抗人卵巢癌单域噬菌体抗体的表达

EXPRESSION OF SINGLE DOMAIN PHAGE ANTIBODY OF ANTI HUMAN OVARIAN CARCINOMA MONOCLONAL ANTIBODY

目的：制备抗人卵巢癌单克隆抗体ＣＯＣ１８３Ｂ２单域（重链可变区，ＶＨ）抗体，以用于卵巢癌放射免疫显像和导向治疗。方法：将已分离的ＶＨ基因克隆入噬菌粒表达载体ｐＦＵＷ８０中，将重组子转化琥珀突变抑制菌株ＸＬ１ＢＬｕｅ，经辅助噬菌体Ｍ１３Ｋ０７援救后包装成噬菌体颗粒，表达产物通过ＥＬＩＳＡ测定活性。结果：ＶＨ基因克隆入噬菌粒ｐＦＵＷ８０，双酶切鉴定见预期大小片段，表明克隆成功。表达产物经ＥＬＩＳＡ测定，待测值高出阴性对照２．５倍。结论：该抗人卵巢癌小分子单域抗体具有与相应卵巢癌抗原发生特异结合的能力，有望用于卵巢癌放射免疫显像和导向治疗。

Objective: To express the single domain (heavy chain variable region gene, V H) antibody of COC183 B 2 anti human ovarian carcinoma monoclonal antibody for radioimmuno imaging or target therapy. Methods: After a secondary amplification of the V H gene using a V H specific primer containing Xho Ⅰ and Spe Ⅰ sites, the products were digested with Xho Ⅰ and Spe Ⅰ and then inserted into phagemid pFUW80 in the corresponding sites. The recombinants were then introduced into E.coli XL1 BLue cells. After phagemid rescue using M13KO7 as a helper phage, the single domain antibody was expressed by phage display. The antigen binding activity of expressed product was determined by ELISA. Results: The recombinants were digested with Xho Ⅰ and Spe Ⅰ, and expected bands were identified. The value of expressed V H was 2.5 times more than that of negative control by ELISA. Conclusion: The V H gene of COC183 B 2 was successfully expressed in phagemid, and the phage antibody could interact specifically with ovarian carcinoma antigen.