UNASSIGNED: In this study, we attempted to develop a new type of therapy using value-added probiotics-producing antiparasitic RNA interference (RNAi) molecules against a vital hookworm (Ancylostoma sp.) enzyme, astacin-like metalloprotease Ac-MTP-1. A new gut delivery RNAi vector was designed to produce double-stranded RNA (dsRNA) against the target to be delivered by feeding with a probiotic Lactococcus lactis that when administered in endemic areas can potentially be used to control the spread of infection by interrupting the life cycle of hookworm.
UNASSIGNED: The engineered probiotics colonizing the gut, when consumed by the parasite released the dsRNA that which knocked down the target by RNAi interfering with their moulting and tissue migration. The initial penetration of the larvae into the gut lining was reduced by 70%, followed by a reduction of up to 50% in migration to the critical organs. The damage caused to the liver (30%-40%) and the kidneys (50%-60%) by the hookworm in mouse models as quantitated by enzymes released in the blood was totally reversed when the worms were pre fed with the engineered L. lactis before the parasite challenge.
UNASSIGNED: We believe that this is the first demonstrated knockdown of a target gene in hookworms using probiotics genetically engineered to stimulate RNAi (RNAi food), administered through the oral route. This novel method of parasite control when extended to other hookworms, A. duodenalis and A. ceylanicum can augment the efficacy of the existing anthelminthics if combined with them.
■在这项研究中,我们尝试开发一种新型疗法,使用产生增值益生菌的抗寄生虫RNA干扰(RNAi)分子来对抗重要的钩虫(Ancylostomasp.)酶,astacin样金属蛋白酶Ac-MTP-1。设计了一种新的肠道递送RNAi载体,以通过饲喂益生菌乳酸乳球菌来产生针对靶标的双链RNA(dsRNA),该乳酸乳球菌在流行地区施用时,可以潜在地通过中断来控制感染的传播钩虫的生命周期。
■工程益生菌定植于肠道,当被寄生虫消耗时,会释放dsRNA,该dsRNA通过RNAi干扰靶标的蜕皮和组织迁移来击倒靶标。幼虫进入肠壁的初始渗透减少了70%,其次是迁移到关键器官的减少高达50%。通过血液中释放的酶定量测定的小鼠模型中的钩虫对肝脏(30%-40%)和肾脏(50%-60%)的损害在寄生虫挑战之前用工程化乳酸乳球菌预先喂养蠕虫时完全逆转。
■我们认为这是首次证明使用基因工程益生菌刺激RNAi(RNAi食品)在钩虫中击倒靶基因,通过口服途径给药。当扩展到其他钩虫时,这种新的寄生虫控制方法,A.daudenalis和ceylanicum可以增强现有驱虫药的功效。