高亲和力抗角蛋白人抗体的基因工程制备

Genetical Engineering of Humanized Anti-keratin Antibodies with High Affinity

目的 制备亲和力高、性能良好的人源性抗角蛋白抗体。方法 以人表皮角蛋白为抗原从噬菌体抗体库中克隆特异性抗角蛋白抗体,采用基因随机点突变和链替换(chain-shuffing)技术对所获抗体进行亲和力成熟,并对其生物学性能进行一系列鉴定。结果 经过筛选半合成抗体库和天然抗体库,成功获得了4株能与角蛋白特异性结合的人源性抗角蛋白IgG或IgM抗体;对抗体基因的随机突变未产生预期的性能改进,又选择其中活性最好的一株IgG抗体,通过轻链替换和重链替换使抗体亲和力得到了有效提高,达到8×1010/M的理想水平。结论 用基因工程的方法可以制备高质量的人源性抗角蛋白抗体。

Objective To produce humanized anti-keratin antibodies with high affinity. Methods Panning of phage antibody libraries against human epidermal keratin was conducted to select specific antibodies. Random mutation method and chain-shuffling technique for the gene of the antibodies were employed to improve antibody affinity. The binding activity, specificity and affinity of the obtained antibodies were de-termined and analyzed. Results Four clones of either IgG or IgM anti-keratin antibodies were seleeted from semisynthetic or natural antibody libraries. One of them was seleeted to undergo affinity maturation. Random mutation method for the gene did not result in any improvement in antibody affinity. By chain-shuffling technique, however, affinity level was markedly increased and an antibody with affinity of 8×1010/M was isolated. Conclusion It is feasible to generate humanized antikeratin antibodies using genetical engineering technique.