Academician Li Ning of Agricultural University of China successfully developed a batch of human lactoferrin-transgenic cows recently. This indicates that the cultivation of new breeds of transgenic cows and animal bioreactor technology in China has reached the international advanced level and is a new national variety of genetically modified organisms to be implemented soon. Nurturing major projects has laid a solid foundation.
Academician Li Ning’s research group cooperated with Beijing Jipulin Biotech Co., Ltd. and other units. After more than seven years, successfully cultivating a batch of human lactoferrin transgenic cows. The recombinant human lactoferrin is the highest in the milk of these transgenic cows. Level, and has the same biological activity as the native protein, such as transport iron, antibacterial and so on.
Experts believe that the importance of successful development of these GM cows lies in the fact that they can not only produce recombinant human lactoferrin for large-scale application of large-scale applications, but also can be used for the development of new infant formulas, functional foods and pharmaceuticals, and they can exhibit high milk Protein content, anti-mastitis and other new features are good materials for breeding new varieties of cows.
Academician Li Ning is the chief scientist of the "973" major basic research project and director of the State Key Laboratory of Agricultural Biotechnology. He said that human lactoferrin is a natural protein in human breast milk and has important functions such as iron supplementation, antibacterial activity, anti-cancer activity, and enhancement of body immunity. It is an indispensable functional component for the growth and development of infants and young children. At present, most infant formula milk powders on the market are supplemented with lactoferrin purified from milk, but biological activity is far lower than that of human lactoferrin. Since human lactoferrin is mainly present in human breast milk, the source is very limited and it is difficult to mass-produce it using ordinary techniques.
According to reports, the rise of transgenic animal technology provides a reliable way to realize large-scale production of human lactoferrin and other valuable pharmaceutical health care proteins. Through gene transfer technology, human lactoferrin and other genes are introduced into dairy cow cells or embryos, and then transgenic cows are bred. Human lactoferrin and other proteins are present in the milk of these transgenic cows. These human lactoferrins can be used after purification. The development of new drugs or functional foods such as antibacterial, anti-cancer, iron supplements and blood supplements is the so-called transgenic animal bioreactor technology. Compared to the current mainstream mammalian cell culture biopharmaceutical technology, the transgenic animal bioreactor technology has the advantages of low cost, high efficiency, low energy consumption, and ability to produce complex proteins that the former cannot produce, and is the latest biopharmaceutical technology. At present, only a few developed countries, such as the United States, Britain, and the Netherlands, have mastered this technology. The scientific research results of the Li Ning Research Group show that China is very close to the international advanced level in this research field and will become an important field for breakthroughs in China's biopharmaceutical technology.
Academician Li Ning said that gastrointestinal health milk, formula milk, and anti-anemia drugs that are currently functioning as recombinant human lactoferrin have basically completed animal tests or preclinical tests. Clinical trials are underway and it is expected to be completed in 2 to 3 years. Clinical trials of the above products.
It is also known that the first batch of human lactoferrin-transgenic cows cultivated by the Li-Ning group has entered the lactation period. After testing, the total protein content in the transgenic milk has been increased by more than 10%. Meanwhile, milk containing human lactoferrin is effective in killing E. coli. The pathogenic bacteria of mastitis in dairy cows, such as Staphylococcus aureus, are expected to produce new breeds of transgenic cows with high milk protein content and resistance to mastitis.
At present, the research group has used the first generation of genetically modified dairy cows to breed a batch of transgenic bulls carrying the human lactoferrin gene, and is currently breeding transgenic cows through techniques such as artificial insemination for the large-scale production of milk containing human lactoferrin. , and a new breed of transgenic cows with high milk protein content and resistance to mastitis; at the same time, the transgenic cow has completed the environmental release test for the safety assessment of genetically modified organisms and entered the final stage of the safety evaluation of genetically modified organisms - a productive test once the production is completed. The sexual test and approval of national breeds will hopefully breed China's and the world's first new breed of genetically modified cows in three to five years to achieve a major breakthrough in the breeding of dairy cows in China. (Reporter: Li Jiangtao)