【关键词】 单克隆抗体(mAb);胰岛素;重组人胰岛素原类似物
Development of monoclonal antibodies against insulin by immunization with recombinant human proinsulin analog
【Abstract】 Objective To prepare monoclonal antibody (mAb) against insulinMethods Spleen cells from BALB/c mice immunized with recombinant human proinsulin analog were fused with SP2/0 myeloma cells by using hybridoma techniques.Results Seven hybridomas secreting mAb against insulin were established and designated A, B, C, D, E, F and G. The subclass of the seven mAb was IgM, IgM, IgM, IgG2b, IgG1, IgG1 and IgG1 respectively. The seven mAb could specifically react with insulin derived from human, cattle or pig in sandwich ELISA. The specific reaction of each mAb with recombinant human proinsulin analog was confermed by immunoblotting assay, only one stained protein band appeared on the transferred film.Conclusion The seven mAb are immunological specific to insulin derived from human, cattle or swine, and are available to the detection and purification of insulin.
【Key words】 monoclonal antibody (mAb); insulin; recombinant human proinsulin analog
胰岛素是具有重要生理功能的一种多肽类激素,在治疗糖尿病方面具有重要用途。胰岛素抗体是胰岛素测定和纯化所必需的免疫学试剂。为此进行了本研究。
1 材料与方法
1.1 菌种、质粒和细胞 大肠杆菌JM109、小鼠骨髓瘤SP2/0细胞系、含有λ噬菌体PRPL串联启动子的人胰岛素原类似物(BKRA)基因表达质粒pBV- BKRA由本课题组构建和保存[1]。
1.2 免疫血清的制备 收集大肠杆菌JM109培养物,离心沉淀菌体,用超声波破碎,加福氏佐剂乳化后,经皮下注射免疫兔,制备JM109免疫血清。
1.3 重组人胰岛素原类似物的制备 用pBV-
BKRA转化JM109[1〗。取单个菌落,30℃培养14h,以20%接种在含卡那霉素(Kan)的新鲜LB培养液中,42℃振荡培养4h,高速离心沉淀菌体。参照文献[2〗分离包涵体,用二硝基苯磺酸钠处理[3〗后作为BALB/c小鼠免疫抗原。
1.4 免疫鼠 将制备的重组人胰岛素原类似物与等量福氏完全佐剂混合乳化,经腹腔注射免疫6周龄的BALB/c小鼠,20mg/(次·只),免疫2次,间隔2周。在细胞融合前3~4天, 加强免疫1次。
1.5 细胞融合 参照文献[4〗,用免疫的BALB/c小鼠制备脾细胞,与小鼠骨髓瘤细胞SP2/0融合。
1.6 杂交瘤细胞的筛选与克隆化 采用间接抑制ELISA方法。用重组人胰岛素原类似物包被ELISA反应板,10%的JM109免疫血清封闭,加入杂交瘤细胞培养上清液与之反应,再与辣根过氧化物酶(HRP)标记的兔抗鼠IgG反应,显色。从两次检测均为阳性的杂交瘤细胞孔中选取7个阳性孔,用有限稀释法进行克隆化。
1.7 单克隆抗体的制备 将单克隆化的阳性杂交瘤细胞扩大培养,按5×106/只的细胞量注射于7~10天前预先腹腔注射无菌液状石蜡的BALB/c小鼠腹腔内,诱生腹水,制备mAb。
1.8 单克隆抗体的效价 用重组人胰岛素原类似物包被ELISA反应板,以常规间接ELISA分别测定各单克隆化的杂交瘤细胞培养上清液和诱生腹水中的mAb效价。
1.9 单克隆抗体的鉴定
1.9.1 亚类 将浓缩10倍以上的杂交瘤细胞培养上清液或杂交瘤细胞诱生腹水,用抗鼠Ig亚类血清(Sigma产品),以琼脂双扩散试验鉴定mAb的亚类。