High Level Expression of Recombinant Human Antithrombin in the Mammary Gland of Rabbits by Adenoviral Vectors Infection

Expression of recombinant pharmaceutical proteins in the mammalian mammary gland is of great interest for the medical industry. This study was designed to express recombinant human antithrombin (rhAT) in the mammary gland of rabbits by adenovirus vectors infection. Replication-defective adenovirus encoding human antithrombin complementary DNA (cDNA) was constructed and directly infused into the mammary gland of rabbits via the teat canal. The milk serum was collected from the infected mammary gland 48 h post-infection and subjected to Western blot analysis, Enzyme-linked immunosorbent assay (ELISA), and antithrombotic activity assay. In this way, the target protein was verified, and a high expression level of rhAT up to 4.8 g/L was obtained, and antithrombotic activity of the rhAT was not different than that of a standard human antithrombin protein (p > 0.05). Compared to previous attempts to produce human antithrombin in the mammary gland of transgenic animals or fractionation the plasma of blood donors,...