抗血吸虫成虫表膜抗原单克隆抗体检测循环抗原及/或免疫复合物的实验研究

DETECTION OF CIRCULATING ANTIGEN AND/OR ANTIGEN-ANTIBODY COMPLEX BY USING McAb AGAINST SURFACE MEMBRANE ANTIGEN OF ADULT SCHISTOSOMA JAPONICUM

本文报告用单克隆抗体检测血吸虫感染兔血清中循环抗原及/或免疫复合物的实验结果.以血吸虫成虫盐水浸液抗原ACSE免疫BALB/c小鼠,取其脾脏与SP2/0骨髓瘤细胞融合获得抗成虫表膜的单克隆抗体8SE_4。此抗体经DE_(52)柱层析提纯后制成HRP-8SE_4结合物.血清样本与HRP-8SE_4作用后加入PEG(mw·6000)沉淀免疫复合物,然后加入底物OPD显色,于492nm读数,OD值即反映血循环中抗原及/或免疫复合物的量。实验结果表明5只重感染兔(接种尾蚴15O0～2000条)于感染后6wk可见OD值明显升高,达到感染前的1.9～4.5倍。5只轻感染兔接种尾蚴10～500条亦于感染6wk后OD值明显上升,至感染后8wk达高峰,此后至11wk剖杀时仍维持在较高水平.5轻感染兔检虫数为4～326条,未见虫荷与检测结果有明显相关。本实验结果提示感染兔血清中有循环表膜抗原及/或其复合物存在。至于检测该抗原能否用于考核治疗效果,有待进一步研究。

In the present paper, the results of detecting circulating antigen and/or antigen-anti-body complexes by McAb against surface membrane antigen of adult Schistosama japo-nicum were reported. The McAb, coded as 8SE4, was prepared by fusion of SP2/0 myeloma cslls with spleen cells of the BALB/c mice immunized with the saline extract of adult S, japonicum. The 8SE4- directed antigen was proved to be located on the surface of the adult worm. After being purified by a DE52 column, 8SE4 was labelled with HRP and the conjugate (HRP-8SE4) was used in the test. For testing, the serum sample was first incubated with HRP-8SE4, then PEG (mw. 6 000) was added to precipitate the antigen-antibody complex. Upon centrifugation, OPD was added to the precipitate. Results were read by ELISA reader at 492nm. The OD value was found to be proportional to the amount of circulating antigen and/or antigen-antibody complexes. Results from 5 heavily infected (1 500-2 000 cercariae) rabbits showed that the OD values were raised signifi-cantly at the 6th week post infection, being 1.9-4.5 times higher than those before ins faction. The OD values of the 5 rabbits each lightly injected with 10-500 cercariae were also markedly raised 6 weeks post infection and reached the peak at the 8th week, then maintained in high levels until 11th week post infection. The worm burden of the 5 lightly infected rabbits were 4-326. No obvious correlations between OD values and worm loads were observed. The results suggested the existence of surface membrane-related an-ligen and/or antigen-antibody complexes in the circulation of infected rabbits.