The synthesis of a recombinant protein in milk of transgenic mice

• Published in: Livestock production science Vol. 36; no. 1; pp. 35 - 38
• Main Authors: Stinnakre, Marie-Georges, Devinoy, Eve, Thépot, Dominique, Chêne, Nicole, Bayat-Samardi, Mahasti, Grabowski, Henri, Houdebine, Louis-Marie
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 1993; Elsevier
• Subjects: Life Sciences; Milk; Recombinant protein; Transgenic mice; Transgenic mice; Recombinant protein; Milk
• ISSN: 0301-6226; 1872-6070
• DOI: 10.1016/0301-6226(93)90135-5

Micro-organisms and lower euraryotes can synthesize large amounts of recombinant proteins but some of these molecules are not properly processed. Animal cells have to be used in some cases to obtain correct glycosylation, folding, etc. Milk of transgenic animals is considered as an excellent source of recombinant proteins. Mice are currently being used to evaluate the efficiency of gene constructs to be transferred in larger animals. It is generally considered that mice provide insufficient amount of milk to be the source of recombinant proteins. In the present paper it is shown that the isolated mammary gland from lactating mice isolated from their offsprings for one day released milk spontaneously when kept on ice for 2 to 18 hours. Essentially all the milk was released in this way. This procedure was applied to transgenic mice harboring the human growth hormone gene fused to the promoter of the rabbit whey acidic protein gene. The transgenic mice secreted the hormone at the concentration of 10 mg/ml (mean value). The hormone released with milk after incubation of the mammary gland on ice was undergraded and it kept its prolactin like activity. The method described in the present paper can therefore be used to prepare a few hundred milligrammes of recombinant proteins for biochemical or pharmaceutical studies. It may provide interesting information on the properties of recombinant proteins and thus be a first step towards the preparation of these molecules using farm animals.