Ribozyme gene therapy for hepatitis C virus infection

Area of Science:

• Molecular biology
• Virology
• Gene therapy

Background:

• Hepatitis C virus (HCV) poses a significant challenge due to its high mutation rate, leading to drug resistance in antiviral therapies.
• Ribozymes (Rz) are RNA molecules with enzymatic activity that can be engineered to target specific RNA sequences.
• Gene therapy offers a continuous intracellular supply of Rz, potentially preventing the emergence of drug-resistant viral variants.

Purpose of the Study:

• To investigate the use of viral vectors for delivering ribozyme genes directly into hepatocytes of HCV-infected patients.
• To degrade the HCV genome and viral mRNAs by targeting multiple conserved RNA sequences simultaneously, thereby circumventing drug resistance.

Main Methods:

• In vitro transcription of Rzs targeting conserved HCV RNA sequences.
• In vitro cleavage assays using Rzs to degrade HCV target RNAs.
• Incorporation of effective Rzs into adeno-associated viral (AAV) and adenoviral (AV) vectors.
• Testing Rz-expressing viral vectors in tissue culture to inhibit HCV core gene expression.

Main Results:

• Several Rzs demonstrated effective degradation of both positive and negative strands of HCV RNA in vitro.
• Viral vectors successfully delivered Rz genes into cells, leading to substantial inhibition of HCV gene expression in tissue culture.

Conclusions:

• Ribozyme gene therapy presents a viable strategy for developing novel anti-HCV drugs.
• Initial studies indicate success in using Rz gene therapy to produce antiviral effects against HCV.
• This approach may offer a solution to the challenge of drug-resistant mutant emergence in HCV therapy.