人─鼠抗人小细胞肺癌嵌合重链基因在小鼠骨髓瘤细胞中的表达

采用聚合酶链反应（ＰＣＲ）方法获得小鼠抗人小细胞肺癌单克隆抗体的变区基因（ｃＤＮＡ），构建成含人──鼠抗人小细胞肺癌嵌合重链基因质粒（ｐＳＶ＿２△Ｈｇｐｔ２Ｆ＿７Ｖ＿ＨＨｕγ＿３）ＤＮＡ通过电脉冲介导基因转移的方法，转染小鼠骨髓瘤细胞Ｊ５５８Ｌ，并经选择培养基筛选出含有构建质粒基因的克隆，进一步按ＥＬＩＳＡ方法测定细胞表面和培养上清液中嵌合重链抗体的表达效率，最终选出表达抗体效率较高的单克隆细胞株为５Ｃ＿２，１２Ｂ＿９，２９Ｃ＿６。Ｎｏｒｔｈｅｒｎｂｌｏｔ方法检测证明，阳性克隆细胞总ＲＮＡ经电泳后在１８Ｓ附近处与鼠抗人小细胞肺癌单抗的重链变区ｃＤＮＡ探针有明显的阳性杂交带出现。细胞抽提蛋白经ＳＤＳ──ＰＡＧＥ电泳分离显示在正常人ＩｇＧ重链分子相当的位置有一清晰条带出现，分子量约为５８ＫＤ，免疫印迹方法同样检测出此条带特异他与兔抗人ＩｇＧ（重链特异）抗体反应，证实人──鼠抗人小细胞肺癌嵌合重链基因在小鼠骨髓癌细胞中表达成功。

EXPRESSION OF CHIMERIC HEAVYCHAIN ANTINOD SPECIFICFOR HUNAN SMALL CELL LUNG CANCER IN MOUSE MYELO-MA CELL

ecombinant plasmid containing a chimeric gene enceding the humam C_H domain and themouse V_H domain with specificity for human small cell lung cancer was constructed and intro-duced into a mouse myeloma cell line(J558L) by electroportion. Three positive clones were ob-tained and characterized by ELISA. Expression of the chimeric polypeptide chains was detectedthrough an immunoreaction by Western blot and appeared as a single positive band.Followinganalytical SDS-PAGE under nonreducing condition, the immunostaining band as assessed fromthe relative mobility was 58KD,which is identical with the heavy chain of human lgG,Northernblot hybridization analysis has shown a strong signal corresponding to mRNA of the V_H domainspecific for human small cell lung cancer.