从噬菌体抗体库筛选获得中和性人源抗甲型肝炎病毒Fab抗体

目的 研究人源抗甲型肝炎病毒基因工程抗体，为预防甲型肝炎病毒感染提供有效的方法。方法 采用噬菌体表面展示技术，从一名甲型肝炎恢复期病人的抗凝血中分离淋巴细胞，提取总ＲＮＡ逆转录后，用一组人ＩｇＧ Ｆａｂ特异性引物扩增。结果 克隆和表达了８株人源抗甲型肝炎病毒抗体Ｆａｂ段基因，经ＥＬＩＳＡ检测为特异性人抗甲型肝炎病毒Ｆａｂ段抗体。结论 该８株人源抗甲型肝炎病毒Ｆａｂ抗体都能与具有中和活性的鼠抗甲型肝炎病毒单克隆抗体产生竞争抑制反应，选其中的２株做体外中和实验，证明都有中和甲型肝炎病毒的活性。

Human Fab antibodies derived from phage display library neutralize hepatitis A virus in vitro

Objective Development of recombinant human monoclonal antibody to hepatitis A virus as a emergent measure for prevention of hepatitis A virus infection. Methods Human neutralizing monoclonal antibody Fab fragments to HAV have been developed by using phage display technique. The heavy and light chains of human IgG Fab genes were amplified from a HAV patient in convalescent stage. The combinatorial phage antibody library was established by inserting both heavy and light chains of Fab genes into phagemid vector pComb3 and followed by help phage infection after 4 rounds of panning with purified HAV as coated antigen. Results The human Fab fragments to HAV were selected and expressed in bacteria. Conclusion The specific binding of Fab antibodies to HAV were demonstrated by their reaction with HAV antigen in ELISA. These results provide the basis for further development of a neutralizing recombinant human whole IgG molecule and hold promise for future use in the prophylaxis of HAV infection.