Sengupta K, Das P, Johnson T M, Chaudhuri P P, Das D, Nair G B
National Institute of Cholera and Enteric Diseases P-33, Beliaghata, Calcutta, India.
J Eukaryot Microbiol. 1993 Nov-Dec;40(6):722-6. doi: 10.1111/j.1550-7408.1993.tb04465.x.
Six monoclonal antibodies (MAbs) were produced against a highly immunogenic fraction derived by the chromatographic separation of the soluble preparation of axenic Entamoeba histolytica (strain NIH:200) trophozoites. Isotype characterization of the six MAbs revealed that four belonged to the IgM class and one each to the IgG1 and the IgG2a subclasses. The immunoreactivity patterns and the specificity of the MAbs with homologous and heterologous antigens were analyzed by the enzyme-linked immunotransfer blot technique and by the enzyme-linked immunosorbent assay. The MAbs reacted intensely with isolates of E. histolytica (strain NIH:200 as well as a local isolate MX1) but showed no reactivity with Entamoeba coli, Iodamoeba butschlii, Endolimax nana, Entamoeba hartmanni, free-living amoeba (Acanthamoeba harticolus) and other enteric parasites. Using the IgG1 MAb as a detecting antibody, a polyclonal-monoclonal antibody-based enzyme-linked immunosorbent assay was developed for the detection of E. histolytica antigens in stool samples of infected patients. The detection limit of the assay was 8 ng of amoebic antigen. This test was found to be specific and sensitive and yielded 100% positive results in cases with amoebiasis but did not react with controls included in the evaluation. The MAb-based enzyme-linked immunosorbent assay developed in this study will be an important test for the diagnosis of E. histolytica in the feces of infected humans; however, the limitation of the test is the inability to discriminate the pathogenic status of the amoeba detected in the stool.
针对通过无菌培养的溶组织内阿米巴（菌株NIH:200）滋养体可溶性制剂的色谱分离获得的高免疫原性组分，制备了六种单克隆抗体（MAb）。对这六种单克隆抗体的亚型进行鉴定，结果显示四种属于IgM类，一种属于IgG1亚类，一种属于IgG2a亚类。通过酶联免疫转移印迹技术和酶联免疫吸附测定法分析了单克隆抗体与同源和异源抗原的免疫反应模式及特异性。这些单克隆抗体与溶组织内阿米巴分离株（菌株NIH:200以及本地分离株MX1）强烈反应，但与结肠内阿米巴、布氏嗜碘阿米巴、微小内蜒阿米巴、哈氏内阿米巴、自由生活阿米巴（棘阿米巴）及其他肠道寄生虫无反应。以IgG1单克隆抗体作为检测抗体，开发了一种基于多克隆 - 单克隆抗体的酶联免疫吸附测定法，用于检测感染患者粪便样本中的溶组织内阿米巴抗原。该测定法的检测限为8 ng阿米巴抗原。发现该试验具有特异性和敏感性，在阿米巴病患者中产生100%阳性结果，但与评估中纳入的对照无反应。本研究中开发的基于单克隆抗体的酶联免疫吸附测定法将是诊断人类粪便中溶组织内阿米巴的一项重要试验；然而，该试验的局限性在于无法区分粪便中检测到的阿米巴的致病状态。
