From the time they joined Professor Seiler’s research group, Tej Kalakuntla and Johanes Santoso have been encouraged to pursue independent work. They proposed the research presented here and gained the experience of being involved in a project from its very beginning. Both Tej and Johanes are planning to continue on to medical school after graduation and feel that their work in Professor Seiler’s lab has helped them move toward that goal.

Nearly half of the vision related diseases in Western society are due to retinal degeneration. Most studies aim to prevent vision loss by treating early stages of retinal degeneration, but once the diseases progress and photoreceptors and retinal pigment epithelium (RPE) have late-stage degenerated, they need to be replaced with new cells. This study focuses on the hypothesis that sub-retinal transplantation of embryonically derived retinal progenitor sheets will lead to a restoration of photoreceptors and visual acuity in Royal College of Surgeons (RCS) rats that have a genetic defect in the RPE that leads to almost complete degeneration of their photoreceptors. Sub-retinal transplants were placed in the blind rats at the age of 7–8 weeks and were allowed to develop anywhere from 50 to 300 days before the rats were perfused. Testing was done by sectioning the eyes of RCS rats with transplant surgery. The sections were then stained and analyzed to demonstrate the presence of photoreceptors after transplantation. We found that, post-transplantation, RCS rats that would normally be without photoreceptors had significant numbers of rod and cone cells. These cells were then found to be associated mostly with the transplanted region, which was especially true in rats with late stage degeneration. Overall, it was clear that the hypothesis was supported.

Magdalene Seiler School of Medicine

Tej Kalakuntla and Johanes Santoso analyzed retinal transplants to Royal College of Surgeons rats, a model of retinal degeneration, using a variety of antibodies and staining methods. Most retinal sheet transplants were derived human embryonic stem cells that had been developed into retinal organoids. Transplants were analyzed 2–7 months after transplantation. The data show that transplants develop new photoreceptors and integrate with the host retina. The students learned to work together as a team, as most experiments take longer time than 4 hours per day. They also learned how to troubleshoot experiments. Both students are heading for Medical School. Tej has already been accepted and Johanes will try to get to Medical School in the fall of 2020.