Recently, plasmid DNA vaccines have been developed for diseases like influenza, hepatitis B, HIV and cancer. Some DNA vaccines, like the cancer associated antigen carcinoembryonic antigen (CEA), have high protection rates against in vitro challenge with a human breast cancer cell line. However, potential dangers involved with DNA vaccines has lead to investigating the feasibility of RNA vaccines. Detectable immune responses have been produced in mice immunized with mRNA encoding influenza virus nucleoprotein nd encoding CEA. These promising results warrant continued research. The 5' cap [m7G(5')ppp(5')G] of mRNA is important in maintaining mRNA stability and promoting the efficient translation of mRNA. Thus, RNA vaccines should be composed of 100% capped transcripts. Currently, the best methods for synthesizing capped RNA produce much lower yields compared to uncapped RNA. Optimizing the conditions for generating high yields of capped RNA will become an important factor when converting from the lab bench to large scale production. Our other goal is to develop procedures and conditions to produce pure, full length, capped RNA acceptable for human use. We will meet these goals by optimizing the capping reaction conditions and developing innovative technologies for purifying capped RNA.
This research may lead to the development of inexpensive kits, commercially available for synthesizing capped RNA for translation experiments. The long term goal is to produce human therapeutic RNAs, especially for cancer vaccines, but also including anti- sense RNA and ribozymes.
