多反应性单克隆抗体的免疫生化分析

IMMUNOCHEMICAL STUDY ON POLYSPECIFIC MONOCLONAL ANTIBODY

探讨多反应性抗体的交叉反应机制是免疫学基础理论研究的重要课题。我们曾研制了一批多反应性单克隆抗体，其中抗体ＸＹ１２不仅能够与中间纤维蛋白结合，而且还与ＤＮＡ发生反应。本文采用免疫生化的方法，产生、纯化并分析了抗体ＸＹ１２的Ｆａｂ片段。ＥＬＩＳＡ和放射免疫印迹结果表明，这些Ｆａｂ片段仍具有完整抗体的多反应性。竞争性抑制实验显示，一定量的波形蛋白能够有效地抑制抗体ＸＹ１２与ＤＮＡ的结合。这些结果提示抗体ＸＹ１２的对两种抗原的反应确实都发生在抗体与抗原的结合区域而非抗体的其它部位。

To study the cross-reacting machnisms of polyspecific antibodies is an important subject in the field of im-munology.We have produced a set of polyspecific McAbs.Among them antibody XY12 bound to both intermediatefilament protein vimentin and nucleic acids.Here we described the production,purification and characterization ofthe Fab fragments derived from XY12.ELISA and radioimmunoassay showed that these Fab retained the samespecificities as the intact antibody XY12. A competitive inhibition experiment displayed that vimentin was sufficientto inhibit the reaction of antibody XY12 with DNA. Our results suggest that the cross reaction of XY12 really oc-curs in the antigen binding region rather than other portions of the antibody.