Eosinophil and neutrophil ETosis during human filarial infection

丝虫可引起人体衰弱的疾病，如盘尾丝虫病，可导致严重的皮炎和失明。然而，并不是所有的盘尾丝虫病患者都会出现这些临床症状，其他丝虫病物种往往会引起轻度感染。粒细胞通过触发对死亡的微丝虫(MF)(丝虫的后代)的炎症反应，参与了丝虫病引发的症状的发展。我们自己对啮齿动物丝虫的研究表明，在小鼠模型中，嗜酸性粒细胞和中性粒细胞对于保护性免疫反应是必不可少的。在这里，我们发现MF通过Dectin-1诱导嗜酸性粒细胞释放胞外DNA网，从而支持MF的消除。有趣的是，死亡的MF通过不同的信号级联触发更强的ETori反应。基于在小鼠模型中的这些观察，我们假设人类MF也会引起ETsis，并且这种作用在有临床症状的盘尾丝虫病患者的粒细胞中得到增强。因此，在目前的应用中，我们想要比较有和没有临床表现的盘尾丝虫病患者以及地方性、非感染者的嗜酸性粒细胞和中性粒细胞。特别是，将调查它们诱导甲氧西林诱导的内毒素血症的能力。此外，我们还将分析不同丝虫种类的微囊藻毒素是否具有不同的诱发埃希氏菌病的能力。我们假设，通常导致轻度感染的丝虫物种(Mansonella，LOA)比引起临床表现的丝虫物种(Onchocerca)诱导的ETori反应较弱。此外，我们假设死的MF比活的MF诱导更强的ETsis，这是由于内共生沃尔巴克氏菌的识别，这导致了不同的信号级联反应。对含有沃尔巴克氏丝虫(丝虫丝虫、曼氏杆菌)和无沃尔巴克氏丝虫(LOA)的粒细胞ET病的分析，以及对具有不同模式识别受体阻断抗体的活的和死亡的MF的分析将澄清这一点。这些实验将与我们在喀麦隆的长期合作伙伴Wanji教授一起进行。为此，将把在波恩建立的最先进的埃博拉病调查方法移交给喀麦隆。在该项目的框架内，将支持喀麦隆的一名女博士后、两名女博士生和一名硕士以及波恩的一名博士后，并将举办讲习班培训更多的学生。万吉教授接触到丝虫病患者，并拥有成熟的专业知识和基础设施，可以在体外培养人类丝虫并进行免疫学研究。因此，这项申请的目的是将丝虫病的最新发现从动物模型转移到人类身上，这是万吉教授的实验室非常适合的。

Filariae can cause debilitating diseases in humans such as onchocerciasis, which can lead to severe dermatitis and blindness. However, not all onchocerciasis patients develop these clinical pictures and other filarial species often cause mild infections. Granulocytes are involved in the development of onchocerciasis-induced symptoms by triggering inflammatory responses to dying microfilariae (MF), the progeny of filariae. Our own studies with the rodent filariae Litomosoides sigmodontis show that eosinophil and neutrophil granulocytes are essential for protective immune responses in the mouse model. Here, we discovered that MF induce the release of extracellular DNA nets (ETosis) from eosinophils via Dectin-1, thereby supporting MF elimination. Interestingly, dead MF trigger a stronger ETosis response via a different signaling cascade. Based on these observations in the mouse model, we hypothesize that human MF also induce ETosis and that this is enhanced in granulocytes from onchocerciasis patients with clinical symptoms. Therefore, in the present application we would like to compare eosinophils and neutrophils from onchocerciasis patients with and without clinical manifestations as well as endemic, non-infected individuals. In particular, their ability to induce MF-induced ETosis will be investigated. In addition, we will analyze whether MF of different filarial species differ in their ability to induce ETosis. We hypothesize that filarial species that generally lead to mild infections (Mansonella, Loa) induce weaker ETosis responses than filarial species that cause clinical manifestations (Onchocerca). Furthermore, we hypothesize that dead MF induce a stronger ETosis than live MF due to the recognition of endosymbiotic Wolbachia bacteria, which induce a different signaling cascade. Analysis of granulocyte ETosis with Wolbachia-containing filariae (Onchocerca, Mansonella) and Wolbachia-free filariae (Loa) as well as live and dead MF with blocking antibodies for different pattern recognition receptors will clarify this. These experiments will be carried out with our long-term collaboration partner Prof. Wanji in Cameroon. For this purpose, a transfer of the state-of-the-art methods for the investigation of ETosis established in Bonn to Cameroon will take place. Within the framework of this project, a female postdoctoral student, two female PhD students and a master student in Cameroon and a postdoctoral student in Bonn will be supported and workshops will be given to train additional students. Prof. Wanji has access to filariasis patients and the proven expertise and infrastructure to cultivate human filariae in vitro and perform immunological studies. Thus, the aim of this application is to transfer the latest findings in filarial-induced ETosis from animal models to humans, for which Prof. Wanji's laboratory is perfectly suited.