Imaging Transplanted Photoreceptors in Living Nonhuman Primates with Single-Cell Resolution

Area of Science:

• Ophthalmology
• Regenerative Medicine
• Stem Cell Biology

Background:

• Retinal degenerations are a leading cause of blindness.
• Current treatments are limited, with stem cell therapy showing promise.
• Preclinical research primarily uses rodent models, which have limited translational value.

Purpose of the Study:

• To establish a nonhuman primate experimental platform for photoreceptor replacement therapy.
• To develop methods for noninvasively tracking transplanted cells in vivo.
• To assess the survival, migration, and integration of human embryonic stem cell-derived photoreceptors in a primate model.

Main Methods:

• Developed an experimental platform using nonhuman primates.
• Utilized fluorescence adaptive optics scanning light ophthalmoscopy (FAOSLO) for in vivo cell tracking.
• Transplanted fluorescently labeled human embryonic stem cell-derived photoreceptors into macaque retinas.
• Employed ultrafast laser ablation to create photoreceptor-deficient areas for transplantation.

Main Results:

• Successfully tracked transplanted photoreceptor precursors in vivo using FAOSLO.
• Demonstrated survival and migration of transplanted cells.
• Observed potential integration and neurite formation of photoreceptors in the macaque retina.
• Histology suggested migration to the outer plexiform layer and possible synapse formation.

Conclusions:

• The developed platform enables noninvasive monitoring of stem cell transplantation in a primate model.
• This research provides a more translatable preclinical model for retinal degeneration therapies.
• Further investigation is warranted to confirm functional integration and therapeutic efficacy.