Developing Cutting-edge Genetic Technology to Treat Alzheimer’s Disease

By Mona Cumaran and Sahil Malhotra

In the past year, 130,000 people have died from Late Onset Alzheimer’s Disease (LOAD), and the pandemic has increased this rate by almost 20%. This debilitating neurodegenerative disease revokes one’s awareness and autonomy and places the burden of care on 11 billion unpaid caregivers. While there is no cure, several genes (i.e. APOE4) can increase the risk of developing LOAD. Gene therapy is an innovative tool that offers direct therapeutic effects on LOAD patients significantly improving quality of life.

Our names are Mona Cumaran and Sahil Malhotra; two juniors who are interested in medicine. We joined the Gene Therapy for Alzheimer's Disease and Ethical Aspects of Genome Editing team our freshman year to develop cutting-edge genetic technology to treat LOAD. We are fascinated by CRISPR gene-editing technology and, more importantly, passionate about developing a therapy that can eliminate the devastating effects of LOAD and other neurodegenerative diseases. A crucial tool for gene therapy is the adeno-associated virus (AAV), which can carry a therapeutic “gene payload” into affected cells. However, packaging a payload into an AAV isn’t straightforward: the small size of AAVs restricts the maximum payload size and makes the process inefficient. We hoped that by directly fusing a payload to the VP2 protein, located inside the AAV capsid (viral shell), we could surpass the current limitations of AAV packaging — and ultimately build a more powerful system for delivering gene therapy.

The project pushed us out of their comfort zone and developed critical thinking and problem-solving skills. We had initially planned on a split intein system to optimize AAV packaging, but based on input from our team leader, we switched to the new VP2 approach. Designing and building custom viral vectors required us to develop a wide variety of molecular biology skills, and technical troubleshooting, such as quantifying GFP (on the left), optimizing transfection ratios, and using multiple AAV serotypes, was present at every step. Despite these challenges, working as a team and getting valuable mentorship helped paved the way for successful results. The project has taught us to persevere and think creatively to develop solutions.

There were many times where cells did not express GFP, an indicator of successful plasmid recombination, but with the help of the mentors and continuous support from lab members, we identified alternative assays and different experimental conditions. The team was welcoming and gave us the creative independence and leadership in the project, which is often not given to many undergraduates. This project was rewarding and fulfilling for us. Every other day, we analyzed new results, investigated anomalies, and planned our next experiments. We are planning to continue this project into next year with the hopes that one day, an effective and viable gene therapy can be offered to patients at risk of developing LOAD.