夹心免疫-PCR检测旋毛虫循环抗原的研究(英文)

目的建立以多抗为捕获抗体和单抗为检测抗体的夹心免疫-PCR检测旋毛虫循环抗原。方法利用杂交瘤技术制备抗旋毛虫单抗;旋毛虫抗原免疫家兔,分离纯化兔血清,制备兔抗旋毛虫多抗。多抗作为捕获抗体包被酶标板,单抗为检测抗体,选择适宜多抗和单抗浓度,建立夹心ELISA方法,再利用亲和素和生物素的高结合力连接起标记了生物素的抗体和DNA片段,将抗原抗体特异反应的免疫技术同无限扩增DNA片段的基因检测技术结合,利用PCR反应对DNA片段的扩增能力,提高检测灵敏度。结果制备了兔抗旋毛虫多抗,间接ELISA法筛选出与多种寄生虫抗原无交叉反应的单抗F4C6,夹心ELISA检测旋毛虫抗原最低浓度为0.05μg/ml,免疫PCR方法检测最低浓度为0.1ng/ml。结论首次建立夹心免疫-PCR检测旋毛虫抗原的方法,检测旋毛虫抗原的灵敏度高于传统ELISA方法104倍。

Highly sensitive Immuno-PCR assay for the detection of the circulating antigens in trichinellosis

A highly sensitive immuno-PCR assay based on sandwich ELISA and PCR was developed to detect the circulating antigen in trichinellosis. Antigens were purified from the muscle larvae of Trichinella spiralis, and the myeloma cells were fused with spenocytes immunized with T.spiralis antigens to product the specific monoclonal antibodies. Indirect ELISA was used to select the antibody-secreting hybrodoma cells. By this method of procedure, monoclonal antibody F4C6 against the T.spiralis ES antigen was obtained, which was used as the indicator antibody, while the rabbit polyclonal antibodies against T.spiralis were to be used as capturing antibodies. The plasmid Bluecript II KS was amplified by PCR with biotin-labeled primer M13-20, and thus the biotin-labeled DNA was obtained. Both the second antibody and DNA labeled with biotin were to be linked with 100 ng /ml avidin. The whole procedures of assay consisted of two steps, in which the circulating antigens were captured by monoclonal antibody through sandwich ELISA in the first step, and the DNA linked by monoclonal antibody was amplified by PCR in the second step. The sensitivity of this method was compared with that of the ELISA assay. It was found that the measuring ranges to detect the circulating antigens in trichinellosis were 50 pg/L to 0.005 pg/L for the immuno-PCR assay, and 5 μg/L to 0.05 μg/L for ELISA assay, the former was quite higher than that of the latter. It is evident that this method is highly sensitive for the detection of circulating antigens in trichinellosis.