Expression of active recombinant human α1-antitrypsin in transgenic rabbits

A DNA construct containing the human α1-antitrypsin gene including 1.5 and 4 kb of 5′ and 3′ flanking sequences, was microinjected into the pronucleus of rabbit embryos. The recombinant human protein was (a) expressed in the blood circulation of F0 and F1 transgenic rabbits at an average concentration of 1 mg ml −1, (b) shown to be fully active and (c) shown to be separable from its rabbit counterpart. Transgenic rabbits might represent a novel source of human proteins of therapeutic interest.