Chemogenetic ON and OFF switches for RNA virus replication.

Area of Science:

• Virology
• Molecular Biology
• Gene Therapy

Background:

• Therapeutic RNA viruses (oncolytic agents, gene vectors) require strict activity control to manage toxicity.
• Existing methods for controlling viral activity are limited.

Purpose of the Study:

• To develop a novel conditional protease-based regulator switch for RNA viruses.
• To enable precise, on-demand control over viral transcription and replication.

Main Methods:

• Engineered vesicular stomatitis virus (VSV) genomes by incorporating a human immunodeficiency virus (HIV) protease dimer.
• Linked essential viral proteins (P or L) to the HIV protease activity.
• Utilized HIV protease inhibitors to modulate viral activity.

Main Results:

• An "ON" switch was achieved by integrating the HIV protease dimer into VSV's P or L protein, requiring protease inhibitor for activity.
• A "OFF" switch was created with an N-terminal VSV polymerase tag and HIV protease dimer, where inhibitor application halted viral activity.
• Demonstrated dose-dependent control of virus activity via protease inhibitors.

Conclusions:

• A conditional protease regulator switch for RNA viruses was successfully developed.
• This technology offers precise, tunable control over therapeutic RNA virus activity.
• The approach shows potential applicability to other therapeutic RNA viruses.