THE DEVELOPMENT OF NEW DAIAGNOSTICS AND CHEMOTHERAPEUTICS AGAINST ECHINOCOCCAL INFECTION

泡状棘球绦虫病(AE)是一种潜在的致命的人畜共患病，如果不及早诊断以提供根治治疗。因此，识别和表征独特的分子和途径应该有助于开发有效的化疗措施。我们用患者血清筛选了多房棘球绦虫(Em)基因表达文库，并鉴定了6个新的抗原编码基因。其中，肌动蛋白调节蛋白(EmAMP)和过氧化还蛋白(EmPrx)在分子水平上得到了鉴定。1)AMP揭示了与其他已报道的肌动蛋白结合蛋白相同的结构基序。在大肠杆菌中表达的重组EmAMP对聚合的F-肌动蛋白具有切割活性，验证了其生化功能。我们还对39例AB患者和97例其他寄生虫感染患者进行了酶联免疫吸附试验(EL ISA)，以评估其抗原性。酶联免疫吸附试验结果表明，EmAmp为…更多的一种主要免疫显性抗原，被AE患者血清识别。总之，我们认为来自多房棘球绦虫的EmAMP可能是一个很好的靶点来开发新的诊断和治疗包虫病的药物。2)Prx在48和169位氨基酸具有两个活性半胱氨酸残基，这两个氨基酸在所有真核Prx中是完全保守的。重组EmPrx蛋白通过Fenton反应保护超螺旋DNA免受Nicking.此外，EmPrx在与大肠杆菌硫氧还蛋白/硫氧还蛋白还原酶体系结合时，催化降解内过氧物。我们研究了EmPrx在其发育过程中的免疫定位。多克隆抗体可使EmPrx结合到成体的六头节和五头节膜、原头节表面和排泄管上。我们认为EmPrx作为一种重要的抗氧化酶，在保护寄生虫免受宿主防御反应中产生的活性氧的影响中起着重要的作用，并且EmPrx也可能成为开发新的化疗药物的良好靶点。较少

Alveolar echinococcosis (AE) is a potentially-fatal zoonotic disease if not diagnosed early enough to provide curative treatment. Therefore, identification and characterization of unique molecules and pathways should help in the development of effective chemotherapeutic measures. We screened an Echinococcus multilocularis (Em) cDNA expression library with a patient serum, and identified 6 novel antigen encoding genes previously not reported. Among them, actin-modulator protein (EmAMP) and peroxiredoxin (EmPrx) was characterized at molecular level in this study. 1)AMP revealed common structural motifs shared by other actin-binding proteins previously reported. An Escherichia coli-expressed recombinant EmAMP showed severing activity toward the polymerized F-actin, verifying its biochemical function. We also evaluated its antigenicity in an enzyme-linked immunosorbent assay (ELISA) using 39 AB patients and 97 patients with other parasitic infections. Results of ELISA showed that EmAMP is … More one of major immuno-dominant antigens recognized by the AE patient sera. Altogether, we propose that EmAMP from E. multilocularis could be a good target to develop new diagnostics as well as chemotherapeutics against echinococcal infection. 2)Prx possesses two active cysteine residues at amino acids 48 and 169 that are totally conserved among all eukaryotic Prx. Recombinant EmPrx protein protected supercoiled plasmid DNA from nicking by Fenton reaction. Furthermore, EmPrx catalysed degradation of endoperoxides when coupled with an E. coli thioredoxin/ thioredoxin reductase system. We examined the immunolocalization of EmPrx during its development. Polyclonal antibody raised EmPrx bound to the oncosphera and oncoshperal membrane, the surface of protoscolex, and the excretory canal in adults. We propose that EmPrx plays a role in the protection of the parasite from reactive oxygen species generated in host defense responses as an important antioxidant enzyme, and EmPrx also could be a good target to develop new chemotherapeutics. Less