對C型肝炎病毒NS3抗原具有特異性的人類單株重組抗體片段之產生與其特性分析

C型肝炎病毒(HCV)是目前主要引起慢性肝炎的病源之一，可能與肝硬化及肝癌的發生有關。HCV的非結構性蛋白NS3是一種highly conserved且具有protease及helicase活性的多功能蛋白質，在HCV的複製過程扮演一個非常重要的角色。因此對於治療慢性C型肝炎，NS3應該是一個很重要的目標。單株抗體已普遍的應用於治療、診斷及基礎研究中，為了更深入地了解HCV NS3的可能致病機轉及其單株抗體的可能應用，嗜菌體表現系統提供了一種方法用以產生大量的對NS3抗原具有特異性的單株抗體。在本研究中我們獲得了兩個含有重鏈結合kappa輕鏈或重鏈結合lambda輕鏈的抗體基因庫，分別具有4.65x10*4和2.5x10*5的大小。經過4次針對於NS3的篩選過程後，隨機挑選出的菌株利用限制酵素分析，同時具有kappa輕鏈及重鏈的菌株比例由46.6%增加到93.3%，同時具有lambda輕鏈及重鏈的菌株比例由71.4%增加到100%。更進一步由西方點墨分析法偵測到50kD大小的蛋白質，顯示輕鏈及重鏈都有被表現出來並構成正確的Fab抗體片段結構。初步的ELISA結果顯示，4個菌株可能對NS3抗原具有特異性。DNA序列的分析結果顯示4個菌株中有2個是完全相同但不同於另外2個相同的菌株，而且重鏈都是屬於VH4這一族。我們所獲得的菌株是否的確對於NS3具有特異性，仍需要更進一步的證實。經由DNA序列的分析比較，將可得知人類抗HCV NS3抗體基因中的使用情形。而這些抗HCV NS3單株抗體應有助於C型肝炎的治療以及闡明NS3在病毒感染過程中扮演的角色。另外，本實驗所建構的人類抗體基因庫亦可更進一步地應用於篩選對其他不同抗原具有特異性的單株抗體。

關鍵字

C型肝炎病毒；非結構性蛋白NS3 ；抗體基因庫；嗜菌體表現系統

並列摘要

Hepatitis C virus (HCV) is one of the major pathogens of chronic hepatitis, which may lead to liver cirrhosis and hepatoma. Nonstructural protein 3 (NS3) of HCV is a highly conserved and multi-functional protein with protease and helicase activity, which plays an important role in HCV replication. To further study HCV NS3 and the possible applications of monoclonal antibody, phage display system offers an alternative method for the generation of large numbers of anti-NS3 mono-specific antibody molecules. In the present study, two phage display antibody libraries were established by combining PCR products of heavy chain genes with those of either kappa or lambda light chain genes, resulting in 4.65x10*4 and 2.5x10*5 clones in size, respectively. After 4th panning against the NS3 of HCV, the results of restriction analysis on randomly selected clones showed that both heavy and light chain gene inserts increased from 46.6% to 93.3% (kappa library) and 71.4% to 100% (lambda library), respectively. Furthermore, the detection of a 50 kD protein molecule using western blotting technique suggested the heavy and light chain polypeptides have been expressed and associated into the correct configuration. The preliminary ELISA data suggested that 4 clones may be specific for NS3, but not for BSA. DNA sequences of 4 clones indicated that 2 clones are identical but different from the other 2 identical clones. Whether or not these Fab fragments are specific for NS3 antigen remains to be determined. Taken together, our data suggested phage display system could offer an efficient way in the generation of NS3-specific clones.

並列關鍵字

HCV ； NS3 ； combinatorial library technique ； phage display system

參考文獻

Abrams, P. G., Rossio, J. L., Stevenson, H. C., and Foon, K. A. Optimal strategies for developing human-human monoclonal antibodies. Methods Enzymol 121: 107-119, 1986 Barbas, C.

F. III, Kang, A. S., Lerner, R. A., and Benkovic, S. J. Assembly of combinatorial antibody libraries on phage surfaces: the gene III site. Proc Natl Sci USA 88: 7978-7982, 1991(A) Barbas, C.

F. III, and Lerner, R. A. Combinatorial immunoglobulin libraries on the surface of phage (phabs): rapid selection of antigen-specific Fabs. Methods 2: 119-124, 1991(B) Behrens, S.-E., Tomei, L., and Francesco, R.

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對C型肝炎病毒NS3抗原具有特異性的人類單株重組抗體片段之產生與其特性分析

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