Exploiting internal ribosome entry sites in gene therapy vector design.

Area of Science:

• Biotechnology
• Molecular Biology
• Gene Therapy

Background:

• Co-expression of multiple genes is crucial for treating complex diseases like cancer and infections (e.g., HIV-1).
• Gene therapy vectors often require co-expression of therapeutic and selectable marker genes for sustained expression.
• Internal ribosome entry site (IRES) elements facilitate cap-independent translation initiation for coordinated gene expression.

Purpose of the Study:

• To review naturally occurring and synthetic internal ribosome entry site (IRES) elements.
• To examine the potential of IRES elements in gene therapy vector design.
• To address limitations of current IRES elements, such as inefficient downstream gene expression.

Main Methods:

• Literature review of existing and novel IRES elements.
• Analysis of IRES function in gene therapy vector contexts.
• Comparison of IRES efficiency and characteristics.

Main Results:

• Internal ribosome entry site (IRES) elements enable coordinated translation of multiple genes from a single transcript.
• The encephalomyocarditis virus (EMCV) IRES is widely used but shows unequal expression of upstream and downstream genes.
• A diverse range of natural and synthetic IRES elements exist with varying efficiencies.

Conclusions:

• Internal ribosome entry site (IRES) elements are promising tools for multi-gene expression in gene therapy.
• Further research into novel and modified IRES elements is needed to overcome current efficiency limitations.
• Optimized IRES-based vectors can enhance the efficacy of gene therapies for complex diseases and infectious agents.