www.checkbiotech.org ; www.raupp.info ; www.czu.cz

Tobacco plants can now produce vaccine against Lyme disease - a tick-borne
disease from the bacterium Borreliosis. Dr. Heribert Warzecha, from the
University of Wuerzburg, Germany, describes how his group was able to
accomplish this feat in the scientific journal Nature Biotechnology, January
2006 translated by Mark Hucko, Checkbiotech.

Scientists have already several times tried to generate plant-made
vaccines with the aid of genetic engineering. Generally it works since many
vaccines are protein-based, whose building code can be inserted into the
plant hereditary material as DNA. However, until now, enhanced plants have
produced only minute amounts of the desired substances.

In an innovative approach, Dr. Warzecha and his team built in the additional
hereditary information in the tobacco plant?s chloroplasts - not in the
cellular nucleus. Chloroplasts are small cellular organelles with their own
hereditary material, which help the plants to produce energy from sunlight.
The advantage: in one cell there are around one hundred chloroplasts in
comparison to only one nucleus. Thus, plants with transgenic chloroplasts
are more effective vaccine producers, in that the yield of a target protein
is much higher than those that target the nucleus.

Dr. Wuerzburg?s plants produce an OspA protein, which is also found on the
surface of the bacterium Borreliosis. However, OspA alone is not suitable as
a vaccine. To be effective it must be combined with fatty acids - and to Dr.
Wuerzburg?s fortunes his genetically modified plants were able to accomplish
this combination.

Experiments with mice showed that the tobacco vaccine has comparable
effectiveness with vaccines produced in conventional bacterial cultures.
However, it appears that people cannot take advantage of this protection
yet, since Borreliosis vaccines have not been granted public use by
regulatory officials.

[www.berlinonline.de]

------------------------------------------
Posted to Phorum via PhorumMail