Year 3

The present project aims at developing a large animal model to test new stem cell therapies for neurological conditions that cause loss of motor neurons. Such conditions include spinal cord injury to the sacral portion of the spinal cord, also known as the conus medullaris, and amyotrophic lateral sclerosis (ALS). For this purpose, we are developing techniques to inject human embryonic stem cells into the spinal cord of non-human primates. The cells have first been cultured in petri dishes to develop properties of motor neurons. The animals also are treated with a new protocol for immunosuppression that has eliminated the needs for oral medications and instead are injected intravenously or under the skin. The injectable anti-rejection medications are able to result in more stable blood levels of the medications and are better tolerated as they can reduce side effects such as nausea. The project is progressing well. Initial studies have shown ability to inject cells into the appropriate target areas of the spinal cord where motor neurons normally reside. The subjects have demonstrated treatment levels of immuno-suppression in the blood, and transplanted cells have survived and integrated well in the spinal cord. We are presently performing longer-term studies to evaluate the ability for the subjects to tolerate immuno-suppression administrated by injection over longer study periods periods and for cells to survive over longer time periods. We are also monitoring the subjects for potential adverse effects, including pain and tumor growth over several months. Our request for a o-cost time extesion will allow us to complete these studies and original goals. Next steps after the present project has been completed will aim to use this new research tool to evaluate for possible positive effect on neurological function in a larger group of non-human primates before translating this cellular treatment form to a human population in clinical studies.