Juvenile immune system activation induces a costly upregulation of adult immunity in field crickets Gryllus campestris
Juvenile immune system activation induces a costly upregulation of adult immunity in field crickets Gryllus campestris
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DOI：
10.1098/rspb.2004.2919
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发表时间：
2005-01-07
影响因子：
4.7
通讯作者：
Brinkhof, MWG
中科院分区：
文献类型：
--
作者：
Jacot, A;Scheuber, H;Brinkhof, MWG
诱导免疫防御可能允许生物体的状态依赖性上调昂贵的免疫，以尽量减少预期的未来寄生虫的风险。免疫活性升高的基本代价可能包括其他健康相关性状的减少以及免疫病理学风险的增加。以雄性蟋蟀为实验对象，研究了蟋蟀免疫系统激活对成年期免疫和生理状态的影响。若虫注射细菌脂多糖后，成年男性表现出显着升高的水平，两个主要的免疫参数，即血淋巴抗菌活性和酚氧化酶原（proPO）的浓度。相比之下，活性酶，酚氧化酶（PO），并没有增加，这表明一个战略性的长期上调无活性的酶原proPO。这可能有助于避免与高活性酶水平相关的细胞毒性效应。若虫免疫损伤进一步导致成虫血淋巴蛋白负荷减少，表明总体代谢状况长期下降。若虫的食物供应积极影响成人溶菌酶活性，而PO和proPO浓度没有受到影响。因此，我们的数据表明，长期上调免疫反应的抗原线索作为一种适应性，但昂贵的，无脊椎动物的策略，以提高抵抗未来的寄生虫。
Inducible immune defence may allow organisms a state-dependent upregulation of costly immunity in order to minimize the risk of anticipated future parasitism. The basic costs of elevated immune activity might involve a reduction in other fitness-related traits as well as an increased risk of immunopathology. In male field crickets Gryllus campestris we experimentally investigated the condition-dependent effects of immune system activation in nymphs on immunity and physiological condition during adulthood. Following a nymphal injection of bacterial lipopolysaccharides, adult males showed significantly elevated levels of two major immune parameters, i.e. haemolymph antibacterial activity and the concentration of prophenoloxidase (proPO). By contrast, the active enzyme, phenoloxidase (PO), did not increase, suggesting a strategic long-term upregulation of the inactive proenzyme proPO only. This may help avoid the cytotoxic effects associated with high standing levels of the active enzyme. The nymphal immune insult further caused a reduction in adult haemolymph protein load, suggesting a long-term decline in overall metabolic condition. Nymphal food availability positively affected adult lysozyme activity, while PO and proPO concentrations were not affected. Our data thus suggest the long-term upregulation of immunity in response to antigenic cues as an adaptive, yet costly, invertebrate strategy to improve resistance to future parasitism.