志贺毒素(Stx)与某些志贺氏菌属的食源性感染有关。和产志贺毒素的大肠杆菌(STEC),导致危及生命的溶血性尿毒综合征(HUS)。针对HUS的靶标特异性治疗剂目前在临床实践中不可用。在这里,我们报道了Gb3包被的牛乳外泌体(Gb3-mExo)作为多价志贺毒素中和剂的构建和体外表征,在药物递送和Stx与其受体Gb3之间的多价相互作用中利用牛奶外泌体(mExo)的天然优势。Gb3-mExo构建体通过将mExo与含有硬脂酸衍生的脂质尾的Gb3衍生物缀合来实现,这是通过有效的化学酶方法制备的。构建体能够有效中和Stx2的B亚基(Stx2B)与固定在板上或在模型细胞上表达的受体Gb3的结合。通过细胞毒性分析和溶血测定证明了构建体的一般安全性。除了在常规储存和处理条件下具有优异的稳定性外,该构建体还可以在胃肠道极端pH下保留其大部分中和效力,显示口服的潜力。考虑到mExo的天然可用性和优异的生物相容性,Gb3-mExo缀合物应证明是志贺毒素相关感染的实用预防和治疗。
Shiga toxin (Stx) is associated with foodborne infections of some Shigella spp. and Shiga toxin-producing Escherichia coli (STEC), leading to life-threatening hemolytic uremic syndrome (
HUS). Target-specific therapeutics against
HUS are currently unavailable in clinical practice. Herein, we reported the construction and in vitro characterization of Gb3-coated bovine milk exosomes (Gb3-mExo) as a multivalent Shiga toxin neutralizer, utilizing the natural advantages of milk exosomes (mExo) in drug delivery and multivalent interactions between Stx and its receptor Gb3. Gb3-mExo constructs were achieved by conjugating mExo with the Gb3 derivatives containing stearic acid-derived lipid tail, which was prepared through an efficient chemoenzymatic approach. The constructs were able to potently neutralize the binding of the B subunit of Stx2 (Stx2B) to receptor Gb3 immobilized on the plate or expressed on model cells. General safety of the constructs was evidenced by the cytotoxicity analysis and hemolysis assay. In addition to the excellent stability under conventional storage and handling conditions, the construct can also retain most of its neutralization potency under gastrointestinal pH extremes, showing the potential for oral administration. Considering the natural availability and excellent biocompatibility of mExo, Gb3-mExo conjugates should prove to be a practical prophylactic and therapeutic for the Shiga toxin-related infections.