抗人活化血小板单克隆抗体SZ－51嵌合Fab片段在大肠杆菌中的表达

CONSTRUCTION AND EXPRESSION IN E. COLI OFCHIMERIC FAB FRAGMENT OF ANTI-HUMANACTIVATED PLATELETS MONOCLONAL ANTIBODYSZ-51

单克隆抗体介导的导向显像与导向溶栓是对血栓栓塞性疾病诊断与治疗的有效手段之一。为了降低鼠源性单抗对人体的免疫原性，我们应用基因重组技术将抗人活化血小板α颗粒膜蛋白ＧＭＰ－１４０单克隆抗体ＳＺ－５１可变区基因片段与人免疫球蛋白γ１重链ＣＨ１和轻链恒区基因进行拼接，构建噬菌体质粒（ｐＨＥＮ１－５１Ｆａｂ／Ｈｕ），并导入大肠杆菌ＨＢ２１５１中进行表达。表达的嵌合抗体Ｆａｂ片段为可溶性，经Ｗｅｓｔｅｒｎｂｌｏｔ证实能特异地与ＧＭＰ－１４０呈结合反应。经ＥＬＩＳＡ定量测定，表达上清液中的抗体含量为２００μｇ／Ｌ。

n order to reduce the immunogenecity of murinemonoclonal antibody (mAb) to human beings , the cD-NA encoding the variable regions of mouse mAb SZ-51 , which is specific against α-granule membrane pro-tein (GMP) 140 on activated human platelets, was at-tached to the Ck and CH1 (γ1 isotype) constant do-mains of human immunoglobulin by means of recombi-nant DNA technique. The phagemid construct pHEN1-51Fab/Hu was obtained and introduced into non-sup-pressor E. Coli strain HB2151 for expression of solublechimeric Fab fragments. The chimeric SZ-51 Fab frag-ments were proved to bind specifically to GMP-140 bywestern blot. The antibody concentration in the cul-ture supernatant was 200μg/L measured by enzyme-linked immunosorbent assay (ELISA).