流和洞穴形态。在这里，我们提出的实地数据肯定了洞穴生态系统中寄生虫多样性的大幅减少，并表明洞穴鱼免疫细胞对细菌内毒素表现出更敏感的促炎反应。令人惊讶的是，其他先天性细胞免疫反应，如吞噬作用，在洞穴鱼中急剧下降。使用两种独立的单细胞方法，我们确定了洞穴鱼类整体免疫细胞组成的变化作为潜在的细胞机制，表明免疫投资策略存在很大差异。虽然表面鱼类对先天免疫系统和适应性免疫系统的投资是均匀的，但洞穴鱼将免疫投资转移到适应性免疫系统，在这里，主要针对促进体内平衡的特定T细胞群体。此外，内脏脂肪组织中的炎症反应和免疫病理表型在洞穴鱼中急剧减少。我们的数据表明，长期适应低寄生虫多样性与洞穴鱼中更敏感的免疫系统相一致，这伴随着在介导促炎症反应中发挥作用的免疫细胞的减少。作者表明，先天性和适应性免疫系统的敏感性增加，伴随着先天性免疫系统的投资减少，作为对寄生虫多样性降低的进化反应。
Reduced parasitic infection rates in the developed world are suspected to underlie the rising prevalence of autoimmune disorders. However, the long-term evolutionary consequences of decreased parasite exposure on an immune system are not well understood. We used the Mexican tetraAstyanax mexicanusto understand how loss of parasite diversity influences the evolutionary trajectory of the vertebrate immune system, by comparing river with cave morphotypes. Here, we present field data affirming a strong reduction in parasite diversity in the cave ecosystem, and show that cavefish immune cells display a more sensitive pro-inflammatory response towards bacterial endotoxins. Surprisingly, other innate cellular immune responses, such as phagocytosis, are drastically decreased in cavefish. Using two independent single-cell approaches, we identified a shift in the overall immune cell composition in cavefish as the underlying cellular mechanism, indicating strong differences in the immune investment strategy. While surface fish invest evenly into the innate and adaptive immune systems, cavefish shifted immune investment to the adaptive immune system, and here, mainly towards specific T-cell populations that promote homeostasis. Additionally, inflammatory responses and immunopathological phenotypes in visceral adipose tissue are drastically reduced in cavefish. Our data indicate that long-term adaptation to low parasite diversity coincides with a more sensitive immune system in cavefish, which is accompanied by a reduction in the immune cells that play a role in mediating the pro-inflammatory response.Comparing Mexican cavefish from rivers with those from caves, the authors show increased sensitivity of the innate and adaptive immune system that is accompanied by a reduced investment in the innate immune system as an evolutionary response to lower parasite diversity.