Shandong Institute of Parasitic Diseases, Shandong First Medical University & Shandong Academy of Medical Sciences, Jining, People's Republic of China.
Digestive Disease Hospital of Shandong First Medical University, Shandong First Medical University & Shandong Academy of Medical Sciences, Jining, People's Republic of China.
PLoS Negl Trop Dis. 2024 Aug 14;18(8):e0012421. doi: 10.1371/journal.pntd.0012421. eCollection 2024 Aug.
Toxoplasma gondii (T. gondii) is widely spread around the world, which can cause serious harm to immunosuppressed patients. Currently, the commercial test kits are poor at assessing T. gondii infection and vaccine effectiveness, making an urgent need to exploit effective enzyme-linked immunosorbent assay with great performance to compensate for this deficiency. Here, the TgIMP1 recombinant protein was expressed in E. coli BL(21) cells. The TgIMP1 was purified with affinity chromatography and the reactivity was retained with anti-TgIMP1 antibodies. The TgIMP1 was then used to develop an indirect ELISA (IMP1-iELISA) and the reaction conditions of IMP1-iELISA were optimized. As a result, the cut-off value was determined to be 0.2833 by analyzing the OD450nm values of forty T. gondii-negative sera. The coefficient of variation of 6 T. gondii-positive sera within and between runs were both less than 10%. The IMP1-iELISA was non-cross-reactive with the sera of cytomegalovirus, herpes virus, rubella virus, Cryptosporidium spp., Theileria spp., Neospora spp. and Plasmodium spp.. Furthermore, the sensitivity and specificity of IMP1-iELISA were 98.9% and 96.7%, respectively, based on testing 150 serum samples. The results suggest that this IMP1-iELISA is specific, sensitive, repeatable and can be applied to the detection of T. gondii infections in the medical and health industries.
刚地弓形虫（Toxoplasma gondii）广泛分布于世界各地，可对免疫抑制患者造成严重危害。目前，商业检测试剂盒在评估弓形虫感染和疫苗效果方面能力较差，因此迫切需要开发具有优异性能的有效酶联免疫吸附试验来弥补这一不足。本研究在大肠杆菌 BL（21）细胞中表达了 TgIMP1 重组蛋白。利用亲和层析对 TgIMP1 进行纯化，并用抗 TgIMP1 抗体保留其反应性。然后，将 TgIMP1 用于开发间接 ELISA（IMP1-iELISA），并优化了 IMP1-iELISA 的反应条件。结果表明，通过分析 40 份阴性弓形虫血清的 OD450nm 值，确定了 0.2833 为截断值。6 份阳性血清在批内和批间的变异系数均小于 10%。IMP1-iELISA 与巨细胞病毒、疱疹病毒、风疹病毒、隐孢子虫、泰勒虫、新孢子虫和疟原虫血清无交叉反应性。此外，基于对 150 份血清样本的检测，IMP1-iELISA 的灵敏度和特异性分别为 98.9%和 96.7%。研究结果表明，该 IMP1-iELISA 特异性、灵敏性、重复性良好，可应用于医学和卫生行业的弓形虫感染检测。
