The Effects Of Serotypes And Route Of Administration On Transduction Efficiency For Aav-Mediated Gene Delivery To The Cns

Introduction: The recent advances in gene-therapy have enabled clinicians to treat diseases that were once deemed untreatable without any effective treatment modalities. Modulation at the genetic level was once thought to be impossible. However, advances such as using recombinant adeno-associated viruses (rAAV), which are viruses that have been re-engineered to be used as a vehicle for transport and subsequent transduction have opened new horizons in replacing defective and under expressed proteins. Various rAAV have been engineered, each with differing susceptibility to different tissues.Methods: In this experiment, we tested all of the aav's available on the market (AAV1, 2, 5,6,7 & 8) with both injection directly into the spinal cord as well in the major muscles (triceps, quadriceps and gastrocnemius) of Naive C57BL/6J mice. The aav were constructed to express Green Fluorescent Protein (GFP). We analyzed brain and spinal cord from animals harvested at 6 weeks, 6 months and 1 year time point. Using qualitative and quantitate analysis with Immunofluorescence and qPCR, we determined the most efficient AAV type for intraspinal and Intramuscular injection.Result: When measuring Immunofluorescence and qPCR, aav 8 showed the highest transduction of GFP in Intraspinal injection. It also showed high levels of GFP in the spinal cord following intramuscular injection, though qPCR levels were not significant.Discussion: AAV 8 showed a high level of CNS transduction with both immunofluorescent as well as qPCR, showing a preferential transduction capacity in the CNS which may be applicable in treating primary CNS disorders.