A novel anti-viral delivery system
Creators: name: University Of California Office Of The President
Publisher: name: University of California Office of the President
publisherIdentifier: https://ror.org/00dmfq477
publisherIdentifierScheme: ROR
Year: 2024

description: This is a pilot project proposing to develop a completely new way to deliver antiviral drugs that will minimize the emergence of drug-resistant virus strains during therapy. One constant threat to the control of AIDS and opportunistic infections is the appearance of drug-resistant strains of HIV and opportunistic infectious agents, including viruses such as CMV, which causes eye and brain infections. One approach being used now to minimize the selection of resistant strains is combination therapy. The rationale is that in combination therapy, the probability of simultaneous development of multiple mutations in a virus that confer resistance to all the drugs is low. However, this approach is complicated by drug toxicity, drug interactions, and expense. A radically new way to inactivate HIV and other viruses without selecting resistant strains is needed. This IDEA Award pilot project seeks to develop such a new approach. About 30 years ago, researchers discovered that small pieces of DNA or RNA can inactivate target RNA, including RNA of viruses. Since RNA molecules are needed by just about all organisms, they can serve as potential targets to kill viruses. There is a group of RNA molecules called ribozymes made by all types of cells that have an enzyme activity against other RNA molecules. These ribozymes have been successfully used to inactivate a variety of viruses inside artificially grown cells. Since RNA molecules can have many different sequences, they offer unlimited potential targets for inactivation by ribozymes. The major hurdle, however, is in figuring out how to deliver ribozymes into virus-infected cells in a human or animal host. Ribozymes will not enter cells with high efficiency unless they are attached to some type of carrier, such as another virus. The use of viruses as carriers, especially for those with AIDS, is not acceptable. We have identified a small piece of protein (peptide) made of only 22 amino acids that can cause anything attached to it to enter cells. This peptide called Inv3 was actually identified in a protein that allows a bacterium that causes tuberculosis to enter cells. We have devised a simple, inexpensive method to attach any protein to Inv3 to deliver the protein into cells. It turns out one of the highly potent ribozymes called RNA P has a protein component (P) that can be redesigned to incorporate Inv3. This will allow RNA P to enter cells on its own. RNAse P has a small piece of RNA called external guide sequence (EGS) that can be synthetically modified to target any sequence in a piece of viral RNA. Thus, the same part of RNAse P (enzymatically active RNAse) can be made with many different EGS pieces to target many different RNA sequences of the same virus. Thus a cocktail of RNAse P can be made cheaply and used to inactivate viruses with greatly reduced chances of selecting drug resistant strains. In this pilot project, we wish to optimize this RNAse P delivery system and test it to inactivate CMV that causes opportunistic diseases in AIDS patients as a proof-of-the-concept study. We will first test it in cultured cells, and if successful, we will test it to inactivate CMV in mice. If we show that it can inactivate CMV in mice, this technology should offer a wide application, including using it to inactivate HIV. The ability to inactivate HIV without selecting drug resistance should make a major contribution to the control of AIDS in California and elsewh