By Will Soutter
Scientists at the Biodesign Institute in Arizona State University have made use of DNA nanotechnology to produce a new group of synthetic vaccines. The team wanted to replicate the assembly of molecules in the body that initiate an immune response.
Synthetic Vaccine Complex (Credit: Biodesign Institute at Arizona State University)
Nanotechnology innovator Hao Yan is credited with the development of DNA nanostructures which could function as scaffolding material. The team at Arizona State University led by Yung Chang worked in collaboration with Hao Yan to test various shapes and sizes of DNA nanostructure for their ability to carry molecules that can trigger an immune response in the body.
The team created synthetic vaccine complexes resembling natural virus without the disease component. These were made of a protein for immune stimulation named streptavidin (STV) and a compound to boost immune response called an adjuvant (CpG oligo-deoxynucletides). These were then attached to DNA nanostructures of pyramid shape and branch-like structures. In order to establish that the nanostructures would be taken in by the target cells in the body, a light-emitting tracer molecule was attached to the DNA nanostructures. The team found that the nanostructures were safely ensconced in cells for a period of time long enough to generate an immune response. The team’s next challenge was to test the delivery of the vaccine to first responder cells in order to check for effective immune response. The experiment was carried out on mice wherein all variables were tested. There were thus three categories, viz. full vaccine complex, STV alone and Mixture of STV and CpG.
Over a period of 70 days, the team found that mice injected with the full vaccine complex developed immune response nine-fold higher than those with CpG and STV mixture and the pyramid shaped structures yielded the best immune response. This holds great potential for the development of targeted therapeutics.