Liu M K, Pearson T W
Department of Biochemistry and Microbiology, University of Victoria, B.C., Canada.
Parasitology. 1987 Oct;95 ( Pt 2):277-90. doi: 10.1017/s0031182000057735.
A double antibody sandwich ELISA technique has been developed for detection of antigens of African trypanosomes present in the sera of infected mammals. The assay uses a high titre, high affinity rabbit antiserum made to purified membranes of procyclic trypanosomes as "capture" reagent and a mixture of three biotin-labelled trypanosome-specific monoclonal antibodies as detecting reagent. The monoclonal antibodies were chosen on the basis of their specificity for surface membrane antigens of Trypanosoma brucei spp., the relative abundance and solubility of their specific antigen in aqueous solvents (including serum), and the fact that each monoclonal antibody binds to distinct epitopes on the same antigen molecule. Thus, antigen capture from serum and subsequent detection was achieved using as little as 10 ng/ml of whole trypanosome lysate, or the equivalent of 5000 trypanosomes/ml when solubilized material was added to normal serum in an artificial system. Using the optimized assay, antigen was detected in the sera of trypanosome-infected mice as early as 2 days after infection with T. b. rhodesiense. The results indicate that the assay allows detection of low concentrations of specific membrane antigens of T. brucei spp. of African trypanosomes and thus may have immunodiagnostic utility.
已开发出一种双抗体夹心酶联免疫吸附测定（ELISA）技术，用于检测感染哺乳动物血清中存在的非洲锥虫抗原。该测定法使用针对前循环锥虫纯化膜制备的高滴度、高亲和力兔抗血清作为“捕获”试剂，并使用三种生物素标记的锥虫特异性单克隆抗体混合物作为检测试剂。这些单克隆抗体是根据它们对布氏锥虫属表面膜抗原的特异性、其特异性抗原在水性溶剂（包括血清）中的相对丰度和溶解性，以及每种单克隆抗体与同一抗原分子上不同表位结合的事实来选择的。因此，在人工系统中，当将溶解的物质添加到正常血清中时，使用低至10 ng/ml的全锥虫裂解物或相当于每毫升5000个锥虫，即可从血清中捕获抗原并进行后续检测。使用优化后的测定法，早在感染罗德西亚布氏锥虫2天后，就在锥虫感染小鼠的血清中检测到了抗原。结果表明，该测定法能够检测非洲锥虫布氏锥虫属低浓度的特异性膜抗原，因此可能具有免疫诊断用途。
