Development of an indirect ELISA for detecting Toxoplasma gondii IgG antibodies based on a recombinant TgIMP1 protein

• Published in: PLoS neglected tropical diseases Vol. 18; no. 8; p. e0012421
• Main Authors: Dong, Hongjie, Zhang, Junmei, Wang, Qi, Shen, Yanmei, Zhou, Beibei, Dai, Lisha, Zhu, Wenju, Sun, Hang, Xie, Xiaoman, Xie, Huanhuan, Xu, Chao, Zhao, Guihua, Yin, Kun
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 14.08.2024; Public Library of Science (PLoS)
• Subjects: Analysis; Animals; Antibodies, Protozoan - blood; Antigens, Protozoan - genetics; Antigens, Protozoan - immunology; Biology and Life Sciences; Care and treatment; Diagnosis; Dosage and administration; Engineering and Technology; Enzyme-linked immunosorbent assay; Enzyme-Linked Immunosorbent Assay - methods; Escherichia coli - genetics; Humans; Immunoglobulin G; Immunoglobulin G - blood; Medicine and Health Sciences; Physical Sciences; Protozoan Proteins - genetics; Protozoan Proteins - immunology; Recombinant proteins; Recombinant Proteins - genetics; Recombinant Proteins - immunology; Research and Analysis Methods; Risk factors; Sensitivity and Specificity; Toxoplasma - genetics; Toxoplasma - immunology; Toxoplasmosis; Toxoplasmosis - diagnosis; Toxoplasmosis - immunology; Toxoplasmosis - parasitology; China
• ISSN: 1935-2735; 1935-2727; 1935-2735
• DOI: 10.1371/journal.pntd.0012421

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 OD 450nm 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.