The role of neutrophil extracellular trap formation in equine recurrent uveitis (ERU)

马复发性葡萄膜炎（ERU）是马失明的主要原因，10%的欧洲马受到影响。值得注意的是，ERU是人类自身免疫性葡萄膜炎的重要可用模型，因为其临床和免疫病理特征相似。作为ERU的原因，文献中描述了各种假设。一方面，讨论了钩端螺旋体感染以及其他细菌、寄生虫或病毒感染。独立的初始原因，有许多迹象表明，ERU是一种免疫介导的疾病。在体内原发感染得到控制后，免疫系统会对激活的免疫细胞产生过度反应。除了淋巴细胞外，这些免疫细胞还可以是中性粒细胞。在各种抗菌功能中，中性粒细胞已被证明释放中性粒细胞胞外陷阱（NETs）。net是细胞外DNA纤维，具有相关的蛋白酶和抗菌肽，由活化细胞释放。NETs介导入侵病原体的诱捕，但当大量释放时可能导致宿主的有害自身免疫反应。本文提出的研究项目旨在为NETs在ERU发病机制中的作用提供必要的见解。在我们研究的第一阶段，我们的发现表明NETs参与了ERU的发病机制，并产生了有害的影响。简而言之，NET与疾病严重程度相关，似乎会损害血液视网膜细胞，并诱导针对NET蛋白的自身抗体。我们假设，这些自身抗体可能保护NETs免受dna酶的降解，从而导致它们的持续存在，并可能导致新的疾病发作。因此，在当前的项目中，我们的目标是表征疾病阶段（非活性静止期与急性炎症期）是否以及如何影响细胞参与和细胞外DNA释放。根据我们之前的数据，我们进一步假设，在ERU的进展过程中，除了中性粒细胞外，不同类型的细胞还参与细胞外DNA释放，从而使各种免疫细胞之间产生串扰。因此，我们将研究除中性粒细胞外的其他免疫细胞对ETs的释放及其与适应性免疫细胞的相互作用。最后，由于庆大霉素在ERU患者治疗中的应用已经确立，目的是确定不同浓度的庆大霉素以及不同的刺激对马免疫细胞的影响，重点是ET的释放。

The equine recurrent uveitis (ERU) is the main reason for blindness in horses, and 10% of the european horses are affected. Significantly, ERU is an important available model for human autoimmune uveitis as the clinical and immune-pathological characteristics are similar. As a cause for ERU, various hypotheses are described in the literature. On the one hand, infections with Leptospira interrogans are discussed as well as other bacterial, parasitic or viral infections. Independent of the initiating cause, there are numerous indications that ERU is an immune-mediated disease. In the body after the control of the primary infection, an overreaction of the immune system occurs in response to activated immune cells. In addition to lymphocytes, these immune cells can also be neutrophil granulocytes. Among various antimicrobial functions, neutrophils have been shown to release neutrophil extracellular traps (NETs). NETs are extracellular DNA fibers with associated proteases and antimicrobial peptides which are released by activated cells. NETs mediate entrap of invading pathogens, but when massively released may contribute to detrimental autoimmune reactions of the host. The research project presented here is intended to provide essential insights for the involvement of NETs in the pathogenesis of ERU. In the first phase of our study, our findings indicate an involvement of NETs in the pathogenesis of ERU with detrimental effects. In short, NETs correlate to disease severity, seem to damage the blood retinal cells, and induce autoantibodies against NET proteins. We hypothesize, that those autoantibodies might shield the NETs from degradation by DNases, resulting in their persistence and potentially in new disease episodes. Thus, in the current project we aim to characterize if and how the phase of disease (non-active quiescent phase versus acute inflammatory phase) influences cellular involvement and extracellular DNA release. Based on our previous data, we further hypothesize that different cell types besides neutrophils play a role in extracellular DNA release during the progression of ERU, which enables crosstalk between various immune cells. Therefore, we will study the release of ETs by other immune cells besides neutrophils and its interplay with adaptive immune cells. Finally, since the use of gentamicin in the treatment of ERU patients is established, the aim is to determine the influence of gentamicin in varying concentrations and along with distinct stimuli on equine immune cells, focusing on ET release.