table_2_Hookworm Secreted Extracellular Vesicles Interact With Host Cells and Prevent Inducible Colitis in Mice.xlsx

Gastrointestinal (GI) parasites, hookworms in particular, have evolved to cause minimal harm to their hosts, allowing them to establish chronic infections. This is mediated by creating an immunoregulatory environment. Indeed, hookworms are such potent suppressors of inflammation that they have been used in clinical trials to treat inflammatory bowel diseases (IBD) and celiac disease. Since the recent description of helminths (worms) secreting extracellular vesicles (EVs), exosome-like EVs from different helminths have been characterized and their salient roles in parasite–host interactions have been highlighted. Here, we analyze EVs from the rodent parasite Nippostrongylus brasiliensis, which has been used as a model for human hookworm infection. N. brasiliensis EVs (Nb-EVs) are actively internalized by mouse gut organoids, indicating a role in driving parasitism. We used proteomics and RNA-Seq to profile the molecular composition of Nb-EVs. We identified 81 proteins, including proteins frequently present in exosomes (like tetraspanin, enolase, 14-3-3 protein, and heat shock proteins), and 27 sperm-coating protein-like extracellular proteins. RNA-Seq analysis revealed 52 miRNA species, many of which putatively map to mouse genes involved in regulation of inflammation. To determine whether GI nematode EVs had immunomodulatory properties, we assessed their potential to suppress GI inflammation in a mouse model of inducible chemical colitis. EVs from N. brasiliensis but not those from the whipworm Trichuris muris or control vesicles from grapes protected against colitic inflammation in the gut of mice that received a single intraperitoneal injection of EVs. Key cytokines associated with colitic pathology (IL-6, IL-1β, IFNγ, and IL-17a) were significantly suppressed in colon tissues from EV-treated mice. By contrast, high levels of the anti-inflammatory cytokine IL-10 were detected in Nb-EV-treated mice. Proteins and miRNAs contained within helminth EVs hold great potential application in development of drugs to treat helminth infections as well as chronic non-infectious diseases resulting from a dysregulated immune system, such as IBD.

胃肠道（Gastrointestinal, GI）寄生虫，尤其是钩虫，已演化出对宿主极低的致病性，从而得以建立慢性感染。这一过程通过构建免疫调节微环境得以实现。事实上，钩虫是极强的炎症抑制因子，已被应用于治疗炎症性肠病（inflammatory bowel disease, IBD）和乳糜泻的临床试验中。自近期首次报道蠕虫（helminths，即蠕虫）分泌细胞外囊泡（extracellular vesicles, EVs）以来，不同蠕虫来源的类外泌体细胞外囊泡已得到系统表征，其在寄生虫-宿主互作中的关键作用也受到广泛关注。本研究针对啮齿类寄生虫巴西圆线虫（Nippostrongylus brasiliensis，该物种常作为人类钩虫感染的研究模型）的细胞外囊泡展开分析。巴西圆线虫来源的细胞外囊泡（Nb-EVs）可被小鼠肠道类器官主动摄取，提示其在寄生虫寄生过程中发挥功能。本研究通过蛋白质组学和RNA测序（RNA-Seq）技术对Nb-EVs的分子组成进行了全景式分析，最终鉴定得到81种蛋白质，其中包含外泌体常见组分（如四次跨膜蛋白、烯醇化酶、14-3-3蛋白以及热休克蛋白），另有27种精子包被蛋白样胞外蛋白。RNA测序分析共检测到52种microRNA（miRNA），其中多数推测靶向参与炎症调控的小鼠基因。为明确胃肠道线虫来源的细胞外囊泡是否具有免疫调节活性，本研究在诱导型化学性结肠炎小鼠模型中评估了其抑制胃肠道炎症的潜力。研究发现，仅巴西圆线虫来源的细胞外囊泡（而非鼠鞭虫Trichuris muris来源的囊泡或葡萄来源的对照囊泡）可在单次腹腔注射后，保护小鼠免受肠道结肠炎炎症损伤。经囊泡处理的小鼠结肠组织中，与结肠炎病理相关的关键细胞因子（IL-6、IL-1β、IFN-γ及IL-17A）的表达水平均显著下调；与之相反，经Nb-EVs处理的小鼠体内可检测到高水平的抗炎细胞因子IL-10。蠕虫来源细胞外囊泡所包含的蛋白质与microRNA，在开发治疗蠕虫感染以及免疫失调引发的慢性非传染性疾病（如IBD）的药物方面具有巨大应用前景。