黑素瘤相关抗原D4(MAGE-D4)多克隆抗体的制备和应用

Preparation and application of melanoma-associated antigen D4 polyclonal antibody

目的制备兔抗人黑素瘤相关抗原D4(MAGE-D4)多克隆抗体,鉴定其免疫学特性,并进行初步应用。方法对构建的p MAL-C2/MAGE-D4重组质粒进行原核表达及纯化,获得MBP/MAGE-D4融合蛋白,并以此蛋白免疫新西兰兔制备多克隆抗体。抗体经蛋白A凝胶柱亲和层析法纯化后,通过SDS-PAGE检测其纯度;间接ELISA、Western blot法检测抗体的效价及特异性;免疫组织化学染色法检测肺癌组织中MAGE-D4的表达及定位。结果获得纯度较高的抗MAGE-D4多克隆抗体,ELISA检测抗体的效价为1∶256 000,Western blot法分析显示MAGE-D4多克隆抗体可特异性识别MAGE-D4重组蛋白,免疫组织化学结果表明,该抗体能识别肺癌组织中的内源性MAGE-D4蛋白,表达的阳性率为69.6%(17/23)。结论制备的MAGE-D4多克隆抗体具有较高的特异性和灵敏度。

Objective To prepare the rabbit polyclonal antibody recognizing human melanoma-associated antigen D4（ MAGE-D4）,and identify its immune characteristics for preliminary application. Methods MBP/MAGE-D4 fusion protein was expressed from p MAL-C2/MAGE-D4 recombinant plasmid constructed in the previous work. Then the purified MBP/MAGE-D4 protein was used to immunize the New Zealand white rabbits for generating polyclonal antibody. Subsequently,the anti-MAGE-D4 antibody was purified with protein A affinity chromatograph and identified by SDS-PAGE. The titer and specificity of the antibody were further detected by indirect ELISA and Western blotting,respectively. MAGE-D4 expression and localization of lung cancer tissues were analyzed by immunohistochemical staining. Results MAGE-D4 polyclonal antibody with high purity was obtained. Its titer was about 1∶256 000. Western blot analysis demonstrated that the antibody could specifically react to the recombinant MAGE-D4 protein. Immunohistochemical staining showed that the antibody could recognize the endogenous MAGE-D4 protein in lung cancer tissues,and its positive rate was 69. 6%（ 17/23）. Conclusion The MAGE-D4 polyclonal antibody with high specificity and sensitivity has been successfully prepared.