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Business Potential for Agricultural Biotechnology Products
natural EPO without glycosylation. Amino acid sequence analysis showed that the EPO is indeed
human EPO, not porcine EPO. Generally the TG pig strain has a relatively high RBC count
and hematocrit value. However, it shows a moderate growth rate when compared to a normal pig.
The average birth rate is eight and a half piglets per delivery (six of them are usually transgenic).
Human EPO production in the milk was confirmed after both the first and second delivery. The
possible application of this transgenic pig for other uses beseides EPO production, especially the
use of male TG pigs, must be considered. There is a possibility that these TG animals consider
the human EPO as part of themselves (since a certain amount of hEPO already exists in their
plasma but not in that of ordinary pigs). The TG males could be used as animal test subjects for
the antigenicity of hEPO gene therapy targeting vectors or the purity of recombinant EPO protein
itself. Also, since transgenic pigs show general symptoms of erythrocytosis, they can be
used as the model animal for this disease (Shibata et al., 2003). Since Saerome, NLRI has
produced a number of transgenic pig lines harboring human genes encoding therapeutic proteins
such as human blood coagulation factor VIII or tissue plasminogen activator (t-PA) under regulatory
control of mammary-gland-specific promoters (whey acidic protein or beta-casein
promoter) or urinary-bladder-specific uroplakin II (UPII) promoter (unpublished data). Several
individuals of the transgenic pig line were tested for human protein concentration in their milk or
urine. NLRI recently reported the successful creation of transgenic pigs that produce the recombinant
human tissue plasminogen activator in their urine (unpublished data). While these pigs
are still too young to produce offspring and their recombinant protein products are in the process
of analysis, NLRI has already shortened the timelines for the production of transgenic pigs. Still,
for the transgenic animal producing human protein, the human EPO transgenic pig line is the
only one that is close to mass production. NLRI is now pursuing the goal of bringing the product
into manufacturing and clinical trials in cooperation with a new Korean bioventure company,
PMG Biopharming.
In addition to NLRI, there are number of leading research forces in the research and
pharmaceutical industry.
Transgenic Cattle
Production of Human Lactoferrin in the Milk of the Transgenic Animal (Boram) (Source of
information: 30–31 October 1998. The 2nd Korea-Japan Joint Seminar on Animal Biotechnology.
Kim S.J. et al. The production of recombinant proteins and transgenic animals. Korea Research
Institute of Bioscience and Biotechnology (KRIBB), Tajeon, Korea. Journal of Biochemistry
(Tokyo) 1999; 126(2): 320–325.)
The Korea Research Institute of Bioscience and Biotechnology (KRIBB) announced that a
transgenic cow, “Boram,” that can express human lactoferrin (hLF) in its milk, was generated
utilizing microinjection. hLF is a pivotal protein abundant in mother’s milk that confers antibacterial
functions on babies and elevates their immune responses (Kim et al.,1999). The complete
gene encoding the hLF was isolated from a cosmid library and its structure was characterized.
The expression level of hLF protein in a transgenic animal ranged from 0.1 to 34 g per
ml. Milk contains a significant number of substances having peptide characteristics that are
known to possess biological activity; however, bovine milk doesn’t contain LF. Thus bovine
milk containing hLF will be highly effective in maintaining children’s health. KRIBB has four
domestic patents and five pending patents regarding the hLF transgenic cow. KRIBB has announced
that they are at the stage of mass-breeding transgenic cows and are in the process of
technology transfer with Doosan Co., a major Korean food and beverage company.
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