Better targeting, better efficiency of Adeno‐associated virus gene transfer in the Central Nervous System for expression of Retromer proteins

Abstract

Researchers are using AAV gene transfer more and more in their neuroscience studies, including optogenetics, cre‐lox targeting, and CRISPR gene editing. Our lab has been using the AAV9 vector serotype to express genes on a wide‐scale basis throughout the central nervous system in order to study a disease that affects cells throughout the central nervous system, amyotrophic lateral sclerosis. This current project explored ways to achieve more efficient expression and in a more targeted manner than our previous work. The recently described AAV PHP.B serotype was administered to rats for the first time, and it did result in significantly more green fluorescent protein expression than did the AAV9 vector in a systematic comparison. In studies comparing the neuron‐specific synapsin promoter with our previous cytomegalovirus/ chicken β‐actin promoter, the latter promoter was noticeably more efficient yet the synapsin promoter did yield a transduction pattern with greater neuron‐selectivity, which was the goal. We also explored intracerebroventricular injections to achieve wide‐scale transduction and better avoid unwanted transduction of peripheral organs. We are combining the synapsin promoter in AAV PHP.B vectors to take advantage of these efficiency and targeting features. Our specific genes of interest that we wish to express are called the retromer proteins. Retromers make up a protein complex that is associated with the trafficking of cellular vesicles through the endosome and the trans‐Golgi network. Viral constructs were made for epitope tagged versions of the retromers VPS29 and VPS35. We hypothesize that the retromers can act to prevent the formation of beta‐amyloid plaques in Alzheimer's disease by altering the trafficking of amyloid precursor protein.Support or Funding InformationDr. Ronald Klein, Kasey Jackson, Robbie Dayton, Fidelity Biosciences Research Initiative, Karyopharm Therapeutics, Inc., ALS Association, Meira GTx, The LSU Health Sciences Center Foundation in Shreveport, The American Society for Pharmacology and Experimental Therapeutics, The Society for Toxicology