Tamarozzi Francesca, Turner Joseph D, Pionnier Nicolas, Midgley Angela, Guimaraes Ana F, Johnston Kelly L, Edwards Steven W, Taylor Mark J
Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place L3 5QA, Liverpool, UK.
Department of Women's and Children's Health, Alder Hey NHS Foundation Trust, Eaton Road L12 2AP, Liverpool, UK.
Sci Rep. 2016 Oct 18;6:35559. doi: 10.1038/srep35559.
The endosymbiotic bacteria, Wolbachia, induce neutrophilic responses to the human helminth pathogen Onchocerca volvulus. The formation of Neutrophil Extracellular Traps (NETs), has been implicated in anti-microbial defence, but has not been identified in human helminth infection. Here, we demonstrate NETs formation in human onchocerciasis. Extracellular NETs and neutrophils were visualised around O. volvulus in nodules excised from untreated patients but not in nodules from patients treated with the anti-Wolbachia drug, doxycycline. Whole Wolbachia or microspheres coated with a synthetic Wolbachia lipopeptide (WoLP) of the major nematode Wolbachia TLR2/6 ligand, peptidoglycan associated lipoprotein, induced NETosis in human neutrophils in vitro. TLR6 dependency of Wolbachia and WoLP NETosis was demonstrated using purified neutrophils from TLR6 deficient mice. Thus, we demonstrate for the first time that NETosis occurs during natural human helminth infection and demonstrate a mechanism of NETosis induction via Wolbachia endobacteria and direct ligation of Wolbachia lipoprotein by neutrophil TLR2/6.
内共生细菌沃尔巴克氏体可诱导对人类蠕虫病原体盘尾丝虫的嗜中性粒细胞反应。中性粒细胞胞外陷阱（NETs）的形成与抗菌防御有关，但在人类蠕虫感染中尚未得到证实。在此，我们证明了人类盘尾丝虫病中存在NETs形成。在从未经治疗的患者切除的结节中，可在盘尾丝虫周围观察到细胞外NETs和中性粒细胞，而在接受抗沃尔巴克氏体药物强力霉素治疗的患者的结节中则未观察到。完整的沃尔巴克氏体或包被有主要线虫沃尔巴克氏体TLR2/6配体肽聚糖相关脂蛋白的合成沃尔巴克氏体脂肽（WoLP）的微球，在体外可诱导人类中性粒细胞发生NETosis。使用来自TLR6缺陷小鼠的纯化中性粒细胞，证明了沃尔巴克氏体和WoLP诱导的NETosis对TLR6的依赖性。因此，我们首次证明了在自然人类蠕虫感染期间会发生NETosis，并证明了通过沃尔巴克氏体内细菌以及中性粒细胞TLR2/6直接连接沃尔巴克氏体脂蛋白诱导NETosis的机制。
