Conventional and Tropism-Modified High-Capacity Adenoviral Vectors Exhibit Similar Transduction Profiles in Human...

Area of Science:

• Ophthalmology
• Gene Therapy
• Molecular Biology

Background:

• Adeno-associated viral vectors (AAV) are standard for retinal gene therapy but have limited cargo capacity.
• This limitation restricts the delivery of large therapeutic genes for retinal diseases.

Purpose of the Study:

• To evaluate high-capacity adenoviral vectors (HC-AdVs) for delivering large retinal genes.
• To assess the tropism and safety of HC-AdVs in human retinal organoids.

Main Methods:

• Engineered HC-AdVs (AdV5 and AdV5.F50) to deliver a 29.6 kb reporter construct.
• Tested HC-AdV tropism and transduction efficiency in iPSC-derived retinal organoids.
• Monitored transgene expression and retinal cell health for up to 110 days.

Main Results:

• Both HC-AdV types demonstrated robust transduction efficiency and sustained transgene expression.
• Efficient transduction of photoreceptors and Müller glial cells was observed.
• No reactive gliosis or photoreceptor cell loss occurred, but outer nuclear layer thickening was noted at 110 days.

Conclusions:

• HC-AdVs are a feasible alternative for large gene delivery in retinal gene therapy.
• Further research is needed to confirm long-term safety and efficacy, addressing potential adverse effects.
• HC-AdVs offer potential for treating retinal diseases currently limited by AAV cargo capacity.