Human nerve growth factor beta (hNGF-β): mammary gland specific expression and production in transgenic rabbits

Abstract Transgenic rabbits carrying gene constructs encoding human nerve growth factor beta (hNGF-β) cDNA were generated. Expression of hNGF-β mRNA was restricted to the mammary gland of lactating rabbits. Western Blot analysis revealed a polypeptide of 13.2 kDa in the milk of transgenic animals. hNGF-β was purified from the milk by a two-step chromatographic procedure. Electrospray mass spectroscopy analysis of purified hNGF-β depicted a molecular weight of 13 261 Da per subunit. The biological activity of the hNGF-β was tested using PC12W2 cells and cultures of dorsal root ganglion neurons from chicken embryos. Crude defatted milk from transgenic animals and purified hNGF-β demonstrated full biological activity when compared to commercial recombinant hNGF-β.