近日，比利时研究人员通过研究表示，借助改造宿主自身携带的有益细菌，可以抑制昏睡症罪魁祸首锥体虫的生长，从而达到遏制昏睡症传播的目的。
昏睡症，学名为非洲锥虫病，是一种致命性疾病，在非洲一些地区相当流行。锥体虫寄生于采采蝇，经由后者叮咬进入人体，导致发病。患病初期，人体会出现发烧、头疼、关节疼痛和发痒的症状；这一病症进入第二阶段、锥体虫侵入人体神经系统后，人体会出现反应迟钝、嗜睡的症状。如果不经治疗，患者有生命危险。
针对昏睡症的传统治疗方案出现于50多年前。患者接受治疗时极其痛苦，同时需要承担其他副作用，大约5%至20%接受治疗的患者因注射药物后导致的并发症死亡。
因此，医学界一直在寻找治疗这一病症的其他可选方案。比利时安特卫普热带医学研究所一个团队把研究焦点集中在如何防止人体染病，而非如何治疗。相关成果论文刊登于期刊《微生物细胞工厂》Microbial Cell Factories上 。
英国广播公司2月15日援引成果论文报道，采采蝇与人类类似，会携带一些有益细菌。研究人员发现，一种采采蝇携带的共生菌或许有能力向锥体虫发起攻击。
借助改变这种共生菌的基因，研究人员得以使它释放出一种纳米抗体，杀死锥体虫或者阻止这种寄生虫的生长。
伦敦大学卫生与热带医学院学者戴维·霍恩评价：“这是一项具有发展前景的观念。”（生物谷Bioon.com）
doi:10.1186/1475-2859-11-23
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Expression and extracellular release of a functional anti-trypanosome Nanobody(R) in Sodalis glossinidius, a bacterial symbiont of the tsetse fly
Linda De Vooght, Guy Caljon, Benoit Stijlemans, Patrick De Beatselier, Marc Coosemans and Jan Van Den Abbeele
Background Sodalis glossinidius, a gram-negative bacterial endosymbiont of the tsetse fly, has been proposed as a potential in vivo drug delivery vehicle to control trypanosome parasite development in the fly, an approach known as paratransgenesis. Despite this interest of S. glossinidius as a paratransgenic platform organism in tsetse flies, few potential effector molecules have been identified so far and to date none of these molecules have been successfully expressed in this bacterium. Results In this study, S. glossinidius was transformed to express a single domain antibody, (Nanobody(R)) Nb_An33, that efficiently targets conserved cryptic epitopes of the variant surface glycoprotein (VSG) of the parasite Trypanosoma brucei. Next, we analyzed the capability of two predicted secretion signals to direct the extracellular delivery of significant levels of active Nb_An33. We show that the pelB leader peptide was successful in directing the export of fully functional Nb_An33 to the periplasm of S. glossinidius resulting in significant levels of extracellular release. Finally, S. glossinidius expressing pelBNb_An33 exhibited no significant reduction in terms of fitness, determined by in vitro growth kinetics, compared to the wild-type strain. Conclusions These data are the first demonstration of the expression and extracellular release of functional trypanosome-interfering Nanobodies(R) in S. glossinidius. Furthermore, Sodalis strains that efficiently released the effector protein were not affected in their growth, suggesting that they may be competitive with endogenous microbiota in the midgut environment of the tsetse fly. Collectively, these data reinforce the notion for the potential of S. glossinidius to be developed into a paratransgenic platform organism.
