Heterologous Introns Enhanced Expression of Human Lactoferrin cDNA in Mouse Mammary Epithelial Cells

  • Kim, Sun-Jung (Bioresources Research Group, Genetic Engineering Research Institute, Korea Institute of Science and Technology) ;
  • Yu, Dae-Yeul (Bioresources Research Group, Genetic Engineering Research Institute, Korea Institute of Science and Technology) ;
  • Lee, Ko-Woon (Bioresources Research Group, Genetic Engineering Research Institute, Korea Institute of Science and Technology) ;
  • Cho, Yong-Yeon (Lab. of Animal Resources, National Institute of Safety Research) ;
  • Lee, Chul-Sang (Bioresources Research Group, Genetic Engineering Research Institute, Korea Institute of Science and Technology) ;
  • Han, Yong-Mahn (Bioresources Research Group, Genetic Engineering Research Institute, Korea Institute of Science and Technology) ;
  • Lee, Kyung-Kwang (Bioresources Research Group, Genetic Engineering Research Institute, Korea Institute of Science and Technology)
  • Received : 0
  • Accepted : 0
  • Published : 0

Abstract

The expression of a recombinant human lactoferrin is reported in mouse HC11 mammary epithelial cells. Expression of human lactoferrin (hLF) was achieved by placing its cDNA under the control of the bovine ${\beta}$-casein gene. To improve the hLF expression level in a cell culture system, two artificial introns were also introduced to construct expression vectors. One intron was a hybrid-splice signal consisting of bovine ${\beta}$-casein intron 1 and rabbit ${\beta}$-globin intron II. The other intron was a DNA fragment spanning intron 8 of the bovine ${\beta}$-casein gene. The hybrid intron moderately elevated hLF expression, whereas intron 8 alone did not express any detectable amount of hLF as judged by Northem and Western blot analyses. When the two introns were used together they contributed to a synergistic elevation of hLF expression. These data indicate that artificial introns on both sides of the hLF cDNA were necessary to increase expression of cDNA.

Keywords

Bovine ${\beta}$-casein promoter;human lactoferrin;hybrid intron