For the first time ever, honeybees were orally ‚vaccinated’ with a genetically engineered product that was later detected in the bloodsucking Varroa mite. This product is a DNA-plasmid that is normally used for man, horses, swine and also for fish. The inventor of this innovative DNA-vaccination system for bees is Matthias Giese, PhD, who launches his own Institute for Molecular Vaccines (IMV) in Heidelberg/Germany starting in 2010.
DNA-vaccines are a new generation of modern vaccines, consisting of a circular plasmid structure, coding for a specific antigen, without any toxic or dangerous elements of the pathogen. The first DNA-vaccines are already used on animals.
This innovative bee ‘vaccine’ is mixed into a standard nutrient solution based on sugar. The test DNA-plasmid pVAX-EGFP-SV40 is coding for a so-called reporter gen and expresses a green fluorescent protein. This test-protein can be detected later on by fluorescence microscopy or by an immunoblot system via antibodies. The remarkable observation is that the expression of EGFP is driven by a SV40 promotor, normally used for humans and mammals. The insect-specific promoter also works as expected.
Bees affected by Varroa mites were fed with the test-DNA-plasmid over several days. Afterwards, both the bees and the mites were investigated for the presence of EGFP. The results are very clear: Both the bees and mites were found to be positive for EGFP, indicating that the mites had absorbed the EGFP via bloodsucking.
This technology now opens the way for a successful oral application of a specific DNA-plasmid as anti-Varroa agent. The DNA-plasmid is able to code for a key stimulus to enhance the bee’s immune system fighting against Varroa or a toxic substance specific to the mite only. A highly specific siRNA coded by this DNA-plasmid is also possible. Last but not least, this DNA-plasmid can be delivered as an aerosol spray directly into the brood comb. This product is safe, nonhazardous for the bees and is not transmitted to the environment during pollination.
The inventor of this innovative DNA-vaccination system for bees is Matthias Giese, PhD. He began these studies in 2004 and launched the program as IMV in 2007, filing for grant money from the German Federal Ministry of Food, Agriculture and Consumer Protection. Giese had worked in several head functions for more than 15 years in international pharmaceutical companies when he joined the Fraunhofer Institute for Cell Therapy and Immunology in 2006 as Head of Vaccine Development. In 2009 he left Fraunhofer in order to launch his own Institute for Molecular Vaccines (IMV) in Heidelberg/Germany starting in 2010. Giese is a leading expert for DNA-vaccines, especially for therapeutical vaccines. He has previously published a patent on the first therapeutical DNA-vaccines against a persitent viral infection in horses.
From an economical point of view, the bee is the third most important livestock animal of man, next to swine and cattle because of its worldwide pollination activities in agriculture.
Where have all the bees gone? There are lots of important troubles affecting the health of bees. Pesticide contamination, fungal diseases such as Nosema ceranea, the rigors of travel in trucks from one crop area to another and electric smog are thought to influence the bee’s life. Between the end of 2006 through the beginning of 2007, American beekeepers reported losses of 30% to 90% of their honeybee hives, a phenomenon referred to as ‘colony collapse disorder’ (CCD) by experts. In other countries, e.g. in Germany, the reported losses for 2008 are of 40% to 50%. Similar losses are also reported in other European countries. Pollination is a critical element in agriculture since honey bees pollinate more than 130 crops in the United States and add $15 billion in crop value annually.
Maybe the most important contributing factor to CCD, and the most powerful enemy of honeybees, is an overabundance of parasites such as the bloodsucking Varroa mites. A Varroa mite attaches to the body of the bee and sucks its hemolymph. This process spreads RNA viruses, such as the deformed wing virus (DWV), to the bee. A mite infestation will lead to the death of a bee colony. The Varroa mite is the parasite with the most pronounced economic impact on the beekeeping industry. Therefore, the development of biologically safe and efficient anti-Varroa-products is absolutely necessary. Compounding the problem, Varroa mites around the globe have grown resistant to chemical substances.