title: Chicken hypersensitive site-4 insulator increases human serum albumin expression in bovine mammary epithelial cells modified with phiC31 integrase.
abstract: Achieving high expression levels of recombinant human serum albumin (HSA) for purification is a solution for the large amount of plasma-derived HSA needed in therapeutic applications. Here, we employed phiC31 integrase system and chicken hypersensitive site-4 (cHS4) insulators to construct a HSA expression vector for high-level HSA expression. The phiC31 integrase system mediated efficient transgene integration in bovine mammary epithelial cells (bMECs). A preferred pseudo attP site, which had 38 % identity with the 39 bp wild-type attP sequence, was detected in six out of 55 bMEC colonies. Addition of the cHS4 insulator to the phiC31 integrase system resulted in 8-20-fold increases of HSA expression compared with that of using integrase alone. Moreover, the reverse-oriented cHS4 insulator in the phiC31 integrase system provided the optimal level of HSA expression in bMECs.
authors.affiliation: College of Veterinary Medicine, Northwest A&F University, Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Yangling 712100, Shaanxi, People's Republic of China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Luo
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.forename: Qingqing
authors.initials: Q
authors.lastname: Liu
authors.forename: Liming
authors.initials: L
authors.lastname: Zheng
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Wang
authors.forename: Jianmin
authors.initials: J
authors.lastname: Su
authors.forename: Guangdong
authors.initials: G
authors.lastname: Hu
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001709:Biotechnology / Q000379:methods*; D002417:Cattle; D018929:Cell Culture Techniques / Q000379:methods; D002645:Chickens; D004847:Epithelial Cells / Q000378:metabolism*; D015870:Gene Expression; D005822:Genetic Vectors; D006801:Humans; D038101:Insulator Elements; D019426:Integrases / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000096:biosynthesis; D012709:Serum Albumin / Q000096:biosynthesis*; D000075462:Serum Albumin, Human; D013678:Technology, Pharmaceutical / Q000379:methods*
chemical_list: C422455:ALB protein, human; D011994:Recombinant Proteins; D012709:Serum Albumin; D019426:Integrases; D000075462:Serum Albumin, Human