Glossary

ADCC:

ADCC (antibody dependent cellular cytotoxicity) is defined as the reaction of natural killer cells (NK) on antibody-labeled cells. ADCC is provided by the help of the Fc-receptors which are able to recognize the Fc-domains of antibodies. The affinity of the Fc-domain to Fc-receptors can be modified by the glyco-engineering of antibodies. The cells identified by the NK-cells are destroyed by the killer cells. This immunological response is an important efficacy principle by the application of therapeutic antibodies in the cancer therapy.

Left: Antibodies (red) bind with their variable regions to a certain epitope of a tumour cell (grey). The constant region of the antibody binds to the receptor of killer cells. The killer cells destroy the antibody-labeled killer cells and combat the cancer. Right: Antibodies with glycoengineered sugar structures (blue) lead to a higher binding affinity of the constant region of the antibodies to the receptors of killer cells. Therefore significantly smaller amounts of antibodies are needed to combat the cancer leading to new therapeutic possibilities.

Biopharmaceuticals:

Biopharmaceuticals are pharmaceuticals which are produced by means of modern biotechnological production systems in place of chemical synthesis. To this group of therapeutics belong, above all, recombinant, diagnostic and therapeutic proteins like monoclonal antibodies, human serum proteins, human growth hormones, enzymes and vaccines.

Double-Knock-out:

Simultaneously elimination of two genes in the genome of an organism by help of homological recombination. By means of homological recombination, greenovation was able to generate a stable moss cell line where the α1,3-fucosyl- and ß1,2-xylosysltransferase are eliminated simultaneously.
Because of that, glycoproteins can be produced in this doublel-KO cell line which lack certain plant-specific sugar residues whose immunogenic potential could be proved. Due to the missing ß1,6-fucose residue, this special glycan structure is able to increase the efficacy of therapeutic antibodies by the rise of the ADDC.

Glykan:

see Glycoproteins

Glycoproteins:

A large part of the human proteins in the human body is glycosylated, by being connected with complex sugar molecules. Only in recent years, have we become aware of the essential influence of these sugar residues on the protein function. Many proteins receive their specific efficacy or function only by means of the attached sugar molecule. Many illnesses, including carcinogenesis and diseases of the immune system are connected with certain sugar molecules.

Glyco-engineering:

Glyco-engineering is defined as the well-directed modification of the genetic coding of the sugar structure of therapeutic proteins. Only the correct sugar structure (glycosylation) gives the produced protein its desired high specialization. Thus, its pharmacological efficacy is improved and simultaneously increased by a multiple. The applied dose and thus also the cost of treatment is lowered significantly. The better the understanding of the glycosylation, the more precisely the biopharmaceuticals can be optimized by glyco-engineering, efficacies can be increased and side effects minimized. A well-directed modification of the sugar molecules opens a wide application field in the treatment of infection, cancer und auto-immune diseases.

Antibodies possess specific glycan structures which influence their function. By genetic deletion of certain enzymes, the glycan structure of antibodies can be optimized.

Mosses:

From a botanical point of view the mosses can be grouped in a class called Bryophyta (Bryo = moss). However, evolution-historically there are three independent groups which have each the status of a subclass: hornworts, liverworts and mosses. The mosses distinguish themselves by robustness and stability under different conditions of cultivation.
The lifecycle of mosses begins as haploid, photoautotrophic gametophytes which carries the relatively simply built, diploid and heterotrophic sporophyts. After the germinating at first the green and fibrous protonema constitutes which can be cultivated under special growth conditions in photobioreactors. The nowadays best characterized moss is the moss Physcomitrella patens which is also used for greenovation® bryotechnology.

Physcomitrella patens.

Photobioreactor:

The photobioreactor enables the cultivation of photoautotrophic organisms in glass tubes. Besides, cultivation parameters like the density of the moss, pH value, agitation speed, CO2-gassing and light exposure can be regulated.

Manufacturing of therapeutic proteins in photobioreactors. The produced glycoproteins are secreted from the moss tissue into the medium.