El Ridi R, Salah M, Wagih A, William H, Tallima H, El Shafie M H, Abdel Khalek T, El Amir A, Abo Ammou F F, Motawi H
Zoology Department, Faculty of Science, Cairo University, Cairo 12613, Egypt.
Vet Parasitol. 2007 Nov 10;149(3-4):219-28. doi: 10.1016/j.vetpar.2007.08.024. Epub 2007 Sep 25.
Excretory-secretory products (ESP) products of ex vivo Fasciola gigantica adult worms were used for immunodiagnosis of sheep experimental infection with F. gigantica and natural infection with Fasciola spp. by enzyme-linked immunosorbent assay (ELISA) and Western blotting. Specific IgG antibody binding to native or denatured ESP was detected as early as 2 weeks after experimental sheep infection with 100 or 200 metacercariae. No specific IgG antibody binding was displayed by sera obtained from 192 sheep considered to be Fasciola- and other parasite-free by microscopic examination of bile and feces. Additionally, sera from 200 apparently Fasciola-free sheep, yet infected with other parasites, were all negative. The data, thus, indicated that ESP-based ELISA reached nearly 100% sensitivity and specificity in immunodiagnosis of sheep fasciolosis. As expected, the ESP molecules were immunogenic in sheep eliciting interleukin-12p40 mRNA response and considerable amounts of antibodies, which were able to bind to the surface of newly excysted juvenile worms as judged by membrane indirect immunofluorescence, and mediate their attrition via antibody-dependent cell-mediated cytotoxicity. The ESP-induced cellular and humoral immune responses were associated with a modest reduction in worm count, yet with a highly significant (P<0.0001) decrease in size of recovered worms, thus suggesting that ESP immunization might be a safe and cost-effective strategy for reducing transmission of the infection.
采用体外培养的巨片形吸虫成虫的排泄分泌产物（ESP），通过酶联免疫吸附测定（ELISA）和蛋白质印迹法，对绵羊大片吸虫实验感染和片形吸虫属自然感染进行免疫诊断。在实验绵羊感染100或200个囊蚴后2周，即可检测到与天然或变性ESP结合的特异性IgG抗体。通过对胆汁和粪便进行显微镜检查，从192只被认为无片形吸虫和其他寄生虫的绵羊获得的血清未显示特异性IgG抗体结合。此外，来自200只明显无片形吸虫但感染了其他寄生虫的绵羊的血清均为阴性。因此，这些数据表明基于ESP的ELISA在绵羊片形吸虫病免疫诊断中灵敏度和特异性接近100%。正如预期的那样，ESP分子在绵羊中具有免疫原性，可引发白细胞介素-12p40 mRNA反应和大量抗体，通过膜间接免疫荧光判断，这些抗体能够结合新脱囊的幼虫表面，并通过抗体依赖性细胞介导的细胞毒性介导其损耗。ESP诱导的细胞免疫和体液免疫反应与虫体数量适度减少相关，但回收虫体的大小显著（P<0.0001）减小，因此表明ESP免疫可能是一种安全且具有成本效益的减少感染传播的策略。
