从半合成噬菌体抗体库筛选基质金属蛋白酶—2人抗体

目的：从半合成噬菌抗体库中筛选抗金属蛋白酶－2（MMP－2）人源抗体。方法：将重组人MMP－2固相化，通过多轮“吸附－洗脱－扩增”从半合成抗体库筛选特异性抗体，用ELISA方法对所获克隆进行特异性分析及MMP－2中和活性。结果：经过4轮筛选，得到多个可与MMP－2结合的克隆，但这些克隆也可与其它无关抗原结合，选1个克隆AD20进行竞争抑制性ELISA分析，发现其与MMP－2的结合可被游离MMP－2特异性抑制，不被无关抗原抑制，而与无关抗原的结合不能被所测的任何游离抗原所抑制，进一步检测AD20可中和MMP－2的酶解活性，DNA序列测定证明其为人抗体。结论：从半合成抗体库中获得一株具有中和活性的抗MMP－2人抗体，该抗体对无关抗原显示的非特异性结合是由不同模式介导，属于多反应性。

Cloning of anti-MMP-2 human antibodies from semisynthetic phage antibody library

Objective:To clone human anti MMP 2 antibodies from semisynthetic phage antibody library.Methods:Panning of semisynthetic phage antibody library against recombinant human MMP 2 was conducted to select specific antibodies.The antigen binding characterastics were analyzed by ELISAs.Results:MMP 2 binding phage antibody clones were obtanied after four rounds of panning,but they all showed binding activity to unrelated ags tested.One clone,AD20,was chosen for further analysis by competitive ELISA.It was found that the binding of AD20 to MMP 2 could be inhibited only by free MMP 2 but not unrelated Ags,while the binding to other Ags could not be inhibited by Ags tested,including MMP 2.Neutralization test demonstrated that AD20 could neutralize the enzymatic activity of MMP 2.Conclusion:A neutralizing human antibody against MMP 2 was obtained from a semisynthetic phage antibody library,which shows bindings with unrelated Ags nonspecifically that may be caused by different binding modes,a phenomenon termed polyreactivity.