GENET archive


5-Animals: GE silkworms spin human collagen protein

genet-news mailing list

-------------------------------- GENET-news --------------------------------

TITLE:  Silkworms spin medicinal gold
SOURCE: Genome News Network, USA, by Kate Dalke
DATE:   Jan 10, 2003

------------------ archive: ------------------

Silkworms spin medicinal gold

Scientists in Japan have genetically modified silkworms to secrete the 
human protein collagen. In their cocoons, the insects produced both silk 
and collagen, which is used to generate artificial skin and cartilage and 
in cosmetic surgery to fill out lips and wrinkles. The technology has 
potential to optimize the bulk production of collagen for medical uses. 

This is the first time insects have been used to produce a medically 
important protein, says Florian Wurm, a biotechnology professor at the 
Swiss Federal Institute of Technology in Lausanne, Switzerland. Wurm wrote 
a commentary accompanying the study in Nature Biotechnology.

Currently, most medical collagen comes from cow tissue, which can cause 
allergic reactions in some patients. Limited quantities of collagen - and 
other human proteins - are grown in animal cells.

Japan Science and Technology Corporation in Hiroshima led the project. 
Seeking an abundant source of patient-friendly collagen, the researchers 
turned to an industrious insect. They inserted a human gene for collagen 
into silkworms. The protein was produced in the silk glands and secreted 
into cocoons, where the collagen was extracted.

"The production is extremely fast and it appears that the [extraction] 
technology is not complicated," says Wurm.

Silkworm production is a major industry in India, Japan, China and Europe, 
and these resources could be converted to manufacture collagen and other 
human proteins, the researchers say. They estimate that a facility with 1.5 
million silkworms could produce 5 kilograms of collagen per year, in 
addition to silk.

The technology is extremely "low-tech" in the sense that you don't need a 
molecular biologist to handle the day-to-day manufacturing, says Wurm.

Silkworms are larvae of the caterpillar, Bombyx mori, which has been bred 
for thousands of years for its production of precious fibers. The species 
is completely domesticated - no wild populations exist. After hatching from 
eggs, the worms snack on leaves from Mulberry trees and spin their silky 
cocoons in about three days.

Backers of the new biotechnology must still overcome some hurdles. Further 
research is necessary to determine whether insect cells produce the protein 
differently from human cells, and the collagen would need to be tested in 
clinical trials.

Tomita, M. et al. Transgenic silkworms produce recombinant human type III 
procollagen in cocoons. Nat Biotechnol 21, 52-56 (January 2003).


|                   GENET                     |
| European NGO Network on Genetic Engineering |
|                                             |
|             Hartmut MEYER (Mr)              |
|               Kleine Wiese 6                |
|           D - 38116 Braunschweig            |
|                 Germany                     |
|                                             |
| phone:  +49-531-5168746                     |
| fax:    +49-531-5168747                     |                      
| mobile: +49-162-1054755                     |
| email:                   |