知识与财富的链接
培养细胞实验表明,亮氨酸拉链通过改善内含肽(intein)的蛋白质剪接效率,提高双载体转B区缺失型凝血因子Ⅷ(BDD-FⅧ)基因细胞剪接FⅧ蛋白的分泌量和活性.本文从C57BL/6小鼠门静脉注射含亮氨酸拉链和Ssp DnaB内含肽融合的BDD-FⅧ的重链和轻链基因双表达载体,48 h后,检测到血浆的重链分泌量和FⅧ活性分别为(298±67)μg/L和(1.15±0.29)U/mL,明显高于不含亮氨酸拉链的双载体转BDD-FⅧ基因对照小鼠((179±59)μg/L和(0.58±0.19)U/mL).结果表明,亮氨酸拉链通过改善蛋白质反式剪接,提高基于蛋白质剪接的双载体转BDD-FⅧ基因小鼠血浆的凝血活性,为进一步双腺相关病毒(AAV)载体转BDD-FⅧ基因的甲型血友病基因治疗研究提供了依据.
We previously demonstrated that leucine zippers fused to intein could increase secretion of spliced B-domain-deleted coagulation factor Ⅷ (BDD-FⅧ) protein and activity by dual-vector based BDD-FⅧ gene transfected cell in vitro through improving protein trans-splicing. In this study, a pair of plasmid vectors expressing human BDD-FⅧ heavy and light chain fused with lucine zipper and split Ssp DnaB intein was co-injected into C57BL/6 mice via the portal vein. Fourty-eight hours post-injection, the level of heavy chain and FⅧ coagulation activity in collected plasma were determined and shown as (298±67) μg/L and (1.15±0.29) U/ml respectively, greater than that of control mice injected with both vectors without leucine zippers ((179±59) μg/L and (0.58±0.19) U/ml). It demonstrated that leucine zippers fused intein could increase FⅧ coagulation activity in plasma of mice with intein-based dual-vector BDD-FⅧ gene delivery through improved protein trans-splicing. It provided evidence for ongoing hemophilia A gene therapy using dual-AAV vecors.