(per) Two scientists at ETH Zurich, Peter H. Seeberger and Daniel Werz, have perhaps laid a new foundation for a new anthrax vaccine. This was reported last week at the on-line portal "Informationsdienst Wissenschaft" (1). In the lab they were able to reconstruct a tetrasaccharide that is only found on the surface of spores of the anthrax pathogen. Of special importance here is the terminal sugar unit, so-called anthrose. This seems to be specific to the bacterium bacillus anthracis and could enable the body's immune system to selectively recognise foreign matter and fight it. Over the past year scientists have succeeded in explaining the structure of this tetrasaccharide.

Sugar variant with potential

Scientists at the ETH Institute of Organic Chemistry and Chemical Biology have now built on this knowledge. With a new, particularly effective, synthesis Seeberger and Werz were able to produce the anthrose unit. In addition they attached a type of molecular "hook" to the tetrasaccharide. In a later step a transport protein, necessary for a successful immunisation, can be coupled to this. The scientists laid out their entire synthesis process in such a flexible way that different variations of the sugar molecule are easily accessible..

Spores and bacteria of Bacillus anthracis: Dreaded biological weapon. (Picture: WHO)

At the moment the two ETH scientists are carrying out immunological studies on tetrasaccharides. Diverse saccaride derivatives are also being tested in order to examine their value as highly specific anthrax vaccines.

Great potential of oligosaccharides

Some time ago already scientists recognised the potential of saccharides in the development of new vaccines. Until now, however, these saccharides were difficult to get hold of. This situation has suddenly changed with the development of an automaton that can synthesise oligosaccharides in a solid form, according to an article by ETH Professor Peter H. Seeberger published in "Nature Reviews" (2). Such oligosaccharides could be employed, for instance, to produce a malaria vaccine. Initial trials have delivered promising results (3).