Epithelial defense in Hydra

刺胞动物门是动物生命树中最早的分支之一。刺胞动物拥有大部分在bilalerians中发现的基因家族，并且与许多在果蝇和C.优雅因此，现有的刺胞动物的先天免疫库的特性，是根本和应用的兴趣-它不仅提供了深入了解所有动物的共同祖先的基本免疫工具包，但也可能是重要的，在了解人类屏障疾病通过描述古老的机制主机/微生物的相互作用和进化选择过程。在过去的几年里，我们已经取得了相当大的进展，在水螅，已知的最简单的多细胞动物之一的先天免疫系统的特点。在完全缺乏保护性机械屏障和移动的吞噬细胞的情况下。九头蛇是非常好的装备，以防止病原体感染。我们的研究结果揭示了高活性的抗菌肽和一个复杂的遗传网络参与了后生动物进化开始时宿主和微生物群的相互作用。这些观察结果支持了上皮代表宿主防御的古老系统的假设。与此相一致，我们已经表明水螅中的上皮细胞在选择其微生物群方面发挥着积极作用，并提出抗菌肽是宿主-细菌共同进化的关键因素。我们现在建议更详细地研究水螅中的先天免疫反应，最终目标是：（i）了解水螅上皮细胞与相关微生物群落的相互作用;（ii）将糖杯表征为微生物防御中尚未理解的物理屏障;（iii）表征分泌腺细胞在防御反应中的作用;以及（iv）鉴定抗真菌分子。

The phylum Cnidaria is one ofthe earliest branches in the animal tree of life. Cnidarians possess most of the gene families found in bilalerians and have relained many ancestral genes that have been lost in Drosophila and C. elegans. Characterisation of the innate immune repertoire of extant cnidarians is, therefore, of both fundamental and applied interest - it not only provides insights into the basic immunological tool kit of the common ancestor of all animals, but is also likely to be important in understanding human barrier disorders by describing ancient mechanisms of host/microbial interactions and the resulting evolutionary selection processes. In the last few years we have made considerable progress in characterizing the innate immune system in Hydra, one of the simplest multicellular animals known. In the complete absence of both protective mechanical barriers and mobile phagocytes. Hydra is remarkably well equipped to prevent pathogens infection. Our findings reveal highly active antimicrobial peptides and a complex genetic network involved in the interaction of host and microbiota at the beginning of metazoan evolution. The observations support the hypothesis that the epithelium represents the ancient system of host defense. Consistent with that, we have shown that epithelia in Hydra play an active role in selecting their microbiota and have proposed that antimicrobial peptides are key factors for host-bacteria coevolution. We now propose to study innate immune reactions in Hydra in more detail with the final goal of, (i) understanding the interactions of hydra epithelia with the associated microbial community; (ii) characterization of the glycocalix as a not yet understood physical barrier in microbial defence; (iii) characterizing the role of secretory gland cells in defence reactions; and (iv) identification of antifungal molecules.