Dziedziech Alexis, Shivankar Sai, Theopold Ulrich
Department of Molecular Biosciences, The Wenner-Gren Institute (MBW), Stockholm University,10691 Stockholm, Sweden.
Insects. 2020 Jan 19;11(1):62. doi: 10.3390/insects11010062.
Several insect innate immune mechanisms are activated in response to infection by entomopathogenic nematodes (EPNs). In this review, we focus on the coagulation of hemolymph, which acts to stop bleeding after injury and prevent access of pathogens to the body cavity. After providing a general overview of invertebrate coagulation systems, we discuss recent findings in which demonstrate that clots protect against EPN infections. Detailed analysis at the cellular level provided insight into the kinetics of the secretion of coagulation factors, including non-classical modes of secretion. Roughly, clot formation can be divided into a primary phase in which crosslinking of clot components depends on the activity of transglutaminase and a secondary, phenoloxidase (PO)-dependent phase, characterized by further hardening and melanization of the clot matrix. These two phases appear to play distinct roles in two commonly used EPN infection models, namely and . Finally, we discuss the implications of the coevolution between parasites such as EPNs and their hosts for the dynamics of coagulation factor evolution.
昆虫的几种先天免疫机制会因昆虫病原线虫（EPNs）感染而被激活。在本综述中，我们重点关注血淋巴的凝固，它在受伤后起到止血作用，并防止病原体进入体腔。在对无脊椎动物凝血系统进行总体概述后，我们讨论了最近的研究发现，这些发现表明凝块可抵御EPN感染。在细胞水平上的详细分析深入了解了凝血因子的分泌动力学，包括非经典分泌模式。大致来说，凝块形成可分为两个阶段，第一阶段凝块成分的交联依赖于转谷氨酰胺酶的活性，第二阶段是依赖酚氧化酶（PO）的阶段，其特征是凝块基质进一步硬化和黑化。这两个阶段似乎在两种常用的EPN感染模型中发挥着不同的作用，即 和 。最后，我们讨论了诸如EPNs等寄生虫与其宿主之间的共同进化对凝血因子进化动态的影响。
